CHAPTER 5 �LORA AND VEGETATION OF THE CHUKCHI-IMURUK AREA Charles H. Racine and J. H. Anderson

SUMMARY The proposed Chukchi-Imuruk National Reserve has a rich flora and a diverse vegetation on a variety of sites, reflecting a complex late Quaternary physiographic and biogeographic history. In 1973, 326 vascular species or subspecies and around 100 species of lichens and mosses were collected. Since the spruce woodlands and certain other locations were not collected, the total vascular flora of the area is estimated at 350 species. This, despite a moderately severe maritime-subarctic climate. There are 2 tree, 10 shrub, 25 dwarf shrub, 50 graminoid, 224 forb and 15 cryptogam species in the known vascular flora of the tundra zone. These are tabulated with indications of regional physiographic distribution. Sixty lichens are listed separately. Range knowledge was extended for 32 vascular species in the 1973 collections, including 17 extensions from outside the Seward Peninsula. Among lichens, Anaptyahia bryorum was collected for the first time in Alaska. Eighty-eight of the vascular species fall in one or another of Hulten's seven categories of Beringian radiant plants. None of the known species are endemic in the area, but 11 are limited or nearly limited in North America to the Seward Peninsula. Several locations, like Serpentine Hot Springs and the Lost Jim Lava Flow, are of special floristic interest. Floristic elements (species groups) in the area are coastal, Bendeleben Mountains, limestone domes and boreal. There appears to be a northwestward advance of green alder, balsam poplar, white spruce and certain shrub willows, possibly in response to an ameliorating climate during the past few decades. 1 The vegetation of the Chukchi-Imuruk area is referable to S. B. Young s Zone I shrub tundra. About 50 stands were sampled on most of the major kinds of sites. Ordination of the stand samples together with field observations and species list comparisons led to the establishment of 20 vegetation types, defined by dominant taxa and life forms (e.g. Dryas Dwarf Shrub Tundra) in five physiognomic classes. The latter are Forest and Woodlands, 3 types; Shrub Thickets, 4 types; Tussock-Dwarf Shrub Tundra, 3 types; Dwarf Shrub Tundra, 4 types, and the most diverse floristically; and Meadows (dry, wet and aquatic), 6 types. A sixth physiognomic category, rock deserts, is recognized but not differentiated into types. This classification is roughly parallel with earlier schemes of Hanson and Pegau for other parts of the Seward Peninsula. Vegetation types are described and discussed with reference to positions on environmental gradients, particularly the topographic-moisture gradient, and with reference to certain geomorphic features, like high-centered polygons and beach ridges. Special ordinations of two sets of data illustrate shifting species dominance among stands in the same type. General vegetation-site relationships are apparent, but there is much overlap or intergradation of the floristically and environmentally broadly defined vegetation types. A precise vegetation classification is not yet possible. Nevertheless, the

38 39 present scheme is suitable for regional-scale land-use planning and manage­ ment. It may also serve as a guide in future field work and analysis leading to the establishment of associations per se and the close correlation of these with site factors, as will be needed for local, large-scale planning and management. The 1973 work supports D. M. Hopkins's suspicions that cottongrass tussock­ dwarf shrub tundra (tussock-birch-heath), one of the more widespread vegeta­ tions in the area, is changing toward a kind of upland bog. The underlying process seems to be sphagnum moss invasion of inter-tussock hollows, in a climate that may be warming. Vegetation maps of the Espenberg Peninsula at 1:250,000 and Cape Espenberg at 1:63,360 are presented. These maps were made partly as an experiment in the use of Landsat imagery, but mostly as a comprehensive expression of some of the results of the vegetation study. They present considerably more infor­ mation for their areas than any previous maps. The first map features 14 map unit classes and a number of map units as small as is feasible to draw. Five of the classes are directly comparable to the present vegetation classification for the Chukchi-Imuruk area. Seven, mostly mosaic classes established in response to spatial and spectral resolution limitations of the Landsat image, are readily interpreted in terms of the classification� and two, drained and partially drained thaw lakes and open shallow water, accommodate obvious physiographic features. The Cape Espenberg map, featuring landform-vegetation units, provides a more detailed representation of the landscape. Instead of a typological classi­ fication, units are designated by individual combinations of landform, physiognomic category, and characteristic species. This map was used sep­ arately by the first author in an evaluation of terrain before and after petroleum exploration on the Espenberg Peninsula. GENERAL INTRODUCTION The proposed Chukchi-Imuruk National Reserve, on the Seward Peninsula, Alaska, features various tundra landscapes and, in the southeast, a forest-tundra landscape (Fig. 1). It is at a lower latitude than the northern boreal forest limit that extends eastward across most of Alaska and western Canada, lying mostly within a coastal strip of tundra along the western edge of Alaska. This lower-latitude tundra zone, resembling the true low Arctic, is a function of a North Pacific maritime climate featuring cloudy, cool, wet and windy summers. The flora is moderately rich and the vegetation diverse in the Chukchi-Imuruk area despite the climate. This is a consequence of a wide variety of sites for plant growth along a complex of environmental gradients from the sea coast to inland mountaintops. The major substrates are loess, quartz sand, volcanic ash, lava, limestone and granite. There is considerable variation in relief, drainage and physiographic position. Most of the area is ungla­ ciated, but periglacial processes have contributed to site diverstty. 40 I 167" 165" 16.3" 162" Korzceuc SOl/ • 1'/0 0 • 0 ()evilMt. Lak.s "5 9 Kilt it. fish 268 0. !:!ls. + o, 01�,1-

66"

,>,. :1,��- Amttric /640

Figure 1. The northwest limit of spruce and major paleobotanical locations.

The position of the northwestern Alaska maritime-subarctic treeline appears to have varied through time, roughly northwestward-southeastward, along with other variations in the vegetation of the Chukchi-Imuruk area (Fig. 1; Table 5). These variations are believed due to climatic changes, changes that were partly responsible for sea level fluctuations (by the storage and release of water in continental glacier ice) and concomitant exposures and inundations of the Bering Land Bridge. Plant and animal fossil material is fairly abundant in the Chukchi-Imuruk area and elsewhere on the Seward Peninsula (Fig. 1). It has been found under lava flows, in lake sediments and in cliff and bluff exposures, and it has been dated from the Pliocene to the present. Studies of this material and work in geomorphology, marine sedimentology and archaeology have contributed to a modest knowledge of the natural history of the Bering Land Bridge and its surroundings, a region known as Beringia. As an intermittent intercon­ tinental land mass, Pleistocene Beringia was critical in the biologic evolu­ tion of northeastern Asia and northwestern North America. On the American side, Hulten (1937, 1973), Colinvaux (1964, 1967), Hopkins (1967, 1972) and Matthews (1974) have written most comprehensively about Beringia . 41 In recent times the flora and vegetation of the study area have been affected by reindeer herding, tundra fires, gold mining, and continuing climatic change (Melchior, this volume). Periglacial processes, permafrost phenomena and soil development continue to exert major effects (Hopkins and Sigafoos, 1951; Hopkins, 1963; Holowaychuk and Smeck, this volume). In this paper Part I treats the flora of the Ch�kchi-Imuruk area, and discusses aspects of past and present geography and habitat relationships of species. Considerations of vegetation follow in Part II. Along with a description and classification of the major vegetation types, the more apparent features of their physical environment are examined. In Part III we present the vegeta­ tion and its environment in the form of vegetation maps. Common names of plants are used when these are well established in botanical and lay circles. On first appearance in each part of the paper a common name is followed by its Latin name. Capitalization of certain specific epithets is in the spirit of Bailey (1949). Generic names are not capitalized when used alone as common names, e.g. sphagnum, dryas, elymus. The tenn vegetation is used in the common broad sense as well as more narrowly to designate individual plant assemblages of any sort when more precise terms, e.g. plant community or association, would be inappropriate or of undetermined applicability. This is consistent with the common uses of climate and soil. A climate, a soil and a vegetation may constitute a meaningful geobotanical unit in nature and as an object of study. Henceforth, references to Holowaychuk and Smeck and to soil types pertain to their paper in this volume. Photographs are by the first author except where noted. PART I . FLORA Background Few plant collections were made in the Chukchi-Imuruk area and vicinity prior to 1973. A. E. and M. P. Porsild collected on the Seward Peninsula in 1926 (Porsild, 1939). They visited places along the south coast, going a few miles inland from Nome where 11 •••it was necessary to collect above 1,000 ft in order to find rare and interesting plants that are Asiatic." Porsild wrote that three fourths of the species collected were Western Cordilleran or Bering Sea Endemic floristic elements or were Asiatic species transgressing into western America. Only one fourth were circumpolar or transcontinental North American. The Porsilds continued collecting to the northwest at Port Clarence, thence along the north coast of the Seward Peninsula until they reached Kiwalik and the Buckland River just east of the Chukchi-Imuruk area. Here they collected the semiaquatic plants Cicuta mackenzieana, Drosera rotundifolia and Utriau­ laria intermedia apparently near their range limits. 42 1 During the 1940 s Robert Sigafoos made extensive plant collections around Imuruk and Lava Lakes in the study area (Fig. 1). His collections are unaccessioned in the Smithsonian Institution and have not been published . In 1966 S. B. Young (pers. co111TI.) collected plants on the southern and western portions of Seward Peninsula from Nome to Wales. Elsewhere in Alaskan Beringia the Porsild brothers collected on Little Diomede Island (Porsild, 1938). Johnson et ai. (1966) described the flora and vege­ tation of the Cape Thompson area on the Chukchi Sea north of the present study area. Young (1971) published an intensive study of the St. Lawrence Island flora, presenting along with this a four-part scheme of arctic floristic zona­ tion. Yurtsev (1972) and Hulten (1973) dealt with phytogeographic relation­ ships across Bering Strait. The flora and vegetation of the Noatak and Kobuk River drainages were treated by Young (1974) and Racine (1976) respectively. These two major rivers enter Kotzebue Sound just across from the study area. Methods During the 1973 field season, 580 specimens were collected, including about 100 lichens and mosses from the Lost Jim Lava Flow. Vascular and nonvascular plants were deposited in the University of Alaska Herbarium, and a set of vascular plants was contributed to the Smithsonian Institution Herbarium. Results Three hundred twenty-six species and subspecies of vascular plants and 60 of lichens were identified in the 1973 collections and are listed at the end of this part (Tables 3 and 4). It is likely that additional species could have been found in the forest-tundra, Bendeleben Mountains and limestone domes area where collecting was limited. The vascular flora of the Chukchi-Imuruk area is now estimated at 350 species. The Cape Thompson-Ogotoruk Creek vascular flora to the north contains fewer species, about 300, although in a much smaller area (Johnson et ai., 1966). Of the 326 Chukchi-Imuruk tundra species, 95 occur in both areas. The Chukchi­ Imuruk vascular flora is considerably larger than that of St. Lawrence Island with around 230 species (Young, 1971). It is also larger than the Barrow and Umiat area floras with 104 and 250 species (Britton, 1967) . Range Extensions Using Hulten's (1968) range maps, it was determined that 32 vascular species had not been collected or observed in the Chukchi-Imuruk area prior to the 1973 work (Table 1). Locations for 15 of these were mapped by Hulten in other parts of the Seward Peninsula, and 17 are new records for the Peninsula. Most within-Peninsula extensions of range into the study area are from the south or west. Of those mapped by Hulten, eight were located in the vicinity of Nome, including AspZenium viride, Care:c oanesaens, HeraaZeum Zanatum, Gymno­ oarpiwn dryopteris, and Veratrum aZbum. The closest previously known locations of Gewn gZaaiaZe, PoZygonwn aZaska.nwn and five other species were southwest of the area. 43

TABLE 1. Plants collected in 1973 beyond their previously known ranges as mapped by Hulten (1968), arranged according to the nature of extension of range knowledge.

EASTWARD EXTENSION Draba kamtsahatiaa

NORTHWESTWARD EXTENSIONS Carex ahordorrhiza Eleoaharis aaic:ularis Carex miaroahaeta Triahophorum pwnilum

SOUTHWARD EXTENSIONS Minuartia aratiaa Saxifraga rivularis Seneaio fusaatus

WESTWARD EXTENSIONS Aahillea sibiriaa Botryahium boreale Minuartia striata Agrostis saabra Draba stenopetala Seneaio pauperc:ulus Aratostaphylos Uva-Ursi Melandrium Taylorae Silene repens

EXTENSIONS ON THE SEWARD PENINSULA(* = known from only one other place on the Peninsula) Artemisia glomerata *Eritriahiwn Chamissonis Polygonwn alaskanum *Aspleniwn viride Gewn glaaiale Saxifraga unalas­ ahaensis *Caltha natans *Gyrrmoaarpiwn dryopteris Seneaio aonterminus *Carex aanesaens *Heraalewn lanatwn *Veratrwn album Cassiope tetragona *Platanthera aonval­ lariaefolia Erigeron hyperboreus 44 For the 17 vascular species not previously recorded on the Seward Peninsula there are 13 range extensions from more interior Alaska regions to the east and three extensions from northern Alaska (Table 1). Although Draba kamts­ ahatiaa, the single eastward extension, is known from south-central Alaska, it seems likely that, if its actual range has only recently been extended, this extension was from the much closer easternmost tip of Chukotka (Hulten, 1968). Some, perhaps even all, of the range extensions noted here may be only appar­ ent, for the species involved could well have been overlooked or their loca­ tions not visited by earlier collectors. The skimpy history of botanical exploration in the Chukchi-Imuruk area sketched above is inadequate for de­ termining actual range extensions. Beringian Species The richness of the Chukchi-Imuruk tundra flora is largely a function of the wide diversity of sites along the coast-interior mountains environmental gradient. Also important is the area's history as part of the intermittent Pleistocene land bridge between Asia and North America (Hulten, 1937; Hopkins, 1967). When interglacial meltings resulted in rising sea levels much of the land bridge, consisting in large part of continental shelf, was inundated. The Chukchi-Imuruk area and other parts of the Seward Peninsula remained high and dry, thereby providing a long-term uninterrupted terrestrial setting for plant migration and evolution. During the several periods of land bridge existence, some of considerable duration, the flora of the region, called Beringia, was continuous between the Asian and North American parts. Hulten's comprehensive studies of range maps for the arctic and boreal vascular species led to the conclusion that many species evolved in and spread, or radiated, from Beringia into Asia and North America in interglacial and postglacial times. Several patterns of equiformal progressive range areas were recognized (Hulten, 1937, 1963; Table 2). Species whose provenance is Beringia, particularly the land bridge and vicinity, are called Beringian species. The preceding review indicates why a significant portion, 27 percent, of the Chukchi-lmuruk tundra flora consists of Beringian species (Table 2). Pre­ sumably the other species are of different provenances, e.g. Arctic-Montane sources in Asia and North America and the Continental Western American pro­ venance. Hulten (1973) listed 27 species occurring on the Seward Peninsula but unknown across the Bering Strait in easternmost Chukotka (the Chukotsk Peninsula region). Eleven of these are in the Chukchi-Imuruk flora: Androsaae aham­ aejasme ssp. Andersoni, Boykinia Riahardsonii, Dryas oatopetaia ssp. aiaskana, Hedysarwn aipinum ssp. ameriaanum, Lupinus aratiaus, Mertensia paniaulata, Polygonum aiaskanum, Popuius baisamifera, Potentiiia virguiata, Seneaio aon­ terminu.s ands. iugens. Seven of these are non-Beringian species of Arctic­ Montane or Continental Western American provenances. It may be that their ranges have expanded to the western Seward Peninsula recently, so that there has not been time for their dispersal and establishment across the Strait. Finding Poiygonum aiaskanum and Seneaio aonterminus for the first time in the Chukchi-Imuruk area in 1973 suggests that these species are still in the 45

TABLE 2. Beringian species collected in the Chukchi-Imuruk area in 1973 arranged in Hulten's phytogeographic categories of progressive equiformal radiant species (see Hulten 1937:38-63).

SOUTHERN BERINGIAN (BILATERAL) RADIANTS Angeliaa Zuaida Ca.Pe::: nesophila Pediau"'la.Pis Langsdorfii Atripl,e:r; Gme"'lini ConioseZinum ahinense Rhododendron aamtsahati­ aum Carex Gme Uni EpiZobium sertu.Zatum Saxifraga nudiaauZis Carex Lyngbyaei Lagotis gZauaa TrientaZis europaea

NORTHERN BERINGIAN BILATERAL RADIANTS Artemisia senjavinensis Geum g Zaaiale Primu"'la tsahuktsahorum Cardamine hyperborea LesquereZZa a.Patiaa PyroZa grandifZora Draba stenopetaZa PrimuZa boreaZis

NORTHERN BERINGIAN SIBERIAN RADIANTS Arniaa frigida C"'laytonia aautifoZia PoZemonium aautiflorum AstragaZus umbel,7,atus Oxytropis Mertensiana Rumex graminifoZius Card.amine miarophyZZa Oxytropis nigresaens Salix Chamissonis Chrysanthemum bipinnatum

NORTHERN BERINGIAN RIGID AMERICAN RADIANTS Arabis a.Peniaola Lupinus aratiaus Saxifraga exil,is Chrysanthemum integrifo"'lium 0:cytropis MaydeZZiana Taraxaawn a las kanum Dodeaatheon frigidum PotentiZZa VahZiana Taraxaaum phymatoaarpum Dryas integrifoZia 46 TABLE 2. Continued

NORTHERN BERINGIAN PLASTIC NORTH AMERICAN RADIANTS Boykinia Riaha.rdsonii Mertensia paniaulata Primula egalikensis Card.canine pu.rpu.rea Oxytropis aampestris Solid.ago multiradiata Erigeron hyperboreus Parrzassia Kotzebuei

NORTHERN BERINGIAN PLASTIC NORTH AMERICAN AND RIGID ASIAN RADIANTS Aahillea sibiriaa Salix alaxensis

ARCTIC-PACIFIC PLANTS Aaonitwn delphinifolium Descu.rainia sophioides Pinguiaula villosa Anemone Riaha.rdsonii Draba ainerea Puccinellia phryganodes Antennaria Friesiana Draba laatea Ranunaulus nivalis ssp. Friesiana Dryopteris fragrans Ranunaulus Pallasii Antennaria monoaep11ala Dupontia Fisaheri Rumex aratiaus Aratostaphylos alpina Eriophorum russeolum Salix arctiaa

Arniaa Lessingii Hierochloe paucifl,ora Salix ovalifolia Botryahium boreale Hippu.rus tetraphylla Salix phlebophylla Carex rariflora Junaus castaneus Saxifraga bronhcialis Carex subspat11aaea Ledwn palustre Saxifraga unalaschcensis Cassiope tetragona Luzula Wahlenbergii Taraxacum kamtsc11aticum Chrysanthemum aratiaum Melandrium affine Tofieldia coccinea Claytonia sarmentosa Minuartia stricta Woodsia glabella 47 process of moving into available habitats in western Alaska. Boykinia Rich­ a:radsonii and Mertensia panicuZata are Beringian species, but radiants from the Yukon Valley, which may be interpreted in Hulten (1937: Plate 12) as located in eastern Beringia. Thus, their establishment as far west as the Bering Strait region may also be a recent event. Androsace chamaejasme ssp. Andersoni is limited to northwestern Alaska and Hulten (1968) regarded it as a local race. Lupin.us arcticus is a bona fide Beringian species; its absence from Chukotka is not understood by the present writers, although we note that it is in a group of species that radiated mostly eastward, and failed to extend their ranges further after the disappearance of Wisconsinan ice in North America (Hulten, 1937). Young (1974) called attention to a situation which may also have contributed to the richness of the Beringian flora. He noted that Beringia is located in a �ind of junction between the great northeastern Asian and northwestern North American mountain systems. The higher parts of the mountains are gen­ erally believed to have been above the surface of the continental ice sheets, which otherwise isolated Beringia from most of North America and restricted North American connections with Asia for extended periods of glacial time (Miller, 1964; Hopkins, 1967). Thus, there were long avenues of more or less interconnected pieces of mountain terrain potentially available for species migration and genetic exchange between Beringia and lower latitude alpine sources. This idea is somewhat at odds with Hulten's (1937) earlier dis­ cussion. Endemism No plants are endemic in the Chukchi-Imuruk area, but several species are known in North America only on the Seward Peninsula. Some of these may have reached the Peninsula by recent dispersal across Bering Strait from Asia. A few additional species are now distributed a little more widely along the northwestern North American coast. With the Seward Peninsula as their likely port of entry and/or Pleistocene range, all these species are designated Seward Endemics, whether or not they are Beringian species as defined by Hulten (1937). Among the Seward Endemics Artemisia senjavinensis, Papaver WaZpotei and Veratrwn atbum were thought to be restricted to the Peninsula (Hulten, 1968), but recently P. WaZpotei and v. aZbum were found in other areas (Hulten, 1973), for example in the Noatak River Valley north of the Seward Peninsula (Young, 1974). Rhododendron aamtscha.ticum ssp. gtandutoswn and Sa:cifraga nudicauZis have been reported from only one other area in North America out­ side the Seward Peninsula. The alpine species (Bendeleben Mountains) Car­ damine miarophyZZa, Gewn gZaciaZe and Oxytropis Mertensiana occur elsewhere only in the Brooks Range. Three additional Seward Endemics, Androsaae aham­ aejasme ssp. Andersoni, PotentiZZa eZegans, and Primuta tsah.uktschorwn, have restricted or disjunct ranges in Alaska with their populations seemingly centered on the Seward Peninsula. 48 Significant Locations Several locations are of special interest for their rare or unusual plants or range extensions. One of these is Serpentine Hot Springs (Figs.° l; 10). Here the warm soils near the springs had temperatures of 15 to 30 C at 10 cm depth. By way of comparison, nearby tussock tundra soils were 4 to 6° C at 10 cm. On the hot springs soils the interior Alaska species Agrostis saabra, AahiZZea sibiriaa and Botryahium boreaZe, among others, are common. Balsam poplars (PopuZus baZsamifera) occur in the vicinity of the hot springs, and around the granite tors the ferns Cystopteris fragiZis, Gymnoaarpium dryop­ teris and Woodsia gZabeZZa were found. A snow patch area at 600 m on Mt. Boyan in the Bendeleben Mountains contains a large and diverse assemblage of plants, including some Beringian endemics. Conspicuous species included Boykinia Riahardsonii, Cardcunine miarophyZZa, Eritriahium Chamissonis, Geum gZaaiaZe, G. Rossii, Oxytropis Mertensiana and Saxi;raga serpyZZifoZia. This area appears to contain many species character­ istic of the Alaska Range and Brooks Range alpine floras. The limestone domes area, particularly Harris Dome, appears to be an impor­ tant location for Seward Endemics (Fig. 16) such as Artemisia senjavinensis and Papaver WaZpoZei. Volcanic ash beach ridges around the Espenberg maar lakes, particularly North Killeak and Devil Mountain Lake (Fig. 14), also bear a colorful and rich flora. Although the Lost Jim Lava Flow did not contain a rich or unusual vascular flora, and lacked evidence of endemism, the lichen flora was outstanding (Table 4). Anaptyahia bryorum was collected there for the first time in Alaska. Floristic Elements At least four floristic elements can be recognized in the Chukchi-Imuruk area. Three of these can be related to different positions on the coast-interior mountains environmental gradient. Characteristic of the coastal element are Chrysantherrrum bipinnatum, Honckenya pepZoides, Lathyrus maritimus, PotentiZZa Egedii, PI'imu.Za boreaZis and Seneaio Pseudo-Arniaa. In the Bendel eben Moun­ tains, a distinct alpine flora includes Boykinia Riahardsonii, Card.amine miarophyZZa, C. purpurea, Carex rariflora, CZaytonia aautifoZia ssp. gramini­ folia, Eritriahium Chamissonis, Geum gZaaiaZe, G. Rossii, Oxytropis Merten­ siana, Potentilla elegans, Primula striata, Saxifraga oppositifolia and s. serpyZlifoZia. A third floristic element is associated with the limestone domes and includes Artemisia senjavinensis, AstragaZus aboriginum, A. umbel­ Zatus, Draba stenopetaZa, Hedysarum hedysaroides, LesquereZZa aratiaa, Papaver WaZpoZei, Parrya nudiaaulis, Phlox sibiriaa, PotentiZZa Vahliana, Salix rotundifolia ssp. Dodgeana and Saxifraga oppositifoZia ssp. SmaUiana. A fourth floristic element comprises boreal species in the forest-tundra in the southeastern part of the area. 49 Additional Phytogeographic Considerations Of particular interest is the distribution of woody species in the study area. Colinvaux (1964, 1967) thought species such as green alder (AZnus al"ispa), balsam poplar and white spruce (Piaea gZauaa) reached their distribution limits in the southern part of the Chukchi-Imuruk area. Both Colinvaux and Hopkins (pers. comm.) felt that the oceanic climatic influence restricted woody plant distribution northward and westward across the Seward Peninsula. It appears now, however, that some woody species are represented farther north than previously realized, particularly in the volcanic ash region of the Espenberg Peninsula. It is not clear whether these are true recent range extensions concomitant with climatic change as Hopkins (1972) has suggested, or apparent extensions due to inadequate observation and collection in the past. Green alder, for example, was found distributed almost throughout the study area, reaching to within about 10 km of the coast in the Espenberg volcanic ash zone (Fig. 2}. The presence of alder there may be a long-standing one, a function of the well drained ash substrate, rather than a consequence of a recently more favorable climate. Balsam poplar, in contrast with alder, does not reach the Espenberg Peninsula, but it does occur north almost to Kotzebue Sound along the Inmachuk River and at Serpentine Hot Springs (Fig. 2).

167" 165· 163" Korzeeve sov.,y0

0 • 9 Otlvll Ml. Lat.11 O � Kil� 0 10 20 30 40 k m �8 I I I l==I Shi!lhmar,/ + ' 0. ,,,..

4/4>.,.

66" . , � ,q

BEN 9£Nofl..E 1. -:I :D McCarthy Mor11h

Figure 2. Locations where green alder (diagonal lines) and balsam poplar {Pb symbol) were observed. 50 TABLE 3. Vascular plants collected in the Chukchi-Imuruk area in 1973. Nomenclature follows Argus (1973) for willows and Hulten (1968) for all other taxa.

HABITAT OR LOCATION CODES AQ = aquatic sites LO= limestone domes BM= Bendeleben Mountains LF= lava flows = OM= dune and marsh sites of MT mesic tundra the coastal zone = ST shrub thicket OT= dry tundra VA= volcanic ash of the Espenberg HS= hot springs Peninsula = IU= interior uplands WT wet tundra (ekr) = extension of known range

LYCOPODIACEAE POLYPODIACEAE Lycopodium aZpinwn IU, OT J Asplenium viride VA, LF, OT (ekr) Lycopodium annotinwn ssp. pungens Cystopteris fragiZis HS, DT VA, HS, OT Dryopteris fragrans LF, OT Lycopodiwn aZavatum ssp. monostaahyon J Gymnocarpiwn dryopteris HS, OT IU, MT (ekr) Lycopodiwn seZago ssp. appressu� Woodsia gZabeZZa HS, OT VA, HS, OT Lyaopodiwn seZago ssp. seZago SPARGANIACEAE HS, LF, OT _./Sparganium hyperboreum AQ SELAGINELLACEAE GRAMINEAE SeZagineZZa sibirica LF, OT J Agrostis scabra HS, OT (ekr) EQUISETACEAE AratophiZa fuZva OM, VA, HS, IU, WT Equisetum arvense DM, VA, HS, IU, WT CaZamagrostis canadensis OM, VA, Equisetum sairpoides VA, OT HS, IU, OT Desahampsia caespitosa OM, VA, OPHIOGLOSSACEAE HS, IU, LO, LF, BM, OT J /Dupontia Fischeri DM, WT Botryahiwn boreaZe HS, ST (ekr) EZyrrrus arenarius DM, VA, HS, OT Botryahiwn Zunaria VA, HS, OT / Festuca al.taiaa 51 TABLE 3. Continued.

Festuaa braahyphyZZa OM, VA, HS, IU, JUNCACEAE LO, LF, OT Festuaa rubra OM, VA, HS, IU, LO, LF, Junous arcticus OM, OT BM, OT Junous oastaneus VA, IU, WT, OT ,• Festuaa vivipara LO, OT Luzula confusa OM, HS, BM, OT HieroahZoe aZpina. OM, VA, HS, IU, LO, Luzula multiflora OM, IU, WT LF, BM, OT LuzuZa parvifZora VA, ST Hieroahloe pauaifZora OM, VA, WT Luzula tundricoZa BM, OT Poa alpina. VA, OT (ekr) Luzula Wahlenbergii IU, WT .r Poa eminens OM PuaaineUia phryganodes OM, WT LILIACEAE Trisetum spiaatwn OM, VA, HS, IU, MT Allium schoenopraswn IU CYPERACEAE Tofieldia cocoinea OM, VA, HS, IU, LO, LF, BM, OT Carex aquatilis OM, VA, HS, IU, LO, LF, Veratrum album HS, IU, OT (ekr) BM, WT Zygadenus eZegans IU, LO, DT Carex Bigelowii OM, VA, HS, IU, LO, LF, BM, MT, OT IRIDACEAE Carex canescens VA, WT {ekr) Carex capitata VA, OT Iris setosa VA, ST Carex ahordorrhiza DM ( ekr) Carex gZaaiaZis LF, OT ORCHIOACEAE Carex glareosa OM, WT Carex Gmelini OM, MT Platanthera aonvallariaefoZia Carex Lyngbaei OM, WT HS, ST (ekr) Carex Mackenziei OM, WT Platanthera obtusata OM, OT Carex maritima DM, WT Carex membrana.oea OM, VA, HS, IU, WT SALICACEAE Carex miorooha.eta BM, DT (ekr) Carex nesophiZa HS, MT Populus baZsamifera VA, HS Carex podocarpa HS, IU, BM, MT Salix alaxensis var. aZaxensis Carex Ramenskii OM, WT BM, ST Carex rarifZora BM, MT Salix aZaxensis var. longistylis Carex sairpoidea IU, WT VA, IU, LF, ST Carex subspatha.aea OM, WT SaZix arotioa OM, VA, IU, BM, OT EZeooharis aaiouZaris IU, WT (ekr) Salix braohyoarpa ssp. niphoolada Eriopho1"Ulrl angustifoliwn OM, VA, HS, IU, IU, LO, LF, OT BM, WT Salix Chamissonis HS, IU, WT Eriophorum russeolwn OM, VA, WT Salix fuscesoens OM, WT, ST Eriophorum Saheuohzeri IU, WT Salix gZauoa var. aoutifoZia OM, Eriophorum vagina.tum OM, VA, HS, IU, LO, VA, HS , IU , LO, ST LF, BM, WT, MT Salix hastata Trichophorum caespitosum OM, WT Salix Zana.ta ssp. Riohardsonii Trichophorum pumilwn IU, WT ( ekr) VA, HS, IU, LO, BM, ST Salix ovaZifoZia OM, WT Salix phlebophylZa OM, VA, HS, IU, LO, LF, OT Salix planifoZia ssp. puZohra OM, VA, HS, IU, LO, LF, BM, ST 52 TABLE 3. Continued.

Sa iix polaris VA, HS, IU, MT Minuartia rubella VA, HS, IU, OT Salix reticulata OM, VA, HS, IU, LO, LF, Minuartia stricta VA, OT (e�r) BM, OT Moeh:t>ingia laterifZora HS, MT Salix roturzdifolia ssp. Dodgeana. IU, OT Silene aaaulis VA, HS, IU, LO, LF, BM, OT BETULACEAE SiZene repens VA, OT (ekr) Stellaria arassifolia IU, WT Alnus crispa VA, IU, LF, ST Stellaria hwnifusa OM, VA, IU, Betula na.na. OM, VA, HS, IU, LO, LF, BM, WT MT, OT Stellaria mona.ntha OM, VA, OT Betula papyrifera ssp. humilis HS, LF WilheZmsia physodes VA, HS, IU, Betula papyrifera X na.na. HS, LF (ekr) OT POLYGONACEAE RANUNCULACEAE Koenigia islarzdica VA, BM Aconitwn delphinifoZiwn ssp. Oxyria digyna HS, BM, OT delphinifolium VA, HS, IU, Polygonwn alaskanum VA, HS, OT (ekr) LO, BM, MT Polygonwn bistorta OM, VA, HS, IU, LO, Aconitwn deZphinifoZium ssp. L F, BM , MT, OT paradoxum BM, MT Polygonwn viviparwn OM, VA, HS, IU, LO, Anemone Drummorzdii VA, HS, IU, LF, BM LO, OT Rwnex arctiaus OM, VA, HS, IU, LO, LF, Anemone narcissiflora ssp. BM, ��T sibirica IU, BM Rwnex graminifolius Anemone pawifZora HS, IU, LO, BM, WT CHENOPOOIACEAE Anemone Richardsonii VA, HS, IU, LO, ST Atriplex Gmelini OM CaZtha natans IU, AQ (ekr) Chenopodiwn glaucrum ssp. salinum HS (ekr) CaZtha paZustris OM, VA, HS, IU, LO, AQ PORTULACACEAE Ranunculus confervoides OM Ranunculus Gmelini ssp. Gmelini CZaytonia aautifolia ssp. graminifol,ia IU, WT, AQ BM, WT Ranunculus lapponicus VA, HS, IU, Claytonia sa.rmentosa IU, ST ST Ranunculus nivalis OM, AQ CARYOPHYLLACEAE RanuncuZus PaUasii OM, VA, HS RanuncuZus pedatifidus OM, WT Cerastiwn Beeringianum OM, VA, HS, IU, Ranunculus pygmaeus IU, WT OT Ranunculus suZphureus BM, MT Cerastiwn Fisaherianum X Beeringianum ThaZictrum alpinwn LO Cerastiwn jenisejense IU, WT Honckenya peploides OM, OT PAPAVERACEAE MeZandriwn affine IU, OT Melandriwn apetalwn OM, WT Papaver Zapponicum OM, VA, OT Melarzdriwn macrosperrrrum OM, OT Papaver Macounii VA, HS, IU, LD, Melandriwn TayZorae VA, OT (ekr) LF, BM, OT Minuartia aratiaa VA, IU, BM, OT (ekr) Papaver WaZpoZei LO, OT Minuartia Rossii VA, HS, IU, BM, OT 53 TABLE 3. Continued.

FUMARIACEAE Saxifraga exilis OM, WT Saxifraga flagellaris VA, OT Corydalis pauciflora VA, HS, IU, ST Saxifraga foliolosa BM, WT Saxifraga hieraaifolia OM, VA, CRUCIFERAE HS, IU, LO, LF, BM, MT, OT Saxifraga hirculus OM, VA, HS, Arabis arenicola HS, OT IU, LO, LF, BM, WT Arabis lyrata VA, OT Saxifraga nudiaaulis BM, WT Barbarea orthoaeras VA, IU, i�T Saxifraga oppositifolia ssp. Card.amine bellidifolia LF, OT oppositifolia BM Cardamine hyperborea VA, HS, IU, LO, Saxifraga oppositifolia ssp. BM, ST Smalliana LO Cardamine miarophylla BM, MT Saxifraga punctata VA, HS, IU, Cardamine pratensis VA, HS, IU, LO, LO, LF, BM, OT, ST BM, WT Saxifraga rivularis IU, WT (ekr) Card.amine purpurea BM Saxifraga serpyllifolia BM Cochlearia officinalis OM, VA, HS, IU, Saxifraga unalaschcensis BM (ekr) OT Desaurainia sophioides OM, VA, OT ROSACEAE Draba ainerea OM, OT (ekr) Draba g labe lla OM, VA Dryas integrifolia VA, HS, OT Draba kamtschatica OM, OT (ekr) Dryas oatopetala ssp. oatopetala Draba lactea IU, OT Dryas oatopetala ssp. ala3kensis Draba Palanderiana BM (ekr) BM ( Draba pilo sa BM , MT (ekr) Gewn glaciale ekr) Draba stenopetala LO, OT Gewn Rossii BM Erysimwn cheiranthoides HS Potentilla biflora IU, LO, OT Erysimwn Pallasii VA, LF Potentilla Egedii ssp. Egedii Lesquerella aratiaa LD var. groenlandiaa OM, WT Parrya nudicaulis ssp. nudiaaulis VA, BM Potentilla elegans HS, BM, OT Parrya nudicaulis ssp. septentrionalis Potentilla fruticosa VA, HS, LO IU, LO, LF, BM, OT Potentilla Hookeriana VA CRASSULACEAE Potentilla hyparatica Potentilla palustris OM, VA, HS, Sedum rosea OM, VA, HS, IU, LO, LF, IU, LO, LF, BM, WT BM, DT Potentilla Vahliana LO Potentilla villosa VA SAXIFRAGACEAE Potentilla virgulata OM Ru.bus araticus V.d., HS, IU, LO, Boykinia Riahardsonii BM BM, ST Ru.bus ahamaemorus Chrysospleniwn tetrandrwn DM, VA, HS, OM, MTVA, HS, IU, LO, LF, BM, WT IU, LD, LF, BM, WT, Parnassia Kotzebuei OM, VA, HS, IU, LO, Spiraea Beauverdiana VA, HS, IU, LD, LF, OT, ST LF, BM, DT IU, Parnassia palustris OM, VA, HS, IU, LO, Sanguisorba officinalis ST LF, BM, WT Saxifraga bronahialis HS, LF, OT LEGUMINOSAE Saxifraga aaespitosa VA Saxifraga aernua IU, WT Astragalus aboriginwn LO, OT 54

TABLE 3. Continued .

Astragalus alpinus OM, VA, HS, IU, LO, CORNACEAE LF, BM, MT, ST Astragalus umbellatus LO, OT Cornus suecica HS, MT, ST Hedysarum alpinum HS, IU, BM, OT Hedysarum hedysaroides LO, OT PYROLACEAE Lathyrus maritimus OM Lupinus arcticus VA Pyrola asarifolia OM, VA, HS, Oxytropis campestris OM, LO, OT IU, ST Oxytropis Maydelliana IU, OT Pyrola grandifZora VA, MT Oxytropis Mertensiana BM, OT Pyrola secunda VA, OT IU, Oxytropis nigrescens OM, VA, HS, LO, LF, OT EMPETRACEAE Oxytropis viscida IU, OT (ekr) Empetrwn nigrum OM, VA, HS, IU, CALLITRICHACEAE LO, LF, BM, WT, MT, OT Callitriche hermaph:r>oditica OM ERICACEAE VIOLACEAE Andromeda poZifoZia VA, HS, IU, BM, MT Viola bifZora BM, OT ArctostaphyZos alpina OM, VA, Viola epipsila VA, ST HS, IU, LO, LF, BM, MT, OT ArctostaphyZos Vva-Ursi IU (ekr) ONAGRACEAE Cassiope tetragona OM, VA, HS, IU, LO, LF, BM, WT, OT EpiZobium angustifoliwn OM, VA, HS, IU, Ledum paZustre OM, VA, HS, IU, LO, LF, BM, OT LO, LF, BM, WT, MT Epilobium davuricum IU, WT LoiseZeuria proaumbens OM, VA, Epilobium Hornemanii HS, ST HS, IU, LO, LF, BM, OT Epilobium latifolium OM, VA, HS, IU, Oxycoccus microcarpus VA, HS, LO, LF, BM, MT IU, WT Epilobium palustre VA, WT Rhododendron camtschatiaum HS, EpiZobium sertuZatum HS, ST BM Rhododendron Zapponicum VA, IU, HALORAGACEAE LO, OT Vacciniwn uZiginoswn OM, VA, HS, Hippuris tetraphyZZa OM, AQ IU, LO, LF, BM, MT, OT Hippurus vuZgaris OM, VA, HS, IU, Vacainium Vitis-Idaea OM, VA, LO, LF, BM, AQ HS, IU, LO, LF, BM, MT, OT MyriophyZZum spicatum IU, AQ OIAPENSIACEAE UMBELLIFERAE Diapensia Zapponiaa OM, VA, HS, Angelica Zuaida HS, ST IU, LO, LF, BM, OT BupZeurum triradiatum OM, VA, HS, IU, LO, LF, BM, OT PRIMULACEAE Cnidium cnidiifoZium OM, MT ConiosiZinum chinense OM, OT Androsace ahamaejasme ssp. Ander­ Heracleum Zanatum HS, ST (ekr} soni OM, OT Ligusticwn scoticum OM 55 TABLE 3. Continued.

Androsace chamaejasme ssp. Lerunan­ PedicuZ.aris parvifZ.ora OM, VA, niana OM, OT HS, IU, WT Androsace septentrionaZ.is VA, OT PedicuZ.aris sudetica OM Dodecatheon frigidwn VA, HS, IU, LO, PedicuZ.aris verticiZ.Z.ata VA, HS, BM, ST IU, LO PrimuZ.a boreaZ.is OM, OT IU, PrimuZa egaiikensis OM, WT LENTIBULARIACEAE Prirmi.Z.a stricta BM, WT PrimuZ.a tschu.ktscJiorwn VA, HS, IU, PinguicuZ.a viZ.Z.osa OM, WT BM, OT PinguicuZ.a vuZ.garis VA, HS, IU, TrientaZ.is europaea HS, MT LO, BM, OT UtricuZ.aria vuZ.garis IU, AQ PLUMBAGINACEAE RUBIACEAE Armeria mariti�a OM, VA, HS, IU, LO, LF, OT GaZ.iwn boreaZ.e HS, IU, OT GaZ.iwn Brandegei HS, IU, WT GENTIANACEAE CAPRI FOLIACEAE Gentiana gZ.auca VA, HS, IU, BM, MT Gentiana propinqua OM, VA, HS, IU, Linnaea boreaZ.is VA, HS LO, LF, BM Gentiana prostrata VA, HS, IU VALERIANACEAE Lomatogoniwn rotatwn OM, WT VaZ.eriana capitata OM, VA, HS, POLEMONIACEAE IU, LO, BM, MT, ST Phlox sibirica LO, OT CAMPANULACEAE PoZ.emoniwn acutifZ.orwn OM, VA, HS, IU, LO, WT Campanuia l,asioaarpa OM, VA, HS , IU, LO, LF, BM, OT BORAGINACEAE CampanuZ.a uniflora OM, VA, HS, IU, LO, BM, OT Eritrichiwn Chamissonis BM Mertensia panicuZ.ata VA, IU, ST COMPOSITAE Myosotis aZ.pestris OM, OT AchiZ.Z.ea sibirica HS (ekr) SCROPHULARIACEAE Antennaria Friesiana ssp. compacta LO, OT (ekr) CastiZ.Z.eja ca:udata VA, HS, IU, LO, LF, Antennaria Friesiana ssp. Frie­ BM siana VA, HS, IU, OT CastiZ.Z.eja eZegans BM, OT Antennaria monocephaZ.a IU, BM, PedicuZ.aris capitata VA, BM, OT OT Lagotis gZ.auca OM, VA, HS, IU, LO, Amica frigida OM, VA, HS, IU, BM, MT, OT LO, LF, BM, OT PedicuZ.aris Z.abradorica VA, OT Amica Lessingii HS, BM, OT PedicuZ.aris Z.anata OM, VA, HS, IU, Artemisia arctiaa HS, IU, BM, LO, LF, BM, MT, OT OT PedicuZ.aris Langsdorffii VA, HS, IU, Artemisia gZ.omerata LO, OT (ekr) LO, OT Artemisia senjavinensis LO, OT 56 TABLE 3. Continued .

Artemisia Tilesiii OM, VA, HS, OT Aster sibirious OM, VA, HS, IU, LO, LF, OT Chrysanthemum arotioum OM, WT, OT Chrysanthemum bipinnatum OM, OT Chrysanthemum integrifolium LO, OT Erigeron hwnilis VA, OT Erigeron hyperboreus LO, OT (ekr) Erigeron purpuratus IU, OT (ekr) Petasites frigidus DM, VA, HS, IU, LO, LF, BM, WT, MT Petasites hyperboreus VA, MT Saussurea angustifolia OM, VA, HS, IU, LD, LF, BM, MT, DT Saussurea nuda DM, WT Seneoio atropurpureus ssp. atropurpureus BM, DT Seneoio atropurpureus ssp. frigidus OM, VA, HS, IU, LD, LF, BM, MT, DT Seneoio atropurpureus ssp. tomentosus BM, OT (ekr) Seneoio oongestus OM, VA, HS, IU, WT, AQ Seneoio oonte:rrminus VA, OT (ekr) Seneoio fusoatus VA, DT (ekr) Seneoio Zugens VA, HS, IU, LF, BM, OT Seneoio pauperoulus IU, OT (ekr) Seneoio Pseudo-Arnioa OM, OT Seneoio yukonensis IU, WT (ekr) Solid.ago multiradiata DM, VA, HS, IU, LO, LF, BM, OT Taraxaoum alaskanum DM, VA, HS, IU, LD, LF, OT Taraxacum kamtsohaticwn DM, IU Taraxacum phymatooarpum VA Tripleurosperrrrum phaeooephalum DM, VA, LF 57 TABLE 4. Lichens collected in the Chukchi-Imuruk area in 1973. Nomenclature follows Hale and Culberson (1970) except where a taxonomic authority is qiven.

LOCATION CODES C� = Cape Espenberg LJ = Lost Jim Lava Flow

HD = Harris Dome LL = Lava Lake IL = Imuruk Lake SH= Serpentine Hot Springs

PELTIGERACEA E CZadonia unciaZis SH CZadonia verticiZZata LJ PeZtigera aphthosa LJ UMBILICARIACEAE NEPHROMATACEAE UmbiZicaria arctica LJ Nep71:!'oma arcticwn CE UmbiZicaria caroZiniana LJ Nep71:!'oma beUwn LL UmbiZicaria hyperborea SH UmbiZicaria mammu.Zata SH STICTACEAE UmbiZicaria veZZea LJ Lobaria Zinita LJ LECANORACEAE LECIDEACEAE Oc71:!'oZechia frigid.a SH Lecidia rubiformis LJ PARMELIACEAE STEREOCAULACEAE Asahinea chrysantha. LJ Cetraria cucu.Zlata LL StereocauZon pascha.Ze SH Cetraria DeZisei CE Cetraria cf. hepatizon IL CLADONIACEAE Cetraria isZandica CE, LJ Cetraria nigricans LJ CZadina abberans SH Cetraria nivalis CE, LJ CZadina aZpestris LJ Cetraria pinastri LL CZadina ar'bu.scuZa SH Cetraria TiZesii HD CZadina impexa Hypogyrrmia Bitteri LJ CZadina rangiferina LJ Hypogyrrmia physodes LJ CZadonia beZZidifiora SH Parmelia aZpicoZa SH CZadonia Boryi LJ ParmeZia centrifuga LJ CZadonia deformis LJ ParmeZia disjuncta LJ CZadonia gonecha. SH ParmeZia orrrpha.Zodes LJ CZadonia graciZis LJ, IL ParmeZia sa.xatiZis LJ CZadonia Zepidota LJ ParmeZia separata LJ CZadonia macrophyZZa LJ ParmeZia stygia LJ, SH CZadonia mateocyatha. LJ CZadonia metacoraZZifera LJ USNEACEAE CZadonia pZeurota LJ, SH CZadonia subfurcata SH AZectoria nigricans LJ, CE 58

TABLE 4. Continued.

Aleatoria oah.roleuaa LJ Aleatoria pubesaens SH Daatylina aratica SH Thamnolia subuliformis CE Thamnolia vermiaularis CE PHYSCIACEAE Anaptychia bryorum Poelt. LJ Physcia cf. ailiata var. deliaatula LJ Physaia saiastra LJ TELOSCHISTACEAE Xanthoria candelaria LJ SPHAEROPHORACEAE Sphaerophorus fragilis LJ, IL Sphaerophorus globosus LJ, IL 59 White spruce also appears to be more widespread than previously reported (Colinvaux, 1967}, growing on slopes in the eastern part of the study area and along rivers in the south. It occurs along the upper Kugruk, Koyuk and Fish River drainages within 10 to 20 km of Imuruk Lake (Fig. 1).

Erect paper birches (Betul.a papyrifem ssp.11 humitis) were seen locally on the Lost Jim Lava Flow, where the 11 trees were about 2 m tall. Brina Kessel {pers. comm.) told of multistenmed birch trees about 6 m tall in McCarthy Marsh in the southern interior of the study area. Feltleaf willow (Saik a'lazensis), normally a tall shrub, extends along the Serpentine River even farther north than alder on the Espenberg coastal plain. It appears that the cool-maritime climatic influence is strongest in the northwestern part of the study area, but there may be ameliorating changes in the climate there. PART II. VEGETATION Background The vegetation of the Chukchi-Imuruk area and surrounding region has been called shrub tundra, hypoarctic tundra, subarctic tundra (Polunin, 1955) and Zone I tundra (Young, 1971). Shrubs are more important in this kind of tundra vegetation than in herbaceous tundra vegetations, more arctic in character, that lie to the west on the Seward Peninsula1 , to the southwest on St. Lawrence Isiand (Young, 1971), and along the arctic coastal plain (Britton, 1967). Sedge and cottongrass (Eriophorwn and Care:r: spp.) tussocks and frequent thickets of willows, alders or shrub birches (Satix, Atnus or Betuia spp.) are distinctive features of shrub tundra landscapes. In Alaska, less atten­ tion has been paid shrub tundra than the herb tundra of the arctic coastal plain (Bliss et ai., 1973). The earliest references and photographs of Seward Peninsula vegetation were made by early geological survey personnel (Moffit, 1905; Collier, 1908). The first detailed floristic and vegetation studies were done in conjunction with reindeer range surveys by the Porsild brothers (Porsild, 1939) and Palmer and Rouse (1945}. These studies were mostly near Nome south of the Chukchi­ Imuruk area. Further reindeer range-oriented description and classification of Seward Peninsula vegetation was done by Hanson (1953) and Pegau (1968). Hanson recognized six physiognomic vegetation categories containing 22 types based on constituent species. These included three forest, five shrub, five dwarf shrub, one dwarf shrub-marsh, two herb-dwarf shrub, and six herb types. Pegau

1 Hopkins, D. M. 1973. Plant zonation and patterned ground near Bering Strait. Unpublished memorandum to members of the Beringian Study Group. U.S. Geol. Survey, Menlo Park, California. 2 pp. 60 1 modified Hanson s classification slightly to embrace units identifiable from aircraft. He recognized three forest, four tall shrub-herb, four dwarf shrub, four grassland-forb, and three sedge-marsh types, plus one rock desert type. Hopkins and Sigafoos (1951) and Sigafoos (1951) made intensive geobotanical studies in the Imuruk-Lava Lakes area (Fig. 1) where they were concerned with relationships between frost action and vegetation in a pennafrost landscape. They concentrated on microtopographic variation in vegetation on flat and low-slope terrain where the ground is perennially frozen at depths of less than a meter, drainage is poor, and tussocks are the predominant plant growth form. Although the present concern is more with macro- and mesotopographic variation in vegetation than1 with microtopographic1 and cryopedogenic-related variation, parts of Hopkins s and Sigafoos s work are relevant here. They recognized three basic types of wet tundra vegetation, tussock-birch-heath, sedge sod, and willow-birch thicket. They found that colonization of frost scars in the very wet sedge sod type results in peat rings, tussock rings and tussock groups. In better drained areas, frost scars develop into tussock-birch-heath polygons. From our 1973 work and the recent observations of others it appears that the frozen ground-vegetation features investigated by Hopkins and Sigafoos are less abundant today and that frost action in general is less intensive, at least in the Chukchi-Imuruk area. This is discussed further under cottongrass tussock-dwarf shrub tundra, below. Holowaychuk and Smeck (this volume) discuss cryogenic soils and associated geomorphic features in the area. Hopkins (1949) described the creation and drainage of thaw lakes and ponds in the Imuruk Lake area. Drained lake basins of various ages and their particular vegetations are conspicuous features on the coastal plain of the Espenberg Peninsula (Fig. 29). Sigafoos (1951) described vegetation common on various frost-action features, such as pingos, ground-ice mounds, turf-banked terraces, and peat mounds. Primary and secondary plants were listed, but no quantitative sampling for determining species importances was done. Only Hanson (1951, 1953) provided sampling data with his descriptions of vegetation at various places in western Alaska, including stands near Nome and Kotzebue and, in the Chukchi-Imuruk area, near the head of the Kougarok River. As was noted in the general introduction, palaeobotanical evidence suggests that most of the Chukchi-Imuruk area has been treeless throughout the late Pleistocene, with the forest-tundra boundary fluctuating in and near the southeast corner during this Epoch (Fig. 1). Thus, the area may be viewed as part of a tension zone of interaction between forest and tundra vegetations. Boundary movements, roughly northwest-southeast, have probably occurred for at least 700,000 years (Table 5). Evidence for forest-tundra interactions is from a number of sites in and around the area; it includes plant macro­ fossils and microfossils, fossil ice wedges, and frost profiles (Fig. 1). Pollen grains, seeds, buried wood and even remnants of a whole forest are the principal components of fossil assemblages. Locations include Imuruk Lake (Colinvaux, 1964, 1967), Cape Deceit (Guthrie and Matthews, 1971; 61

TABLE 5. Some geobotanical conditions in the Chukchi-Imuruk area during the Quaternary Period.

INTERVAL REFERENCE years BP CLIMATIC and +a 1,000a VEGETATION DEVELOPMENTS CONDITIONS LOCATION

0.03 to expansion of alder and tall clearer and Hopkins present willow shrub thickets; sphagnum warmer summers 1972, development in tussock-dwarf Kuzitrin­ shrub tundra Kougarok River 10 to 8; expansion of paper birch, bal­ Thermal Maxi­ McCulloch early sam poplar, tall willow, and mum (first of and Hopkins Holocene possibly white spruce ranges two in Holocene 1966, on Seward Pen.)· Kougarok River 13 to l 0; dwarf birch increase; tussock­ warmer surm,ers Hopkins late Wiscon­ dwarf shrub tundra development; pers. comm. , sinan possible steppe tundra in places Cowpack Inlet; Col­ invaux 1964, Imuruk Lake; Matthews 1974, Cape Deceit 20 to 13; herb tundra, possibly steppe dry cold windy Colinvaux Wisconsinan tundra, with grasses, Artemisia winters, but 1974, and few shrubs less severe Imuruk Lake than I 11 i noi an around 100; white(?) spruce common below continental Hopkins Sangamonian 300 m 50 km west of present climate; mean 1972, Cow­ limit; alder abundant on upland annual tempera­ pack Inlet; sites ture <0 ° C Matthews 1974, Cape Deceit Illinoian low-arctic shrub tundra with cool maritime Colinvaux r.igh dwarf birch content chang­ changing to 1964, ing to arctic herb tundra cold continental Imuruk Lake climate; Bendel­ eben Mts. gla­ ciers much ex­ tended; loess de­ position 62 TABLE 5. Continued.

INTERVAL REFERENCE years BP CLIMATIC and f l,QQQ VEGETATION DEVELOPMENTS CONDITIONS LOCATION pre-Illinoian some spruce in the area boreal or sub­ Colinvaux arctic climate 1964, Imuruk Lake 700 to 600 forest-tundra vegetation fea­ boreal climate Hopkins and (an earlier turing Laru; spruce forest Benninghoff, inter­ with Botryahiwn (in different 1953, Kuzi­ glacial} places or alternating through trin and time} Kugruk R.; Matthews 1974, Cape Deceit 5,700; rich conifer forests on flood temperate or Hopkins et Pliocene plains cool-temperate al. 1971 , (pre-Quater­ climate Inmachuk nary) River 63 Matthews, 1974), Lava Camp-Inmachuk (Hopkins et aZ., 1971), Black Gulch­ Kougarok River-Coffee Creek lMcCulloch and Hopkins, 1966; Hopkins, 1963; Hopkins and Benninghoff, 1953), and Cowpack Inlet (D. M. Hopkins, pers. comm.). Matthews's (1974) work at Cape Deceit provides a comprehensive picture of whole-ecosystem changes during the Pleistocene. Although conditions in that coastal location may have been somewhat different from inland at Imuruk Lake, there is evidence at both places that tundra vegetation has persisted through­ out the past 400,000 years. During most of this time shrub tundra vegetation was absent, in contrast to today. During the Illinoian an herbaceous tundra similar to that now in the arctic at Barrow became prevalent (Table 5). In the Wisconsinan a steppe-tundra with Poa, Artemisia and PotentiZZa species appar­ ently developed under cold and dry continental climatic conditions. The several shrub tundra vegetations of today began to develop around 12,000 years ago. Similar vegetations and woodlands appear to have developed during ear­ lier interglacial ages. Matthews showed that whereas the spruce line may have been several kilometers farther west than now during the Sangamonian and Holocene, it is only for the pre-Illinoian interglacial, some 400,000 years ago, and earlier interglacials that there is strong evidence for open forest or forest-tundra (woodland) as far north as Deering. Much of the Holocene history of the Chukchi-Imuruk area, i.e. of the past 8,000 to 10,000 years, has not been determined. Analysis of a core from Whitefish Lake and of future cores from Espenberg maar lakes may provide information about this epoch.2 Methods The vegetation study involved extensive qualitative observations and quan­ titative sampling of 44 stands (_Appendix I). In the interior uplands, stands were located along local topographic gradients, from valley bottoms and footslopes to nearby summits or ridge crests. Stands on beaches and lava flows were also sampled. Holowaychuk and Smeck (this volume) sampled soils in some of the same places, thereby facilitating the relating of vegetations and soils. As many kinds of sites as possible were visited in order to sample adequately the vegetation diversity in the study area. Sampling employed a quadrat technique devised by P. J. Webber (pers. comm.). A strip of ten meter-square quadrats was laid out in a stand. Species pre­ sence was noted in each quadrat, and percent cover was estimated for species in a tenth-meter strip along one side of each quadrat. Relative cover and relative frequency were calculated and combined for an importance value for each species in a stand. A matrix of importance values was constructed and used for ordination accord­ ing to the technique of stand-defined axes of Swann, Dix and Wehrhann (1969).

2Hopkins, D. M., P.a A. Colinvaux and D. A. Livingstone. 1974. Reconnaissance of large lakes in the proposed Imuruk-Chukchi wildlands to consider the pos­ sibility and desirability of lifting long cores. Unpublished report, U.S. Geol. Survey, Menlo Park, California. 28 pp. 64

TABLE 6. The 20 vegetation types and the physiographic positions where they occur most frequently• COASTAL REGION VOLCANIC ASH REGION LAVA REGION "' "'

"'s...... a .i:: .... "' Qj Qj .... ::, C ..... Qj .... u QI ..... ,- ,- ::, u ...... s.. C. "' .a C. = '° C .c: .c: "' � "' -0 CJ (lJ '+- ... C: .c: � (lJ '+- <11 :::, u u (lJ "' +-' 0 � 0...... ,:::: "' u "' 0.. C: "' C: E u "' 0 0 0 "' � � .,, "' u 0 "' 0 � (lJ (lJ 0 "' .... .c: E 0 :::, 0 "' <11 "' E 0 +-' co co Cl LU u.. u.. Vl Vl Vl (/) (/) t- co co w Vl Vl Vl (/) FORESTS ANO WOODLANDS 1.e White Spruce Foreste ------X ------X ------2.e White Spruce Woodlande - -- - 3.e Balsam Poplar Foreste ------X - -- - SHRUB THICKETS 4.e Balsam Poplar Shrub Thickete --- - X- -X - X - 5.e Tall Willow Shrub Thickete - - X - 6.eLow-Medium Willow �hrube X - X - - - X - - X X - - - X X Thickete 7.e Green Alder Shrub Thickete - - X - X - TUSSOCK-DWARF SHRUB TUNDRA - 8. Cottongrass Tussock-Dwarfe - - X - X - Shrub Tundra - - 9.eCottongrass-Bigelow's Sedgee - X - X - Tussock-Dwarf Shrub Tundra -- 10.e Bigelow's Sedge Tussock­ X X X - - Dwarf Shrub Tundra DWARF SHRUB TUNDRA X - 11.e Oryas Dwarf Shrub Tundrae - X - X - -- X- X - X X------X X 12.e Lichen Dwarf Shrub Tundrae X 13.e Bigelow's Sedge Dwarf Shrube - - X - X X -- X - X - X Tundrae 14.e Birch Dwarf Shrub Tundrae X - - - X X X - - - X - X ROCK DESERTS X - - X X - - - X - X X - - - X X MEADOWS X ------15.eElymu.s Cll'enarius Meadowe 16.e Saltgrass Meadowe 17.e Bluejoint Meadowe X ------X 18.e Tall Cottongrass Wet Meadowe X - - X - X - X - - - X - X - 19.e Water Sedge Wet Meadowe -----X - X - X - 20.eAquatic Meadowse 66 This ordination in conjunction with investigator judgement was the basis for establishing the vegetation types outlined below (Table 6). In addition, two sets of stands were ordinated using McIntosh's (1972) method based on leading dominants. The results of this permitted a closer examination of shifting species dominance among stands within physiognomic classes. Results - Outline of the Vegetation Types The six primary classes of the study area vegetation are physiognomic, being based on structure (height, spacing and stratification) and growth forms of the most conspicuous, or dominant, plants. The vegetation types are broad floristic subdivisions of these classes designated by the dominant taxa. Table 6 surmnarizes the classification and shows the physiographic distribu­ tion of the types. Table 7 lists observed correspondences between vegetations and soils•

TABLE 7. Correspondence between soil types and vegetation types in the Chukchi-Imuruk area.

Soi 1 Type* Vegetation Type

A.e Histic Pergelic Cryaquepts (Meadow tundra)e Cottongrass tussock-dwarf shrub tundra B.e Histic Pergelic Cryaquepts (Half-bog)e Water sedge wet meadow (on solifluction terrace) C.e Pergelic Cryofibrists (Bog)e Water sedge wet meadow D.e Pergelic Cryaquepts {Upland tundra)e Bigelow's sedge dwarf shrub tundra A-D.Transitional between A and De Water sedge tussock-dwarf shrub tundra E.e Lithic Cryorthodse Lichen dwarf shrub tundra F • Pergelic Cryumbreptseor Cryochrepts Dryas dwarf shrub tundra (Arctic Brown)e G.e Pergelic Cryochrepts (Arctic Brown)e Lichen dwarf shrub tundra H. Typic Cryoquents or Cryofluents Tall and low-medium willow shrub thickets

*See Holowaychuk and Smeck (this volume) for descriptions.e 67 Forests and Woodlands 1. White Spruce Forest - Forests dominated by white spruce (Piaea gl.auaa) 9 to 11 m tall form moderately dense stands on river flats in meanders of the Fish River (Fig. 1). Individual trees reach 33 to 46 cm in diameter (at breast height) and in 1973 supported a rather large cone crop (B. Kessel, pers. comm.). There is a thick ground cover of mosses in most stands. White spruce forests appear as river islands and stringers in the landscape. 2. White Spruce Woodland - White spruce is also dominant in woodlands on hillsides and river slopes along the southern border of McCarthy Marsh and along tributaries of the Kugruk River 10 to 20 km east of Imuruk Lake. As viewed from the air the Kugruk River stands comprise scattered white spruce, a closed shrub layer of alders, willows or shrub birches, and occasional bare or lichen-covered patches of ground. Spruce woodlands also occur south­ east of Imuruk Lake on the upper Koyuk River. 3. Balsam Poplar Forest - Stands dominated by balsam poplar (Populus balsCJJ11- ifera) in more or less closed-canopy arrangement are prominent on river flats in McCarthy Marsh, the Noxapaga-Kuzitrin River drainage and along American Creek (Fig. 2). Large balsam poplars also grow at Pilgrim Hot Springs west of the study area. On American Creek balsam poplar stands contain from 50 to 100 trees reaching heights of 9 to 11 m and diameters of 30 to 38 cm (Fig. 3). Stands on bends of the Kuzitrin and Noxapaga Rivers contain 15 to 20 trees 6 to 8 m tall and up to 20 cm in diameter. Here feltleaf willow (Salix alax­ ensis) forms an understory. In Figure 2 the three southern Pb symbols indi­ cate balsam poplar forests, while those in the north indicate balsam poplar shrub thickets. Shrub Thickets Thickets dominated by shrubs l to 5 m tall occur throughout the study area, mostly along streams, in drainageways, and on steep bluffs around lakes. Average shrub height in thickets varies according to topographic position and distance from the northern coast. In general, it increases with more favorable local climates farther from the Chukchi Sea and with the protection afforded by stream banks or other slopes. On the Espenberg Peninsula shrub thickets are seldom above 1.2 min height, but inland along the Inmachuk River they reach 6 m. Shrub thickets occupy a significant portion of the study area. Around Imuruk Lake approximately 20 percent of the terrain is covered by shrub thickets, and an inlet of the lake is named Salix Bay. Disturbances created by mining, such as ditching and dredging, have probably furthered the development of shrub thickets. 4. Balsam Poplar Shrub Thicket - Balsam poplars as tall shrubs or small trees form thickets or groves of restricted occurrence in the study area. North of Imuruk Lake there are several isolated stands, and on steep dry slopes along the upper Inmachuk River there are groups of 30 to 50 balsam poplars up to 4.6 min height and 15 cm in diameter. In two stands on the upper Inmachuk River about 37 km south of Deering, balsam poplars formed an open overstory with an understory of Arctostaphylos alpina, A. Uva-Ursi, Mertensia panicu- 68

Figure 3. Semiwooded landscape in the vicinity of American Creek in the southwest corner of the Chukchi-Imuruk area. In the middle distance are small stands of balsam poplar forest. The closer, more extensive vegetation is mostly a low-medium willow shrub thicket. The white bloom speckled plant cover in the fore­ ground is cottongrass tussock-dwarf shrub tundra. Photo by B. Kessel. lata., Potentilla fruticosa., Salix glauca and Zygadenus elegans. In August 1973 the balsam poplars in one stand bore many catkins, and there were numerous root sprouts. A stem 4.5 cm in diameter was about 42 years old. The presence of A. Uva-Ursi far to the west of its main range only in these balsam poplar stands suggests that they might be relicts from a time of more favorable climate. At Serpentine Hot Springs a balsam poplar grove of approximately 80 trees up to 3.6 m tall has probably been reduced in size by visitors cutting for firewood. These hot springs trees did not have catkins. Soil temperatures at 10 cm depth in this grove were 10 to ll°C in contrast with 8.5 to 9.5°C in nearby willow thickets, 4.5°C in tussock tundra, and 20 to 30°C in the immediate vicinity of the springs. 5. Tall Willow Shrub Thicket - Most tall willow shrub thickets are dominated by feltleaf willows 2 to 6 min height. Although individual feltleaf willows can be found almost anywhere from the Espenberg coastal plain to the Bendeleben Mountains, well developed thickets are limited to gravel bars along the 69 larger rivers and to protected drainageways where thawed ground is deep. Occasional small groups occur near streams on the Espenberg Peninsula. The best developed thickets were found along the Inmachuk River 37 km south of Deering where feltleaf willows reach 6 min height and 25 cm in diameter. On the coastal plain a small felfleaf willow shrub thicket on the Espenberg River contains shrubs up to 3.5 m tall. In deep ravines cut into the volcanic ash around Devil Mountain Lake feltleaf willows attain heights of 6 m and are mixed with green alder LAlnus arispa) and Richardson willow (Salix lanata ssp. Riaha.rdsonii). The latter species dominates in occasional tall willow shrub thickets. Tall willow shrub thickets similar to those in the Chukchi-Imuruk area occur on gravel bars throughout Alaska, even north of the Brooks Range along the Colville River (Bliss and Cantlon, 1957) and at Ogotoruk Creek (Johnson et al., 1966). 6. Low-Medium Willow Shrub Thicket - This is the most extensive shrub thicket type, covering large areas in small drainageways on slopes, on stream banks and on steep scarps around lakes and ponds. Low-medium willow shrub thickets are a most distinctive feature in the study area landscape. Willows, normally l to 2 m tall, include grayleaf willow (Salix ~Z.auaa), Richardson willow, and diamondleaf willow (S. pl.anifolia ssp. pulahra). In places, low-medium willow shrub thickets cover sloping areas. On more level terrain willows may form open stands or patches alternating with small bluejoint (Calamagrostis aanadensis) meadows in a mosaic. This is especially common in old drained lake basins on the Espenberg Peninsula. Even where the willows are dense a characteristic herbaceous understory develops with Anemone Riaha.rdsonii, Astragalus alpinus, bluejoint, Dodeaatheon frigidum, Equisetum spp., Ru.bus aratiau.s, Sa:r:ifraga punatata, Valeriana aapitata and Viola epipsila. Spiraea Beauverdiana is often present. Drainageways on gradual rounded slopes characteristic of the interior uplands are often streaked with low-medium willow shrub thickets. The willows become lower in stature upslope. At thicket edges there is an abrupt change to tussock-dwarf shrub vegetation (Fig. 4). Where water is excessive in a drain­ ageway a thicket may be interrupted by a wet meadow. Where willow shrub thickets occur on alluvial sites, the soils are Typic Cryaquents or Cryofluvents designated Soil H by Holowaychuk and Smeck (this volume). These are weakly developed because of frequent additions of fresh sediments during stream overflow. The upper portion of the profile is frozen during much of the year, but the soil is not underlain by continuous perma­ frost. 7. Green Alder Shrub Thicket - Thickets of green alder occur sporadically over the study area at lower elevations and are easily spotted as dark green patches in the landscape. Their absence above 300 mis conspicuous. Alder thickets are most corrrnon in the Espenberg volcanic ash area around the maar lakes, in the Inmachuk and upper Kugruk River drainages (the latter near white spruce woodland}, and in deep crevices on the Lost Jim Lava Flow. Although alder is common on the Espenberg Peninsula, it is not in the low coastal areas to the north and west. Alder thickets occur patchily on slopes, 70

Figure. 4. View up a broad shallow drainageway near Imuruk Lake. There is a very sharp boundary between the low-medium willow shrub thicket and the tussock-dwarf shrub tundra vegetation. as more extensive stands along rivers, and on cliffs on drier, less protected sites than are occupied by willow shrub thickets. Alder thickets are usually 1.5 to 2 m tall with a sparse herbaceous understory. In a few cases alder and diamondleaf willow or feltleaf willow form alder-willow shrub thickets. Tussock-Dwarf Shrub Tundra Tussock-dwarf shrub vegetation in the study area is dominated by the tussock­ forming graminoids cottongrass (Eriophorum vaginatwn), Bigelow's sedge (Car'e.r Bigelowii) or both and by various dwarf willows, ericads (Ericaceae) or dwarf birch (Betula nana,). Tussocks usually range between 20 and 60 cm both in ~iameter and height. Tussock-dwarf shrub vegetation is the most extensive 1 n the area, covering lower and middle slopes and flat uplands throughout most of the interior. The slopes supporting it are mostly less than 10 percent anct are poorly drained. On slopes steeper than 10 percent, there is dwarf shrub vegetation, and on very flat low-elevation surfaces with standing water 71 wet meadow vegetation predominates (see below). Tussock-dwarf shrub vege­ tation covers over 50 percent of the ground in the coastal volcanic ash and interior upland zones but is conspicuously absent from the Bendeleben Moun­ tains and the lava flow sites. In many places, but particularly on the coastal plain, tussock-dwarf shrub vegetation is associated with high-centered polygons (Figs. 5 and 6). Along the vegetation-soil transects in the upland regions of Imuruk Lake, the Inmachuk-Hannum River and Serpentine Hot Springs, tussock-dwarf shrub vegeta­ tion was mostly limited to the foot slopes (Fig. 7a, c, d). In contrast, around Devil Mountain Lake and elsewhere in the volcanic ash zone, tussock­ dwarf shrub vegetation occurred more often on the flatter upper parts of the normally convex slopes (Fig. 7b). Tussock-dwarf shrub tundra vegetation was associated with Soil A in most cases. This is the Meadow Tundra soil of Tedrow et al. (1958). In some stands the soils are transitional between A and D, the latter corresponding to the Upland Tundra type of Tedrow et al. Soil A is strongly acid and poorly drained with a moderately thick layer of organic material over gray or dark gray mottled, medium textured mineral subsoil.

Figure 5. Aerial view of terrain along the Espenberg River on the coastal plain featuring high-centered polygons. Tussock-dwarf shrub tundra vegetation occupies the polygon centers. 72

Figure 6. Espenberg Coastal Plain tundra landscape. Most of the view is occupied by tussocks on the elevated centers of polygons. In the right foreground is a segment of a polygon trough containing wet meadow vegetation.

There are usually two to four tussocks per square meter (Fig. 8) for around 20 percent of the plant cover. The spaces between them are occupied by dwarf shrubs providing much of the rest of the cover. Despite a frequently higher dwarf shrub cover, the tussock growth form is the more conspicuous in this vegetation. Labrador tea (Ledwn palustre) is usually the most important dwarf shrub with around 11 percent cover. Other important dwarf shrubs and their percent cover values are dwarf birch 8, crowberry (Empetrwn nigrwn) 5, cloud­ berry (Rubus chamaemorus) 8, bog blueberry (Vaccinium uliginosum) 5, and lingonberry (V. Vitis-Idaea) 9. Sphagnum mosses are locally abundant between the tussocks. Lichen cover is usually lower relative to mosses than in dwarf shrub vegetation (below). Common lichens include Cetraria cucuZZata, C. isZandica, Cladina rangiferina, Cladonia gracilis and Thamnolia subuliformis. Tussock-dwarf shrub vegetation is widespread in the southern Arctic in places Where herbaceous plants alone are prevalent. It is common on the Seward Peninsula, although it decreases westward and is absent from St. Lawrence Island. Tussock-dwarf shrub vegetation covers 40 percent of the terrain in 71

150 I 50------.

100 A. lmuruk • Nimrod 100 8 Devil Mtn. Lakes back slope so•ot�west 'I nor: �east west east 50 ) : 50 r,/)... Q) 0 ...... � Q) 8 12 16 20 24 28 16 12 8 4 0 E

C 250 ' 0 ' Serpentine - upland 0. > Hot Springs tor � 200 w backslape

Q) > 150 0 west east we,t

100

east SO C. I nmachuk- Hannum River

0 ______.._....__.__....__....._..__ ...... __...... __._.....,_ 32 28 24 20 16 12 8 4 0 16 12 8 4 0 Horizontal Distance ( 1oo·s of meters)

Figure 7. Distribution of tussock-dwarf shrub vegetation on slopes at four locations in the Chukchi-Imuruk area. Samples of soil and vege­ tation were taken at sites indicated by a dot. the Ogotoruk Creek watershed where associated frost features are frequent (Holowaychuk et aZ., 1966; Johnson et aZ., 1966). 8.t Cottongrass Tussock-Dwarf Shrub Tundra - This type is very extensive ont lower slopes in the interior uplands and on flats and slopes of less thant around five percent in the volcanic ash region. On the generally wet coastalt plain it occurs on better drained low hills, ridges and lake margins. 1 Cotton­ grass tussocks are dominant only on Soil A. A few tussocks of Bigelowts sedget are usually present. Since this is the wettest of the three tussock-dwarft shrub vegetation types, tall cottongrass CEriophorwn angustifoZium) is fre­ quently present, particularly where there are frost scars. In the troughs bordering high-centered polygons (Fig. 6) the sedge and sphagna are important.1 Bog blueberry tends to be less important in this type than in the Bigelowtst sedge tussock-dwarf shrub vegetation (below).t 9.t Cottongrass-Bigelow's Sedge Tussock-Dwarf Shrub Tundra - Mixed tussock­ dwarf shrub vegetation occurs on slightly steepe1 r slopes than the preceding type. Tussocks of cottongrass and Bigelowts sedge usually appear randomly interspersed. However, in a stand near Lava Lake the distribution of thet 74

0 Oworl s,,.,.oeo,,.,,,1.0 5 • Figure 8. Characteristics of tussock-dwarf Q E:.=,,.> Cdn• shrub undra related to slope. 0 0 : :.;C-•>E,,_,,,,, t 0 I Each circle represents a sample; Oo o: diameter indicates the ratio of _____ Q_!------dwarf shrub cover to tussock cover. �•Cf': (-.. � Circles with solid lines indicate , ..� .• .. , .. I the cover of E:t"'�oph�r".mt vagina� exceeded the cover of Ca:t'e:r: Bigelo�ii; 0 dashed circles indicate the inverse. 0 2 4 6 8 10 12 14 16 SIOl)e (%) two tussock species was found to be nonrandom. !There were distinct groups of around 14 cottongrass tussocks in a matrix of sedge tussocks. These groups made about 28 percent of the cover, and bare ground between the group tussocks accounted for another 20 percent. Small cottongrass seedlings were present in the inter-tussock bare places. Hopkins and Sigafoos (1951) showed how cottongrass tussock groups are related to frost action in the Imuruk Lake area. 1 10. Bigelow s Sedge Tussock-Dwarf Shrub Tundra - This type is represented on better drained parts of slopes, frequently where S-shaped slopes steepen upward to about ten percent. Since Bigelow's sedge normally does not form tussocks on better drained sites, on these steeper slopes this type grades into dwarf shrub vegetation with sedges of nontussock form. Thus dwarf shrubs, especially bog blueberry and dwarf birch, are more important in this vegeta­ tion type than in the other two tussock-dwarf shrub types. In places tr,e aforementioned dwarf shrubs are dominant. 1 Bigelow s sedge tussock-dwarf shrub vegetation occurs on soils different from those of the other two tussock-dwarf shrub types. The sedge dominates on Soil Dor, more often, on soils intennediate bet1.

Axis l 75 method based on leading dominants, further illustrates differential domin­ ance of these and certain other species. Importance values are given in Table 8.

TABLE 8. Importance values of species in tussock-dwarf shrub tundra stands. See Figure 9.

Species 1 3 4 5 6 8 9 10 11 12 13 14 l 5 HERBS Carex aquatiiis 00 00 00 00 01 00 00 02 00 00 15 21 06 Carex Bigelowii 49 17 14 19 26 22 23 21 12 31 00 02 05 Eriophorum angustifolium 00 00 22 00 00 00 00 02 04 03 14 00 00 Eriophorwn vaginatum 08 23 32 45 00 00 00 00 23 38 33 23 34 Petasites frigid.us 06 00 00 05 00 10 07 00 00 00 00 00 00 Ru.bus chaJrlaemorus 12 05 06 05 25 06 22 12 17 11 23 05 18 DWARF SHRUBS A:l'ctostaphylos alpina 03 00 10 05 00 00 12 00 00 00 00 00 00 Betuia nana 17 31 22 17 21 20 28 13 17 17 17 25 17 Empetrwn nig-rum 13 11 04 09 04 15 13 12 04 07 10 00 08 Ledwn palustre 14 25 20 21 24 16 22 24 31 29 19 18 23 Salix planifolia ssp. 08 03 00 08 02 13 03 02 06 00 00 00 00 pulch.ra Vaccinium uliginosum 07 08 04 21 11 32 09 33 19 02 23 29 22 Vaccinium Vitis-Idaea 16 23 18 19 28 18 19 10 22 19 17 10 13 LICHENS 02 06 05 16 18 22 14 05 11 16 10 07 07 MOSSES (exc. Sphagnum) 27 16 00 08 16 00 09 09 16 11 06 03 11 Sphagnum spp. 00 16 20 03 25 06 05 32 09 12 14 32 16 BARE GROUND 00 00 31 00 00 00 00 00 00 00 09 08 10

Changes in Tussock-Dwarf Shrub Tundra The Lava Lake site, where there are cottongrass tussock groups (see type 8 above), is important because it is one of the few places where in 1973 we observed one of the frost action-influenced vegetation types which Hopkins 76 3 and Sigafoos (1951)e described as a conspicuous feature in the landscape. The present scarcity of this type indicates considerable change since the 1ate 1940's. Frost heaving seems to have become less frequent. Indeed, it was difficu1t to find fresh unvegetated frost scars in 1973. In many places the inter-tussock ho11ows were filling in with sphagnum mosses so as to destroy the individuality of the tussocks, and in some places dense patches of c1oud­ berry had become established on the new sphagnum substrate. This filling in by sphagna was most common in stands of the cottongrass tussock-dwarf shrub vegetation type wherein the tussocks now are moribund or dead.

A consequence of reduced frost action and vegetation 1 mat buildup is a shal- 1ower permafrost tab1e in 1973 than in the 1ate 1940es (Hopkins and Sigafoos, 1951). Depths to pennafrost were measured in tussock-dwarf shrub vegetation throughout the 1973 season at each camp (.Table 9). These measurements show increases from around 20 cm to about 40 cm in thaw layer thickness between early July and August. Hopkins and Sigafoos noted that in tussock-birch­ heath vegetation, depths to perennially frozen ground ranged from 38 to 91 cm, averaging 75 cm. Hopkins (1972) reported an active layer thickness of about 45 cm in a fossil tussock-dwarf shrub vegetation soil profile buried by ash 10,000 to 13,000 years ago. A reduction in frost action seems to lead first to deeper thawing and better drained soils. As such, substrate conditions are more stable and conducive to plant growth, especially sphagnum buildup in the moist inter-tussock11 hollows. This process may lead to a slope muskeg or 11 hochmoor (see foot- note 2) with a thick and continuous insulating vegetation mat and, consequently, sha11ower permafrost and more restricted drainage than before.

Causes of the initial reduction in frost action are not very well known. 1 Hopkins (footnote 2) recognized wanner and drier summers during the 1950es and 1960's as a likely factor. Changes in the tundra fire regime and rein­ deer grazing pattern may also be involved. If a warmer climate is respon­ sible, it is especially interesting to note the decrease in thaw layer thick­ ness. Dwarf Shrub Tundra Dwarf shrub tundra vegetation is dominated by shrubs less than l m high, more or less prostrate and variously spreading, matted, clumped or cushion-like. Nontussock sedges or grasses and lichens are important in some dwarf shrub tundra stands. Stands with a considerable amount of bare ground are tran­ sitional to units in the rock desert category (below). Dwarf shrub vege­ tation is prevalent on well drained and often rocky, sandy, volcanic ash or lava substrates. It occurs in all five physiographic regions and is especially important in the mountains and uplands, on the lava plateau, and

3 Also, Hopkins, D. M. 1973. Effects of large scale burning on cottongrass tund�a on Seward Peninsula: a research imperative. Unpublished memorandum to members of the Beringian Study Group. U.S. Geol. Survey, Menlo Park, California. 3 pp. 77 TABLE 9. Depth to frozen ground in tussock-dwarf shrub tundra (T-DST) and dwarf �hrub tundra (DST} stands in the Chukchi-Imuruk area in 1973.

Mean Depth Date Location Vegetation Type N l cm SD2 June 28 N Killeak Bigelow's sedge T-DST 7 17. 1 4.5 Lake July 7 Lava Lake Bigelow's sedge T-DST 40 23.0 6.2 1 July 12 Lava Lake Cottongrass-Bigelow s 20 26. 1 6.5 sedge T-DST r July 13 Imuruk Lake Cottongrass T-DST 20 27.6 10.0 I July 13 Imuruk Lake Cottongrass-Bi gelow s 20 24.5 5. la sedge T-DST July 14 Imuruk Lake Cottongrass-Bigelow's5 21 21. 9 3.8 sedge T-OST July 14 Imuruk Lake Bigelow's sedge DST� 10 23.5 2.9 July 14 Imuruk Lake Bigelow's sedge DSTa ' 10 24.6 5.7 July 14 Imuruk Lake Cottongrass T-DST 10 29.3 7.5 August 3 Serpentine Bigelow's sedge T-DST 10 38.6 6.0 Hot Springs August 10 Serpentine Bigelow's sedge T-DST 11 30.7 5.0 Hot Springs

1Number of samples or depth probes. 2standard deviation in cm. on the Lost Jim Lava Flow (Table 6). The tussock-dwarf shrub tundra vege­ tation of gradual footslopes often grades into dwarf shrub vegetation upslope and on the crest or ridge (ftg. 10}. Dwarf shrub tundra vegetation occurs on a range of soil types designated by Holowaychuk and Smeck as Soils D, E, F and G. These are moderately well drained lSoil D) to well drained, and most are associated with frost features such as stone and mud stripes, circles and nets. Soils F and G were classi­ fied Arctic Brown Soils by Tedrow et aZ. (1958). Soil Eis a local ized type in pockets on the Lost Jim Lava Flow, and Soil D occurs on steep backslopes, 78

Figure 10. Landscape in the Serpentine Hot Springs area. The springs are in the left middle distance. Behind and on either side of the springs are granite tors. The foreground, on and near the broad crest of a slope, is covered mostly by dwarf shrub tundra vege­ tation. i.e. around 13 percent, in the uplands. In all soils except Soil D, perma­ frost is deep and temperatures are moderate. Dwarf shrub tundra vegetation is quite variable and includes the largest array of species of the six physiognomic classes. In the Chukchi-Imuruk area it was sampled along the coast on old beach ridges, on the volcanic ash areas around the Espenberg maar lakes, on the limestone domes, around the granite tors, on the summits of some interior upland slopes, on the lava flows, and in the Bendeleben Mountains. Across this wide range of locations there is much variation in leading dominants, as the special ordination of 18 dwarf shrub and related rock desert stands shows (Fig. 11; Table 10). Along axis l there is a shift in dominance from lichens to bare ground and dryas mats. Along axis 2 there is some shift toward dominance by various ericads. lL_ Dryas Dwarf Shrub Tundra - The stands on the right in the ordination space of Figure ll, in which plant cover is only around 50 percent, represent the dryas dwarf shrub tundra vegetation type (Fig. 12). Dryas integrifolia 79

@VV•\/U Figure 11 . Leading-dominant ordina­ tion of 18 dwarf shrub @VV•LP tundra and related rock @L·AA @CB·\/U desert stands showing @AA·BG N shifting dominance. "' @cs-BG >( Dominant species are AA= AI>atostaphyZos aZpina; BN=BetuZa nana; BG=bare ground; CB=Carex BigeZowii; D=Dryas spp.; EN=Empetrum Axis I nigrum; L=lichens; LP= Led.um paZustre; VU=Vaaain­ ium uZiginoswn; VV=V. Vitis-Idaea. TABLE 10. Importance values of species in dwarf shrub tundra stands. See Figure 11.

Stand Species 27 28 29 30 32 34 35 36 37 38 39 40 43 44 HERBS Carez BigeZowii 12 12 14 27 00 05 00 09 10 42 00 03 10 50 Anemone sp. 00 00 00 00 00 00 00 00 00 00 00 06 00 16 Pediau.Zaris sp. 07 04 02 04 00 00 00 00 00 00 00 00 00 00 PotentiZZa viZZosa 00 00 00 00 00 00 00 00 09 00 00 05 00 00 Silene aaaulis 00 00 00 00 00 00 00 00 11 00 07 05 00 00 DWARF SHRUBS Andromeda poZifolia 00 00 00 00 00 00 00 00 00 06 03 00 00 00 AI>atostaphylos alp�na 13 00 28 16 00 03 00 00 06 05 15 00 11 00 BetuZa nana 24 00 09 11 00 23 14 00 00 10 00 00 18 00 Cassiope tetragona 00 00 00 00 00 00 00 00 00 17 12 00 19 00 Diapensia lapponiaa 03 09 07 00 00 00 00 00 00 00 00 00 11 00 Dryas spp. 00 09 00 08 00 00 00 39 26 06 10 53 04 00 Empetrum nigrum 23 00 03 09 39 56 13 00 15 20 43 00 20 00 Ledum palustre 20 08 18 08 10 13 00 00 00 00 00 00 02 00 Loiseleuria proaumbens 05 17 08 00 00 00 00 00 07 00 30 00 00 00 Rh.ododend:t>on spp. 01 17 09 02 00 00 00 05 06 02 00 00 08 00 Salix phlebophylla 03 09 08 00 00 00 00 00 00 00 00 00 14 00 Salix retiaulata 00 00 00 00 00 00 00 00 00 07 07 09 00 00 Vaccinium uliginosum 31 00 24 18 26 03 19 16 05 15 15 00 08 00 Vaccinium Vitis-Idaea 32 07 16 11 22 26 31 00 05 01 00 00 00 38 LICHENS 17 29 30 12 76 48 53 22 08 05 00 23 06 75 MOSSES 10 00 00 08 15 00 11 00 00 10 00 05 00 00 BARE GROUND 00 66 03 08 00 15 28 43 57 26 53 43 71 00 80

Figure 12. Dryas dwarf shrub tundra vegetation on a gravelly ridge east of Imuruk Lake (foreground) and a stand of Deschampsia caespitosa occupying the surface of a ground squirrel burrow system. and D. octopetala are the type indicators. Secondary vascular species, of variable importance among stands, are Loiseleuria procumbens and lapponicwn on basic limestone and volcanic ash, and R. camtschatic?wn on acidic rocks; Cassiope tetragona., Diapensia Zapponica., PotentiZZa viZZosa., SaZi:c phlebophyZZa., s. reticuZata and Silene acauZis occur on a variety of sub­ strates (Table 10). Lichen cover is sparse and consists mostly of AZectoria spp. and OchroZechia frigida. There are frequently stripes or patches of gravelly ground alternating with vegetated places. Bog blueberry, dwarf birch, Labrador-tea and lingonberry, characteristic of tussock-dwarf shrub tundra types, are infrequent or absent. Crowberry, however, is important in some stands and may nearly replace dryas, particularly on volcanic ash or sandy beach sites. Dryas dwarf shrub tundra is well developed on the volcanic ash beaches west of several of the maar lakes. It usually develops in asso­ ciation with Soil F, an arctic brown soil as described by Holowaychuk and Smeck. 81 12. Lichen Dwarf Shrub Tundra - Where lichen cover is greatest and bare ground least in the ordination space of Figure 11 a lichen dwarf shrub tundra vegetation is recognized. Here lichens and dwarf shrubs have cover values of around 30 and 40 percent respectively. Stands of this type occur mostly on the Lost Jim and Camille Lava Flows, in ravines and lesser depressions where slightly podzolized Soil E has developed. Near Kuzitrin Lake a stand of lichen dwarf shrub tundra was on sandy Soil G. On the Lost Jim Lava Flow the dwarf shrubs bog blueberry, crowberry, dwarf birch, Labrador-tea and lingonberry grow in deep lichen mats on lower slopes and at the bottoms of the ravines and lesser depressions. The lichen mat is composed of fruticose species such as Cetra:l'ia islandiaa, c. nivalis, Cladina rangiferina, Cladonia alpestris, C. sylvatiaa and Stereocaulon paschale. Elsewhere on the Flow lichen mats develop in depressions and crevices with­ out dwarf shrub associates. Deep fissures up to 2 m wide and 10 m deep are moist and dark, and some have ice at the bottom. The mesophytic lichens Loba:l'ia linita, Peltigera aphthosa and Sphaerophoru.s fragilis grow on the walls and ledges. Green alder, willows and Spiraea Beauverdiana commonly grow as low shrubs near surface openings of the lava flow. Although the luxuriant lichen mats would seem important as winter forage for reindeer, local herders try to keep their animals away from the lava flows to prevent them from injuring themselves on the irregular surface (M. Karmun, Deering, pers. comm.). 13. Bigelow's Sedge Dwarf Shrub Tundra - This type is represented in the upper middle region of ordination space in Figure 11. Bigelow's sedge in nontussock form is diagnostic. Stands are fairly extensive on steep dry slopes of around 18 percent, on some old beaches, and in alpine regions of the Bendeleben Mountains. Many appear as rocky meadows (Fig. 13). Along slope gradients in the uplands, Bigelow's sedge dwarf shrub vegetation commonly occurs between the sedge tussock-dwarf shrub tundra of the lower slope and the dryas shrub tundra of the upper slope and crest. Thus, it is an intennediate type on the topographic-moisture gradient. Of the four dwarf shrub tundra types, this one occurs on the most moist sites, usually with a type D, or Upland Tundra, soil. The ground features hummocks and ridges, especially on steep slopes of around 20 percent. This type is further characterized by Arctostaphylos alpina. The other ericads Cassiope tetragona, Diapensia lapponiaa, Loiseleuria procwnbens and Rhododen­ dron camtsahatiaum are secondary, as are Salix phlebophylla and Oxytropis nigresaens. The dwarf shrubs in this list all indicate the close relationship of the type to dryas dwarf shrub tundra vegetation upslope from it. On the other hand the importance of Bigelow's sedge and the abundance of bog blue­ berry, crowberry, dwarf birch, Labrador-tea and lingonberry reflects an affinity with sedge tussock-dwarf shrub tundra lower on the slope. 14. Birch Dwarf Shrub Tundra - Dwarf birch can form dense thickets up to l m high. These occur throughout the study area as small and occasional big patches on drier sites, as on steep slopes, above steep banks, and in moun­ tain areas below solifluction lobes. Diamondleaf willow is secondary in some of these thickets. 82

Figure 13. View south to the Bendeleben Mountains from a rocky slope near Imuruk Lake. Much of the slope is occupied by Bigelow's sedge­ dwarf shrub tundra vegetation. Dwarf Shrub Tundra Across Maar Lake Beach Ridges There is an interesting arrangement of Bigelmv's sedge and dryas dv1arf shrub tundra vegetations and some of their species across beach ridges on the western shore of North Killeak Lake (Figs. 14, 15). This maar lake in the Es­ penberg volcanic ash area is rimmed on the west by a broad volcanic ash terrace with three clearly defined ridges representing old lake levels. Beginning at the shoreline there is a rim of volcanic ash perhaps pushed up by the spring ice pack. Back from this there is a series of small swells and depressions culminating in a second beach ridge about 40 m from the shore. About 100 m from the shore there is a third beach ridge, the prominent one in Figure 14.

Belt transects l m wide and 100 m long were established for vegetation sampling at two widely spaced places perpendicular to the shoreline. Presence and percent cover were recorded for each species in meter-square quadrats along the transects. In this way the distribution of certain species could be related to topographic position, distance from the lake and one another. 83

Figure 14. Volcanic ash terrace on the northwest side of North Killeak Lake. The elongate topographic feature extending away from the im­ mediate foreground is an old beach ridge. The light zone closer to the lake is a similar feature. The sequence of vegetations from the lake shore across the ridges and inter-ridge swales is described in the text and Figure 15. Figure 15 shows that several species are more or less restricted to certain segments of the transects. Elymus arenarius is only on the bare volcanic ash of the first beach ridge and the succeeding swells. The only other plants on the dark ash of the swells are Androsace septentrionalis~ Epilobiwn lati­ folium~ Equisetum scirpoides~ Festuca rubra~ Parrya nudicaulis~ Potentilla villosa and Stellaria monanth.a. In the swales between the swells there is a dwarf shrub cover of bog blueberry, crowberry, grayleaf willow and Rhododendron lapponicum. On the crest of the second beach ridge a dryas dwarf shrub tundra vegetation, featuring D. integrifolia, is well developed. Draba spp., Min­ uartia arctica~ Potentilla spp., and Silene acaulis also grow here. Immediately behind the second ridge there is a drop of two or three meters and a low thicket of grayleaf willows and occasional green alders. On the broad low flat between the second and third beach ridges there is Bigelow's sedge dwarf shrub tundra vegetation. Besides the sedge, Cassiope tetragona, dwarf birch and Lagotis glauca are characteristic of this inter-swell flora. Bog blue- 8_4_

I-Cl HJ C ~~E : CJ 3 00-0 0

vu --

~ Topographic Profile -- --- ~ I J cs•

EAi----- _J CD AA ,...- _I",- - _,... (.) CT Q.) -

Figure 15. Distribution of plant species along two (A and B) 100 m tran­ sects across beach ridges along the west shore of North Ki 11 eak Lake.

berry is important here, and Dryas integrifolia and crowberry are occasional. On the third ridge the dryas and crowberry are important along with EZymus arenarius and the other swell plants listed above. A similar ash beach with ridges is at North Devil Mountain Lake, but it is only sparsely vegetated. Hopkins et al. estimated this beach to be about 9,300 years old in contrast with at least 120,000 years for the beach at North Killeak Lake {Footnote 2). Rock Deserts

In this broad physiographic-physiognomic class plant cover is characteristically less than ten percent. Areas of such scanty cover are also called barrens, barren-ground tundra and fellfields. Holowaychuk and Smeck refer to them as fellfields 1'\1/here wind erosion and lack of moisture may account for the low plant cover.'1 There is little or no soil development. 85

Several rock desert areas were visited in 1973, but no samples were used in the general ordination. Second-level classes equivalent in rank to the other, numbered types were not distinguished.

On Harris Dome there are scattered mats and cushions of Artemisia senjavin­ ensis, Papaver vlalpolei, Parrya nudicaulis, Potentilla Vahliana, Sa,xifraga oppositifolia ssp. Smalliana and Salix 1°otundifolia ssp. Dodgeana (Fig. 16). The summit of Mt. Boyan at 920 m was covered with small dark boulders bearing Umbilicaria spp. between which were occasional plants of Hierochloe alpina, Luzula tundricola and Potentilla elegans (Fig. 17). Rock desert occupies a large portion of the youngest lava flows where only the ravines, draws and depressions are well vegetated. On the main surface, or the interfluves, of the Lost Jim Lava Flow nearly all the plant cover is of foliose and crustose lichens such as Lecanora spp., Parmelia saxatilis and orange splotches of Xanthoria candelaria. Other lichens in this austere setting are Asahinea chrysantha, Cetraria nigricans, Hypogymnia Bitteri, H. physodes, Parmelia centrifuga, P. disjuncta, P. omphalodes, P. separata, P.

Figure 16. Limestone dome landscape near the western boundary of the Chukchi-Imuruk area. The foreground is part of a rock desert on a dome slope featuring scattered patches of Salix rotundifolia spp. Dodgeana. 86

Figure 17. View from the summit of Mt. Boyan (920 m) in the Bendeleben Mountains where much of the landscape, as in the fore- and middlegrounds, is a rock desert. There is a considerable cover of lmbilicaria species and other dark colored rock lichens. stygia~ Umbil1~caria arctica~ U. caT·olinicma and L. vellea. The only vascular plants are those growing in crevices such as occasional individuals of Arnica frigida~ Saxifraga bronchialis and Selaginella sibirica. The older Camille (late Wisconsinan) and Gosling (Sangamonian and Wisconsinan) Lava Flows, with flat surfaces of frost-rived small angular stones, are about one third vege­ tated (Fig. 18). Other "deserts", or surfaces with little or no plant cover, include sandy and volcanic ash beaches adjacent to the ocean, and lake shores and gravel bars in rivers where E'pUobium Zatifol-ium forms sparse stands. 87

Figure 18. Rock desert vegetation with patches of dwarf shrub tundra on the Camille Lava Flow near Lava Lake. Meadows Meadows are dominated by graminoids, forbs or both. Dwarf shrubs and lichens are usually scarce or lacking. Meadows occur throughout the Chukchi-Imuruk area in all the physiographic regions. Dry, wet and aquatic meadows are recognized. Extensive dry meadows occur locally on well drained substrates such as coastal sand dunes, steep banks and scarps and on volcanic ash. Wet meadows are associated with flat, poorly drained terrain, as in low­ centered polygons, in drained lake basins, along lowland streams, at pond margins, and in the mountains on the tops of solifluction lobes and behind turf ridges. On some interior upland slopes, wet places occur at the bottom and on the broad flat summit. Soils under these poorly drained conditions are usually organic half bog or bog types described by Holowaychuk and Smeck as Soils Band C. 88

15. Elymus arenarius Meadow - The sea lymegrass, Elymus arenm~i,us, is locally dominant in dry meadows covering active sand dunes along the Chukchi Sea coast, inland on some gravel outwash flats, and on some volcanic ash beach ridges. Elymus meadows were best developed on the long wide strip of coastal sand dunes between Cape Prince of Wales and Cape Espenberg (Fig. 19). Coastal sand dunes are also common farther south on the Seward Peninsula be­ tween Point Spencer and Solomon. North of Cape Espenberg in the Kotzebue Sound area, however, there are few (Black, 1951). Along the Espenberg Pen­ insula coast there are both oval and parabolic dunes l to 4 m high and 3 to 7 m long pockmarked with small active blowouts. According to Black these were formed by strong onshore winds. On the ocean side of these dunes a lush elymus meadow often extends to the storm line on the forebeach (Fig. 19). There are occasional plants there of Artemisia arctica, Festuca rubra, Honckenya peploides, Lathyrus maritimus, Sedwn rosea, Senecio Pseudo-Arnica and I'oa eminens. The bottoms of some blowouts and depressions are occupied by Juncus arcticus. Farther back from the sea on these dunes, elymus dry meadows contain many forbs, crowberry patches and other dwarf shrubs and thus provide a lower but more complete plant cover (Fig. 20). Armeria r:1aritima,

Figure 19. Elymus arenari,us meadow on seaside sand dunes at Cape Espenberg. 89

Figure 20. Vegetated and stabilized sand dunes at Cape Espenberg. The dark feature in the foreground is a patch of crowberry.

leurwn triradiatwn, Carex glareosa, Ligusticwn scoticum, Myosotis alpestris, Potentilla Hookeriana and Tofieldia coccinea al so grow in the zone of elymus dune meadows. Behind the broad and more or less active seaward dunes is a series of old flat-topped beach ridges alternating with low swales containing ponds and wet meadows. These record different locations of the strand line in earlier times. They are mostly stabilized with dwarf shrub tundra vegetation, with occasional sand blowouts bearing some elymus. In this zone of older beach ridges there is often a sharp boundary between the wet meadows of the inter-ridge swales and the dwarf shrub tundra on the ridge crests (Fig. 21). 16. Saltgrass Meadow - In coastal areas at or near the mouth of streams, like the Kugruk, Inmachuk and Nugnugaluktuk Rivers, tidal action creates extensive salt flats. Around the bay south and east of Cape Espenberg there are also extensive shallow tidal mud flats. These tidal flats are often conspicuous as bright green lawn-like areas of low graminoids (Fig. 22). The salt-tolerant sedges Carex Lyngbyaei, C. Ramenskii and C. subspathacea and the grasses ?uccinellia spp. are common. Associated forbs include Cochlearia officinalis, 90

Figure 21. View along an old beach ridge and adjacent swale at Cape Espen­ berg. The swale is occupied by a wet meadow, and a darker colored dwarf shrub tundra vegetation is on the ridge. The narrow transition zone between these vegetations is clearly shown.

Potentilla Egedii~ Primula borealis and Saussurea nuda. On higher, sandy mounds there are light-colored patches of elymus. The soils of these tidal mud flats are mostly inorganic and black.

17. Bluejoint Meadow - Small meadows dominated by the grass bluejoint (CaZ.a­ magrostis canadensis) (Fig. 23) are prominent on well drained substrates on cutbanks, slopes of drainageways, in recently drained lake basins and along cliffs. In places bluejoint meadows and willow thickets form a mosaic, par­ ticularly in drained lake basins on the Espenberg Peninsula. Bluejoint meadows may also develop in response to soil disturbance, as by mining or reindeer herds, and they are frequently seen near native villages. However, on the disturbed ground over ground squirrel tunnel systems, Deschampsia caespitosa is usually dominant (Fig. 12).

J_§. Tall Cottongrass Wet Meadow - Tall cottongrass (Eriophorum angustifo ) Wet meadows, or marshes, are best developed in the wet interior basins of the Kuzitrin and Burnt River Flats. The latter basin, east of Imuruk Lake, is 91

Figure 22. View across part of a tidal flat along the lower Espenberg River near Cape Espenberg. The darker, low-lying vegetation is salt­ grass meadow. The lighter vegetation on higher, sandy sites is EZymus meadow.

Figure 23. In a bluejoint meadow near North Devil Mountain Lake. Here this grass is tussock in growth form. Behind is a willow shrub thicket. Photo by H. R. Melchior. 92 about 12 km long and 2 to 3 km wide and may, according to Hopkins et al. (Footnote 2), be a large drained lake. It was called the Goose Pasture by the gold miners, and during July it is white with flowering heads of tall cotton­ grass. On wet flats bordering Lava Lake similar meadows contain a variety of associated herbs inc 1 uding Arc top hi la fulva� Cerastiu111 Beerinyianum and Eleo­ charis acicularis (Fig. 24). Such wet meadows frequently border small thaw ponds and pools in drained lake basins and occur along the margins of slow streams. 19. \

Figure 24. Tall cottongrass wet meadow on the west shore of Lava Lake. The lake scarp behind features a low-medium willow shrub thicket. 93

'..Jater sedge2 ·r1et meadows characteristically contain peat ridges and hummocks lato 5 m in areJ and up to l m high. These consist of sphagnum peat and other fibrous organic matter. The vegetation on their tops and sides resembles G't1arf shrub t undra ·r1i th _.:._r-;.;,r·a-:Jneda. ?C:,;_,_-,:JZ-0::., crowberry, dwarf birch, Labrador­ tea and lingonberry being important. On hummocks used as nesting sites by "' n ,. • '' ··- ✓ ''•✓ V ✓ '-A. - ✓✓ ✓✓ ✓ ✓✓ 1 es , .,,r?.2";:;,vC:Y! r?.e, .w"'l - - �:A..' -�·- ,,,a+-er+owl there', ,A "re also J-,,re.... ;,Aa·,., --.: A·: �· ,,, -· _, �-,,,,..-:,.,, � and _-.,,,,;;:- �Jr::,,:i.<"77 :l.C:A.:::.- ✓ �r>".Al'7.

�ater sedge wet meadow is extensive in recently drained lake basins on the :spenberg coastal plain (Figs. 28 and 29, map units 4, 5 and 6). Frequently there are mosaics of water sedge, tall cottongrass and bluejoint �eadows. There is much variation in the density and robustness of water sedge plants on their various substrates. 20.a �auatic �eadows - On pond margins the wet meadows described above may grade into aquatic meadows with emergent herbaceous species rooted below thea water. Usually one species is dominant, but the composition is extremely variable and unpredictable from one shallow pond to the next. The grassa ...\.r::J::..:;;;hi:a _-,:.:::ia is frequently important, and other graminoids and forbs sucha ,,. as �:.;:-t-iae"7i.AJ"';l ..�:�:;�:;:::e, .=f··,::ppu.r'.A.S :;uZgc.ris and ?=:;en::i:Za ?c:us� �a may alsoa form dense stands. On some muddy lake or pond margins on the Espenberg ?en­ insula there are stands of Senecio conqes r�s which appear bright yellow ina summer lFig. 25). In deeper water submerged aquatic plants with floating leaves are sometimes important and include Caltha palu.stris, ?a.r.u.nc-.A.::...s .?�::­ �sii and 5pa:t1?ar.ium hyperborewn. Still deeper water may contain submerged aquatics such as Callitriche verna, M'JriophyUwn s-oica�wn and ::triC"�:Q._VI�;.::;::a :JA:qar�a.a ?ART III. VEGETATION MAPPING Vegetation maps can be a most comprehensive and comprehensible presentation of results of geobotanical research. They can be useful as (a) inventories of plant communities and the landscape units and ecosystems the communities represent, (b) reservoirs of basic information with which future environmental changes may be ascertained and evaluated, (c) primary tools for land-use planning and management� and (d) guides to future and more thorough research. The present mapping efforts were undertaken with these points in mind and, in addition, to test the feasibility of using Landsat imagery as the basis for vegetation mapping in the Chukchi-Imuruk area. Purposes, methods, pro­ blems and results in the use of Landsat imagery for vegetation mapping in Alaska have been treated in more detail elsewhere (Anderson, 1976). Parts of the study area were mapped at the intermediate scale of 1 :250,000 (Figs. 26 and 28) and the large scale of 1:63,360 (Fig. 29). The map unit classes were established to be as compatible as possible with the vegetation classification and descriptions presented in Part II. However, each map is individualistic. The first was made early in the study by the second author �.:\nderson �:: :::., 1974). At this time he had not been in the field and had only the recent field observations from several locations of the first author, plus a few old aerial photos to use for identifying spectral units. The second map was made later by the first author after a trip in 1974 to t e �ucn s�aller map-area in addition to the 1973 field work, and with the use a 94

½1;,·<; " ' ;5❖;;_·(·.'._,

Figure 25. An aquatic meadow on the muddy margin of a lake on the Espenberg Coastal Plain. This particular meadow features Senecio congestus, shown here, in late September, in seed. highly informative recent aerial photography. Greater familiarity with the map-area and opportunities with a large scale led to a map considerably more detailed than the first, with a classification more sophisticated than that of Part II. The Espenberg Peninsula was chosen for mapping because of the early availa­ bility of a good Landsat (then ERTS) image in color photographic format. Later, petroleum exploration interests focussed attention on Cape Espenberg. More recently good imagery has become available for the entire Chukchi-Imuruk area. However, further mapping was not possible within the scope of this study. Background The earliest known vegetation map of the Espenberg Peninsula is a sketch by Collier (1908) covering the whole Seward Peninsula at a scale of approximately 1:4,800,000. This map shows three very broad vegetation types and the western limit of spruce timber. Most of the Espenberg Peninsula is mapped as "Tundras; Willows and Grass Along Watercourses." The southeastern one third of the CHUKCHI - I IMURUK 168°W

Norton 64°N I Sound 01 100 Q I km 71

~igure 26. Locations of the larger, l :250,000-scale, map-area (Fig. 28) ar.d the smaller, l :63,360-scale map-area (Fig. 29). The map of figure 27 covers the western Seward Peninsula south and southwest of the hatched area. present map-area (Fig. 28) is mapped as ''Timberless Uplands; ~illows and Grass :..long '..Jatercourses." Collier's third map unit, "Timbered Areas, with Scatter­ 1 ing Growth of Spruce ', is 1imi ted to the eastern and southeastern parts of the Chukchi-Imuruk area, some distance from the present map-area. Sigafoos (1958a) made al :500,000-scale vegetation map of the Seward Pen1nsu:a. On the Espenberg Peninsula this map is similar to Collier's in showing a nearly 1 1 .,n:Jroken '"..Jet Tundra", with 'Wet Tundra Willows ' in the southeast. In addi­ 1 1 "':ion, it shews several units of 'Dry Tundra ' in the beach ridge zone of the northern and northwestern coast, around Devil Mountain, and around Serpentine 1 ,..;at Springs. Also shown are several units of "Coastal Marsh' , notably adja­ cent to the eastern end of Shishmaref Inlet. Two other Sigafoos map unit 1 cl asses, 'Shrub Tundra" and "Open Spruce Forest ', are not represented in the cspenberg Peninsula map-area but are shown by him in the eastern and south­ eastern parts of the Chukchi-Imuruk area. Sigafoos's ~ap is based on sub­ stantial :iotanical field work and seems to represent 1,.,iell the distribution of ~ajar vegetations, a conclusion based on comparisons with later ~aps and :he new one □ resented here. However, the level of information on Sigafcos's ~a □ is coarse, and the map suffers from the spatial and topographic inaccuracies of the 1913 base map that he used. 96 Another map by Sigafoos (1958b), at a scale of l :2,500,000, depicts vegetation types only roughly comparable classificatorially and spatially with those of his : :500,000 map. �ost of the Espenberg Peninsula is shown covered by ''-er:;aceoi..;s Tundra." foe northern and northwestern coastal strip is mapped ..nc:er the unit class "Rock Desert, Sand Plains, and Bare Rock", as are the highlands around Serpentine Hot Springs. "Shrub Tundra" is shown around Jevil Mountain, along the lower Serpentine River and in the vicinity of Ser­ �entine riot Springs. Spetz�an (1963) authored a 1 :2,500,000-scale Alaska vegetation �ao showing t�e jeneral distribution of nine major vegetation1 types, four of whicn are , shewn on the Espenberg Peninsula:1 "High Brush' of limited occurrence in thea s,Jutheast, "�oist Tundra", '..Jet Tundra and Coastal '.�arsh'', and "Barren and ,= Sparse Jry :undra." These appear to be roughly the equivalents of three J Sigafoos's (:958a) units, ">Jet Tundra '..Jillows", ''Dry1 Tundra'', "'..Jet Tundra', and, again, "Dry Tundra", respectively. Spetzmanas map is about as detailed as Si,jafoos's '.'l'ith respect to spatial information despite its smaller scale. There are a few discrepancies between the two maps causing uncertainty as to which is the more valid. Spetzman also mapped vegetation on United States Geological Survey topographic �aos in the 1:250,000 series using the same nine map unit classes as on his Alaska state map. The higher value of these maps lies in their providing 7ore jetailed spatial information for the nine broad classes. Still, the detail is coarse compared to what could be shown at this scale. These maps are Jn­ published except for transparent plastic overlays made from them, to be Jsed in conj�nction with Geological Survey maps, available through the Joint Fecerai-State Land Use Planning Corranission for Alaska in Anchorage.

KLlc�ler's (1967) map of potential natural1 vegetation1 1 of Alaska at 1:7,500,800 ::epic:s "Cottons edge Tundra (�riapr.oP'.Am) 1 and 1 /Jatersedge Tundra (.7G:2",:;.::::-)" ona :ne �s�enberg Peninsula. The former occurs in a large unit around the Devil �ountain and Killeak Lakes. The latter is continuous throughout the rest of the area. 11 riutchison's (1967) Alaska forest map shows "Non-Forest on the Espenberg Pen­ insu;a and throughout most of the Chukchi-Imuruk area.

Jiereck (in Viereck and Little, 1972)1 published an Alaska vegetation map which is �ostly a condensation1 of Spetzmanas (1963) map with some revisions based on its authoras abundant and more recent knowledge of Alaska vegetation. �owever, at one half the1 scale, 1 :5,000,000 it is necessarily less detailed soatiaily than Spetzmanas map. It is curious that the northern and north­ western coastal strip of the Espenberg Peninsula, mapped appropriately enougn as '' 3a rren11 and Sparse Dry Tundra" by Spetzman, is mapped by Viereck as "A: o i r.e 7'Jnara.

�ne Joint Federal-State Land Use Planning Commission1 for Alaska published a � :2,500,000 map which is mostly a copy of Spetzmanas (1963) practically1 Jn­ available map. It incorporates the several revisions of Vierecka11 s1 map and .:-eat'..Jres an ecosystem-oriented termino 1 ogy. "Mais t Tundra and " ,.Jet Tundra 'a ecosys:ems are shown in the Espenberg Peninsula map-area. The alpine tJndra :er� JSed on Viereck's map was retained. 97 Anderson and Belon lin Anderson, 1976; see also Maugh, 1973) presented in early 1973 a lardsat image-based vegetation map of the western Seward Pen­ insula at 1 :1 ,000,000, the first of its kind for Alaska. This map overlaos :�e Es□enberg Peninsula map area and is presented here with the map unit ::ass ter�inology slightly refined (Fig. 27). The chief contribution of this �ao beyond the better previous maps, i.e. those of Sigafoos (1958a) and S2e:z�an (1363), is its showing more spatial infor�ation for previously de­ fined 1egetations through use of geographically �maller units and several �osaic classes. In adaition, it shows the distribution of an additiona� veqe­ tation type, possibly a grassland tundra (class 7) and two ephemeral :eatures, fire scars (class 4) and □ossibly senescent vegetaticn (class 5). Methods 7he images used for mapping are photographic prints in simulated color-infrare: :or�at at scales of 1 :250,000 and 1:63,360. These were made from Landsa: sce�e 1009-22092, taken by the satellite at an altitude of approximately 500 nau:ic3'. �iles an August 1, 1972, at about 1110 hours LST. T�e product acquired fr:m the �ational Aeronautics and Space Administration was a 9½-inch simula�ed ::�:,­ infrared transparency. This was printed by projection in an enlarger onto �astman Kodak direct reversal color print paper. The desired scale was achieved by first putting the base map on the enlarger easel and adjusting the pro­ �ected image to it, using prominent landmarks as guides. Base maps comprisea □arts of sheets in the United States Geological Survey Alaska Topographic Series (Figs. 28 and 29).s A sheet of transparent plastic suitable for drafting was cut to fit the ima�e. 7his was first placed over the base map and several landmarks prominent an both the �ap and the image were traced onto it. These included lakes, �agcans anc :he coastline. Other features not readily visible on the image, includ��g s:ream forks and bench marks, also were traced onto the plastic to facilitate reference back to the base map when the plastic was used over the image. 7he �lastic was next positioned over the image by matching the prominent ;andmarks. Colors on the image interpreted to vegetation and other landscace features were outlined on the plastic. The plastic had occasionally to be shifted slightly as mapping proceeded, for an exact scale match over the ent�re �ap-area was not possible because of minor differential scale distortion be­ :�een the base map and the image. This shifting presented only an insignifi­ cant potential for spatial error because of the considerable number of land­ �arks, Tiostly lakes, that were traced onto the plastic from the base map. Lakes are aoundant in the map-area and are distinct on the image. :n preparing for vegetation mapping the image was carefully examined in orjer to differentiate spectral signatures, which are essentially color units, Jr Jnits of different hue, intensity and brightness, to the extent this is :ossible with presumably normal color vision. Strong reflected light 'Has Jsed. Interpretations of colors to vegetations were based on the assumption :hat the colors for most land areas resulted primarily from the spectral reflectances of vegetation. Vegetation is commonly known to cover the land sJrface everywhere in the map-area except for sand dunes, coastal mud fla:s, �nd rocky barrens in the mountains. Areas lacking vegetation, of minor ex:er:, 98

./" . '

Figure 27. Vegetation map of the western Seward Peninsula, Alaska, basec on ERTS image 1009-22095 (from Anderson, 1976). l.s Shrub Thicketss 9. Shrub Thicket-Wet T:.mdns 2.s Upland Tundras Mosaic 3. '..Jet Tundras 10. Shrub Thicket-Highland/ 4. Fire Scarss Mountain Areas Mosaic :;) . Senescent Vegetations lsl. Shrub Thicket-Upland �undra- 6. Highland and Mountain Areas withs Highland/Mountain Areas Sparse and No Vegetation '.·1osai c 7. Possible Grassland Tundra 12. Upland Tundra with Some Senes- j, Shrub Thicket-Upland Tundra Mosaic cent Vegetation ,.,.... PRU INIIIAl'r VlGllAI ION MP ~l LZ!i0.000 ,., Of !Ill l~l-llG PUI~. AlA\IA \ 1L~•...... ,..Jil-_ _.___•...r___,Lr__.Jz:i biliad on hrth ResowrcH lec.:hnoloV,I ~t•I I lte N1t1.!fC!:~u~~-!:'~:•=•~~~:!t1on klla..ter1 s ID ll&llll ~. .._...... ~~---~ ··--··----J I. Jwuoc.k ~ Jllftdra ■ tin 2. ~land Wet Tllfldra NDutc. bale up us.ea.IN •1th parh of the J. SlliNb fMck•t lendeletaen. IOtnbue. !.hhtauef and Teller ~dranglH. U. S. &eologh.11 S..ne7 .. Drained Ind Partt111, DratNd lhl• lakH s. ~'H,:C'l~5i::-••--• 1a1 flNdall. ,. \ ~':.i~~:c-··--· llat ...... 1. O.rf Slln,b 1ftro ~ a. CoutAI ___..,.., - T..,.n IIDul< ,. .,,.,,... ..i n...,,.,. 11n - \ a ID. hblartM lllllnll ... 1W flat II. Coo1tAI SUd - ll. ~~Ul -s.11. l.!9!!!!!.!!. \_:r;,;::: 13. a.tt --Tlllclot-- C:O.lu , .. ... llpM SMII• Salt lllur .. :-.:.

EltTS laage latwpretltlOll aM •PPlftll by J. N. Anlen•• l111ttta.te of Arctic lto1..,, Ulll•ortlly of Alub. h,......

\ ... ll, ,41'' .J;~. 8-...· @ ...'" .. '\'- o::~ 0,-4 "\ ..+" ., ...... , + \ {9&;: .. (i\ 2 \ 11- ~ \ :1:. ~\ 1-'. ~--~·- ;, ~.r'":. \ '. (JJ \ .... \.- • -··,,, .. ...

fi(JUt'C 28. 100

Figure 29. Vegetation map of the Cape Espenberg area, �laska (SEE I�SERT.) VEGETATION OF THE CAPE E ES P N BERG AREAI

p. "'h"' :t=; 1'!�.. i <111 h::,,.,--=-ri r.ir• 7":;"'s-, c.;:,t"', 1--; + 1 Im;ci

\ DJ'9,5 '\ /_" ...... _ ...... , I I \ __..I

The mapr1ed uni ts ."ire combined descrir:-tions of lanr!fo:nn and vegetation relatio:!"l'�hip�. i-h� ma1or units are first delimited wi+.h +.ex-tu.re� (k;yed below) and then more �etriled infomRt­ ion is vrovicied with a formula of symbo1.!I (key­ Landforms ed on the ri�ht); lettP,rs indicate landforns D l)r.:i.J.ned lakes Md L:ike ¥-arpin:-:: followed� rrwnbers for the Ve2'e�,at:ion type(E', c; A ctive �and Tlunefl 1-lhere a landfom is occupj ed by a mosaic of H Pinf!OS tvo or more types, numbers are separated by B Beach Ridg"s md Jnter-ridge Trouph.o:: co...,as with the first number indicating the F Polygonal Ground (Ice-wed�e Po'!.yeons) most prevalent type. Poly�ond gTOllnd ma:' occur f. M St.ream and StNtRJn ),farrlns with other landfoms. ::..i �a11 Hills, �id�es �d ?.ol linf? 'T'"!rrain J.' 1i'lats where Ice-l'P,dge Polyfons are Ab'3Ant. ITTTTTn PredrnrJ.nately herb-rlwarf shrub ty:...,e with sedge tussock� and erlC,!iCeOU!IJ ir volcanic. 4sh Hn1:mrls UllillJ dwarf shrubs, on slopes, hills, lake margins and hi� centered polygons -,nb�crlpts further descri binfr +.he ahov� l:mdfol"'T!s � Predominately herb type with sed�e wet m�adows; on flats, low centered -- 'recently

, . :warf Shrub 7 undra - :warf shrub tundra vegetation, including the four types cis:ussed in Part::, is of considerable areal i~oortance in the hiah­ iancs in the southeastern ~art of the map area (Fig. 28). 7here it aopea~s ~requently to intergrade with local rock deserts on ridges and summits which could net feasibly be mapped separately. :tis likely that in the tussock­ cwarf shrub tJndra area of class l, stands of all four dwarf shrub tundra :ypes, either too small to ~ap or indistinc: on the i~age, are widespread on '::he ~etter dn. i ned low e:es ts and summits. Dry as dwarf shrub t:.rndra occurs around ~orth Killeak Lake, and there are stands of Bigelow's sedge dwarf shrut tuncra around Serpentine ~ot Spr~ngs. 3. Coastal ~eadows-Jwar& S~rub Tundra ~osaic - 7his class encompasses several vegetation types occurring in stands too small to differentiate on the Landsat image. These vegetations occupy a coastal zone featuring a sequence of beach ridges a~d intervening troughs. Rock deserts and dryas and Bigelow's sedge Jwarf shr~b tundra vegetations form a succession on the crests and ~oper slopes of ~each ridges represented by younger stages near the ocean and older stages far:her away. On some sand dunes, especially those forming the front line of dunes between the water and the first beach ridge, there are :::::w:~<3 :::::~"-.::·,-....::.:::1 ·~:,2 ~eaaows. Between the beach ridges tall cottongrass, tall cottongrass-water sedge, and water sedge wet meadows occur on flats and in trougns. There are a:so ~ands here, some of which contain communities of aquatic plant species.

~ ~~:arian and Floodplain Wet ~eadcws - The vegetation in this class occurs an flood plains in the lower, seaward segments of several of the larger rivers. ~any of the smaller stream valleys probably contain a similar vegetation in their seaward stretches but, as with shrub thickets adjacent to small streams, stands are too narrow to map individually. 7here ~ay be stands of several wet meadow types here, with the most important being water sedge wet meadows. These may contain an open low willow layer on the more inland sites and scattered low willows on sites closer to the sea. ;5 such, the vegetation may be a kind of transition between shrub thicket and the wetter coastal meadow types. The several class 3 units in the vicinity o& Cape ~spenberg probably contain stands of this transition vegetation. There is a general decrease in abundance and stature of 'N'illows northwest1N'ard across the map area. 10. Estuarine ~arshes and Mud Flats - This map class includes river mouth areas characterized by open shallow water and wet mud flats where plant cover is absent, sparse or otherwise not dense enough to preclude the predominant appearance of water on the Landsat image. These areas may lie partly below high tide level (Fig. 22). This class also includes a few nonestuarine areas of otherN'ise similar physiographic position in the vicinity of Cape Espenberg. /egetation here, not yet studied, may be some kind of saline aquatic ~eadcw or -r:arsh. 105 11. Coastal Sand Dunes - This class includes areas of surficially unstable sar.d dunes upon which a plant cover is scant or lacking (Figs. 19 and 20) . :�ere are several such areas along the northwestern coast. It is likely :hat small stands of the :::::,"'7".A.S a.r>er..cr:.:,i.s and salt grass meadow vegetation types occur within these areas, and some dunes may bear only scattered in­ dividuals of elymus and a few ecologically similar species. 12. Bluejoint Meadow-Diamondleaf Willow Shrub T�ickets - A single occurrence of this two-component mosaic is depicted adjacent to �lorth Devil Mountain Lake on the northwest. It was mapped because it was visited and described in 1973 and was distinct on the Landsat image. Also, although very small relative to map scale, it is isolated and therefore easily mapped and labeled. 13. �et Meadow-Shrub Thicket-Pond Comolex - The single area in this map class is adjacent to North Devil Mountain lake on the east and, like the pre­ cedin£, was also visited. The shrub component includes alders and willows . As ·t1ith class 12, the feasibility of depicting it was an opportunity to make the map slightly more informative .

1 14. Open Shallow Salt ..Jater - Only one unit of this class is mapped, between two sand dune areas a few km southwest of Kividlo. Here the Landsat image was interpreted as showing open but very shallow water. A mud flat may appear at 1ow tide . The 1:63,360-Scale Map of Cape Espenberg The area of this map encompasses the coastal plain and the associated coastal dunes, sand spits and mud flats northeast of the Espenberg volcanic upland (Fig. 29). This �ao was made after the preceding one and it was possible to field-check in 1974 some of the classes established earlier. Classes 2, 3, 4, 5, 6, 8 and 10 on the earlier map were recognized also in the Cape Espenberg map area. For the most part the earlier mapping in this area was found to be valid with­ in the scope of its broad classes and the limitations of a comparatively small scale. On the present map, vegetations and their associated landforms are mapped together. landform-vegetation units are distinguished by different graphic patterns and according to a letter-number code system. Thus, an overall visual display representing the geobotanical diversity in the landscape is provided, and the viewer is directed readily to more detailed information about the map units. Some map units include a mosaic of two or more vege­ tations or landforms, and a multiple letter-number code is used for these. At the present scale, four times that of the earlier map, it was possible to portray individual pieces of the earlier mosaic classes 2 and 8 (Fig. 28) . The present map and associated field work in 1974 deal more adequately with the drained lakes and their vegetations. Earlier map class 4 (drained and partially drained thaw lakes) corresponds on the present map to D0P9,5. These arc-shaped features are depicted in Figure 29 with dashed lines. At the periphery they contain low-centered polygons with water sedge wet meadcw 106 vegetation. Toward the middle there are high-centered polygons with both tussock-dwarf shrub tundra and, still nearer the middle, wet meadow veae­ tations. These features appear to be remnants of very old drained lake basins with permafrost and well developed polygons. Earlier map classes 5 and 6 (Fig. 28) correspond to the present units labeled Dr6,10. These are thaw lake basins drai�ed rec2n�ly, within the �ast 2J years, now occupied by scattered small ponds and lush wet meadows or marsnes dominated by ·...iater sedges, tall cottongrasses, ?02 species and bluejoint. Another kind of drained lake feature appears to be of intermediate age. These, designated Jrl0,1 (Fig. 29), lack advanced polygon development and contain a mosaic of low-medium willow shrub thickets and bluejoint meadows. They were not recognized in the earlier mapping effort, although they may be similar to the earlier unit 12 (Fig. 23). The present map is also the topic of a separate paper (Racine, 1977). LITERATURE CITED Anderson, J. H. 1976. On vegetation mapping in Alaska using Landsat imagery. Special publication, Institute of Arctic Biology, University of Alaska, Fairbanks. 134 pp. 3t maps. Anderson, J. H., C. H. Racine and H. R. Melchior. 1974. Preliminary vegeta­ tion map of the Espenberg Peninsula, Alaska, based on an Ea(th Resources Technology Satellite image. No. E74-10544, National Technical :nformation Service, Springfield. 21 pp. �rgus, G. W. 1973. The genus Salix in Alaska and the Yukon. National �useu�s of Canada Publications in Botany No. 2. 279 pp. Bailey, L. H. 1949. Manual of cultivated plants. The MacMillan Company, New York. 1,116 pp. Black, R. F. 1951. Eolian deposits of Alaska. Arctic 4:89-111. Bliss, L. C. and J. E. Cantlon. 1957. Succession on river alluvium in north­ ern Alaska. Amer. Xid.. ,Vat. 58:452-469. Bliss, L. C., G. M. Courtin, D. L. Pattie, R.eR. Riewe, D. �J. A. Whitfield and P. Widden. 1973. Arctic tundra ecosystems. ;nn. ?ev. E�a:. E22�. 4:359-399. Britton, M. E. 1967. Vegetation of the arctic tundra. Pp. 67-130, �� Arctic Biology (H. P. Hansen, ed.) Oregon State University Press, Corvallis. 318 pp. Colinvaux, P. A. 1964. The environment of the Bering Land Bridge. :-!or.ogr. 34:297-329. Colinvaux, P. �- 1967. Quaternary vegetational history of arctic Alaska. Pp. 207-231, ::n The Bering land Bridge (D. M. Hopkins, ed.) Stanford University Press, Stanford. 495 pp. Collier,e;:... J. 1908. Geography and geology. Pp. 40-108, :'.r: 1he Gold Placers of Parts of Seward Peninsula, Alaska, including the :lame, Councii, Kougarok, Port Clarence, and Goodhope Precincts (A. J. Collier, F. L. Hess, P. S. Smith and A. H. Brooks, eds.). United States Geoloaical Survey Bulletin 323. 343 pp.

;uthrie, R. D. and J. V. �atthews, Jr. 1971. The Cape Deceit fauna. - , Pleistocene mammalian assemblage from the Alaskan arctic. ��,-.::;;. _-:.;,s. : : 474-570.e Ha 1 e, M. E . , J r . an d 'ti. L. Cu 1 be rs on . 1 9 70 . A four th ch e ck 1 i st of t h e lichens of the continental United States and Canada. :�e 3r�o:�J�a� 73:499-S-+3. Hanson, H. C. 1951. Characteristics of some grassland, marsh, and other plant communities in western Alaska. �co:. :,Jonogr. 21:317-378. Hanson, H. C. 1953. Vegetation types in northwestern Alaska and comparisons with communities in other arctic regions. �colog·J 34:111-140. Holowaychuk, N., J. H. Petro, H. R. Finney, R. S. Farnham and P. L. Gersper. 1966. Soils of Ogotoruk Creek Watershed. Pp. 221-273, in Environment of the Cape Thompson Region, Alaska (N. J. Wilimovsky and J. N. Wolfe, eds.) PNE-481, Clearinghouse for Federal Scientific and Technical Infor­ mation, Springfield. 1,250 pp.

�cpkins,1 0. M. 1949. Thaw lakes and thaw sinks in the Imuruk Lake area, Set1ard Peninsula, Alaska. ,I. :JeoL 57:119-131. Hopkins, D. M. 1963. Geology of the Imuruk Lake area, Seward Peninsula, Alaska. United States Geological Survey Bulletin 1141-C. 101 pp. Hopkins, D. M. 1967. The Cenozoic history of Beringia - a synthesis. Pp. 451-484, in The Bering Land Bridge (D. M. Hopkins, ed.) Stanford Univer­ sity Press, Stanford. 495 pp.e Hopkins, D. M. 1972. The paleogeography and climatic history of Seringia during late Cenozoic time. In�er-Jori 12:121-150. ropkins, D. M. and W. S. Benninghoff. 1953. Evidence of a very warm Pleis­ tocene interglacial interval on Seward Peninsula. 3:-1.:Z. Jeol. 5cc. _..;_-;-:er. 64: 1435-1436. Hopkins, D. M., J. V. Matthews, Jr., J. A. Wolfe and M. L. Silberman. 1971. A Pliocene flora and insect fauna from the Bering Strait region. ?1laeogeogr., ?1:aeoc:��-, ?1Zaeoecol. 9:211-231 . Hopkins, 0. M. and R. S. Sigafoos. 1951. Frost action and vegetation pat�er�s on Seward Peninsula, Alaska . '_,'.S. Jeol. 5:A.r. 3:..l:. 974-C:51-101. 108 Hulten, c. 1937. Outline of the history of arctic and boreal biota during the �uaternary Period. Bokforlags Aktiebolaget Thule, Stockholm. le68 pp.e Hulten, E. 1963. The distributional conditions of the flora of Beringia. Pp. 7-22, i� Pacific Sasin 3iogeography (J. L. Gressitt, ed.) Bishop Museum Press, Honolulu. �ulten, E. 1968. Flora of Alaska and neighboring territories. Stanford University Press, Stanford. 1,008 pp. Hulten, E. 1973. Supplement to Flora of Alaska and 'leighboring Territories. 3c :;.:;::,:-�s.�::iser> .'/c 126:45 9-512. Hutchison, 0. K. 1967. Alaska's forest resource. .-:.�s. P:l�J-19. 74 pp. Jonnson, A. W., L. A. Viereck, R. E. Johnson and H. Melchior. 1966. Vegeta­ tion and flora. Pp. 277-354, in Environment of the Cape Thompson Region, Alaska (N. J. \./ilimovsky and J. N. Wolfe, eds.) PNE-481, Clearinghouse for Feder a1 Sc ie nt i f i c a nd Te ch n ic a1 I n fo rma t ion , S p ri n gf ie 1 d . 1 ,2 5 0 p p . Kuchler, A. W. 1967. Potential natural vegetation of Alaska. :.:,: National Atlas, Sheet 89, U.S. Geological Survey. Mattnews, J. V., Jr. 1974. Quaternary environments at Cape Deceit (Seward Peninsula, Alaska): evolution of a tundra ecosystem. Jee:. Soc.. .::�":e:r. 3A::. 85:1353-1384. �augh, T. H. 1973. ERTS (II): a new way of viewing the earth. 3cie:,:ce 180:171-173. McCulloch, D. S. and D. M. Hopkins. 1966. Evidence for a warm interval 10,000 to 8,300 years ago in northwestern Alaska. 'Jee:. 3cc. Ar,er. 3¼ : : . 77 : 1 089- 1108 . McIntosh, R. P. 1972. Forests of the Catskill Mountains, New York. .'.for..ogr. 42: 143-161. Miller, M. M. 1964. Morphogenetic classification of Pleistocene glaciations in the Alaska-Canada Boundary Range. ?rec. .J.mer. ?hi:c. Sec. 108: 247-256.e �offit, F. H. 1905. The Fairhaven gold placers, Seward Peninsula, Alaska. �.S. GeoZ. Sur. BuZZ. 247:1-85. Palmer, L. J. and C. H. Rouse. 1945. Study of the Alaska tundra with refer­ ence to its reactions to reindeer and other grazing. :··.s. :�sh �·i:d.. Ser. ?es. ?e?t. 10:1-48. Pegau, R. E. 1968. Growth rates of important reindeer forage lichens on the Seward Peninsula, Alaska. .J.rctic 21 :255-259. 109 Polunin, N. 1955. Aspects of arctic botany. -D:307-322 .e Jorsild, A. E. 1938. Flora of Little Diomede Island in Bering Strait . 7ransactions of the Royal Society of Canada, Series 3, Section 5, Volume 32:21-38. Porsild, A. E. 1939. Contributions to the flora of Alaska. _-::;,.cd.�r>c:. 41 :141- 183, 199-254, 262-301. Racine, C. H. 1976. Part II, Flora and Vegetation. Pp. 39-139, :.'.,: Final �eport, Biological Survey of the Proposed �obuk Valley Natio�al Monu­ �ent (�. R. Melchior, ed.) Alaska Cooperative Park Studies Unit, Sialagy and Resource Management Program, University of Alaska, Fairbanks. Racine, C. H. 1977. Tundra disturbance resulting from a 1974 drilling opera­ tion in the Cape Espenberg area, Seward Peninsula, Alaska. Institute fJr Northern Studies, Wolcott, Vermont. 47 pp. Sigafoos, R. S. 1951 . Soil instability in tundra vegetation. 51 :281-298. Sigafoos, R. S. 1958a. Plate 8, Vegetation Map, Engineer Intelligence Study 185, Seward Peninsula, Alaska. Military Geology Branch, United States Geological Survey. Sigafoos, R. S. 1958b. Vegetation of northwestern North America, as an aid in interpretation of geologic data. :·.s. 'JeoZ. Sur. 5:.::. 1061-E: 165-185.e Soetz�an, L. A. 1963. Terrain study of Alaska, Part V: Vegetation. Military Geology Branch, United States Geological Survey. Swan, J. M. A., R. L. Dix and C. F. Wehrhahn. 1969. An ordination technique based on the best possible stand-defined axes and its application to vegetational analysis. ?aology 50:206-212. Tedrow, J. C. F., J. V. Drew, 0. r:. Hill and L. A. Douglas. 1958. Major genetic soils of the arctic slope of Alaska. �- Soi: Sci. 9:33-45. Viereck, L.eA. and E. L. Little, Jr. 1972. Alaska trees and shrubs. United States Forest Service Agriculture Handbook 410. 265 pp. Young, S. B. 1971. The vascular flora of St. Lawrence Island with special reference to floristic zonation in the arctic regions. Contributions from the Gray Herbarium of Harvard University 201 :11-115. Young, S. B., ed. 1974. The environment of the Noatak River basin, Alaska. Center for Northern Studies, Contribution 1, Wolcott, Vermont. 584 pp. Yurtsev, B. A. 1972. Phytogeography of northeastern Asia and the problem of transberingian floristic interrelations. Pp. 19-54, in Floristics and Paleofloristics of Asia and Eastern North America (A. Graham, ed.) Elsevier, Amsterdam. 278 pp. 110 APPENDIX I Location, physiography and dominant species of vegetation stands sampled in the Chukchi-Imuruk area in 1973. Soil type codes are from Holowaychuk and Smeck for the stands they sampled. Physio­ Stand Number graphic Elev'n Slop,ee Soil Oomi nant and Location Posit' n m ,, Aspect Type Taxa

1.e N. Killeake slope 40 8 SE Lakee 2.e N. Ki 11 eake crest 82 0 Lakee 3.e Lava Lakee slope 118 8 NW 3etu.:c. nana Ledu.rn ;a:�a ";r1e

crest 122 2 A Er�cr;hcr>:<17? ::"'!­ Ja.:: ... 4.e Lava Lakee atz.t117'l

5.e Imuruk Lakee slope 345 4 SW A

6.e Imuruk Lakee slope 435 14 SW �iaea

7.e Imuruk Lakee crest 460 7 SW C

8 NE D lichens 8.e Imuruk Lakee slope 440 'lacciniu.m :,Z.i;in­ osu"Tl

9.e Inmachuke slope 260 13 E D Rivere 10.e Inmachuke slope 206 11 E A �-;;,..cqnUJ': spp. Rivere 1/aa�ini�'7'! "':ti-,:.; ,n.­ csur.z 11.e Inmachuke slope 166 6 E A Rivere at:wn

12.e Inmachuke slope 106 3 E A Care= 3ige1otv�:::. Rivere EricphoP",A,� :;.1g:-n- 111

APPENDIX I CONTINUED Physic- Stand rlumber graphic Elev'n Slooe:t Soil Dominant and Location Posit' n m .0 Aspect Type Taxa - .. 13. Serpentinee slope 153 3 w A .:;r � V::; r.:;;.A.� !"' ·:.:::.Jir.- _:;:::;;g'/ Hot Springs ... • ■ �aaa-:-;,::..A-":--: :i .... :.;:...-:-

_,,...... , O.A.i • ......

14. 168 5 w �"?!1vC.JY::.i.�- . Serpentinee slope A ...... spp. Hot Springse /-�:!a-:.�-:..:�� :t V -:. I:::- � 3A.."?Z

15. Serpentinee slope 183 8 w A 2riov°r'.o!".ll'n :J��::>3- se ar:;u'71 Hot Spring I:,edwn �a!�s:;re

16. Serpentine slope 213 10 w A-De Ca.re:: 3iga !o'.J"':,:, Hot Springse �'a�ain-:,�� :.tZ:,g--:,n- oswn 1 17. 244 13 w ·"::::.re= Bige Zct- � i Serpentinee slope A-De .,., . . Hot Springse ,aoa-z.n-z.:.an :.t�-:.:2:.�- OSU."1

18. Serpentine slope 305 18 w D Lee.um pabs;'!'e Hot Springse ;"aaaini�":"l u::gi�- oswn 19. Devil Moun- slope 31 8 E A-De 3etuia nana tain Lakese Care::: BigeZc�i:. 20. Devil Moun- slope 46 5 E A 2riopho'l"'.AJn ?)ag::n- atum tain Lakese .-=ru.bus ahamc.er:o!"-'s

21. 4 E A Eriophor"r.: :,:=:::--::n- Devil Moun- slope 61 :itwn tain Lakese .=iu.bus ar'.amaer;oY"'.A.S

22. Devil Moun- crest 68 3 E A �azae= aqu==:, : ... �s tain Lakese lichens :arex aqua:;:.v. � ... . .,a 23. Cape Espen- swale 6 0 berge ';are= ar.ordor- 24.e Cape Es pen- swale 7 0 berge rhiza ,,- e �r:,;.r"I ni.:.::n:.i": ":,. Cape Espen- swale 8 0 z� berge mosses 112 APPENDIX I CONTINUED

Physio- 1 Stand Number graphic Eleve n Slo12e Soil Dominant and Location Posit'n m �o Aspect Type Taxa

26.e Cape Espen- s•,-4ale 6 0 --:�rex :: n.c c>i.cY' - berge rrit.z� water ...... 27.e Serpentinee brew 355 18 w F , �ac-:,11:..:t.� :i.:�:;:,r:- QS�'T! Hot Springse ••,,,• _,, ...... :'2.c::in:.i/4� i.,✓ .,n:; - :ic:.ec:.

28.e Serpentine crest 390 13 w F 1 i chens Hot Springse bare ground 29.e Serpentine slope 300 25 NE .:._r�tos�i2-;;i:y- . Z.Qs Hot Springse 2L..t::'1...i"..a 1 i ch ens 11 E :c:.re= 3.-.:;e!c?.;.;i ..� 30.e Cevil Moun- crest 30 D - . "' . :�a.aainiZA.r.? :A. :.,"':_. .:,7 ...r: - tain Lakese oswn

,. 31.e Imuruk Lakee brow 435 14 SW .. =?.r'c.,cc.� � -;r,:_,:;r. sp. bare ground 32.e Lava Lakee lava 107 0 E �etr1.Dn ;,z,f,.,;:�e-rn flow 1 ichens 0 E 33.e Lava Lake lava 105 :.edwn paZ.ust!'e.. _.,.,,,: _,,, ., lac::Jini-u,-n i.,,, ., ....�- flow Iiaea

�.,,...... ,.,, ·� 34.e Lava Lake lava 102 0 "::r:rpetr:un . .. ""';; ... ;,'(,,, . flow lichens 110 lc:.ccini-;,;,,� ;-r-:: ::ia- 35.e Lava Lake lava 6 N flow !iaea 1 i ch ens 8 E F :r�,as 36.e uevil Moun- slope 32 sp. tain Lakese bare ground :r2as 37.e N. Killeake beach 26 sp. Lakee bare ground Cazae= Bi e Za���:, 38.e N. Ki 11 eake beach 28 g Lakee bare ground 113

? APPENDIX ! CONTINUED

Physic- 1 Stand Number graphic1 Elev n Sloee01 Soil Dominant and Location Posit n m ,0 Aspect Type Taxa

�i E�e°t!""A.� 'V' "' .... ,..,., - 39. . Kil 1 eak beach 27 . .,..,..::: .. ,A.,. Lake bare ground 40. Devi 1 ��oun- beach 32 Jr�c:s sp. tain Lakes bare ground 41. Devil Moun- beach 33 lichens tain Lakes bare ground 42 Cape Espen- beach 10 :,,r��ost�;hy :ca berg -=.Z;ir.a bare ground 43. Kuzitri n beach 442 �'7rr:etr� ..�"Z..J?"'..Qn Lake bare ground 44. Kuzi tri n beach 445 G ':a.re::: =�g a Z.;,,_,i,:. Lake lichens