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A Xerox Education C o m p a n y SCHOFIELD, Jr., Edmund Acton, 1938- £ FIELD AND LABORATORY STUDIES ON THE ECOLOGY AND | PHYSIOLOGY OF SELECTED ALGAE, MOSSES, AND LICHENS I FROM ANTARCTICA.

The Ohio State University, Ph.D., 1972 || Botany

§ University Microfilms, A XEROX Company, Ann Arbor, Michigan

THIS DISSERTATION HAS BEEN MICROFILMED EXACTLY AS RECEIVED. FIELD AND LABORATORY STUDIES ON THE ECOLOGY AND

PHYSIOLOGY OF SELECTED ALGAE, MOSSES, AND

LICHENS FROM ANTARCTICA

DISSERTATION

Presented in Partial Fulfillm ent of the Requirements for the Degree Doctor of Philosophy in the Graduate School of The Ohio State University

By

Edmund Acton Schofield, J r ., B.A., M.A.

*****

The Ohio State University 1972

Approved by

Adviser Department of Botany PLEASE NOTE:

Some pages may have

indistinct print.

Filmed as received.

University Microfilms, A Xerox Education Company ACKNOWLEDGMENTS

Some of the laboratory work reported herein was done in the

Department of Biology, Clark University, Worcester, Massachusetts, with support from the Office of Antarctic Programs, National Science Founda­ tion, Grant GA-36 to Dr. Vernon Ahmadjian. Most of the laboratory analyses and a ll of the fie ld studies were completed while the author was a graduate research assistant in the Department of Botany and

Institute of Polar Studies at The Ohio State University. Financial support was provided by National Science Foundation Grant GA-840 to

Dr. Emanuel D. Rudolph.

Dr. Carroll W. Dodge, University of Vermont, Burlington, kindly identified a ll lichen specimens sent him; his ready cooperation was crucial to the success of this study. Dr. Stanley W. Greene, University of Birmingham, England, kindly id en tified the moss specimen, and Dr.

Jacques S. Zaneveld, Old Dominion College, Norfolk, Virginia, identified specimens of algae.

Mr. Keith A. J. Wise, now of the Auckland In stitu te and Museum,

Auckland, New Zealand, donated many lichen specimens and aided greatly by suggesting collecting sites fo r lichens. His advice and companionship in the fie ld were invaluable. Messrs. Paul R. Theaker, Ray E. Showman, and Joseph B. Harvey assisted during the 1967-1968 and 1968-1969 fie ld seasons, and Mr. Harvey also aided with some o f the la te r laboratory work. Mr. Kelvin P. Rennell collected several specimens in West

i 1 Antarctica and in V ictoria Land, including the specimen of Lecanora

tephroeceta used in the nitrogen and temperature studies, and Drs.

Yosio Kobayasi, National Museum of Science, Tokyo, and Emanuel D.

Rudolph, The Ohio State University, donated specimens from Ross Island

and Victoria Land. Mr. Robert C. Wood of The Johns Hopkins University

kindly provided specimens of Xanthoria si piei from Cape Crozier; he

also provided the aerial photograph of "Sugarloaf Ridge."

Miss Beverley A. Temple aided in the inoculation procedures and

generously lent her assistance in many other ways, while Mrs. Angharad

Holmes and Mr. Henry Adelman provided invaluable guidance on the microkjeldahl analyses.

The topographic maps o f Quadrats I and IV were produced by Messrs.

K. Eissinger, R. Todd, F. BrownswortH, and K. Anderson, United States

Geological Survey topographic engineer?. I wish to record my sincerest appreciation of their efforts in my behalf.

The officers and men of U. S. Naval A ir Development Squadron Six

(VX-6) provided excellent logistic support in the field. I wish specifically to acknowledge the assistance of Mr. R. Martin (PH 2) for his assistance with the aerial photography. The support of U. S. Navy

Deep Freeze personnel is also gratefu lly acknowledged, p articularly that of Mr. J. K. T. Craig (PH 2) and Mr. H. Steiner (PH 2).

I wish to reserve my special thanks to the s ta ff of the In stitu te of Polar Studies, who have assisted me in countless ways since the beginning of the 1967-1968 phase of the study, and for the Department of Botany, which has permitted me to use its fa c ilitie s for.much of the laboratory work and which underwrote a large proportion of the cost of preparing the dissertation. In particular, I wish to acknowledge the generous assistance and advice of Professor Emanuel D. Rudolph,

Dr. Morris G. Cline, Dr. Gary B. Collins, and Dr. Roland L. Seymour, who read the dissertation at various stages in its development, and to

Dr. John A. Schmitt, J r ., for approving financial assistance by the

Botany Department fo r photography and Xeroxing. Mr. John F. Spletts- toesser assisted during all phases of the project in his capacity as

Associate Director of the Institute of Polar Studies, and Mrs. Jeanne M.

Peebles lent invaluable aid during the preparation of the dissertation.

Mr. Herbert Mehrling prepared equipment and supplies for shipment to

Antarctica for the last two field seasons.

F in ally, I wish to acknowledge the patience and endurance of my two typ ists, Mrs. Kay Wagner and Miss Dorothy Amrine. Only they re ally know the full story. VITA

November 26, 1938 ...... Born - Worcester, Massachusetts

1962 ...... A. B. (Biology), Clark University, Worcester, Massachusetts

1962-1963 ...... Teaching Assistant-Scholar, Depart­ ment of Biology, Clark University, Worcester, Massachusetts

1963-1964 ...... Field Assistant, United States Antarctic Research Program

1964 ...... M. A. (Biology), Clark University, Worcester, Massachusetts

1965-1967 ...... Technical Editor, Reports Depart­ ment, B attelle Memorial In s titu te , Columbus, Ohio

1967-1972 ...... Graduate Research Associate, In s ti­ tute of Polar Studies, The Ohio State ■ University, Columbus, Ohio

1967-1968 ...... Field Assistant, United States Antarctic Research Program

1968-1969 ...... Field Assistant, United States Antarctic Research Program

1970 ...... Teaching Assistant, Department of Botany, The Ohio State University, Columbus, Ohio

1972 ...... Assistant to the Director, Institute of Polar Studies, The Ohio State Uni­ versity, Columbus, Ohio (January through May)

v PUBLICATIONS

"Probable Damage to Tundra Biota through Sulphur Dioxide Destruction of Lichens." Biological Conservation 2(4): 278-280 (July 1970) (with Wayne L. Hamilton]"!!

"Probable Damage to Arctic Ecosystems through A ir-Pollution Effects on Lichens." Science in Alaska (Proc. 20th Alaska Science Conference, College, Alaska, 24-27 August 1969), pp. 271-291 (with Wayne L. Hamilton).

FIELDS OF STUDY

Major Field: Botany

Studies in Botany (Lichenology). Dr. Vernon Ahmadjian

Polar Studies and Lichenology. Dr. Emanuel D. Rudolph

Studies in Marine Botany. Dr. Richard C. Starr

Studies in Ecology. Dr. Gareth E. G ilbert and Dr. Charles H. Racine

Studies in Ecosystems Analysis and Modelling. U. S. International Biological Program Tundra Biome Program, Barrow, Alaska TABLE OF CONTENTS

Page

ACKNOWLEDGMENTS ...... i i

VITA ...... v

LIST OF TABLES v iii '

LIST OF CHARTS ...... x

LIST OF FIGURES ...... X

LIST OF GRAPHS ...... xi

LIST OF MAPS x iii

INTRODUCTION . . . v. . . . • ...... 1

Purpose of the Present Study • Terrestrial Ecosystems ‘ Physical and Biogeography of Antarctica

DESCRIPTION OF FIELD AND LABORATORY STUDIES ...... 13

Experimental Laboratory Studies Field Studies Sandstone Study * Results of the Field Studies Results of the Laboratory Analyses Results of the Sandstone Study

DISCUSSION...... 234

Soils Importance of Nitrogen in the Environment

CONCLUSIONS...... 259

SUMMARY...... 261

BIBLIOGRAPHY...... 262

v i i LIST OF TABLES

Table Page

1 Habitat Data for all Available Collections of Lecanora tephroeceta Hue from West Antarctica ...... 16

2 Growth of Lichen "A" Mycobiont (Lecanora tephroeceta) at Twelve pH Values Between pH 4.0 and pH 8 . 4 ...... 29

3 Growth Attained by the Mycobiont Lecanora tephroeceta Hue on Various Sources of Nitrogen in Buffered Medium. . 30

4 Growth of Prasiola crispa from the Balleny Islands on Various Nitrogen Sources and with Added Growth Factors ...... 50

5 Growth of a ll Eight.Clones of Bruym a1 gens Cardot on Various Media (Experiment 1) ...... 59

6 Growth of Five Clones of Bryum a!gens Cardot on Soil-Water Medium with Various Additives (Experiment 2) ...... 62

7 Growth of Clone 6 of Bryum algens Cardot on B ristol's Solution Agar Containing Various Nitrogen Sources and Additives (Experiment 3 ) ...... 66

8 Program o f Environmental Observations Made at All Quadrats ...... 131

9 Summary of Observational Periods During Both Field S easo n s...... 132

10 Global Radiation Intensity at the Quadrats ...... 147

11 Moisture Contents of Soils in Relation to the Occurrence of Plants ...... 183

12 Moisture Contents of Soils Collected Under and Near Algae Growing Near Quadrats I , I I , and I l i a ...... 189

13 Partial Analysis of Some Soil Samples' From Ross Island and Victoria Land ...... 193

14 Nitrogen Contents of Bird Droppings, Guano, and Associated Soils ...... 199

v i i i LIST OF TABLES (continued)

Table Page

15 Nitrogen Contents of Water Samples ...... 200

16 Urea Contents of Water and Soil Samples from Ross Is la n d...... 203

17 Comparison of the Nitrogen Contents of Soils Associated with Plants and of Soils Not Associated with Plants ...... 204

18 Comparison of the Nitrogen Contents of Algae, Mosses, and Lichens and of Their Associated Soils ...... 207

19 Total Nitrogen Contents of Blue-Green Algae from Ross Island, McMurdo Sound, and Southern Victoria Land and of Their Associated Soils ...... 208

20 Nitrogen Contents of Mosses from Ross Island, McMurdo Sound, and Southern Victoria Land and of Their Associated Soils ...... 210

21 Nitrogen Contents of Lichens and of Their Associated Substrates , . i ...... 213

22 Albedos of Dolerite and Sandstone Surfaces on Kar Plateau 233

23 Occurrence in Antarctica of "Phormidium autumnale," an Unsheathered Aquatic Ecophene of Microcoleus vaginatus (Vaucher) Gomont, as Determined from Herbarium Specim ens ...... 249

ix LIST OF CHARTS

Chart Page

I Suggested pathways by which the 38 nitrogen sources were absorbed and assimilated by the mycobiont Lecanora tephroeceta Hue in the laboratory experiments ...... 39

II Provisional flowchart of the movement of nitrogen through Cold Desert ecosystems ...... 220

LIST OF FIGURES

Figure / . Page

1 Clonal isolate of Bryum a 1 gen's from the Jones Mountains, Eights Coast, East Antarctica, in axenic culture ( c f. Gressitt et al_.,1964) . . . ., ...... 57

2 Oblique aerial photograph of Kar Plateau (le ft) and Dreikanter Head (right) from the east ...... 90

3 A composite of two aerial photographs of the southeastern corner of Kar Plateau ...... 92

4 Enlargement of part of Figure 3 showing the location of Quadrat IIlb (indicated by the black and white c ir c le s )...... 96

5 Distribution of lichens (prim arily Caloplaca elegans var. pulvinata (Dodge and Baker) Murray, a nitrophilous species) parallel to the edge of a permanent snowdrift near Cape Royds sim ilar to that in Quadrat I for which nitrogen content and conductance values were determined ...... 104

6 Arrangement of a Bellani Pyranometer in Quadrat I . . . 142

7 Belfort recording pyrheliograph, mounted in a horizontal position and secured in place with ropes and rocks near Quadrat I ...... 145

x LIST OF FIGURES (continued)

Figure Page

8 The approximate locations (dots) at which soil samples were collected along two perpendicular transects through the center of the sandstone deposit on Kar P la t e a u ...... 163

9 Soil-moisture sites in and near Quadrat I ...... 168

•LIST OF GRAPHS

Graph Page

I Distribution of inoculum weights in the nitrogen-source experiment with the mycobiont Lecanora tephroeceta Hue . 22

I I Growth of the mycobiont Leeidea sp. (Ahmadjian #32) in liquid medium at. various pH values ...... 25

I I I A typical growth curve for the mycobiont Lecidea sp. (Ahmadjian #32),at pH 5.0 ...... 27

IV Growth of the mycobiont Lecanora tephroeceta Hue on 38 nitrogen sources, arranged according to class of nitrogen compound ...... 33

V Growth of the mycobionts Lecanora tephroeceta Hue (Lichen A) and Lecidea sp. (Ahmadjian #32) (Lichen B) at various temperatures ...... 41

VI Ranges of conductance values obtained with 2:1 aqueous extracts of soil samples collected on Ross Island and in the McMurdo Sound region of southern Victoria Land . 165

V II Soil-moisture contents at Sites RM 1 through RM 5 in Quadrat I from 26 December 1968 through 29 December 1968 ...... 169

V III Soil-moisture contents of Sites CM 1 through CM 6 in and near Quadrat I I at various times on 9 January 1968 . 171

x i LIST OF GRAPHS (continued)

Graph Page

IX Soil-moisture contents at Sites CM 1 through CM 3 and a t Site CM 6 in and near Quadrat I I at various times from 20 to 23 January 1968 ...... 173

X Soil-moisture content at Site CM 5 in Quadrat II from 11 to 15 December 1968 ...... 174

XI Soil moisture and surfact temperature at three sites in Quadrat Il ia on 6 and 7 January 1968 ...... 176

XII Soil moisture at Quadrat IIlb from 21 to 25 November 1968 ...... 177

XIII Moisture contents of soils in Quadrat IV during two periods of the 1968-1969 austral summer ...... 178

XIV Conductance of 2:1 aqueous extracts of the soil samples collected along the two 280-m-long, mutually perpendicu­ la r transects through the center of the sandstone deposit on Kar P la te a u ...... 223

XV Wet- and dry-bulb temperatures in the sandstone deposit on Kar Plateau and in the dolerite downwind of the sand­ stone (top) and the relative humidity calculated for the same areas (bottom) ...... 225

XVI Relative humidity about 3 cm above a soil net and a trough in the sandstone deposit (A and B, respectively) and in the dolerite area downwind of the sandstone (C and D, r e s p e c tiv e ly ) ...... 227

XVII A ir temperatures at a height of 5 cm over the center of soil nets (circles ) and over troughs (squares) in the sandstone area on Kar Plateau (broken lines) and in the dolerite area downwind of the sandstone (solid lines) ...... 229

X V III Rock, lichen, and soil-surface temperatures in Quadrat Illb (solid symbols), in the sandstone (open symbols connected with broken lin e s ), and in the dolerite area downwind of the sandstone (open symbols connected with solid lines) on 28-31 January 1969 . . . 231

x i i LIST OF MAPS

Map Page

I Botanical regions of Antarctica according to Korothevich (Soviet Antarctic Expedition, 1966), based on findings of Soviet expeditions and on sources from the litera tu re ...... 6

II Distribution of plants in Maritime and Continental Antarctica ...... 7

I I I The "McMurdo Oasis" of southern Victoria Land ...... 10

IV Map showing the location of Sabrina Island (arrow), collection site for, the Prasiola crispa used in the nitrogen-source experiment ...... 45

V Map of the McMurdo Sound area of East Antarctica showing the locations of Quadrats I through IV .... . 82

VI Contour map of Cape Royds, Ross Island, and v ic in ity . . 84

V II Map of the Cape Crozier and Williamson Rock regions of Ross Island ...... 86

V III The Granite Harbor region of southern Victoria Land . . 88

IX The approximate wind-flow pattern in the western Ross Ice Shelf—Ross Island and southern Victoria Land region (lines and arrows) ...... 110

X Map of Ross Island showing the locations of the known penguin rookeries ...... 117

XI Contour map of "Sugarloaf Ridge" showing the approximate location of Quadrat I I (stippled square) . . 119

XII The distribution of the fruticose lichen Usnea (Neuropogon) antarctica in relation to the sandstone deposit on Kar Plateau ...... 123

xi i i LIST OF PLATES

Plate Page

I Kar Plateau as seen from the south at the base of The Flatiron (A), and a view of Quadrat Ilia from the southwest (B ) ...... 94

I I Miers Valley from the east (A) and Quadrat IV from the south ( B ) ...... 99

I I I Aerial photograph (A) and contour map (B) of Quadrat I , Cape Royds region, Ross I s l a n d ...... 102

IV Occurrence of mosses in polygon troughs near Quadrat I , Cape Royds region, Ross Island ...... 107

V Aerial photographs of the v ic in ity of Quadrat I immediately'after a 5-day blizzard (A) and a longer but unknown length of time a fter snowfall (B) 113

VI "Sugarloaf Ridge" from the a ir (A) and from the south (B) ...... 115

V II Map and aerial photographs of the Miers Valley area in extreme southern Victoria Land, showing the location of Quadrat IV ...... 126

V III Miers Glacier (A) and "Miers Stream" ( B ) ...... 128

IX A Yellow Springs Instruments Tele-Thermometer in its protective housing (A), and the arrangement of the temperature probes (B) ...... 136

X Photographs of an area of alg al, lichen, and moss growth in Quadrat I l i a ...... 181

XI Two photographs of mosses (A) and (B) near Capes Royds and Crozier, respectively, showing that these plants map increase the moisture and lower the temperature of the soil microhabitat beneath them by intercepting the flow of heat ...... 191

x iv FIELD AND LABORATORY STUDIES ON THE ECOLOGY AND

PHYSIOLOGY OF SELECTED ALGAE, MOSSES, AND

LICHENS FROM ANTARCTICA

By

Edmund Acton Schofield, J r ., Ph.D.

The Ohio State University, 1972

Professor Emanuel D. Rudolph, Adviser

INTRODUCTION

Purpose of the Present Study

The present fie ld and laboratory study was designed to assess the relative importance to the distribution of te rre s tria l Antarctic plants of as many environmental factors—both physical and b io tic —as possible, by monitoring several meteorological, micrometeorological, and edaphic parameters during two summer fie ld seasons in the McMurdo Sound region of East Antarctica. In addition, another field season had previously been spent collecting plants and isolating organisms into laboratory cultures.

Five permanent quadrats were set up in four widely scattered lo c a litie s on Ross Island and in southern Victoria Land. In the laboratory, s o il, water, and plant samples were analyzed to complement the fie ld data. The organisms, lo c a litie s , and environmental parameters were selected for study on the basis of the f ir s t fie ld season's observations, information found in the scientific literature on

Antarctic te rre s tria l ecosystems and organisms, and logistics considerations.

The "null hypothesis" to be tested was that the quantity and types of nitrogenous compounds in te rre s tria l Antarctic habitats are among the major determining factors in the distribution of macroscopic plants, an assumption based prim arily on the f ir s t fie ld season's observations and subsequent laboratory data on the growth of the isolated organisms (Schofield and Ahmadjian, in press). At the same time, data were gathered on numerous other environmental factors that i t was believed might also be partly responsible for the observed patterns of distribution.

Terrestrial Ecosystems

Climate

Antarctica is situated almost symmetrically athwart the South Pole.

Winds there blow predominantly around the margin of the continent or outward from its center, effectively insulating the continent from the warmer air masses to the north. The high average elevation of the continent (highest of a ll the continents) and the high albedo of the vast, smooth, snow- and ice-covered Polar Plateau causes a ir to descend and to cool near the Pole, and then to flow rapidly northwards toward the periphery. These winds, called "katabatic winds," are among the strongest known anywhere. A consequence of the circular and northerly wind-flow patterns is the fact that temperatures in Antarctica are among the very lowest on Earth. 3

Flora

The Antarctic flora consists almost entirely of cryptogams—

algae, fungi, mosses, a few hepatics, and lichens. There are no trees

or shrubs whatsoever; in fact, there are only two flowering plants in

Antarctica, Deschampsia antarctica and Colobanthus crassifolius, and

these occur only on the northern portions of the Antarctic Peninsula.

The cryptogams are most abundant near the coast of Antarctica. Because there are no trees or shrubs (i.e.., no canopy layer), nearly all of. the cryptogams are subjected to the full rigors of the physical environment; there is no amelioration of the harsh climate by other biotic components. The only conceivable exceptions among macroscopic plants might be some of the inconspicuous crustose lichens that grow among fruticose species, and perhaps a few hepatics.

<

Soils

Most Antarctic soils tend to lack organic matter, especially those in Continental Antarctica (see below), the exceptions being soils in parts of the Antarctic Peninsula and in bird rookeries, where there are accumulations of peat and guano, respectively. In addition, algal peats tend to accumulate in suitable lo ca litie s throughout the ice-free portions of Antarctica. The soils of Antarctica are often very dry, and in several localities (£•£., the so-called "oases") are highly saline. All are underlain by permafrost at depths varying from a few centimeters to no more than 1-1.5 m below the surface. This permafrost effectively inhibits the leaching of ions in the soil column, at least to the degree that leaching occurs in most other regions. The portion of the soil above the permafrost is known as the "active layer." It freezes completely in winter and gradually thaws during spring and

summer, the maximum depth of thaw of a soil being, by d efin itio n , the

active layer. Rocks, vegetation, snow, and ice, as well as the color,

texture, and moisture content of the soil, all influence the depth to

which the soil thaws and the rate at which i t thaws.

Nitrogen Supply

One very important element, nitrogen, enters terrestrial

ecosystems in significant amounts by a very few discrete routes, the

two most important being through fixation of atmospheric molecular

nitrogen by blue-green algae and bacteria and in the excrement of

marine birds that come ashore in spring and summer to nest. The

nitrogen originating in the atmosphere undoubtedly appears in te rre s tria l

ecosystems as ammonia, amino acids, and peptides, while the nitrogen

originating in marine ecosystems appears as uric acid, which is

converted to allan to in, urea, and ammonia by microorganisms. The

quantity of nitrogen is very low in many places; in general, it is

high only in the few areas frequented by birds and in the near proximity

of nitrogen-fixing organisms.

Physical and Biogeography of Antarctica

The Antarctic has been divided into two distinct botanical zones:

(1) Maritime or Oceanic Antarctica (areas between the southern lim it of extensive, closed, i.e .., continuous, phanerogamic vegetation and the southern lim it of extensive and re la tiv e ly rich cryptogamic vegetation), and (2) Continental Antarctica (areas south of the southern lim it of extensive, closed cryptogamic vegetation) (Holdgate, 1969; 1970, Part XII). Available moisture, either from precipitation or in the atmosphere, is undoubtedly the environmental factor that distinguishes Maritime Antarctica from Continental Antarctica. The importance of moisture is shown by the calculations of Orlov (Soviet

Antarctic Expedition, 1966), which are based on radiation balance, latent heat of evaporation, and annual precipitation. McMurdo Station and Oasis Station have, according to his calculations, "radiation indexes of dryness" of 3.0 and 3.1, respectively, values comparable to those of southern Patagonia. By contrast, the subantarctic islands, which are in the Maritime Antarctic Zone, have indexes of only 0.3 to 0.6.

Janetschek (1967) has described many of the characteristics of ( the physical environment that influence the distribution of plants in

Continental Antarctica, and the Russians have attempted a generalized description of its terrestrial vegetation (Soviet Antarctic Expedition,

1966) (Map I ) . Collections of selected species of plants have been plotted on maps by Greene et al_. (1967) and by the Soviet Antarctic

Expedition (1966, Plate 132), while Wise and Gressitt (1965), Follmann

(1963, 1964), and Rudolph (1971) have reported on the southern lim its of plant distributions (Map II).

Continental Antarctica

Continental Antarctica, the botanical zone in which the present study was made, has been subdivided into three subzones: Coastal

Antarctica, the Antarctic Slopes, and the Interior Ice Plateau (Weyant,

1966; Holdgate, 1970, Part X II; Markov et al_., 1970, page 181). --c

•r.

LICHEN-ALGAE

ALGAE-LICHEN

% c MOSS-LICHEN

• d VERTICAL ZONATION

Map I. Botanical regions of Antarctica according to Korotkevich (Soviet Antarctic Expediti00*1966), based on findings of Soviet expeditions and of sources from the literature. n age r fud n otnna Atrtc. aclr lns n mcocpc ug ae ofnd ''1 confined are fungi macroscopic and plants From (1971). Vascular Rudolph Peninsula. Antarctica. Antarctic Continental the to in found are algae and a II. Dsrbto o pat i Mrtm ad otnna Atrtc. ny ihn, mosses, lichens, Only Antarctica. Continental and Maritime in plants of Distribution . I Map I

VASCULAR PLANTS « 90*W OTENOT XET OF: EXTENT SOUTHERNMOST LICHENS LICHENS BRYOPHYTES LA — — ALGAE 80" ‘'’s. i / OS V V ROSS j/ riC ■ A0. +80* Vii’tn i i V * 0 8 + . 0 'A i C SHELF ICE W u ISO1 TO* 0 8 70* 0* 8 70*

Interior Ice Plateau.--The high, central Interior Ice Plateau is the coldest area on Earth. It is characterized by low temperatures, very light snowfall, low cloudiness, and generally light winds. Annual precipitation is for the most part 5 cm (water equivalent) or less; the climate may thus justifiably be characterized as arid (Weyant,

1966).

Antarctic SI opes. —Precipi tation and clouds are more abundant on the surrounding Antarctic Slopes, being intermediate between those of the plateau and those of the coast. The climate of the slopes varies with elevation, latitude, and topographic gradient, both precipitation and temperature increasing rapidly downward along steep slopes. For the most part, however, the climate is severe. Strong katabatic winds, often strengthened by cyclonic activity, and blizzards are common (ibid.). t Coastal Antarctica.--Coastal Antarctica tends to be warmer, cloudier, and more moist than the slopes and the plateau. Cyclonic activity has a strong influence on its climate, as do latitude and surface characteristics ( ib id . ) . The current fie ld study was centered in four localities in the Coastal Antarctic: Cape Crozier, Cape Royds

(both on Ross Island), Kar Plateau, and Miers Valley (both in southern

Victoria Land).

Exposed areas of soil occur along the coast as rocky beaches that are free of snow in summer only, and terrain-shielded areas--the so-called "oases" of East Antarctica (Solopov, 1969). The ice-free valleys of southern Victoria Land (Pewe, 1960; Gunn and Warren, 1962)

(Map I I I ) and the Bunger H ills of Wilkes Land (Apfel, 1948; Shumskiy,

1957) are probably the best known "oases." While the flo ra of the 9

Map I I I . The "McMurdo Oasis" of southern Victoria Land. Quadrat IV was established in the southern part of the "oasis" near Miers Valley, which is situated near the lower right-hand corner of the map. Kar Plateau is situated in the upper right portion of the map. Redrawn from Gunn and Warren (1962). r— 1 6 0 °0 0 'E 162“ 0 0 'E 164° OO'E *»76°30' S ■4" t. Endeavoi/r

Allan < 7 CL. Nunatak/i Evans^Cape Ross ledmo $ ^/rjGljcier; J0

Cape Archer a Carapace KAR PLATEAU Nunatak 'rantte Harbor

Cape Roberts

-O lb Dunlop * * 0%c,ilsland f ^ 4 McMurdo ovav^JSCv.; \ gnejss p0int o ^ , . ^Marble 7 7 ° 3 0 'S -Lsi<^4p^/1157”

& r m k : Butter owe~oint Piedmont acier

— 7 8 “ 0 0 'S

MIER

Arid Zone (negative "accumulation" below 1000 meters):

Bare Rock: 11

Bunger Hills is the richer because of its lower latitude, the two

"oases" appear otherwise to have very sim ilar general characteristics

(G. A. Llano, personal communication, 1971; Shumskiy, 1957; Kuprevich

et aJL, 1959; Vialow and Sdobnikova, 1961; Markov et al_., 1970; Gunn

and Warren, 1962; Nichols, 1963; McCraw, 1967; Kohn et al_., 1971).

The area of the "McMurdo Oasis" is about 2500 km^, while that of the

"Bunger Oasis" is on the order of 450 km^.

Life Arenas

Soviet investigators have attempted to establish the existence of "life arenas," concentric biotic zones distinguished by the numbers of species and populations they support, both of which parameters decrease inward from the coast towards the in terio r of the continent

(Gollerbakh and Syroechkovskii, 1958; Markov et al_., 1970). They have distinguished a Subantarctic Belt and an Antarctic Belt, the latter consisting of (1) a Northern Marginal Zone that is roughly coincident with Coastal Antarctica and the Antarctic Slopes and (2) an In terio r

Southern Zone roughtly equivalent to Weyant's In terio r Ice Plateau.

Janetschek (1967, Figure 2D) and Claridge et al_. (1971) presented data that support the concept of such concentric biotic zones.

Northern Marginal Zone.--The Northern Marginal Zone, which is several hundred kilometers wide, has no true land birds, only two species of penguin among the breeding birds (with rare exceptions), and no flowering plants. A limited number of moss and lichen species occupy small, widely scattered areas. The southern boundary of the Marginal

Zone was set to coincide with the southerly limits of mosses and of the nesting grounds of such birds as the Snow Petrel and the South Polar

Skua.

In terio r Southern Zone. —There are no animals or mosses in the

In terio r Southern Zone; microorganisms do occur there, however. The macroscopic flo ra consists of a few species of lichens, which occupy

only negligible areas of rock.

From, north to south, plants (excluding bacteria) tend to disappear

in the following sequence: macroscopic fungi, vascular plants, hepatics, macroscopic algae, mosses, and lichens (Map I I ) . While this statement is a simplification of reality and does not apply to every situation, it is none the less a useful and justifiable generalization.

The horizontal (i_..e, latitudinal) and vertical (i...e., altitudinal) zonation of plants in Antarctica, of which Soviet investigators have made so much, probably reflects, not only gradients in the climatic factors described by Weyant (1966), but gradients in geographic and biological factors as well. Gradients in temperature and moisture, angle of incident solar radiation, distance from the coast, and the availability of suitable nitrogen compounds are probably the most important causes of zonation. DESCRIPTION OF FIELD AND LABORATORY STUDIES

Experimental Laboratory Studies

The research undertaken in Antarctica during the second (1967-1968)

and th ird (1968-1969) fie ld seasons was organized to test the hypothesis

that nitrogen compounds in the environment play an important role in

determining the distribution of plants in Antarctica. This hypothesis was suggested by the results of field observations and laboratory work

carried out during the first (1963-1964) portion of the study. The

experimental laboratory v/ork was performed with two isolated lichen fungi, the sheet-like green alga Prasiola crispa, and the moss Bryum algens. The lichen fungi and the moss were isolated into axenic culture;

< the alga was obtained in unialgal, but not axenic, culture. A number of nutritional studies were performed with the isolates.

Lichen Fungi

Introduction.—Because it is usually difficult or even impossible to maintain intact lichen thalli in the laboratory for long periods of time, and because i t is d iffic u lt to measure the responses of intact thalli to specific compounds, especially organic compounds, it is often more convenient to isolate the symbionts of lichens into axenic culture.

In doing so, the mycobiont (the fungal partner) is separated and grown independently of the phycobiont (the algal partner). While there is no way to judge whether the results obtained in v itro with separated

13 14

symbionts are applicable to lichens growing in their natural habitats,

it is probably safe to assume that at least some of the findings

obtained in the laboratory can be extrapolated to field conditions.

Isolation Procedures.--During the Antarctic summer of 1963-64,

approximately 200 single-spore isolates of lichens from Victoria Land

(the Cape H a lle tt, McMurdo Sound, and ice-free valley areas), Ross

Island (primarily Hut Point Peninsula and Capes Royds and Crozier),

and scattered other regions of the continent were obtained on various

media by the isolation methods described by Ahmadjian (1961). These

200 successful isolates were less than 10 per cent of the 2,500

isolations attempted.

Standard microbiological media, modified to provide different

pH values, vitamins (biotin, thiamine, and pyridoxine), and other con­

stituents (glucose, asparagine, and yeast extract), were employed for

initial growth of the isolates. There was no discernible correlation between successful germination or subsequent colony growth and cultural conditions, data of collection, or species. For example, ascospores from one collection of a species might yield a very high or very low percentage of germination, while ascospores from another collection of the same species from a d ifferen t area might behave to the contrary.

Experimental Organisms. —Two mycobionts were selected for studies of temperature and pH optima and nitrogen nutrition. One isolate, from the Jones Mountains, Eights Coast, West Antarctica, was selected from among the isolates of one of the mycobionts ("Lichen A"), while the other, from Ross Island, East Antarctica, had been in culture for approximately eight years (Ahmadjian, 1958; 1961) ("Lichen B").

Lichen A mycobiont was isolated from Lecanora tephroeceta Hue, and

Lichen B mycobiont from Leeidea sp. These two isolates were chosen

because they had been in culture for different lengths of time (less

than one year versus eight years, respectively) and because they grew rapidly enough to produce measurable mycelium biomass within a reasonable time.

Lichen A mycobiont was 7 mm in diameter a fte r nine months in a screw-cap culture tube on a modified solid malt extract—yeast extract medium (MYEM): malt extract, 20 g/1; yeast extract, 2 g/1; pyridoxine,

200 mg/1; in o s ito l, 10 mg/1; thiamine, 200 mg/1; b iotin, 5 mg/1; agar,

20 g/1; pH 6 . 8 , adjusted with 0.1 ^ NaOH. Growth of the other isolates of this species from the same collection s ite was sim ilar on a ll four of the isolation media used (Sabouraud's Dextrose Agar, Nutrient Agar,

Corn Meal Agar, and MYEM). The v ia b ility of the ascospores of

L_. tephroeceta, based upon a total of twenty spores obtained from the same specimen, was approximately 90 per cent. (Hue (1915) states that this is a very fertile species, its thallus soon disappearing under the quantity of apothecia) The isolates, all of them derived from single asospores, were o rig in ally pink; with age, the cultures turned yellow.

All known collections of L tephroeceta are described in Table 1.

Lichen B (Isolate 11 in Ahmadjian, 1961) was collected from the ground on Ross Island in 1957. The mycobiont—a monospore isolate— developed very slowly at firs t; after nine to twelve months' growth at

8 C, it was only 1 to 2 mm in diameter. After several years in culture, TABLE 1

HABITAT DATA FOR ALL AVAILABLE COLLECTIONS OF Lecanora tephroeceta Hue FROM WEST ANTARCTICA

Herbarium, or Locality and Literature C ollection Date o f Inform ation from - Type o f Coordinates Speclmen(s) C ita tio n Substrate Collector(s) Data ■ C ollectio n Other Sources Remarks Habitat

EIGHTS COAST:

Jones Moun­ tain s

—Intrusive Schofield DODGE (B url­ Moss K. P. Rennell ------. 6 I I 64 Thousands o f Snow Located 100 km Guanotrophic Spur (73° AA-122 and ington) Petrels nest op . from coast. 30'S, 94" AA-129 Intrusive Spur'5' Mycobiont from 25'W), AA-129 used in 730 m.s^.m. nitrogen experi­ ments .

ELLSWORTH MOUNTAINS:

Heritage Range

—Welcome Schofield D itto In cracks K. P. Rennell —— 26 X 1 6 3 Isolated nunatak Very small s p e d - ?Non-guano- Nunatak AA-87 and 700 km from coast. men. Associated trophic (•The Pimple') AA-107 Apparently no bird- species'5' are (79-06'S, 85® life , only very known to 'p re fe r1 54"/.'), 14.4 km i nfreguent, pass i ng orni thocoprophi t i c S o f Camp skuas'5* b' locations. Gould

SOUTH SHETLAND ISLANDS:

Deception Follmann U Moss G. Follmann ------1963 At le a st 4 penguin Guanotrophic Island (62° 13852 rookeries on 55'S, 60* Redon 45 H is la n d ' J. Numerous Redon 45: Over­ 38'W) bird s fly in g and grown by a bias- walking over inner teniaceous lichen > and outer shores'e'. as indicator of The nitrophilic nitrogenous con- plant association, ditions. Ramalinctum tere- bratae, and Pras- iola crisna occur(f.g).

—Pendulum Gain 76 Hue (1915) 'cendres L. Gain A t 20 m.s_.m. 25 X II 08 Abundant b ir d lif e Type lo c a lity . Guanotrophic Cove (62° (TYPE) pp. 89-90 agglom- near,Pendulum 55'S, 60° erees* Cove''. Associ­ 33'W) ated v/ith Lecanora (Caloplaca) cine'rf- cola Hue(n). TABLE 1.--Continued

Herbarium, or Locality end Literature Collection Date o f Inform ation from Type of Coordinates Specimen(s) C ita tio n Substrate C o lle cto r(s) Data C ollection Other Sources Remarks H abitat

Robert Redon 8 and 9 DODGE (B u rl- 'sobre J . Redon I 66 Penguin rookeries Spermogonia on ly. Very probably Island (62° ington) rocas' a t Coppermine no apothecia. guanotrophic 24'S, 59° P oint’ s ). Ringed Precise lo ca tio n (c f. Redon, 34‘ W) Penguin rookery o f c o lle c tio n 15S9). (exact location not stated. on island nQt specified)lr ). Giant Petrel and A nta rctic Tern nest'*)- R,. terebratae associ­ ation present(f).

MELCHIOR ARCHIPELAGO:

Gr.ega Island (64‘ 20'S, 62''56'W!

—northeast S ipie 384 Dodge, Lichen P. A. S iple T i l l 40 Ringed Penguin Numerous indica- Guanotrophic Landing Flora of Ant­ rookery found at tions of nitro­ arctica (un­ ‘Melchior Harbor.' genous conditions published Many Blue-Eyed Shag in a small (ca_ 30 manuscript) observed, probably km‘ ) area. •nest therelm .n). Siple made at least 6 c o lle ctio n s o f P. c r is n a nearby in

—Chair, S iple, D itto P. A. S iple, ? I I I 40 Point F razier, R. G. Frazier, and Bailey and D. K. 364c - m Bailey

—Water S iple and P. A. S iple T i l l 40 Landing Richardson and H. H. 333 Richardson

Lambda Is ­ See information for Remarks for Cmega Guanotrophic land (64c Omega Island. Island apply to 18‘ S, 63° OO’W) Lambda Island.

—northeast S iple 380- Pale P. A. S iple T i l l 40 Landing g-20 granite TABLE 1 . - Continued

Herbarium, or L o c a lity and L ite ra tu re C ollection Date o f Information fo r Type o f Coordinates Specimen(s) C ita tio n Substrate C o lle cto r(s) Data C ollectio n Other Sources Remarks H abitat

ARGENTINE ISLANDS

Uruguay Island

—B ritis h Tyler L-2- DODGE (Burl- Rock protrud- 0, Tyler . Exposed to 8 IV 59 'Abundant animal and Young specimen, Probably F oxtrot Base 4(a) ington) ing from snow ' sun most o f bird life , and water, guanotrophic {63’ 14'S, and ice. time are found in th is 64°14‘ W) group (j_.e., the Argentine Islands)'"1. , . South Polar Skua and Blue-Eyed Shag occur(o).

ADELAIDE Follmann Dodge..Lichen Decaying G. Follmann' At coast 71963 Abundant b ir d life on Immature speci­ Probably ISLAND 14173 Flora of Ant­ wood. nearby Avian Is - ■ men. Island is guanotrophic (67’ 46'S, a rc tic a (un­ land'P). £. crisca large (ca. 115 x E6i S4'W) published common in 7egion(h). 40 km);Towever, manuscript) I n it ia l phase o f R. wood substrate terebratae. with may have come Mastodia tesselata from buildings (=lichenized P. on S end o f is ­ crispa) as domi­ land, only ca. nant species(f). 400 m from Avian Island.

DE5ENHAK Bryant 26 D itto Rock H. M. Bryant A t 24 m.s_.m. 7XII 40 South Polar Skua Group of small Guanotrophic ISLANDS nests on islands, islands in and A ntarctic Tern close proximity ('Dcbenham probably nests Is la n d ') there'R"*). Numer­ (68 •OB'S, ous c o lle ctio n s o f 67‘ 05'W) P. crispa from Kargueyitie Bay region'SJ

(a) J. F. S plettstoesscr, personal communication. ( d) D. A. Coates, personal communication. (c) 'Blasteniaceous1 the 11 us (Blastenia so.), two collections; Buellia latemarginata Darb. (=3. actinobola (Hue) Darb., fide Lamb (1968)) (Schofield AA-108a, Heritage Range, 16 I 64, leg. K. P. Rennell): 'I have found B. latemaroinaia to be a highly nitrophilous species ... it occurs preferentially high u? or even on the zenith o f bard rocks . . . (and is ) . . . often associated w itn other c h a ra c te ris tic a lly n itrophilo us species such as Xanthoria eleeans. X. Candelaria. Rinodina Petermanni, and Hastodia t esselata (the lichenized form o f Prasiola c ris p a ) 1 (Lamb, 1968, pp. 52-53 (c f . Table XXV. pp. 116-120, also)). Tne occurrence together of L. tephroeceta (two collections), B, latemarginata, and Blastenia so. on Welcome Nunatak strongly suggests that nitro­ genous conditions exist there despite the great distance from the coast. A source of amnonium of any kind would also explain these collections, and this is probably the most plausible explanation. (d) Chart HD 6796 (U. S. Hydrographic Office). (e) R. E. Cameron, personal cocmunication (25 IV 69). ( f ) Follmann (1965). (g) United States National Museum, Herbarium of Cryptogamic Botany, Smithsonian Institution, Washington, D.C.; and Herbarium of Cryptogamic Plants, Field Museum of Natural History, Chicago. TA3LE 1.—Continued

(h) Hue (1915), pp. 89-90 and 194. (i) U. S. Hydrographic Office (1960). ( j ) K. R. E verett, Personal communication. (kj Saiz and Hajek (1968). (mj Eklund (1945). (n) Friedmann (1945). (c) Burton (1970). (pi United States Board on Geographic Names (1956). (q) Bryant (1945), Figures 3 and 4.

i 20

its growth rate increased and was relatively rapid at 18 C. Initially,

the colonies were white; later they became partly yellow and then

turned lig h t brown.

Nitrogen Studies.--Lichen A was used in the studies of nitrogen-

source preference. Thirty-eight nitrogen sources were supplied

separately, at concentrations of 0.035 g/1 (ammonium and nitrate salts)

or 0.018 g /1 (amino, amide, purine, pyrimidine, riboside, ureide, and

miscellaneous compounds, including peptides, peptone, and casein hydro­

lysate) to 0.2 to 0.3 mg of washed, homogenized mycelium taken from

cultures grown in Lilly and Barnett Synthetic Medium plus biotin (5 mg/1)

and thiamine (100 mg/1) (Ahmadjian, 1967, p. 21) for three weeks at

15 C and then stored in polyethylene bottles for one month at 5 C in

a few m illiliters of nitrogen-free medium.

Molybdenum should have been added to the media because reduction

of nitrate requires trace quantities of the element. I t was not supplied.

However, i t has been shown many times (je.£., Nicholas, 1952; see also

Foster, 1940, p. 251) that water, reagents, and other materials contain sufficient quantities of molybdenum to support the growth even of such

rapidly growing fungi as Aspergillus and PeniciIlium. Molybdenum can be eliminated from media only by painstaking procedures. Because lichen fungi (especially Antarctic lichen fungi) grow hundreds or thousands of times more slowly than Aspergillus and PeniciH i urn, and because the constituents of the media were not treated to remove contaminating molybdenum, i t can be assumed that there was sufficient molybdenum for potential enzymatic reduction of n itrate by L tephroeceta. 21

The experimental media were sterilized with Millipore (0.45-nm

pore size)J Morton ultrafine sintered-glass, or Seitz filters, and

were dispensed in 45-ml aliquots to cotton-stoppered 125-ml erlenmeyer

flasks that had been cleaned with sodium dichromate-sulfuric acid

solution. The medium was buffered with 10 ml of M/15 Na, K phosphate

buffer (pH 5.15) per flask. The water was Pyrex distilled..

Inoculum (0.2 mg of macerated mycelial fragments suspended in

5 ml of distilled water, according to 50 dry-weight determinations) was added to each flask with a sterile Cornwall syringe pipette, bringing the volume of solution in each flask to 60 ml. The frequency distribution of inoculum dry weights is plotted in Graph I . The pH of the medium plus buffer was 5.3 in all except six cases, whose pH values fell between 5.1 and 5.6. The result was a pH range among a ll of the media of only 0.5.

The inoculated flasks were incubated at 20 C. They were not shaken. Mycelial dry weights of a t least four flasks were determined for each nitrogen source a fte r 21, 78, and 99 days. A ll of the mycelium from each flask was rinsed on filte r paper with distilled water, dried overnight on the filte r paper at 60 to 70 C, and weighed to the nearest tenth milligram.

A smaller-pore f i l t e r should have been employed to ensure complete sterilization. Nevertheless, there was no pattern of con­ tamination that could be attributed to use of the larger-pore filte r. The solutions containing aspartic and glutamic acids were s te rilize d with Millipore filters; all other solutions were sterilized with either Morton or Seitz filters. 22

a crv § =>6 3o g 2 5 o Cl o0)

Weight of Inoculum, mg

Graph I. Distribution of inoculum weights in the nitrogen- source experiment with the mycobiont Lecanora tephroeceta Hue. A total of 49 dry-weight determinations was made. 23

Temperature Studies.--Two experiments were performed to determine

the optimal temperatures for growth of the mycobionts of Lichens A and B.

In the f ir s t of these experiments, the incubation temperatures were 3,

7, 11, 15 and 19 C. Dry weights of mycelium were determined a fter nine

and eighteen weeks of growth in a medium consisting of 20 g/1 of malt

extract (Difco), 2 g/1 of yeast extract (Difco), 5 mg/1 of biotin, and

100 mg/1 of thiamine, and made to volume with d is tille d water. The

in itia l pH was approximately 6.3. The mycelia were incubated in 125-ml erlenmeyer flasks containing 25 ml of medium and 2 ml of inoculum. The in itia l dry weight of the inoculum of Lichen A was 1.42 mg per fla s k, while that of Lichen B was 0.08 mg.

In the second temperature experiment, which involved only Lichen A, the incubation temperatures were -1 , +4, +9, +14, +19, and +24 C. The medium consisted of 5 g/1 of glucose (D ifco), 2.5 g/1 of peptone (D ifco),

1.0 g/1 of malt-extract broth (Difco), and 2.5 g/1 of casein hydrolysate

(Nutritional Biochemicals). The initial pH was 6.4. The final pH was not determined. Each of the 125-ml erlenmeyer flasks used in this experiment contained 50 ml of filte r -s te r iliz e d medium plus 4 ml of inoculum. Inoculum dry weight was 0.4 mg.

Hydrogen Ion Concentration. —The influence of pH on both mycobionts was determined by sim ilar techniques, more thoroughly on L.. tephroeceta than on Lecidea sp. The la tte r mycobiont (Lichen B) was grown in liquid Lilly and Barnett Synthetic Medium adjusted to and buffered at at number of pH values betwen 4.0 and 8.0. The inoculum, which had been grown at 15 C in liquid medium of pH 6.5 for fourteen weeks, was prepared 24 by suspending the combined yields from ten flasks (about 340 mg) in

100 ml of s te rile d is tille d v/ater plus buffer ( 1 :2) , homogenizing i t in a Waring blender for 1 min, and pipetting the resulting suspension in 10-ml aliquots to nine erlenmeyer flasks, each containing 250 ml of Teorell's Universal Buffer (Cavanaugh, 1956) prepared to yield a different pH. Each buffered mycelial suspension contained between

0.15 and 0.17 mg of mycelium per m illilit e r , as shown by three dry- weight determinations each.

The experimental media were prepared in two distinct steps: f ir s t , a lOX-strength glucose and asparagine solution was s te rilize d by filtration, and a minerals solution, plus each of nine buffer solutions, were autoclaved; second, the resulting sterile solutions, plus the nine buffered fungal inocula> were combined in s te rile 125-ml erlenmeyer flasks, giving fin al concentrations equivalent for each constituent to those in L illy and Barnett Medium (biotin and thiamine were not added), and an inoculum of 0.95 mg per flask. The result was nine series of vitamin-free Lilly and Barnett Medium, 25 ml per flask, plus macerated fungal mycelium.

The pH values of some of the buffer solutions changed after inoculation. The intended values and the actual values (in parentheses) were as follows: 4.0 (4.0); 5.0 (5.0); 5.5 (5.4 to 5.5); 6.0 (6.0);

6.5 (6.5); 7.0 (7.0); 7.5 (7.3); 8.0 (7.6); and 9.0 (7.9 to 8.1). The incubation temperature was 20 C. The results are plotted as the means of mycelial dry weight for three to five flasks in Graph II. Graph III shows a typical growth curve for this experiment. 25

o i CD

i m o Q

I I f t -I I ! I I 1------O CO 10 M" CM . O (Buj) 1 H 9 I 3 M AcJd

Graph I I . Growth of the mycobiont Lecidea sp (Ahmadjian #32) in liquid medium at various pH values. Triangles indicate growth at 24 days, circles growth at 49 days, squares growth at 74 days, and crosses growth at 99 days. 26

Graph I I I . A typical growth curve for the mycobiont Leeidea sp. (Ahmadjian #32) at pH 5.0. The vertical lines give the range of dry weights at each weighing. The figures to the right of the points give the pH of the medium at each weighing. The greatest range in values occurred at 74 days. This may re flect the onset of autolysis or it may be due to the shift from a logarithmic growth rate to a negligible or stationary growth rate, some colonies in the flasks being at the end of the former and some at the beginning of the la tte r . The dry-weight values for the three other time periods are remarkably close. The mycelium in five flasks were weighed for each determina­ tion. Points are the average dry weight of mycelium per flask. 10

8

£ 4.8 6 (£ UJ 4.8 4 >* CC a 5.0

2

0 0 25 50 75 100 TIM E (days)

^sjf\5 The mycobiont of U tephroeceta (Lichen A) was grown at twelve pH values between 4.0 and 8.4 in 50 ml of the following liquid medium:

2.5 g/1 of glucose; 2.5 g/1 of malt-extract broth; 1 g/1 of yeast extract and 2.5 g/1 of casein hydrolysate. The pH of the medium, which was approximately 6.4 at firs t, was adjusted with either 1 NaOH or 1 ji

HC1. The incubation temperature was 20 C. The inoculum dry weight was 0.2 (±0. 1) mg per flask.

Mycelium grown at 14 to 15 C for two months in the above liquid medium at a pH of about 6.4 was harvested, washed twice with 700 ml of sterile distilled water, macerated in a Waring blender for 1 min, and dispensed in 5-ml aliquots of 125-ml erlenmeyer flasks with a Cornwall syringe pipette. The dry weights determined a fter twenty-one days are tabulated in Table 2. <

Results of Nitrogen-Source U tiliz a tio n . —The growth of Lichen A on the th irty -e ig h t nitrogen compounds is presented in Table 3.

The table shows that the control flasks contained 4.2 mg dry weight of mycelium a fte r seventy-two days, but less than 1 mg after ninety-eight days, an indication that autolysis took place when the carry-over nitrogen was depleted. The growth curves are plotted in Graph IV.

Ammonium-nitrogen compounds supported the most growth. Dry weights of about 16 to 18 mg per flask were obtained a fte r seventy-eight days, and 17 to 23 mg after ninety-eight days; thus, the mycelium was s t i l l in the growth phase at ninety-eight days in the presence of ammonium. 29

TABLE 2

GROWTH OF LICHEN "A" MYCOBIONT (Lecanora tephroeceta) AT TWELVE pH VALUES BETWEEN pH 4.0 AND pH 8.4

Growth a fter 21 days at 20 C in 125-ml erlenmeyer flasks.

Final pH Dry Weight In itia l pH (58 days) (21 days), mg(a'

4.00 4.09 2. 8 (b*

4.20 4.14 2.7

5.24 5.20 1.3

5.70 5.89 1.0

6.12 6.29 0.9

6.43 6.56 1.1

7.00 6.95 1.3

7.30 7.20 0.7

7.45 7.44 0.8

7.90 7.79 0.8

8.20 8.12 0.6

8.40 8.32 1.0

(a) Dry-weight values are the means of five replicate flasks.

(b) The same value was obtained at IO C. TABLE 3

GROWTH ATTAINED BY THE MYCOBIONT Lecanora tephroeceta Hue ON VARIOUS SOURCES OF NITROGEN IN BUFFERED MEDIUM

Unless indicated otherwise, the L stereoisomer of the amino acid was used.

Dry-Weight Yield, mg In itia l Nitrogen Source^ pH at Change in pH At 21 Days At 78 Days At 98 Days pH(fa) 78 Days(c) a fter 78 Days(d)

Glutamine 3.2 23.9 24.9 5.2 - 0.1 Urea 2.1 18.4 22.3 5.8 +0.5 Ammonium tartra te 2.8 17.6 19.5 5.2 - 0.1 NH4CI 2.5 17.5 18.0 5.1 - 0.1 (N fU 2S04 2.3 16.6 23.0 5.2 - 0.1 Proline 2.6 16.4 14.2 5.4 Alanine 3.1 16.2 — 5.4 +0.1 nh4no3 2.9 15.9 16.8 5.1 - 0.2 Xanthine — 15.3 12.9 Not taken 5.6 7 Leucine 3.6 15.1 — Asparagine 3.3 14.3 14.7 5.2 - 0.1 Uric acid 3.3 13.2 — 5.6 5.6

Casein hydrolysate 2.3 8.2 5.4 Arginine 2.8 7.3 3.6 KNO3 2.7 7.2 5.7 Glutamic acid 3.3 7.1 — 5.1 5.1 Ca(N03)2 3.0 6.6 6.9 Seri ne 3.1 6.2 4.8 Methionine 2.4 5.9 — Cysteine 3.0 5.8 3.1 5.1 5.1 CO 0 TABLE 3 . —Continued

Dry-Weiqht Yield, mq Nitrogen Source^3) Change in pH a fter 78 Days^wAt 21 Days At 78 Days At 98 Days 78 Days(c'pH a fter 78 Days^wAt

Cystine 3.5 5.6 • 3.4 Tryptophane 3.1 5.5 2.4 Allantoin 2.3 5.3 — 5.5 5.3 - 0.2 Adenosine 3.5 5.2 — Phenylalaine (DL) 2.5 5.1 2.2 Thymidine 2.8 5.0 2.1 Cy ti di ne 2.3 4.8 — Histidine 3.7 4.7 2.1 ' Aspartic acid 2.1 4.6 3.0 5.1 5.1 Glutathione (DL) 2.4 4.6 — 5.2 - 0.1 Thymi ne 3.0 4.6 2.6 Peptone 2.5 4.4 — 5.4 Adenine 2.5 4.3 2.6 5.1 5.1 CONTROL 2.2 4.3 0.8 Tyrosine 3.1 4.0 2.7 Uracil 2.1 3.8 2.8 Uridine 2.2 3.7 2.7 NaN03 1.8 3.0 0.8 Threonine 2.7 2.3 2.1

(^Listed in descending order of dry-weight yield of fungal mycelium at 78 days, (b)Initial pH = 5.3-5.4 except where indicated otherwise. (c^pH at 78 days was 5.3 except where indicated otherwise. (^Where no value is given, the change in pH was less than 0.1. 32

Graph IV. Growth of the mycobiont Lecanora tephroeceta Hue on 38 nitrogen sources, arranged according to class of nitrogen compound, (a .) Growth on nitrate and ammonium salts, (b .) Growth on dicarboxylic amino acids and their amides, (c .) Growth on aromatic and heterocyclic amino acids, (d .) Growth on amino acids with nonpolar sidechains. (e.) Growth on other amino acids. (f.) Growth on ribosides, (g.) Growth on purines and pyrimidines, (h .) Growth on ureides. ( i . ) Growth on miscellaneous nitrogen sources. DRY WEIGHT (mg) 25 20 25 25 0 10 0 10 0 RMTC N HTRCCI AIO ACIDS AMINO HETEROCYCLIC AND AROMATIC IABXLC MN AIS N TER AMIDE: THEIR AND ACIDS AMINO DICARBOXYLIC IRT AD MOIM SALTS AMMONIUM AND NITRATE 10 20 20 20 30 040 30 30 0 4 ME (DAYS) E IM T 40 50 50 50 60 60 ‘Tryptophane 60 CONTROL' I I CONTROL' oina' a iin ro v T 70 70 080 70 ltmc acid Glutamic 80 080 80 CONTROL 90 Co (NO,). KNO DO 100 100 DRY WEIGHT (mg) 20 25 25 20 25 0 10 0 ICLAEU NTOE SOURCES NITROGEN MISCELLANEOUS PYRIMIDINES AND PURINES 10 20 20 20 30 30 30 0 4 0 4 0 4 ME (DAYS) E IM T 50 50 50 60 60 60 yoie • Cytosine l toin ftto llo A CONTROL r ii c ira 70 08 90 80 70 080 70 o«n _hydroly»o>«Co»«ln 80 90 90 100 100 100 34

Nitrate-nitrogen compounds supported much less growth than ammonium-nitrogen compounds. Of the three nitrate compounds (not including NH^NO^, maximum growth occurred with KN 03 at seventy-eight days and with CaCNO^ at ninety-eight days. Between the seventy- eight- and ninety-eight-day readings, the mycelium in KNOg had decreased nearly 2 mg, which suggests that autolysis had set in. Sodium n itra te inhibited growth in comparison to the control medium. This result may be related to the well-known and widespread biological process of active transport of sodium ions out of cells of many organisms; the potassium ions in the flasks with KNOg, on the other hand, may have been actively accumulated. It' is possible that the fate of the accompanying cation influenced the rate at which n itrate was absorbed.

The pH values of the filte re d medium obtained from the combined c flasks of each nitrogen.source are presented on the right side of

Table 3. In spite of the high concentration of buffer and the small amounts of fungal growth, there were measurable and consistent drops of

0.1 to 0.2 units in the pH of the four media containing ammonium salts because NHg molecules were removed from solution. In the control and nitrate media, there was no measurable change in pH. Significant uptake of nitrate would have raised the pH.

The mycobiont grew very well in the medium with urea, being higher after seventy-eight days of growth than in all of the other media except that containing glutamine. At ninety-eight days, growth on urea was exceeded only by that on glutamine and ammonium sulfate. 35

The change in pH of +0.5 in the urea flasks was probably due to the hydrolysis of urea by extracellular fungal urease, which would have led to the production of ammonia and consequently to a rise in pH.

This change in pH was significantly greater than that of any of the other thirty-seven sources of nitrogen.

A standard microbiological test was carried out with the mycobiont of Lichen A to detect the production of urease. The test, which employs

Difco Urea Agar, was performed at 19 C. Within 18 hr of inoculation with the mycobiont, ammonia released by hydrolysis of the urea in the medium had produced a discernible change in the color of the medium due to the higher pH. Similar results were obtained with nearly all of the other lichen fungi tested for production of urease, including the mycobiont of

Buellia frigida Darb., a saxicolous Antarctic species. I t is concluded, therefore, that the urea in the experimental medium was hydrolyzed to ammonia and carbon dioxide by extracellular urease before the nitrogen was absorbed by the fungus.

Of the riboside, purine, and pyrimidine nitrogen compounds employed, the fungus utilized only xanthine and uric acid to any extent. Allantoin, the oxidation product of uric acid, which is converted by some organisms to urea and glyoxylate, was not utilized. These results suggest that uric acid and xanthine were absorbed as intact molecules rather than as ammonia produced, via allantoin and urea, from them. The fungus Candida util is absorbs uric acid and xanthine by two specific carrier systems

(Quetsch and Danforth, 1964); such a mechanism may account for the selective utilization by L. tephroeceta of uric acid and xanthine and 36 for its nonutilization of such related substances as allantoin and adenine. This interpretation assumes, of course, that the growth rates of the fungus on the various nitrogenous compounds re fle ct both the permeability of the fungus to the compounds and the enzyme complement of the organism, but i t would be impossible to distinguish the influence of one from the other with the present data.

Discussion. The differences between the dry-weight yields obtained with glutamic acid and aspartic acid and those obtained with their amides, glutamine and asparagine, are striking. Glutamine supported by far the greatest amount of growth of all thirty-eight nitrogen compounds used—six times that obtained with the control medium and more than three times that obtained with glutamic acid. The same 3:1 ratio also held between asparagine and aspartic acid. There was a drop in pH of

0.1 with glutamine and asparagine at seventy-eight days, but there was no change with either glutamic acid or aspartic acid. Though they are far from conclusive, these results suggest that glutamine and asparagine were deamidated enzymatically in the medium by extracellular fungal enzymes and that the resulting ammonia was absorbed, causing a drop in the pH.

Moiseeva (1961) showed that the intact thalli of nearly all of the forty-one species of lichens she tested, including two Antarctic species, produced extracellular asparaginase and urease. On the other hand, Smith (1960) concluded from his own studies on discs cut from intact th a lli of Peltigera polydactyl a that asparagine was taken up from solution as the whole molecule, or else was absorbed and only 37 very slowly deamidated. Thus, the mechanism by which glutamine and asparagine were utilized by L. tephroeceta is open to question. The tentative conclusion is offered that they were first deamidated by the mycobiont, and that the resulting ammonia was absorbed from solution.

Fourteen amino acids were used, but only three of them (proline, alanine, and leucine) supported significantly greater growth than the control medium. These three amino acids have in common nonpolar sidechains; this characteristic may have resulted in more rapid absorption of these amino acids than of the less lipid-soluble amino acids. The only other amino acid with a nonpolar sidechain was phenylalanine. Since phenylalanine and the two other amino acids with aromatic constituents (tyrosine and tryptophane) were not used by the fungus, it is inferred that amino acids with aromatic constituents are unsuitable sources of nitrogren for L. tephroeceta.

Some organisms (

Such a system conceivably could exist in U tephroeceta. The possibly greater solubilities of such amino acids in the cell membrane, or their lower net electrostatic charge (at least on their sidechains) may also have enhanced their absorption by the mycobiont.

Glutathione and peptone supported about the same amount of growth as the control medium, and casein hydrolysate supported only about twice as much growth as the control. The results obtained with these three nitrogen sources indicate ( 1 ) that peptides are not utilized by 38 J-. tephroeceta (j_.e,., that there are no extracellular enzymes to hydro­ lyze peptides to their constituent amino acids), and ( 2) that very few amino acids are u tilz ie d , either because they cannot be absorbed or because there are no enzymes inside the cells for converting them to other, essential amino acids.

Chart I summarizes in diagrammatic form the results and conclusions of the nitrogen-source studies with JL. tephroeceta. The compounds are arranged in groups roughly according to th eir biochemical relationships.

The arrows indicate the possible reaction pathways for the compounds supplied, and the routes by way of which the compounds may have entered the fungal c e lls . Compounds or classes of compounds that supported l i t t l e or no growth in the study have no arrows. The scheme presented in Chart I appears to be an in ternally consistent and ecologically t meaningful explanation of the experimental results.

On the basis of the results and inferences, it is suggested that nitrogen compounds are utilized by L. tephroeceta in either of two ways: ( 1) they may be u tilize d as ammonia or ( 2) they may be absorbed in tact. In the fir s t case, the compounds are converted extracellulary to yield ammonia, either by hydrolysis, as in the case of urea, or by deamidation, as in the cases of asparagine and glutamine. In the other case, the compounds would include proline, alanine, leucine, uric acid, and xanthine.

If these inferences are correct, the mycobiont of U tephroeceta, and possibly of other Antarctic lichens found in similar guanotrophic habitats, displays selectivity in utilizing available nitrogen sources: RIBOSIDES

PYRIMIDINES PURINES ADENINE GUANINE URIC ACIO UREIDES PEPTIDES ALLANTOIN . CASEIN HYDROLYSATE XANTHINE PEPTONE REA GLUTATHIONE

DICARBOXYLIC AMINO ACIDS ASPARTIC AC1Q GUUTAUIC *C iO INORGANIC SALTS ThC»P AM'PCS- ASPAPAi'^t NITRATES CLUTAU1MC AMMONIUM SALTS AMINO ACIDS WITH NONPOLAR AMMONIUM AMINO ACIDS' SIDE CHAINS P*CU«*&I c'JHMATeO ort A L A N ^ V AdSORQ£0 tftU C T f LEUCiNEl AMiNO ACIDS WITH AROMATIC RINGS, PY.ENYC*L*hWe :ABSORPTION T tftO S'N E TKYPTOPHAME i OTHER AMINO ACIDS _SL. ASSIMILATION

Chart I. Suggested pathways by which the 38 nitrogen sources were absorbed and assimilated by the mycobiont Lecanora tephroeceta Hue in the laboratory experiments. The arrows indicate compounds that were utilized and the probable routes by which these compounds were absorbed (either as intact molecules or as ammonium). The results indicate that urea is hydrolyzed and glutamine and asparagine deamidated by extracellular enzymes, yielding ammonium. Only amino acids with nonpolar sidechains were u tilized to any significant degree. A special absorption mechanism may exist for the two related compounds, uric acid and xanthine. 40

cell permeability is limited to ammonium ions (or, more specifically,

to ammonia molecules), lipophilic amino acids, and a few specific compounds such as uric acid and xanthine. Amino acids probably are not found to any great extent in guano, and most would be charged molecules that would not be able to enter the cells. If the mycobiont is in fact permeable to n itra te , then the nitrate apparently is not reduced in the cells to ammonia because the appropriate enzymes are lacking.

Results of the Temperature Experiments.—The results of the two temperature experiments are presented in Graph V, from which i t can be seen that the temperature curves for both mycobionts were clearly bimodal in the f ir s t experiment. There was less growth at 11 C than at higher or lower temperatures. The curves are remarkably sim ilar, especially when the great difference in inoculum dry weights is con­ sidered. The two optima for Lichen B (Lecidea sp.) were in the vicinities of 7 C and 15 C; those for Lichen A (U tephroeceta), 3 C and 19 C. The results of the second experiment with Lichen A (Graph V, inset) are puzzling in comparison with those of the fir s t: the peak in the temperature curve at 3 C is absent at th irty -th re e and f if t y - three days, and at eighty-four days as w e ll, where, however, i t can be seen that growth had greatly accelerated at 9 C and 14 C and had virtually ceased a 4 C. This disparity between the results of the first and second experiments with Lichen A may be due to the presence in the medium used for the firs t experiment of biotin and thiamine and other growth factors. However, the data are too few to determine the factors involved, and further experiments are necessary. 41

a 9 WEEKS a o» £ 4 - A. 18 WEEKS 4 B4 DAYS 53 DAYS LICHEN A LICHEN B

+4 +9 +14 +19 +24 CENTIGRADE

V- —Or

CENTIGRADE

Graph V. Growth of the mycobionts Lecanora tephroeceta Hue (Lichen A) and Lecidea sp. (Ahmadjian #32) (Lichen B) at various temperatures. Inset: Growth of Lichen A in a different medium at five temperatures. 42

The points for eighteen weeks in Graph V represent means of the

dry weights of mycelium from at least five flasks, and in all but one

case (Lichen A at 3 C) for between ten and fifte e n flasks. Examination

of frequency distributions of the dry weights showed that the means

accurately reflect the true weights attained at each temperature. At

3 C, Lichen A yielded a mean of 14.9 mg of mycelium, with values in

the fiv e flasks fa llin g between 13.3 and 16.7 mg. Means and standard

deviations for Lichen A, Experiment 2, 84 days (Graph V, insert) were:

-1 C : 0.97 (0.79); +4 C : 1.12 (0.40); +9 C : 3.83 (1.42); +14 C : 4.00

(1.88); +19 C : 4.31 (1.51); and +24 C : 0.96 (0.89) milligrams. (The

weight of the inoculum, 0.4 mg, was subtracted before the points were

plotted fo r Graph V .) The results of both experiments on temperature

thus appear to be valid, and the reasons for the differences must lie < with the two media employed. This underscores the need fo r care in

interpreting the results: nutrition apparently influenced the effects

of temperature on the growth of L tephroeceta.

I f indeed the mycobionts of Antarctic lichens do have two temper­ ature optima under some conditions, then i t is possible that there are

two enzyme complements that evolved under d iffere n t environmental conditions. If so, then there are at least two possible interpretations of this situation: firs t, that the higher temperature optimum may have

evolved outside Antarctica, the lower optimum evolving in Antarctica a fter the lichens migrated from warmer regions, or second, that the higher temperature optimum may have evolved in indigenous lichens during warmer periods in Antarctica its e lf. Without experimental v erificatio n , this type of speculation is unsafe. 43

Prasiola crispa

Introduction. —Bal1eny Islands Reconnaissance Expedition, 1964.

On 9 March 1964 a helicopter landing was made on Sabrina Island, the

Balleny Islands ( 66°541S, 163°20'E), from the USS Glacier to collect

plants and for other s c ie n tific purposes (Dawson et a l. , 1965) (Map IV).

Terrestrial algae were found on the western slopes of the isthmus

between sea level and about 50 m. Near the top of the slope, Myxophyceae,

Xanthophyceae (Tribonema s p .), and Chlorophyceae (Prasiola crispa

(Lightf.) Kutz. ssp. antarctica Kutz.) were collected. Prasiola was common on most of the slope; at the top of the ridge it appeared to be lichenized. Lichens were very rare, possibly because of high concentrations of salts or because there was little suitable substrate; there were only a few depauperate, sterile specimens of a Xanthoria type near the top of the ridge. No mosses could be found. Ice colored green by algae was collected and returned frozen to the United States, as were soil samples from the top of the ridge. Kol and F lin t (1968) have reported on some algal isolates from the green ice, including a new species of Chlamydomonas, and Wise (1964) has reported on three species of mites he isolated from the algal and soil samples I collected at the same time.

£_. crispa is one of the most common algae in Antarctica (Skottsberg,

1905; Hirano, 1965, inter a lia ). In places, i t may cover large expanses.

For example, Rudolph (1963) found that i t covered approximately 12.8 per cent (range: 0.1 to 89.0 per cent) of a quadrat measuring about

4200 m^ on Seabee Hook near Cape H a lle tt, more than any other species of plant. Rudolph attributed its abundance to moisture and to nitrogen 44

Map IV. Map showing the location of Sabrina Island (arrow), collection site for the Prasiola crigpa used in the nitrogen-source experiment. See Dawson et a l. (1965), Plate 4, which was photo­ graphed from near the collection site, and Kol and Flint (1968). 45

, I63°E 10' 2 0 ' 30' 66°40 SH----- 66®40'S

CAPE CORNISH

CAPE DAVIS

BUCKLE

\ I S L A N D

50' — 50'

SCOTT CONE

CAPE MACNAB

SABRINA ISLAND THE MONOLITH*

67°S-f------67°S 163° E 10 20 30' 46

from penguin and skua guano. Syroechkovskii (1959) arrived at a

similar conclusion for £. crispa growing on Haswell Island.

Experimental Procedures. — Isolation. £. crispa was isolated from a subsample of the green ice collected on Sabrina Island, in a liquid medium containing ammonium oxalate. I t was used in a study of nitrogen-source utilization. The first isolation attempt was made on

19 April from the melted subsample. The pH of the melted ice was about 5.5 some 20 hours after it was placed in constant light at 12 to

13 C on 18 April. It had a distinctly fishy odor.

On 19 April, loopfuls of the resulting algal suspension were placed on agar slants consisting of soil extract, NH4NO3 , urea, and

B ristol's Solution. The inoculated slants were then incubated in con­ stant light at 12 C. No growth occurred. In a solution containing

i only uric acid as a nitrogen source, however, growth did occur.

The remaining sample was refrozen on 20 A p ril. On 1 June, a second attempt was made to isolate algae on the following media:

(1) A saturated, filter-sterilized, aqueous solution of

uric acid, with and without Bristol's Solution;

(2) A filter-sterilized 0.1M solution of urea, with and

without Bristol's Solution;

(3) An autoclaved 0.5 per cent solution of ammonium

* oxalate, with and without Bristol's Solution;

(4) A filter-sterilized 0.5 per cent solution of

ammonium oxalate, with and without Bristol's Solution;

(5) Cyanophycean Medium (liq u id ) (S tarr, 1964);

( 6 ) Beneche's Nutrient Solution (Cavanaugh, 1956). 47

The basic media were dispensed in 50-ml aliquots to 125-ml erlenmeyer flasks. To Media (1) through (4 ), 5 ml of B risto l's Solution were added to half of the flasks, giving a total of 55 ml of medium per flask.

Growth Experiments. On 27 October, pieces of Prasiola crispa approximately 0.5 to 1.0 cm in diameter, which had developed in Medium

(3) (with 5 ml Bristol's Solution) were transferred to 25-ml flasks containing 15 ml of a medium consisting of equal amounts of soil extract diluted 1:3 with distilled water and of Bristol's Solution minus FeClg.

By the time of this transfer, the formerly bright-green algae had begun to turn yellow.

The inoculated flasks were incubated at about 5 C in continuous light for two days, when 2 ml of the following solutions were added:

Uric acid. Filter-sterilized Bristol's Solution with uric

acid (0.0665 g/1) replacing the NaN 0 3 ;

Xanthine. Filter-sterilized Bristol's Solution with xanthine

(0.062 g /1 ) replacing the NaN 0 3 ;

Urea. Filter-sterilized Bristol's Solution with urea

(0.475 g/1) replacing the NaN03,

In each case, 20 ml/1 of phosphate buffer, pH 7.0, were used instead of the prescribed phosphate s a lts , and one drop of a 1 per cent aqueous solution of FeClg -6 W fl was added to each lite r of the resulting solution. An equal number of flasks containing the above media plus

2 per cent agar were also inoculated, but growth was poor because of contaminating microorganisms. The flasks were incubated at about 5 C in constant lig h t of approximately 1500 lux. Growth was excellent in all three liquid media numerous long, bright-green narrow thalli arose from the original dying inoculum.

The algal thalli resulting from growth in the above three media were combined, washed with s te rile d is tille d water, added to about

350 ml of nitrogen-free B ristol's Solution, and homogenized in a Waring blender for about 15 seconds. On 18 March 1965, the resulting algal suspension was pipetted, in 2-ml aliquots, to the following media:

(1) Equimolar (3.5 x 10“^ M) filter-sterilized solutions of

uric acid, xanthine,, and allantoin made up in Bristol's

Solution lacking NaNOg, and containing equal amounts of

nitrogen (0.0196 g/1) (uric acid: 0.0588 g/1; xanthine:

0.0532 g/1; allantoin: 0.0553 g/1). The uric acid and

xanthine, were dissolved f ir s t in a small amount of 0.5 jl

NaOH.

(2) Solutions of urea, NH^Cl, NH^NOg, and NaNOg, made up in

Bristol's Solution minus the NaNOg, and containing

approximately 0.1648 g nitrogen per l i t e r , the amount of

nitrogen in 1 g of NaNOg (urea: 0.353 g/1; NH 4C I: 0.629

g/1; NH4N03: 0.4708 g/1; NaNOg: 1.000 g/1).

(3) A double-strength (0.9416 g/1) solution of NH^NOg made up

in nitrogen-free Bristol's Solution.

(4) A solution consisting of (a) autoclaved nitrogen-free

B risto l's Solution plus 0.5 g/1 NH^NOg, pH adusted to

6.0, and (b) filter-sterilized, nitrogen-free Bristol's Solution plus 0.0266 g/1 xanthine and 0.1765 g/1 urea,

pH adjusted to 6.0. Part (b) was added to Part (a) in

the ratio 1:28, giving a final xanthine concentration

of about 0.9 mg/1 and a fin al urea concentration of

about 5.9 mg/1.

(5) Medium (1) with xanthine plus 0.0121 g/1 of gibberellic

acid (75 per cent K salt).

( 6 ) Medium (2) with NH NO plus 0.0121 g/1 of gibberellic t o acid (75 per cent K salt).

(7) Medium (2) with NaNOg plus 0.0121 g/1 of gibberellic

acid (75 per cent K salt).

(8 ) Medium (2) with NaNOg plus 0.0753 g/1 kinetin (dissolved

f ir s t in 25 ml 0.1 N^HCl).

(9) Bristol's Solution plus thiamine (100ug/l) and/or

Biotin (5p:g/l).

Except for Medium (4 ), the algae were incubated in continuous fluorescent lig h t for fifty -o n e days at 15 C in 25-ml erlenmeyer flasks containing 20 ml of medium. For Medium (4 ), 50-ml flasks and 30 ml of medium were used. Each flask was inoculated by pipette with 2 ml of the blended algal suspension. The average dry weight of inoculum was less than 0.1 mg/flask, as determined by twenty-one dry-weight determinations. The results are presented in Table 4.

A separate series was set up a t the same time fo r a rough compari­ son of growth a t 5, 10, 15, and 20 C. Medium (4 ), 50-ml flasks, and

30 ml of medium were used. Because i t was impossible to have identical light intensities at each temperature and for all flasks at each TABLE 4

GROWTH OF Prasiola crispa FROM THE BALLENY ISLANDS ON VARIOUS NITROGEN

SOURCES AND WITH ADDED GROWTH FACTORS^3)

Grown in liquid culture for 51 days a t 15 C under 970 lux of continuous lig h t.

Nitrogen Source Concentration Dry-Weight of Final and Additions Medium(b) of Nitrogen, g/1 Alga, mg(c) pH

Uric acid ( 1) 0.019 3.5 (3.3-3.6 ) 7.0 Bright-green, large th a lli Xanthine ( 1) 0.019 1.5 (1.4-1. 6 ) 6.2 Allantoin ( 1 ) 0.019 0.9 (0.8-0.9) 6 .2 Light green Urea ( 2) 0.165 1.4 (1.1-1.6 ) 6 .2 NH4NO3 ( 2 ) 0.165 1.3 (1.2-1.4) 4.5 NH4NO3 (3) 0.330 ' 1 .2 1 . 1- 1 .5) 4.9 NaNOo ( 2) 0.165 1.7 (1.3-2.2) 6.7 nh 4ct ( 2 ) 0.165 1 .2 ( 1 . 0- 1 .5) 4.5 Xanthine (0.9 mg/l)+ Urea (6.0 mg/1) + NH4NO3 (0.5 g/1) (4) 0.172 1.5 (1.4-1.5) 6 .0 Xanthine + gibber- e llic acid (5) 0.019 2.3 (1.7-2.8) 6.1 NH4NO0 + gibberellic acid ( 6 ) 0.165 1.4 (1.1-1.5) 4.5 NaNO-j + gibberellic acid (7) 0.165 1 .2 ( 1 . 1- 1 .4) 6.5 NaN03 + kinetin (8 ) 0.165 0.4 (0.4-0.6 ) 6.1 Yellowish to brownish- green in color; { least growth of a ll. TABLE 4 .—Continued

Nitrogen Source Concentration Dry-Weight of Final and Additions Medium(b) of Nitrogen, g/1 Alga, mg(c) pH(d) Remarks

NaNOj + biotin (9) 0.165 2.2 (1.9-2.4) Contaminated with a white yeast NaN03 + thiamine (9) 0.165 • 3.1 (2.8-3.7) 7.0 Di tto NaNO^ + biotin and ii thiami ne (9) 0.165 3.5 (2.8-4.1) 7.1

(a) Prasiola crispa ssp. antarctica from the Balleny Islands (66°53'S, 163°19'E), originally isolated in a medium containing ammonium oxalate. The original sample was in the form of green ice (cf. Kol and Flint, 1968). ^ The media are described in detail in the text.

The dry-weight values are the averages of three flasks. The ranges of weights are given in parentheses. The dry-weight of the inoculum (average of 21 aliquots) was less than 0.01 mg/flask. ^ Values are the pH's of the combined filte re d medium from three flasks. The in itia l pH values were not determined. 52

temperature because of physical lim itations, visual observations only were made. No growth occurred at 20 C; th a lli were white and, presum­

ably, dead. Thalli that grew at 10 C were yellowish green, and there was l i t t l e apparent growth. T h alli that grew a t 5 C were lig h t green;

they appeared to be healthy and to be growing actively.

Discussion.—The results clearly indicate that _P. crispa grows best on uric acid, which is the principal form in which nitrogen is excreted by birds. With uric acid as nitrogen source, the alga was large, healthy, and bright green in appearance. At the time of collection, there were numerous moulting penguins on Sabrina Island (Dawson et a l .,

1965), and on part of the island there was a rookery of some 1500 to

2000 birds ( ib id . ). Cape Pigeons ( Daption capensis) and Snow Petrels

(Pagodroma nivea) also were nesting on the island. These birds were undoubtedly a source of uric acid.

£_. crispa is found almost exclusively in moist places near bird rookeries. Examination of specimens in a number of herbaria confirmed the nitrophilous character of this species, as did a review of the litera tu re on £. crispa from Antarctic, A rctic, and north temperate locations. The present experimental results indicate that uric acid is one important factor responsible for the observed correlation between birdlife and the distribution of F\ crispa.

Compounds that are closely related to uric acid (viz. , xanthine and allantoin) supported significantly less growth than uric acid.

Allantoin, in particular, was a poor source of nitrogen. Urea, ammonium s a lts , and n itra te salts supported approximately the same amount of growth as xanthine. The plant growth substance gibberellic acid had a 53

stimulatory effect in combination with xanthine, an inhibitory effect

in combination with NaNOg, and no significant effect in combination

with NH4 NO3 . In combination with NaNO^, kinetin had a very definite

growth-inhibiting effect on the alga. Thalli grown in the presence of

kinetin were small and yellowish- to brownish-green.

The results obtained with the vitamins thiamine and biotin are

unreliable because the vitamins stimulated growth of what appeared to be a single species of yeast that was associated with the alga. Although

the dry weight of £. crispa was significantly greater when vitamins were present, the conclusion that vitamins per se stimulated growth of the alga on nitrate is untenable because it is quite likely that the yeast transformed the nitrate to a more suitable nitrogen compound. At least that possibility cannot be ruled out in this case. Microscopic examina­ tion of the contaminated growth medium indicated that the same yeast may have been involved in each case, and that the contamination seemed to be essentially a pure culture of one yeast, although a definite id en tification was not attempted. As seen through the microscope, the yeast was white and the cells had longitudinal divisions in some cases.

There was some pseudomycelium with yeast-like conidia at the tips.

Because the standard mycological techniques necessary for identifying yeasts were not employed, i t cannot be stated that only one species was in fact present.

Since the inoculum used in this study came from material f ir s t isolated in a medium containing oxalate, other organic acids—particularly glyoxylic acid, which is produced by the enxymatic hydrolysis of allantoin, and glycolic acid, a well-known extracellular compound that is related 54

chemically to oxalic acid--should be employed in future studies of

P. crispa. Oxalic acid (COOH-COOH) is produced in a single metabolic

step from glyoxylic acid (CH0-C00H). Guano and soils from rookery areas should be tested for the presence of these and other organic acids.

The results of this experiment could be rejected because the material was unialgal and not axenic. The following facts indicate that, except in the case of the media with the vitamins, the results can be accepted with re lativ e confidence: ( 1 ) the basic medium was essentially a mineral solution (j_.£., i t contained no carbohydrate or carbon source), which means that only autotropic organisms could grow in i t ; (2 ) no visib le growth of contaminating organism(s) occurred except in the media with vitamins; (3) neither xanthine nor allantoin supported as much growth of Prasiola as uric acid, an indication that uric acid was u tilize d by the alga as such, not after transformation by contaminating organisms to some other nitrogen compound. Neither urea nor ammonium supported as much growth as uric acid. I t can safely be stated that any contaminating microorganisms were present in negligible amounts and had negligible influence on the results, except in the media that contained biotin and/or thiamine.

Holm-Hansen (1964) and Kol and F lin t (1968) fa ile d to isolate

P. crispa from samples from the McMurdo Sound area and from the Balleny

Islands, although Holm-Hansen saw Prasiola in preserved samples from

Cape Crozier (probably F\ crispa) and from Taylor Valley (possibly P_. calophylla); the J\ crispa used in the present study was isolated from a subsample of the same green ice used by Kol and F lin t. None of the 55

media used by Holm-Hansen or Kol and F lin t contained uric acid, urea,

or organic ammonium salts. Their failure to obtain Prasiola can

reasonably be attributed to their use of unsuitable sources of nitrogen.

Bryum algens

Introduction. —A specimen of moss, collected in the Jones Mountains,

Eights Coast, West Antarctica, by Mr. Kelvin P. Rennell, and referred by

Dr. Stanley W. Greene, on the basis of cultured m aterial, to .Bryum algens

Cardot, was isolated into axenic culture and used in laboratory studies

of its nutritional characteristics.

The type specimen of J3. algens was collected in the Granite Harbor

area of southern Victoria Land in 1902. The species has been collected

since from, among other localities, McMurdo Sound (islet in old ice) in

East Antarctica; from Deception Island and Petermann Island in maritime

West Antarctica; and from Signy Island, where i t forms compact cushions

along the courses of meltwater streams, in sheltered rock crevices,

and in other moist or permanently wet habitats influenced by basic rocks

and soils in the Moss Hummock Subformation of the Maritime Antarctic

(Gimingham and Lewis Smith, 1970; Longton, 1967).

Dixon (Dixon and Watts, 1918) and C lifford (1957) have reduced

£. algens to synonymy with B_. antarcticum, from which they claim it is

indistinguishable. Greene, Horikawa, and Ando (Horikawa and Ando, 1967) do not concur in this judgment, however.

Isolation. —Eight clones of B^. algens were isolated into axenic culture on 1 March 1964 by cutting the newly elongated tips of about

20 gametophytic green shoots from a clump of moss, rinsing them in 56 ethanol diluted with sterile distilled water, and placing them on

Trebouxia Agar (Ahmadjian, 1967) with biotin (5 mg/1) and thiamine

(lOOpg/1). The eight contamination-free isolates then were transferred to Knudson's Medium in erlenmeyer flasks covered with metal caps and polyethylene film , as described by Ward (1960). Figure 4 is a photograph of one of the clones in axenic culture.

Growth Studies. —Three preliminary studies were made of the response of the isolates to nitrogen sources, growth factors, vitamins, and adsorbing and chelating agents. The object was (1) to survey the nitrogen nutrition of j3. algens; ( 2 ) to determine whether growth factors would induce the sporophytic stage of the organism, which apparently is s te rile in Antarctica; (3) to detect any requirements for vitamins that might play a role in lim iting its distribution; (4) to determine whether mineral deficiencies or mineral to x ic ity might influence its distribution; and (5) to assess the range of morphological variation that the above factors might.induce.

In the f ir s t study, the eight clones were grown on one of a number of media in an attempt to determine the overall variability of the species. Three basic media were used; these were modified by adding so-called microelements and urea. In the second study, fiv e of the eight clones were transferred to medium containing soil extract, with or without minerals solution, carbon source, and/or adsorbing or chelating compound. In the third study, seven nitrogen sources, three plant-grwoth substances, two water-soluble vitamins, a chelating agent, and a vitamin-adsorbing compound were added to the basic medium separately and in combination. In addition, the moss was cultured with an imperfect fungus that had occurred in large numbers in moss communities on Seabee 57

Figure 1. Clonal isolate of Bryum algens from the Jones Mountains, Eights Coast, West Antarctica, in axenic culture (c-f. Gressitt et a l. , 1964). 58

Hook, Cape H a lle tt, to detect any mutual effects on growth of the two organisms. Since other workers (£ .£ ., Sironval, 1947; von Maltzahn and MacQuarrie, 1958) had found that fungi ( Penicillium , e tc .) stimulated growth of mosses, it was possible that the fungal isolate from Antarctica was influencing growth of the associated moss at Cape

H a lle tt.

F irs t Experiment. In this preliminary experiment, the eight clones were grown on one of three basal media that were either unmodified or modified by addition of certain compounds or elements. Clone I was grown on Knudson's Medium (Ward, 1960) without additions, as were

Clones 2, 3, and 4. Clone 5 was grown on Knudson's Medium plus micro­ elements ( ib id.). . Clone 6 Was grown on Bristol's Solution Agar with.

0.001 M urea (added as a filte r -s te riliz e d solution), and Clone 7 was grown on mmodified B risto l's Solution Agar. Finally, Clone 8 was grown on Soil Water Agar. A ll media except the B ristol's Soiution and

B risto l's Solution plus urea were so lid ified with 15 g agar per lit e r of fin al medium; fo r the two exceptions 20 g of purified agar were used.

The moss was incubated f ir s t at a temperature of 11 C under continuous cool-white fluorescent lig h t. During an unavoidable interim period of about nine days, i t was grown at various temperatures, under fluctuating light intensities, and in different photoperiodic regimes

(fo r four days, in the dark at 6 C or under fluctuating illumination at

15 C, and then for fiv e days with an approximately working-day diurnal photoperiod at room temperature). The moss was then incubated a t 12 C and 14 C under continuous cool-white illumination. The results of

Experiment 1 are presented in Table 5. 59

TABLE 5

GROWTH OF ALL EIGHT CLONES OF Bryum algens Cardot ON VARIOUS MEDIA (EXPERIMENTS)

On solid media in 250-ml erlenmeyer flasks with metal caps covered with polyethylene, between 11 C and 15 C in continuous cool-white fluorescent lig h t (see text for complete details).

Clone(s) Age, months Medium Growth

Knudson's Restricted to remnants of old Medium^3' medium (Trebouxia Agar plus biotin and thiamine). Appar­ ently inhibited by new medium. 1.75 x 0.8 cm. Three shoots. Protonemata green, restricted to Trebouxia Agar.

2, 3, 4 Knudson's Same as that of Clone 1, although Medi urn somewhat larger. Edges of colony turning reddish brown.

Knudson's Almost completely absent, Brown Medium plus (apparently dead). microele­ ments^)

4.6 Bristol's Green, except for some brown-green Solution leafy shoots. Good protone- plus 0.001 matal growth. Three shoots. M urea(c ' Restricted growth (0.6 to 0.7 cm diameter).

4.6 Bristol's Excellent growth, a ll of i t lig h t Solution green. Approximately 50 shoots without urea of almost 1 cm in height. Ap­ (2% purified proximately 1.5 cm in diameter. agar) 60

TABLE 5 .—Continued

Clone(s) Age, months Medium Growth

8 4.8 Soil,Water Excellent, healthy, green, spread Agar(e^ ing growth. Numerous green shoots about 1 cm t a ll. Approx imately 3.5 cm in diameter (green shoots occupying the inner 1 to 2 cm, the proto- nemata, a 1-cm-wide zone outside the shoots).

^Sucrose, 10 g/1; NH4N03, 0.5 g/1; KH2P04 , 0.2 g /1 ; MgS04 -7H20, 0.2 g/1; CaCl2*2H2 0 , 0.1 g/1; and agar, 15 g/1. (^The microelements were present in the following fin al concentra­ tions: B (as HqBOo): 30 yg/1; Mn (as MnS04 *H2 0 ): 30 yg/1; Zn (as ZnS04 -7H20 ): 130 y g /1 ; Cu (as CuCl2 *2H20) : 27 y g /1 ; Mo (as M0O3 ): 15 yg/1; and Fe (as FeCl 3 *6H20): 250 yg/1. (c) < The urea was s te rilize d by filtr a tio n . Purified agar (Difco) was used at the rate of 20 g /1 .

^ U n d ilu te d soil water ( Ahmadjian, 1967, p. 121) with agar (15 g /1). Second Experiment. In the second experiment, Clones 1, 2, 3,

4, and 6 were grown in four flasks of each of the following five media:

Medium la: Soil Water Agar (made according to directions in Ahmadjian

(1967, p. 121)); Medium lb: a different batch of Soil Water Agar that was darker in color than Medium la; Medium 2: Soil Extract Agar (soil water plus distilled water, 3:4) plus Bristol's Solution (10:1);

Medium 3: Medium 2 plus glucose (1 g/1); Medium 4: Medium 2 plus activated carbon (Norit-A) (10 g /1 ); and Medium 5: Medium 2 plus gibberellic acid (75 per cent K salt) (about 0.01 g/1). To each of these media except the la s t, 15 g of purified agar (Difco) were added per lit e r of medium. Ordinary.agar (Difco Bacto-Agar) was used with

Medium 5. The inoculated flasks were placed in continuous cool-white fluorescent light at a temperature of approximately 14 C. Results are given in Table 6.

Third Experiment. Clone 6 was used in a third study of nutritional response. Uric acid, xanthine, allan to in, urea (three concentrations),

NH^Cl, NaNOg, NH^NOg (two concentrations), gibberellic acid, kinetin, thiamine, and biotin were supplied in the amounts given for the nine experimental media employed in the study of Prasiola crispa (Media (1) through (9 )). Indole-3-acetic acid (IAA) (0.06131 g/1; f i l t e r sterilized); Norit-A (5 g/1); and ethylenediaminetetraacetic acid

(EDTA; dissolved firs t in K0H in the ratio 50:31) were added to Bristol's

Solution alone and in various combinations. Urea was supplied in con­ centrations of 0.021 g/1, 0.042 g/1, and 0.353 g/1, and NH^NOg in concentrations of 0.4708 g/1 and 0.9416 g/1. A fungus (AF-132), isolated 62

TABLE 6

GROWTH OF FIVE CLONES OF Bryum algens Cardot ON SOIL-WATER MEDIUM WITH VARIOUS ADDITIVES (EXPERIMENT 2)

In cotton-plugged 50-ml erlenmeyer flasks at approximately 14 C under continuous cool-white fluorescent lig h t. The medium used is described in the text.

Approximate Medium^3) Habit Number.of Shoots'*5)

Clone 1

la Raised; lig h t brownish green, with some 1 red. Protonemata diffuse.

lb Raised; lig h t reddish green (greener in 20 center); f la t and brownish around edge.

2 Good growth; brown toward center, bright 15 green around edge.

3 Reddish brown in center. Shoots green. 40

4 Excellent green and healthy growth. 100 Shoots from sides of shrunken agar.

5 Spreading; raised in center; greenish- 20 brown. Edges brownish.

Clone 2

la Very l i t t l e growth. Green to brownish 15 green. Shoots light green.

lb Raised; lig h t reddish green (greenish in 20 center); f la t and brownish around edge.

2 Very good growth; not bright green. 40 Protonemata dark brownish.

3 Reddish brown in center. Shoots green 40

4 Excellent green healthy growth. Shoots 100 coming from sides of agar. 63

TABLE 6 .--Continued

Approximate Medium^3) Habit Number of Shoots'*5)

Clone 2, Continued

5 Brown. Protonemata reddish brown. 7

Clone 3

la Large amount of dull-brown or red growth. 1

lb Raised; lig h t reddish green (greenish in 25 center); f la t and brownish around edge.

2 Very good growth; not bright green. 30 Protonemata dark brownish. Shoots smaller than those of Clone 2.

3 Reddish brown in center. Shoots green. 40

4 Excellent, somewhat compact, growth, nearly 80 to edge of agar.

5 Dark greenish brown in center, green and 3 spreading around edge.

Clone 4

la Very l i t t l e growth. Shoots lig h t green. 25

lb Raised; lig h t reddish green (greenish in 35 center); f la t and brownish around edge.

2 Darker, brownish green in center, green 20 and spreading around edges. Shoots small.

3 Dark brown; spreading. 50

4 Excellent growth, to edge of agar (less than 80 Clones 1, 2, and 3).

5 Brown. Ptotonemata reddish brown. Shoots 30 small. 64

TABLE 6 . —Continued

Approximate Medium^3) Habit Number.of Shoots^)

Clone 6

3 Green, raised. 17

4 Excellent growth (less than Clones 1 80 through 4 ).

5 Bright green. Protonemata sparse. Shoots 20 ta ll, healthy.

(a^The media are described in the text. (k^Mean values for the six media are: Medium la (four clones only): 10.5 shoots; Medium lb (four clones only): 25 shoots; Medium 2 (four clones only): 25 shoots; Medium 3 (a ll fiv e clones): 35.4 shoots; Medium 4 (a ll five clones): 88 shoots; and Medium 5 (a ll five clones): 16 shoots. 65 on Malt Extract Agar from soil under moss near H allett Station, was inoculated onto Bristol's Solution Agar (solidified with 20 g purified agar per l i t e r ) , and the moss was added two days la te r. The fungus was very common in the vicinty of the Adelie Penguin rookery on Seabee

Hook a t Cape H a lle tt, and had been isolated from various substrates on a number of occasions. I t resembled most closely members of the form genus Phoma.

The inoculated flasks were incubated at 15 C for the f ir s t f if t y - fiv e days in continuous unilateral cool-white fluorescent lig h t. Light intensity was not measured, nor was it exactly the same in every flask, but was most lik e ly between 250 and 1000 lux in a ll cases. After the f ir s t fif t y - f iv e days, the incubation temperature was 10 C; diffuse cool-white fluorescent light was used. The results of Experiment 3 are given in Table 7.

In all three experiments, the media were inoculated with the moss by transferring small pieces of the eight clones with a s te rile inocu­ lating spear. Since the usual procedures for measuring dry weight were unsuitable fo r jl. algens, which had to be grown on solid medium, yield was estimated qualitatively by noting the color and conditions of the shoots and protonemata, and semiquantitatively by measuring the diameter of growth, by counting the number of new shoots, and by estimating the sizes of the "leaves" and shoots.

Results and Discussion. —The results indicate that a ll of the nitrogen compounds employed were more or less suitable for jl. algens, although ammonium salts were somewhat superior. Since urea, uric acid, n itra te s , and, to a lesser extent, allantoin and xanthine, supported TABLE 7

GROWTH OF CLONE 6 OF Bryum algens Cardot ON BRISTOL'S SOLUTION AGAR CONTAINING VARIOUS NITROGEN SOURCES AND ADDITIVES (EXPERIMENT 3)

After 2 months' growth at 15 C in constant unilateral lig h t and an additional 4 months' growth at 10 C in constant diffuse cool-white fluorescent light. Listed in order of growth after 6 months. The medium used is described in the text.

Nitrogen Source H a b its Shoots Protonemata and Additives^ 2 Months 6 Months 2 Months 6 Months 2 Months 6 Months

nh4no3 Spreading; Best growth. Numerous and — Spreading; — green; ab- large in few small bundant. center; small­ shoots. Very good er and fewer Brownish- growth. along proto­ tipped and nemata. aerial in center.

NA4N03 plus GA Lighter in Numerous. Extensive, color, small­ green, with er than with numerous NH4N03 alone. shoots.

nh 4ci Good growth. Lighter, Few, small Greenish; — t Tendency to somewhat on proto­ dark to lig h t grow perpen­ ■ smaller than nemata. reddish-yellow dicular to with NH4N03. green near tips. lig h t. Aerial in < center. * TABLE 7 .—Continued

Nitrogen Source Habi t(b) Shoots Protonemata and Additives^3' 2 Months 6 Months 2 Months 6 Months 2 Months 6 Months

NH4N03 (X2) More compact Relatively Tips Healthy, but growth, dark­ abundant on brownish- not spreading. er in color, protonemata red. Green. than with and numerous one-half in center. concentration.

NaNO-, plus Compact; Greenish, None. — —— — Green. biotin growth late compact in starting. growth.

Xanthine plus Protonemata Brownish- None. Slender. ' Healthy — GA only. green; more green; exten­ compact than sive, flat, those above. not spreading.

NaNOo plus Light yellow­ Numerous; Long, Good growth — thiamine ish green. large in slender. with numerous center, small shoots. small on protonemata.

NaNOg plus Light (not Numerous Numerous, Light green; — biotin and yellowish) in center, long, spreading. O thiamine green. none on slender. •n J protonemata. TABLE 7 .—Continued

(b) Nitrogen Source Habit Shoots Protonemata and Additives^ 2 Months 6 Months 2 Months 6 Months 2 Months 6 Months

Urea (0.353 g/1) Spreading; Healthy, Numerous, Long, slen­ Extensive, Green, equal­ mostly not compact, large, red­ der, lig h t light green, ly distributed, superfi ci al somewhat dish green yellowish with few, of equal radial spreading. in center, green. dark, small length. D efinitely few, dark, shoots. circular; small on ci rcumference protonemata. well defined. Best of three urea concen­ I II. trations.

Uric acid Extensive, Spreading. Few in cen­ Green, Bright green; Light green spreading. te r; those elongating; growing down (lig h t brown- Brownish on protone­ slender. into medium ish red in toward per­ mata mostly (photo- spots), iphery. on side phobia?). Tends to be opposite photophobi c. lig h t.

00 TABLE 7 .—Continued

Nitrogen Source Habit^) Shoots Protonemata and Additives^ 2 Months 6 Months 2 Months 6 Months 2 Months 6 Months

NaN03 plus Mostly proto- Spreading, Numerous, Long; lig h t Extensively Brownish or kinetin nemata, grow­ small, dark green. spreading; greenish. ing in radi­ on protone­ light green, ating arcs mata. One somewhat from center. large shoot brownish or in center. reddish. Brown and aerial in center.

Allantoin Green. Somewhat Few, small Long, slen­ One and in Brownish and spreading. on protone­ der, crooked; agar. Photo- greenish, mata. Two few. phobic. large shoots Green; those in center. on surface brownish green.

NaNO. Tendency to Spreading. Large, num­ Numerous; Tendency to — grow perpen­ Healthy, erous, esp long, green. grow perpen­ dicular to somewhat pecially in dicular to lig h t. lig h t green. center; lig h t. Green smaller to­ to dark green. wards tips of protone­ mata. VO TABLE 7 .—Continued

Nitrogen Source Habit(b) Shoots Protonemata and Additives^3) 2 Months 6 Months 2 Months 6 Months 2 Months 6 Months

Xanthine Spreading. Healthy, Very few, Very long, Strongly Reddish brown. somewhat very small slender. photophobic. light green. shoots on Spreading. protonemata. Only two large shoots in center.

Urea (0.0420 g/1) Acentric Spreading, Photophilic. Light green, Photophobic, Brownish red. growth due In rows somewhat growing into to pronounced along proto­ yellowish. agar, espec­ photic re­ nemata on ia lly on side sponse. side away toward lig h t. Shoots on from lig h t. Less extensive protonemata Large, lig h t on lighted in definite green in side, redder zone separ­ center. on side away ated from from lig h t. those in center.

Xanthine plus Very dark Spreading, Very numer­ Few, long Brown. Aer­ Greenish to ki neti n green. Con­ ous, small, slender. ia l in cen brownish. centric, lighter Heal thy te r. regular green, on green "S, growth pat­ protonemata bases. c tern. Mostly TABLE 7 .—Continued

Nitrogen Source Habit^b) Shoots Protonemata and Additives^ 2 Months 6 Months 2 Months 6 Months 2 Months 6 Months

Xanthine plus superficial. ' kinetin, Slightly continued photophobic.

Urea (0.021 g/1) Spreading Spreading. None in Chi orotic, Brownish Almost com­ and more center. long. in outer pletely extensive Very numer­ two-thirds. brownish. than in ous on medium with protonemata twice as on side away much urea. from lig h t. Subsurface Dark at base, growth green above. noticeably green.

NaN03 plus Compact. Photophilic. Very abun­ Very l i t t l e Norit-A, IAA, Spreading in Numerous, dant; long. growth. and kinetin one direction large (small­ Greenish only (re la ­ er than with yellow, tive to IAA alone, brown near lig h t? ). more numer­ bases. ous than with IAA or Nori t-A alone). TABLE 7 .—Continued

Nitrogen Source H ab it^) Shoots Protonemata and Additives^3) 2 Months 6 Months 2 Months 6 Months 2 Months 6 Months

NaN03 Plus Spreading. Photophi lie . , Numerous. Very l i t t l e Not visib le, Norit-A Very numer­ Long. Green growth. ous. Large. (lig h t green or brownish- red bases).

NaN03 plus Spreadi ng. Photophilic. Fewer shoots Very l i t t l e Norit-A and Numerous. than with growth. IAA Large; kinetin but elongated. longer. Scattered; on periphery.

NaNOo plus No growth. No growth. — Norit-A and Inoculum EOTA brown.

NaN03 plus EDTA No growth. No growth. — — — — Inoculum hwM»m

NaN03 plus GA No growth. No growth. TABLE 7 .—Conti nued

Nitrogen Source Habit(b) Shoots Protonemata and Additives^3) 2 Months 6 Months 2 Months 6 Months 2 Months 6 Months

NaNOo (with Less growth Better growth Fewer, some­ - More shoots More spread- — Phoma sp. and lighter than without what larger than with­ ing than (AF-132)) green than fungus. shoots than out fungus. without without Photophilic without fungus. Fewer fungus. in both fungus. shoots. Numerous cases. pycnidia, but other­ wise sparse fungal growth.

^GA: gibberellic acid (75% K salt); IAA: indole-3-acetic acid; EDTA: ethylenediaminetetra- acetic acid. Norit-A is a conmercial brand of activated carbon. (^'Good growth' or 'healthy growth' is defined as: compact but not restricted growth of a dark green color and with numerous large shoots. 74

growth as w e ll, i t appears that the type of nitrogen compounds in the

habitat of JB. algens is not a c ritic a l factor in its distribution, as

it is with L_. tephroeceta and P. crispa. It is interesting, however,

that the type of nitrogen source did affect the gross morphology of

the moss (c f. Burkholder, 1959), which suggests but by no means proves

that some so-called subspecies and even species may be no more than

ecophenes, attributable to the type of nitrogen source(s) in the

habitat.

For example, Bryum siplei Bartram, which is practically indis­

tinguishable from the cosmopolitan JB. argenteum Hedwig, differing

primarily in its production of axillary gemmae, seems to be found almost without exception where birds occur (c f. Siple, 1938, p. 498; Bartram,

1938; 1957). Bryum argenteum, considered by Horikawa and Ando. (1967)

to be a weedy, nitrophilous species, is not so exclusively found in

close association with birds. Greene (Greene et al_., 1967, p. 12) has

reduced EL sip lei to synonymy with B. argenteum, as had been suggested

by Horikawa and Ando (1961). Further experiments w ill be necessary to

show unequivocally whether nitrogenous or other compounds do in fact modify the morphology of Antarctic mosses.

For some reason—perhaps the presence of sucrose in rather high

concentration—Knudson's Medium, both with and without microelements, was unsutiable for B. algens. The inocula (Clones 1 through 5) did

not grow out onto the new medium, but remained completely on the small remnants of old medium (Trebouxia Agar plus biotin and thiamine). This difference in the suitability of the two media seems not to be attribut­ able to concentration (jk e . , to osmotic factors) because the glucose in 75

the Trebouxia Agar was present in approximately the same molar concen­

tration as the sucrose in Knudson's Medium (0.055 M versus 0.058 M).

I t is therefore reasonable to infer that in some way the sucrose its e lf

inhibited the EL algens.

Bristol's Solution Agar with 0.001 M filter-sterilized urea

(solidified with 20 g of purified agar per lit e r ) supported good growth of the protonemata, but only three green shoots developed, while on

Bristol's Solution without urea there were about fifty . Also, growth was more restricted with the urea (0.6 to 0.7 cm diameter versus 1.5 cm diameter).

Of the three basal media employed in Experiment 1, Soil Water Agar supported the best growth. There were numerous green shoots about 1 cm ta ll, and the diameter of the moss, which was healthy, green, and spreading, extended some 3.5 cm.

In Experiment 2, Soil Water Agar was employed. Two different batches of Soil Water Agar without additives (Media la and lb) yielded somewhat different amounts of growth. Soil Water plus B risto l's Solution sustained very good growth of a ll fiv e clones. With 1 g of glucose per lit e r of medium, there were a few more shoots (an average of th irty -fiv e with glucose compared to twenty-five without). Growth was best on Soil

Water plus B ristol's Solution aid 10 g of activated charcoal per lit e r .

On this medium, growth was healthy and green, and there were almost ninety shoots per clone, some 2.5 times as many as on the next best medium.

Gibberellic acid (GA) did not markedly stimulate growth with

NH^NOg, although protonemata produced in its presence were greener 76

and bore more shoots than those produced in its absence. With xanthine,

protonemata! growth was somewhat stimulated in the presence of GA. The

results obtained with NaNO^ and GA are difficult to explain. Perhaps

the inoculum was insufficient, or died. However, the results of

Experiment 2 suggest that GA in the presence of NaNO^ may in some cases

reduce the amount of growth produced.

Kinetin stimulated protonemata and inhibited shoots somewhat.

Aerial protonemata developed in the centers of the colonies grown on

kinetin, a characteristic that appeared otherwise only with ammonium

salts. The effects of IAA cannot be evaluated because the compound was

added along with other substances.

Protonemata on the medium with NaNC^ and xanthine did not grow

straight outward from the center along ra d ii, but tended to grow outward

in pronounced arcs. This type of growth was not seen in any other case.

Light had a very pronounced influence on both shoots and proto­

nemata. With certain media (e.< 3_.» NH^Cl, uric acid, allan to in , NaNC^,

xanthine, urea at 0.042 g/1 and 0.021 g/1, but not at 0.353 g/1) these

effects were marked. While there was no discernible pattern in the

photic responses, they can be classified into a number of groups:

photophobic growth (protonemata); photophilic growth (shoots); growth perpendicular to the light, growth or initiation inhibited on the side toward the lig h t source (shoots on protonemata); pronouncedly acentric growth on the whole plant, etc. None of these responses was exhibited on every medium; the photic responses sometimes occurred together on the same medium, but not always. I t is impossible to determine whether the photic responses were due to differences in the 77 media or in conditions of incubation such as temperature and light intensity. Further studies will be necessary to clarify this point.

The three concentrations of urea used in Experiment 3 had remarkably different effects on growth, especially on photic responses. With 0.042 g urea per l i t e r , there was a marked photic response; overall growth was acentric and shoots were d efin ite ly photophilic, yet they were produced prim arily on the side shielded from the lig h t. With 0.353 g urea per lite r, overall growth was perfectly circular. Growth on 0.021 g urea per lit e r v/as more spreading and extensive than with 0.042 g, and shoots were long and chlorotic and were more numerous on protonemata shielded from direct lig h t. Protonemata were green with 0.353 g /1, brownish red with 0.042 g /1, and almost completely brownish with 0.021 g urea per lit e r . Preliminary tests of B^. algens on Urease Agar indicate that this species may hydrolyze urea with extracellular urease (more c ritic a l tests must be performed to confirm th is ). Since hydrolysis of urea raises the pH and yields NH^ and COg, the observed differences in protonematal growth could have been due to either pH or nutritional differences among the media. As a case in point, Gimingham and Lewis

Smith (1970) report that B*. algens occurs on basic rocks and soils. A further p o ssib ility is that the lower concentrations of urea were limiting to growth because of a deficiency of nitrogen. Chlorosis, a symptom of nitrogen deficiency in plants, was noted in the shoots of

B. algens grown on 0.021 g urea per lit e r . I t is interesting to note that Holdgate et al_. (1967) concluded that nitrogen was the only element likely to be limiting to plant growth in the Maritime Antarctic.

If so, then the results indicate the extent to which concentration of 78

nitrogen might be a c ritic a l factor fo r the distribution of mosses in

Antarctica.

The vitamins biotin and thiamine appeared to have different effects

on the growth of EL algens. Biotin induced a compact growth habit and

inhibited the production of shoots, while thiamine seems not to have

induced a compact growth habit. Thiamine supported good protonemata!

growth; large shoots developed in the area of inoculation, but there

were only numerous, very small shoots on the new protonemata. With both

vitamins in the medium, shoots were numerous in the inoculated area,

but a fter two months there were none on the protonemata. Biotin seems

to have inhibited growth since, even though the protonemata were green,

no shoots had developed during the two months a fter inoculation. Since

Boyd et al_. (1966) detected three vitamins in relatively high quantities

near the Adelie Penguin rookery on Cape Royds, and found detectable

amounts of the same vitamins in the ice-free valleys of Victoria Land

(they apparently did not test for biotin and thiamine, however), it is

conceivable that mosses growing in the vic in ity of nesting areas could

be morphologically d ifferen t from specimens of the same species growing

in areas where free vitamins in the environment are absent.

The most consistent and convincing effects were produced by

Norit-A and EDTA. Norit-A unquestionably stimulated production of green shoots and apparently suppressed the formation of protonemata.

(Since the medium with Norit-A was black and opaque, i t was impossible

to discern whether significant protonematal growth had in fact occurred, a problem that was compounded by the photophobic nature of the pro­ tonemata.) Since Norit-A is merely activated charcoal, an adsorbing 79

compound used routinely to render media vitamin free (c f. Lilly and

Barnett, 1951, p. 432), the Norit-A in the medium may have adsorbed

substances, such as b io tin , that suppress in itia tio n of shoots.

Adsorption of biotin is but one plausible explanation for the

results obtained with Norit-A, however, since activated charcoal

adsorbs a ll hydrophobic (nonpolar) substances readily. Furthermore,

the stimulation by Norit-A may have been due to light effects, since

the photophobic reaction of the protonemata could have been reduced

by the black, opaque medium that resulted when the charcoal v/as added.

EDTA, which was added in higher than customary amount to the medium ( 1.0 g/1 as opposed to the more common 0.2 g /1), apparently

chelated some essential microelements, such as molybdenum, which is required for the enzymatic reduction of n itra te . Since they were not specifically added to the medium, any microelements present would have to have been background contamination in the reagents used for the medium. The effectiveness of chelation is revealed by the virtual absence of growth in the flasks with EDTA. Such complete sequestration probably would not occur in the fie ld in Antarctica, but some micro­ elements might be lacking in places. Examination of fie ld samples would reveal the extent to which microelements are available to te rre s tria l plants there. Conversely, and more likely to be of significance, the extent to which elements, singly or in combination, might in h ib it growth should be determined, especially in the cold deserts of Continental

Antarctica, where saline soils are the rule. A hint that compounds may in h ib it growth in supraoptimal concentrations is given in Table 5,

where i t is revealed that the addition of microelements to Knudson's 80

Medium apparently suppressed growth even more than the medium its e lf.

This effect might be ascribable to the osmotic characteristics of the

medium. As a further case in point, urea and glucose, when added to

Bristol's Solution Agar and Soil Extract Agar, respectively, apparently

suppressed growth also; it is likely that their effects were osmotic in

nature too. Finally, and most convincing of a ll, when NH^NOg was supplied

at a concentration of 0.9416 g/1, plants were more compact and darker in

color than when it was supplied at half that concentration; in addition,

the tips of the shoots were brownish red on the more concentrated

medium.

There are, howeyer, other plausible explanations of the results.

For example, EDTA readily binds more ions, especially calcium ions, a

deficiency of which would probably have inhibited growth of the moss.

I t is even possible that the EDTA was absorbed by the moss cells; EDTA

could cause problems inside c e lls .

While these studies with B. algens were preliminary in nature and yielded inconclusive results, they nevertheless reveal the potential usefulness of laboratory experiments for interpreting plant distribution and speciation in Antarctica, and also suggest that taxonomic revision should include experimental work.

Field Studies

The results of the laboratory studies formed the basis for the field work of the 1967-1968 and 1968-1969 summer fie ld seasons. The primary objectives of the field work were ( 1) to determine some of the chemical characteristics of soils and waters in plant habitats at selected sites 81

near McMurdo Sound; (2) to monitor selected micro- and macroclimatic

parameters at the same sites; (3) to characterize the distribution of

algae, mosses, and lichens in the McMurdo Sound region; (4) to assess

the influence of the chemical and physical factors on the distribution

of plants; and (5) to evaluate the ecological relevance of the laboratory

growth experiments by correlating the data obtained in the fie ld with

that previously obtained in the laboratory.

Study Sites

Study sites were established in four areas in the McMurdo Sound

region, two on Ross Island, and two in southern Victoria Land (Map V).

Each study s ite or quadrat was approximately square and measured as

close to 20 m on a side as possible.

Quadrat I . —The f ir s t , Quadrat I , was set up on 29 December 1967

in the Cape Royds area about 2 km north-northwest of Shackleton's hut,

downwind of a low knob or knoll in a regions of irregular lava flows at approximately 77°32'12"S, 166°101E (Map V I). There was a narrow, semi­ permanent snowdrift downwind of the knoll, in the quadrat. The elevation was about 50 m above sea level. McMurdo Sound was 0.75 km to the northwest.

Quadrat I I . —Quadrat I I was established on 4 January 1968 at the edge of of skuary on the southeastern slope of an exposed spur or rounded ridge unofficially referred to as "Sugarloaf Ridge," at approximately 77°27, 02"S, 169°13105"E and at an elevation of about 70 m

(Map V II). "Sugarloaf Ridge" lies adjacent to the Ross Sea in the

Williamson Rock area, on the northeast coast of Ross Island some 9 km north-northwest of Cape Crozier. Two nearby Ad^lie Penguin rookeries 82

- 7 6 “ S 76“ S - 160 E 166 E

FRANKLIN ISLAND

A fc TR IP P BAY ALLAN NUNATAK t

BEAUFORT ANITE T) ISLAND "7 7 °S +

CAPE BIRD

CAPE BIRD TENNYSON McMUROO „ ^ILLIAMSON MOUNT I I j&RQCK SOUND EREBUS MOUNT MOU.VfS CAPE ROYO NEW TEI?RA T er R O R ^K HARBOR C A p E BARNE NOVA >CAOE vA*r>tr7 CAPE EVAN^ ROSS ISLAND / £ r c ZIER DAILEY ISLANDS HUT CAPF POINT MAC K AY PENINSULA; BROWN PENINSULA + BLACK ISLAND / (WHITE ^ —^ISLAND u e — MOUNT \ 8 DISCOVERY _ ) . % i “OSNT \ A 7- \ COCKS rflNNA BLUFF MOUNT MORNING SHELF

MOUNT DAWSON LAMBTON

170 E I6 0 °E 79"S •+-

Map V. Map of the McMurdo Sound area of East Antarctica showing the location of Quadrats I through IV. Quadrat I was established on the western tip of Ross Island near Cape Royds, Quadrat I I near Williamson Rock on Ross Island, Quadrats Ilia and Illb on Kar Plateau in the Granite Harbor area of Victoria Land, and Quadrat IV near Miers Valley in extreme southern Victoria Land. Map VI. Contour map of Cape Royds, Ross Island, and vic in ity Quadrat I (small square) is situated in the north-central part of the map. The scale is in kilometers, but the contour interval is 50 feet. From maps of the British Antarctic ("Terra Nova") Expedition, 1910-1913, and of the New Zealand Map Service (Map NZMS 175/13). By permission of the Department of Lands and Survey New Zealand. 84

Rocky Point (360 m)

BROAD SNOW SLOPES

HORSESHOE BAY

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COAST LAKE^ } ] y j ~ ^ \ TERRACED MORAINE IN RIDGESj BLUE MOUNDS, AND SEMICIRCULAR 1 LAKE PLATEAUS

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[PONY LAKE 1 ^v^D E R R IC K POINT . (ARRIVAL BAY CAPE ROYDS FLAGSTAFF POINT BACKDOOR BAY Map V II. Map of the Cape Crozier and Williamson Rock regions of Ross Island. Quadrat II (arrow) is situated on "Sugarloaf Ridge," which is the northernmost snow-free area shown on the map. Based on New Zealand Map Service Map NZMS 175/16. By permission of the Department of Lands and Survey, New Zealand. 86

169*6 E

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ELEVATIO NS IN METERS

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(69-15‘E 87

have a combined summer population of about 350,000 adult birds. The

U. S. Antarctic Research Program's Jamesway hut ("Wilson House") was

situated approximately 1 km to the south.

Quadrats Ilia and I I I b .--Two quadrats were set up on Kar Plateau,

in the Granite Harbor region of southern Victoria Land, at about

76°551S, 162°33'E (Map VII, Figures 2 and 3). The first of them,

Quadrat I l i a , was established on 6 January 1968 in a f la t , exposed area some 2 km northwest of the southeasternmost corner of the plateau at an elevation of about 440 m (Plate I ) . However, because the surface of most of the plateau is a nearly continuous layer of large, angular dolorite boulders, i t was impossible to land a helicopter near Quadrat Ilia at the beginning of the 1968-69 summer season, when there was snow on the ground. Therefore, a second quadrat, Quadrat Illb , was established on Kar Plateau on 21 November 1968 in an area of comparatively lush vegetation at the edge of a small (50-meter- diameter), perfectly circular freshwater pond only 75 m from the south­ east corner of the plateau (Figure 4 ). According to the helicopter's altimeter, the elevation of the frozen surface of the pond was almost exactly 300 m.

I t is very lik e ly that birds v irtu a lly never visited Quadrat Ilia ; skuas did, however, bathe in the small pond adjacent to Quadrat Illb a fter the thick ice melted in midsummer. A number of lichen species that usually are considered to be nitrophilous grew in comparative abundance near the pond, especially, northeast of i t , between the pond and a skuary of some 50 pairs situated on the easternmost tip of the plateau, near sea level. '88

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Map V III. The Granite Harbor region of southern Victoria Land. Quadrats Ilia and Illb were established on Kar Plateau (center of map). 89

Figure 2. Oblique aerial photograph of Kar Plateau ( le f t ) and Dreikanter Head (right) from the east. Granite Harbor is in the foreground. Quadrat Ilia was situated in the center of Kar Plateau in the area of the long, narrow, north-south snowdrifts (1 ), Quadrat Illb near a small pond at the southeastern corner of the plateau (2 ), and the sandstone deposit (3) north-northeast of Quadrat Illb . A skuary v/as found at the base of the plateau along the shore of Granite Harbor. U. S. Geological Survey aerial photograph TMA 397- Exp 0011-F 33 (January 2, 1956). 90 91

Figure 3. A composite of two aerial photographs of the southeastern corner of Kar Plateau. Quadrat Illb (2) was estab­ lished near the edge of a small pond. The sandstone deposit (3) is situated about 0.5 km to the north-northeast. Quadrat Ilia (1) was established about 2 km northweat of .Quadrat Illb in the area of narrow snowdrifts^ and is probably ju st outside the area of the right-hand photograph; lack of id en tifiab le landmarks makes precise location of Quadrat Ilia on the photograph impossible. Mr. Walter G. Burge of the University of Michigan kindly supplied the aerial photographs, which were taken by the United States Navy. ) Vx'j 93

Plate I. Kar Plateau as seen from the south at the base of The Flatiron (A), and a view of Quadrat Ilia from the southwest (B). A stratus cloud was often seen over the plateau, particularly over its western part, during the late afternoon and early evening (B); however, there was no detectable increase of vegetation on the plateau from east to west. On the contrary, there was actually a marked decrease in the occurrence of macroscopic plants westward and away from the coast. 94

■ ■.

< 0

B 95

Figure 4. Enlargement of part of Figure 3 showing the location of Quadrat Illb (indicated by the black and white circles). The asterisks indicate the approximate locations of temperature sites KT 3 and KT 4. The approximate scale is given by reference to the small, circular pond, which was measured when i t was ice covered. The white object in the eastern corner of the quadrat is a very large erratic boulder.

97 Quadrat IV. —On 14 January 1968, Quadrat IV was established in the

southern part of the "McMurdo Oasis," on the top of the ridge that forms

the southern wall of Miers Valley and the northern wall of "Hidden

Valley" to the south, approximately 1.7 km south of Lake Miers and at

an elevation of about 715 m (Plate I I ) . The approximate geographic

coordinates of the quadrat were 78°09'S, 164°00'E. Because of trans­

portation delays caused by the weather, no observations were made during the f ir s t summer at Quadrat IV. During the second season, observations were begun on 30 November 1968.

Quadrat I lies 37 km north-northwest of McMurdo Station;

Quadrat I I , 6 6 km northeast; Quadrats Ilia and Illb , about 137 km northwest; and Quadrat IV , 6 6 km southwest (Map V).

In addition to the permanent quadrats, there were three other study sites. At Cape Royds, a small, circular, alga-filled pond approximately 35 m in diameter and some 75 m southeast of Quadrat I was studied, as was a smaller pond 16 m in diameter, about 375 m northwest of Quadrat IV. A circular deposit of light-colored sandstone

(80 m in diameter), located about 350 m north-northeast of Quadrat Il l b , was studied very intensively because the fruticose lichen Usnea

(Neuropogpn) antarctica DuRietz occurred only in its v ic in ity .

Detailed Descriptions of the Quadrats

Detailed Description of Quadrat I and V ic in ity . —Quadrat I on

Cape Royds consists of a northern portion of a barren knoll formed by an irregular flow of kenyte lava (Treves, 1962), on the north or lee 98

Plate I I . Miers Valley from the east (A) and Quadrat IV from the south (B). The field notebook in B gives the scale. 99 100

side on which is a long, semipermanent snowdrift approximately 15 m in

length; and the western part of a shallow depression, in which a small,

temporary, saline pool sometimes forms (Plate I I I ) . South or upwind

of the knoll, outside the quadrat, there is no snowdrift.

Lichens and mosses are completely absent in the immediate

v ic in ity of Cape Royds its e lf. Lengthy searches over three fie ld

seasons turned up virtually no lichens or mosses closer than 1.3 km

to Shackleton's hut.

The knoll in Quadrat I is typical of the small topographic

features in the Cape Royds region, in that a more or less permanent

snowdrift forms on its downwind flank. Most snowdrifts in the vicinity

of the quadrat have an associated cryptogamic flora that consists of mosses and nitrophilous lichens (Figure 5). In Quadrat I itself, the

cryptogams (especially the lichens) are confined almost exclusively

to the northern side of the kn o ll, on the northern flank of the knoll

its e lf and along the edge of the snowdrift (although not along its

entire length). Also, the plants are abundant where snow accumulates

temporarily, during and for a short time after blizzards, to depths of from 10 to 30 cm. When the quadrat was visited for the firs t time during the second fie ld season (17 November 1968), for example, nearly a ll lichens were covered with snow. Only a few were visib le between the main d r if t and the small temporary snow patch immediately west of i t ; elsewhere, the ground was both bare of snow and devoid of lichens. 101

Plate I I I . Aerial photograph (A) and countour map (B) of Quadrat I , Cape Royds region, Ross Island. The scale of the map is shown in meters at the bottom. The contour interval is 1 foot. Datum is assumed. The original contour map was kindly prepared by K. Eisinger, K. Anderson, F. Brownworth, and R. Todd, U. S. Geological Survey topographic engineers.

103

Figure 5. Distribution of lichens (primarily Caloplaca elegans var. pulvinata (Dodge and Baker) Murray,.a nitrophilous species) parallel to the edge of a permanent snowdrift near Cape Royds sim ilar to that in Quadrat I fo r which nitrogen content and conductance values were determined. The lichens are the lig h t patches on the otherwise dark rocks.

105

On the southern flank of the knoll, where snow never accumulates, mosses and lichens are almost entirely absent; mosses occur only in a few small, scattered patches in the troughs of ice-wedge polygons, in which snow accumulates for short periods of time during and a fte r blizzards (Plate IV).

Mosses are often intermingled with lichens, but they also grow as pure stands in sheltered spots where the soil appears to be more moist than elsewhere. The lichens grow farth er away from the semi­ permanent snowdrifts than the mosses. In some cases, the lichens grow epiphytically on the mosses.

South Polar Skuas ( Catha'racta maccormicki) continually f ly over and near the quadrat, which is located along the flig h t path between the numerous skua colonies to the south (Young, 1963aj and the skuas' main feeding area o ff Cape Bird, some 30 km to the north (Young, 1963b.,

Figure 3). Young (1963aJ estimates that some 71 pairs of skuas nest in the southern and western part of the Cape, while Spellerberg (1967) estimates 57. Just north of the quadrat, no more than 50 m away according to Spellerberg's map ( ib id . ), is the Horseshoe Bay skuary of some 20 pairs (Young, 1963a.; Spellerberg, 1967). One skua nest, probably an outlier of the Horseshoe Bay colony, lay about 70 m south of Quadrat I during the 1967-68 fie ld season; the nest was not occupied during the 1968-69 season, however. There is abundant evidence of skua a c tiv ity near the quadrat in the form of bones, droppings, feathers, etc. There can be no doubt that most of the exposed area of Cape 106

Plate IV. Occurrence of mosses in polygon troughs near Quadrat I , Cape Royds region, Ross Island. The arrows in A point to moss plants; the glove gives the scale. The white arrow in B points to the approxi­ mate s ite at which A was photographed. The aerial photograph, taken shortly after a four-day blizzard, shows that snow accumulates in the troughs of polygons as well as downwind of small topographic obstruc­ tions. The presnece of mosses in the roughs is probably a consequence of three conditions: ( 1 ) the accumulation of snow for short times a fte r storms; (2) protection from wind abrasion; and (3) moister and cooler conditions due to partial shielding from direct solar radiation. The fruticose lichen Usnea ( Neuropogon) antarctica occurs in sim ilar habitats in the Igloo Spur region of Cape Crozier.

Royds—including the vicinity of Quadrat I—is continually fertilized with organic nitrogen in the form of uric acid. The Adelie Penguin

rookery near Shackleton's hut, which consits of some 3200 adult birds

(Taylor, 1962), lie s 2.3 km south-southwest of the quadrat, but the

amount of organic matter transported from the rookery to Quadrat I must be very small because the strongest and prevailing winds are not from the south-southwest (Kidson, 1930; Taylor, 1962; below); in fa c t, winds from the south-southwest are extremely rare and very weak at

Cape Royds.

Prasiola crispa, a sheet-like green alga, grows about 30 m southwest of the quadrat on the top of a knoll where skuas perch. There are also a number of rock and soil lichens nearby, the la tte r in a shallow depression in the rock.

Most of the Cape Royds region is free of snow because the southerly winds that prevail during storms blow snow northward, off the cape and into McMurdo Sound. The stronger the winds, the less snow deposited on land. Map IX, which is redrawn from a report of the British Antarctic Expedition (1907-1909) (Kidson, 1930), shows the general direction of the prevailing winds in the region of McMurdo

Sound. Strong katabatic winds from the south are deflected eastward toward Cape Crozier and westward toward Cape Royds by Ross Island, especially by the massive presence of Mount Erebus, which rises to an elevation of 3497 m. Both capes, which ju t outward from Ross Island 109

Map IX. The approximate wind-flow pattern in the western Ross Ice Shelf--Ross Island and southern Victoria Land region (lines and arrows). Strong katabatic winds blow northward o ff the Polar Plateau and onto the Ross Ice Shelf. Topographic obstructions (islands, mountains, e tc .) divert the winds eastward or westward. The high mountains of Ross Island defelct the northward-flowing winds eastward over Cape Crozier or westward over Hut Point Peninsula and Cape Royds. The intensified winds blow much or most of the capes clean of snow, even during blizzards. Snow usually accumulates only in the lee of topographic obstructions such as hills and ridges. The snowdrifts of Cape Royds and their associated lichens and mosses are directly attributable to this pattern of wind flow, as is the cape's high salinity. Modified from British Antarctic Expedition reports (Kidson, 1930). no

170' 160 165'

-4- ROSS SEA 77° 77' CAPE BIRD -A -o McMURDO SOUND •M T . BIRD \ \ A ROSS M v \ \ \ ISLAND ,CAPE\ / MT EREBUS i \ r o y d s < • r.r;MT. ~Q TERRA

78' 78'

o

---- • MT. DISCOVERY

MT MORNING*;

ROSS ICE/SHELF 79° 79'

160' I65‘ 170' m

proper perpendicular to the direction of the even stronger, deflected winds, are thus swept nearly clean of snow. Only topographic obstruc­ tions like the irregular lava flows near Quadrat I are sufficient to cause snow to accumulate.

Plate V consists of two ae rial photographs of Quadrat I and v ic in ity , one of them (A) taken ju st a fter a four-day blizzard , the other

(B), many weeks after snowfall. Even after the relatively heavy snowfall, most of the area near the quadrat was entirely free of snow; snow accumu­ lated only in the troughs of ice-wedge polygons and downwind of topo­ graphic obstructions (A). The snow cover shown in Plate V A is not greatly more than that shown in Plate V B, despite the great difference in the length of time since the most recent snowfall.

Detailed Description of Quadrat I I and V ic in ity . —Quadrat I I was situated between 65 and 72 m above sea level on the southeast slope of

"Sugarloaf Ridge," which rises abruptly from the edge of the Ross Sea to a height of 86 m, 150 m from the shore (Plate VI). The lower part of the quadrat was permanently covered with snow and ice. Its upper portion was brick-red olivine-augite basalt gravel (Cole et al_., 1971), which became progressively more exposed throughout the summer. Skuas did not nest in­ side the quadrat its e lf, but they did fly over i t continually during the breeding season. Nitrophilous lichens—prim arily Caloplaca spp.—and Prasiola crispa grew within the quadrat, but not mosses, a small clump of which was discovered about 1 m west of the quadrat. The grade or slope of the quadrat varied between 14 and 30 per cent (11 determinations), averaging 22 per cent southeast. 112

Plate V. Aerial photographs of the v ic in ity of Quadrat I immediately a fte r a 5-day blizzard (A) and a longer but unknown length of time after snowfall (B). The numbers locate the quadrat ( 1 ), the snowdrift used in a transect study of soil salinity (2 ), and a small pond southeast of the quadrat (3 ). The white dots in B are the bounds of Quadrat I and the white arrows point to conspicuous surface accumulations of s a lts , which are also obvious around the pond in B. The aerial photography was kindly supplied by J. K. T. Craig, R. Martin, and H. Steiner, all of the United States Navy.

Plate VI. "Sugarloaf Ridge" from the air (A) and from the south (B). The black and white dots in A are the approximate positions of the bounds of Quadrat I I ; the black arrow points to the field investigators, and the triangle indicates a U. S. Geological Survey datum control point at an elevation of 86 m. The white arrow in (B) points to the approximate location of Quadrate I I , most of which is hidden by the snow-free spur in the foreground. The aerial photograph was taken by the United States Navy, and was kindly supplied by Mr. R. C. Wood of The Johns Hopkins University. 115 At the Fourth Consultative Meeting of the S cien tific Committee

for Antarctic Research (SCAR), held in Santiago, C hile, in November

1966, the Cape Crozier region was recommended as Specially Protected

Area Number 6 , in accordance with the "Agreed Measures for the Conser­

vation of Antarctic Fauna and Flora" of the Antarctic Treaty because

i t "supports a rich bird and mammal fauna as well as microfauna and

microflora and . . . the ecosystem depends upon a substantial mixing

of marine and te rre s tria l elements of outstanding s c ie n tific interest"

(Anonymous, 1967, p. 632). Nearly a ll of the work done in the Cape

Crozier area was carried out within the bounds of Specially Protected

Area Number 6 .

While there are many s im ilarities between Capes Royds and Crozier,

there are, at the same time, a number of significant differences. Skuas

and penguins nest in both places, but there are fa r more of both at

Cape Crozier (2,000 versus about 150 skuas and 350,000 versus 2,200

penguins at Crozier and Royds, respectively) (Sladen et al_., 1968).

Both Cape Royds and Cape Crozier ju t outward from the main body of

Ross Island perpendicular to the direction of the strongest winds, which is approximately south in both localities. At times, much of

Cape Royds is nearly devoid of sncw cover, but a large portion of Cape

Crozier is covered with snow at a ll times (Map X). Permanent ice

shelf lies to windward of Cape Crozier, but there are large expanses

of open water south of Cape Royds during la te summer. A ll of these

differences are reflected in the contrasting distribution patterns of

plants on the two capes. C j CAPE BIRI ROSS ISLAND

CONTOUR INTERVAL: IOOO m EDGE OF ICE SHELF MOUNT BIRO EOGE OF FAST OR BAT ICE E 3 FAST OR BAY ICE

CAPE TENNYSON WOHLSCHLAG BAY f 117 Map X. Map of Ross Island showing the locations of the known penguin rookeries. From U. S. Geological Survey map. Used with permission. 118

There are also important differences between the quadrats

themselves. Quadrat I lies more than 2 km northeast of the small Cape

Royds penguin rookery, while Quadrat I I is less than 0.5 km northwest

of the enormous Cape Crozier rookery. Quadrat I is situated near a

number of skuaries, but Quadrat I I actually lie s within the confines

of a skuary that consists of several dozen pairs. The nearest skua nest

to Quadrat I was about 70 m away, while there was at least one nest

within 15 m of Quadrat I I . Most of Quadrat I and its associated flo ra

lay in the lee of a small knoll (less than 100 m 2 in area). By way

of contrast, Quadrat I I and its flora lay on the windward side of a

smoothly rounded ridge (at least 0.12 km 2 in area) (Plate VI, Map Xl).

The flo ra of Cape Crozier is more diverse and abundant than that

of Cape Royds, and there is a richer to tal biota. Plants are not as

restricted in occurrence at Cape Crozier; nevertheless, there are many

sim ilarities between the two lo c a litie s . Because both share a number

of charactersitics, it was possible by comparison to substantiate

inferences drawn from work in one area with those drawn from work in

the other. By the same token, the important differences between the

two areas made i t possible to test preliminary hypotheses about the mechanisms by which environmental factors influence and control the

distributions of plants. In one sense, the combined studies at Capes

Crozier and Royds constituted a scientific experiment: similarities

between the two areas were considered "controls" and differences

were considered "experimentals." The observations were conducted with

this concept in mind, and the data w ill be presented in the same con­

text. 169* 169* t4'0QME

X 7 4 J

100

*7 5

Map XI. Contour map of "Sugarloaf Ridge" showing the approximate location of Quadrat I I (stippled square). Redrawn and modified from U. S. Geological Survey map of Cape Crozier, 1:24,000 (1963). Used with permission. 120

Detailed Description of Quadrats Ilia and IHb and Vicinities.—

Kar Plateau, which is situated on the Scott Coast in southern Victoria

Land adjacent to Granite Harbor, at 76°55'S, 162°28'E, rises gently in

a northwestward direction from an elevation of 300 m a t its extreme

southeastern corner to over 600 m in the northwest (Figure 2). Along

its southern side and in its southeastern corner .are 300-m-high vertical

cliffs. The plateau, which has a more or less level, fla t surface, was

once overridden by ice, as revealed by the occurrence near its eastern

end of morainic deposits. The Larsen Granodiorite constitutes the

bulk of the plateau, but most of this is overlain by a thick sill of

Ferrar Dolerite (i,..e., diabase). Blocks of sandstone that rest on the

surface of the diabase suggest that the granite surface below the

diabase represents the Kukri Peneplain, an ancient surface that occurs

throughout the McMurdo Sound region. Somewhere ju st north of Kar

Plateau, beneath the Marston Glacier, is the Mackay Fault, and east of

it, under water in Granite Harbor, is the Evans Fault. The nearness of

these faults justifies the conclusion that Kar Plateau is a large

downfaulted structure, as does the fact that the Kukri Peneplain (as

indicated by the Larsen Granodiorite) lies at a much lower elevation in

Kar Plateau than i t does ju st north of the Marston Glacier (Gunn and

Warren, 1962).

In the southeastern part of Kar Plateau there are a number of

circular features. One of them is the small pond next to which Quadrat Illb was established (Figure 3). Two of them appear to be

truncated intrusions, although they also may be debris mounds formed 121 by the mechanical disintegration of single blocks of m aterial. Nearby,

350 m north-northeast of the quadrat, is an almost perfectly circular debris mound of Beacon Sandstone some 80 m in diameter. The fruticose lichen Usnea (Neuropogon) antarctica occurs exclusively on this sandstone deposit and immediately downwind of i t (Map X II) .

Both Quadrats Ilia and Illb.were established in diabase (dolerite) areas that are free of snow during most of the summer. Both were in very rocky terrain where soils occur only in small, infrequent patches among and on the rocks, none of them occupying more than 1 or 2 m^.

Vegetation cover in the v ic in ity of Quadrat Ilia was much less than that in Quadrat I l lb , where lichens were almost completely absent.

Quadrats I l i a and Illb were both 400 m 2 in area. In addition to the quadrats, a third study area was established at nearby Point

Retreat, in and adjacent to the deposit of sandstone, in an attempt to determine why Usnea ( Neuropogon) antarctica was restricted to that portion of the plateau.

Detailed Description of Quadrat IV and V ic in ity . —Quadrats I , I I ,

I l i a , and Illb were established in coastal areas. Except for Quadrat

Ilia , which lay approximately 2 km from the coast of Granite Harbor, a ll of them were situated less than 1 km from the Ross Sea (750 m,

150 m, and 250 m, respectively). Both Quadrats I and I I were established in rookery areas, and Quadrat Illb lay next to a pond used for bathing by skuas. Quadrats I through Illb were situated a t re la tiv e ly low eleva­ tions (50 m, 65 to 72 m, 440 m, and 300 m, respectively). Map XII. The distribution of the fruticose lichen Usnea (Neuropogon) antarctica in relation to the sandstone deposit on Kar Plateau. Only the distribution on the dolerite is shown; the lichen was abundant on the sandstone its e lf. 123

Q> GRANITE HARBOR

LOCATION OIAORAM t Sandstone I 'b Dark AREA § Granite X 31 SITES O 2 SITES • 3 SITES 1 i % <§

Troughs Light-colored I boulders

Granite

KEY X <•/ TO 5 X IO'* M* 300 METERS TO SEA LEVEL O 5 TO 10 • IO TO 5 0 m s o t o ( to o POINT RETREAT, KAR PLATEAU Quadrat IV differed from the other quadrats in a ll of these

respects, and thus served as a kind of comparison or control. I t was

set up in the "McMurdo Oasis" at an elevation of 715 m in the "Southern

Foothills" of the Royal Society Range, 25 km from the nearest open

water of McMurdo Sound at Cape Chocolate (Map I I I ) . Actually, its

distance from open water was effectively much greater than 25 km

because ice persists in the Cape Chocolate area until well into summer,

and it returns after only a few weeks. Thus, the effective distance of Quadrat IV from the coast was much greater than 25 km. The fact

that the strongest winds are southerly or westerly in the area further

increases the effective distance of Quadrat IV from open sea water

(cf. Map IX). .

There are no penguin rookeries or skuaries near Quadrat IV; the closest skua nests apparently lie 12 to 14 km to the northeast, near the mouth of Marshall Valley (Spellerberg, 1967). While skuas occasionally stray into the area, their contribution of nitrogen to the terrestrial environment there must be infinitesimal compared with other areas (possibly excluding Quadrat I l i a , which lay 2 km inland from the nearest skuary). On the basis of these facts, one would predict that both moisture and nitrogen occur there in fa r lower amounts than at the other quadrats.

The flo o r of Miers Valley is covered with glacial moraines. The lower portions of its southern wall consist of coarse-grained graphitic marble, schists, and gneisses, which grade into granite at slightly higher elevations. Quadrat IV was established well within the granite 125

area, at the top of the ridge between Miers and "Hidden" Valleys

(Plates V II and V III) (Blank et aTL, 1963).

In the Miers Valley area, and, apparently, throughout the "McMurdo

Oasis," lichens are almost completely lacking from the valley floors.

Quadrat IV was established in January 1968 a fter a careful but

unsuccessful search for lichens on the western end of the valley flo o r.

Mosses were found in sandy, moist spots along "Miers Stream," the

meltwater stream flowing into Lake Miers from Miers Glacier, and in

flushes, along run-off courses, and near patches of snow on the lower

reaches of the valley wall (Plate V III) . Blue-green algae also occurred

in the same types of habitat.

A number of blue-green algae also grew in Lake Miers, a perman­

ently ice-covered, thermally stratified lake, including Nostoe commune,

N. sphaericum, Phormidium frag ile, and Oscillatoria spp. (Baker, 1967);

in addition, Chlamydomonas acuta and Prasiola crispa (mainly the

"Hormidium" stages) were present ( ib id . ). Extensive sheets of blue-green algae (mainly Schizothrix spp.) grew along the edge of the lake (ibid. ; cf. Fritsch, 1912 and Bell et aJL, 1967).

Lichens were sought on the lower parts of the southern wall of the valley, but they were v irtu a lly absent there, except fo r a few soil lichens, which grew in association with a blue-green alga and a moss, in sheltered spots among boulders. Farther up the slope, there were a few scattered patches of Buellia frigida on rocks.

In the immediate v ic in ity of a large, permanent patch of snow near the top of the ridge (Plate VII B: the snow drift just east of the dot that indicates Quadrat IV ), numerous patches of lichens were found, / JOYCE U I GLACIER V \ \

<£>.■— " - MIERS GLACIER" n

C ADAMS GLACIER s . . ______-

Uj O

Plate V II. Map and aerial photographs of the Miers Valley area In extreme southern Victoria Land, showing the location of Quadrat IV. A. Contour map. Quadrat IV is indicated by the cross within the circle (arrow). B. Aerial photograph. The Quadrat (white dot) is located by the white arrow. U. S. Geological Survey TMA 828-Exp 168-F 32. C. Aerial photograph. The corners of Quadrat IV are indicated by the four black dots near the upper right corner of the photograph. The four objects near the center are tents. Photograph by the United States Navy Air Development Sjuadron Six. o

LAKES UR INTERVAL: 400 M.

Miers Valley area in n of Quadrat IV. fcs within the circle ■dot) is located by fp 168-F 32. I indicated by the liotograph. The four k United States Navy 127

Plate V III. Miers Glacier (A) and "Miers Stream" (B). Mosses, but not lichens, grow on sand and gravel along the meltwater stream, which flows from the glacier into Lake Miers.

129

including Ji. frig id a , Omphalodiscus decussatus, and a small fru itin g

Caloplaca. Near the top of the ridge itself, there was a sudden and

dramatic increase in the occurrence of B. frig id a , which appeared to

be confined to one type of granite. Its presence was not related to

exposure (!•£ ., aspect or orientation) or to other factors except,

perhaps, wind direction; however, i t did occur often in depressions on

rocks, no doubt because meltwater collected in the depressions at rare

intervals. The quadrat was set up in the area of greatest concentra­

tion of EL frigida.

The small pond west of the quadrat was in a Targe, circu lar

natural depression. It contained large quantities of macroscopic

blue-green algae, which also occurred as dried mats on soil in a diffuse

ring around the pond, an indication that the pond was larger at one

time, or else was larger at certain times of the year. There were

virtually no lichens in the vicinity of the pond.

A short distance beyond the pond, however, overlooking "Hidden

Valley," B. frig id a began to appear again. Soil lichens occurred in

comparatively large amounts among the fragments of a decomposing rock.

The soil or sand underneath the lichens and rock fragments was stabilized by the presence of the rock fragments, which in one spot were oriented vertically, furnishing a sheltered habitat and a stable substrate for the lichens in the resulting crevices.

On f ir s t examination, the v ic in ity of Quadrat IV appeared to be completely devoid of mosses. Later, however, large quantities of mosses were discovered under a thin layer of sand and rock fragments, a habitat that is probably more moist and subject to lower intensities of sun­ light than the surface itself. 130

Meteorological and Micrometeorological Observations

A program of continuous meteorological and micrometeorological

observations was pursued during the austral summers of 1967-1968 and

1968-1969—at Quadrats I , I I , and Ilia during the f ir s t summer season

and at Quadrats I , I I , Il lb , and IV during the second. Logistical

problems prevented a return to Quadrat IV during the f ir s t season after

i t was established in January 1968, and the im possibility of landing

near Quadrat Il ia early in the season because snow obscured details of the treacherous terrain , made i t necessary to establish Quadrat Illb about 2 km to the southeast.

A ir temperature, re lative humidity, wind direction, windspeed, illumination, solar radiation, solar radiation intensity, duration of sunshine, cloud cover, surface and subsurface soil temperatures, soil moisture content, and barometric pressure were monitored continuously or at set intervals for up to eight days at each quadrat (Table 8 ).

In addition, solar radiation intensity was measured with a Georgi radio­ meter.

Table 9 summarizes the periods during which observations were made in the field.

A ir Temperatures. —A ir temperatures were measured at hourly intervals whenever possible; on a few occasions i t was impossible to record temperatures every hour because of the adverse v/eather conditions. 131

TABLE 8

PROGRAM OF ENVIRONMENTAL OBSERVATIONS MADE AT ALL QUADRATS

Units are the final units in which the recorded values are expressed; in some cases, the original measurements were made in units other than those given here.

Parameter and Units Usual Interval of Observations, h

Measured Parameters

Temperature (s o il, substrate, plant, and air), C

Wind direction at 1.5 m, deg

Windspeed a t 1.5 m, m*sec

Barometric pressure at surface, mb

Cloud cover, okta > eighth)

Description of weather conditions at quadrat(a)

Solar radiation intensity at 0.75 m, lymin.-.-I 2

Illumination at surface, klumen 2

Soil moisture at surface, percent of dry weight

Derived Parameters

Relative humidity, per cent

Dew point a t 2 m, C

(^Symbolic or verbal description. 132

TABLE 9

SUMMARY OF OBSERVATIONAL PERIODS DURING

BOTH FIELD SEASONS

Observations were made at hourly intervals for most parameters. Exceptions are indicated in the table (see note a fte r tab le).

Duration of Obser­ Dates Quadrat vations, h

Austral Summer o f 1967-68

29X1167 1 3

2 I 68 I 6

4 1 68 I I 4

6 I 68 - 7 I 68 I l i a 21

9 I 68 II 10

20 I 68 - 24 I 68 I I 108(a)

31 I 68 - 6 I I 68 I 142(b)

Total for summer: 294 h.

Austral Summer of 1968-69

21 XI 68 - 25 XI 68 I l lb 92

30 XI 68 - 4 X II 68 IV 96

10 X II 68 - 15 X II 68 I I 109

26 X II 68 - 3 I 69 I 209^b)

11 I 68 - 18 I 69 IV 162

26 I 69 - 31 I 69 Illb 124(b)

Total for summer: 792 h.

^Observations not continuous and/or made at irregular intervals. 133

TABLE 9.--(continued)

^Observations continuous and made at regular intervals, but interrupted for two or more h.

NOTE: Slightly more than 1100 h were spent taking observations during the two summer fie ld seasons, 316 h a t Quadrat I , 320 h at Quadrat I I , 234 h at Quadrats Ilia and Illb combined, and 258 h a t Quadrat IV. At Quadrat I , a total of 301 hourly observations were made, 123 the f ir s t summer and 178 the second; at Quadrat I I , 152 observations, 43 the f ir s t and 109 the second summer; at Quadrat I l i a , 22 observations during the f ir s t summer; at Quadrat I l l b , 215 observations during the second summer; at Quadrat IV , 254 observations during the second summer (none during the first). 134 During the 1967-1968 summer fie ld season, a ir temperature was recorded

at a height of 1.5 m with a Wallac Termex Thermoanemometer, Model

GGA2B, and a Wallac NI-125 ANE windspeed and temperature sensor.

During the 1968-1969 fie ld season, temperatures were measured at

heights of 1.5 m, 20 cm, and 10 cm, and occasionally at other heights, with a Yellow Springs Instruments Tele-Thermometer, Model 44TE, and

type 405 probes. The probes were mounted at the appropriate heights on vertical aluminum or steel bars hammered into the ground. The probes were oriented downward, and th e ir sensing elements were shielded from direct sunlight by single strips of masking wound around the protective housings of the probes. The arrangement of the probes is illustrated in Plate IX, as is the telethermometer itself.

Nineteen type 405 probes were available for the air-temperature measurements. All of them were calibrated against at least three sensitive mercury or alcohol thermometers. The differences in tempera­ ture given by the probes and the mercury or alcohol thermometers were very small, usually less than 0.2 C. For this reason, no systematic adjustment of the recorded values was necessary.

Range of Temperatures. —Maximum and minimum temperatures were determined with Taylor Maximum and Minimum Self-Registering Thermometers,

Model 5458 (Taylor Instruments Company, Asheville, North Carolina), which record maximum and minimum temperatures between -30 F and

+120 F. 135

Plate IX. A Yellow Springs Instruments Tele-Thermometer in its protective housing (A ), and the arrangement of the temperature probes (B). A Probe 408 lying f la t on the ground is measuring the soil-surface temperature, and two Probe 405s mounted on a metal rod are measuring a ir temperatures at 10 cm and 20 cm above the surface of the s o il. Short strips of masking tape have been placed around the housings of the two air-temperature probes to shield the sensing element from direct sunlight.

137

The thermometer consists of a glass U-tube f ille d with mercury and an unidentified liquid that expands or contracts with increase or decrease in temperature. The mercury is in the middle of the tube and the unidentified liquid is at either end of the tube. Between each end of the mercury and each pool of the unidentified liquid is a short piece of s te el, the maximum and minimum "indices." The maximum index (in the right-hand arm of the U-tube) remains at the highest temperature gradation reached during a period of observation, while the minimum index (in the left-hand arm of the U-tube) remains at the lowest temperature gradation reached. Both of the indices are reset with a magnet to the current temperature immediately a fte r each reading.

The maximum-minimum thermometers were f ir s t set out during the second fie ld season (in late December 1967 or January 1968). I t was possible to obtain some data for Quadrats I and I I during the 1967-1968 austral summer, but not for Quadrats Ilia and IV. The maximum and minimum temperatures fo r the winter of 1968 were recorded as early as possible the next fie ld season. However, the results were fragmentary and inconclusive because of breakage due to wind and because the minimum temperature was in some cases much lower than -30 F.

During the summer of 1968-1969, maximum-minimum temperature readings were taken at the beginning and end of each stay at the quadrats and, whenever possible, a t irregular intervals during each stay.

The data obtained with the maximum-minimum thermometers are only rough approximations of the actual temperatures encountered by the plants in their natural habitats. The data were gathered for 138

comparative purposes only, in an attempt to detect any consistent

differences in temperature regimes among the quadrats. As neither

the instrumentation nor personnel were available for continuous and

simultaneous recording of temperatures at a ll of the quadrats through­

out the year, the maximum-minimum thermometers had to be adopted as a

convenient though unsophisticated expedient. The systematic errors

in the data do not prevent comparisons among the quadrats. However,

the maximum-minimum temperature data are used primarily in conjunction with the more detailed and much more reliab le data obtained with the

tele-thermometers.

Relative Humidity.--W et- and dry-bulb temperatures were measured every hour at a height of 1.5 m. Psychron Model 566 forced-air psychrometers (Bendix Corporation, Friez Instrument Division,

Baltimore, Maryland) were used during both seasons. This instrument consists of two thermometers mounted side by side, the wet-bulb being covered with a gauze sleeve which is wetted with distilled water, and a small fan that forces a ir over both bulbs, the fan being driven by three heavy-duty Size D dry-cell batteries. A white plastic sleeve shields both bulbs from direct sunlight.

Hair hygrographs were used during the f ir s t season to record relative humidity near the surface, but problems with calibration, the effects of wind, e tc ., rendered the data unreliable. For this reason, the data are not used. 139

. Cloud Cover. —Cloud cover was estimated every hour by visually dividing the sky into halves and then into quarters. The amount of sky obscured by clouds in each quarter (zero, one-half, or two halves) was then estimated and the total value fo r a ll four quarters entered in the data sheets in units of eighths or "oktas." The alternative—to estimate cover in tenths, was not used; i t would have required more time and yet probably would not have yielded any more accurate data because the estimates were only visual.

"Sunniness11.--"Sunniness" was estimated hourly at the time the routine observations were being made. Note was taken of whether the sun was shining on the quadrat its e lf. The data were broken down into categories based on the approximate intensity of the sunlight and the overall appearance of the sky. Full sunlight and a clear sky overhead was indicated by the symbol "S," partial cloudiness by "PC," complete cloudiness by "C," thin cloudiness through which the sun was visible by "V," etc.

Since observations were made only once an hour, the data re fle ct the overall insolation regime only roughly. However, enough observa­ tions were made to permit the sunniness of each quadrat to be estimated and gross comparisons to be made.

Radiation. —Global (sun plus sky) radiation was determined for two-hour intervals with Bellani spherical distillation pyranometers

(metal-coating type) (Physikalish-Meteorologisches Observatorium 140

Davos, Davos-Platz, Switzerland) mounted upright in metal cylinders

(Figure 6 ). Large rubber stoppers with holes held the intruments

securely in th e ir supports, and guy wires kept the supports upright.

The Bellani pyranometer consists of a glass sphere inside of which is a spherical metal-coated receiving surface that absorbs sunlight. Alcohol contained inside the inner sphere is heated and then vaporizes as a result of the absorption by the receiving surface of incident radiation. The alcohol condenses in a glass stem that is attached underneath the sphere. The quantity of alcohol thus distilled is proportional to the amount of radiation that impinged upon the metallic receiving surface.

Illum ination. — Illumination ("lig h t intensity") was determined during the 1967-1968 season with a Photovolt Model 200 lig h t meter (Photovolt Corporation, New York, N.Y.). The sunlight was so strong that a white filte r or "multiplier disk" had to be placed over the probe to reduce the incident illumination to one-twentieth of its initial value. During the 1968-1969 fie ld season, a Tri-Lux Footcandle Meter (P. Gossen & Co.

GMBH, Erlangen, West Germany) was used in place of the Photovolt light meter. A one-twentieth opal "multiplier disk" had to be used with this instrument also.

The Tri-Lux instrument was substituted for the Photovolt instru­ ment because the latter seemed to be affected by the winds, giving somewhat lower values under windier conditions. This was discovered at the end of the 1967-1968 fie ld season, when the Photovolt meter and 141

Figure 6 . Arrangement of a Bellani Pyranometer in Quadrat I . The stem of the pyranometer is inside the aluminum cylinder, which rests directly on.the ground and is secured in place by guy wires. A large rubber stopper with a hole in i t suspends the pyranometer so that it will not vibrate or hit the sides of the cylinder when i t is windy. 142 143 a Gossen meter were compared. The effects of wind were not consistant enough, however, to establish a firm mathematical relationship between the two sets of values. For this reason, the data from the two field seasons are treated separately. There seemed to be no relationship between the ratios recorded during the comparison and such factors as a ir temperature or time of day.

Solar Radiation Intensity.--Solar radiation intensity was monitored during th e '1968-1969 fie ld season with a recording pyrheliometer (Belfort Instrument Company, Baltimore, Maryland,

Catalogue Number 5-3850) (Figure 7), which has a specified accuracy of ±0.15 ly-min-1, a precision of 0.1 ly-min-1, and a response time of 2 min. The dome of the pyrheliometer was laboratory-grade Pyrex glass with a transmission coefficient of approximately 90 per cent for wavelengths between 0.36 and 2.0 nm. The coefficient drops to

50 per cent at about 3.3 nm and to 20 per cent at 40 nm. The u ltra v io le t cut-off value was about 0.28 nm.

The instrument was mounted in a horizontal position on the top of a wooden box which could be fille d with rocks and secured with ropes and metal stakes. This was necessary because the windspeed was usually high, so high at times that a less securely fastened mounting would have been blown away.

In addition, a Georgi radiometer was employed for more precise measurement of solar radiation intensity from time to time. Measure­ ments usually were made a t approximately local noon, beginning at 144

Figure 7 . Belfort recording pyrheliograph, mounted in a horizontal position and secured in place with ropes and rocks near Quadrat I. This instrument records solar radiation intensity with an accuracy of ±0.15 ly min-1 , a precision of 0.1 ly min*1, and a response time of 2 min. The dome of the pyrheliograph is laboratory- grade Pyrex glass that has a transmission coefficient of approximate­ ly 90 per cent for the wavelengths between 0.36 and 2.0 nm; the coefficient drops to 50 per cent at about 3.3 nm and to 20 per cent at 40 nm. The ultraviolet cut-off valve is about 0.28 nm. 145 146

1100 h and ending at 1300 h; occasionally, measurements were made at other times. The values obtained—while very accurate—are of limited value for comparisons because they were obtained at sporadic intervals and were not made simultaneously a t a ll of the quadrats. Since the sun's a ltitu d e varied through the season, measurements reflected the fact that the solar radiation came from varying directions at different times during the summer. The data on solar radiation intensity are presented in Table 10.

Wind Direction and Windspeed. —Wind direction and windspeed were determined by one of two methods. During the 1967-68 fie ld season, wind­ speed was determined with a Wallac Thermex Thermoanemometer, Model GGA2B, and a Wallac hot-wire air-velocity/temperature-sensing probe,

Model NI-105 (Wallac Oy, Finland). The probe was held at a height of approximately 1.5 m, and was oriented into the wind. The wind direction was estimated and recorded to the nearest compass point ( i . e . , N, NNE,

NE, ENE, E, e tc .), direction being with reference to landmarks whose bearing were known from published maps. This method of estimating direction was only approximate, but was sufficiently accurate for the purpose a t hand, v iz . , to establish the relationship between wind direction and windspeed.

During the 1968-69 fie ld season, a Danforth-White Cup Anemometer,

Model M-50, and Model M-51 Wind Direction Indicator were used. -Both were mounted on an improvised mast with a Model MX-1 si dearm mounting bracket at a height of about 2 m (Plate X). With the wind-direction indicator, the wind direction could be measured to the nearest degree. Windspeed 147 TABLE 10

GLOBAL RADIATION INTENSITY AT

THE QUADRATS^3)

Determined between 1100 and 1300 with a Georgi-type radiometer.

Mean Global Radiation Quadrat Date Intensity, ly-min“'

I 31 X II 68 0.93

I i I 69 0.90

II 12 XII 68 0.99

II 13K XII 68 0.92 I I 14 X II 68 0.91

I l i a 26 I 69 0.84

I l i a . 28 I 69 0.84

Il i a 29 I 69 0.80

I l i a 7 M ' 69 0.75 Illb , 26 XI 68 0.92

IV 12 I 69 0.89

The values represent the mean global radiation intensity measured between 1100 and 1300 h (local apparent time) on cloudless (cover less than 1 okta) days. could be estimated to the nearest 0 .1 m sec” 1 (the scale was graduated

in miles per hour). The advantages of this system were (1) that i t

permitted readings to be made at a constant height, ( 2 ) that data could

be obtained more easily, even during foul weather, and (3) that direction

could be estimated more precisely. The primary disadvantage was that the

cup anemometer was less sensitive than the hot-wire anemometer. When

values obtained with both types of instruments were compared, i t was

found that the hot-wire anemometer gave values that were 2.1 to 2.9 times

those obtained with the cup anemometer. In spite of the large differences

in the values obtained, the data have been used because the purpose of

including data on wind in the study was to determine the direction of the

strongest winds and to correlate this with the distribution of plants.

The absolute values obtained are less important for the present study than they would be for purely meteorological work.

Readings o f windspeed were made by noting the extreme values registered over a 30-second to 2-minute period. The length of each observation was determined by the v a ria b ility of windspeed. The reading was not terminated until the upper and lower values were observed several times. The median value was considered to be the windspeed at the time of the observation. The mean windspeed fo r each quadrat and each direction was based on these median values.

Barometric Pressure. —I t was necessary to determine the barometric pressure every hour because the calculations for relative humidity were based upon temperature and pressure. During both fie ld seasons (1967-

1968 and 1968-1969), a Wallace and Tiernan aneroid barometer, Model

ML-434B/PM (Monmouth Electric Company, Neptuen, New Jersey), was used. 149

The instruments were graduated in m illib ars. They were compared with the

barometers maintained by the United States Navy at McMurdo Station, and

were found to be in close agreement.

Surface Temperatures. —Surface temperatures were measured with

Yellow Springs Instruments surface probes 408 (Yellow Springs Instruments,

Yellow Springs, Ohio). For most observations, a Yellow Springs Tele-

Thermometer, Model 44TE, was used (Plate IX ). For specialized work, such

as that involving comparison of rock and lichen-thallus temperatures,

the Wallac Thermoanemometer and a Wallac NI-103 surface-temperature sensing element were employed also.

Subsurface Temperatures. —Soil subsurface temperatures were measured with Yellow Springs Instruments type 401, 403, or 418 probes, at depths of 20, 11, and 10 cm, respectively. As with most of the other temperature

determinations, a Yellow Springs Tele-Thermometer also was used (Plate IX ).

The probes were placed into holes made by driving long spikes into

the ground with a hammer. After a probe was in place, the soil.was

compacted around the top of the hole so as to keep a ir movement to a minimum. This method was a compromise necessitated by the presence of permafrost, rocks, and boulders in the soil and the fragileness of the probes. Since the probes sensed the temperature at their tips only,

the influence of a ir temperature was probably extremely small.

Soil Moisture

Soil moisture was determined with a Speedy Moisture Tester, Type

D-l or Type G (The Alpha-Lux Company, In c ., Philadelphia and New York)

(Figure 8 ). This instrument utilizes the calcium carbide gas-pressure 150 principle. The water contained in a weighed sample of soil (either a

13- or 26-gram sample, depending upon the amount of moisture) reacts with the calcium carbide in an a ir-tig h t bomb, producing acetylene quantitatively. A pressure gauge, graduated in "per cent wet weight," registers the pressure of the gas. The wet-weight value is converted to a dry-weight basis by means of a conversion table supplied by the manufacturer. According to the manufacturer, tests have shown this method to be very accurate.

The "Speedy" method has the advantages that i t is rapid and simple, and can be carried out in the field on freshly-collected materials, which obviates collecting bulky samples whose moisture contents may change during storage. In addition, the instrument is sturdy, easily trans­ ported, and does not require electric power. Its primary drawback is that it requires the destruction or drastic alteration of the soil sample, which means that samples can be used only once and must be discarded carefully so as not to affect the sampling s ite . I t also leads to the progressive deterioration of a sampling site because each test requires at least 13 g of soil. The continual removal of soil from a s ite probably alters the natural moisture regime. On balance, however, the advantages of the "Speedy" method greatly outweighed its disadvantages. 151

Laboratory Analyses

Plant, soil, and water samples were collected near all of the

quadrats and in th e ir immediate v ic in itie s ; on The Stand Moraine and

The Dailey Islands in McMurdo Sound; and in The Labynith, an area of

deep interconnected canyons near the Upper Wright Glacier. Various

chemical tests were performed on the samples, including microkjeldahl

analysis for nitrogen, electrical conductance, and determination of

selected chemical constituents. Soil samples were collected under or

near plants, in the quadrats, along transects, or randomly. Transects

were usually established along presumed gradients in environmental factors

(salinity, nitrogen content, etc.) or along elevational gradients, the

purpose being to correlate the gradients in the environmental factors

or the elevation with the distribution of plants. While it was usually

possible to quantify the environmental factors, i t was not practical in

most cases to quantify the biomass of plants. This was because plants were d iffic u lt or impossible to collect (e,.£., saxicolous lichens), were

present in extremely small amounts, or were actually hidden by a layer

of gravel (e .£ ., mosses near Quadrat IV ). Thus, the presence or absence

of plants are the parameters that are correlated with the environmental factors. In many cases, the presence of plants was discovered only during the sifting of soil samples preparatory to analysis. It was usually possible to identify the lichens with confidence. The algae were somewhat more d iffic u lt, except for Nostoe. Mosses were usually identified only with d iffic u lty because the harsh environmental conditions had altered th e ir morphology beyond recognition. For this reason, no attempt has been made to give specific identifications to mosses; rather, 152

only the presence or absence of "mosses" was recorded. Fortunately,

in light of this difficulty, there are only three species of moss in

the region: Bryum argenteum, EL antarcticum, and Sarconeurum g laciale.

In most cases, the mosses encountered in this study were probably one

of the two species of Bryum, Sarconeurum being much less common.

P artial Chemical and Physical Analysis of

Plant, S o il, and Mater Samples

No attempt was made to analyze samples completely. Instead, the study concentrated on nitrogen compounds in plant, soil, and water samples, and on the conductance of aqueous soil extracts (including guano) and water samples (including ice). Nitrogen content received special attention because the experimental laboratory studies had indicated that there might be a correlation between plant distribution and the occurrence of nitrogenous compounds in the environment. S alin ity (as reflected in electrical conductance) was studied because the distribution of plants at Cape Royds appeared to have some relationship to salts. Later, i t was found that salinity influenced plant distribution in most of the situations observed.

Other chemical constituents of soils were measured, including phosphorus, which had been considered a possible lim iting element for plants.

Nitrogen.—Nitrogen was measured by a number of techniques. Total nitrogen was estimated by microkjeldahl analysis. This method gave values for reduced nitrogenous compounds (analyses of air-dried control samples indicated that at least 97 per cent of urea nitrogen was 153

detected, for example) and for n itra te (analyses of oven-dried n itrate

control samples indicated that only 65 to 70 per cent of the nitrate

content was detected).

Total Nitrogen. Total nitrogen was determined on dried plant

samples which were ground in a Wiley m ill and passed through a 40-mesh

screen. A temperature of 75 C was used to dry the plant sample for

48 h, both before and a fter grinding. The dried, ground samples were

weighed ( 1 .0 0 0 g) and placed in filte r-p a p e r envelopes made from circles

of Whatman No. 1 f i l t e r paper. The 1-g samples were mixed thoroughly

and placed individually into 800-ml digesting flasks. At least two

control flasks containing no sample (only the f i 1ttr-paper envelopes) and

two blank samples containing neither sample nor envelope were run each

day. In addition, numerous weighed samples of urea and NaN 0 3 were analyzed.

Sifted soil samples were dried at about 45 C (a higher temperature would probably have degraded any urea present in the samples) but were otherwise treated in the same way as the plant samples. Water samples were measured out with pipettes 1n 1-ml aliquots. These, too, were then treated like the plant samples.

To the plant, soil, water, or control samples, one No. 2 Kel-Pak powder (10 g I^SO^ + 0.30 g CuSO^; Matheson S c ie n tific , In c.) and four

Hengar granules were added. Then, 25 ml of concentrated HgSO^ (about

0.098 Nj were added, and the solution was allowed to digest fo r 30 to

35 min, until i t became green in color. The solution then was allowed to cool. In the meantime, 50 ml of a boric acid indicator solution were placed in the receiving flasks. These receiving flasks were placed on the distillation portion of the Kjeldahl apparatus. Water was used

to cool the system below 27 C. When the flasks had cooled, 300 ml of

d is tille d water were added to the remaining liq u id . Seventy m illilite rs

of saturated NaOH were then slowly added down the side of the tilted

Kjeldahl flasks so as to form a double-layered solution. Care was taken

not to shake the flasks a t this point. The glass tube and rubber cork

of the full end of the distillation bulbs were then tightly inserted

into the 800-ml flasks, which were set on the porcelain refractories and

then shaken to mix the contents. The solution was allowed to boil until

slig h tly more than 200 ml had been recovered in the receiving flasks.

The solutions in the receiving flasks were then titrated with the standard

HgSO^ solution. Titration was terminated when the solution changed from green to colorless (slate gray). Then, an additional drop or two of the standard acid solution were added to produce a purple color. During the titration procedure, the solution was stirred constantly. The percentage of nitrogen was calculated according to the equation:

(ml standard acid) (normality of standard acid.) (14) x -joo = per cent 1000 nitrogen.

Before the calculations, the titration value for the control flasks was subtracted from all of the other titration values. In the case of aqueous soil extracts, the values obtained with the equation were doubled to allow for the 2:1 dilution.

Ammonium Nitrogen. Soil samples were extracted with 0.30 N! HC1 fo r

3 or 4 minutes, according to the directions accompanying the Hellige-Truog

Combination Soil Tester (Hellige, Incorporated, Garden City, New York). To make the ammonia test, the extract obtained was mixed with Nessler's solution. I f ammonia was present, a yellow or brown color was produced.

The color produced a fte r 1 minute was compared with the standard ammonia

colors supplied by the manufacturer. In many cases, i t was necessary

to silute the soil solution, several-fold for some soils, to obtain a

color within the range of the chart. Tests were performed in duplicate

or trip lic a te (sometimes more often), the mean determined, and the

resulting values rounded to the nearest 5 pounds of ammonia nitrogen

per acre. To convert to parts per m illion (ppm), the values were

multiplied by 0.285; the resulting values were rounded to the nearest

5 ppm, except fo r values below 5 ppm, which were rounded to the nearest

part per million. The data appeared to be internally consistent; few wide or unexplainable differences occurred within any one area, and

differences in values fo r the various areas were more or less explain­

able.

N itrite Nitrogen. N itrite nitrogen was determined with a Simplex

Soil Test O u tfit (Edwards Laboratory, Norwalk, Ohio). According to the manufacturer's directions, the soil samples were extracted in dilute acetic acid. The color produced upon addition of Lombard's solution, dilute HC1, and d ilu te NaOH was compared with a color chart provided by the manufacturer. The test for nitrite was the only chemical test, other than the Kjeldahl and urea analyses, that did not involve use of the Hellige-Truog kit. N itrite was present in only three samples— in trace amounts in two samples from "Sugar!oaf Ridge" and at a con­ centration of 1 ppm in a sample containing extremely high amounts of ammonia near Quadrat I . Nitrate Nitrogen. The soil samples were extracted in 0.30 N.HC1 for the nitrate test, as for the ammonia test. The resulting extracts 156

of "available" n itra te were mixed simultaneously with Brucine powder and

a 1:2 mixture of 85 per cent orthophosphoric acid and concentrated sulphuric

acid. The resulting pink color was then compared with the standard colors

supplied by the manufacturer. As with the ammonia test, the values were multiplied by 0.285 to obtain parts per million, and rounded.

Urea Nitrogen. Urea nitrogen was estimated with a Urograph K it

(Warner-Chilcott Laboratories Division, General Diagnostics Division,

Morris Plains, New Jersey), modified for use with water and aqueous suspensions of a high-molecular-weight, in ert substance. The Urograph

Kit is designed for determining urea in blood serum, which is much more viscous than water. To increase the viscosity of the test solutions

(water samples and aqueous extracts of guano and s o ils ), 40 g of

Dextran T 40 (M.W. = 40,000) (Pharmacia Fine Chemicals, In c ., Piscataway,

New Market, New Jersey) were added per lite r of sample, giving a relative viscosity of about 2.95. Standard urea solutions of the same viscosity were made up. The Urograph consists essentially of a small piece of chromatography paper containing urease, buffer (KgCOg), and an indicator dye. The test solution rises on the chromatographic s trip , its pH is adjusted by the buffer to the range within which urease can function, and any urea in the sample is hydrolyzed by the urease on the s trip . The solution continues to ascend along the strip, finally coming into contact with the indicator dye; ammonia produced by the hydrolysis of urea raises the pH of the ascending solution and changes the color of the indicator. The amount of s trip along which the color change occurs is proportional to the quantity of ammonia and thus to the amount of urea that was o rig in ally present in the sample. Samples were tested a t 157

ambient room temperature in small test tubes. Because temperature has

an. effect on the te s t, standard urea solutions were employed each time.

To eliminate a ir currents, a small piece of aluminum fo il was placed on

the opening of each tube.

Phosphorus. —The Hellige-Truog test was used to determine the

quantity of "available" phosphorus. The extraction procedure and calcu­

lations were identical to those used for the ammonia and nitrate deter­

minations. . The blue color produced by the reaction of phosphorus with

molybdate (added as ammonium molybdate) and stannous chloride was

compared with the color standard supplied by the manufacturer, the

intensity of the color being proportional to the concentration of

phosphorus.

Potassium. — In the Hellige-Truog test for potassium, potassium is

precipitated by the addition of sodium cobaltinitrite to a mixture of

the soil extract and an alcoholic sodium acetate solution. Precipitation of the potassium leads to turbidity of the solution; as in the other

Hellige-Truog tests, a standard, in this case of known turbidity, is

compared with the test soltuion, the turbidity being proportional to the quantity of potassium in the sample.

Magnesium.—In the Hellige-Truog test for magnesium, the extract is mixed with a solution of Titan yellow dye in methanol; after it has been diluted to volume with distilled water, dilute sodium hydroxide is added. The color produced is compared with the standard colors supplied with the test kit. 158

Calcium. — Calcium was estimated by adding an aqueous sodium

oxalate solution (30 g sodium oxalate in 1 lite r of distilled water)

to the acidic soil extract, allowing the constituents to react, and

then diluting with d is tille d water. Calcium oxalate crystals were formed,

leading to turbidity of the solution. A standard was used to estimate

visually the turbidity of the solution, which was proportional to the

amount o f calcium in the solution. Both the extraction procedure and

the calculations for conversion from pounds per acre to ppm were

identical with those for the other tests performed with the H ellige-

Truog k it.

Hydrogen-Ion Concentration. —The pH of aqueous soil extracts and water samples was determined in the fie ld with a Beckman Pocket pH meter, Model 180 (Beckman Instruments, Inc., Fullerton, California), and

in the laboratory with a Beckman Zeromatic II pH meter.

Sulfate.—The Hellige-Truog test for sulfate was used for only one sample, water collected from the study pond near Quadrat IV. In the sulfate test, a solution of barium acetate is added to the sample; a precipitate (barium sulfate) forms, the quantity of precipitate being proportional to the amount of sulfate in the sample. Since a solution

( I . e . , the water sample) was tested rather than a soil extract, the reading obtained with the standard supplied by the manufacturer was divided by 5 to yield units of parts per million.

Loss on Ig n itio n . —Loss on ignition was employed to estimate the amount of decomposable matter in the soil samples. Oven-dried soil samples were weighed to the nearest tenth milligram, placed in weighed 159 porcelain crucibles, wetted with distilled water, and heated at 315 C fo r 15 h. Then, the crucible and soil sample were reweighed, and the differences betweeen the values before and after the firing were used to calculate the percentage of matter lost during ignition.

Density. —The density of the soil samples was determined by placing 1 ml of oven-dried and sifted soils in'small graduated cylinders and weighing the soils to the nearest milligram. Together with the determinations of loss on ignition, the data on density were used as a rough indication of the quantity of organic matter in the soils.

Soil Color. —The colors of the soil samples were determined, primarily because the color would influence the quantity of solar radiation absorbed and hence probably the temperatures and moisture contents of the microhabitats of plants as w ell. Colors were determined fo r both wet and dry soils with a Munsel Soil Color Notation Chart

(Munsel Color Company, In c ., Baltimore, Maryland). This is the standard method used by soil scientists to characterize the colors of soils.

Conductance.--Soil samples frozen at about -35 C were thawed and dried on benchtops under infrared heat lamps a t 40 to 45 C. This usually took about 6 h. To speed drying, fans were used to force air over the samples. The dried samples were then sifted through standard so ils- analysis sieves to yield a ll fraction of less than 2.00 mm (U. S.

Standard Sieve Series, A.S.T.M. specifications; Tyler Equivalent: 9 mesh).

To 200 g of the dried, sifted soil samples in 1-1 beakers, 400 ml of distilled water were added. The 2:1 water-soil mixture was stirred 160 with a Thomas Magne-Matic S tirre r, Model 15, a t speed 6 for 30 min, and then allowed to s ettle for 15 to 20 min. Conductance was then measured with a Conductivity Bridge, Model RC-16B2 (Industrial Instruments, Inc.,

Cedar Grove, New Jersey), and a conductivity cell with a nominal cell constant of 2.0 cnH. To verify the cell constant, a 0.01 Ji KC1 solution was tested. Calculations based on the data obtained with the

KC1 solution yielded a value of 2.056 cm"l for the cell constant.

Sandstone Study

The fruticose endemic Antarctic lichen Usnea (Neuropogon) antarctica was found to occur on Kar Plateau, but only in one small area on the eastern edge of the plateau, either in a circular deposit of Beacon

Sandstone or on the dolomite immediately downwind of the sandstone (Map X II).

The area of the plateau in which jJ. antarctica was found constituted only

0.125 per cent of the area of the plateau (about 5,000 m2) , and the lichen occupied a maximum area of about 0.25 m^, or about 0.005 per cent, of the d o le rite, less than 6 x 10"® per cent of the total area of the plateau its e lf. The Usnea growing in the sandstone area its e lf was more abundant than on the d o lerite, and was confined mostly to the troughs between small polygonal soil nets.

In most places on the plateau, the dolerite boulders had a very hard and smooth desert varnish that probably inhibited their colonization by the Usnea, but downwind of the sandstone they were covered with a very thin coating of g r it most lik e ly derived from the sandstone. The g r it probably had some effect, either chemical or mechanical, that made the surface of the dolerite boulders more suitable for colonization. 161

A separate study was undertaken to attempt to explain the occurrence

o f the Usnea in the v ic in ity of the sandstone. Soil samples for conduc­

tance measurements were collected along two mutually perpendicular transects

through the sandstone and extending 100 m into the dolerite areas (Figure 8 ).

The transects were oriented parallel (E-W) and perpendicular (N-S) to the

direction of the strongest winds.

In addition, hair hygrographs (including one hygrothermograph),

psychrometers, and telethermometers were set up to determine relative

humidity and temperature values for the sandstone area, and albedo measurements were made with a Georgi-type radiometer.

Results of the Field Studies

Solar Radiation Intensity.—The solar radiation intensity data are

summarized in Figure 9 (in pocket), which is the trace of a Belfort recording pyrheliometer. I t is impossible to use these data to d ifferen tiate characteristics of the insolation regime a t the four quadrats on the basis of absolute radiation intensities, primarily because readings were not made simultaneously. However, some indication of the cloudiness at each quadrat is given by the shapes of the traces. Quadrats I and II appear to have consistently more cloudiness than the other quadrats, especially Quadrat Il lb , which seems to have long periods of more or less clear skies. Quadrat IV was re la tiv e ly cloudy, but usually during discrete periods of times (when low stratus clouds from o ff the Ross Ice

Shelf and Koettlitz Glacier moved inland into the valley area).

The traces indicate that radiation intensity was high, especially near the summer solstice, often approaching the theoretical maximum value of 1 .0 lymin"^ (the peaks in the trace that exceed 1 .0 ly*min“l are Figure 8 . The approximate locations (dots) at which soil samples were collected along the two perpendicular transects through the center of the sandstone deposit on Kar Plateau. The conductivity measurements are presented in Graph VI. 5-: 164

Graph V I. Ranges of conductance values obtained with 2:1 aqueous extracts of soil samples collected on Ross Island and in the McMurdo Sound region of southern Victoria Land. The solid black circles indicate the mean value of the soils in each category. The arrows to the right of the line for lichen point to values obtained when one sample, in which lichens were present in extremely small amounts epiphytically on a moss, was eliminated from the calculation. |------1------1------!------» ... —i—:------1------!------H ----- ALL NO PLANTS PENGUINSKUARY LICHENS MOSSES PRASjOLA BLUE- SOILS PLANTS GUANO SOILS ALGAE 166

undoubtedly due to an "over-response" by the instrument when f ir s t exposed

to bright sunlight).

Table 10 presents global (!•£ .» sun plus sky) radiation values

obtained at a ll fiv e of the quadrats on various dates with a Georgi-type

radiometer. The measurements were made on cloudless days (when cloud

cover was 1 okta or less) between 1100 and 1300 h. The data indicate

that values do indeed approach 1.0 lymin"^ (£•£•> Quadrat I I on

12 December 1968). The data also indicate that the intensity of sunlight

is directly dependent upon the time of the year--i_.e., on proximity to

the summer solstice. This relationship was to be expected. A consequence of this relationship is that the temperature data (and probably other data) must be interpreted with caution because the intensity of sunlight

impinging upon a surface determines the temperature to which i t can rise .

Soil Moisture

The results of the soil-moisture determinations are presented in

Graphs V I I - X I I I , arranged according to quadrat.

Quadrat I .--Figure 9 is an aerial photograph of Quadrat I . Sites

RM 1 through RM 5 are indicated by the large white asterisks (1-5).

Sites Royds 1-a through Royds 4-a are indicated by the encircled numbers

(1 -4 ), and Sites Royds 1-b through 7-b are indicated by the numbered white circles (1-7). Graph VII presents the results of soil-moisture determinations a t Sites RM 1 through RM 5 from 26 or 27 to 29 December

1968.

Quadrat I I . —The soil-moisture data obtained at Quadrat I I during the 1967-1968 and 1968-1969 seasons are presented in Graphs V III through X.

In Graph V III,th e data obtained at six sites on 9 January 1968 are 167

Figure 9. Soil-moisture sites in and near Quadrat I . The large white numbers and asterisks indicate soil-moisture sites RM1-RM5. The other numbers indicate miscellaneous sites sampled at other times. i Qart fo 2 Dcme 16 truh 9 December 29 1968. December through 26 1968 from I Quadrat in j Gah I Si-osue otns t ie R 1 through RM 1 RM 5 Sites at contents Soil-moisture II. V Graph !

SOIL MOISTURE, QUADRAT I (CAPE ROYDS, ROSS ISLAND) HJM A 1H9J3M o M* m co . y f m Q O 1H30J3J JO HQ yiI1I 0S I0 1 3yniSI01AI 9 0 N 1 3 N 1 ‘ r < k > cm — in' CM 10 co CM 10 CO CM CO CM ’ * CM O -- O° M i. L CM M < CM 8 CM CM t- i U L C LU

170

Graph V III. Soil-moisture contents of Sites CM 1 through CM 6 in and near Quadrat I I a t various times on 9 January 1968. The locations of all of the soil-moisture sites are shown on the small diagram of Quadrat I I accompanying the graph. SOIL MOISTURE CONTENT, PERCENT OF DRY WEIGHT 10-’ 0 00 40 2 i OL MOISTURE, QUADRAT SOIL I9 .68 IE F A (OA APRN TM) h TIME), APPARENT (LOCAL DAY OF TIME SNOW 14.5m A 20 80 0 0 4 2 1800 1200 0 0 6 0 + U CP COIR RS ISLAND) ROSS CROZIER, (CAPE + CM 3 + 4 - A A — SITE CM 5 CM —SITE A IE M4 CM —B SITE □ - S IT E CM 3 CM E IT S - □ I CM SITE O— —ST CM2 M C SITE ©— - IE M6 CM SITE

172

Graph IX. Soil-moisture contents at Sites CM 1 through CM 3 and at Site CM 6 in and near Quadrat I I at various times from 20 to 23 January 1968. The locations of all soil-moisture sites are shown on the small diagram of Quadrat I I accompanying the graph. (There are no values for Sites CM 4 and CM 5.) 2400 SOIL MOISTURE CONTENT, PERCENT OF DRY WEIGHT 2 6 8 " -- -- OL MOISTURE,QUADRAT SOIL 201.68 20 2400 1200 IE F A (OA APRN TIME),h APPARENT DAY (LOCAL OF TIME 21 1.68 1200 U 2400 CP COIR RS ISLAND) ROSS CROZIER, (CAPE 221.68 1200 CM 3 - a - CM2 CM I CM 5 CM4 CM 6 2400

231.68 1200 SNOW 14.5m 2400 rp X Si-osue otn a St C 5 n uda II fo 1 t 1 December 15 1968. to 11 from I I Quadrat in CM 5 Site at content Soil-moisture Graph X. SOIL MOISTURE CONTENT, PERCENT OF DRY WEIGHT 2400 8 + 2 3-- 5-- - 20 2400 1200 OL OSUE QART I CP COIR OS ISLAND) CROZIER,ROSS (CAPE II QUADRAT MOISTURE, SOIL IE F A LCL PAET IE, h APPARENT DAY TIME), (LOCAL OF TIME 20 40 20 40 20 2400 1200 2400 1200 2400 1200 SITE CM 5 CM SITE 15 68 Zn. 20 2400 1200 175

Graph XI. Soil moisture at three sites in Quadrat Ilia on 6 and 7 January 1968. Site KM 1 (open circles) was occupied by the macroscopic blue-green alga, Nostoc sp. Site KM 2 was not associated with macroscopic plant growth. S ite KM 3 was near soil lichens, but was not vegetated. TEMPERATURE AT SURFACE OF SOIL, C SOIL MOISTURE CONTENT,PERCENT OF DRY 5 0 ’SURFACE TEMPERATURE C20’ .QUADRAT a IH KAR PLATEAU (UPPER)] 10 |0.. - 5 " 5 1800 + OL OSUEQART KR LTA (UPPER)] PLATEAU C KAR o m MOISTURE,QUADRAT SOIL 6 6

1.68 1.68 24001800 2400 1.68 7 68 .6 1 7 IE F A (OA APPARENT TIME),h DAY (LOCAL OF TIME IE A (OA APRN TM) h APPARENT DAY TIME), (LOCAL TIME 0600 0600 1200 1200 KT 2 KT KM2 I KM KM3 1500 1500 the model used in a ll other determinations could be read to the nearest nearest the to read be could determinations other ll a in used model the ntuet sd n hs mitE dtriain cud e ed ny o h naet . pr cent; per 0.5 nearest the to only read be could determinations moistuEe these in used instrument SOIL MOISTURE CONTENT, PERCENT OF DRY WEIGHT 0.5 ■■ 0.5 2 1.5 ■ ■ 1 . . 0 0 1200 • - * * * rp XI. ol osue t uda Il rm 1 o 5 oebr 98 Te oe o the of model The November 25 1968. to 21 from Illb Quadrat at moisture Soil II. Graph X OL OSUE.UDA mb (A PAEU ITRA LAND) VICTORIA PLATEAU, (KAR b m MOISTURE.QUADRAT SOIL 2400 22X1.68 1200 IE F DAY OF (LOCAL APPARENT TIME TIME),h 40 1200 2400 23X1.68 2400 24X1.68 .1 0 e cent. per 2400 25X1.68 12001200

w pros f h 16999 uta sme^ aus xedd per 1 summer^ exceeded Values 196891969 austral the of periods two et 3 n 4 eebr 98 ol afer rlne sofl. - snowfall. prolonged r fte a only December 1968) 4 and (3 cent

MOISTURE CONTENT OF SOIL, PERCENT OF DRY WEIGHT 5-• - .5 0 5-- .5 0 0-- .0 5 0.5-- VISIBLE M ■ , o CLOUDY © 1 0 3 1 i .o - - - .o i 1 .+ SNOW X 1.5+ . . rp XII Mitr cnet o sis n uda I during IV Quadrat in soils of contents Moisture III. Graph X 4 0 240 4020 10 2400 1200 2400 2400 0 0 2400 3 -. K THROUGI * * * * * * ® -• + OL MOISTURE,QUADRAT SOIL 12 - • - - S I T E 2 E T I S - - • - I 2a . 68 2a I - oST 1 —o—SITE ©0®OQ®OOOO ©©€>©

1200 1200 1200 © © O O O O O O O 0 © O O O O O O O O O O O - O g > g © O

IE F A (OA APPARENT TIME (LOCAL ),h DAY OF TIME 2400 2400

.68 u X 2 12 1.69 1200 1200 ( ers r ie m 2400 2400

J. J. y e l l a v © © * F * F # © F * F F * © © © © 13 I. 69 I. 13 U.68 3 XU 71.69 1

a e r a 202400 1200 2020 1200 2400 1200 1200 . n r e h t u o s 2400

4 69 .6 1 14 4 xn.68 4 8 . 9 18 1.6 ctoria r o t ic v 0 1200

d n a l

)

2400 0 240 00 40 2 178 179

presented. The small diagram on the graph indicates the locations of

the sites with respect to snow and each other. Graph IX presents data

obtained at the same sites (with the exception of Sites CM 4 and CM 5)

from 20 to 23 January 1968. The third of this series of graphs, Graph

indicates the values obtained at Site CM 5 from 11 to 15 December 1968.

Quadrat I l i a . —Plate X consists of two views of Site KM 3 in

Quadrat Il ia early in the season (A) and later in the season (B). Soil was collected about 0.9 m from the edge of plant growth, which is located

in the foreground of Plate X A, and ju s t out o f the photograph in Plate

X b. Mosses, lichens, and algae occur on the soil near the center of each photograph. In Plate X B, a hair hygrograph and subsurface-temper- ature probe are clearly visib le. The soil-moisture contents determined on 6 and 7 January 1968 at Site KM 3 are plotted in Graph X I; in addition, both surface-temperature and soil-moisture data obtained at

Sites KM 1 and KM 2 (both in Quadrat I l ia ) are plotted in the graph.

Quadrat I I I b .--The moisture content of soil at one s ite in Quadrat

I I l b was determined from 21 to 25 November 1968. The data are plotted in Graph X II.

Quadrat IV . —Moisture was measured at three sites in Quadrat IV,

Sites MM 1, MM 2, and MM 3 from 1 to 4 December 1968 and on 11 January

1969. Moisture was also determined a t one site (MM 1) from 12 through

18 January 1969. The results are plotted in Graph X III (in the graph the sites are referred to only as Sites 1, 2, and 3). Also shown on the graph are the weather conditions noted a t each reading.

Relationship Between Soil Moisture and the Growth of Plants.—

Much of the data plotted in Graphs VII through X III, plus additional 180

Plate X. Photographs of an area of a lg a l, lichen, and moss growth in Quadrat I l i a . Early in the summer, snow remains in the protected area formed by two rocks (A), and the soil remains re la tiv e ly moist during the rest of the season a fter the snow has melted (B). The tape measure in (B) is extended to a length of 1 m. 181

.VJ® 182 data are tabulated in Table 11 , the object being to indicate the relationship between plant growth and soil moisture.

The soil-moisture data are not easily interpreted. As Graph VII indicates, the moisture content of soil at Site RM 1 was consistently below 1 per cent, yet lichens and mosses grew there; on the other hand, moisture at Site RM 2 was usually greater than 5 per cent, and almost always greater than 6 per cent, yet neither lichens nor mosses grew there. The lack of lichens at Site RM 2 is explained by its very high concentrations of water-soluble salts. The occurrence of lichens and mosses at Site RM 1 is most easily attributed to the fact that snow accumulated there temporarily a fte r snow storms. The soil-moisture content at Site RM 3 v/as greater than 1 per cent on a ll but the f ir s t and fif t h occasions. The presence of lichens and mosses at Site RM 3 is attributable partly to sufficient moisture and partly to a presumed lower salinity. On the other hand, while the moisture content of the soil a t Site RM 4 was s u ffic ie n t fo r the growth of both mosses and lichens, plants were absent there (except fo r occasional subsurface mosses) because the s a lin ity was somewhat greater than the level that mosses could withstand.

All soil-moisture values were well above 1 per cent in Quadrat I I .

The consistently high moisture contents account for the prevalence of

Prasiola crispa, as does the presence of numerous skuas, which continually excreted uric acid.

Soil-moisture values at Quadrat Ilia were much higher than the values obtained a t Quadrat Illb . Soils in Quadrat I l i a contained from

1 to nearly 10 per cent moisture, while the soils in Quadrat IIlb TABLE 11

MOISTURE CONTENTS OF SOILS IN RELATION TO THE OCCURRENCE OF PLANTS

Moisture Content of Soil, per cent of dry weight* ______Sample or Site Locality C ollectio n Data D etails and Remarks Plants Present Plants Absent Date Time, h

Cape Royds Area. Ross Island

Royds 1-a Quadrat I 3.5 2 I I 68 1600 In area of lichen growth. Snow had fallen on previous day, but was almost completely gone at time of observation.

RoydS 2-a D itto 10.0(b) D itto Ditto In low area near center of Quadrat. Royds 3-a Hear 8.7(b) ” Upwind of knoll, 3.5 m S of Quadrat. Quadrat I

Royds 4-a D itto : 6.5(b) " Upwind o f k n o ll, 11.3 m S o f Quadrat.

Royds 5-a 5.9. 1715 Soil on top of large knoll 30 m S of Quadrat.

Royds 6-a 10.2 1730 Soil on top of large knoll 30 m S of Quadrat, under and near Praslola crispa.

Royds 7-a 8.2 1745 S oil on top of large k n o ll 30 m S o f Quadrat, near Site Royds 5-a.

Royds 8-a 6.6 1800 Visibly moist soil on to? of knoll 30 m S of Quadrat, near Site Royds 6-a.

Royds 9-a 7.4 1815 Soil on top of knoll 30 m S of Quadrat, ca. 0.5 m from both Site Royds 6-a and S ite Royds 8-a.

RM 1 Quadrat I 0.7 (0.5, 1.0) 26-29 XII 68 Dry s o il near W boundary o f Quadrat. N « 28.

RM 2 D itto 6.9 (4.5, 8.6)(5) Ditto Very moist s o il near E boundary o f Quadrat. N * 28.

RM 3 2.7 (0.9, 3.8) 27-29 X II 68 Among abundant lichens and mosses. S oil m oist. £ * 11.

RM 4 3.2 (2.0, 4.4) D itto Among scattered mosses in center of Quadrat. S oil m oist. N_« 11.

RM 5 1.5 (1.0, 2.2)(5) Dry soil in lee of knoll. N^* 11.

03 CO TABLE 11.—(continued)

Sample or Site Locality . . Moisture Content of Soil, per cent of dry weight^) Collection Data Details and Remarks Plants P r e s e n t ' Plants Absent Datenme,.h

Cape Royds Area, Ross Island (continued)

Royds 1-b quadrat I • 0.6 2 I 68 Near Sites RM 1 and RH 2.

Royds 2-b Ditto • 0.8 . Ditto1 On small knoll in HU corner of Quadrat.

Royds 3-b “ ' 1.1 M On drained, upwind slope.

Royds 4-b II 1 9 . 8 ^ U In depression near S£ corner of Quadrat

Royds 5-b H 6.2 . . • . . H In low area E of d rift. Widely scat­ tered mosses. Near S ites RM 4 and Royds 2-a.

U . Royds 6-b Hear 1.4 On top of knoll, outside Quatrat. Quadrat ! n Royds 7-b Quadrat I 2.9 Mosses and lichens. Near S ite RM 3.

Royds OE Hear 17.3 5 I 69 1212-1243 Transect perpendicular to s n w d r ift. Quadrat I Moss present.

P.oyds IE D itto 10.5 Ditto Ditto D itto H * . U H Royds 2E N 11.0 H H n Royds 3E N 8.9 U U Royds 4E H 9.9 Transect perpendicular to snowdrift. No moss.

Royds 5E II 4.2 H 0 Transect perpendicular to d rift. Moss absent. — N N Royds 6E M 5.5 D itto

Royds OH K 7.4 1346-1430 Transect perpendicular to d r if t . Moss present.

Royds 1U N 7.9 " Ditto Ditto M H H Royds 2W N 5.7

h n N Royds 3H ■ 7.5 H I* Royds 4H M 4.5 Transect perpendicular to d rift. Moss absent.

M U Royds 5W « 3.4 D itto TABLE H .—(continued)

SWI. „r Si„ . M g . f e . y ‘ °f ».S’ UCt' ° \ a -C

Williamson Rock Area. Ross Island^)

01 1 Quadrat I I 6.9 (4.9, 10.3) 9 I 68 0900-1800 At VI boundary of Quadrat, 3 m from snow. N * 4.

CM 1 D itto 5.1 (4 .5 , 6.0) • 20-23 1 68 A t W boundary o f Quadrat, 3 n from snow. N » 12.

CM 2 W 6.9 (5.3, 9.6) 9 I 68 . 0900-1800 At N boundary o f Quadrat, 7 m from ■ snow. J l = 4.

CM 2 M 4.8 (4.0, 6.6) 20-23 I 68 A t N boundary o f Quadrat, 7 m from snow. = 11.

01 3 H 6.5 (5.1, 7.6) ; 9 I 68 1200, 1500 Near Su boundary o f Quadrat, a t edge o f snow. H » 3.

CM 3 M 5.5 (4.4, 7.4) ... 20-23 I 68 Near SW boundary o f Quadrat, a t edge o f snow, ji ■= 7.

01 4 t l 8.4 (7 .4 , 9.4) 9 I 68 1200, 1500 Center o f Quadrat a t edge of snow. N = 2.

CM 5 U 7.9 (7.6, 8.1) 9 I 68 1200-1300, Near NE boundary o f Quadrat, a t edge 150Q o f snow. N = 2.

CM 5 II 3.7 (2 .1 , 6.3) 11-15 X II 68 Near NE boundary o f Quadrat, a t edge o f snow, jl ■ 29.

CM 6 Hear 6.3 (5.9, 6.3) 9 I 68 1200, 1500 Top of "Sugarloaf Ridge," 24 m from Quadrat I snow. N. = 2.

01 6 D itto 4.5 (3.8, 5.0) 20-23 I 68 Top o f “ Sugarloaf Ridge," 24 m from snow, t) ■ 5.

Crozier Is Hear 4.7 21 I 68 Afternoon Near Prasiola crispa . Quadrat I

C rozier lb D itto 5.8 D itto D itto Under P. c ris n a . near S ite C rozier la .

C rozier 2s M 4.4 M II Near P. crispa.

M M C rozier 2b 11.7 M Under P. c ris n a . near S ite Cro 2ie r 2a.

Crozier 3s II 6.4 IIM Near P. crisoa .

« IIU C rozier 3b 4.9 Under P. c ris o a . near S ite C rozier 3a. TABLE 11 .-(c o n tin u e d )

Moisture Content of Soil, per cent of dry weight^3) Collection Data Sample or Site Locality Plants Present Plants Absent bate rime, h D etails and Remarks

Kar Plateau. Granite Harbor Area

Kar A1 quadrat Ilia 11.2 I 1968 Hear Hostoc.

Kar A2 Sear 11.0 D itto Under and near moss. Quadrat I l i a

KM 1 Quadrat I l i a 4.10.8, 8.0) 6 & ? I 1968 0.5 m from small snowdrift. No plants. N ■ 7.

KM la D itto 11.2 7168 1030-1100 Near KM 1, next to Hostoc.

KM B -l 1.2 (0.5, 1.6) 21-25 XI 68 Shallow s o il. E arly in season, ti » 30.

KM 2 7.3 (5.0, 9.4) 6 4 7 168 Near boulders and about 0.5 m from small patch o f snow. » 6.

KM 2 8.3 7 I 68 1030-1100 D itto

KM 2a 11.7 D itto D itto Under Hostoc. 4 m from S ite KM 4.

KM'3 2.5 (1.2, 5.2) 6 & 7 I 68 0.9 m from edge of lichens growing on s o il. N = 6.

KM 3 3.0 (2.7, 3.3) 7 I 68 1030-1100 0.9 m from edge of lichens growing on s o il. N = 3.

KM 3a 8.2 (7.5, 8.8) Ditto Ditto In corner formed by large rocks, a few cm from soil lichens. N « 2. 5.8 KM 3a I 68 D itto

KM 3b 9.8 7 I 68 1030-1100 Under lichen s, moss, and alga in protected area (between Sites KM 3 and KM 3a).

KM 3b 10.3 (10.1, 10.4) D itto D itto Under lichen s, moss, and alga in protected area (between Sites KM 3 and KM 3a). N = 2.

Kar 81 Quadrat I llb 1.0 22 XI 68 1020 S oil net. No plan ts. E arly in season.

Kar B2 D itto 1.6 Ditto 1025 Soil net. Near moss and lichens. E arly in season.

Kar 83 Sandstone deposit 3.2 “ 1045 S o il. Usnea (Neuronooon) an tarctica near Point Retreat abundant in areal Early in season.

00Ol TABLE 11 . — (continued)

Sample o r S ite L o c a lity . Moisture Content of Soil, per cent of dry weiqht^3) Collection Oata D etails and Remarks Plants Present Plants Absent Date lim e, h

Miers Valley Area, Southern Victoria Land

MM 1 Quadrat IV 0.6 (0.3, 5.2) 1-4 XII 68; Shallow soil. No plants. N_ « 7S. 11-18 169 m 2 D itto 0.6 (0.3, 1.2) 1-4 XII 68;' Shallow soil. No plants. • 16. 11 I 69 N KM 3 .0.7 (0.3, 2.7) Ditto O itto

^D ete rm ine d w ith a "Speedy Moisture T e ster," Type D-l o r Type G (Alpha-Lux Company, In c ., P hiladelphia, Penn.). f i >Saline soil. ^ A U of the moisture values for the Willimson Rock area are tabulated under the'category "Plants Present" because lichens and P. crisoa were widely scattered everywhere moisture samples were collected. A ll of the moisture determinations were thus made with soils collected near plant growth, but not necessarily in close association with plants. At the other locations, plants occurred at more discrete locations.

00 188

contained only 1 to 1.5 per cent moisture. The fact that vegetation was more prevalent on the lower portion of Kar Plateau is probably explained by the fact that birds were more common there than at the central part of the plateau in the v ic in ity of Quadrat I l i a , since skuas from the nearby skuary used the adjacent pond for bathing. S alinity was not significantly different in the two areas.

Table 11 indicates that the moisture content of soils under plants was usually sig n ificantly higher than that of soils devoid of plants, although wet saline soils such as those in Quadrat I were devoid of plants, and the false impression is given that moisture is less s ig n ifi­ cant than i t really is . The situation in Quadrat I indicates that, despite the high amounts of soil moisture, plants were prevented from growing because of the saline conditions.

The data on soil-moisture indicate thatmois.t plants are associated with the moister soils, but not with saline soils. Table 12 shows that algae (Prasiola crispa and Nostoc sp.) tend to grow in the moistest locations. As Graph VI showed, however, they are also associated with more saline soils than either mosses or lichens. The indication is, then, that macroscopic algae inhabit the wettest and highly saline locations, while mosses and lichens inhabit less moist and the least saline habitats.

Plate XI shows that there may be a cyclic cause-and-effect relationship between soil-moisture and the occurrence of macroscopic plants. Apparently, the snow seen in the plate has remained on the moss and alga because the plants are cooler than the surrounding terrain ; this difference in temperature may be due to greater absorption of 189 TABLE 12

MOISTURE CONTENTS OF SOILS COLLECTED UNDER AND NEAR MACROSCOPIC ALGAE GROWING NEAR QUADRATS I , I I , AND I l i a

Paired samples collected as close together as possible.

Moisture Content, Locality Sample(s) Date(s) per cent of dry weight Under Alga Near Alga

Prasiola crispa

Royds Royds 6-a 2 I I 68 10.2 (N=l) 6 .6 (N=l)

Crozier Crozier la- 21 I 68 7.2 (N=3) 5.2 (N=3) 3b

Nostoc sp.

Kar Kar A1 I 1968 n . 2 ^ )(N = l) ------

Kar KM1 and 6 and 7 11.2(a)(N=l) 4.1 (N=7) KMla I 1968

Kar KM2 and Ditto 11.7 (N=l) 7.5 (N=7) KM2a

^ N e x t to, but not under, the Nostoc. 190

Plate XI. The photographs of mosses (A) and algae (B) near Capes Royds and Crozier, respectively, showing that these plants may increase the moisture and lower the temperature of the soil micro­ habitat beneath them by intercepting the flow of heat. The alga in (B) is Prasiola crispa. In both photographs, which were taken shortly after light snowfalls, snow remains on the plants but not on the surrounding, unvegetated s o il. Apparently, the plant cover intercepts the passage of heat from the soil and, i f so, probably reduces the flow of solar energy from above into the soil. The persistent snow cover would enhance the la tte r effect in the same way th at the large snowdrifts a t Cape Royds induce cooler and moister conditions nearby. It is likely that the active layer is shallower and the soil salinity lower under such plants. A successionary progression from macroscopic green or blue-green algae to mosses and then to lichens may occur in the most saline areas, the predecessor plants creating less saline conditions that are more suitable for succeeding plants. Such a sequence was suggested by superficial observations, but the question of its occurrence was not studied c r itic a lly .

192

sunlight by the soils or to a reduction of heat transfer upward from

the soil by the insulating cover of plants. The presence of the plants

probably leads to a lower temperature in the soil and to a lowered

evaporation rate, thus increasing the moisture content of the soil.

Thus, the correlation between high moisture and, fo r example, macroscopic

te rre s tria l algae, must be considered a consequence of both the moister

conditions and of the presence of the plants.

Results of the Laboratory Analyses

Physical and Chemical Characteristics of Soil s.--Most of the data

obtained on the physical and chemical properties of the soils collected

during the 1967-1968 fie ld season are presented in Table 13.

Soils at Cape Royds tended to be very dark gray or black (a ll were

black when w et), while those in the v ic in ity of Quadrat I I were somewhat

lig h te r. On Kar Plateau, soils were grayish brown; soils from "Miers

Ridge" were olive in color.

The densities of most of the soils were high, the densest being

that of a soil from The Labyrinth, a completely mineral soil. The

least dense soil was from a knoll near Quadrat I on which Prasiola was abundant; when the soil was collected i t was noted that the sample had a humus-like appearance. The loss, of mass that occurred when the soil samples were heated was roughly inversely proportional to the density, an indication that the data are valid and that the density was a function of the content of organic matter. Together, the loss on ignition and density data are useful for interpreting the information on nitrogen content, since organic matter will contain nitrogen. This TABLE 13

PARTIAL ANALYSIS OF SOME SOIL SAMPLES FROM ROSS ISLAND AND VICTORIA LAND

Concentration, part per m illion (1061^0 Loss on Kunsell-Color Notation Description of Ammonium m tra te N itr ite Ca Ig n itio n , Density, Collection Site Dry Wet N N N T°$ ) per cent g-cm'3

Cape Royds. Ross Island

Hear Backdoor Bay 5 Y 4/1 (dark gray); 10 YR 2/1 15 0-T 0 70 115 315 N.O. 215 0.339 1.58 (r.o lichens o r 2.5 Y 2/0 (black) (black)\ u lo u iw y a mosses} (N=2) 2.5Y 2/0 (black)

“T ra n sitio n Zone,“ 5 Y 4/1 (dark 10 YR 2/1 20 70' 85 855 N.D. 255 0.334 1.45 next to lichens gray) (black) and mosses and near Prasiola (N“ D .

Quadrat I

Middle o f 5 Y 3/1 (very 5 YR 2/1 (black) 20 ' 70 180' 545 N.D. 400 0:738' 1.53 quadrat (scattered dark gray) abundant lichens and mosses 1n vicinity) (IM ).

Edge of quadrat 5 Y 3/2 (dark 5 Y 2/1 (black) 10 340 230 285 145' 855 0.590 1.50 (scattered abun­ olive gray) to dant lichens and 5 Y 2/2 (black) mosses in vicinity) (N“l). Edge of quadrat, 5 Y 3/1 (very 2.5 Y N 2/0 10 70 135 855 N.D. 215 0.518 1.53 no plants (N.*l). dark gray) to (black) 5 Y 2/1 (black)

Edge of study 5 Y 3/1 (very 5 Y 2/1 (black) 20 210 170 345 N.D. 230 0.475 1.51 ocnd near quadrat. dark gray) to Blue-green algae 5 Y 2/1 (black) abundant (H.*l).

Knoll 30 m SU of quadrat

Under and around 2.5 Y 5/2 (grayish 10 YR 2/1 (black); 65 0 1000 1165 4903 265 0.897 1.42 Prasiola (N.*2). brown); 10 YR 2/5 Y 2/2 (very (Moisture: 9.3 5/3 (brown) dark grayish per cent) brown)

Near but not associ­ 2.5 Y 4/2 (dark 5 Y 2/1 (black); 115 93 0-T 480 153 3815 106 1680 0.736 1.40 ated with Prasiola. grayish brown); 5 Y 2/1 (black) N*2. (M oisture: 10 YR 4/1 (dark 7.3 per cent.) gray) lO CO TABLE 13.—(continued)

Concentration, part per m illion (lQ6)(a) Loss an Description of Hunsell Color Notation Ammonium N itra te N itr ite Tot. Kg Ca Ig n itio n , Density, Collection Site ' Dry Wet N NN SI) per cent g-cm"3

Cape Royds. Ross Island (continued)

Knoll 30 n SW of Quadrat (continued)

Hear P rasiola. 2.5 Y 4/2 (dark 10 YR 2/1 20,475 5 fca. 0.3 373fl( ) 10,000 4570 ' 1055 3455 2.075 1.10 Poorly drained. grayish brown) (black) Appear ta in humus. H«l. (Moisture: 678 per cen t.)

Williamson P.ock Region. Ross Island.

Slope o f "North 5 Y 4/1 (dark 10 YR 3/1 (very 170 20 890 685 285 N.D. 1570 1.050 1.55 H i l l , ” near pen­ gray) dark gray) to guin rcokery. 10 YR 2/1 Prasiola present. (black) ----- “Sugarloaf Ridge,” 30 0-T 902 291 276 N.D. 292 0.658 1.56 in skuary (includ­ ing Quadrat I I ) . Footnote (c) Footnote (d) N=5. Lichens and Prasiola scattered. (pH« 4.32-5.13.)

"Bryant" ("Pat's Peak"), in skuary.

N slope. N»l. 2.5 Y 4/2 (dark 10 YR 2/1 35 35 10 1545 1.760 1.20 Lichens an

Summi t . N fl. 10 YR 3/2 (very 10 YR 2/2 115 Trace 210 315 »1 8 5 N.D. 1430 0.537 1.41 Lichens and dark grayish (very dark Prasiola occa­ brown) brown) sional to com­ mon.

Kar Plateau

Hear Quadrat I l i a , 2.5 Y 5/2 (gray­ !.5 YR 3/2 15 0 0 115 285 N.D. 1680 0.612 1.50 under moss. N«l. ish brown) to (very dark (Koisture: lT.O 2.5 Y 4/2 (dark grayish per c e n t.) grayish brown) brown) TABLE 13.--(continued)

Description of Munsell Color Notation Concentration, oart oer million (106)^ ) Loss on Collection Site Dry Wet Ammonium Nitrate Nitrite lotai, P K Mg Ca Ig n itio n , Density, N N N N' ) per cent g«cm"J

Miers Valley Reqion hear Lake Miers. 5 Y 5/2 (olive 5 Y 3/2 (dark 3 Trace 0 440 10 255 345 3715 1.217 1.30 Algal crust. (1=1. gray) to o liv e gray 5 Y 4/2 (olive gray)

5 w all o f v a lle y . 5 Y 4/2 (olive 5 Y 3/1 (very Under lichen . N_»l. gray) dark gray) • 5 Trace' 0 210 4 545 70 6000 0.815 1.48

5 w all o f v a lle y . 5 Y 4/3 (olive) 5 Y 3/1 (very 10 0 0 690- 35 130 N.D. 2485 0.560 1.49 On rock. Uncer ■ dark gray) to moss. J M . 5 Y 3/2 (dark olive gray)

Top of "Miers Ridge," 5 Y 4/2 (o liv e 5 Y 3/2 (dark 20 0 0 — : 45 25 55 2630 0.392 1.63 near Quadrat IV. gray) olive gray) Under lichens. 11*1.

Top of "Miers Ridge," 5 Y 5/3 (olive) 2.5 Y 3/2 (very 15 0 0 70 35 165 N.D. 1145 0.275 1.55 near Quadrat IV. dark grayish N=1. brown)

Top of "Miers Ridge," 5 Y 4/2 (o liv e 5 Y 3/1 (very 5 3 0 340 Trace 255 2085 6000 0.602 - 1.36 in and near study gray) dark gray) pond. Blue-green algae abundant. H«l.

The Labyrinth

Various sites. 11=5." 7 >25 0 170 - 15 62 880 292 . 0.202 . 1.72 , (conductance: ~1230 (10-270) (255- (0-715) pmho a t 25 C (11=1). . Footnote (e) Footnote (f) 3145) pH = 9.13. H=l.

^Determined with a Hellige-Truog Soil Testing K it, except for the n itrite concentrations, which were determined with an Edwards Soil-Testing Kit. The values given are the means o f several determinations on each sample, and are rounded. (b)"Total H" was determined on sifted soil samples, while ammonium, nitrate, and n itrite nitrogen were determined on extracts.

| c|7.5 YR 5/2 (brown); 5 YR 4/1 (dark gray); 2.5 YR 3/2 (dusky red); 5 YR 3/1 (very dark grayO; 5 YR (dark reddish brown). 5 YR 3/2 (dark reddish brwon) to 5 YR 2/2 (dark reddish brown); 2.5 YR 3/2 (dusky red) to 2.5 YR 2/2 (very dusky red); 2.5 YR 2/4 (dark reddish brown); 2.5 YR 2/2 (very dusky red); 2.5 YR 2/2 (very dusky red). ^ 1 0 YR 3/2 (very dark grayish brown); 10 YR 3/2 (very dark grayish brown) to 10 YR 3/3 (dark brown); 10 YR 2/2 (very dark brown); 10 YR 5/3 (brown); 10 YR 5/3 (brown) to 10 YR 4/3 (brown to dark brown) (f )l0 YR 2/1 (black); 10 YR 3/2 (very dark grayish brown); 10 YR 2/2 (very dark brown); 10 YR 3/2 (very dark grayish brown); 2.5 Y 3/2 (very dark qravish brown). admittedly circumstantial evidence explains in part the very high

quantity of nitrogen in the organic soil collected near Prasiola on

the knoll near Quadrat I , and indicates that the high values of nitrogen

found in soils on "Sugarloaf Ridge" are largely inorganic. The

surprisingly high value for total nitrogen in the sample of mineral soil from The Labyrinth probably is due completely to n itra te ; the very small loss on ignition and the high density support the inference that organic matter did not account fo r the nitrogen. The high pH of the sample (9.13) explains in part the low value for ammonium nitrogen

(ammonia would v o la tiliz e at such a high pH). The dry conditions would permit nitrates, which are very soluble in water, to accumulate, and would also explain the salinity and absence of vegetation in The

Labyrinth.

Phosphorus was present in all samples analyzed; the lowest value was obtained in a sample from the study pond near Quadrat IV, in which blue-green algae were abundant. The low value indicates that lack of phosphorus may have been a lim iting factor in the growth of the alga.

The next lowest value (4 ppm) was obtained with a sample from the wall of Miers Valley. This soil was associated with a lichen.

The highest values for phosphorus were obtained with samples from

Cape Royds and "Sugarloaf Ridge." The single sample from Kar Plateau contained a re la tiv e ly high quantity of phosphorus (115 ppm). This sample was very moist soil from beneath a moss.

The most interesting data are those on ammonium and phosphorus from the knoll near Quadrat I , on which Prasiola crispa occurred.

Amnonium was extremely abundant in the immediate v ic in ity of the alga, 197

its concentration ranging from 65 ppm under and around the Prasiola to more than 20,475 ppm a short distance away. (It is significant that nitrite was detected at two of the three sites examined on the knoll, being highest where the ammonium was highest—an indication that the ammonium was being very slowly oxidized.) The phorphorus concentration was also very high at all three sites, but the ratio of ammonium nitrogen to phosphorus was much lower under the Prasiola, an indication that the alga was absorbing ammonium fa r more rapidly than phosphorus.

It most cases, data on the total concentration of nitrogen was supported by the data on ammonium, nitrate, and n itrite nitrogen concentrations, usually being greater than the sums of the individual nitrogen compounds.

This probably is due to the different extraction methods employed (the samples received far more drastic treatment in the Kjeldahl analysis than in the mild acid extraction performed fo r the Hellige-Truog analyses) and to the fa ct that nitrogen was present in other forms. The sample collected near Prasiola did not conform to this logically explained pattern, however; the total nitrogen values were five times less than the values for ammonia. This is probably explained by the volatilization of the ammonia during storage and during the drying and s iftin g procedures.

By the same token, the extremely high concentrations of ammonium can probable be attributed to the acidity of the soil: the highly ammonified soil had a pH of 7.48, while the two nearby soils had pH values of only

4.80 to 4.86. The uric acid in skua droppings probably accumulated on the poorly drained knoll (which was used for a perch), lowering the pH.

The lower pH caused ammonia evolved by the hydrolysis of urea to accumu­ la te ; the ammonia in its turn (now ammonium ions) raised the pH as i t accumulated. 198

The other two elements of interest are potassium and magnesium.

The somewhat higher quantities of potassium at Cape Royds may be attributed to weathering of the kenyte rocks, which contain abundant amounts of potassium. Concentrations of potassium in the other regions were generally low, except in the saline study pond near Quadrat IV, which was situated in a very large, amphitheatre-like depression.

There appeared to be a negative correlation between the presence of plants and the existence of magnesium. There were exceptions, however, and the reality of such a relationship cannot be established; it may be only an apparent relationship. Blue-green algae appeared to be more tolerant of magnesium than either mosses or lichens. Further research w ill be necessary to c la rify this point.

Nitrogen.--Tables 14 through 21 summarize the data on the nitrogen contents of plants, soils, and water samples, obtained by microkjeldahl analysis and with the Urograph.

Table 14 presents nitrogen content values for bird droppings, guano, and associated soils. It indicates that skuas and penguins contribute significant quantities of nitrogen to terrestrial ecosystems. Fresh skua droppings contained nearly 25 per cent nitrogen. The data indicate also that the nitrogen is mostly insoluble in water: the solid fraction of skua droppings contained 24.674 per cent nitrogen, while the somewhat diluted liquid fraction of the same sample contained one hundred times less nitrogen. Table 15 indicates that waters usually contained very small (or even indetectable) quantities of nitrogen, a further indica­ tion that much of the nitrogen in terrestrial ecosystems is present in insoluble compounds. The highest values for nitrogen in water samples 199

TABLE 14

NITROGEN CONTENTS OF BIRD DROPPINGS, GUANO, AND ASSOCIATED SOILS'

Determined by microkjeldahl analysis.

Source of Details and Locality Nitrogen Content, Sample per cent Remarks

Williamson Fresh skua 24.674 Solid fraction of Rock Area droppings sample scraped from surface of snow.

Di tto D itto 0.230 Liquid fraction, diluted with melted snow.

II Fresh penguin 0.104 Mean of 3 liquid droppings (0.003, 0.285) fractions; all diluted with melted snow con­ tained in origina sample.

II Abandoned 0.303 Top layer of guano penguin (0.278, 0.338) partly washed colony in away; consider­ West able mineral Rookery s o il. Nf4.

Cape Royds Edge of 11.01 From easternmost Adelie part of rookery. Penguin Part of sample rookery relatively fresh.

Ditto D itto 0.455 200 TABLE 15

NITROGEN CONTENTS OF WATER SAMPLES

Determined by microkjeldahl analysis.

Source of Details and Locality Nitrogen Content, Sample per cent Remarks

Cape Royds Ponds with 0 .000 No macroscopic Area bathing algae. JN=2. skuas

Ditto Di tto 0.007 Much macroscopic blue-green algae. N=2.

II Small saline 0.023 Visible white salt pool near deposit. Backdoor Bay II Seawater from 0.000 Arrival Bay

II Green Lake 0.000 Near green and blue-green algae. II Seepage area. 0.000 Mats of blue-green algae.

II D itto 0.016 Water in small seep­ age ditch filled with a filamentous green alga. II Pony Lake 0.000 II Small ponds 0.002 N=2. near W end of Blue Lake

II Small temporary T ra c e ^ No plants. pool on edge of Quadrat I 201 TABLE 15.--(continued)

Source of Nitrogen Content, Details and Locality Sample per cent Remarks

Cape Royds Royds study 0.000 Contains blue-green Area pond algal mats. Nf2. (continued)

Williamson Stream near 0.003, Run-off from Rock Area Ad£l ie 0.236 "North H ill." Penguin rookery

Di tto Runnoff water 0.016 Abundant Prasiola. from Ad£lie In rookery. Penguin rookery

Ice from side 0.007 From snow and run­ of North o ff. H ill

Snow and ice Traced) Near large colony on N flank of of Caloplaca. "Bryant" ("Pat's Peak")

Kar Plateau Study pond 0.003 Small pond (50 m in diameter) next to Quadrat Illb . Abundant blue- green algae.

Mi ers Val1ey "Mi ers 0.000 Ca. 250 m from region Stream" Miers Glacier. Moss nearby on sand.

Ditto Di tto 0.010 Near Lake Miers.

Lake Miers 0.000 Nf2. One sample from pool of water in ice crack con­ taining blue-green algae.

D itto 0.003 Near outflow of the lake. 202 TABLE 15.—(continued)

Source of Nitrogen Content, Details and Locali ty Sample per cent Remarks

Miers Valley Study pool 0.001 Small (16 m region diameter) pond (continued) filled with blue- green algae. Nf3

Ditto Temporary 0.013 Small pools in the meltwater Nostoc globules. pools near (The alga con­ study pond tained 2.178 Der cent nitrogen).

The Strand Small (3x6 m) 0.007(b) In or near skuary. Moraine pool near Blue-green algae W shore common.

^"Trace" indicates that a small amount of nitrogen may have been present (in both cases, less than 0.003 per cent). ^The nitrogen content of soil from the bottom of the pool was 0.111 per cent. 203 TABLE 16

UREA CONTENTS OF WATER AND SOIL SAMPLES FROM ROSS ISLAND

Source of Sample Urea Content, ppm

Cape Royds

Pony Lake 0

Green Lake 0

Run-off from melting snow 0

Small, temporary meltwater ponds near Blue Lake 0

Temporary meltwater ponds used fo r bathing by skuas 0

Williamson Rock Area

Guano from West Rookery (aqueous extract) 870

P a rtia lly mineralized guano from West Rookery 530 (aqueous extract)

Run-off from West Rookery. Prasiola abundant. 40

Run-off from West Rookery (S side of "North H ill" ) 20

Ice (below previous sample) 0

Skuary soil from Quadrat I I (aqueous extract) 0

Skuary soil from N slope of "Bryant" 0

Snow and ice near large colony of Caloplaca 0 (N slope of "Bryant")

Skuary soil from summit of "Bryant" 0 204 TABLE 17

COMPARISON OF THE NITROGEN CONTENTS OF SOILS ASSOCIATED WITH PLANTS AND OF SOILS NOT ASSOCIATED WITH PLANTS

Determined by microkjeldahl analysis.

. . Nitrogen Content, Category p“r cent

I. Soils not associated with plant growth

A. Guano (penguins and skuas)

Fresh or re la tiv e ly so 13.051 3

Old 0.298 4

Diluted by snow collected 0.104 3 with sample

B. Other soils 0.019 119

Nonskuary areas (excluding penguin rookeries)

The Labyrinth 0.015 11

Near Quadrat I l i a 0.010 4

Near "Miers Stream" 0.007 2

Near Lake Miers 0.005 4

S wall of Miers Valley 0.035 10

"Miers Ridge" (v ic in ity of 0.019 9 Quadrat IV)

Cape Crozier (S of rookeries) ------

Mean of nonskuary areas: 0.019 per cent 205 TABLE 17.--(continued)

Nitrogen Content, Category per cent N

Skuary areas(fl)

Cape Royds region 0.017 48 (including Quadrat I)

Knoll near Quadrat l(b ) 0.252 3

Rocky Point and Horseshoe Bay areas 0.023 3

The Strand Moraine 0.012 2

Dailey Islands 0.008 1

Williamson Rock area . . 0.149 12 (including Quadrat II ) ^ CJ

Southeastern part of Kar Plateau

On sandstone 0.025 10

On dolerite, etc. 0.021 16

Mean of skuary areas: 0.048 per cent

II. Soils associated with plants

Nonskuary areas (excluding penguin rookeries)

The Labyrinth ------—

Near Quadrat Ilia 0.054 5

Near "Miers Stream" 0.010 10

Near Lake Miers 0.044 3

S wall of Miers Valley 0.063 6

"Miers Ridge" (v ic in ity of 0.058 19 Quadrat IV)

Cape Crozier (S of rookeries) 0.026 7

Mean of nonskuary areas: 0.043 per cent 206 TABLE 17. — (continued)

Nitrogen Content, Category per cent N

Skuary areas

Cape Royds region (including 0.039 21 Quadrat I )

Knoll near Quadrat I 0.298 3

Rocky Point and Horseshoe 0.065 6 Bay areas

The Strand Moraine 0.132 6

Dailey Islands ------—

Williamson Rock area . . 0.145 13 (including Quadrat I I ) ( C'

Southeastern part of Kar Plateau

On sandstone 0.049 5

On dolerite, etc. 0.110 9

Mean of skuary areas: 0. 095 per cent

^"Skuary areas" are skuaries themselves or areas otherwise frequented by skuas; on Kar Plateau, the whole southeastern corner is considered a "skuary area" because skuas fly over i t from the nesting area on the shore to the small pond near Quadrat Illb . ^ T h is area is tabulated separately because the values are for shallow, undrained soil on kenyte bedrock; the other areas in the Cape Royds region are somewhat better drained, and organic matter does not accumulate as i t does on the knoll. (c) Because plants (lichens and P_. crispa) are so common in the vicinity of Quadrat II, the distinction between soils closely associ­ ated with plants and soils not closely associated with plants is less meaningful; therefore, the values for the Williamson Rock area are included under both major categories of soils, except fo r one sample. 207

TABLE 18

COMPARISON OF THE NITROGEN CONTENTS OF ALGAE, MOSSES, AND LICHENS AND OF THEIR ASSOCIATED SOILS

Determined by microkjeldahl analysis.

m ±. Nitrogen Content, per cent Type of Plant Associated S'olls

Prasiola crispa 5.495 0.245

Blue-green algae 1.734 0.056

Mosses 0.303 0.064

Lichens 0.540 0.061 208 TABLE 19

TOTAL NITROGEN CONTENTS OF BLUE-GREEN ALGAE FROM ROSS ISLAND, MC MURDO SOUND, AND SOUTHERN VICTORIA LAND AND OF THEIR ASSOCIATED SOILS

Determined by microkjeldahl analysis.

Collection Site Total Nitrogen Content, per cent Alga Soil Underneath Alga

Cape Royds Area

Study Pond 2.861

Blue Lake 2.278

Green Lake 0.429 (N=2)

Coast Lake 3.401

Small, temporary, 1.230 alga-filled meltwater pond (bathing skuas)

Kar Plateau

Study Pond (on ice) 2.255 (N=2)

On fin e sandy soil 1.849 0.071 (N=2) near study pond

Miers Valley Region

Lake Miers 1.990

Near Lake Miers 0.047 (N=3)

S wall of Miers Valley 1.842 0.076 in meltwater drainage channel

"Miers Ridge" (v ic in ity of Quadrat IV)

On sand 1.494 0.161

In meltwater pools 2.533 209 TABLE 19. —(continued)

Collection S ite Total Nitrogen Content, per cent Alga Soil Underneath Alga

Miers Valley Region (continued)

Study pond 0.447 (chipped 0.34-0.36 (Nf2) from ice on 18 XI 68 ) (in and at edge of pond)

0.716 (14 I 68 ) 0.022 (0.4 m from edge of pond)

0.023 (0.014, 0.029) (Nf7) (1 m from edge of pond)

0.007-0.021 (N=2) (3-4 m from edge of pond)

0.003 (water in pond)

The Strand Moraine

Sandy slope 2.097 0.332 (sand sifted from sample)

0.092 (soil under alga) TABLE 20 210

NITROGEN CONTENTS OF MOSSES FROM ROSS ISLAND, MC MURDO SOUND, AND SOUTHERN VICTORIA LAND AND OF THEIR ASSOCIATED SOILS

Determined by microkjeldahl analysis.

Total Nitrogen Content, per cent Locali ty Moss Soil Underneath Moss

Cape Royds Area

Near abandoned 0.271 0.051 rookery

In Quadrat I 0.017 (N=3)

0.028 (N=3)

0.008

0.015

0.007

0.007

Rocky Point

0.103 (N=6 )

0.201 0.111 (N=3)

Cape Crozier

Near c liffs above 0.408 0.014 (N=2) Emperor Penguin (soil under moss) rookery, south of 0.037 (from East Rookery moss clod)

Kar Plateau

Near Site KM 3 in 0.759 0.106(a) Quadrat Ilia 0 .0 3 3 ^ 211 TABLE 20. — (continued)

Locality Total Nitrogen Content, per cent__ J Moss Soil Underneath Moss

Kar Plateau (continued)

Near Quadrat Ilia on 0.628 0.106(a) exfoliating boulder

70 m west of Quadrat 0.1810.071 (Nf2)^c^ Illb

Near small glacier 0.598 - west of Quadrat Illb

On Beacon Sandstone 0.140

0.016 (0.008. 0.023 (N-2)

0.036

On Ferrar Dolerite at ------0.051 Point Retreat

Eastern edge of ------0.212 (_N=2)^a^

PlateaU 0 .5 0 5 ^ 0.120^a *

0.034 (N=2)

Miers Valley Region

Near Miers Glacier 0.126 0.000 (near "Miers Stream")

Near stream flowing ------from Lake Miers 0.000

On south wall of ------0.069 valley

Western part of 0.188 0.041 "Miers Ridge"

Near Quadrat IV 0.035 (N=3)(f ) 0.034 (N=2)(a)

0.027 (N=4)(g) 212 TABLE 20.— (continued)

Locality Total Nitrogen Content, per cent Moss Soil Underneath Moss

The Strand Moraine

West side, in ------0.184 (N=2) skuary 0.216 ------/

(a)sample sifted from moss sample.

^ 4 0 cm from moss growth. (^Nitrogen content of associated blue-green alga: 1.849 per cent. ^Sample associated with a blue-green alga. (e^Mean value for mixtures of various proportions of moss and sand (N=9). ( f ) ~ Including adhering sand. ^ S o il from under the moss. A 2:1 aqueous extract of the soil sample contained no detectable nitrogen. TABLE 21

NITROGEN CONTENTS OF LICHENS AND OF THEIR ASSOCIATED SUBSTRATES

Determined by microkjeldahl analysis.

Nitrogen Content, per cent Species Locality Details and Remarks Lichen Soil Underneath Lichen

Usnea (Neuropogon) All 0.392(a) 0.071 N=13 (lichen), N=5 (s o il). antarctica (0.226-0.587)

0.008 (soil nearby). f[=3.

Ditto Kar Plateau 0.297 0.051 Near sandstone deposit.

Rocky Point 0.392 0.103 Umbilicaria also present.

Igloo Spur 0.024 Usnea abundant in polygon troughs.

Cape Crozier 0.448 From polygon trough. Sample was kept 5 years at ambient temperature.

Umbilicaria spp. Kar Plateau 1.203^) From various substrates near (1.019-1.330) Quadrat Illb (Nf3). (c) Xanthoria sp. "Sugar!oaf 0.016 0.218 The value for soil is the Ridge" (0.036-0.744) mean for 7 samples from the^ W part of the ridge. TABLE 21.— (continued)

Species Locali ty Nitrogen Content, per cent Details and Remarks Lichen Soil Underneath Lichen

Mixture of Xanthoria "Sugarloaf 3.820 0.218^cHhe value for soil is the sp. and Prasiola Ridge" (0.036-0.744) mean for 7 samples from crispa the W part of the ridge.

Caloplaca elegans var. Di tto ------Ditto Ditto pulvinata

Quadrat I , 0.020 N=ll. and v ic in ity

^ S o l berg (1970) obtained values of 0.71 and 0.35 per cent for Usnea dasypoga; the la tte r value was for the central cord of the lichen only. (k^Solberg (1970) obtained a value of 1.99 per cent for Umbilicaria hirsuta. (c) From the general vicinity of the lichens, but not in intimate association with them. 215

were contained in runoff from the large Adelie Penguin rookery near

Quadrat II (0.236 and 0.016 per cent), in association with Nostoe

globules in temporary pools near Quadrat IV, and at Cape Royds.

Table 16 presents data on the urea contents of water and soil

samples from Ross Island. No urea could be detected in samples from

Cape Royds, but large quantities of urea were detected of four samples

collected in or near the Adelie Penguin rookery near Quadrat I I . I t is

inferred that the urea originated from microbial activity on the uric

acid in penguin guano. Uric acid, being nearly water insoluble, would

tend to remain in s itu ; urea, being very water soluble, would tend to

be dispersed by flowing water. The lack of detectable quantities of urea

in the Cape Royds samples is attributable to the small size of the

rookery there, the large distances from the rookery at which most of

the samples were collected, and to the earliness of the season, when

most of the uric acid being excreted by, for example, bathing skuas,

would not have been oxidized.

When the concentrations of nitrogen present in soils associated

with plants are compared with those in soils not associated with plants,

i t is found that there is about twice as much nitrogen in the former

soils (Table 17). This relationship holds for both skuaries and

non-skuary areas. The data suggest that plants tend to accumulate

nitrogen from the environment, in addition to being dependent upon

adequate concentrations of nitrogen.

Prasiola crispa accumulates far more nitrogen than other plants, even more than blue-green algae, many of which fix atmospheric nitrogen (Table 18 ). Mosses accumulated less nitrogen than any of 216 the other plants (although the possible presence of small quantities of sand could be responsible for the somewhat lower concentrations of nitrogen found in mosses). The nitrogen contents of soils associated with blue-green algae, mosses, and lichens were about 0.060 per cent, while soils associated with crispa contained four times as much nitrogen—0.245 per cent. Undoubtedly, P_. crispa requires more nitrogen than the other types of plants; at the same time, however, i t is capable of absorbing high amounts of nitrogen. Letts (1913) found that P_. crispa absorbed large quantities of ammonia from solution.

Table 19 summarizes data on the nitrogen contents of blue-green algae and of their associated soils. The data indicate that blue-green algae may contribute small amounts of nitrogen to the s o il, but the data are more or less inconclusive in this respect. The most convincing evidence for such an effect appears to be that for the small study pond on "Miers Ridge." The closer the association there was between soils and algae there, the higher the concentration of nitrogen. In and at the edge of the alga-filled pond, the nitrogen concentration was about

0.035 per cent, while 3 to 4 m away, where there were no algal mats, the concentration was only 0.007 to 0.021.

The nitrogen contents of mosses and their associated soils are compared in Table 20. The data are inconclusive with respect to the relationship between mosses and soils because there were two samples in which there was no detectable nitrogen. If these two values are ignored, however, i t is clear that mosses accumulate nitrogen many-fold over the soils on which they grow. The only indication that moss growth 217 may be a consequence, not a cause, of elevated nitrogen levels in the soils under them is provided from a soil sample collected in Quadrat

Ilia , about 40 cm from mosses. Its nitrogen concentration of 0.033 per cent is about double that of most soils that are not associated with plants or with b ird life . Since there were macroscopic blue-green algae in the area, the slightly higher nitrogen content may have been due to algal nitrogen fixation in some way.

Most lichens tested contained more nitrogen thah mosses, especially

Umbilicaria spp. (Table 21) There was a clear difference between the nitrogen contents of Usnea antarctica and Umbilicaria sp. Solberg's

(1970) data on species of Usnea and Umbilicaria are very sim ilar. The only sample of a "nitrophilous" lichen, Xanthoria sp. from "Sugarloaf

Ridge," contained very low quantities of nitrogen (0.016 per cent); on the other hand, the soil on which i t occurred contained quite high quantities of nitrogen (0.036 to 0.744 per cent; mean = 0.744). This situation is exactly the converse of that for the other lichens, which contained higher levels of nitrogen that their substrates. It is possible that nitrophilous lichens (£.£., Lecanora tephroeceta Hue and Xanthoria) require not only specific compounds for growth

(uric acid, urea, ammonia), but also must have them in high quantities.

Since the nitrogen on "Sugarloaf Ridge" was probably mostly in the form of insoluble uric acid, the nitrogen may have been unavailable to the lichen until the uric acid was decomposed to urea or ammonia by microorganisms. 218

Chart II is a flow chart of the movement of nitrogen through terrestrial ecosystems. It is based on the data reported herein and on data found in the lite ra tu re .

Salinity.—Soils in the McMurdo Sound area contained varying amounts of salts. Conductance values ranged from as low as 7 ymho to as high as 40,000 ymho (Graph VI ). Plants were confined to soils with values lower than 3,000 ymho. Blue-green algae were the most tolerant of salinity, while Prasiola crispa was nearly as tolerant. Mosses occurred on soils with conductances of up to 450 ymho, while lichens were confined to habitats in which soil-conductance values were less than 250 ymho.

The salinity tolerances of mosses and lichens appeared to differ considerably from area to area. For example, lichens and mosses were restricted to areas where conductance values were less than 60ymho at

Cape Royds, while on Kar Plateau, they were found where s a lin itie s were a few hundred micromhos. On the whole, however, the generalization that lichens were the most sensitive to salinity and that algae were the least sensitive held for all of the areas. Apparently, certain ions were more toxic than others. Since the s a lin ity tolerances of mosses and lichens were least at Cape Royds, it is possible that either sodium or chloride ions were responsible for the observed differences in salt tolerance. 219

Chart II . Provisional flowchart of the movement of nitrogen through Cold Desert ecosystems. The atmosphere, the lithosphere, and marine ecosystems contribute nitrogen to te rre s tria l ecosystems; marine sources probably contribute most and the lithosphere least. Except for lithospheric nitrogen available to extremely slow-growing saxicolous crustose lichens and molecular nitrogen available to nitrogen-fixing species, marine nitrogen probably is the most abundantly available source; of the marine sources, bird excrement is undoubtedly the most significant. Most of the suggested in ter- compartmental transfers are documented in the lite ra tu re . ATMOSPHERE NITROGEN FIXATION MOLECULAR AURORAL NITROGEN FIXATION NITROGEN DISCHARGE 22

NITRATE AMMONIA

23

MAFllNE ECOSYSTEMS TERRESTRIAL ECOSYSTEMS

PLANKTON NITRATE NITRITE fGUANO NITRATE NITRIFICATION SEAV SPRAY, MARIT ME CLOUDS AND FOG, ETC.

KRILL, PENGUINS URIC AND ALLANTOIN UREA AMMONIA ETC. PELAGIC BIRDS ACID 20 | ■ s \ AMMONIA s £ a sp r a y . Ma r it im e clouds a n d fog ETC. 15-18 i f PLANTS

27 28

MOBILIZATION WEATHERING NITRATE AMMONIA 26 29

LITHOSPHERE 221

Results of the Sandstone Study

The results of the sandstone study were inconclusive, partly

because the problem could not be studied exhaustively, but had to be

fitte d into the already established schedule of observations being

followed at Quadrat Illb . To have adequately studied the reasons for

the restrictio n of Usnea to the sandstone area and the immediately

downwind do lerite would have required a fie ld season's work in its e lf.

The results of the soil s a lin ity (electrical conductance) study

are plotted in Graph XIV. The graph clearly shows that the conductance

values of soil, samples collected in the sandstone area its e lf (mean =

321 pmho) were sign ificantly lower (P<0.05) than those collected in the

dolerite areas (mean = 999 pmho). The crosswinds (N-S) dolerite soils

were considerably more saline (mean conductance values of 1079 pmho

and 1362 pmho, respectively) than were the soils collected in the dolerite

areas along the transect parallel to the direction of the strongest

(E-W) winds (763 pmho and 793 pmho, respectively). Mosses also were

encountered, but only in the least saline sites (squared points on the

graph).

Graphs XV and XVI are plots of the rela tive humidity recorded in

the sandstone and downwind dolerite areas over a ll or part of four days

in late January 1969. The humidity values shown in Graph XV were

obtained with forced-air psychrometers, while those in Graph XVI were

obtained with hair hygrographs and a thermohygrograph. The values agree w ell, except that the hygrograph values, being continuous traces,

fluctuate more; the overall characteristics of the curves obtained by

the two methods, agree. Graph XV indicates that on sunny days the 222

Graph XIV. Conductance of 2:1 aqueous extracts of the soil samples collected along the two 280-m-long, mutually perpendicular transects through the center of the sandstone deposit on Kar Plateau. The mean values in each area are also indicated. Usnea ( Neuropogon) ' antarctica and mosses (squares) occurred where the salinity was lowest. DOLERITE’ 999 jimho CONDUCTANCE AT 25C, pmho SANDSTONE‘321 pmho 2000

s MOSS PRESENT • MOSS ABSENT -1500 Houronoaon common

•SANDSTONE' WEST: 7 9 3 umho EAST: 7fi3 umho (UPWIND) (DOWNWIND)

500

DISTANCE PROM CENTER OF SANDSTONE, m 224

Graph XV. Wet- and dry-bulb temperatures in the sandstone deposit on Kar Plateau and in the dolerite area downwind of the sandstone (top) and the relative humidities calculated for the same areas (bottom). Battery-powered forced-air psychrometers were used to determine the temperatures. RELATIVE HUMIDITY, PERCENT 100-r - - 0 5 1200 1200 69 .6 1 8 2 . . oooooooooo 6929 1. 69 6 . I 0 3 9 .6 1 9 2 9 .6 1 8 2 20 0 0 4 2 1200 0 0 4 2 20 20 400 0 24 1200 0 0 4 2 1200 0 0 4 2 © O VERC A ST, SUN ST, A VERC O © O .69 6 I. 9 2 CLOUDY SI THROUGH CLOUDS E L IB IS V Y N N U S ME O DY LCL PAET ME) h ), E IM T APPARENT (LOCAL DAY OF E IM T

-- E N O T S D N A --•-S 69 .6 1 0 3 SNSOEWTBL TMPERATURE TEM -SANDSTONE,WET-BULB - • - —SNSOE R-UB E PERATURE TEM DRY-BULB SANDSTONE, H— D EIEWE-UB TEMPERATURE ET-BULB LERITE,W ■DO OEIE DRY- B TEMPERATURE LB U -B Y R D DOLERITE, DOLERITE 1200 0 0 4 2 1 . 9 6 I. 31 1 69 .6 1 31 1200 1200

C , T 225 226

Graph XVI. Relative humidity about 3 cm above a soil net and a trough in the sandstone deposit (A and B, respectively) and in the dolerite area downwind of the sandstone (C and D, respectively). The temperatures recorded over a polygon trough in the dolerite area are shown at the bottom of the figure. The data were obtained with recording hair hygrographs (A through C) and with a recording hair hygrothermograph (D and temperature). o o RELATIVE H UM I D IT Y , P E R CENT R E P , Y IT D I RELATIVE UM H po

1200 2400 1200 2400 1200 2400 1200 TEMPERATURE,*F LOCAL APPARENT TIME.h dolerite had a higher relative humidity (ten out of ten determinations),

while on cloudy or partly cloudy days, the sandstone area was often more

humid (seven of thirteen determinations). On the other hand, the hair-

hygrograph data indicate that, while the sandstone was s lig h tly more

humid, the differences were not large. The maximum values obtained

over a trough and a soil net in the sandstone were 77 and 81 per cent,

respectively, the minimum values, 20 and 26 per cent, respectively;

fo r the d o le rite, the values were 76 and 78 per cent and 26 and 26 per

cent, respectively. Thus, in this characteristic, the differences

were re la tiv e ly small.

Graph XVII shows the temperatures measured in the sandstone study,

over sandstone and dolerite areas. On sunny days (28 and most of 29

January), a ir over the sandstone was frequently several degrees warmer

than a ir over the d o le rite, but the converse was also true; on overcast

days, the differences in temperature were insignificant.

Grapfi X V III shows that on sunny days the surface temperatures in

Quadrat Illb were usually considerably warmer than corresponding tempera­ tures in the sandstone area itself and on the dolerite downwind of the sandstone. Since orientation of surfaces with respect to the sun's rays is an important factor in determining their temperatures, there are problems in interpreting the data because it was very difficult to find suitable comparably oriented surfaces. On the whole, however, it appears that the dolerite downwind of the sandstone was sign ificantly cooler a t c ritic a l times (midday, for example) than comparable dolerite in Quadrat Il l b , where there was no influence of sandstone. ------SANDSTONE . ------DOLERITE . AIR OVER CENTER OF SOIL NET, +5cm . AIR IN POLYGON ■ TROUGH,+5em ^ \ Hr

— SUNNY-J-OVERCAST -

2 8 1 .6 9 2 9 1 .6 9 • < ■ i • ■ i ■ i * « ■ » ■ r *. * I ' ' l ■ ■ —.—i— ■ 1 ■— ■—• « 1 * ■ 1 « « t » > * 2400 0600 1800 2400 0600 1200 1800 2400 O TIME OF DAY {LOCAL APPARENT TIME), h

5+

OVERCAST+OVERCAST.SUN VISIBLE t ■ THROUGH CLOUOS 301.69 31 1.70 I 0600 1200 1800 2400 06001200 1800 2400 TIME OF DAY (LOCAL APPARENT TIME), h

Graph XVII. Air temperatures at a height of 5 cm over the center of soil nets (circles) and over troughs (squares) in the sandstone area on Kar Plateau (broken lines) and in the dolerite area downwind of the sandstone (solid lines). 230

Graph X V III. Rock, lichen, and soil-surface temperatures in Quadrat Illb (solid symbols), in the sandstone (open symbols connected with broken lin e s ), and in the dolerite area downwind of the sandstone (open symbols connected with solid lines) on 29, 30, and 31 January 1969. DOLERITE -•-S IT E KBTI 1 (SOIL,Ocm) / > / \ \ .— -SITE KBT 10 (SOIL,Ocm) * -— SITE KBT 5 (8UELLIA per \ \ \ \ ON ROCK, Ocm) / — SOIL NET,Ocm — ROCK SURFACE,Ocm / n $ \ SANDSTONE — SOIL NET, Ocm I'jyPJk / \ \ I ijt * /} \ ! -— ROCK SURFACE,Ocm - -Cr - tJ v •

>

• - SUNNY - | - OVERCAST— 28 1.69 291.69 -----> — i— i— 1—i " * 1 > • ...... ■ » ■ 1 ■ ■ ■ ' ...... ■ - \ ■ « 1 ■ « 1 » > ■ 2400 0600 1200 1800 2400 0600 1200 1800 2400 TIME OF DAY (LOCAL APPARENT TIME) h o H

OVERCAST+OVERCAST.SUN VISIBLE 1 THROUGH CLOUDS -ID- 30 1.69 311.69 2 4 0 0 0 6 0 0 1200 1800 2 4 0 0 0____ 6 0 0 1200 1800 2 4 0 0 TIME OF DAY (LOCAL APPARENT TIME), h 232

Table 22 presents albedo values obtained in the sandstone and dolerite areas. I t clearly shows that the albedo of the sandstone was significantly higher than that of the dolerite.

While the data are not sufficient to explain unequivocally the correlation between Usnea and the sandstone deposit, they are su fficien t to indicate that the sandstone's influence is probably due to its greater albedo, which reduces the temperature to which plants are exposed— especially temperatures above 15 C—and probably due to lower s a lin ity , which might be due to greater moisture in the sandstone (the only comparative moisture determinations made indicate that the sandstone is significantly moister than the dolerite) on to characteristics of the sandstone its e lf. 233

TABLE 22

ALBEDOS OF DOLERITE AND SANDSTONE SURFACES ON KAR PLATEAU

Recorded between 1235 and 1310 h on 28 January 1969 with a Georgi-type radiometer held at a height of 1 m.

Type of Surface Albedo, per cent _ Number of Determinations (N)

Pol eri te '

Rock 12

Sandstone

Rock 19 4

Soil 21 3 DISCUSSION

Soi 1 s

McCraw (1960) established taxonomic units on the basis of the morphology of soils, in Taylor Valley, southern Victoria Land (in the

"McMurdo Oasis"), and other places. He reported that desert varnishes, rock weathering, and carbonate accumulations occurred. Later, he set up the three usual categories: zonal, intrazonal, and azonal soils

(McCraw, 1967). The zonal soils (Frigic S oils), which have very weakly developed pro files, may be divided according to the position in them of soluble m aterials, a scheme that reflects the degree of leaching and, in turn, the moisture regime under which the soils developed (ib id . ).

There are two such subdivisions: (1) soils with accumulations of calcium carbonate and gypsum at or near the surface and ( 2) soils with calcium carbonate, gypsum, and soluble salts distributed more or less evenly throughout the s o il, or concentrated at depth.

Intrazonal soils reflect the influence of some dominant local factor. In this category, McCraw placed (1) soils from guano, (2) soils from algae, and (3) soils of solifluction slopes. He described four azonal soils (i_.e.. > soils that have no recognizable zonal character­ is tic s ): 1 ( ) soils of floodplains and stream channels, 2 ( ) soils on dify scree, (3) soils of rock slopes, and (4) soils of felsenmeer.

Tedrow and Ugolini (1966), employing Markov's (1956) termin­ ology, designated the zonal soils of Antarctica "Cold Desert Soils,"

234 235

reserving the term "Polar Desert Soils" for the Northern Hemisphere,

while Campbell and Claridge (1969), like McCraw (1967), applied the

term "Frigic Soils," which they subdivided on the basis of available

moisture into subxerous, xerous, and ultraxerous Frigic Soils. While

the New Zealanders' terminology is probably the better of the two,

Tedrov/'s and Ugolini's w ill be adopted because i t appears to have

accepted American usage.

Cold Desert Soils are, so far as is known, confined to Antarctica,

while Polar Desert Soils are confined to the high Arctic. The soils

of Peary Land, in northern Greenland (83°N), resemble Cold Desert Soils

more closely than any other soils of the Northern Hemisphere (Fristrup,

1952; 1953).

According to Tedrow and Ugolini (1966), there is an extreme break between Southern Hemisphere tundra and the Antarctic mainland

in the pedologic continuum that is postulated to exist along latitu d in al gradients of polar regions (Tedrow, 1968). There is no comparable gap in the Northern Hemisphere because the continuum is truncated

there; the Southern Hemisphere counterpart takes up where the Northern

Hemisphere counterpart ends. The pedologic continua are of different extent in the two polar regions because Antarctica, a large continent completely surrounded by vast expanses of ocean, is much colder than the A rctic, a re la tiv e ly small, ocean nearly surrounded by land.

With increasing la titu d e, the strength of pedogenic processes decreases in polar regions. Poleward, podzolization decreases and ultimately ceases, organic matter v irtu a lly disappears from the s o il, and calcification, alkalization, and salinization increase. These changes are best explained by poleward decreases in temperature, precipitation, and liquid water.

Tedrow (1968) makes the following comparisons of Polar Desert and Cold Desert Soils:

(1) Both show a distinct desert type of soil formation, with a

desert pavement and a crude A-B-C horizon sequence;

(2) Cold Desert Soils form in a more xeric environment and are

more alkaline and more saline than Polar Desert Soils;

(3) Soils of the high Arctic deserts have an effective organic

component, whereas those of the Cold Deserts of Antarctica

are v irtu a lly unmodified by the organic cycle (Claridge,

1965);

(4) Gypsum layers are common in the "B-C" horizons of Antarctic

soils, but rare in high Arctic soils;

(5) Pedogenic carbonates accumulate in the soils of both regions

( 6) The depth of thaw in high Arctic soils is greater than that

in Antarctic soils;

(7) Summer soil temperatures are greater in soils of the high

Arctic than in those of Antarctica;

( 8 ) Surface boulders effloresce more in Antarctica than in the

high A rctic.

Claridge (ibid. ) lists the following additional characteristics of Cold Desert Soils: (1) they contain few animals, except near the coast; (2) they have no A] horizon; (3) their clay fractions are rich in unweathered rock minerals; (4) they undergo almost no leaching 237

because of the arid climate and the presence of permafrost; and (5)

they are mixed by freezing and thawing.

Like McCraw (1967) and Campbell and Claridge (1969), Tedrow and

Ugolini (1966) recognize a number of azonal soils in Antarctica, viz. ,

evaporite soils, protoranker soils, ornithogenic soils, regosols,

and lithosols.

Evaporite soils occur commonly in the ice-free areas in depres- I sions, basins, and low, fla t drainage ways. Their most conspicuous morphologic characteristic is the salts that concentrate on their

surfaces ( ib id . ). Protoranker s o ils , which have thin organic horizons

that are underlain by brown mineral horizons, occur in a few isolated

places, most commonly near meltwater (ib id . ; Janetschek, 1967).

Ornithogenic soils (Syroechkovskii, 1959) occur in penguin rookeries, the only places where organic matter accumulates to any extent in

Continental Antarctica (Tedrow and Ugolini, 1966). This type of accumulation is quite unlike that in most other parts of the world because the organic matter does not originate in situ, or even nearby, but is transported from marine ecosystems. Regosols occur in areas of fluvial, recent glacial, and other deposits. Lithosols are very extensive in the ice-free areas.

Ornithogenic Soils

Enormous quantities of organic nitrogen are injected by marine birds into the te rre s tria l Antarctic environment as discrete points

(I.e ., in rookeries), creating "guanotrophic habitats" (Leentvaar,

1967) that may be conceived of as "sources" with respect to nitrogen, 238

in contradistinction to the mineral soils of the Cold Deserts, which

may be considered "sinks." Ornithogenic soils (i_.e.., guano) may

contain up to ten thousand times more nitrogen than the zonal soils of

Continental Antarctica. Point "sources" of nitrogen in the Ross Sea

area have been enumerated by Harrington (1960) (Adelie Penguin

rookeries) and Spellerberg (1967a, bj (skuaries), and some of them have

been plotted by Janetschek (1967, Figure 2D).

At Cape Crozier on Ross Island, there are some 175,000 pairs of

Adelie Penguins, 150,000 in West Rookery and 25,000 in East Rookery

(Emison, 1968). The two rookeries occupy a total of 2 km^. The

average concentration of penguins in both rookeries is 0.2 p e n g u i n *m-2 -

(1-1* > eac^ penguin has an area of 5 m^). Emison ( ib id .) estimated

that each pair of successful penguins removed between 180,000 and

200.000 euphausids ( k r i ll) from the Ross Sea to feed th e ir young

during the 1965-1966 breeding season, and that i t would require some

5.2 x 10^ euphausids to rear 5000 chicks. I f data were available, i t would be possible to estimate the rate at which nitrogen is introduced

to the land, the amount introduced per unit area, and the rate at which the introduced nitrogen disperses.

It is useful to compare the estimates for Cape Crozier with similar

estimates fo r Haswell Island, which is located on the Queen Mary

Coast near Mirnyy Station. Pryor (1968) estimates that there are

35.000 Adelie Penguins and about 11,000 other birds on the island during the summer. (Syroechkovskii's (1959) estimates appear to be too small by a factor of 0 .5 .) The former birds consume some 20 T 239

of sea organisms per day according to Syroechkovskii ( ib id . ) (allowing

for the fact that Syroechkovskii's estimates are too low), and the

la tte r , 600 kg. During each summer season of no more than 120 days,

a ll the birds on Haswell Island consume at least 1100 T of marine organisms ( ib id . ). A reasonable estimate for the minimum mass of sea organisms consumed at Cape Crozier in one season is , then, about

13,000 T (13 kT). Thus, at least 3.0 kg of organic matter, probably more, were transported by Adelie Penguins from the sea to each square meter of rookery. Not a ll of this was excreted, however; some was utilized by adult birds, and some was utilized by the growing chicks.

No doubt some was also lost between the feeding .sites in the sea and the nesting sites on land. Again, if data were available, it would be possible to estimate the amount of organic nitrogen transported from the sea.

Guano consists primarily of uric acid, 25 per cent of which is nitrogen. The solid fraction of fresh skua droppings collected near

Cape Crozier consisted of 24.6 per cent nitrogen. Ugolini (1964) found

17.3 per cent nitrogen in recent Adelie Penguin droppings from Cape

Royds, and 11.6 per cent in the top 2 cm of the guano layer. The

11 cm of guano underneath the top 2 cm contained 8.5 per cent nitrogen.

Campbell and Claridge (1966) found 14.3 per cent nitrogen in an occupied penguin rookery on Inexpressible Island and 8.3 per cent from a site at which recently abandoned nest sits were clearly distinguishable.

If 15 per cent is taken as the concentration of nitrogen in fresh guano, and 10 per cent as that in the guano layer as a whole, then, assuming the guano to be 12 cm thick (the top 2 cm of relatively fresh 240 containing 15 per cent nitrogen and the underlying 10 cm of older guano containing 10 per cent nitrogen), the two rookeries at Cape Crozier contain on the order of 18 kT of nitrogen (the density of air-dried guano is 0.7 g/cm3).

If a layer of guano 1 cm thick is deposited at Cape Crozier in a single summer season, and i f fresh penguin guano contains 25 per cent nitrogen when i t is excreted, then some 3.5 kT of organic nitrogen are excreted in a single season. On an areal basis, then, roughly 1.75 kg of nitrogen are excreted on each square meter of rookery in one season.

This gives a value of about 1.75 mg/cm3/day. I f these values re fle c t reality at a ll, then something on the order of 7 kg are excreted by penguins on each square meter of rookery during every breeding season.

The larger value of 7 kg does not necessarily refute the upper lim it of 3 kg obtained by combining the data of Syroechkovskii (1959),

Emison (1968), and Pryor (1968). The former value is probably too large and the la tte r too small. Considering a ll of the uncertainties in the calculations, there is close agreement. Both lines of reasoning indicate that something on the order of 1.0 mg of organic nitrogen is introduced to each square centimeter of rookery during the summer. The true value should probably be estimated as lying between 0.1 and 1.0 mg.

The significance of this fact is revealed by data showing that Cold

Desert S oils, such as those that occur in the "oases," often contain as l i t t l e as 20 pg of nitrogen per cubic centimeter, some 10,000 times less than fresh penguin guano. Some of them contain no detectable nitrogen at a ll. 241

Uric Acid.—In some locations, uric acid, which is the principal nitrogenous compound in bird urine (Sturkie, 1964; Bose, 1944; Levine et al_., 1947; Folk, 1969a^, 1969b;, Lonsdale and Sutor, 1971), affects the compositions of soils fo r only re la tiv e ly short periods of time a fter nesting sites are abandoned by birds (Campbell and Claridge, 1966;

Ugolini, 1964). Under some conditions and in certain situations it may persist longer, however (Jones and Walker, 1964), but it is probably unavailable to plants (e..c[., Winsnes, 1969), and is thus ecologically irrelevant.

Under the proper environmental conditions, uric acid w ill be transformed by microbial a c tiv ity into urea, ammonia, and nitrates.

Uric acid itself, which is only slightly soluble in water at neutral and acid pH's, would probably be distributed as particles (cf. also

Folk, 1969<^, 1969b). Thus, i t would not be found at as great distances from the point source as urea, ammonia, or ornithogenic nitrate, all of which are quite soluble in water. Ammonia would tend to be retained by guano, which is usually acid ic, and uric acid would be v irtu a lly insoluble in acidic water (1 part in 14,000). In contrast to guano,

Cold Desert Soils are extremely basic. Thus, they would tend to give up ammonia (or fa il to absorb i t in the f ir s t place), and to be more suitable for the solution of uric acid. However, since they are usually very dry, their more basic pH is irrelevant with respect to the dispersal of uric acid.

Ugolini's (1964) data reveal that nitrogen is slowly lost from guano in penguin rookeries. He reported that fresh droppings contained

17.3 per cent nitrogen, and that the top 2 cm of the guano layer 242 contained 11.6 per cent nitrogen. The lower 11 cm of the guano layer contained 8.5 per cent nitrogen, while the mineral substratum con­ tained only 0.4 per cent nitrogen. A profile in an abandoned rookery

1.5 km to the north of the Cape Royds rookery contained between 0.0 and

0.8 per cent nitrogen in the upper 5 to 8 cm (Ugolini, 1964; Spellerberg,

1970). Lower down in the profile, the guano contained 0.1 to 0.46 per cent nitrogen (U golini, 1964). On the basis of radiocarbon dating,

Spellerberg (1970) estimated that the rookery had been abandoned for some 300 to 400 years, and was occupied for at least 200 years before i t was abandoned. Jensen (1916) reported 0.03 per cent nitrogen in three mineral soils collected about 0.5 km northeast of the Cape Royds rookery, a value identical to that for a sample from Taylor Valley.

At Inexpressible Island, there was 0.01 to 0.02 per cent nitrogen in a soil sample from a s ite that was probably never occupied by penguins, and 0.01 to 0.04 per cent nitrogen in a very old abandoned nesting mound.

Ugolini's (1964) comparison of the two penguin rookeries and

Campbell and C laridge's*(1966) data re fle ct the disappearance of nitrogen from guano with the passage of time. Jensen's (1916) data show, when they are contrasted with those of Ugolini (1964), that there is also a spatial gradient in the nitrogen concentration of soils at Cape Royds.

The change in nitrogen concentration with time is also revealed by the fact that the liquid fraction of fresh skua dropping near Cape Crozier, Ross Island, contained only 0.23 per cent reduced nitrogen, while the solid fraction contained 24.6 per cent. The la tte r value undoubtedly represents uric acid nitrogen because uric acid 243

contains 25.0 per cent nitrogen. Two older penguin guano samples from

the nearby Adelie Penguin rookery contained 0.53 and 0.88 mg of urea

nitrogen per gram, respectively, while two samples of runoff water

from the periphery of the rookery contained 0.20 and 0.40 mg of urea

nitrogen per m illiliter.

Boyd and Boyd (1963) studied soils in the McMurdo Sound region,

including one from the rookery a t Cape Royds and a number of soils

contaminated with organic nitrogen by human a c tiv ity . Ammonia was

detected in all but one of thirteen soils samples—-that from a location

on Cape Royds outside the rookery. Ammonia was abundant in the rookery

soil and in a soil from McMurdo Station that was contaminated by

sewage (6000 and 600 parts per million (ppm), respectively). The

ammonia content of a soil collected in Shack!eton's dump on Cape

Royds, which consisted of rusted cans, bottles, pony manure, and other

debris from the British Antarctic Expedition of 1907, was 100 ppm,

while that of a second contaminated soil from McMurdo Station was

160 ppm. In the remaining nine so ils, the ammonia content ranged

betwen 6 and 60 ppm. No soluble nitrates were detected in any of the

samples. The data of Allen et al_. (1967) show that a similar situation

exists in the Maritime Antarctic with respect to nitrogen.

Staley and Boyd (1963) detected seasonal changes in the con­

centration of ammonia and nitrate of soils from the vicinity of Hallett

Station in northern Victoria Land, where there also is a large Adelie

Penguin rookery. They concluded only that the changes were correlated with "soil fertility and lichen growth." Similarly, Northover and

Allen (1967) found seasonal variations in the content of ammonia in soils from Signy Island, South Orkney Islands (60°43'S; Maritime

A ntarctica), which they related to the breeding cycles of nesting

birds. Rudolph (1966) found that the amount of nitrogen in soils is

related to the presence or absence of vegetation and to the type of

plants present. The lowest value was obtained with a sample of

unvegetated sandy soil (0.07 per cent nitrogen), the next highest with a sample associated with lichens (0.28 per cent), and the highest with a sample collected under mosses (0.46 per cent), all near the

Cape Hallett Adelie Penguin rookery.

The enormous disparity in the amounts of nitrogen contents of

Antarctic soils must have a very significant influence on the distribu­

tion of te rre s tria l plants, very few of which fix atmospheric nitrogen.

Ornithogenic nitrogen appears to be relatively long lived in the soil,

but quite immobile, since its concentration in soil samples collected as close as 0.5 km to the Cape Royds rookery was comparable to that

in soils collected many kilometers from the influence of birdlife.

Other Potential Sources of Nitrogen. —There are at least three additional sources of nitrogen for plants in Continental Antarctica.

In probable order of th eir effectiveness and a v a ila b ility , they are: nitrogen excreted by or otherwise derived from nitrogen-fixing organisms; the atmosphere (in precipitation and from oxidized n itro ­ genous gasses); and mineral substrates.

Excreted Nitrogen.—Holm-Hansen (1963) and Fogg and Stewart (1968) demonstrated that Nostoc commune Vaucher fixes atmospheric nitrogen in situ under field conditions in Antarctica. The latter authors 245

demonstrated that the cyanophycean phycobionts of some lichens in

Maritime Antarctica fix nitrogen also. Since, however, virtually all

species of lichens in Continental Antarctica contain chlorophycean

phycobionts, nitrogen fixation would have to be an indirect, external source of the element for most Antarctic lichens.

There are numerous reports that nitrogen-fixing blue-green algae excrete nitrogenous compounds into the environment (£ .£ ., Fogg, 1952;

Shields, 1957; Shields et al_., 1957; Stewart, 1963; Mayland and McIntosh,

1966; and Stewart, 1967). In some places in Antarctica, nitrogen originating from the a c tiv itie s of heterocystous blue-green algae must, therefore, have a significant influence on patterns of plant distri­ bution. In southern Victoria Land, such an influence appears to be operating in the Lake Penny-Walcott Glacier area, on The Flatiron in

Granite Harbor, and at Marble Point, where more or less lush stands of nitrophilous lichens occur. This is especially probable in the firs t of these areas, where there is no apparent source of organic or reduced nitrogenous compounds other than blue-green algae.

Mosses are sometimes intimately associated with blue-green algae, which adhere tig h tly to their protonemata. The algae (Nostoc spp.) may obtain necessary moisture from this association, the mosses, nitrogen. On the other hand, Horikawa and Ando (1967) and Matsuda

(1968) report that blue-green algae are harmful to Antarctic mosses.

Nitrogen-fixing bacteria may play a role in plant distribution as well. Dodge (1964, 1965), for instance, reports that Azotobacter occurs in the th a lli of some Antarctic lichens, inducing more luxuriant 246

specimens. Boyd and Boyd (1962) detected Azotobacter in soil of the

Windmill Islands o ff the Budd Coast in Wilkes Land.

Precipitation.--Another potential source of nitrogen for Antarctic

plants is precipitation— in this case almost exclusively snow (Wilson,

1959; Wilson and House, 1965; Claridge and Campbell, 1968; Jones and

Faure, 1969; and Lorius et aj_., 1969). This source might be adequate

for lichens, which grow extremely slowly, but i t would probably be fa r

from adequate for mosses and algae, unless they too grew very slowly,

or unless the nitrogen tended to accumulate. Where nitrates accumulate,

conditions are usually dry (Claridge and Campbell, 1968)—so dry, in

fact, that few macroscopic plants, including lichens, can survive.

The Substrate.—The third possible source of nitrogen is the

substrate its e lf, including clays and rocks. Engster and Munoz (1966)

have discussed the former possiblity, and Stevenson (1959) has pointed

out that there is fixed ammonium in rocks. Mueller (1968) has sug­

gested that nitrate deposits in Chile and in Antarctica are due in part

to nitrogenous compounds leached from rocks and subsequently oxidized.

It is significant, therefore, that Ugolini (1970) has reported that

Xanthoria mawsoni and Pol.ycauliona pulvinata (= Caloplaca elegans var.

pulvinata) deplete silica and iron from basaltic and volcanic rocks

(c f. also Silverman and Munoz, 1970; Gunn and Warren, 1962, pp. 52 and

60; and Claridge et al_., 1971), since bound nitrogen compounds probably would be mobilized in the process.

Substrate (i_.e.., soil and guano) nitrogen is undoubtedly the most

important source of nitrogen. The other potential sources of nitrogen may be available in amounts that are su fficient fo r a few species of 247 lichens, but certainly not for most other macroscopic terrestrial plants in Continental Antarctica. The very small quantities of nitrogen in precipitation at the South Pole, for example (5 parts per b illio n ), deposited at the rate of 5 x 10"^ g/cm^/year (Wilson and

House, 1965)—5 x 10" 6 times slower than at Cape Crozier—and the relatively unobtainable nitrogen bound rocks, would sustain only the very slowest growing lichens.

Importance of Nitrogen in the Environment

Where ice, snow, toxic levels of salts, extreme a rid ity , and wind abrasion do not prevent plant growth, lack of a suitable nitrogen source may. There is good observational evidence that nitrogenous compounds of animal origin (penguin guano, for example) support the growth of terrestrial lichens, algae, and mosses, at least in Continental

Antarctica, Filson's (1966) disclaimer notwithstanding (Dodge, 1964,

1965; Follmann, 1965; Greene et al_., 1967, 1970; Lamb, 1948, 1968;

Rudolph, 1963; Siple, 1938; Siple and Lindsey, 1937; Syroechkovskii,

1959; inter a lia ). While none of these authors proved by experiment that nitrogen—and not, for example, phosphorus—v/as responsible for the correlation between b ird life and certain species of plants,

Holdgate et al_. (1967) have shown that nitrogen is the only major nutrient likely to be present in concentrations low enough to lim it plant growth on Signy Island.

Effects of Nitrogenous Compounds on Lichens and Algae

Certain lichens—for example, Xanthoria mawsoni Dodge, Caloplaca elegans var. pulvinata (Dodge and Baker) Murray, and Mastodia tesselata 248

(Hook. f. & Harv.) Hook. f. & Harv. (the lichenized state of Prasiola

crispa) —are well-known nitrophilous species. In West Antarctica,

Buellia latemarginata Darb. (Lamb, 1968) and Lecanora tephroeceta Hue

(Table 1) are others. Follmann (1965) and Redon (1969) have described

ornithocoprophilic lichen associations in West Antarctica. In East

Antarctica, where the fieldwork was carried out, Lecanora lavae Darb.,

J_. griseomarginata Dodge & Baker, Omphalodiscus exsulans (Th. F r.)

Dodge, and Parmelia coreyi Dodge & Baker appear to be more or less

nitrophilous or ornithocoprophilous.

The sheet-like green alga Prasiola crispa (L ig h tf.) Menegh.,

one of the most nitrophilous organisms known, is strongly ornithoco­

prophilic wherever i t is found. In polar regions i t becomes lichenized

where nitrogen levels are low, constituting the phycobiont (j_ .£ ., the

algal symbiont) of the foliose lichen Mastodia tesselata (Lamb, 1948).

The distribution of "Phormidium autumnale"—which is , according to

Drouet (1962), not a true species, but an ecophene of the cosmopolitan

blue-green alga Microcoleus vaginatus (Vaucher) Gomont—is very sim ilar

to that of P. crispa (Table 23). Both species are v irtu a lly confined

to guanotrophic habitats, and should therefore be considered tru ly

ornithocoprophilic species.

The degree of correlation between the occurrence of most of the

lichen species and organic nitrogen deposits (guano) in bird nesting

sites is not so strong as i t is fo r P. crispa and "_P. autumnale," no

doubt because lichens grow fa r more slowly and are capable of absorbing

and retaining nutrients from the atmosphere (cf. Jenkins and Davies,

1966, in ter a lia ); they are thus capable of subsisting on smaller amounts of nitrogen. TABLE 23

OCCURRENCE IN ANTARCTICA OF ‘ Phormidium autumnale1, AN UNSHEATHEREO AQUATIC ECOPHENE OF

Microcoleus vaginatus (Vaucher) Gomont, AS DETERMINED FROM HERBARIUM SPECIMENS

Specimen(s) Location Collector & Expedition Date Associated Species Indications of Nitrogen-Rich Conditions Remarks

SIPLE 332 MELCHIOR P. A. S ip le , U.S. ASE 14 I I I 40 P. Prasiola crispa (Lightf.) Ag.;.Ringed Oet. F. Drouet (7). ARCHIPELAGO: (1939-41) •' Penguins occur on th e 'is la n d l3). ftr.eca Is la n d . {64''20'S. 62' 56‘ W) 6-10 m elevation.

SIPLE 363 MELCHIOR D itto 4 I I I 40 £ . crispa P. crispa (partly lichenized (■Nastodla Det. F. Drouet. ARCHIPELAGO: •sp.J), with same collection number from Anchorage Anchorage Island. Island (67° 36'S, 68'13'W)

BRYANT 99 MARGUERITE H. M. Bryant, U.S. ASE 22 X II 40 Rookery o f 1500 A delie Penguins(b). Det. F. Drouet. BAY: Lago- (1939-41) te lle r ie Island {67° 53'S, 67' 24'H)

NUTT 54 KNOX COAST: E. T. A p fe l, U.S. NAE 14 I 48 Lamorocystis rosea- P. c ris p a . South Polar Skuas(c »d). Oet. F. Drouet, I I I 49. Bunger H ills (1947-49) ( ‘ Operation ersicina (Kutz) Show Petrels, and Wilson Petrelsl®) Area o f ‘ Bunger Oasis' (66'13'S, Windmill *} fchrot. and present in oasis. is 400-450 to 2. 100'45'E) £.• crispa.

NUTT 59, 60, KIIOX COAST: 0. C. N u tt, U.S. NAE 18 I 48 P. crisoa ( a ll) ; P. crispa : penguins present. Pieces Det. F. Drouet, III/IV 64, and Merritt Is­ (1947-49) (‘Operation ‘ Phormidium tenue' of feather with NUTT 59, 66a. NUTT 66a 49. 66a land, Point W in d m ill') Com., predominating found on moist gravel and on penguin AP-11 (66' (NUTT 61) skeletons; intimately associated with 27‘ S, 107' feathers. See Nutt (1948). 101E)

NUTT 68 and BUDD COAST: D itto 19 I 48 P. crispa (NUTT 71), P. crispa present in area (NUTT 69 Oet. F. Drouet, IV 49. 71 Holl Island, ^lectonsma Nosto- Xbird down intermingled), 70 (feathers; Point AP-13 corum* (irm. (b oth), phormidioid growth form), 71, and 72). (66'26‘ S, 110' Nostoc commune (NUTT South Polar Skuas and A delie Penguins 29‘ E) 68). and C aiothrix breeding on the 1slandieJ. pa rie tin a INUTt 68).

NUTT 86 and ROSS ISLAND: D itto 29 I 48 Nostoc commune There is a small Adelie Penguin rookery Ditto. On soil with crust 87 Cape Royds a t Cape Royds o f some 1500 p a irs v f), o f Nostoc. (77'35‘ S, 166' and South Polar Skuas nest in colonies 09*E). Terres­ scattered over the CapeW). t r i a l. ro -P» to TABLE 23.—(continued)

Specimen(s) Location Collector & Expedition Date Associated Species Indications of Nitrogen-Rich Conditions Remarks

LLA1I0 2199A VICTORIA LAND: G. A. Llano, IGY 3 X II 57 Microcoleus oaludosus. Skuas breed on Gneiss P oint. LLANO 2196 Det. F. Drouet, X 60 and McMurdo Sound Schlzothrix rubella (3 X II 57) collecte d 'near skua, perches.1 I I 65. Area, Gneiss Point (77°24'S, t 163»44'E)

LLA110 2205b ROSS ISLAND: D itto 6-8 X II 57 Prasiola sp. (LLANO P. crispa (LLANO 2205 and 2207). South Det. G. A. Llano (LLANO and 2206 Cape Evans 220obi, schlzothrix Polar.Skuas breed at Cape Evans*'). 2205b) and F. Drouet, (77“38'S, calcicola las IX 62 (LUND 2206). 166«24'E) ‘ Phonal d i uni valder- ianucr ecophene) (LLANO 2206).

LLANO 2222 VICTORIA LAND: D itto No date 'Microcoleus None. Taylor V alley opens onto McMurdo Det. F. Drouet. Note th a t Taylor Valley (probably vaoinatus... and Sound at its E end, and receives marine both the ecophene and (approx. 77° 14-18 X II Phormidium Influences'*1). Skuas breed at the E typical M. vaginatus are 3 9 'S, 162° 57) autumnale... end*’ ). present. 521E) FTDrouet XI. 1959.'

LEECH (no SOUTH SHETLAND R. E. Leech 10 I I I 60 There are at least 4.penguin rookeries Det. F. Drouet, X 60: mjirber) ISLANDS: on Deception Island’ 3) and abundant 'Microcoleus vaoinatus Deception Is­ b ird life'*). P. crispa from Cathedral (Vauch.) Gom., phormidioid.' land, Cathedral Crags c o lle c te d 10 I I I 60 (LEECH ( s .n .) ) . Crags (66’ 00‘ S, 60°34'W)

(a) Perkins (1945). Figures 10 and 11. (b) Eklund (1945). (c) McDonald (1948). (d) Shumskiy (1957). (e) Eklur.d (1961), Plate I I I . If) Stonehouse (1965). (g) Young (1963). Figure 1 (h) Jones and Faure (1969), Figure 25. (1) Kohn et a l. (1971j. U) ChartTDTm (U. S. Hydrographic Office). (k) ft. E. Cameron, personal comnunication (25 IV 69). 251

Effects of Nitrogenous Compounds on Mosses

Data on herbarium specimens and in the lite ra tu re suggest that the unusual endemic Antarctic moss Sarconeurum glaciale (C. M ull.)

Card. & Bryhn, primarily a coastal species, may be nitrophilous

(Greene et al_., 1970). The two other principal species of mosses of extreme southern Victoria Land and Ross Island, where most of the fieldwork was done--Bryum argenteum Hedw. and B^. antarcticum Hook. f .

& Mils.—display no consistent preference for habitats rich in organic nitrogen, so fa r as can be determined from herbarium specimens, although

Horikawa and Ando (1967) have characterized IB. argenteum as a weedy, nitrophilous species. The distributions of mosses appear to be influenced by moisture and salinity.

For example, McCraw's (1967) map of soil types in Taylor Valley,

Victoria Land, reveals that mosses (most lik e ly Byrum spp.) are found almost exclusively near the snouts of glaciers, along interm ittent streams, and beside lakes in the coastal two-thirds of the valley, which is affected by maritime conditions more than the western th ird

(Jones and Faure, 1969; Bull, 1966). S im ilarly, Kohn e t al^ (1971) found between 40 and 50 mats of moss along meltwater streams and

"under stones a t altitudes greater than about 270 m," mostly in extremely wet environments in lower (i,.je., coastal) faylor Valley.

They concluded that the distribution of mosses is controlled directly by available water.

They found about ten nesting pairs of South Polar Skuas near the mouth of Taylor Valley, and the remains of penguins farth er inland in a number of ice-free valleys. Others have reported the presence of 252

preserved carcasses of seals in the "McMurdo Oasis." There is ,

therefore, some transport of organic nitrogen by living animals, and

the occurrence of mosses in the eastern part of Taylor Valley may be

partly attributable to the nitrogen animals carry inland. However, the amount of this "diffused" organic nitrogen must be very small, and it must decrease very rapidly with distance from the coast.

Greene (Greene et al_., 1967) has characterized the distribution patterns'of Bryum argenteum and B^. antarcticum as follows: "Bryum argenteum . . . is particularly abundant in southern Victoria Land and

(on) Ross Island (where) it is often abundant in open situations in the wettest areas of drainage channels or seepage slopes, on scree, on morainic detritus, and on sand and gravel of outwash fans ..., while

B>. antarcticum . . . is . . . lo cally abundant in southern Victoria Land and Ross Island, where i t forms a conspicuous and important element in the sparse bryophyte vegetation along the drier sides of drainage channels and in the drier parts of seepage areas on a variety of substrates" (emphasis mine).

Greene's fie ld observations appear to be corroborated by the interesting pattern of salt crusts on herbarium specimens of the two species. Of twenty-one specimens of B_. argenteum examined, only one had an obvious salt crust, while at least six, and possibly nine, of fifteen specimens of B_. antarcticum examined had apparent salt crusts.

The fie ld and herbarium observations, taken together, suggest an inverse relationship between soil moisture content and soil salt concentration, at least in some habitats. The distinctive distributional patterns of these two species of Bryum may be due to soil moisture and 253

salinity relationships. They also imply that non-nitrophilous or

merely facultatively nitrophilous plants are restricted by environ­

mental factors other than organic nitrogen. The studies of Rudolph

(1963, 1967) and of Gimingham and Lewis Smith (1971) are especially

pertinent in this regard.

"Nitrophily"

N itrophily, according to Rasanen (cited by Barkman, 1958), is

actually a matter of "amrnoniophily." That is , ammonia is responsible

for the presence of so-called nitrophilous plants. As Barkman (ibid.)

points out, however, nitrophily is a very complex pheonomenon that is

far from being explained. The only sure way to s e ttle the question is

laboriously to test in pure culture the nitrogen requirements and

preferences of the plant species of interest.

Ornithocoprophily and Guanotrophy. —The terms "ornithocoprophilic"

or "guanotrophic" can be applied not only to species that occur exclu­

sively in areas with thick, obvious coverings of guano ("guanotrophic

habitats" (Leentvaar, 1967)), but to species in skuaries, Snow Petrel

rookeries, rendezvous s ite s , bathing areas, and perches as w e ll, where a small but continual supply of certain organic nitrogenous compounds

is available in amounts su fficien t for slow-growing plants lik e lichens.

Siple and Lindsey (1937) for example, described two small ponds some

50 km from the sea around which bathing skuas had contributed sufficient nitrogen to support a remarkably lush biota. A sim ilar fe rtiliz in g influence exists on Kar Plateau in southern Victoria Land. There, plant growth is much more abundant near a small skua bathing pool than anywhere else on the plateau, yet the only evidence of b ird life , aside 254 from the appearance of the birds themselves a fte r the pond has melted in midsummer, are nitrophilous components of the comparatively rich lichen flora.

Physiological Considerations

In moist localities near the coast, uric acid probably is the most reliable source of nitrogen. At inland, arid sites, ammonium and n itrate could accumulate (c f. Johannesson and Gibson, 1962;

Gibson, 1962; Claridge and Campbell, 1968; Mueller, 1968; inter a lia ) .

Coastal species dependent upon nearly water-insoluble organic com­ pounds could not exist at inland sites. The ultimate case would be species capable of u tiliz in g oxidized (mainly n itra te ) or molecular nitrogen. In these cases, lichens and mosses capable of assimilating nitrates, and nitrogen-fixing blue-green algae would occur.

Since both absorption and assimilation of n itrate nitrogen and reduction of molecular nitrogen require metabolic energy, while absorption and assimilation of ammonium nitrogen may not, because the latter can exist as neutral NH 3 or NH4 OH molecules, depending upon the pH (Jennings, 1963, Chapter 10), and is already in the reduced oxidation state, atmospheric nitrogen and n itrate nitrogen are apparently less suitable for plants of the harsh cold deserts of

Continental Antarctica.

The pattern of nitrogen-source utilization displayed by J.. tephroeceta suggests that nitrophily exists in lichens because the n\ycobiont ( 1 ) u tilize s very few amino acids, ( 2 ) lacks peptidases or, for some other reason, does not utilize protein derivatives, (3) does not utilize nitrates, and (4) utilizes compounds derived from the excrement of uricotelic animals ( i . e . , birds). Nitrophily in lichens

thus may be considered the manifestation of a lim ited capacity to

u tiliz e nitrogenous compounds, which tends to re s tric t such lichens

to specific habitats--in the case of ornithocoprophilic species, to

guanotrophic habitats.

Lecanora tephroeceta's response to nitrogen compounds appears to

substantiate Rasanen's contention (cited by Barkman, 1958) that

nitrophily is actually a question of ammoniophily. Prasiola crispa,

on the other hand, reveals that another type of nitrophily—"uricophily

—exists as well. Indeed, since all organisms require nitrogen, all

organisms must be considered nitrophilous, sensu lato—even nitrogen-

fixing organisms. Thus, i t is probably more meaningful to categorize

organisms on the basis of their nitrogen nutrition, as Robbins (1937)

and others have done for the fungi. According to their schemes, the

fungi were designated as species able to u tiliz e ( 1 ) molecular-,

n itra te -, ammonium-, and organic-nitrogen compounds; ( 2 ) n itra te -,

ammonium-, and organic-nitrogen compounds, but not molecular nitrogen;

(3) ammonium- and organic-nitrogen compounds only; and (4) only organic-nitrogen compounds. JL. tephroeceta apparently belongs in the third category, while both P. crispa and _B. algens appear to belong in the second.

A more realistic system of classification for ecologists could be established on the basis of whether sources of nitrogen are zoogenic phytogenic, or inorganic. For Antarctic terrestrial plants, such a system would be fa r more meaningful. The following scheme is proposed: 256

A. Nitrogen source organic

1. Nitrogen source phytogenic

a. Nitrogen-source proteinaceous or derived from

the hydrolysis of proteins

i . Protei ns

i i . Polypeptides

i i i . Peptides

iv . Amino acids and related amines

2. Nitrogen source zoogenic

a. Animals uricotelic (birds, etc.)

i . Purines

(1) Uric acid

i i . Ureides

(1) Allantoin

(2) Urea

b. Animals ureotelic (mammals, e tc .)

i . Urea

B. Nitrogen source inorganic (biogenic or non-biogenic)

1. Nitrogen source solid, more or less soluble in water

a. Nitrogen source reduced

i . Ammonia and ammonium

b. Nitrogen source oxidized

i. Nitrites

ii Nitrates

2. Nitrogen source gaseous

a. Molecular This scheme, which, like any other, is subject to modification and refinement, is meaningful in an ecological context for Antarctic terrestrial plants. Species are placed in one or more categories that reflect their relationships to and dependence upon plants (primarily nitrogen-fixing blue-green algae, which probably excrete nitrogenous compounds, but also including mosses and non-nitrogen-fixing blue-green algae where they constitute the organic component of soils (Category A. l.) ) o r animals (Category A. 2 .)--o r their independence of other plant and animal l i f e (Category B .).

According to the scheme, L. tephroeceta belongs in Category A ., as do both B^. algens and P. crispa; they also belong in Category B ., since they u tiliz e inorganic-nitrogenous compounds. Sarconeurum glaciale probably f it s in Category A. also. A ll f i t in one or more sub-categories, however, not necessarily in the same ones, and usually in one more strongly than the others. The sub-categories convey a large amount of information about the distribution of the plants assigned to them. Thus, L. tephroeceta fits most strongly in sub­ categories A. 2. and B. 1. a .; B_. algens fits strongly in sub­ category B. 1. a., and somewhat less strongly in sub-categories

B. 1. b. and A. 2. (there is no information on whether B^. algens utilizes amino acids); _P. crispa fits very strongly, and almost exclusively, in sub-category A. 2. a. i. (1); and S. glaciale probably fits strongly in sub-category A. 2. a. Of the four species, F\ crispa and SL glaciale are probably most dependent upon biogenic nitrogen,

tephroeceta is less so, and B.. algens is least so. Nitrogen-fixing blue-green algae, which would f it in the lowest category, sub-category B. 2 ., would, according to the scheme, be most independent of biogenic nitrogen (although they undoubtedly u tiliz e i t when i t is present in certain forms). In general, the lower in the scheme an organism fits , the more dependent it is of biogenic nitrogen and, therefore, the more likely it is to be found at great distances from birdlife. This independence of biogenic nitrogen will lead to characteristic distri­ bution patterns, patterns that w ill contrast sharply with that of

P. crispa, which belongs in one of the higher, less independent categories. Chart II summarizes information on nitrogen flow in the te rre s tria l environment of Antarctica. CONCLUSIONS

The laboratory and fie ld data indicate that nitrogenous compounds very likely play a primary role in determining the distribution patterns of the lichens, mosses, and macroscopic terrestrial algae of cold desert ecosystems in the McMurdo Sound region of East Antarctica.

Nitrogen occurs in very low quantities outside skuaries and penguin rookeries, but in and near bird nesting areas the concentration of nitrogen is relative high.

The experimental laboratory data imply that not only the quantity but also the form of nitrogen influences the distribution of plants.

This inference is based on the fact that the lichen mycobiont Lecanora tephroeceta Hue and the thalloid green alga Prasiola crispa grew better in culture on certain nitrogen compounds than on others. The signifi­ cance of this fact is that the nitrogen compounds that supported the best growth included uric acid, urea, and ammonium, compounds that occur in abundance in rookery areas. The inference is therefore drawn that the observed correlation between certain species of lichens and algae and b ird life is due to the presence in the environment of adequate amounts of specific nitrogenous compounds. The results of the experi­ ments with the moss Bryum algens, on the other hand, indicate that mosses may have less fastidious requirements for nitrogen than some of the lichens and algae. However, the endemic Antarctic moss, Sarconeurum g lac iale , unlike Bryum spp., appears from lite ra tu re and

259 260

herbarium searches to be more fastidious with respect to nitrogen-

source requirements.

Like nitrogen, soil moisture is an important environmental factor.

Plants usually are confined to soils having moisture contents greater than 1 per cent; algae grow in the moistest sites. The promotive influence of moisture was often negated by toxic levels of salts, however; this effect was seen most clearly in Quadrat I , where both moisture and salts accumulated in a depression on the eastern side of the quadrat. Despite the moist habitat, plants were absent.

The "patchy," discrete, or discontinuous distribution of plants appears to be a consequence of lim iting supplies of nitrogen and moisture, and of excess quantities of salts, the salts being less abundant in well-drained locations and adjacent to snowdrifts. Habitats suitable for plant growth appear to be created by the chance coincidence of adequate amounts of appropriate nitrogen compounds, adequate moisture, and low s a lin ity ; the simultaneous occurrence of these three conditions leads to the presence of vegetation, while the absence of any one of the proper conditions prevents plants from growing.

Terrestrial ecosystems in the McMurdo Sound region appear to be largely dependent upon a marine source of nitrogen. The laboratory analyses suggest that birds are the only source of adequate quantities of nitrogen. While nitrogen-fixing blue-green algae undoubtedly introduce nitrogen into terrestrial ecosystems, their influence seems to be restricted to their immediate vicinities. SUMMARY

The crustose lichen mycobiont, Lecanora tephroeceta Hue, grew

best in axenic culture on reduced nitrogen compounds, especially on

neutral compounds. Nitrates and polar compounds were not suitable for

growth of the fungus. Prasiola crispa, a sheet-like green alga, grow

best on uric acid, a compound that occurs in abundance in penguin

guano and skua droppings.

Laboratory analyses of soil, guano, plant and water samples

indicate that nitrogen is present largely in non-water-soluble form,

and that plants tend to accumulate nitrogen from the environment.

Prasiola crispa was associated with moist, nitrogen-rich soils, and

accumulated much more nitrogen than the other types of plants

(blue-green algae, mosses, and lichens).

Plants occurred in the moistest habitats, except where s a lin ity was high. Algae were most tolerant of salinity, and grew in the moistest

sites; blue-green algae were most abundant in depressions where both

salts and moisture accumulated.

261 t

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