\ " & e•earch Center • SH-ell Computer Complel!t 1010 Gau•e 1.A 7(1458
Cover:
Illustration of Sphagnum magellanicum by Mary Jane Spring. The photo illustrates a pond border bog in Vermont with a well-developed fl oat i ng mat. Biological Report 85(7.16) July 1987
THE ECOLOGY OF PEAT BOGS OF THE GLACIATED NORTHEASTERN UNITED STATES: A COMMUNITY PROFILE
by
Antoni W.H. Daman Department of Ecology and Evolutionary Biology The University of Connecticut Storrs, CT 06268 and Thomas W. French Division of Fisheries and Wildlife Commonwealth of Massachusetts Boston, MA 02202
Project Officer Walter G. Duffy U.S. Fish and Wildlife Service National Wetlands Research Center 1010 Gause Boulevard Slide 11 , LA 70458
Performed for U.S. Department of the Interior Fish and Wildlife Service Research and Development National Wetlands Research Center Washington, DC 20240 l.ihnirv of Co•1gress Cataloging-in-Publication Data Damman, Antoni W. H. The ecology of peat bogs of the glaciated northeastern United States.
(Biological report 85 (7.16)) "July 1987. II Bibliography: p. Supt. of Docs. no.: I 49.89/2:85(7.16) l. Peat bog ecology--Northeastern States. I. French, Thomas W. II. Duffy, Walter G. Ill. National Wetlands Research Center (U.S.) IV. Series: Biological report (Washington, D.C.) 85-7. 16. QH104.5.N58D36 1987 574.5'26325 87-600237
This report may be cited as follows:
Damman, A.W.H., and T.W. French. 1987. The ecology of peat bogs of the glaciated Northeastern United States: a community profile. U.S. Fish Wildl. Serv. Biol. Rep. 85(7.16). 100 pp. PREFACE
This monograph on the ecology of peat This profile is intended to provide a bogs of the glaciated Northeastern United useful reference to the scientific States is one of a series of U.S. Fish and information available for peat bogs of the Wildlife Service profiles of important glaciated Northeastern United States. The freshwater wetland ecosystems of the profile includes a description of the United States. The purpose of this distribution of peatlands and the various profi 1e is to synthesize the literature types of peatlands. The authors also available for peat bogs of the glaciated discuss the physical, chemical, and portion of the Northeastern United States hydrologic properties of peat bogs as well and to describe the ecological structure as energy flow and nutrient fluxes and functioning of these freshwater associated with peat bogs. Several wetlands. chapters are devoted to the biotic communities of peat bogs, human The glaciated portion of the North disturbances, and recommendations for eastern United States extends from the future research. Canadian border in the north to the Pocono Mountains of Pennsylvania in the south. Peat bogs may be found scattered through Any questions or comments about or out this region where conditions favor requests for this publication should be peat development. directed to: Peat bogs depend on acidic, nutrient poor water for development and usually occur in areas underlain by sand, gravel, Information Transfer Specialist or nutrient-poor glacial till. The National Wetlands Research Center hydrologic characteristics and chemical U.S. Fish and Wildlife Service composition of bog water influence both NASA-Slidell Computer Complex nutrient cycling and plant community 1010 Gause Boulevard development within bogs. Slidell, Louisiana 70458
iii CONVERSION TABLE
~ To Obtain mi 1l imeters (mm) 0,03937 inches centimeters (cm) 0.3937 inches meters (m) 3,281 feet meters (m) 0.5468 fathoms kilometers (km) 0, 6214 statute miles ki lorneter'S (km) 0. 5396 nautical miles
... - -·" ~ " , , . I-·',.' \ '..:.q~;a.rc ~cct -'"l~.11.Ji l !!•~~...,Li J \111 / :!.C. 7S squ Ii t0rs ( I) 0. 2642 gallons cubic meters (m:',J 35. 31 cubic feet cubic: meters (m:i) 0 0008110 acre-feet 0. 00003'.:>27 ounces 0, 03527 ounces 2 20:, pounds 220b, 0 pouncls l 102 short tons kiloc:dlori (kcal) 3, %8 British thermal units Celsius degrees (°C) l. 8(°C) + 32 Fahrenheit degrees tric: inches 2'i. 4() mi 11 imeters inches 2, 54 centimeters feet (ft) 0. 3048 rne te rs fa th om', l. 829 meters statute mi It", (mi) L' 609 k i I ome ters nautical mi if!S (nmi) l. 1.1':>2 kilometers square feet (ft~) 0 0929 square meters square mile', (mi;:) 2, ':i90 square kilometers dC rt:~ 1.) Q, 404/ hectares CjiJ I I on~, ( ~jil I ) 3. 78'J Ii ter,, culli c fr'et (ft::) (J 02fJ31 cubic meters acre-fept 1233, () cubic meters ounces (01) 283S(J. () rni 11 i ljl'ams olrnc:es (cu) ?B. 3'.J qr ams pourHh ( I t1) (I 4'.Jl6 k i I 09rams pounds ( 111) (i l)(l04'i metric terns short tons (ton) 0 9072 metric tons British thermal units (Btu) (). 2520 ki loc:a lories fahn>nheit deqrees (°F) 0, 'JS56 (°F - 32) Celsius clegrees iv CONTENTS PREFACE i i i CONVERSION TABLE iv FIGURES . . . . vii TABLES . . . . ix ACKNOWLEDGMENTS x INTRODUCTION . xi 1. DEFINITION AND GENERAL DESCRIPTION l 1.1. Definition of Peat Bogs and Related Peatlands 1 1.2. Geographic and Ecologi:::a: Range of Peat Bogs Iricluded 3 1.3. Distribution in the Landscape 3 1.4. Major Physiognomic Types ... 5 1. 5. Peat Bogs as Landforms . . . . 6 1.5.1. Peat bog-lake systems 6 1.5.2. Perched water-peatland systems 8 1.5.3. Peat bog-stream systems 10 1.5.4. Ombrogenous peatland systems 11 2. FACTORS CONTROLLING PHYSICAL PROPERTIES 12 2.1. Substrate ...... 12 2.1.1. Classification based on botanical composition 12 2.1.2. Classification based on degree of decomposition 13 2.2. Physical Properties ...... 14 2.2.1. Water content and water retention 15 2.2.2. Hydraulic conductivity 16 3. HYDROLOGY AND WATER CHEMISTRY 19 3.1. Water Storage .... 19 3.2. Water Movement in Bogs 19 3.2.l. Lateral flow. 19 3.2.2. Vertical flow 21 3. 3. Water Chemistry 21 3.3.1. Chemical differences between meteoric and telluric water 21 3.3.2. Chemical composition of ombrotrophic bog water . 22 3.3.3. Chemical composition of minerotrophic bog water 24 4. STORAGE AND FLUXES OF ELEMENTS 27 4.1. Introduction ...... 27 4.2. Energy Flow ...... 27 4.3. Fluxes of Nutrients and Other Elements 28 4.3.l. Causes of differences with upland ecosystems 28 4.3.2. Inputs ...... 29 4.3.3. Temporal changes in elemental fluxes 29 4.3.4. Accumulation of elements in bogs 29 4. 3. 5. Elements removed from peat bogs 32 v 5. PEAT BOG VEGETATION . . . . . 34 5.1. Floristic Composition of the Plant Communities 34 5. 1. l. Forests . . .. 35 5.1.2. Tall-shrub thickets 39 5.1. 3. Dwarf-shrub heath 41 5.1.4. Vegetation dominated by sedges 48 5.1.5. Carpet and mud-bottom vegetation 50 5.2. Vegetation Patterns in Peat Bogs .... 51 5.2.1. Factors controlling the vegetation pattern 51 5.2.2. Vegetation patterns in relation to water flow and habilaL S3 5.3. Geographical Changes in Hydrology and Vegetation 60 6. ANIMAL COMMUNITY COMPOSITION 63 6. 1. Vertebrates 63 6. 1. l. Mammal s 63 6.1.2. Birds 65 6.1.3. Amphibians and reptiles. 68 6.2. Invertebrates 70 7. HUMAN DISTURBANCES AND THREATENED BIOTA 77 /. l. ~eat Mining ...... 77 7.2. Fires ...... 77 7. 3. Other Anthropogenic Effects 79 7.4. Rare, Threatened, and Endangered Species 79 8. RECOMMENDATIONS FOR RESEARCH 82 8. 1. Classification of Peat Bogs 82 8.2. Ecological Processes . 82 8.3. Hydrology ...... 82 8.4 Vegetation ...... 83 8.5. Bog Development and Succession 83 8.6. ~lora and Fauna 83 REFERENCES 85 APPENDIX: Glossary of Terms .. 97 vi FIGURES 1 Major types of peatlands in relation to source of water .... 2 2 Southern boundary of ombrogenous bogs in relation to the major vegetation zones of the region ...... 4 3 Major peatland zones in the northeastern United States .. 5 4 Types of peat bog-lake systems common in the region 7 5 Bog vegetation in center of former lake ...... 7 6 Moat of moat bog during period of low water in late fall. 8 7 Pond border bog with narrow strip of bog vegetation 9 8 Pond border bog with well-developed floating mat .. 9 9 Soligenous mire with pronounced pool-string pattern 10 10 Ombrogenous peatland with almost concentric pool pattern ..... 11 11 Core sample collected in the surface peat of an Empetrum-Sphagnum fuscum vegetation of a coastal plateau bog .... . 13 12 Properties of fibric, hemic, and sapric peat ...... 15 13 Relati?n betweery bulk density of peat and its water retention at various tensions ...... 16 14 Relation between fiber content of peat and its water retention at various tensions ...... 16 15 Water retention in different peats ...... 16 16 Relation between hydraulic conductivity and degree of humification of different peat types ...... 17 17 Relation between hydraulic conductivity and peat types ...... 18 18 Properties of acrotelm and catotelm of peat bogs ...... 20 19 Loose surface peat with Sphagnum magellanicum and S. angustifolium. 22 20 Sphagnum magellanicum - 23 21 Sphagnum pap il 1osum ...... 23 22 Sphagnum fall ax ...... 24 23 sphagnum rube 11 um ...... 24 24 Nitrogen concentration and C/N quotient in cores from an oligotrophic lake-fill bog, an oligotrophic floating mat, a mesotrophic red maple swamp, and an ombrotrophic bog ...... 31 25 Ericaceous dwarf-shrubs common in peat bogs of the Northeast. 43 26 Em~etrum nigrum-Spha~num fuscum community ...... 44 27 Sp agnum fuscum-Kalm1a angustifolia corrmunity on the slope of a plateau bog ...... 45 28 Sphagnum fuscum-Gaylussacia baccata community in the center of a convex ra1sed bog ...... 45 29 Sphagnum rubellum-Chamaedaphne calyculata corrmunity on quaking bog mat ...... 46 30 Margin of bog mat enriched by lake water .... . 47 31 Sphagnum fallax-Chamaedaphne calyculata corrmunity 47 32 Carex rostrata co!llTlunity on shallow minerotrophic peat. 49 33 Extremely poor fen community in soligenous fen in northern Maine. 49 vii Nu!T!ber 34 Shhagnum-Scirpus ces~itosus community in the center of a plateau bog. 50 35 Rynchospora alba mu -bottom community surrounded by dwarf-shrub vegetat1 on-.-...... 51 36 A fen window in a Sphagnum rubeLL~~-~hamaedaphn~ vegetation on a quaking bog mat ...... 52 37 Changes in water flow and nutrient input to the bog surface during hydrarch succession ...... 53 38 Vegetation pattern of peat bog-lake systems in southern and northern part of region ...... 55 39 Vegetation pattern and changes in water chemistry in moat bogs. SS 40 Vegetation pattern and water flow in limnogenous bog system associated with an ombrotrophic bog ...... 57 41 Vegetation pattern and water flow in perched-water peatlands influenced by nutrient-poor minerotrophic water .... 59 42 Vegetation pattern in the three major raised bog types of northern New England ...... 61 43 Northeastern United States breeding ranges of six boreal bird species characteristic of peat1ands ...... 66 44 Comparison of bird distribution typical of a lake-border bog in the northern and southern pa rt of the region...... 67 45 Distribution of ten bird species in Maine peat1ands ..... 68 46 Dendrogram of overlap of vegetation types based on similarities of 1983 and 1984 bird species composition on eight Maine peat1 ands ...... 68 47 Inverte0rate associates of the pitcher plant (Sarracenia purpurea). 71 48 Raised bog from which peat was harvested by cutting ...... 78 49 Raised bog surface harvested by vacuum method ...... 78 viii TABLES Peat humification scale (von Post scale) based on properties that can be observed in the field ...... 14 2 The relative concentrations of the most abundant elements in the earth crust, soil, and water ...... 25 3 Comparison of ionic composition of precipitation with that of ombrotrophic bog water and minerotrophic brook water ... 25 4 Major trends in the dominant tree species in peatland forests with respect to nutrient regime and geographical location. 35 5 Floristic composition of the tall-shrub thickets and black spruce bog fores ts ...... 36 6 Floristic composition of the dwarf-shrub bog...... 38 7 Floristic composition of ombrotrophic and oligotrophic vegetation dominated by graminoids ...... 40 8 Mud-bottom and Sphagnum carpet communities ...... 41 9 Species showing clear regional differences in abundance within the region ...... 42 10 Macrolepidoptera characteristics of Northeastern peatlands. 72 11 Odonates characteristic of Northeastern peatl ands .... 75 12 The distribution of nationally or regionally rare plant species in peat bogs of t~e northeastern United States 80 13 State rare and endangered vertebrates characteristic of Northeastern peatlands ...... 81 ix ACKNOWLEDGMENTS Several inaividuais provided iniormation zation of the chapter on peat buy veyeta or help during the preparation of this tion. Walter Duffy helped throughout this publication. We particularly thank George project with advice and by arranging for Folkerts, Alan Hutchinson, Chris Leahey, the photographic work; his help with other Thomas A. Perry, Dale Schweitzer, and problems speeded the completion of tr1is Bruce Sorrie for their contributions, and report. Richard Andrews and Hank Tyler for showing us a variety of peat bogs in the field. A special debt of gratitude is owed to Jim Cardoza, Loretta C. Johnson, Gwilym Ellie DeCarli for the laborious typing of Jones, and Kenneth J. Metzler reviewed the manuscript, a painstaking and seem parts of the manuscript. ingly never-ending task; and to Mary Jane Spring tor preparing the tine plant draw Discussions with Kenneth J. Metzler ings and many of the other illustrations helped to improve the contents and organi- in this volume. x INTRODUCTION Peat bogs support vegetation strik tneir stratigraphy. However, the present ingly different from that of uplands as conditions rather than their history of well as that of other wetlands. Conifers, development control the vegetation, nu ericaceous shrubs and peat mosses (~ trient cycling, and water movement and num spp.) are major components of the veg whatever depends on them. Therefore, this etation of bogs and usually determine community profile focuses on conditions their general appearance. Their superfi and processes in existing bogs and deals cial resemblance tends to hide the differ only peripherally with development and ences among them. Therefore, it is not peat stratigraphy, and only insofar as always recognized that the conditions in they affect present processes or further peat bogs and the processes that maintain bog development. them can vary greatly. This community profile describes the Continued urbanization and recrea peat bogs of the glaciated northeastern tional deve 1 opmen ts infringe upon many United States. Information on these peat peat bogs. In recent years, there has bogs is fragmented and major gaps in our also been a renewed interest in peat as an knowledge about them exist. This applies energy source, and several peat i nvento to virtually all aspects of bogs. This ri es have been carried out (Cameron 1970, publication synthesizes our knowledge 1974, 1975; Cameron and Anderson 1980; about the vegetation, fauna, habitat con Cameron et al. undated). Research on ditions and ecological processes in these peatlands has not kept up with this. This wetlands. Because of limited published profile provides background information information on peat bogs of the Northeast that can help us predict the effect of we included much unpublished data, espe changes in the landscape and in land use, cially on the vegetation. Regarding other as well as explain changes taking place in aspects of these bogs, it was necessary to peat bogs. extrapolate from information on peatlands outside the region. Peat differs in many respects from other soils. For this rea son, its special properties and their The nomenclature in this volume fol effect on retention, movement, and chemis lows Fernald (1950) for vascular pl ants; try of the bog water are discussed. This Stotler and Crandall-Stotler (1977) for knowledge is essential for understanding liverworts; Hale and Culberson (1966) for the present vegetation pattern, but it lichens; Crumetal. (1973) formosses, also provides an insight into the differ except for Dicranum bergeri Bl and. and D. ences among bogs and the changes that can leioneuron -K~;-Ancirus (1980) for be anticipated as a result of disturbance Sphagnum, except for SthaSnum pulchricoma in a peat bog or the surrounding uplands. P. Beauv; Jones et al. 19 2) for mammals; American Orni thol ogi st' s Uni on ( 1983) for All bogs did not form in the same way. birds; and Collins et al. (1982) for Their development is clearly expressed in amphibians and reptiles. xi CHAPTER 1. DEFINITION AND GENERAL DESCRIPTION 1.1 DEFINITION OF PEAT BOGS AND In this community profile, "bogs" are RELATED PEATLANDS peatlands with a well-developed moss car pet dominated by Sphagnum. Therefore, The term "bog" in this community pro bogs include ombrotrophTC and minero file refers to nutrient-poor, acid peat trophic wetlands that are acid and nut lands with a vegetation in which peat rient-poor, and in which peat has accumu mosses (Sph?_9_11Um spp.), ericaceous shrubs, lated. This terminology is also more in and sedges-TC.Yperaceae l play a prominent keeping with the conventional use of the role. Conifers, such as black spruce word and with the definition in Webster's (Picea mariana), white pine (Pinus stro Dictionary, where a bog is described as bus!,andlarch (:...arix laricina) are often "wet spongy ground, especi a11y a poorly present. The former can--d0m1nate the veg drained usually acid area rich in plant etation of some peat bogs. residues, frequently surrounding a body of open water, and having a characteristic flora of sedges, heaths, and Sphagnum." Water is critical for the development and maintenance of all wetlands. Peat- Peatl ands are 1andforms as wel 1 as 1ands can be divided on the basis of the vegetation types. As a landform, peat source of the water into wetlands receiv lands are complexes of plant communities. ing only rain water and snow (ombrotrophic All peatlands include minerotrophic sites, bogs) and those influenced also by water at least in their margins. Therefore, the that has been in contact with the mineral disti~ction between ombrotrophic and min soil (minerotrophic peatlands). The water erotrophic peatlands is of no value in chemistry of the latter can vary greatly, dealing with peatlands as landscape units. and minerotrophic peatlands include a wide A practical subdivision of peatlands as range of wetlands. Hydrologically and landforms can be based on the nature of ecologically, the distinction between the water that controls their development. ombrotrophic and minerotrophic peatlands This was originally suggested by von Post is important, especially in dealing with and Granlund (1926) for south Swedish peat nutrient-poor peatl ands. The boundary deposits, and subsequently more clearly between these two types of peatlands, the defined by Sjors (1948). They distin mineral soil water limit (Du Rietz 1954), guished ombrogenous, topogenous, limnoge is usua·11y marked by the appearance of nous and soligenous peatlands. The major more nutrient-demanding species. In differences are shown in Figure 1. recent years, there has been a tendency among peat land researchers to fo·11 ow the Precipitation controls the development Scandinavian practice of restricting the of ombrogenous peatlands. They are terms "bog" ancl "fen" to ombrotrophic and restricted to humid, temperate climates minerotrophic peat lands, respectively. where peat can accumulate independently of This restrictive use of the term bog is ground water or seepage water. Topogenous unfortunate when dealing with vegetation, peatlands develop in topographic positions because weakly minerotrophic fens have a where water accumulates, and they are floristic composition and structure very maintained by a permanent ground-water similar to the vegetation of ombrotrophic table. These peatlands can occur under a peatlands, whereas floristically they have wide range of climatic conditions from the little in common with nutrient-rich fens tropics to the arctic. Limnogenous peat (Malmer 1985). lands develop along lakes and slow-flowing LIMN OGE NOUS SWAMP BOG SWAMP I MARSH TOPOGENOUS . ' KETTLE HOLE . . BOG l v ' DOMED OR CONVEX RAISED I BOG OMBROGENOUS i + t PLATEAU l~ BOG i i i AAPA MIRE AND SOLIGENOUS SLOPE FEN AREAS AFFECTED BY MINERAL-SOIL WATER _..,... SOURCE OF WATER ANO ~f(:< ';'::I DENSITY INOICATES RELATIVE FERTILITY OF MAJOR FLOW WATER Figure 1. Major types of peatlands in relation to source of water. Note differences in the direction of water flow. Blanket bog, another ombrogenous peatland type, is not included. 2 streams under a wide v~~iety of c1imat~c ~atEr c~~ ~-au~c co~ditions appr0achi~g conditions. Soligenous peatlands depend ombrotrophy on the bog surface of the on a reliable source of minerotrophic central part of a topogenous bog. How seepage water. They are characterized by ever, truly ombrotrophic conditions do water that seeps through or over the sur not appear to occur in these bogs. face peat and are most common in regions with a large surplus of precipitation over The vegetation of the majo~ types ?f evapotranspiration. Therefore, soligenous raised bogs in the Northeast (Figure 3) 1s peatlands become less common south of the briefly described, mostly. to emphasize zone with ombrogenous bogs, but some can how oligotrophic bogs differ and to be found even in Southern New England. provide an understanding of the geo graphical chanqt=5 within this region. The hydrology of oinbrogenous bogs differs fun 1.2 GEOGRAPHIC AND ECOLOGICAL RANGE damentally from that of topogenous and OF PEAT BOGS INCLUDED limnogenous bogs (Figure 1). It is dis cussed only peripherally here; more The southern limit of ombrogenous oogs detailed information can be found in Iva in eastern North America is located within nov (1975), Ingram (1982, 1983), Darrman the Northern Hardwood Forest Zone (Figure ( 1986a). 2). This boundary does not correspond with any clear vegetation boundary on upland sites, because the length and 1.3 DISTRIBUTION IN THE LANDSCAPE warmth of the vegetative season are the primary climatic controls on the zonatfon Peat bogs depend on acidic, nutrient in the forest vegetation, whereas the type poor water. In northern and northeastern of bog development is determined primarily Maine they can be found in various land by the humidity of the climate (Eurola and scapes, but south of the I imi t of om Ruuhfjarvi 1961; Darrman 1979a). Raised brogenous bogs they are restricted bogs, including plateau and convex domed primarily to two types of landscapes: bogs, occur north of the ombrogenous bog limit (Darrman 1977, 1978b; Dat1111an and Dow (1) Areas underlain by sands and gravels, han 1981; Worley 1981), and soligenous occurring mainly in valleys and on bogs become common in the hilly, north coastal plains. These deposits are western part of Maine (Sorensen 1986). mostly of glaciofluvial origin, but locally they include marine and aeolfan Geographically, this community profile materials. Bogs occupy some of the includes New England, northeastern Penn depressions and kettle holes of this sylvania, and the adjacent parts of New landscape. Their development is con York. The Adirondacks are not included, trolled by a water table maintained although much of this information will within these deposits. also apply to bogs in that area. Ecologi cally, this profile deals mostly with oli (2) Areas underlain by glacial tills gotrophic Sphagnum-dominated bogs. Bog- derived from acidic rocks such as 1ike vegetation on mineral soil or on peat gneiss, schist, sandstone, and granite. less than 30 cm deep is not included, and Here, bogs develop in depressions with neither are the soligenous fens north of a water table perched on compact till the southern limit of ombrogenous bogs or bedrock. Conditions favorable for (Figure 2). their development can occur at any ele vation, including h111 tops wfth This community profile focuses pri- depress1onal sites. In ti11 land marily on the topogenous and 1 imnogenous scapes, peat bogs are rare or absent in peat bogs that occur throughout the glaci the larger valleys because the water is ated northeastern United States. The veg usually enriched by nutrients leached etation of these bogs is influenced by from the uplands. minerotrophic water, although this water is nutrient-poor. The degree of minero Peat bogs develop also along lake trophy varies spatially within a bog as shores and slow-flowing streams ff the well as seasonally. Dilution with rain water is nutrient poor. 3 \ \ \ .. SOUTHERN LIMIT OMBROGENOUS BOGS • .. --·· .-- l \. \ t~~'40\e4 APPALACHIAN OAK I I NORTHERN HARDWOOD BOREAL AND COASTAL - SPRUCE-FIR Figure 2. Southern boundary of ombrogenous bogs in relation to the major forest vegetation zones of the region. 4 Inland d Bay of Fundy Domed Bogw{~ Plateau Bogs I w Topogenous Peotlands \ · " ,...-. .. -<+!+ + .. .,,--:; ...... + / ...... \... + • + + + + + +• + ...... + + ... + + \+ + + ...... , ...... ~ ... / + + + + + + + ,+ + + + + + + + ' + + + + + + + + + + + + + + + + ·). + + + + + + + + + + + + + + +\+ + + + + + t + ...... · ... ·.· ... · ... · ... ~· ... ·+··· + \+ ·.· ... ·.·.·\.· +++++"\ .. ... \ Figure 3. Major peatland zones in the northeastern United States. 1.4 MAJOR PHYSIOGNOMIC TYPES Dwarf-shrub bogs. Dwarf-shrub bogs often contain scattered larch ( Larix l arici na) The bogs in this community profi1e or black spruce (Picea marianaY-:---ine include five major physiognomic vegetation dwarf-shrub layer rs--dominated by ever types. Three of these make up most of the green eri caceous shrubs. According to the bog vegetation: U.S. Fish and Wildlife Service (FWS) wet- 5 land classification (Cowardin et al. 1979) Palustrine, per·s1stcnt emergent wetlands. these bogs are classified as Palustrine, The bog lawns cover extensive areas only hroad-leaved evergreen, scrub-shrub wet in the bogs of northern coastal Maine and lands, saturated with fresh-acid water. in Canadian bogs. Moss carpets, including In most of the region, leather leaf (Cha mud-bottoms, occur in most bogs but mostly maedaphne calyculata) is conm1only the dom as small, isolated patches. inan~warf-shrt~and the soils are usu ally medifibrists or hemists of variable depth. Dwarf-shrub bogs occur mostly in glacial kettle holes, as quaking bogs 1.5 PEAT BOGS AS LANDFORMS ~10!"!g the mar']iriS 0f nli90trophic oonds. and along slow-flowi~g. oligotrophic The bog landforms recognized here show brooks. In the northern part of the basic differences in their development, region and at higher elevations, sheep vegetation zonation, and hydrology. A laurel (~lmia ?ngusfif~~_) is the domi classification like this is necessary for nant evergreen dwar -shrub in most bogs. a discussion of processes maintaining or In this case the soils are often sphagno changing these landscape units. All can fibrists. occur as di sti net, cl early recognizable landforms. Nevertheless, it should be Tall-shrub thicket ~ogs. Tall-shrub realized that not every peatland will fit Thlcket oogsaredom-1 nated by deciduous into one category. Some are composites of Pric:aceouc; c;hrubs, usuallv with black two landforms, e.g., a perched water bog spruce, larch and a few red maples (Acer may adjoin a lake-fi 1 l Dog. In other rub rum). Accardi ng to the FWS wet Tana cases, two types may grade into each classffication (Cowardin et al. 1979) other. For instance, the water movement these bogs are classified as Palustrine, through a soligenous mire can become so broad-leaved deciduous, scrub-shrub wet insignificant that it cannot be distin lands, saturated with fresh-acid water. guished from a perched water bog with They occur on medifibrists or hemists. stagnant water. The dominant high shrub is highbush blue berry (Vaccinium corymbosum); winterberry (I lex vert1clTlataT7aiiClominate on shal - lower peatan 6 LAKE-FILL PEAT DEBRIS FALLEN FROM PEAT MAT LAKE SEOIMfNTS-dy and gytt1a Figure 4. Types of peat bog-lake systems common in the region. Kratz and DeWitt (1986) provide further detail on the relation between peat types and lake-fill succession. The peat stratigraphy of moat bogs is poorly known. The diagram shows the probable sequence of peat types. Figure 5. Bog vegetation in center of former lake. The vegetation is dominated by Chamaedaphne calyculata with scattered larch, pitch pine, white pine, and red maple trees. 7 Moat bogs. These bogs differ from the 1.5.2. Perched Water-Peatland Systems lake-fill bogs in that a well-developed moat (Figure 6) separates the bog from the These occur in depressions and in val uplands. This moat is filled with water leys that have a perched water table that most of the time. The bog adjacent to the maintains conditions suitable for peat bog moat is usually a quaking, floating mat. development. They can be associated with The central part of the bog is grounded lakes, but their present development is and can be forested or have a dwarf shrub not controlled by a lake. These peat bogs vegetation. occur mostly in areas with shallow till or with compacted till. They receive water Pond-border bogs. These vary from from the surrounding uplands; this water narrow zones along the pond margin to peat either seeps through the bog or stagnates bogs that have almost filled a lake (Fig in the basin. They can occur also in val ures 7 and 8). The latter differ from the leys and flats underlain by sands and lake-fill bogs in that a part of the orig gravels if water is perched on interbedded inal pond is still present. The bog mat silt and clay layers, or if a reliable is floating near the center but grounded source of oligotrophic water is available. along the landward side. The vegetation of the floating mat adjacent to the lake is usually enriched by lake water and dif Conditions in these peatland systems fers from that of the remainder of the bog vary and depend mostly on the magnitude of mat. the water-1evel changes in the basin, the Figure 6. Moat of moat bog during period of low water in late fall. The tussocks in the moat are Carex stricta; stems of Typha angustifolia are visible, especially in the background. In the far background at the bog side of the moat is a tall-shrub thicket with Vaccinium corymbosum and Rhododendron viscosum (Congamond Lake Bog, CT). 8 Figure 7. Pond border bog with narrow strip of bog vegetation along opposite shore of lake !Gushee Pond, MA). Figure 8. Pond border bog with well·developed floating mat (Molly Pond, VTI. 9 $;:::hagnum are ·;:ri scussed nous rt of the region, water are so great able ic genous mires seldom oli become more common northward from surrounding iration losses decrease, and vegetation enriched by su us ncreases. Neverthe- the uplands. The width com mires are not common in the position of this border zone varies, but I until the climate is suffi this zone is usually forested. In ci ently d to allow raised bog forma with large water-level fluctuations, ti on. igenous mires can show a rather flooding can occur at times of high water, clear pattern in northern mainly in spring and winter. This has a Maine 1983; Sorensen 1986) major effect on the bog on. and very impressive patterns farther north {Figure 9). Soli s mires. The vegetation of these res can vary greatly depending on L 5.3. stems the size of the bog and the amount and nature of the seepage water entering the These are limnogenous mires flooded by mire. Only those with oligotrophic water a stream during high water. The water Figure 9. Soligenous mire with pronounced pool··string pattern. This is a small fen in the boreal forest of a hilly part of Western Newfoundland. The entire mire is influenced by minerotrophic water. Such mires occupy extensive areas on very gently sloping terrain. 10 chemistry and the duration, fn;quern.:~v, depth of flooding are the mary controlling the vegetation these Only those mires flooded by 0 l i 1. 5 .4. s Peatland stems water and ~ith ~p~agnu!!!_ as a cover are inclu e fiere. These are restricted to the northern part of the region and areas north of the L imnogenous peat bo~. They occur Cana di an border (Figure 10) . Their ombro along slow-flowing, nutrient-poor bog trophi c center is raised above the minero streams. As a rule, limnogenous peat bogs trophic bog border or lagg (Figure 1). are associated with other types of peat- T~e~r topography.depends ?n.climatic con 1ands. Their vegetation is usua11y domi ct·1t1ons, especially hum1d1ty (Gra~lu~d nated by leather leaf {Chamaedaphne caly 1932; Damman 1979a). Three major types of culata), sedges (Carex lasiocarpa),-or ombrogenous peatland can be recognized in dedduous dwarf shrubs su.ch·--as sweet gale the northeast. They show a clear zonation (t1yr_ica ~~_) or spiraea (Spiraea_ spp.). from the coast to the interior (Figure 3). Figure 10. Ombrogenous peatland with almost concentric pool pattern in the ombrotrophic center (east of Roebuck's Lake, Central Newfoundland). A minerotrophic mire vegetation (fen) in the lagg separates the raised ombrotrophic bog center from the uplands. This is clearly visible at the left and bottom of the photograph. 11 CHAPTER2. FACTORS PROPERTIES 2.1 SUBSTRATE peatlands, depending especially on aera tion and fertility of the peat horizons. Peatl ands have an organic soil result In addition, organic tissues decay at dif ing from the slow and incomplete decompo ferent rates. Wood and fibrous leaf bases sition of organic matter. The fact that are most resistant, and they may still be this organic matter has accumulated indi recognizable with the naked eye in peat cates that production exceeded decay dur thousands of years old. More importantly, ing the development of the peatland. How this differential decomposition can lead ever, this does not necessarily mean that to an overrepresentation of decay resis peat still accumulates in the peatland. tant materials, such as wood, in old peat horizons (Clymo 1983). Peat consists of the partially decom posed remains of plant material produced Peat is commonly classified on the by the present vegetation or by vegetation basis of its botanical composition and the that occupied the site during earlier degree of humification or decay. These stages of bog development. The nature of classifications compliment each other. the peat depends primarily on the type of plant material and the degree of decompo 2.1.1. Classification Based on Botanical sition or ultimately on the hydrology and Composition water chemistry of the site. Vascular plant material is added to the peat as Based on botanical composition, at leaf 1 i tter and as dead roots, branches least five types should be distinguished: and stems. In contrast, a moss carpet, such as that of Sphagnum, grows at the Sphagnum peat. This consists mainly surface and dies ar-~base. In many of the remnants of Sphagnum with varying peatlands, these moss carpets determine amounts of sedges as well as branches and the structure of the surface peat. rhizomes of ericaceous dwarf shrubs. This Lichens and liverworts also grow in this peat type develops in nutrient-poor peat way, but these plants decay so rapidly lands, such as ombrotrophic and oligo that they are an insignificant part of the trophic bogs. peat. Moss and moss-sedge peat. This is made up mostly of other, mainly hypnoid, The physical properties of peat change mosses and varying amounts of sedges. with time, i.e., with depth in the peat This peat is influenced by mineral-soil deposit, primarily because of decay and water, is more nutrient-rich than Sphagnum compaction. Decay breaks down the struc peat, and has a higher ash content. ture of the organic matter and increases the density of the peat. The weight of Reed and sedfe ~eat. Reed (Phrag- the overlying material compresses the peat mites), catta1lslyp al, and large sedges and also increases its density. As a make up the bulk oT"thls peat, which has a result, peat becomes denser and more humi high ash content and develops in eutrophic fied with age (Figure 11). This does not peatlands. always result in a uniform increase in hu midification with depth because of changes Woody peat. This develops under in growth and decay during peat bog devel forested peatla~ds, and contains undecayed opment. The rate of decay varies among wood. Woody peat is a heterogenous type, 12 Figure 11. Core sample collected in the surface peat of an Empetrum-Sphagnum fuscum vegetation of a coastal plateau bog. Peat becomes denser and more humified with depth. The surface peat is loose and well-structured, but at 35-40 cm the structure of the Sphagnum plants is no longer visible. The peat at 40 cm is about 90 years old and at the bottom of the sample (60 cm; extreme left) about 360 years old (M.F. Fitzgerald, University of Connecticut; pers. comm.). including peat developed under bo~ forests 2.1.2. Classification Based on Degree of with Sphagnum peat, fen forests with moss Decomposi t1 on sedge peat, and swamp forests with a well humified peat matrix. In dealing with Degree of decomposition or humifica woody peat, it is useful to recognize ti on of peat is often estimated according these three categories. to von Post's H-scale (von Post and Gran lund 1926). This scale is based on the Limnic peat. This is a sedimentary color of the water, structure of the resi peat--or-coprogenous sediment deposited in due, and amount of peat that passes lakes and other water bodies. It consists through the fingers when the fresh peat mainly of organic matter derived from sample is squeezed (Table 1). aquatic organisms or from aquatic plants. Gyttja and sapropel are forms of 1 imni c peat. The U.S. Department of Agriculture Soil Conservation Service uses fiber con The presence of layers of different tent to determine the degree of decomposi peat will affect the characteristics of tion in organic soils (histosols). Fibers the peat deposit and wi 11 reveal the his are defined as fragments of plant tissue, tory of development of the peatland. Con excluding live roots and wood fragments versely, a knowledge of the history of larger than 2 cm in cross section, that development helps in understanding the are longer than 0.15 mm. Partially hydrology of a peatland. decayed fibers can be easily broken by 13 Table 1. Peat humification scale (von Post scale) based on properties that can be observed in the field. Translated from von Post and Granlund (1926). ------·------·------~------· Scale Properties ------·---·------Hl Completely undecomposed peat; only clear water can be squeezed out. H2 Almost undecomposed and mud-free peat; water that is squeezed out is almost clear and colorless. H3 Very little decomposed and very slightly muddy peat; when squeezed, water is obviously muddy but no peat passes through fingers. Residue retains structure of peat. H4 Poorly decomposed and somewhat muddy peat; when squeezed, water is muddy. Residue muddy but it clearly shows growth structure of peat. H5 Somewhat decomposed, rather muddy peat; growth structure visi ble but somewhat indistinct; when squeezed, some peat passes through fingers but mostly very muddy water. Pressed residue muddy. H6 Somewhat decomposed, rather muddy peat; growth structure indis tinct; less than one-third of peat passes through fingers when squeezed. Residue very muddy, but growth structure more obvi ous than in unpressed peat. H7 Rather well-decomposed, very muddy peat; growth structure visi ble, about one-half of peat squeezed through fingers. If water is squeezed out, it is porridge-like. HS Well-decomposed peat; growth structure very indistinct; about two-thirds of peat passes through fingers when pressed, and sometimes a somewhat porridge-like liquid. Residue consists mainly of roots and resistant fibers. H9 Almost completely decomposed and mud-like peat; almost no growth structure visible. Almost all peat passes through fin gers as a homogeneous porridge if pressed. HlO Completely decomposed and muddy peat; no growth structure visi ble; entire peat mass can be squeezed through fingers. rubbing between thumb and fingers. There 2.2 PHYSICAL PROPERTIES fore, both rubbed and total fiber content need to be determined. Three major types of organic materials are recognized on the Physical properties of peat such as basis of their fiber content (Soil Survey water-holding capacity, permeability, and Staff 1975). Figure 12 shows the criteria hydraulic conductivity determine, to a used in defining them as well as some of very large extent, the hydrology of peat their properties. lands. These, in turn, depend on the 14 (g IOT l 1 l="IBR' I I\,.,r Cl) -E Figure 12. Properties of fibric, hemic, and sapric peat as defined by Soil Survey, Soil Conservation Service, U.S. Department of Agriculture. botanical composition and degree of humi grams also illustrate the effect of decay fication of the peat. on the waterholding properties of peat. 2.2.1. Water Content and Wa1:..~_Re~ntio~ Peat of different botanical composi tion differs in pore size and decay rate. Important are both the amount of water Therefore, the water-retention properties that the peat can contain and the tension di ff er among peat types. This relation at which water is held when the peat dries shi p is shown in Fi~ure 15. Water is held out. All saturated peat contains 1 arge at much lower tensions in poorly decom amounts of water. However, the amount of ~osed or undecornposed Sphagnum peat than water held at low tensions, which thus can in other peat types. lifevertheless, satu be easily removed, decreases with decay rated peats hold roughly equal amounts of and compaction of the peat. Boelter water, so the amount of water removed from (1968, 1969) clearly demonstrated how the saturated peat when the water table is amount of water held at various tensions lowered is much greater for the poorly changes with bulk density and fiber con decomposed surface peat of Sphagnum bogs tent of peat (Figures 13 and ~4). Since tryan for other peatlands. A rough-impres bulk density increases and fiber cont~nt sion of the differences in the amount of decreases during decomposition, these d1a- water that can be drained from various 15 Undecoyed Sphagnum peol Q) 1'.JC E (Hl+H2) :J Jv1oderately decayed herbaceous peat 0 80 r Poorly decoyed S phognum peat > (H3-H4) ::-\'. W ~ 60 1- (I) G Moderately decayed z peaT \ \ 100 SATURATED E ~ 40 :::J · "·-... __ S,pfl_agnum moss peat\\ z ~~---, \ \ 0 0 \I > (..) 20 \".-_-- ~ 0 ::... N X o~··-··--~·-················~····· 0.005 0.035 0.065 0.1 0.2 150 I-z 50 i.J..j WATER TENSION (bars) I- z 0 Figure 15. Water retention in different peats (after u Boelter 1968). The difference in the amount of water held by saturated peat (tension 0 bars) and drained 0 N peat at field capacity (about 0.1 bars) is largest for live 0 0.05 0.10 0.15 0.20 0.25 :r: Sphagnum moss and least for well-decomposed peat. BULK DENSITY (g/cm3) Figure 13. Relation between bulk density of peat and higher in peat. Assume a water tension of its water retention at various tensions (modified after 0.1 bars in fully drained peat; then the Boelter 1968). Notti that loose, poorly decayed peat quantity of water that can be drained from with low bulk density holds the most water at low saturated peat ranges from over 50% for tensions. the live, undecomposed Sphagnum peat to about 10% by volume for some of the other peat types. Water storage or water yield SAPRIC HEMIC FIBRIC coefficient, the volume of water removed E 16 gnum ss and S ge Peat ed and Sedge Peat r 6 I '< 0.. (/') 6 ..., a 'E 5 c f()(,) (/) (") (/') 0 b 5 (') I u 0 I 4 :J >. 0.. I c (") -> 4 I - ..0 0 -< -(.) Q) :J E 3 ""O lo- -Very Strong '<- c Q) 0 3 u 0.. -3 0 if) 0.. 2 'a 2 '<- -Strong -Moderate ...... Little -Weak 0 'Very Weak 0 0 2 4 6 8 10 Degree of Humification ( von Post scale) Figure 16. Relation between hydraulic conductivity and degree of humification of different peat types (redrawn after Baden and Eggelsmann 1963). The humification is based on the von Post scale (Table 1). The soil permeability classes are based on Sonneveld (1962, cited by Baden and Eggelsmann 1963). Wooded swamp peat not included because it is generally strongly to almost completely decomposed. except for wood fragments. 17 D- SWAMP PEAT REED AT E PEAT MOSS B SEDGE PEAT SPHAGHUM PEAT H3 HS HS HYDRAUUC CONDUCTIVITY (cm/s) Figure 17. Relation between hydraulic conductivity and peat types (graphed from data in Baden and Eggelsmann 1963). H3. H5, etc. refer to humification according to the von Post scale (Table 1). In wooded··swamp peat, there is no consistent relation between decomposition and hydraulic conductivity. is a rough indication of its ability of peat. Therefore, hydraulic conductivity, but the hydraulic conductivity of woody hydraulic condudivity of ~cats peat varies (Baden and Eggelsmann with the same H-value increases in 1963) and is higher than the cor the order: 2Phagnum peat, moss responding peat type without wood. sedge peat, seage peat, and reed This also explains why in wooded peat. swamps the degree of decomposition is a poor indication of hydraulic (3) Wood fragments increase the perme- conduc ti vi ty. 18 CHAPTER 3. HYDHOlOGY AND WATER CHEMISTRY 3. 1 WATER STORAGE and ecologically important properties of the substrate are associated with this Throughout the northeastern United subdivision (Figure 18). States precipitation exceeds water losses by evapotranspiration, at least on an Water is stored in the acrotelm. Most annual basis. However, during the summer of the changes in storage involve the free precipitation is often considerably less water in the zone of water-level fluctua than the evapotranspiration losses. This tion and the capillary water above the applies also to the zone with ombrogenous water table. Therefore, the depth and the bogs in northern Maine. Its southern physical properties of this -layer affect boundary in eastern North America (Figure water retention most. 2) occurs roughly where the cumulative deficiency of precipitation over potential The catotelm is constantly saturated evapotranspi ration exceeds 100 mm ( Damman with water, and therefore one would not 1977). When potential evapotranspiration expect any changes in water storage in exceeds precipitation, the vegetation will this layer unless the peat bog is drained. draw on water stored in the ecosystem or Although this appears to be generally supplied from other sources. This will true, it does not apply to all bogs. In often result in a lowering of the water lake-fill bogs, a layer with loose, sus table during the summer and early fall. pended organic matter occurs often at 1-2 m below the surface. During dry periods, Water is stored in the peat, in pools this layer shrinks because water is with on the bog surface, as snow, and as inter drawn from it. This causes seasonal cepted water on the vegetation. The first changes in surface level of these bogs two storage forms are most important dur similar to, but less dramatic than, those ing summer. The amount available in each in the floating mat of pond-border bogs. depends on the physical properties of the There is also evidence of changes in sur peat and the microtopography of the bog face level from bogs with solid peat surface. Bogs are saturated with water deposits (Ganong 1897; Uhden 1956; Eggel for most or all of the year. When satu smann 1960). These surface level changes rated, their storage capacity is filled, appear to be due to expansion of the peat and no additional water can be stored. during wet periods, perhaps due to The available storage capacity increases increases in hydrostatic pressure (Ingram during the summer and will be highest at 1983). Increases in water content of the the lowest water 1eve1 . In genera 1 , the catotelm were also observed by Heikurainen water storage capacity of bogs is overes et al. (1964). timated. In spite of popular belief, bogs regulate stream flow only to a limited extent, especially in humid areas (Goode 3.2 WATER MOVEMENT IN BOGS et al. 1977). 3.2.1. Lateral Flow It is useful to di sti ngui sh two major peat horizons: the acrotelm and catotelm. Within the acrotelm, the hydraulic The former is the surface peat above the conductivity decreases with depth because low-water table, and the latter is the of decay and compaction of the peat. The permanently anaerobic peat below this reduction in hydraulic conductivity from level (Ingram 1978). Many hydrologically the surface to the base of the acrotelm 19 0 - Variable water content E - Variable aeration (.) 2 w 20 -Biologically most active _J u w ~ . HOLLOW SURFACE -Hydraulic conductivity high, decreases r er: downward o :::> 0::: Cf) u :::x:: I water movement 5: ~...... ~---~..;...... ,;...;;.~ LWT ---- sw CD 60 -Permanent I y saturated with water 2 I _J f- -Hydraulic conductivity very low w CL w ( 0. 2 - 5 x Ic5 5 cm I sec ) 5 0 ~ -Water movement negligible u 80 -Permanently anaerobic l_ -Very low biological activity 0 50 100 HWT = HIGH WATER TABLE PERCENT OF TIME LWT = LOW WATER TABLE Figure 18. Properties of acrotelm and catotelm of peat bo9s. The heavy black line in the stippled horizon is the water level duration curve, indicating the percentage of time that the water table is at or above that level. tends to regulate water levels by increas show a more rapid reduction in hydraulic ing flow at high-water levels and reducing conductivity with depth than do ombro flow at low levels (Ivanov 1975). Conse trophi c bogs. Thus, Sphagnum peat i nfl u quently, water levels remain mostly around enced by weakly mi nerotroph1 c water can average levels and reach peaks for brief change within 25 cm from a layer of sur periods only. This is best expressed in face peat with Hl or H2 according to the ?Ph_a.9._num peat of ombrotrophic bogs (Figure von Post seal e (Tab le 1) to H4 or H5. In nn, wnere the acrotelm is thick and the red maple and cedar swamps, peat with H6 peat poorly decor.nposed. In many oligo often occurs at the surf ace of the troph1c bogs this regulation of water depressions. levels is less effective because of rapid decay of the peat or impeded drainage. Information on the relationship between hydraulic conductivity and botani Small increases in nutrient level can cal origin of the peat should be applied greatly increase decay of the surface cautiously to field conditions. For peat. Therefore, mi nerotrophi c peatl ands instance, Sphagnum peat at H3 or over has 20 lower ities than other occurs, ana wai::er t1ows mainly ovet the However, the liv- surface and through cracks that develop in ng and making the during drying. the surface a very porous s tu re with ic matter occupy; ng Capillary water rises higher above a less than 20% of volume (Clymo 1983), water table when pore size becomes so water can move dly (Figure 19). In smaller, but at the same time this reduces contrast, a layer with comparable perme the rate of water movement. The capillar ability is absent in most swamps and ies through which water moves in peats are marshes, and peat with H3 or over may so small that the upper 1 imit of the occur at the surface. Therefore, flow capillary zone is limited mostly by evapo through the Sphagnum peat can exceed that ration at the surface and uptake by vege in other peatlands. Decay rates vary tation. Sphagnum plants lack vascular greatly among peatlands, and to avoid tissue, and therefore water movement to erroneous conclusions such changes should the surface of a Sphagnum carpet is by be considered in evaluating water move physical processes.----on--a-sunny day, eva ment. When the water table rises above poration losses can easily exceed trans the surface, water will drain rapidly port of capillary water to the surface, from the peatland unless topography and the Sphagnum surface will dry. The impedes drainage. evaporation -rate at the surface depends also on the morphology and anatomy of the Impeded drainage from the peatland can Sphagnum species (Figures 19, 20, 21, 22, cause high water tables in parts or all of and 23) and the density ot the carpet a peatland. Consequently, water tables (Overbeck and Happach 1957; Hayward and can be close to the surface in spite of a Clyrno 1982; Rydin and McDonald 1985; high hydraulic conductivity of the peat. Andrus 1986). Drying out of the surf ace Under these condi ti ans water-1 evel fl uctu is, therefore, only partly controlled by ati ons depend on the balance between water the depth of the water tab 1 e (Neuhaus l losses (drainage and evapotranspiration) 1975). and inputs (precipitation, seepage, and possibly stream inputs). 3.3 WATER CHEMISTRY 3.3.1. Chemical Differences Between 3.2.2. Vertical Flow Meteoric and Tel luriC Water Water movement driven by gravity and Water in bogs comes from the atmos evaporation are important above the water phere and the surrounding uplands. Atmos table. This involves percolation of pre pheric (meteoric) and terrestrial (tel cipitation through the surface peat and luric) water differ in chemical upward movement of capil 1ary water; both composition. It is important to distin play a role in translocating elements. guish these two sources when dealing with peatlands because their relative contri Percolation of rain water through the bution varies within a peatland and among peat depends on the permeability of the peatlands. peat. It is controlled by the same pro cesses that affect hydraulic conductivity. Some nutrients and other elements in Water percolates easily through the live precipitation are derived from the sea, and undecomposed Sphagnum peat but very but to these are added elements contrib slowly through we"ll-decomposed peat. If uted by atmospheric pollution and natural surface peat is well-decomposed, the water fires as well as those in soil and organic level is usually near the surface, and dust, mostly from agricultural areas (Gor puddling on the surface is frequently due ham 1961). The ionic composition of pre to a rise in water 1eve1 . We 11 -decomposed cipitation depends on the relative contri peat can be found above the water table in bution from each of these sources, and it drained peatlands and in bogs with shows clear geographic trends (Mun~er and strongly fluctuating, perched water Eisenreich 1983). Precipitation in the tables. Under such conditions puddling northeastern United States is strongly 21 Figure 19. Loose surface peat with Sphagnum magellanicum and S. angustifolium. The surface peat is very porous, especially below the capitula (heads) of the Sphagnum plants. modified by pollution, and to a lesser (Table 2). Foremost among the latter are extent, by agricultural dust. Therefore, Al, Si, Fe and Mn. Conversely, Na and Cl precipitation is greatly enriched with occur in much higher concentrations in heavy metals (Groet 1976) and sulfur and seawater than in freshwater (Table 2). nitrogen compounds (Junge 1958; Cormnittee The ionic composition of telluric water on Atmospheric Transport 1983). The depo depends on the type of rock and the length sition of all of these decreases roughly of time the water has been in contact with from south to north. Soil-derived ele it. Consequently, ionic composition var ments such as Fe, Mn and Ca, are present ies geographically and temporally. Ionic in low concentrations compared to other concentrations are lowest in areas with parts of the United States (Munger and poor soils and rocks such as sandstones, Eisenreich 1983). schists, or granites and during periods of heavy flow. Superimposed on this varia Soil water is rain water that has been tion are changes due to biological pro in contact with the mineral soil or bed cesses such as decay of organic matter and '.ock. .While seeping through the soil, it uptake by vegetation. 1s enriched with elements supplied by weathering, solution, hydrolysis and 3.3.2. Chemical Composition of Ombro- cation exchange. This enrichment results trophic Bog Water in higher concentrations of most elements in te11uric water than in rain water The ionic concentration of water especially of those elements occurring ;~ derived from precipitation changes after large amounts in soils and rocks but in it reaches the bog surface, even without very low concentrations in sea water coming into contact with telluric water. 22 Figure 21. Sphagnum papillosum Lindb. (a) cross sec tion of branch leaf, (b) convex surface of branch leaf Figure 20. Sphagnum magel/anicum Brid. (a) cross as seen on electron microscope, (c) stem cortex, section of branch leaf, (b) branch leaf, (c) stem leaf, (d) branch leaf, (e) stem leaf, (f) cross section of (d) branch cortex, (e) cross section of stem. stem. Evapotranspiration at the bog surface, in the precipitation (Table 3). Other leachates from vascular plants, and decay ions do not show this increase, because of organic matter increase concentrations, they are removed by uptake or cation whereas adsorption on peat and uptake by exchange (Darrman 1986). Seasonal varia plants lower them. Most of these pro tions in ionic concentrations are espe cesses are temperature dependent, and cially large for mobile ions such as K therefore the concentrations of most ele that can occur in concentrations below ments vary seasonally (Damman 1986). that in the precipitation during periods of active growth (Damman 1986), whereas concentrations reach high levels in early Evapotranspiration increases the ionic fall when it is leached from senescent and concentration of an element if the biolo dead leaves (Malmer 1962b; Damman 1986). gical demand for the element is low, as Ionic concentrations in ombrotrophic water for Na or Cl (Damman 1986). Even in are closest to that in the precipitation humid climates their concentration in during periods of heavy rain or snow melt ombrotrophic bog water is many times that and deviate most during hot, dry spells. 23 Figure 23. Sphagnum rubellum Wils. (a) cross section of branch leaf, {bl stem leaf, {cl branch leaf, {dl cross Figure 22. Sphagnum fa/lax {Klingr.l Klingr. {al cross section of stem. section of branch leaf, {bl stem leaf, {cl branch leaf, ldl cross section of stem. The ionic composition of mineral soil water flowing through a peatland is 3.3.3. Chemical Composition of Minero affected by the same processes discussed trophic Bog Water under ombrotrophi c water. In addition, dilution by rainwater plays a major role The effect of the mineralogy of soils here. The relative importance of evapo and bedrock on the ionic composition of transpiration and dilution by rainwater on telluric water is well documented (Clarke the ionic concentrations is controlled by 1924; Troedsson 1952; Gorham 1961} and climate, but in bogs receiving seepage causes major differences in the chemistry water it depends also on the dimensions of of the water seeping into peatlands. Even the peatl and. on nutrient-poor sands the concentration of most nutrient elements is much higher Size of a peatland will affect sur than in the precipitation (Table 3). This face-dependent factors such as precipita is especially true for elements virtually tion and evapotranspiration to a much absent in seawater such as Fe, Mn, and Si. greater extent than border-dependent fac- 24 ~ atlle L. fne relative concentrations of the mmn <1oum:iant eitimt:inis in tht. earth crust, soil, and water, excluding C, Hand 0. Values are percent (weight basis) of the total amount, calculated from mean and median concentrations reported by Bowen (1979). -~----"·-~----·------· Element Earth crust Soi 1 s Freshwater Sea water ______.. Al 15.9 14.5 0.64 6 x 10-~ Ar 0.0002 1.2 1 x 10- B 0.002 5 0.004 0.03 0.01 Br 7 x 10- 0.002 0.03 0.2 Ca 7.9 3.1 33.2 1.2 Cl 0.03 0.02 15.0 58.3 Fe 7.9 8.2 1.0 6 x 10-6 K 4.1 2.9 4.6 1.2 Mg 4.5 1.0 8.5 3.9 7 Mn 0.18 0.20 0.01 6 x 10- Na 4.5 1.0 12.9 32.4 p 0.19 0.16 0.04 0.0002 s 0.05 0.14 7.9 2.7 Si 53.7 67.4 15.0 0.007 Sr 0.07 0.05 0.15 0.02 6 Ti 1.1 1.0 0.01 3 x 10- N 0.005 0.41 0.10 1.5 x 10-4 Table 3. Comparison of ionic composition of precipitation with that of ombrotrophic bog water and minerotrophic brook water for a peat bog at Stephenville Crossing, Newfoundland (May-September 19801. Mean concentra tions ± standard error. Based on data in Damman (1986) and unpublished data. Element (ppm) Water characteristics n K Mg Ca Na Fe BULK PRECIPITATION Volume weighted mean 27 0.065 0.12 0.52 0.75 0.052 Unweighted mean 27 0.062±0.007 0.12±0. 02 0.53±0.09 0. 63±0.11 0.052±0.008 OMBROTROPHIC Pools on plateau bog 48 0.10±0.02 0.46±0.02 0.25±0.02 3.89±0.10 0.065±0.009 Bog brook 16 0.17±0.06 0.52±0.03 0.27±0.01 3.81±0.12 0.079±0.008 MINEROTROPHIC Brook through nutrient- 7 0.22±0.03 1.11±0.06 2.80±0.36 5.76±0.26 0.47±0.07 poor outwash Regional brook 8 0.63±0.03 4.5±0.2 18.5±1. 0 6.18±0.20 0.18±0.03 25 tors such as seepage. This is especially the di stance the This noticeable in soligenous peatlands, which effect is greatest in humid cl tes, receive mineral-soil water mostly as seep where these peatlands are most common. age water rather than ground water. Tn During the fall, 1eachates from dead and sue~ peatlands, the diluting effect of senescent foliage will partly offset the rain on ionic concentrations increases lowering of ionic concentrations by rain rapidly with the size of a peatl and and fall and uptake by the vegetation. 26 CHAPTER 4. STORAGE AND FLUXES OF ELEMENTS 4.1 lNTRODUCIION 4.2 ENERGY FLOW Our knowledge of energy flow and ele There have been no complete studies of mental fluxes in peat bogs is incomplete; ener$Y flow in peat bogs. The studies this is especially true for North American prov1 ding the most deta i1 ed information peatlands. Quantitative data on elemental were part of the International Biological fluxes are virtually lacking for peat bogs Program (IBP) Tundra Biome Project in in the northeastern United States and the Moore House, a British blanket bog (Heal situation is hardly better for information and Perkins 1978), and a subarctic mire in on amounts stored in the peat. Hemond Swedish Lapland (Sonesson 1980). (1980, 1983) provided estimates of fluxes for some elements in a kettle-hole bog, The primary production of vascular and Damman (1979b, 1986b), Laundre (1980) plants, liverworts, mosses, and lichens in and Lyons (1981) showed amounts stored in the bog vegetation provides the major the peat. input of organic matter. Additional inputs come from phytoplankton in bog pools and organic matter blown or washed in from areJs outside the bog. The Extrapolation from data outside the latter can contribute considerably in region is complicated by differences in sma 11 peat bogs, but its role decreases vegetation structure and climate, espe with increasing size of the peatland. cially those affecting hydrology. For Little is known about phytoplankton example, it is difficult to extrapolate productivity in bogs. This input from data for a well-studied, forested, increases with fertility of the peat land perched peat bog in Minnesota (Verry 1975; and with wetness, especially with the Verry and Timmons 1982; Urban 1983; Grigal surface area of open water. Presumably, et al. 1986; Urban et al. 1986) i nfor input from this source is sma 11 in bogs mat ion pertinent to open or shrub-covered of the Northeast. bogs in the Northeast. In addition, the bogs within the region vary with respect Among the vascular plants, ericaceous to hydrology and inflow, and therefore dwarf shrubs and sedges (Cyperaceae) are they by no means represent a homogeneous the most important primary producers (For group as far as fluxes are concerned. rest and Smith 1975; Svensson and Rosswall 1980), and much of this production is below-ground (Svensson and Rosswall 1980; This section is mainly on data col Wallen 1983). Trees can al so be major lected elsewhere and interpreted in the contributors in some bogs. light of our understanding of ecological processes in bogs. Therefore, this dis cussion is, to some extent, speculative. Productivity is rather low compared It indicates the general trends within the with other ecosystems (Reader and Stewart peat bogs of the Northeast and the 1972; Forrest and Smith 1975; Grigal et expected geographical variation. More al. 1986), but mosses and especially over, it points out how processes in peat Sphagnum, can account for 1/3 - 1/2 of the bogs differ from those in the more total production (Forrest and Smith 1975; famil iar upland ecosystems. Grigal 1985), and probably more in some 27 plant communiti7s. Pre~umab'.y, prorluctiv 4 3 F! ... IJXt=S OF NUTRIENTS AND OTHER ity increases with nutr1~nt input c:nd gen ELEMENTS erally with inputs of mineral soil water into the peatland. land Herbivory is much less important in peat bogs than in other wetlands (Cragg Peat bogs are characterized by slow 1961; Svensson and Rosswall 1980; Mason decay of organic matter. This partially and Standen 1983), presumably because the decayed litter forms the substrate in organic matter of bogs is nutrient defi which plants root, and it also seals off cient (Bellamy and Rieley 1967; Small tbe vegetation from direct contact with 1972; Damman 1978a) and the litter of the the mineral soil. Therefore, organic mat vascular plants is often sclerophyllous ter that is at the surface at any one time (Small 1973). Herbivory probably will gradually be buried under more and increases with the fertility of peat bogs. more peat as the moss layer continues to grow. Peat bogs are detritus-based eco These conditions have several imp1 ica systems, and breakdown of organic matter tions for nutrient cycling that distin is of major concern. Bacteria and fungi guish peat bogs from upland sites: make up the major part of the decomposer complex (Svensson and Rosswan 1980). Fungi are mostly restricted to the aerobic (1) Nutrient turnover is slow because peat, and Svensson and Rosswa11 (1980) of nutrient deficiency of the litter and found 90% of the myce l i um in the upper water-logging of the substrate. There 10 cm. Most decay also takes place above fore, in actively growing peat bogs the the water table (Clymo 1965; Malmer and detritus cycle is poorly developed. Nut Holm 1984). rient cycling increases when peat growth stagnates, and it is also more active in bogs receiving higher nutrient inputs. Peat could not accumulate if produc (2) The amount of nutrients in the tivity did not exceed decay. Although living biomass is small, but the amount this has to be true over the entire period stored in undecayed organic matter is far of bog development, this does not mean larger than in other ecosystems (Darnrnan that productivity still exceeds decom 1978a). position. As long as accumulation takes place below a water table, decay will be (3) Nutrients in peat below the root very slow (Clymo 1965), and peat will ing zone of the vegetation are unavailable accumulate in the bog. This situation to plants. Consequently, in bogs that clearly exists in may bog-lake systems actively accumulate peat, nutrients are that have not filled in completely. Above continuously lost to peat stored below the a water table, decay is accelerated, and rooting zone. This accumulation rate gene'.ally, an equili~rium between pro changes during bog development and varies duction and decay is reached within spatially and temporally in existing bogs. 30-50 cm above the water level, unless the extreme nutrient deficiency of the (4) Organic matter that makes up the pec:t limits decay (Damman 1979a, 1986). surface changes its position with respect '.his c.an l.ead to .a .raised bog formation to the water table over ti me. Thus, if climatic cond1t1ons cause a water organic matter appears to migrate with mound to deve 1op in the accumulated peat time from an aerobic horizon to one that pvanov 1981; Ingram 1983). This happens is periodically anaerobic to a perma in the zone of ombrogenous bogs in nently anaerobic horizon. This causes northern New England (Figures 1 and 2). redox-sens it i ve elements, as well as Even in this case, there is a limit to several other elements, to behave dif peat accumulation (Damman 1979a; Clymo ferently in organic soils than in mineral 1984). soils (Darnrnan 1978a). 28 ons of tnese elements in the bog water. This is especially noticeable for elements The meteoric of dust and rain is that are in short supply and for which the re·lati more t as a nutrient biological demand is large. In ombro source in peat than in other ecosys- trophic bogs, 70%-80% of the K and 20%-30% tems because of of inputs by of the Mg is removed while water seeps mineral ng and the generally small through the bog (Damman 1986). Similar telluric i The importance of mete- seasonal changes occur in N, P and Ca oric i increases as the decay rate of {Boatman et al. 1975), although changes in organic matter decreases and nutrient Ca are less conspicuous because Ca adsorp deficiency increases. Meteoric input is tion on peat is far more important than uptake by vegetation (Damman l986i. ~~:mi~~l ~i~f~r~~c~~bb~~:~~~ict~lf~~ic !~~ Potassium concentration in bog water peaks meteoric water were discussed earlier. in early fall when K is leached from dead and senescent plants (Malmer 1962b; Damman Small bogs and bog borders receive 1986). Elements released mostly by micro significant additional inputs of nutrients bial decay, such as N and P, do not show from litter blown in from adjacent this so clearly. Such seasonal fluxes uplands. Import or export of nutrients by occur in all bogs, but their effect on birds and mammals is unimportant in most water chemistry is less obvious when nut bogs (Crisp 1966; Svensson and Rosswall rient inputs are higher. 1980). Conspicuous exceptions are bogs used as roosting pl aces by waterfowl or Sulfate concentrations are highest in sea birds. bog water during the first rain after a dry spell as H2s, oxidized to H2so4 when Nitrogen fixation by free-living the water leveT was low, is flushed out of micro-organisms appears to be insignifi the bog. This flushing of sulfates occurs cant (0.07-0.150 g N/m2/yr) in ombro in a wide range of mires (Gorham 1956; trophic bogs (Granhall and Selander 1973; Mal mer 1974), but presumably it is most Waughman and Bellamy 1980) but becomes pronounced in bogs experiencing large more important in minerotrophic mires. water-level fluctuations. Hem2nd (1983) reported an input of 1 g Nim /yr for an oligotrophic kettle-hole Reduction of Fe and Mn compounds dur bog and Waughman and Bellamy (1980) f2und ing wet periods increases their solubility an average input of 0.53 and 2.1 g N/m /yr and exposes them to removal in the drain in poor and intermediate fens, respec age water from the peatlands (Damman tively. These values probably represent 1978a). Iron concentrations increase the upper limit of what can be expected in slightly in the drainage water of ombro the bogs discussed here. trophic bogs during high water levels in fall (Damman, unpubl.). This effect Symbiotic nitrogen fixation in bogs is should be most obvious in bogs receiving limited to actinomycetes associated with tell uric input. Myrica and Alnus. These species do not occur in the most nutrient-poor bogs of The concentrations of ions for which the region. In minerotrophic mires N the biological demand is low or negligible input from this source can be important. increase during warm and dry periods Schwintzer (1983) reported an addition of because of water losses by evapotranspira 3.53 g Nim 2/yr in an oligotrophic Sphagnum tion. This increase is most clearly shown bog with !:1:¥.!ic~ _g_ale. ·----- by Na and Cl (Gorham 1956; Boatman et al. 1975; Damrnan 1986). 4. 3. 3. TelllJ?oral Changes in Elemental Fluxes 4.3.4. Accumulation of Elements in Bogs Seasonal changes in biological pro Elements are stored primarily in the cesses and periodic changes in water 1evel living biomass of the primary producers are reflected in the elemental fluxes. and in the peat. The latter includes ele Active growth and uptake of essential ele ments in undecayed organic matter and in ments by the vegetation lower concentra- the microbial biomass as well as ions 29 adsorbed on the cation exchange complex ~f afte~ the less thAn ?O the peat. Some e 1ements a 1 so occur. in (Damman 1987). rable to precipitated salts. Ionic C?n~en~rat1?ns changes in most ant itter. In in the bog water are in equ1l1br1um ~ith ombrotrophic , lization also ions adsorbed on the peat; concentrations occurs (Malmer and Holm 1984), but it is are relatively low in bogs but increase limited by the deficiency of other ele with the input of fertile, mineral-soil ments. N concentrations water. decrease initially with depth, then increase slightly and generally stabilize Storage of elements in the living ve~ at C/N quotients over 50 (Damman 1988). etation varies with its biomass, and 1t This corresponds roughly to peat with less affects mostly the major nutrient ele than 1.2% N (Figure 24)_ ments. The amount is generally low com pared with other ecosystems, but it is Most bogs discussed here fit between large in relation to inputs, especially in the strongly minerotrophic and the ombro ombrotrophic bogs (Damman 1978a; Malmer trophic peatlands. It is unlikely that and Nihlgard 1980). In bogs, N, P, and K C/N ratios will drop much below 30 in any are strongly conserved in the living of the peat bogs in the Northeast. In the S~hagnum plants (Damman 1978a; Pakarinen oligotrophic floating and quaking bog-lake 1 78a; Hemond 1980) and in the actively systems, N concentrations in the upper growing parts of vascular plants (Small part of the bog mat (Figure 24) change 1972; Malmer and Nihlgard 1980), as they with depth almost as in ombrotrophic bogs, are in upland vegetation. but they increase abruptly in the gyttja deposited below the mat (Damman 1988). Enormous amounts of organic matter can accumulate as peat in bogs. In spite of Phosphorus accumulation in the peat the slow decay, and in contrast to popular shows a pattern similar to that of N, belief, many elements are removed from the although the actual amounts of P are much peat before it becomes anaerobic (Damman smaller than for N. Magnesium and Ca are 1978a). The extent to which nutrients are also retained in the undecayed peat, but retained depends mostly on the element and for these ions adsorption on the cation the time the peat remains above the summer exchange complex of the peat appears water level. Nevertheless, storage can be important. Magnesium can accumulate con considerable, because of the large amounts siderably in Sphagnum peat (Damman 1978a; of peat, even for elements present in low Hemond 1980). ata on other peat types concentrations. Accumulation in this eco are few (Mornsjo 1968; Tallis 1973; Lyons system compartment increases with the rate 1981), but concentrations appear similar. of peat accumulation in the bog. This They are usually about 1 mg Mg/g in the applies particularly to elements stored in deep peat except in inland regions where organic form in undecayed peat. the concentration in ombrotrophic peat can be much lower (Damman, unpubl.). Calcium Large amounts of C, N, and P are is also stored in large amounts in the stored in the undecayed peat, but almost peat. Concentrations are lowest in ombro all of the N and P is unavailable to trophic Spha~num peat of oceanic areas plants.. Carbon accumulation is directly (Damman 1978a and increase with distance proportional to the amount of organic mat from the coast. They are much higher in ter stored and depends on productivity and peat influenced by mineral soil water decay. !he same applies to N, but the (Mornsjo 1968; Tallis 1973; Lyons 1981). accumulation process is more complicated because of immobilization of N in the Several elements are removed from the microbial biomass. Therefore N concen peat before it becomes anaerobic, and they trations in the peat can vary 'among peat accumulate in the zone of water level lands. fluctuation (Fe, Al, Zn, Pb) or just above it (Mn) (Damman 1978a). In ombrotrophic In nutrient-rich, minerotrophic peat bogs their concentration is very low in lands, N concentrations increase with the anaerobic peat. However all, except depth because of N immobilization in the Pb, occur in much higher concentrations in peat and generally remain rather constant peat influenced by mineral soil water 30 ('\ I() ~)0 r '"'-' ~ mg Nlg ~--~-""""""·--,------~ -~"~ CI N RATIO ...... -E :I l a.. w 0 4 +-""+----"""-""---~ DUNHAM POND SWAMP BECKLEY BOG, STEPHENVILLE XING, CONNECTICUT CONNECTICUT NEWFOUNDLAND ~WATER WITH SUSPENDED --- ORGANIC MATTER BJ MINERAL SOIL BETHANY BOG, CONNECTICUT Figure 24. Nitrogen concentration and C/N quotient in cores from an oligotrophic lake-fill bog (Bethany Bog). an oligotrophic floating mat (Beckley Bog), a mesotrophic red maple swamp (Dunham Pond) and an ombrotrophic bog (Stephenville Crossing). High water table (HWTl and low water table (LWT) are shown; 50% water table is the level at or above which the water table occurred for 50% of the 1980 vegetative season. (Darnman 1979b; Laundre 1980; Damman and 1978b; Damman 1979bi Laundre 1980). liv Dowhan 1981) and in other peat types itt et al. (19791 and Hemond (1980) (Mornsjo 1968; Tallis 1973). Conse attributed the low Pb concentrations at quently, the concentrations of these ele greater depth to lower Pb fall-out at the ~ents in the peat vary among bogs, depend time the older peat was deposited. How ing on mineral soil water input and ever, this historical pattern seems to be water-level fluctuation. usually overruled by the water-level effect (Damman 1978a). Even in isolated ~ead is derived mostly from atmos Southern Hemisphere bogs, which have not pheric pollution. Therefore concentra experienced an increase in Pb pollution, tions in and above the zone of water-level Pb concentrations are highest in the peat fluc~uatio~ vary regionally, but concen above the low water-level (Damman, trat~ ons in the deeper, anaerobic peat unpub 1.). Apparently, Pb accumulates in remain very low (Damman 1978a; Pakarinen the peat of floating or quaking-bog mats 31 because of wiLn an aimosL sLctole wctLer Hemond' s { ) data. water ration. Sodium way (Boatman Sodium occurs in low ons in et a·!. 1975; 1986), but more of the anaerobic ( Tallis this el in the peat and 1973; Damman , 1979b; l, biomas Tallis 1973; Damman 1 ) . and amounts stored are relatively 1 · The same app l i es to K, that its concentration can be high in peat influ enced by mineral soil water (Mornsjo 1968; Most K leaves the in ionic form Tallis 1973). (Verry 1975; Burke 1975; Damman 1986}, a1thcu c~~sp 11%1)1 0lsf\ f01md large 4.3.5. Elements Removed from Peat s losses of K in particulate organic matter in an eroding blanket bog. The ability of Removal of elements, like their stor bogs to retain K is limited since storage age, depends on peat accumulation and bog is mostly in the living biomass. This is type. Interpretation of the 1 iterature is also documented by the large losses of K further complicated by unknown inputs in after fertilization (Burke 1975). Under all but the genuinely ombrotrophic bogs, undisturbed condtions, K losses are larg as well as by seasonal variation in ionic est from peatlands receiving substantial concentrations of the drainage water that mineral soil water inputs. is rarely accounted for. Presumably, out puts will equal inputs as production equals decay, and no further bog growth Magnesium occurs in ionic form in the takes place. However, this can require drainage water, but it is also strongly very long periods. adsorbed on peat particles. The 1 imited data on Mg outputs seems to suggest large Low concentrations of dissolved N are regional differences. Apparently, losses present in the drainage water from bogs, in the drainage water are smaller in and almost all of it occurs as NH ions inland areas {Hemond 1980; Vitt and Bayley (Boatman et al. 1975; Urban 1983; v;h and 1984) than in oceanic regions (Boatman et Bayley 1984). Most N appears to leave al. 1975; Damman 1986). bogs as particulate organic N (Crisp 1966; Urban 1983) and probably also in dissolved organic matter. Denitrification losses Most bogs are deficient in Ca and much from bogs are not well documented, but of the input is retained (Boatman et al. they are probably small, since nitrate 1975; Vitt and Bayley 1984) mostly by concentrations are low and the pH is too cation exchange (Damman 1986). Even a low for nitrification (Rosswall and Gran fertilized blanket bog (Burke 1975) lost hall 1980; Hemond 1983). Urban (1983) only 4% and 8% of the added Ca from a attributed about 25% of the N output to drained and undrained area, respectively, denitrification, but this appears too high in the two years following fertilization. for most peat bogs. Both denitrification Calcium concentrations are low in drainage and losses of dissolved N are more impor water from nutrient-poor and actively tant in peatlands with large nutrient growing peat bogs. They increase as tel inputs. About 20% of the N added was lost luric inputs increase. Among undisturbed in the drainage water during the 2 years bogs, higher concentrations can be following fertilization of a blanket bog expected in drainage water from bogs in (Burke 1975). inland areas than in coastal regions . . _LJptake of Cl by the vegetation is neg l 1g1ble and, as an anion, it is not Phosphorus concentrations in bog water a?sorbed on ~he peat. Therefore, reten are low, and most P appears to be removed ~1on of Cl in.bogs is limited and mostly in particulate organic matter (Crisp in the water in pools and peat. It is 1966). Large amounts of Pare stored in flushed ?ut at about the same rate it the peat, but the capacity of bogs for enters (Vitt and Bayley 1984). In large storage of additional amounts seems very bogs, Cl concentrations increase as the limited (Malmer 1974; Burke 1975). 32 Urban et al. timated that Concentrat1 ons ot- elements der1 ved 60%-93% of the ·1 oadings are mainl from mineral soils such as Fe, Mn, retained in eastern North America. and are hi in nage water of Retention is related to water- bogs rece1vrng luric water. Lead level fluctuations with y wet occurs in bog water in much lower concen bogs storing more .s than those with trations than in rain water (Hemond 1980), strongly fluctuating water levels. and input in runoff and seepage from upland areas is negligible (Damman 1979b). Regional differences in so4 inputs from air pollution are large (U.S.-Canada Work The distribution of Pb in peatlands (Dam group 1982; Munger and Eisenreich 1983), man 1978a; Laundre 1980) suggests that the and this is reflected in concentrations in highest concentrations can be expected in the drainage water from bogs. drainage from bogs witn high water 1evels. 33 CHAPTER 5. PEAT BOG VEGETATION 5.1 FLORISTIC COMPOSITION OF THE This lack of information hampered the PLANT COMMUNITIES preparation of this section, which is based primarily on 11\Y own unpublished data Vegetation changes within a bog and supplemented with whatever could be the differences among bogs are controlled gleaned from the literature. Most helpful primarily by habitat conditions, espe in this respect were the studies by cially hydrology and water chemistry. Nichols (1915) and Osvald (1970), both Climatic differences are reflected in the carried out in the early part of this cen floristic composition of the vegetation of tury. comparable habitats in different parts of the region. This co1t111unity profile Five major physiognomic vegetation includes parts of three vegetation zones units can be recognized in peatlands: for (Figure 2) and geographic changes in flor est, tall-shrub thickets, dwarf-shrub istic composition can be considerable. heath, vegetation dominated by grass-like plants (graminoids), and carpet or mud This section describes the major habi bottom vegetation. In topogenous peat tat-related variation in the peat bog veg lands, the first three make up most of the etation, including the major geographic vegetation. The last two play a minor changes within the region. The distribu role here, but they cover large areas in tion of the plant conmunities within the soligenous and northern ombrogenous peat major peatland types is discussed in the lands (Sjors 1961; Damman 1978b, 1979a; following section. Glaser et al. 1981). Within the north eastern United States, they are important only in fens (Osvald 1970, Sorensen 1986) The literature on peatland vegetation and in the plateau bogs along the north is fragmentary and inadequate, especially east coast of Maine (Damman 1977). that on topogenous peat bogs. Reports on the vegetation of individual peat bogs On ombrotrophic peat the occurrence of have been numerous, but they consist these physiognomic vegetation units is mainly of incomplete species lists, some closely tied to the depth of the water times with brief, superficial descriptions table (Malmer 1962a, Damman and Dowhan of the vegetation. Notable exceptions to 1981), with the carpets and mud-bottoms this are the pioneering studies of Osvald occupying the wettest, most frequently (1928, 1955, 1970) on the North American flooded sites and the forests on the well peatland vegetation, which included flor dra i ned peat. The water-table depth i stic details on a number of bogs in the controls the distribution of trees in Northeast, and the work by Danman (1977). directly by its effect on nutrient supply. The latter dealt, however, only with the Nutrient uptake is improved on better vegetation of the ombrogenous bogs of dra i ned peat by increased decay and northeastern Maine. A few recent studies greater rooting depth. by Worley (1981) and Davis et al. (1983) provided a classification for the peatland vegetation of Maine, but their units are On minerotrophic peatlands, the rela defined too broadly to reflect the floris tionship between the physiognomy of the tic differences with respect to hydrology, vegetation and water level is much more water chemistry, and geographical 1oca complex, because several tree species can ti on. grow on permanently inundated habitats if 34 nutrfe~t supply 1s adequ&t~. Only exces affects especially vegetation types with a sive water level fluctuations may elimi large geographical range crossing major nate them here. vegetation zones (Figures 2 and 3). The floristic composition of the major These geographic changes could not be peat bog colllllunity types of the region adequately expressed in tabular form with will be described within the framework of out describing each of the habitats sepa the major physiognomic vegetation units. rately for each vegetation zone. This This description will be limited mostly to approach would have resulted in an the genuine bog vegetation. The bo~ bor unwieldy number of vegetation types and der vegetation and other strongly m1nero would have confounded the discussion of trophic vegetation vary widely in f1oris the vegetation-habitat relationships. As tic composition depending on the mineral an alternative, peat bog plants showing a ogy of the surrounding parent materials. clear geographic pattern within the region Describing the floristic composition of are listed in Table 9. This table shows this vegetation is beyond the scope of the species that are present in certain this conmunity profile. However, some of parts of the region. these colllllunities will be described in a general way in discussing the pattern of 5.1.1. Forests vegetation types within the major bog landforms of the region. In addition, Forests occur extensively on peatlands Table 4 shows the effect of habitat but mostly on nutrient-enriched sites. changes on the dominant tree species in These forests may be geographically asso the bog border forests of each of the ciated with peat bogs, usually occupying three forest zones of the region. the bog border, but they are not part of the bog vegetation proper. The composi An overview of the floristic composi tion of these forests varies with seepage tion of the conmon plant co11111unity types flow and fertility of the surrounding of the bogs, and the differences among uplands. Floristic composition will not them, is given in Tables 5, 6, 7, and 8. be discussed here, but the major trends in These types are based on habitat-related the dominant tree species are shown in differences in species composition and on Table 4. In general, red maple (Acer rub data collected throughout the range of the rum) and Atlantic white cedar (Chaiilaecy types. There are clear phytogeographic pari s thyoi des) forests occupy the bog changes within this region that are also borders and dominate the forested swamps reflected in the bog vegetation. This of the Appalachian Oak Zone (Nichols 1915; Table 4. Major trends in the dominant tree species in peatland forests with respect to nutrient regime and geographical location. Eutrophic and mesotrophic Mesotrophic 01 igotrophic Zone seepage water stagnant water stagnant water Appa 1achi an oak ker rubrum Chamaecyparis thyoides Picea mariana Tsuga canadensis ACer rubrum Northern hardwoods ker rubrum ker rubrum Picea mariana TfiUJa occidentalis Thuja occidentalis Tsuga canadens1s Boreal and coastal Spruce-fir Picea mariana Picea mariana Picea mariana 1ffiTeS ba 1same a 35 Table 5. Floristic composition of the tall shrub thickets and black spruce boq forests. 2 4 5 COMMUNITY rREE LAYER Hdghi (ml 1CH6 Cover(%) At:a mbrnm (Red :\-lapie) ...... o-i ...... t ari;i; hmi.:uw (Lairctl) P1.cea nMmirw (H!ack Spruce) Prnus suobus (Whac Pi.nu;, 1'1gida (Pitch PineJ ~h;~,, h;:i/qmr."I ffbk-nn Firl :--.; SHRL:B LAYER (2 J Cover ((I'•)) 80- lUlJ t\0-lOO <~1( Vao;:1omw 1.:orymbo_1um (H1ghou~h l:Huebeiry) Rh()d{)(ieridmn 1-1scosu111 (S,~ar.np Honeys.u1.:klc1 RhoJodrndron 1wd1t1orum (Plirpk flon.:yH1c:kie1 L_;onrn itgw1nnt:1. (.Y1a!eoe!'fyJ Pyrus arbutifofla (Red Ch<:iket1erry; Clelh1a .1Jm!Olu1 (Sv>eet Pepperb Cover (%'1 Ch<1n1aedaphnc .:a/ycu/<.JI (iavfu~sacia bac,:a1a liayfu;,rncrn frondo.~n S \!acciwum angusutol1um J-!--- Vacciwum ox_> ·co..._·,·(h Droscra rowm.11lo/1i:1 -- Sarrnccnw purpur(a C:1u:x rrispama •,ctr !Jillmg!>ir Cvn 1nsperma ()<;mund;i 1,·uw:~1nomt•a Sm1lac1na udolia :"'< Cdf&.11. p (are~ cn1111a lolircula1a C:uex ,rnct,i 1Jr_,op1r:r1 .., llu:l7pit·t1.~ S)mplonupu.1 t11et1du.1 \..\.uodwardrn \i/f~!!.1mca (Jrt'.i n{lH:'I 36 Table 5. Concluded. COMMUNITY .\10S\ 1 A Yi.:R 60-80 8U-1GO SphagnHm magdlan1cum Sph fllllllll-111 Dominarll: ~U\CI over .+()Cro c-::r::~:-:r:-,.rn '.-,umt·tinw> domin \1tu).!raph1c<1! change\ n1 'pcuc<, corripo\1llon within a l)pt are indKated as foilu,~\: ~ -oc..:ur) ~·\)rnmonly rn this community type rn nonhern part {11 reg;on but r<11t' u1 ,1b.,1.:111 rn '>llUt:1cr11 p Bromley 1935). Northern white cedar type occurs also on genuinely ombrotrophic (Thuja occidentalis) and red maple domi sites such as the slopes of plateau bogs nate forested bog borders in the Northern and the centers of convex raised bogs Hardwood Zone, and black spruce (Picea (Da1TU11an 1977). This is an open-to-dense mariana) dominates those in the Boreal black spruce forest and the forest floor Zone. Closed black spruce forests occur is covered with a well-developed Sphagnum rarely in the peat bogs of the Appalachian carpet, dominated usually by~· magellani Oak Zone, but they become common north cum (Table 5). The density of the dWarf ward. shrub layer decreases with stand density. Ledum groenlandicum and Kalmia angustifo Two black spruce co1J111unity types, the Tlclare the dominant dwarf-shrubs in the Sphagnum magellanicum-black spruce forest north. The dwarf-shrub layer is impover and the Carex trisperma-black spruce for ished in the Appalachian Oak Zone. Cha est, are included in Table 5. The latter maedaphne calyculata is most common, -arld occurs on sites receiving telluric water occasional shrubs of Vaccinium coryllDosum from the surrounding uplands. It is a are present. common black spruce forest on peat depos its in northern New England. It is Carex trisperma-black spruce forest. included to emphasize the differences with This-is the common bog border forest of the Sphagnum magellanicum-black spruce the Boreal zone and adjacent parts of the forest. Northern Hardwood Zone. It is distin guished most easily by the abundance of Sphagnum magellanicum-black spruce Carex trisperma, the regular occurrence of forest. This community type is found on 1JSiTiliTlda c1nnamomea, and the well-developed oligotrophic peat throughout the region, S~agnum carpet (Table 5). Balsam fir although it is rare in the Appalachian Oak ( ies balsamea) is usually present in Zone. In northern Maine, this conmunity these forests. 37 Table 6. Floristic composition of the d'."Jarf-~hrub 2 3 4 5 Sphagnum rubellum- Chamaedaphne COMMUNITY SUBSTRATE SOUD FLOATJNC OR Ql:AK!NG SOU[) OMBROTROPHlC OLJGOTROPHlC TREE AND SHRUB LA YER Height (m) 6 8 l. 5 l. 5 Cover(%) HERB LAYER' Height (cm) 10-15 30-bU Cover {%) 30-8() 90-100 80-100 75-100 75-100 90-100 90-100 90-100 Chamaedaphne ca/yculaca Gaylussacfo bacca1a i-1--·----1~ ~~~!l~~~---1___ ., __ _ Kalm1a angvscifolia Kalm1a polifolia Andromed {Cominued) 38 Table 6. Concluded. COMMUNJTY 2 3 4 5 6 7 8 60-100 60- l.OO 90-100 80- l 00 90-~ 1 00 30-100 75-100 Spfwgnum 1 ulidfurn - ...... w.. --- /)ic:r ~ lddOllld rrllil.' ------! ("hulon111 ::(iJH.'',lrl\ ------... f'c>hl'tchum ;(flct:11n 1----1- \phti_unurn 1rnbnc.aum () frm<-tJlip(11fo Ct!VC(Ufl/{1) Odunto:.ch1.,rn;J ~pha~i,;w ("Jadu111a cn1.par:i ("/nJuua cr1'>1a:dla Cladunw 1-crucriiata ("JadOfll{/ lllll'l.:l/11 Claclonra )(/U.:lrlW.\um rz:v???';(.:(4 ~ - .... - .... - SphagnuH1 {11nh11arurn i----i·---i- - Splrngrwm cnH nilc Sph.:tgrJum pulchrur11 .\ph~igrium !lt:.\l.IO.\Uf/J , 1 J lli ldil, :.<.:., dl~U \\U'.J\.l} ~))t:<:lt.:', VTlll'> 1:1du 5.1. 2. Tall-Shrub Thickets blueberry thickets. It occurs mostly on peat soils with strong water-level fluctu Tall-shrub thickets dominated by high ations and occasionally on a quaking mat. bush blueberry (Vaccinium corymbosum) and It is flooded by weakly minerotrophic swamp azalea (Rhododendron v1scosum) are water but does not receive seepage water. common in the bogs of the Appalachian Oak Zone and extend into the southern part of The ground vegetation is poorly devel the Northern Hardwood Zone. Northward, oped and peat is exposed on much of the shrub thickets are usually dominated by surface. The influence of weakly minero Mountain-Holly (Nemopanthus mucronata) and trophi c water is best expressed in the black spruce. Floristically and ecologi composition of the moss layer by the pres cally, these northern shrub thickets dif ence of Spha2num fimbriatum, S. fallax, fer profoundly from the ericaceous south and Aul acomnium pa lustre ( lable-S). ern tall-shrub thickets. They lack the southern species (Table 9), and ericaceous Cinnamon fern-highbush blueberry shrubs form a dwarf-shrub rather than a thicl 39 r,.~·~-~1 . ... J ...... J Table 7. Floristic composition of ombrotrophic and ...,..,,,,., ...... ,.,, ..... v ..... oligotrophic vegetation dominated by graminoids.8 COMMUNITY 2 3 \-10SS LAYER v, c: ::i Splwg1mm magdlanicum c: (j.) c: ~ "'"' e- Sphagnum rubdlum ... ·o ::: Sph<1gnum ! tis~·wn :\ o:l 0 ~ <;; 0 VJ 'iphagnum frilla:t. t: 0. I ::i"' Sphagnum papillo,~um >. e Sph,1gnum pulchrum 0 ::i "' "'.... v 2 Sphagnum (/e.\uo:;mn t:: ·- a OJ) 0.. Sphagnum pulchnn1ma S ~ -: .;inhwwum ccmrak ---1-- COMMUNITY 0 f.l:.l er; Splwgnum cuspulatum OM BRO· Sph (ContrnuedJ of the three tall-shrub thickets. 40 able Mud·bottom and carpet ve ly. The first two occupy communities. 1-defined sites in the ombro trophic parts of bogs, whereas the Chamae daphne calyculata-dominated dwarf-shrub heath occurs on various oligotrophic and ombrotrophic sites. This community type is very heterogeneous, both floristically and ecologically. It has been divided into five floristically distinct corrmunity types. Three of these develop on a float ing or quaking mat and are never flooded; the floristic differences between these C(ne1· (lf'o J 30-80 65-80 types are caused by differences in nut Height (<.:m) 10 50 rient supply. The other two Chamaedaphne Rh.indw1.pu1a afbo1 dominated types are flooded regularly. lu11cula11a cornura \1r1' mon1.:1na '.'\. [)ru,c1;1 1mcrmed111 In regions with severe winters, erica ('h 1 ' f fu<, rc·prt''-C/11~ the '>flCVH'I 1·ompo<.!l10n on l1mbro1roph1c and (l/1gouopfm >1in On <.Jin 1111/"i Empetrum nigrum-Sphagnum fuscum commu l/ronµt'r mmciaf V)lf--w:acr m17ut·ncc. rhc moss /;Jyc'/" I) dommared b,1 Spha,grwm talhn, <., pu/cflrum. Dr-"· ma;tL\, and the lo!ltmrng \a-,cu!ar plant<. are U)ual!y pre)tnl 111 ihc :\01the1n Hard\1ood Lone nity (Figure 26). This community is and nonh\\ar 41 -- Table 9. Species showing clear regional differences in abu~d3"Ge region. The southern species are restricted to the southern half of the except as shown. Habitat preference Southern species Northern species Wide ecological Rhododendron canadense amplitude, occur in Ledum 9roenlandi~ many types ~gale !$._tlmiLarix laricina Pinus rigida Thuja occidentalis Chamaecyparis thyoides Al nus rugosa Rhus vernix Al nus crispa**• d ciethra alnifol ia "5iITT1Ta natrTfo 1 i a Alnus serrulata Carex pauperculaa WOOdWardia virginica Linnaea borea1is Symplocarpus foetidus* CiTTltOiiia borealis Pyrus arbutifolia Gau 1t_~.ciA. hi~HU du@ Carex howei Sj)hagnum pulchricomac Lake border of Decodon verticillatus Chamaedaphne mat and Peltandra virginica Carex rostrata fen Cephalanthus occidental is Mud-bottoms and lSY.!:12. caroliniana Xyri s montana shallow pools Sphagnum torreyanum* Carex limosa MenYantheStrifol iata Sphagnum majusa Sphagnum jenseniid ~_llagnum tene 11 um d aThe following symbols are used to indicate additional geographic trends: * Southern species that also occurs in coastal areas farther north; ** = Northern species abundant only along the east coast of northern Maine. bThis includes: C. ranliferina, C. mitis, C. arbuscula, C. alpestris and C. terrae~novae.-All o these reTndeer mosses show the same pattern, with the last primarily occurring in the coastal areas of northern Maine. cThis is S. recurvum P. Beauv. The latter name has not been used here to avoid confuSTOnSTnce it is also used as a collective name to include ~· angustifolium, S. fallax and S. flexuosum. dSpecies occurring only in northern New England. Others in the column occur throughout the region but are much less common southward. 42 \I )1 ,,[ ~\'·. ~...f\ ~ ·'.·r~ ~ )j . ~ !' V':Vrf J/ f:_ f.~ii I II I \')I \~ \\ ~ Figure 25. Ericaceous dwarf-shrubs common in peat bogs of the Northeast: (al Kalmia polifolia, (bl Kalmia angustifolia, (cl Ledum groenlandicum, (di Chamaedaphne calyculata. (el Andromeda glaucophylla, (fl Rhododendron canadense. (g) Gaylussacia baccata, (hi Gaylussacia dumosa, (i) Vaccinium angustifolium, (jl Vaccinium macrocarpon. (kl Vaccinium oxycoccos. 43 Figure 26. Empetrum nigrum-Sphagnum fuscum community (Quoddy Neck, ME). Note the low height of dwarf-shrubs, such as Kalmia angustifolia, the common occurrence of Scirpus cespitosus and the abundance of lichens. further details on the floristic composi quently burnt until about 20 years ago. tion. Depending on fire hi story, the Sphagnum cover varies greatly. Osvald's (1970) Sphagnum fuscum-Kalmia community (Fig naked Kal_111i~ ~_Q_g~2_!:ifo_}J~_ association ure 27). This is the most common dwarf probably refers to such burnt sites. shrub community in the northern part of the region. It occurs on relatively well drained peat and often covers the major part of a bog. Near the coast, this com Sphagnum fuscum-Gaylussacia baccata munity is restricted to small bogs and community (Figure 28). This community sheltered parts of large bogs. Kalmia occupies the driest parts of the bogs in angustifolia forms a 30-40 cm high dwarf the northern part of the region and covers shrub layer that determines the physiog large areas in the center of convex domed nomy of the vegetation and most easily bogs (Damman 1977). It is absent in the separates it from other dwarf-shrub vege bogs of the coastal zone of the Bay of tation on ombrotrophic peat. In the Fundy. Gaylussacia baccata dominates the coastal areas of Maine, Empetrum nigrum, dwarf-shrub layer and 1s usually 50-60 cm Ru bus chamaemorus, Sphag~i ni5rTcatum, high. Kalmia angustifolia is abundant a:na-s. · tlav1comans are found regularly in throughou_t_. -lh1s- community shares with this-community type. the two previous types many species of nutrient-poor sites (Table 6). Fires Fire destroys the Sphagnum carpet and reduce the ~hagnum cover and increase the increases the Cladonia cover, especially Cladonia cover as oescribed for the Sphag that of Cladon a c spata (Damman 1977). num fuscum-Kalmia type. Trees are often Many bogs--rnri"ortheastern - Maine were fre- sparse--rn-this type because of fire. 44 Figure 27. Sphagnum fuscum-Kalmia angustifolia community on the slope of a plateau bog (Jonesport Bog, ME). Kalmia angustifolia is the dominant dwarf-shrub. Figure 28. Sphagnum fuscum-Gaylussacia baccata community in the center of a convex raised bog (Meddybemps Heath, ME). Fires have removed most of the trees in this part of the bog, but more trees survived the fires near the pools in the bog center (center background). 45 Sphagnum rubellum-Chamaedaphne commu The nity (Figure 29). This community repre other sents the most nutrient-poor vegetation on bogs is floating or quaking bog mats throughout lum, or occasional the region. Chamaedaphne calyculata and tfie moss carpet. Sphagnum rubellum are always the dom1nant ni ty lacks many more nu tri species; the abundance of many bog species species, especially in the interior of the with northern or southern affinities var bog mat vegetation (Table 6). An impover ies with geographic location (Tables 6 and ished form of this community type, in 9). In contrast to the three previous which Chamaedaphne is only 10 cm high, types, lichens are never abundant here. occurs in filled-ln pools of ombrotrophic bogs (Damman 1977). Toward the lake edge, the mat vegeta tion is enriched by lake water, especially Sphagnum fallax-Chamaedaphne community on the windward side. This results in the (Figure 31). This community occurs on presence of many species that are other floating and quaking bog mats influenced wise absent (Table 6). Low trees and by more nutrient-rich water than the shrubs are conmen in this zone (Fig. 30). S~hagnum rubellum-Chamaedaphne community. The zone shows clear geographical changes I is found throughout the region but is in its floristic composition, since many the most conmen bog mat vegetation in the species show southern affinities (Table southern part of the region. The moss 9), e.g., Peltandra virfinica, Decodon carpet is dominated by either Sphagnum verticillatus, and Cepha anthus occiden fallax or Sphagnum papillosum. Yacc1n1um tal is. macrocarpon is usually present, and other Figure 29. Sphagnum rubeflum-Chamaedaphne ca/yculata community on quaking bog mat (Beckley Bog, CT}. Chamaedaphne is the dominant dwarf-shrub species; both Ledum groenlandicum and Ka/mia polifo/ia are also visible on photograph. 46 Figure 30. Margin of bog mat enriched by lake water. Carex lasiocarpa and many other more nutrient demanding species are restricted to this part of the mat, and larch and black spruce occur as low trees in this zone (Pond Hill Pond Bog, CT). Figure 31. Sphagnum fa/lax-Chamaedaphne calyculata community. The arching shoots of water-willow (Decodon verticilfatus) are scattered throughout the mat, and buttonbush (Cephalanthus occidentalis) can be seen in foreground (Cranberry Pond Bog, PA). 47 more nutrient-demanding species such as 5.1.4. Dul ichium arundinaceum occur frequently; other flori stic differences are shown in The co1m1unities included here are dom Table 6. The community shows obvious geo inated by sedges and have a water table graphic differences. Decodon verticilla rising above the surface during wet peri - tus, Sphagnum f1I avi comans, and ~· pulchri - ods. Floristica1ly and ecol ly, how coma can be common in the southern bogs, ever, they form a heterogeneous group. ana- Eriophorum angustifolium is often abundant in the northern bogs (Tables 6 Carex rostrata comrnuni~y (Figure 32). and 9). This conmun1ty is common on wet, nutrient poor sites that receive seepage from the Sphagnum centrale-Chamaedaphne commu surrounding uplands. The peat is often nity. This community, flooded regularly less than 1 m deep. Although it is influ oynutrient-poor water, occurs in basins enced by nutrient-poor minerotrophic with large water-level fluctuations and water, it represents the most nutrient more rarely along brooks. It is most com rich of the three communities described mon in the southern part of the region, here. probably because of large evapotranspira tion losses and, consequently, larger The Carex rostrata community is flor water-level fluctuations. The community istically----aiia physiognomically clearly is most easily recognized by the irregular distinguished from the other co!11Tlunities hummocky surface, the evidence of flood described here. Carex rostrata, 60-70 cm ing, and its low species diversity. Cha high, dominates t~egetat1on, Chamae maeda~hne calyculata completely dominates daphne calyculata occurs with variable the warf-shrub layer. Floristically, cover, and a variety of shrubs {Table 7) this is the poorest of the Chamaedaphne are scattered throughout. The moss carpet dwarf-shrub bogs. The cover of the moss is mostly well developed and dominated by layer varies and is frequently patchy. Sphagnum papillosum or~· fall ax. Osmunda Sphagnum fallax is usually most abundant; cinnamomea, Dryopteris thelypteris, Calam S. centrale and S. fimbriatum are always agrost1s canadensis, Polytrichum coiiiim:iiie, present (table 6)-;- Carex str1cta is often Sphagnum f1mbr1atum, and S. centrale are present on sites w~relatively smal 1 usually present (Table 7). water-level fluctuations. Low bushes of Spiraea spp., Vaccinium coryrnbosum, and Extremely poor fen community (Figure Rhododendron viscosum are conspicuous in 33). This typical lagg vegetation of the the south. northern half of the region separates the bog vegetation from the surrounding min eral soil or from the shrub-covered miner Rhododendron canadense-Chamaedaphne otrophic bog-border vegetation. It also community. This community occurs in the occurs alone on comparable habitats. northern parts of the region where it occupies bog sites flooded by very weakly Several grass-like species, e.g., minerotrophic water or by drainage water Carex exilis, Scirpus cespitosus, R~yn from ombrotrophic bogs. The community is ~ora alba, Eriophorum angustifol1um, found on the lower slope of raised bogs and . v-:rrg:lnicum, are abundant in the flooded only in the spring by meltwater herblayer; nevertheless, the Sphagnum {Da111T1an 1977), in water tracks of ombro carpet determines the appearance of this trophic bogs, and along brooks draining community (Table 7). Four Sphagnum spec ombrotrophic bogs. ies,~· fallax, ~· papillosum, ~· rubel lum, and S. ~ulchrum, are abundant and make up most o the moss carpet. Several The most conspicuous difference from other species, e.g., Aster nemoralis and the other Chamaeda~hne dwarf-shrub bogs is Smilacina trifolia, clearly distinguish the abundance of riophorum angustifolium this community.-- and Rhododendron canadense. It has a well-developed moss carpet dominated by Spha~num-Sci rpus cespitosus community Sphagnum rubellum or S. magellanicum (Figure 4). This ombrotrophic lawn com (Table 6). - munity occupies most of the center of the 48 Figure 32. Carex rostrata community on shallow minerotrophic peat with scattered larch, red maple, and highbush blueberry. Cinnamon fern IOsmunda cinnamomea) clumps are visible at left. Leather leaf (Chamaedaphne calyculata) is common but mostly hidden by the sedges {Tobyhanna, PA). Figure 33. Extremely poor fen community covers an extensive area in this soligenous fen in northern Maine and occupies most of the foreground in the photograph. Eriophorum angustifolium, Carex o/igosperma, and C. exilis are the most abundant sedges in this fen (Attean Lake, ME). 49 Figure 34. Sphagnum-Scirpus cespitosus community in the center of a plateau bog (Jonesport Bog, ME). Note the abundance of Scirpus cespitosus and lichens, mostly reindeer mosses. plateau bogs along the Bay of Fundy (Dam bogs. Nowhere in the region do they cover man 1977). It is widespread further large areas, but they form a conspicuous north, but restricted to this area within part of the bog vegetation. Two communi the Northeastern United States. ties are described here. The abundance of Scirpus cespitosus Rhynchospora alba mud-bottom community and Cladonia species (often over 25%) dis (Figure 35). This is the norma 1 mud bot tinguishes this community, which repre tom vegetation distributed throughout the sents a dry variant of the lawn community region. This community can be dominated occupying the plateau bogs of Nova Scotia by either Cladopodiella fluitans, a liver (Danman 1977). The species characterizing wort, or by Sphagnum cusp1datum (Danman the oceanic plateau bogs appear in Maine 1977). Utricularia cornuta is always only in a few bogs in extreme coastal abundant, but the small leaves are hidden 1ocations ( Damrnan and Dowhan 1981). Tab 1e in the moss carpet, and this species is 7 shows other floristic criteria separat only conspicuous when it is flowering. ing this from the other communities. Cladopodiella fluitans dominates if 5.1.5. Carpet and Mud-Bottom Vegetation the community occupies shallow peaty depressions in the bog that dry up regu This includes communities of wet larly; Sphagnum cuspidatum if it is situ depressions consisting either of a very ated along the margin of a pool or if the loose Sphagnum carpet or covered with liv Sphagnum mat fluctuates with the water erworts and resembling surfaces with table. Table 8 shows the composition of exposed peat. Carpet and mud-bottom vege this community if it occurs within the tation occur on floating and quaking mats Sphagnum rubellum-Chamaedaphne community as well as solid peat in ombrotrophic of nutrient-poor floating bog mats. 50 Figure 35. Rhynchospora alba mud--bottom community surrounded by dwarf-shrub vegetation (Meddybemps Heath, ME). The liverwort Cladopodiel/a fluitans covers most of the dark area in the right center. The light area surrounding this is dominated by Rhynchospora alba and Sphagnum cuspidatum. Utriculara cornuta is common in both zones but not visible in photographs. A Sphagnum rubellum carpet (dark tone) with some leather leaf (Chamaedaphne calyculata) separates the mud bottom vegetation from the dwarf shrub bog. Northward, Sphagnum tenellum, S. majus, thin. Besides Carex rostrata, several and Xyri s montana appear,- ana several other nutrient-demanaing species can be species-oecome more abundant (Table 9). present, e.g., Typha latifolia and Phrag On ombrotrophic bogs, the floristic compo mites; the moss carpet has a different sition of this community is similar (Dam composition than in typical mud-bottoms man 1977). In fens within the Northern (Table 8). Hardwood Zone and north, the moss layer is usually dominated by Sphagnum pulchrum, S. 5.2 VEGETATION PATTERNS IN PEAT BOGS papillosum, S. fallax, or S. maJUS-,- and the -following vascular plants are usually 5.2.1. !actors Controlling the Vegetation present: Eriophorum anfustifol ium, Carex Pattern limosa, Scheuchzeria ~ust~is, and Men yanthes trifoliata. Peat bog vegetation frequently shows a distinct zonation, which is often consid Carex rostrata mud - bottom community ered a result of hydrarch succession, and (Figure 36). Locally Carex rostrata can elaborate successional diagrams have been dominate these mud-bottomsites. This developed for plant communities in bogs happens most frequently on floating mats (e.g., Dansereau and Segadas-Vianna 1952). in the southern bogs where nutrient-rich Succession affects the structure and flor lake water or telluric water reaches the istic composition in peat bog-lake systems bog surface. Such sites represent fen with open water (Swan and Gill 1970). windows in the bog mat, and they deve 1op However, even in these systems much of the usually on places where the bog mat is vegetation zonation observed is related to 51 Figure 36. A fen window in Sphagnum rube/lum-Chamaedaphne vegetation on a quaking bog mat. The sedge Carex rostrata dominates the physiognomy of the mud-bottom vegetation in the fen window (Beckley Bog, CT). the chemistry and flow of water in the The vegetation patterns in bogs can be bog. In bogs formed by swamping or palu explained largely by water chemistry and dification (Granlund 1932; Gore 1983) of water movement through the bog, and suc dry land rather than filling-in of a lake, cession is less important in shaping the the vegetation pattern is completely con vegetation than is often assumed. The trolled by the hydrology of the bog and relation between water chemistry and flor the source of the water (Sjors 1948; Mal istic composition of the bog vegetation mer 1962a; Da11111an and Dowhan 1981). has been the subject of many studies (Sjors 1950; Schwintzer and Tomberlin Stratigraphic studies clearly show 1982; Vitt and Bayley 1984). The pro that succession has been important in con cesses affecting water flow in peat are trolling the vegetation pattern. However, reasonably well understood; nevertheless, at present many peatlands are in equilib flow through peat bogs is poorly docu rium with the climate, and by and large mented and 1 imited mostly to ·input-output the vegetation zonation remains stable, studies (Verry 1975; Hemond 1980). The unless the hydrology is changed. This large local variations in seepage along applies to most of the soligenous and omb the bog border, combined with the vertical rogenous bogs in the northern part of the differences in hydraulic conductivity of region but, apparently, is also true for the peat, hamper quantification of water many topogenous bogs. Once a 1ake is flow. Published data on flow patterns filled in, peat accumulation will not within peat bogs are not available for the raise the surface much above the water Northeast. However, this flow pattern table, unless the climatic conditions determines the changes in water quality allow ombrogenous bog formation. Wetness and vegetation within a peatland and combined with nutrient deficiency can keep causes the differences in vegetation pat forests from occupying these sites. terns among peatlands. 52 vanov (l~b/, lYHl) and I i i ssed va ous flow in t ¥ tlands, Ivanov's elaborate classifica- on is too form the basis for a discussion on patterns. Also it does not include all conditions found in the -lake systems of our region. Nevertheless, his ideas and those of Ingram influenced the following discus sion. 5.2.Z. ~egetation Patterns in Relation to i Water Flow and Habitat r The nature of the bog water and its flow pattern will be described for a few of the major peat bog landforms of the region. This information will then be related to the vegetation patterns in these peatlands. This section clarifies the essential features of the various bog landforms, highlights the differences I I among them, and provides an understanding t t of the causes of deviations from the pat terns discussed here. Peat bof-lake systems. These systems are all inf uencea by minerotrophic water, but its effect on the surface vegetation changes during their development. The successional changes in water movement are illustrated in Figure 37. Minerotrophic I inputs to the bog come from the lake water and from telluric water seeping in at the i t i i bog border. The bogs develop in oligo MSWL MSWL trophic lakes and, therefore, the seepage water is more fertile. Its chemical com ----. ·- position depends mostly on the nature of d ; ~.: :.:·> -- ' .. . •,.·.·.· the surrounding deposits and the length of .. : :· .. the slopes. The amount of seepage is largest in landscapes with compacted till or bedrock near the soil surface, and it shows strong, seasonal variations. In early spring, surface runoff will add to t t = PR ECIPJT ATION the mineral -soil water input, which is -- = WATER FLOW mainly rainwater and melt water that have MINERAL SOIL MSWL = MINERAL SOIL barely contacted the mineral soil. Conse l:>:U\'.\;I = WATER WATER LIMIT quently, the water is very weakly minero INFLUENCE trophic. Figure 37. Changes in water flow and nutrient input The bog mat floats, and this prevents to the bog surface during hydrarch succession shown flooding by the lake. The water table is in cross section and plan view. Diagrams a, b, and c almost stable, usually at 10-20 cm below show bog development typical for most of the region; the Sphagnum surface. lake water is drawn diagram d applies only to the three northern peatland to the surface by evaporation. At the zones (Figure 3). Seepage input is rarely uniform along margin of the mat, lake water can also be the bog border. The dense clusters of dots in the plan thrown on the surface by wave action. views are fen windows where more nutrient-rich This marginal zone becomes more narrow as water reaches the bog surface. 53 the bog mat grows, and the lake becomes water levels fluctuate with n smaller and wave action diminishes. lni- Presumably, this oecomt><:; ally, the pond-border bog is influenced as the bog mat thickens. ng the ear- by minerotrophic water in several ways. lier stages of mat deve1 one can However, when the mat becomes more exten observe a similar increase in water-level sive, three zones are recognizable (Figure fluctuation from the to min- 37): a border zone with seepage input- eral soil contact as becomes its effect decreases with distance from grounded. In these filled-in lakes, the the border; a zone influenced by lake Chamaedaphne mat covers the en ti re bog water through the bog mat -- its effect center, but Decodon verti c i 11 often decreases with distance from the lake persists in some . 0 oor1y edge; and a zone a1 ong the edge of the mat growing black spruce, red maple, white enriched directly by lake water. pine, larch, and pitch pine (Pinus rigida) trees are scattered on the ~aedaphne The associated vegetation pattern is mat. shown in Figure 38. The diagram for the Appalachian Oak Zone and the southern part Major changes occur northward in the of the Northern Hardwood Zone shows the plant-community pattern of these bogs. pattern most commonly found in the south First northern white cedar (Thuja occiden ern part of the region. In the southern talis) replaces the red maple-anQ Atlantic r::oasta1 areas, the Atlantic white cedar Wfffte cedar as the bog-border tree. (Chamaecyparis thyoides) can replace llllCh Finally, black spruce replaces northern of the Osmunaa-highbush blueberry thicket. white cedar (Figure 38). The Nemopanthus In this case, the cover of Vaccinium cor black spruce community forms the tran ymbosum and Rhododendron viscosum is nuch sition from the open Chamaedaphne mat to lower. Depending on the water chemistry, the spruce forest, and the Decodon zone is the bog mat can be either a Sphagnum absent, so Chamaedaphne becomes the prin rubellum-Chamaedaphne community (Figure cipal species extending the bog mat (Swan 38) or the slightly more nutrient-demand and Gill 1970). ing Sphafinum fallax-Chamaedaphne commu nity. Te occurrence of a Decodon verti cillatus zone at the edge of the mat"Ts In the initial stages of lake-fill characteristic for the southern bogs; it succession, the process is controlled plays a major role in extending the bog mainly by conditions in the lake and sur mat into the lake (Nichols 1915). Mud rounding uplands. Initially, climate bottoms occupy the low parts of the Cha- affects succession only indirectly. How maedaphne mat. - ever, climatic conditions become progres sively more important as the mat develops, The influence of the lake water is resulting in geographical differences weakest on the hummocks. The bog mat var within the bogs of the Northeast. The ies also in thickness, and the lake water relation between precipitation and evapo influence is stronger in some depressions transpiration during the vegetative season than in others. The Carex rostrata mud is most important, since these factors bottom col1111Unity occupTes---thin parts of control the upward and downward flow of the mat (Figure 38) or other sites that water in the surface peat. Increased pre contact more nutrient-rich water (fen win cipitation or lower evapotranspiration dows). When the bog mat has completely will make the Sphathum carpet less depen covered the lake, the entire bog center dent on water in e capillary zone above becomes nutrient-poor, although more nut the lake-water level. Within the North rient-rich depressions persist (Figure east, this dependence decreases roughly 37). Such bogs remain oligotrophic, with altitude and from south to north, although the surface peat of humnocks and until true oni:>rogenous bog development raised parts can become locally ont>ro becomes possible in the northern half of trophic. At this stage, water with sus Maine. pended organic matter is still present under the mat, and the bog mat rises and Moat bogs occur mostly in kettle holes falls with the bog-water level. However, in pitted outwash or kame deposits. They the mat has lost some flexibility and appear to be restricted to basins with 54 APPA.LACHIAN OAK AND SOUTHERN PART NORTHERN HARDWOOD ZONE OSfliUNUA SPHAGNUM HUGLL L.UM CHAMA!: DAPHNE SPllAGNUM RUE3ELLUM - CHAMAEDAPHNE AND MUD-BOTTOMS CAREX fRISPfRMA - BOREAL ZONE BALSAM FIR CAREX TRISPERMA BLACK SPF1UCE SPHAGNUM RUBELLUM CHAMAEDAPllNE--1·· AND MUD-BOTTOMS ·--·-··-··------~ /'-\# ''°'; .A Figure 38. Vegetation pattern of peat bog-lake systems in southern and northern part of region shown in cross section and plan view. Hemlock can also be common in the borders of bogs of the Appalachian-Oak and Northern Hardwood Zone (Table 4). strong water-level fluctuations. Refer bogs to a greater depth than in the ence to these bogs in the literature are border of bogs with a more stable water few (Nichols 1915; Rigg 1940; Osvald 1970; table. Buell and Buell 1975), and their develop ment is poorly understood. Presumably, In lake-fill bogs, the bog water the moat develops because during dry peri becomes gradually more nutrient-poor with ods peat decays in the border of moat distance from the border. The inflow from 55 the upland areas varies, and this causes surrounds the atn. local fertility differences in the bog It has a poorly but- border. In contrast, in the moat of the ton bush ( Cepha 1 s occ i usu- moat bogs the water chemistry is fairly a 11 y dominates a zone uniform, and the bog becomes more Glyceria canadensis and nutrient-poor from moat to bog center. a re usually present. dominate a zone along These moat bogs occur only in the floating mat. The southern part of the region, and there floating mat is the fore the vegetation does not show the maedaphne cofll!lunity geographical changes discussed above for sum often equally or the other peat bog-lake systems. The veg frnax. The grounded center ·1s occupied etation pattern of a moat bog is illus by the highbush blueberry community and trated in Figure 39. The moat completely either the Sphagnum fallax-Chamaedaphne or VEGETATION PATTERN CHANGES IN WATER CHEMISTRY HIGHBUSH BLUEBERRY CAREX CANESCENS OAK FOREST CEPHALANTHUS Figure 39. Vegetation pattern and changes in water chemistry in moat bogs. The density of stippling indicates degree of mineral-soil water influence. The nutrient regime in the moat is uniform, but the surface peat becomes more nutrient-poor from the edge of the bog mat to the bog center. 56 If summer flooding is common, this zone is occupied by a Sphagnum centrale-Chamae daphne community--wlffi-S. as--t'ne ma:ror--species in the moss carpet. I.,, 1 The summer water s is maintained by Oligotrophic peatlands outside lake streams or lakes. limnogenous peat basins. These ml"nerotrophic peatlands are s occur mostly in associa on with influ-enced by oligotrophic water. They ands and this influences have a solid, not quaking, bog surface hydrology. Water movement is toward the that can be flooded, but not by lake or stre~~ A~ i~v~ but the bogs are al50 brooi<. water. They have developed in vari flooded by·l~k~ or stream water during ous ways. The present con di ti ons at the high water (Figure 40). Therefore, the surface, rather than their origin, deter minerotrophic water affecting these bogs mine their hydrology and vegetation. is derived from two sources. In the nut rient-poor limnogenous bogs, the flooded zone is invariably more nutrient-rich than These bogs lack the large water reser the remainder of the bog. voir of the peat bog-lake systems; there fore they depend more directly on precipi The vegetation along the brook varies tation and mineral-soil water to maintain depending on the ionic composition of the their water levels. The mineral-soil brook water. It is mostly dominated by water can be stagnant (topogenous bogs) or either Carex lasiocarpa and Sphagnum fal flow laterally through the peat (solige l ax or 1Tthe'f5rool SPHAGNUM FU SCUM - KALMIA RHODODENDRON CANADENSE- MSWL CALAMAGROSTIS CANADENSIS I .. ·: .· ::: 7 .. :·.1 .....!..+ .. :.: I . . :;. __...I I .. . . I .. " Figure 40. Vegetation pattern and water flow in limnogenous bog system associated with an ombrotrophic bog (at left). Inside the mineral-soil water limit (MSWL), the Ca/amagrostis canadensis vegetation is regularly flooded by the brook, but the Rhododendron canadense-Chamaedaphne vegetation is flooded only during high spring water levels and receives ombrotrophic water the remainder of the year. 57 and water chemistry. The climatic condi centrale-Chamaectapnne comirruni tions, especially precipitation and evapo in openings in the th transpiration, influence both and are along the border. responsible for clear geographic trends in and Carex stricta these peatlands. row zone between this and the soil. Oligotrophic topogenous and soligenous peat bogs develop on nutrient-poor parent Basins with these large water-level materials and have either small watersheds fluctuations are uncorrmon northward. If or are affected by water diluted consider they occur beyond the northern limit of ab1y by rainwater, as in wet climates or dense Vaccinium corymbosum thickets, they large bogs. They can be associated with a are occupied bY a-l:namae 58 BASINS WITHOUT CQR_A}NED VALLEY WITH LIMITED SEEPAGE HIGHBUSH BLUEBERRY SPHAGNUM MAGELLANICUM - BLACK SPRUCE SWAMP GAYLUSSACIA- BLUEBERRY OAK FOREST ~ . . 0 ' 0 . " . 0 ' 0 • • 0 . . . I DRAINED VALLEY WITH OLIGOTROPHIC SEEPAGE I OSMUNDA- RE.D MAPLE SWAMP -0- Figure 41. Vegetation pattern and water flow in perched-water peatlands influenced by nutrient-poor minerotrophic water. The vegetation pattern is controlled by the flow rate and chemistry of the bog water. Hemlock can also be abundant in the border of these peatlands, especially those receiving seepage. See Table 4 for further details on bog border forests. 59 This type of highbush blueberry bog is illustrates the differences with the oli typical for the southern part of the gotrophic bogs that are the focal point of region because dense highbush blueberry this community profile. The hydrology of thickets do not develop northward. Also, ombrogenous bogs is discussed by Rycroft topographically similar habitats receive et al. (1975), Ivanov (1981), Ingram much more seepage during the su11111er far ( 1982, 1983) , and Damman ( 1986). The i r ther north and are fens or swamps. vegetation cover is described by Ganong (1897), Osvald (1970), Gauthier and (3) Bogs in drained basins with obvious Grandtner (1975), Damman (1977), and but very nutrient-~oor seepa{e input. Worley (1981). These bogs also rece ve their wa er supply as oligotrophic seepage water and precipi tation. However, here seepage water is 5.3 GEOGRAPHICAL CHANGES IN supplied throughout most of the vegetative HYDROLOGY AND VEGETATION season, regulating water levels so that they fluctuate within narrower limits than Geographical differences in the in the previous two situations. In addi hydrology of peatlands result from changes tion, the more continuous flow is clearly in the surplus of precipitation over eva reflected in the vegetation, with nut potranspirati on. In peat above a water rient-demanding plants in areas with table, upward movement of capillary water higher flow rates. Differences in nut and percolation of rainwater are control rient inputs are often not expressed in led by these processes when the bog is not the ionic composition of the bog water frozen. If the moisture surplus except outside the vegetative season. At increases, the bog surface will become that time, K concentrations reflect input more dependent on precipitation and more differences most clearly (Malmer 1962b; impoverished in nutrients. By itself, Da11111a n 1986) . this process will not lead to ombrogenous bog development but, at most, to local In the southern part of the region, ombrotrophy of the highest parts of the evapotranspiration losses are so high that bog surface. Complete ombrotrophy rarely this type of sol igenous mi re can rarely occurs on the hummocks of topogenous and develop. Conditions most closely resem soligenous mires, because vascular plant bling it in the Appalachian Oak Zone can roots reach into the minerotrophic peat develop on gentle lower slopes on nut and enrich the surface with leachates and rient-poor parent materials. If the sites detritus. remain moist during the surnner and the seepage water is nutrient deficient, the Ombrogenous-bog development depends on Carex rostrata conmunity will occupy such the rise of the bog surface beyond the sites (Figure 41). Larch and red maple influence of minerotrophic water. Since are scattered, and bushes of Vaccinium water flows primarily through the rela corymbosum and Rhododendron viscosum are tively undecomposed surface peat or over co111110n. The peat on these sites is usu the surface itself, minerotrophic water ally less than 1 m deep and well decom continues to affect the surface unless the posed. topography of the bog prevents this water movement. So, in topogenous peatlands Farther north, conditions for the water flow has to be reversed to initiate development of soligenous mires with a fen ombrotrophic bog development (Figure 37). vegetation become more favorable. This requires a rise of the bog center and the development of a perched water table Ombrogenous bogs. These are the genu in the peat to prevent mineral-soil water ine peat bogs of the cold temperate zone from reaching the center. with a topography controlled by differ ences in peat accumulation. They occur For the bog surface to rise in the only in the northern part of this region center, peat accumulation in this part of (Figure 2), and are often associated with the bog has to exceed that in the border. other peatlands. The vegetation patterns Peat acculllllation is the excess of produc of the three major types of raised bogs tion over decay, but it is due to slow (Figure 3) are shown in Figure 42. This decomposition rather than high production 60 BAY OF FUNDY PLATEAU BOG CAREX TRISPERMA - FOHf.. S I BLACK SPRUCL ex rnEMH v ------400 m · MSWL MSWL MOUNTAIN - HOU. Y - BL.AC/\ SYHUCE -·-----~~~ BLACK SPRUCE RHODODE NDl10N - C11AMAU)APHNE I! 00 rn ~ _ _.,I nHODOOl:NDRON - SPHAGNUM RUBE.LL.UM - CARE X TRISPEHMA - CHAMAEOAPHNE --- -- : 600 m •' MSWL MSWL Figure 42. Vegetation pattern in the three major raised bog types of northern New England. The mineral-soil water limit (MSWLI is indicated in all diagrams. The Sphagnum rubellum-Chamaedaphne community of these bogs is the poor variant with low Chamaedaphne typical for ombrotrophic bogs. 61 (Dan111an 1979b, 1986; C1ymo 1984). Decay of the ac below the water table is very slow, and a ti on. these decay rates differ 1ittl e between bog border and bog center. Therefore, we Local ombrotrophy, or near ombrotro are concerned mainly with the decay within phy, of hunmock surfaces in topogenous and the aerobic acrotelm. This depends on the solfgenous peatlands becomes progressively chemical composition of the organic matter conmon with increasing altitude and lati and the thickness of the acrotelm, in par tude. However, it is followed by ombroge ticular the length of time the organic nous bog development only in the northern matter remains within the acrotelm (Clymo part of the region. The processes leading 1984). Low nutrient concentrations in the to local ontirotrophy and to ont>rogenous bog center can decrease decay to the bog development are distinct. The differ extent that accultlllation exceeds that in ence between. them is most clearly the bog border in spite of the reduced expressed in the relationship between hum productivity (Dan111an 1979b, 1986). This mocks and hollows. As explained earlier, explains the elevation of the bog surface the initiation of ombrogenous bog develop but not that of the water table. The lat ment requires the rise of the bog surface ter is raised if a water mound, maintained so that a water mound can develop. When by precipitation, develops in the peat the water table in the bog center has been above the water table (Ivanov 1981; Ingram raised above that in the bog border, both 1982). This development requires a low humnocks and hollows will be ont>rotrophic. hydraulic conductivity of the peat in the In contrast, in topogenous and soligenous lower part of the acrotelm. Under such peatlands the hollows remain minero conditions, the water mound rises with the trophic, whereas the hunmocks may approach bog surface until the critical level (Iva oll'brotrophy. The sma 11 diameter of a hum nov 1981) is reached; this level depends mock in these minerotrophic peatlands on the climatic conditions and the hydrau- severely limits the maximum height of the 1ic conductivity of the peat above the water mound. Consequently, decay in the water level in the bog border. The devel hummock soon equals production and limits opment of a water mound reduces the depth further height growth above the mi nero trophi c peat surface. 62 CHAPTER 6. ANIMAL COMMUNITY COMPOSITION fU VERTEBRATES vegetation (Dodds 1974; Crossley and Gil bert 1983). Water and open-bog habitats Few studies have examined vertebrate represent only 1.0'.t and 1.5'.t, respec assemblages in peatlands. The most com tively, of the total home range of moose plete studies have been conducted in Min in northern Maine, but these habitats are nesota (Marshall and Buell 1955; Karns used significantly more than their rela 1979; Nordquist and Birney 1980; Warner tively small availability suggests. and Wells 1980), Michigan (Brewer 1967· Although areas of water and open bog were Ewert 1982), Canada (Buckner 1957a, 1966; used heavily during the surrmer, they were Erskin 1977; Muir 1977), and Scandinavia not used at all during the winter (Cross- (Jarvinen and Santnalisto 1976; Henttonen 1ey and Gilbert 1983). et al. 1977; Bostrom and Hansson 1981). The only extensive studies of vertebrate Formerly, the woodland caribou (Rangi assemblages in Northeastern peatlands are fer caribou) occurred throughout eastern those of Stockwell and Hunter (1985) and Canada and into northern Maine and extreme Brooks et a 1. ( 1987). northern New Hampshire and Vermont where smal 1 herds fed extensively in the bogs The vertebrate fauna of peatlands has and barrens (Allen 1972). Caribou were generally been considered rather depauper easily hunted and were eventually extir ate. There are no endemic species, and pated from the region. A few survived in few vertebrates use bogs as their primary the bogs of northern New Hampshire until habitat. However, the vertebrate species at least 1885 and in Maine near the St. diversity may actually be greater within Johns River until 1916 (Allen 1972). peatlands than in surrounding habitats because of the relatively great vegeta Bogs and other wetlands can be impor tional diversity. tant habitat components for black bears in the Northeast by providing thick escape 6 .1.1. Marrma ls cover (Eveland 1973; Kordek 1973; Landers et al. 1979) and an abundance of succulent Most large marrmal species in the food in the post-denning period (Landers Northeast move across peatlands, but few et al. 1979; Elowe 1984). The occurrence linger for long. Moose (Alces alces), of swamps is considered a key component of white-tailed deer (Odocoileus-vfrginfanUs) bear range in the Pocono region of north and black bear (Ursus americanus) use eastern Pennsylvania (Eveland 1973; Lind peatlands more t'fiai10ther large marrmal zey et al. 1976; Alt et al. 1980) and the species. The edges of bogs provide good most important factor determining the size browse, and deer use is so heavy in some of bear range in northwestern Massachu Maine bogs, that browse lines are apparent setts (Elowe 1984). Isolation of wetland (Worley 1981). Some forested pea tl ands pockets by residential development and provide deer with winter yarding areas other means reduces the value of suitable under dense stands of spruce or tamarack. bear habitat (Lindzey et al. 1976) and Moose are perhaps the most frequent and increases the vulnerability of bears by best-adapted large mammals exploit~ng attracting hunters (Kordek 1973; Landers Northeastern peatland habitats. Dur1~g et al. 1979). the surrmer moose extensively use aquatic habitats including lakes, ponds, stream~, Beaver (Castor canadensis) are fre and open bogs where they feed on aquatic quently founa · in peatlands with open 63 water, particularly those with flowing forests with relatively dry substrates, water (Johnson 1985), but their importance comprised lJJ~ of the captures in to beaver has not been investigated in the the shrub thicket and 15% in the for northeastern United States. In Minnesota, ested bog. The meadow vole (Microtus Rebertus (1986) found evidence of current pennsylvanicus), a species of fields and or previous beaver activity in 200 (42%) wet meadows, accounted for 10% of the cap of 481 bogs surveyed. This included 102 tures in laggs and 9% in streamside mead colony sites with over-wintering lodges at ows. The water shrew (Sorex palustris), the bog and 98 work areas with lodges in usually found along the edges of streams, adjacent ponds or streams. Beaver use of lakes, and beaver ponds, has frequently sedge-moss, tall-shrub, and wooded bog been associated with peatlands. It made cover types reflected their availability up 20% of the captures in laggs. Other in the landscape. However when inhabiting small mammal species included the smoky bogs with moats, beavers showed a signifi shrew (Sorex fumeus), pyglllY shrew (Sorex cant preference for sedge-moss and an hoyi), snort-ta1 led shrew (Blarina brev1- avoidance of tall-shrub cover types. In cauda), star-nosed mole (Condllura---cri bogs with flowage created by beaver dams, "St'a{a), southern bog lemm1ng Synaet~s beaver rarely used sedge-moss because this ~ri), deer mouse (Peromyscus ma01cua vegetation occurred in kettle hole bogs tus , and woodland jumping mouse (Napaeo that lacked sufficient ground water flow. t~pus insignis). The star-nosed mole is most aquatic of the North American Flooding by beavers can seriously dam moles and was only found on sites with age peatlands. Bogs with floating mats standing water (Stockwell and Hunter are least affected, because here rising 1985). In the Northeast, this mole is water levels flood only the grounded mat found in various wetland habitats, but near the upland margin of the bog. along the Atlantic Coastal Plain south to the Okefenokee Swamp, the southern edge of The diversity and density of small its range, it is mostly restricted to mammal populations in peatlands depends peatland habitats and has been found only 1 argely on the structural diversity of the in association with Sphagnum. peatland vegetation. Stockwell and Hunter (1985) captured 12 species of small mam In a one-year study of six peatlands mals in Maine peatlands. In their study in the Pocono region of Pennsylvania of seven vegetation types, they captured (Brooks et al. 1987) found a total of 21 as few as five species in 11K>ss-Chamae marrmal species, with white-tailed deer daphne and as many as 11 species in lagg being most frequently detected and pres and forested bog. The greatest number of ent on al 1 six sites. The three most small manmal species was in the two vege abundant small mammal species were the tation types with the greatest structural southern red-backed vole (78 at 5 sites), diversity and closest to upland habitats, white-footed mouse (Peroll\Yscus leucopus) whereas the smallest number was in vegeta (69 at 6 sites), and the masked shrew (68 tion types with the least structural div at 6 sites). Other documented small mam ersity and in the center of the peatlands, mal species included the meadow vole (8 at farthest from uplands. 3 sites), deer mouse (6 at 4 sites), short-tailed shrew (6 at 2 sites), meadow Using pitfall traps, Stockwell and jumping mouse (2 at 2 sites), and woodland Hunter (1985) found the masked shrew jumping mouse (1). (Sorex cinereus) to be the llK>St abundant species (67% of captured specimens) in The northern and southern bog lemmings every vegetation type except the shrub ( Synaptomys borea l is and ~. cooperi) thickets, where the meadow jumping mouse are perhaps more closely associated (Z~pus hudsonius) was most abundant. It with Sphagnum, although not necessarily ma e up 13% of all captures and was the peatlands, than any of the other second-most abundant small manmal species Northeastern mammals. Preble (1899) in streamside meadows, pools, shrub named the subspecies of northern heaths, and moss-Chamaeda~hne habitats. bog lemming found in the Northeast The southern red-backed vo e (Clethriono Syna~tomys borealis s~hagnicola because lllYS gapperi), most often found in spruce the ~pe specimen was rapped in a runway 64 st, bcrea1 b1rd species are an spec i - in peatlands of the tes in Spruce-Fir Zone of ine, i udi an ine, northern New Hampshire, northern on Mt. Katahdin, ine Vermont, and the Adirondack Mountains of and a spruce forest with a New York. South of the ranges of boreal ,....,____,,"'"=-··-mat near the base of Mt. species, peatlands are dominated by bird Clough and John J. species from surrounding habitats (Figure Albright, The Nature Conservancy, Maine 44). Birds that occupy wet meadows and Chapter; pers. comm.). In Eastern marshes are found in fens, and species Canada, the northern bog lemming primarily that inhabit shrubby forest openings also inhahits Snhaanum-1 ahradnr tPa-black inhabit shrub heaths. spruce bogs, but it is also found in deep, mossy, spruce woods, wet alpine meadows, Stockwell and Hunter (1985) reported and alpine tundra (Banfield 1974). 104 bird species in a 2-year study of Maine peatlands. Within an individual The southern bog lenming was initially peatland they found 29-69 species each considered a bog-dwelling species, but now year. Bird species richness in peatlands, it is known to occupy a wide variety of expressed as the number of species pres wet and upland habitats throughout its ent, was greater than that in surrounding range (Linzey 1983). However, in the habitats. They attributed this to the northeastern United States and southern variety of vegetation types occurring in Canada it is mostly associated with ~ relatively small areas in most peatlands. num bogs or heavily forested areas (Good For all peatlands, bird species richness win 1932; Hamilton 1941; Coventry 1942; is directly and independently correlated Connor 1953; Buckner 1957b; Manville with vegetation diversity and size of 1960). In Virginia, the southern bo~ lem peatland. Bird densities are also corre ming prefers habitats normally occupied by lated with peatland vegetation diversity. the meadow vole but, because of behavioral Bird densities are lower in peatlands dom dominance by the meadow vole, the southern inated by open patches than in peatlands bog lemning gains access only to the poor dominated by arboreal patches. Foliage est of these habitats during the low phase height diversity within a peatland is the of the vole population cycle (Linzey 1984; best indicator of bird species richness, Lfnzey and Cranford 1984). Habitats of bird density, and bird species composi marginal quality for meadow voles were tion. As foliage height diversity unavailable to southern bog lenmings even increases, bird species richness if minimal densities of voles were pres increases, bird density increases, and ent. In New Jersey, Connor (1959) found bird species composition changes. The that southern bog lemning numbers sur fewest bird species are found in fens and passed those of the meadow vole only in the most in wooded heaths. Most species ~hagnu~ bogs with shrub cover. Appar occur in several peatlands and in several ently, the same relationship exists types of vegetation (Figure 45). between the southern bog lemming and the meadow vole in Northeastern bogs as well. The conmon yellowthroat and Nashville warbler were present and abundant in all 6.1.2. Birds eight types of vegetation sampled (Stock well and Hunter 1985). Fifteen species Avian species with boreal affinities were corrmon or abundant in three or more are usually considered characteristic of vegetation types and 20 species in 1-2 Northeastern peatlands. Within the range vegetation types. Most species, including l i mi ts of bore al species, they dominate some frequently associated with bogs peatland avifaunas. In Maine, boreal bird (e.g., spruce grouse), were observed only species represented 58% of the avifauna of rarely. peatlands but only 33% of surrounding habitats (Brewer 1967). A number of Stockwell and Hunter (1985) found that boreal bird species reach the southern avian conmunities in bogs were distinctly edge of their ranges in either peatlands divided into two groups associated with or alpine habitats (Figure 43). Within arboreal and non-arboreal vegetation. 65 Brooks et ctl. (1037) f::::1r:d Spruce Grouse species in a one year Block - backed lands in the region Woodpecker nia. The 12 most included blue jay (90 at 6 sites), capped chickadee (76 at 6 sites), catbird (45 at 6 sites), cedar waxwing { at 6 sites), American crow (24 at 4 sites), red-winged blackbird (17 at 4 sites), rufus-sided towhee (15 at 4 sites), song sparrow (15 at 4 sites), northern flicker (14 at 5 sites), ruby crowned kinglet (13 at 6 sites), common yellowthroat (11 at 5 sites), and white throated sparrow (10 at 4 sites). Olive - sided,: In the Adirondack Mountains of New Flycatcher\ · '\ Rusty York Hardin (1975) recorded 30 bird spec )) ies on four peatland sites including two ;);(! conifer bogs (18 species), an ericaceous shrub bog (10 species), and a bog sedge meadow {14 species). Most abundant in each of these cover types were: the common yellowthroat (44) and song sparrow (50) in ~/) the two conifer bogs; bobolink (51) and c•J'/ song sparrow (10) in the ericaceous shrub --- ,: Palm Warbler Lincoln's Although Northeastern peatlands gener ally lack a distinctive avifauna, certain boreal species such as the spruce grouse have been considered representative. Most are boreal species that typically inhabit cool, wet, brushy openings, or edges in spruce-fir forests. Inc 1uded among these bird species are the spruce grouse, three toed and black-backed woodpeckers, olive sided and yellow-bellied flycatchers, gray jay, boreal chickadee, palm, Tennessee, Cape May, and bay-breasted warblers, Lin coln's sparrow, and rusty blackbird. Each Figure 43. Northeastern United States breeding of these species has a unique combination ranges of six boreal bird species characteristic of of habitat preferences, but they are all peatlands. regularly found in association with peat lands in northern New England and the Adi rondack Mountains of New York. Among the boreal species that charac Vegetation types within these categories terize northern New England bogs, the Lin shared many of the same bird species, and coln's sparrow and the palm warbler are the average degree of similarity between probably the two most restricted to this these two major groups was 0.63 (Figure habitat. The palm warbler breeds in open 46). They observed certain bird species in S2hagnum bogs of northern Maine, and the only one or two peatland types and other Lrncoln 1 s sparrow is found on the brushy species in several peatland types with edges of these bogs as far south as north similar vegetation characteristics. ern New Hampshire, Vermont and New York 66 L. GAST Ai_ SPHUC!:: FIR ZONE Spruce Grouse Black-backed Woodpecker Olive-sided Flycatcher Yellow-beilied Flycatcher Gra·y Jay Olive-sided Flycatcher Bornal Chickadee Yellow-bellied Flycatcher Black-throated Green Warbler Gray Jay White-winged Crossbill Palm Warbler Common Yellowthroa1 Rusty Blackbird Lincoln's Sparrow -:-re£ Swallow Palm Warbler Savannah Sparrow Black Duck Ring-necked Duck Black Spruce Sphagnum Tamarack Sundew Rhodora Bog laurel Labrador Tea Leatherleaf APPALACHIAN OAK ZONE Ruffed Grouse Downy Woodpecker Great Crested Flycatcher Eastern Wood Pewee Blue Jay Eastern Kingbird Black-capped Chickadee Gray Catbird Red-eyed Vireo Common Grackle American Redstart Yellow Warbler Common Yellowthroat Swamp Sparrow Rough-winged Swallow Song Sparrow Red-winged Blackbird Mallard Wood Duck Red Oak Red Maple Sedges Sphagnum Pitcher Plant Sundew Cranberry Highbush Blueberry Poison Sumac Leatherleaf White Azalea Figure 44. Comparison of bird distribution typical of a lake-border bog in the northern and southern part of the region. 67 ~ETATION TYf-'l (Brewster FB WH SH FE SM ST Spear 1976; Alder Flycatcher Kibbee 1985). ace their nests in a ll()Und cot Red-winged Blackbird tongrass (Knight 1904; s on Lincoln's Sparrow 1978). Palm Warbler Nashville Warbler 6.1.3. Amphibians and Reptil~~ Purple Finch Few amphibians or reptiles can be con sidered peatland species, but many North eastern species are found in peat1ands. Mognal1a Warbler The low pH of the water, the cool microha Black-ond-wh1te Warbler bitats, the saturated substrates, and the Yellow throat occasional flooding make bogs unsuitable habitats for some species. The constant moisture content of the Sphagnum moss Legend -1-4, -s-1s.-1:i-so.-s1-ss, substrate is particularly favorable for -89 126,->126 others. Some amphibians may be attracted to the moist microhabitats, but the bog FB FORESTED BOG FE = FEN WH =WOODED HEATH SM = STREAMSIDE MEADOW water may be too acid for breeding. OT SHRUB THICKET (MOUNTAIN HOLLY· In the New Jersey pine barrens, Gasner BLACK SPRUCE) and Black (1957) found that tadpoles of Figure 45. Distribution of ten bird species in Maine frog species occurring in acidic Sphagnum peatlands (redrawn after Stockwell and Hunter 1985). bogs were more tolerant of low pH than Densities are expressed as number of individuals/40 those of species occurring only in ponds ha based on 8 peatlands. Sample sizes for bog-border with higher pH. In general, boreal spec forest and wooded fen were too small to be included. ies are more acid tolerant and most can be found in or around bogs. The wood frog (Rana sylvatica) appears to be particu larly acid tolerant. Its eggs are able to survive and develop at pH 4.0 {Johnson 0.6 1985), although Karns (1979) never found wood frog larvae in water with a pH below w 0.63 :;) 5.0. Tolerance extremes and pH of great ...J o. 7 est hatching success for the spotted sala 0.71 ~ 0.72 mander (Ambystoma maculatum) under labora 0.78 a. 0.8 0.79. tory conditions were pH 6-10 and 7-9, <:( respectively (Pough and Wilson 1976). ...J er: Jefferson salamanders (Ambystoma jefferso w 0.9 0.88 nianum) tolerated more acidic conditions > 0.91 from pH 4 to 8, and achieved greatest 0 hatching success between pH 5 and 6. I . 0 ,___,___...___.____J,,_---L_ _J__-1.,__....__ Pough (1976) observed acid-tolerant egg LG WF F8 WH SH ST FE SM masses of spotted salamanders in New York ponds between pH 4.5 and 5.0, where most VEGETATION TYPE egg masses of this species had not sur LG ~ BOG-BORDER FOREST ST = SHRUB THICKET WF =WOODED FEN (MOUNTAIN HOLLY· vived. Cook (1983) found one pond in the FB = FORESTED BOG BLACK SPRUCE) Connecticut River Valley, Massachusetts, WH = WOODED HEATH FE = FEN where Jefferson and spotted salamanders SH = SHRUB HEATH SM = STREAMSIDE MEADOW were breeding successfully at pH 4.25. Figure 46. Dendrogram of overlap of vegetation types based on similarities of 1983 and 1984 bird species com In a study of eight vegetation types position on eight Maine peatlands (redrawn after in nine Maine bogs (Stockwell and Hunter Stockwell and Hunter 1985). Overlap values are 1985) the wood frog was the most co1T1110n calculated as CAB = (CA+ Csl/2 and range from 1 amphibian, accounting for 59% of all (identical) to 0 (completely different), amphibian and reptile captures in pitfall 68 species of no amphibian or reptile is and limi to peatlands, several are fre snake quently associated with this habitat. The next r roost four-toed salamander is the best example. ies were the green This salamander is among the most secre (29% of total l; tive in the eastern United States. and it Rana pipien{l, 5% is infrequently collected even in areas sa amander Ambys- where it is relatively corm10n. Adults of tota 1; and pickerel inhabit hardwood and, less often, conifer ) , 1% of total. The ous forests most of the year, but they ~--v-~-- caught in low num- move to water in the spring. The eggs are bers in many vegetation types. Wood and usually deposited in a cavity within a green frogs were trapped in all vegetation clump of Spha~num moss directly over water types and at nearly all sites. Wood frogs (Blanchard 19 3; Bishop 1941). The moss were most abundant in forested bogs and may be in deep, shaded situations in mixed least abundant in streamside meadows, forests of hemlock, pine, and hardwoods, where the northern leopard frog was the in open larch meadows, or in a Spha§num most abundant species. Green frogs were heath bordering bog ponds (Bishop 1 41). most abundant in wooded heath and least Some nests have been found in fairly open abundant in moss-Chamaedaphne. Streamside bogs. The female usually stays with the meadow was the only vegetation type where eggs until just before they hatch (Breit neither wood nor green frog dominated. enbach 1982). Corrmunal nests may contain Four-toed salamander (Hemidactylium scuta the eggs of several females but only one tum) and mink frog (Rana septentr1onailST, or two guard them. Offen considered bog associates, were not recorded! The bog turtle (Clemmys muhlenbergii) occurs from Massachusetts, New York, and The presence of amphibian breeding Connecticut south along the Appalachians sites in or near the bogs studied by to north Georgia and South Carolina. It Stockwell and Hunter (1985) greatly influ is frequently associated with Sphagnum enced the number of individuals of each bogs (Barton and Price 1955; Ernst and species present. The survival, emergence, Barbour 1972; Bury 1979), but open, sedgy, and subsequent dispersal and capture of or shrubby fens and wet meadows are its newly transformed juveniles contributed to typical habitats (Carr 1952; Arndt 1977). high counts and great seasonal variation A muddy bottom seems to be the most impor of species breeding nearby. Juveniles tant requirement (Barton and Price 1955). constituted 85% of all anurans captured Arndt (1977) found bog turtle habitats in and 18% of all salamanders captured. Delaware to be characterized by meadows with a substrate of deep mud, numerous Stockwell and Hunter (1985) found lit small springs, constantly flowing clear tle variation in species composition or and relatively cool water, and an anasto richness in six out of eight vegetation mosing network of rivulets, shallow pools, types studied. The presence of secondary and muskrat runways. The water tempera pools did not increase species richness or ture was usually lower than the air temp abundance, nor alter species composition. erature. The pH ranged from 5.5 to 7.4 but was usually between 6.0 and 6.8. In the Northeast, however, the bog turtle is Brooks et al. (1987) found 13 species characteristic of calcareous, graminoid of amphibians and reptiles in six peat fens. lands of the Pocono region of Pennsylva nia. None of these species were common. The spotted turtle (Clemmys guttata), The five most frequently encountered spec a close relative of the bog turtle, is ies were the red-spotted newt (Notho found throughout the Northeast in the phthalmus viridescensJ (13 at 4 srnsT, sluggish water of bogs, swamps, and small bullfrog (Rana catesbeiana) (8 at 2 ponds with muddy bottoms, as well as cal sites), spring peeper (Hyla crucifer) (5 careous fens and other habitats (Pope at 2 sites), wood frog (Tat 3 sites), and 1939; Carr 1952; Ernst and Barbour 1972). green frog {3 at 2 sites). In northern New England, bogs may be more 69 important than farther south. At least, !stock et al. 1'::75, at the northern limit of its range in The egg, larval s of this southern Ontario and Quebec, the spotted mosquito are found within the water-filled turtle finds its main or only refuge in pitcher. The larvae live ·in upper small deep bog ponds and lakes with boggy water column where feed on detritis. margins (Cook et al. 1980). The midge Metriocnemus knabi is fre quently found ng -same pitcher 6.2 INVERTEBRATES with W. smithii (Buffington 1970). Mic.ge larvae occur-1n the lower portion of the Many invertebrates indigenous to bogs pitcher fluid where they feed on the mass and barrens are derived from an arctic or of entrapped prey (Knab l90S; Cameron et subarctic fauna, but others are typical al. 1977; Fish and Hall 1978; Rymal and Canadian Zone species that feed upon Folkerts 1982). The pupae are in a gela spruce, tamarack, cranberry, or other bog tinous mass attached to the pitcher wall p1 ants (Ferguson 1955). A number of above the water surface. The larvae of W. invertebrate species are restricted to smithii and M. knabi can be frozen in the peatlands, having obligate relationships pitcher for- months during the winter. with peatland plants. Aquatic inverte During this time the larvae void their brates of bogs include species adapted to guts of food material that would facili slow-moving, oxygen-depleted waters. The tate water crystal formation and cause low pH of bogs is lethal to many inverte death. Overwintering mortality of midge brates including earthworms, mayfly lar and mosquito larvae frozen in the pitcher vae, and aquatic mites (Svendsen 1957; fluid is usually less than 5% (Paterson Standen 1979). These acidic waters also 1971). prevent shell development on clams and snails that thrive in calcareous fens. The sarcophagid fly Blaesoxipha Species occurring in bog waters, e.g., fletcheri is an obligate associate of water boatmen (Corixidae) and whirligigs pitcher p-lants, including S. purpurea, and (Gyrinidae), can tolerate a pH as low as Sarcophaga sarraciniae is probably an 3.5 (Johnson 1985). obligate. ~larvae of these large flies develop in the pitcher where they feed on Pitcher plants (Sarracenia spp.) are the entrapped prey mass. They often occur the obligate host to more invertebrate in most of the pitcher plants in a bog but species than any other bog plant. At usually singly within individual pitchers least 16 arthropod species are obligates, as a result of cannibalism (Forsyth and and many more are possible obligates or Robertson 1975; Rymal and Folkerts 1982). frequent associates of pitcher plants (Rymal and Folkerts 1982). Only the The larvae of at least five species of northern pitcher plant, Sarracenia purpu moths feed exclusively on pitcher plants rea, is found in peatlands of the nortfl and three of these--two noctuids and a eastern states. At least eight arthropod tortrici d--are found on the northern species are found as obligate pitcher pitcher plant. Larvae of the noctuid plant associates of S. purpurea, and four Exyra rolandiana usually girdle the of these have been- found only on this pitcner with a narrow feeding canal and species (Rymal and Folkerts 1982). Ob1i cause the upper portion of the leaf to gate and probably obligate commensals wilt and fall over. Usually only one found within the water-filled pitcher larva occurs in each leaf where it feeds include a mosquito, a midge, two sarco on the inner portion, leaving the outer phagid flies, and a mite. Species that epidermis intact (Jones 1921; Rymal and feed exclusively on the tissue of the Folkerts 1982). The noctuid root borer northern pitcher plant include an aphid Papaipema appassionata feeds exclusively and three moths (Figure 47). The pitcher on the underground rhizomes of pitcher plant mosquito (Wyeo'!l)'ia smithii, includ plants. The burrowing activities of this ing W. haynei Dodge 1947) is the most caterpillar are particularly damaging and thoroughly studied species associated with frequently cause the entire clump of S. purpurea (Smith 1902; Price 1958; Buff- pitchers to wilt and die (Jones 1921; 1ngton 1970; Paterson 1971; Addicott 1974; Rymal and Folkerts 1982). Although this 70 011 !lower !ortricid moth-Em:iothenia daeckeana Feeding on lea! noctuid moth-Exyra ralandiana aphid-Macrosiphum jeanae Feeding in pitcher fluid mosquito-Wyeomyia smithii midge-Metriocnemus knabi sarcophagid lly-Sarcophaga sarraceniae sarcophagid lly-8/aesoxipha f/etcheri mite-Anoetus gibsoni Feeding on root noctuid moth-Papaipema appassionata Figure 47. Invertebrate associates of the pitcher plant (Sarracenia purpurea). is certainly the most damaging of the on the pitcher walls beneath the surface obligate herbivores of~· purpurea, it is of the liquid (Nesbitt 1954; Hughes and rarely abundant enough to affect pitcher Jackson 1958; Rymal and Folkerts 1982). plant populations within a bog. The third obligate lepidopteran grazer is the tor Many lepidopteran species are found in tricid moth Endothenia daeckeana. The bogs, and some are actually restricted to larvae of this moth feed only on the flow bogs (Forbes 1923, 1960; Ferguson 1955; ers and developing fruit. Larvae bore Brower 1974; Howe 1975; Opler 1985). into the ovary and consume the seeds. These are obligate associates of specific When mature, they bore down the flower larval food plants and, in some species, stalk where they pupate and emerge in the of specific adult nectar sources as well. spring through a pre-chewed exit hole Typical bog butterflies include such spec (Jones 1921; Hilton 1982; Rymal and Fol ies as the bog fritillary (Boloia eunomia kerts 1982). dawsoni), bog elfin (Incisalia lanoraieen sis), and bog copper (Lycaena epixanthe). Other obligate associates include an Maerolepidopteran species characteristic aphid and a mite. The aphid Macrosiphum of Northeastern bogs are listed in Table jeanae is currently known only from S. 10. ~urpurea in Canadian bogs (Robinson 1972T. 11 life stages of this aphid occur on the Many species of dragonflies and dam pitcher plant, and it is sometimes found selflies (order Odonata) are characteris in large numbers on the second-year leaves tic of Northeastern bogs (Howe 1921; (Robinson 1972). The mite Anoetus gibsoni Walker 1925, 1958; Garman 1927; Gibbs and feeds on pitcher plant prey and is found Gibbs 1954; Needham and Westfall 1955; 71 Table 10. Macrn!epidoptera characteristic of Northeastern State abbreviation in parentheses indicates that the most recent record frorn that state is prior to 1965. In New states, other than Connecticut, all such records are from before 1934. Source: Dale F. Schweitzer, The Nature Conservancy. Common Scienti fie Larval food plants Northeastern name name in Northeast United States b confirmed range rur.n Tl '!' nti.1ri1 l')L A I f"",r .k;,,..;, ·JTi'J i.. :../L_r\ Bog Boloria eunomia Unknown ME friti 11 ary -aawsoni ------ Jutta ar·ctic Oenei s utta Probably the sedge ME, NH _Ej_i op_h~r_tJ!:'l ssum Bog elfin Inc i sa l i a Black spruce ME, (NH) TanoraTensi s 1? Western pine Inc i sa 1 i a Probably black spruce l . ME c 1 f~ n EY-ypho:1 Bog copper Lycoana Cranberry 2 ME, NH, VT, ~pj~ifr1!~ NY, CT, RI, PA, MA Hessel 's Mitoura hesseli Atlantic white cedar 2 NH, MA, RI, liairstreak CT, NY INCH WORMS GE OMETR IDAE Chalky Unknown l or 2 ME, NH, MA, wav 0 NY, PA? ~ Epilis Cranberry, other .J ME, NH, MA, triTrlCataria CT, NY Itarne Mostly cranberry 2 ME, MA, NH -suJ'pn u r a ea Sharp lined Eufi doni a Various shrubs 3 ME, NH, MA, powder moth discopTiata CT, NY, PA? Cranberry Ematurga Shrubs, esp. My_!'ica, 3 ME, NH, MA, spanworm am1 tar1a heaths NY, PA Projecta Cleora projecta S1-1eet gale 3 ME, MA, NY? gray Blueberry Glena Blueberry, sand 3 ME, NH, MA, gray coanataria cherry, pin cherry (CT), NY, PA Metarranthis sp. Unknown 2? ME, MA, VT la'fe'rTflarTa CT, NY or authors Metarranthis Unknown 3 ME, MA, NY, amynssana CT (continued) 72 Table 10. Continued. ------· Common Scientific Larval food plants Habi tat3 name name in Northeast preference Northeastern United States confirmed rangeb ------. --- SATURN I IOAE Columbia Hyalophora Larch 2 ME silkmoth columbia TIGER MOTHS, ARCTI IDAE WOOLLY BEARS Bog Holomelina General 1 ME, VT? holomelina lamae Bog tiger GralTfllia sp. General 1 NH, VT, MA moth ( speci osa)? CT NOCTUIDAE Sun dew Hemipachnobia Sundews, changing 1 or 2 ME, MA, CT, cutworm subporphyrea to heaths in late NY, PA monochromatea ins tars Anomogyna Spruces? 4 ME, NH 1mper1 ta Anomogyna Blueberry, other 2 ME, NH, MA, young1i heaths, larch CT, NY, PA Tri chordestra Chokeberry, 2 ME, NY !_ll9_0_5_<1 probably others Maroonwing Si deri dis Unknown 3 ME, NY, MA maryx (RI), CT, NH, PA 1? Lasionycta sp. Unkno~m .L. ME. VT Small dark Anarta cordigera Heaths 1 ME, NH, MA, CT yellow underwing Thaxter's Li thophane Sweet gale, 3 ME, NH, NY, MA pinion thaxteri sweet fern RI, (CT), (PA) Northern Xyl otype Larch, several shrubs 2 ME, (NH?) broad sallow acadia Cranberry Epiglaea Cranberry, blueberry 3 ME. NH, MA blossomworm apiata CT. RI, NY PA 01 i gi a Probably a sedge 2 ME. NY, (MA) lillriUSc u1 a (RI) Apamea corrmoda Probably a sedge 2? ME ME. MA, NY Pitcher Papiapema Pitcher plants ?. plant borer appass1onata (CT) (continued) 73 Table 10. Concluded. Common Scientific Larval food plants Habi ta ta Northeastern name name in Northeast preference United States b confirmed range Chain fern Papiapema Chain fern MA, NY? borer stenocel is Fagitana Ferns 2? (ME), MA, CT 1 i ttera NY, ( Pft.?} Pitcher Exyra r. Pitcher plants 2 ME, MA, NY, pl ant moth rolandiana CT Syngrapna Leatherleaf ME, NH, NY m1crogamma nearct1ca Syngrapha Unknown 4 ME, NH montana Sungrapha Unknown 1 or 3 ME surena Sweet ga 1e Catocala Sweet gale 2 ME, NH, NY underwing coelebs Macrochilo Probably sedges ME, NH, MA l oui siana aHabi tats: l = bog ob 1 i gate; 2 = found in bogs and other acidic peatlands; 3 found also in pine barrens and occasionally other sites with abundant heaths; and 4 found also in the alpine zones of New England. bThe region covered is northeastern Pennsylvania and all of New England and New York. Since virtually no records from northern New Jersey bogs are available and since the fauna of southern New Jersey is so different from the rest of the Northeast, that state is not considered here. cApparently a bog species in New England, but not restricted to bogs in most of its range. Beatty and Beatty 1968, 1971; White and The banded bog ski11111er is perhaps the Morse 1973; Walker and Corbet 1975; Opler most geographically restricted bog odonate 1985). Examples of bog odonates include in the Northeast. This dragonfly is a such species as the southern bog darner glacial relic species that has been col (Go~haeschna antilope), banded bog skim lected at only a few coastal localities in mer Williamsonia lintneri), and boreal New Jersey, New York, Connecticut, Rhode bluet (Enallagma borealeJ (Table 11). Island, and New Hampshire but at 13 sites Odonate nymphs are obligate carnivores; in Massachusetts. Populations at many of therefore, the affinity of certain species these sites have been destroyed by urbani to bogs is a result of the prey availabil zation, and several others in densely pop ity rather than the presence of food ulated areas may be threatened in the near plants. future. At least seven extant populations 74 Odonates characteristic of Northeastern This list contains only species a pro- nounced for peat bogs, and, therefore, not ail sptic1t;s occurring in bogs are included. Source: Chris Leahy. Massachusetts Audubon Society. Species name Habitat Confirmed Northeastern rangeb Forest zonec relationshipa Coenagri oni dae " __c__ __,,_ __ o_n .S~..':'.."._~~ ~ BA ME, NH, VT, MA, CT, RI, NY, PA, NJ NH, AO Co_~n~3ri on l_ri_!erroga_:tum BO/BA ME, VT SF Ena'l lagma bor_eal~ BA ME, NH, VT, MA, CT, RI, NY Neh~lennia 2.!:~c_!_l_~ BO ME, NH, VT, MA, CT, RI, NY, PA, NJ SF, NH, AO Aeshnidae Gomphaeshna furcil BO ME, VT, NH, MA, CT, RI, NY, PA, NJ NH, AO Aeshna i nterrupta BA ME, NH. VT, MA. NY SF, NH A. juncea BA NH SF A. sitchensis BO ME SF A. tic a BO ME, NH SF A. tubercul ifera BA ME, NH, VT, MA, CT, RI, NY, PA NH, AO Cordul ii dae Williamsonia fletcheri BO ME, MA, VT SF, NH W. lintnerie BO MA, NH, (RI, NY, NJ) f NH, AO Do roe or du l~ l ep i da BA ME, Vt, NH, MA, CT, RI, NY, PA, NJ NH, AO D. l iberia BA ME, NH, VT, MA, CT, RI, NY, PA, NJ NH, AO Somatochlora albicincta BA NH, NY SF S. frankl ini BO ME, NH SF S. incurvata BO ME SF, NH S. l Cordulia shurtleffi BA ME, NH, VT, MA, CT, NY, PA, NJ SF, NH, AO Epi_1:._heca_ cani BA ME, NH, VT, MA, CT, NY, PA SF, NH Libellul idae Nannothemis bella BO ME, NH, VT, MA, CT, RI, NY, PA, NJ SF, NH, AO Libellula quadrimaculata BA ME, NH, VT, MA, CT, PA, NJ SF, NH, AO BA ME, NH, MA, VT, CT, NY, PA, NJ NH, AO (continued) 75 Table 11. Concluded. Species name Habitat a Confirmed Northeastern Forest zonec relationship _,, ------·-· -- Sympe!ru_111 ~_ >JU Mn . ~, i ; rT Gf, '~"" ,;_ ~ VT, 'IV PA SF. NH ' L. hudsonica BA ME, NH, VT, MA, CT, [{I, NY, PA SF, NH BA ME, NH, VT, MA, CT, NY SF, NH aBO =Bog obligate--Species breeds exclusively (or nearly so) in bog ponds/pools, Sphagnum ponds, slow streams flowing through bogs and/or spring bogs. ~BA= Bog associate--Species showing strong affinity for bog conditions (see above), and frequently encountered in such situations in the tfortheast but having a more broadly defined ecotype. Includes some unpublished state records in the collection of Paul S. Miliotis. cSF = Spruce-fir NH = Northern hardwoods AO= Appalachian oak dEspecially spring bogs. eCandidate for endangered status. fKnown stations in these states no longer extant. gRequires some flow. are thought to remain--one in Connecticut, Wildlife (Federal Register 1984), is pro one in New Hampshire, and five in Massa posed for State listing in New Hampshire, chusetts. and is on the official State list in Mas sachusetts. The nymph of the banded bog skimmer lives in deep, cold bog ponds and canals The sphagnum cricket (Nemobius ~ that do not dry up in late summer or tri s), the smallest cricket in New-trig freeze solid in winter (White and Raff Tarlcf, appears to be limited to bogs (Morse 1970). This is a very early-flying dra 1920). gonfly, and adults are seen from about the first of April to mid June, before most Many groups of peatland invertebrates other species have emerged (Howe 1923). are still poorly known, and further study The adult is found in bogs or woodlands will undoubtedly reveal additional peat adjacent to Sphagnum bogs. land obligates. Insect groups that war rant particular attention in future bog studies include Ephemeroptera (mayflies), Bick (1983) listed the banded bog Hemiptera (bugs), Homoptera (hoppers and skimmer as "Vulnerable" in his list of aphids), Coleoptera (beetles), Diptera "Odona ta at risk in the conterminous (flies), and Hymenoptera (wasps and ants). United States and Canada." The banded bog Arachnida (spiders and mites), Myriapoda skimmer is a candidate for listing on the (millipedes and centipedes), and Protozoa Federal list of Threatened and Endangered in peatlands are also poorly known. 76 CHAPTER 7. HUMAN DISTURBANCES AND THREATENED BIOTA 7.1 PEAT MiNING leave an area of open water. Here, the fibric peat of peat bogs and the nuck of Although peat has been used as a fuel mesotrophic cedar swamps are mined. for hundreds of years in other parts of the world, it has never been an important In the large raised bogs of northeast source of domestic fuel in North America. ern Maine, peat is collected by large vac Nevertheless, it has been mined for this uum machines that suck up the dry peat. purpose in a few isolated bogs in the This method removes only thin layers of Northeast (Hills and Hollister 1912). In peat each year, but it requires harvesting North America, peat is used mainly in hor over areas of 1000 acres or larger. Thus, ticulture and agriculture because of its extensive areas of peatland can be dis abi1 ity to retain water. Most of it is turbed in a few years. Peat cutting was used as a mulch, soil conditioner, or pot carried out in Maine up to about 1960. ting soil. The upper, mostly living parts This operation disturbs smaller areas but of the Sehagnum plants are also used for leaves deep scars (Figure 48). air layering in greenhouses. Species of the Palustria group, e.g., S~hagnum papil Regeneration of disturbed peatlands is losum and S. ma2ellanicum ( igures zo-aild very slow, even of bogs harvested by the zrr;-are m0st suitable for that purpose. vacuum method. It takes decades for a closed vegetation to develop on a denuded In recent years there has been an peat surface. Figure 49 shows the surface increased interest in peat as an energy of a raised bog (plateau bog) 9 years source, especially for electric power after harvesting stopped. Eriophorum plants. Bogs large enough for develop spissum is usually the first colonizer. ments of this kind are found only in Growth and establishment is slow because Maine. Thus far, none of them are used of the extreme nutrient deficiency of the for this purpose. peat and frost heaving of seedlings by ice needles in spring and fall. Regeneration Consequently, peat is mined on a small after peat cutting (Figure 48) requires scale in most of the region. Horticul much more time (Mornsjo 1969). tural peat moss is harvested on a cormier cial scale in northeastern Maine, and other peat mining operations are found in northeastern Pennsylvania. Peat mining 7.2 FIRES involves three processes: clearing of the vegetation, draining and mining. It Although some fires are caused by nat results in the destruction of the surface ural phenomena, most are caused by man. vegetation. Although S~hagnum plants can Fires are common in the peat bogs of the grow anywhere from 0.5 o over 10 cm per northern part of the region (Osvald 1928, year, peat accumulates very slowly, usu 1955), and they greatly affect the vegeta ally less than 1 nm/yr. Therefore, peat tion. is a nonrenewable resource, and mining results in the virtually permanent removal Fires set in the high Calama2rostis of the peat. vegetation of the lagg of a bog to improve conditions for deer hunting often also Peat-mining operations in the southern burned the bog vegetation. In addition, and central parts of the region generally many bogs were burned to improve berry n Figure 48. Raised bog from which peat was harvested by cutting. The ridges are the original peat bog surface. The trench is now occupied by Sphagnum species, Carex canescens, and Eriophorum spissum. The latter is especially abundant on the drier part in the background. Figure 49. Raised bog surface harvested by vacuum method. Photograph taken 9 years after harvesting stopped in this area. The surface vegetation and only a very thin layer of peat was removed. Eriophorum spissum is virtually the only colonizer. Dead rhizomes of ericaceous dwarf shrubs are clearly visible between the Eriophorum tussocks. 78 picking. These are o1ogical continued, but their nutd filters et al. 1976), clearly visible in the but recent studies indicate that this may Bogs are now burned by not be true and that the capacity for fires in adjacent blueberry . retention of certain elements, e.g., P can ter fire control during the burning of the be very limited 0'1almer 1974; Richardson blueberry barrens has also reduced this et al. 1978; Shaw and Reinecke 1983). The risk. ability of bogs to retain nutrients as well as other elements appears to be Fi res affect mostly the dry dwarf closely tied to their hydrology (Dam shrub and forest-covered parts of a bog. man 1978a, 1979b). Removal and retention The dwarf shrubs recover easily from of elements wn1 therefore depend on underground rhizomes and regain their water-level fluctuations as 'Nell as water original cover in 3-4 years. Large parts movement. This deserves further research. of many inland bogs formerly covered with an open forest now support a dwarf-shrub heath. Fires burn the reindeer mosses and kill most of the Sphagnum during the dry 7.4 RARE, THREATENED, AND periods. Several lichens colonize the ENDANGERED SPECIES burnt crust, e.g., Cladonia crispata, C. cristatella, C. vertici11ata, and C. p~xi Peat bogs are wet, nutrient-def1cient, data, and can become very abundant a ter and cold habitats strikingly different Trres (Darrman 1977). Burned dwarf-shrub from the surrounding uplands, as wel 1 as bogs can be recognized for decades by the from most other wetlands. Many plant low Sphagnum cover and the abundance of species reach their southern limit in peat Cladonia crispata. bogs. These species are often considered relics from an early postglacial period. Fires are uncoltlTlon in the topogenous However, they occur al so in many recent and soligenous mires of the southern and bogs (Hemond 1980), and the unusual habi central parts of the region because of the tat conditions in these bogs appear to be wet bog surface and the lower frequency of the primary factor controlling their pres fires in the surrounding areas. ent distribution. The greatest threat to bog organisms is habitat destruction. This is not limited to disturbances such 7.3 OTHER ANTHROPOGENIC EFFECTS as peat harvesting or drainage. Because of the extreme nutrient de ff ciency of Housing and resort developments bogs, these ecosystems are sensitive to threaten peat bogs, and probably are the changes in the surrounding uplands that major threat in the densely populated alter the nutrient input. southern part of the region. Peat bogs are destroyed directly by flooding or dig Since bogs become progressively ging to create lakes, and indirectly by smaller and less conmon southward, many enrichment of the bog water by septic tank bog species are considered rare in the effluents. Bog water is very nutrient southern part of the region and are deficient, and nutrient additions cause included on state lists of rare and endan drastic changes in the bog vegetation gered species. This concerns mostly spec (Malmer 1974; Goffeng et al. 1979; Shaw ies that are widely distributed northward and Reinecke 1983). The effect on the and become rare at the southern limit of vegetation and the penetration into the their range. These species w1ll not be bog depends on the properties of the effl listed here unless they are rare in the uent and especially the hydrology of the region as a whole. It should be empha bog. In addition to the illlTlediate effect sized, ho'Never, that their restricted dis on the vegetation, nutrient additions tribution can be of concern at the state accelerate decay processes. This is par level (Dowhan and Craig 1976; Wiegman ticularly important in nutrient poor bogs 1979; Crow et al. 1981). This applies to where decay is stimulated most by nutrient a large number of species in the bog additions. In these bogs, it can change flora; some of these are listed in Table also the topography of the bog surface. 9. 79 Mozt ~~:-d~ vertebrates ba reaching into northern require larger territories than can be the region make up a ial category. found in the sma11 bogs of the southern These species (Table 12) are rare region part of the region. Consequently, there al 1y and Rubus chamaemorus even nationa11y are no vertebrates in the Northeast that (Crow et ar:-r981). The Tatter is common, occur only in bogs. However, there are a however, in the bogs of the northeastern number of species closely associated with coastal parts of Maine (Darmian 1977; Crit bog habitats that would be adversely ical Areas Program 1981). Arethusa bul affected by the loss of these habitats. bosa occurs throughout the reg10n- and Vertebrates associated with peat bogs are beyond, but it is now rare or declining considered vulnerable and those proposed because of habitat destruction and col for listing on state rare or endangered lecting. It reaches its northern limit in species lists are listed in Table 13. the Southern Boreal Zone. In contrast to the others, it does not have a primarily The minimum size of critical habitat northern distribution. Its abundance in for some invertebrate species may be quite parts of Nova Scotia and Newfoundland small ( Opler 1985). One Massachusetts results from the common occurrence of colony of the bog copper butterfly suitable habitat. (Lycoana epixantha) survives in a bog less than 0.1 acre in size (Dale Schweitzer, The Nature Conservancy, pers. conrn.). The Severa 1 bog species with southern vulnerability of species dependent on bogs affinities reach their northern limit in is illustrated by the probable extinction the region, and several of the southern of 11 of the 17 known populations of the species in Table 9 are listed as rare in banded bog skil11!ler (Williamsonia lintneri) Maine (Critical Areas Program 1981). How in the wake of urbanization (Mass. Natural ever, these species often reach their Heritage Program files). northern limit on more nutrient rich or drier sites rather than in bogs. Species The present information on the distri of the New Jersey Pine Barren flora bution of bryophytes and fungi is too l im (Harshberger 1916; McCormick 1970), which i ted to indicate rare and endangered spec reach into the region, do not occur in the ies for these groups. The same applies to peat bogs described here but favor Chamae the rare invertebrates. However, addi cy~a ri s swamps and open areas with l!X.lcky tional information on the distribution of ra her than peaty soils. some of these can be found in Chapter 6. Table 12. The distribution of nationally or regionally rare plant species in peat bogs of the northeastern United States. The following categories are used: R-rare; + present; - ab sent; EX-extirpated. State Species ME NH VT MA RI CT NY PA Arethusa bulbosa Ra R R R + R + R Geocaulon lividum R R R R Rubus chamaemorus Ra R EX aBut frequent in bogs of northeastern coastal Maine. 80 Table 13. State rare and endangered 11ertebrate:s characteristic of northeastern peatlands. None ot these species is listed as threatened (T) or endangered (El at the national level. The following categories are used: S-species of special concern; R-rare; D-infrequent or declining; EX-extirpated; U-status undetermined. In addition, the presence ( + ) or absence ( - ) of a species Is shown if it did not fall into any of the other categories. The categories for birds are based on breeding records. ·--·-·------·---·------··-·------·-- -·--·-·-- ·--- ,.,_.---·~ ~ - ~·- State and Status of Li st , ___ -----~---" -~- ____ ., ____ ·--.. --~ ·------w------~---·------" -~- -··"····--·. ------ME NH VT MA RI CT NY PA Species proposed proposed propo~ed official proposed unoffi ci a 1 official official _. ___ , ___ ..,_ ------·-- -~----~------·-·~~------Bog turtle E 0 Spotted turtle T s s s + + Four-toed salamander + + s s + + Spruce grouse + + s T Three-toed woodpecker + s s Black-backed woodpecker + + s Gray jay + s s + Rusty blackbird + s + Pigmy shrew + + + u Southern bog lemming + 5 s s R Northern bog lemming T Woodland caribou EX EX EX ----·-·----~------·-----·--·------~------.. -·~----~--- 81 CHAPTER 8. RECOMMENDATIONS FOR RESEARCH This study revealed many major and additions and about the capacity of bogs critical gaps in our knowledge about the to retain nutrients and heavy metals. peat bogs of the northeastern United States. This applies to virtually all In addition to research on chemical aspects of these bogs and is especially fluxes for bogs as a whole, specific pro true for the topogenou s and sol i genou s cesses within peatlands need to be inves peatlands, which are most abundant in the tigated. Differences in decay of organic Northeast. Research is needed to fill matter affect surface topography, water these gaps and to understand the conse flow, and nutrient release. In spite of quences of anthropogenic changes to these its obvious importance, we know less about peat bogs. The general nature of the re decay rates and the microbial processes search needed is briefly discussed below. involved than about any other peatland process. 8.1 CLASSIFICATION OF PEAT BOGS Water chemistry changes rapidly after mineral-soil water enters a peatland, and The peat bogs in the northeastern this affects vegetation, peat chemistry, United States include a wide range of con and decay. An understanding of these pro ditions with respect to habitats, their cesses is critical for an evaluation of development, and processes. Ecological the impact of anthropogenic alterations to processes and chemical fluxes are closely the peatland or the surrounding uplands. tied to hydrological conditions. Because of fundamenta 1 differences in hydrology 8.3 HYDROLOGY among major peatland types, data obtained in one bog type may not apply to other The hydrology of very few bogs has types. Therefore, all research should be been studied in the northeastern United carried out in well-defined peatland States. Although the principles control- types. For this reason, an adequate 1 ing water mvement through bogs are well classification of peatlands is essential. established, their application to actual bog sites is difficult. The lack of data In this report we used a peatland on water flow within peatlands especially classification system based on hydrology hampers our understanding of processes in and vegetation type as a basis for a topogenous and soligenous peatlands. discussion of differences among bogs. However, this classification was based on Research needs to be focused on seep a very limited survey and inadequate plant age into and flow through bogs, and on community data. Clearly, this classifi evapotranspiration losses from bogs. cation needs to be refined to serve as a Seepage and evapotranspiration, through framework within which research can be their effect on water chemistry and water carried out. table fluctuations, have a major impact on ecological processes and vegetation pat terns. 8.2 ECOLOGICAL PROCESSES Variability in seepage flow along the We clearly need to know mre about bog border and difficulties in measuring nutrient and metal fluxes in peat bogs to seepage flow are major reasons for the learn about the consequences of nutrient limited infonnation available. These 82 problems need to be addressed by inte tation zonation in this subset of bog grated studies of the hydrology, water types. Careful strati graphical studies chemistry and vegetation of bogs. are needed to reconstruct the development of other peatlands, especially moat. ~ogs Evapotranspiration varies with vegeta and peatlands resulting from palud1f1ca tion and water level. Detailed analyses tion. Bryophytes are dominant in the sur of the variation in evapotranspiration face vegetation and preserve well in peat. within a peatland are required to under Consequently, subfossil bryophyte assem stand water chemistry changes in undis blages will show the sequence of vegeta turbed peatlands and to determine the tion changes on a site in much greater impact of drainage, peat removal, and detail than vascular plant remains or artificial lakes. traditional stratigraphic studies. Such investigations can indicate succession 8.4 VEGETATION during bog development as we 11 as recent vegetation changes. This report describes the comnon plant comnunities of peat bogs and related peat 8.6 FLORA AND FAUNA lands, but this classification is based on very 1 imited data. This study revealed The biology and ecology of peatland how poorly the bog vegetation of the organisms are poorly studied. Research on northeastern United States has been inves the flora and fauna should emphasize the tigated. Most botanical studies of peat basic ecology of the dominant species and lands have described their flora rather those of special concern, such as rare and than plant communities and community endangered species. dynamics. In addition, floristic surveys usually refer to bogs as a whole and pay The availability of a suitable habitat little or no attention to habitat is a precondition for the occurrence of differences within bogs. any organism. For rare and endangered species, the presence of the required The floristic composition of the vege habitat and its extent is critical for tation is a sensitive indicator of water their survival. Therefore, efforts to chemistry, water flow, and water table protect these species should be habitat fluctuations. Vegetation studies should oriented rather than species oriented. focus on establishing the relationship Habitat conditions in bogs are coupled to between environmental factors and the processes in the surrounding uplands. floristic composition of the vegetation. These uplands have a greater effect as bog This type of information is needed to: size decreases. Consequently, recommen dations for preservation and management (1) predict changes in vegetation result will have to differ with bog type and ing from anthropogenic alterations size, the nature of surrounding uplands, affecting the peatland; and climate. Restoration of bog habitats (2) use vegetation as an indicator of is almost impossible because of their habitat variation and to trace water sensitivity to changes in nutrient input flow within a peatland; and and hydrology, and the emphasis in (3) provide a vegetation-habitat classifi protecting rare species has to be on cation that can be used as a frame habitat preservation. work for studies on ecological pro cesses and the application of their The distribution of some organisms in results in wise management. bogs is little ~nown. This applies espe cially to fung1 and soil invertebrates. 8.5 BOG DEVELOPMENT AND SUCCESSION Research on these organisms should be encouraged to provide a more complete pic Our knowledge about succession in the ture of the flori stic and faunistfc compo peat bogs of the Northeast is based mainly sition of bog co11111Unities. This is also on that in lake-fill bogs which represent of biogeographic interest because bogs only a subset of the different types of have cold microcl imates and often repre bogs. Succession of bogs in general is sent the southernmost habitats for north often erroneously interpreted from vege- ern species. 83 The results of a11 of t'iis research the landscape will affect peatlands. In will be directly applicable to solving addition, it will provide a much-needed environmental problems concerning the framework for the application of research peatlands of the Northeast. This research results and for evaluating the relative will supply basic facts necessary to value of remaining peat bogs. assess how anthropogenic alterations in 84 REFERENCES Addicott, J. F. 1974. Predation and prey muhlenbergi, surveyed and augmented. colllTlunity structure: an experimental Copeia 19 5:159-165. study of the effect of mosquito larvae on the protozoan co11111unities of pitcher Beatty, A. F., and G. H. Beatty. 1971. plants. Ecology 55:475-492. The distribution of Pennsylvania Odo nata. Proc. Pa. Acad. Sci. 45:147-167. Allen, G. M. 1972. Extinct and vanishing manmals of the western hemisphere with Beatty, G. H., and A. F. Beatty. 1968. the marine malllTlals of all the oceans. Check list and bibliography of Pennsyl Cooper Square Publications, New York. vania Odonata. Proc. Pa. Acad. Sci. 620 pp. 42:120-129. Al t, G• L. , G. J • Ma tu l a , Jr. , F. W. A1t, Bellamy, O. J., and J. Rieley. 1967. and J. s. Lindzey. 1980. Dynamics of Some ecological statistics of a minia home range and movements of adult black ture bog. Of kos 18:33-40. bears in northeastern Pennsylvania. Proc. Int. Conf. Bear Res. Manage. Bent, A. C. 1932. Life histories of North 5:131-136. American gallinaceous birds. U.S. Nat. Mus. Bull. 162:1-490. American Ornithologist's Union. 1983. Check-list of North American birds. 6th Bent, A. C. 1953. Life histories of ed. 877 pp. North American warblers. U.S. Nat. Mus. Bull. 203 :1-734. Andrus, R. E. 1980. Sphagnaceae (p'eat moss family} of New York State. N.Y. Bick, G. H. 1983. Odonata at risk in State Mus. Bull. 442. 89 pp. conterminous United States and Canada. Odonatologica 12:209-226. Andrus, R. E. 1986. Some aspects of S~ha~num ecology. Can. J. Bot. Bishop, S.· c. 1941. The salamanders of 6 :4 6-426. New York. N.Y. State ttis. Bull. 324:1-365. Arndt, R. G. 1977. Notes on the natural history of the bog turtle, Cle!l!!lYs muh Blanchard, F. N. 1923. The life history lenbergf (Schoepff}, in Delaware. Ches of the four-toed salamander. Am. Nat. apeake Sci. 18:67-76. 57:262-267. Baden, w., and R. Eggelsmann. 1963. ZUr Boatman, O. J., P. D. Hulme, and R. w. Durchlassigkeit der Moorboden. Z. Kul Tomlinson. 1975. Monthly determina turtech. Flurberefnig. 4:226-254. tions of the concentrations of sodium, potassium, magnesium and calcium in the rain and in pools on the Silver Flowe Banfield, A. w. F. 1974. The ma11111als of National Nature Reserve. J. Ecol. Canada. University of Toronto Press, 63:903-912. 438 pp. Boelter, o. H. 1968. Impo~tant physical Barton, A. J., and J. W. Price, Sr. 1955. properties of peat materials. Pages Our knowledge of the bogturtle, Cle!!l!\Ys 150-156 in Proc. 3rd Int. Peat Congr. 85 Soc~ tc:-, n. !-!. !969. Physical propcrt~es Suc~ncr, ~ H. 195?b. Home range of of peats related to degree of decomposi SynaptollJYs cooperi. J. Mammal. 38:132 tion. Soil Sci. Soc. Am. Proc. 33:606-609. Buckner, C. H. 1966. Populations and ecological relationships of shrews in Boelter, D. H. and E. S. Verry. 1977. tamarack bogs of southeastern Manitoba. Peatland and water in the northern Lake J. Marrmal. 47:181-194. States. North Cent. For. Exp. Stn., U.S. Dep. Agric. For. Serv. Gen. Tech. Buell,M. F., andH. F. Buell. 1975. Rep. NC-31. 22 pp. Moat bogs in the Itasca Park area, Min nesota. Bull. Torrey Bot. Club 102:6-9. Bo:.trom, V., and L. Hans:>on. 1931. Sma11 rodent corrmunities on mires: implica Buffington, J. D. 1970. Ecological con tions for population performance in siderations of the cohabitation of other habitats. Oikos 37:216-224. pitcher plants by ~eOllJYia smithii and Metriocnumus knab . Mosq. News Bowen, H. J. M. 1979. Environmental 30:89-90. -- chemistry of the elements. Academic Press, N. Y. 333 pp. Burke, W. 1975. Fertilizer and other chemical losses in drainage water from Bradshaw, w. E. 1971. Photoperiodic tim blanket bogs. Irish J. Agric. Res. ing of development in the pitcher plant 14:163-178. mosquito ~eon1Yia smithii. Am. Zool. 11 :670-67 . Bury, B. 1979. Review of the ecology and conservation of the bog turtle, CleimtYS Breitenbach, G. L. 1982. The frequency of muhlenbergi. U.S. Fish Wildl. Serv. corrmunal nesting and solitary brooding Spec. SCi. Rep. Wildl. 219:1-9. in the salamander, Hemidac~lium scuta tum. J. Herpetol. 16:341- 6. Cameron, C. 1970. Peat deposits of southeastern New York. U.S. Geol. Surv. Brewer, R. 1967. Bird populations of Bull. 1317-B. bogs. Wilson Bull. 79:371-396. Cameron, C. C. 1974. Peat deposits of Brewster, w. 1925. The birds of the Lake northeastern Pennsylvania. U. S. Geol. Umbagog region of Maine. Bull. Mus. Surv. Bull. 1317-A, 90 pp. Comp. Zool. 66:1-402. Cameron, c. c. 1975. Some peat deposits Bromley, S. W. 1935. The original forest in Washington and southeastern Aroostook types of southern New England. Ecol. counties, Maine. U. S. Geol. Surv. Monogr. 5:61-89. Bull. 1317-C. 40 pp. Brooks, R. P., D. E. Arnold, and E. D. Cameron, C. C, and W. Anderson. 1980. Bellis. 1987. Wildlife and plant com Peat resources of The Great Heath, Wash munities of selected wetlands in the ington County, Maine. U.S. Geol. Surv. Pocono region of Pennsylvania. Report Open File Rep. 80/379. 31 pp. prepared for the U.S. Fish Wildl. Serv., Rep. Nat. Wetlands Res. Center. (In Cameron, C. J., G. L. Donald, and C. G. press.) Patterson. 1977. Oxygen - fauna rela tionships in the pitcher plant Sarrace nia eurpurea L. with reference to tfie Brower, A. E. 1974. A list of the Lepi CllTronomid Metriocnemus knabi Coq. Can. doptera of Maine. Part 1. The Macro J. Zool. 55:2018-2023. -- lepidoptera. Univ. Maine Life Sci. A~ric. Exp. Stn. Tech. Bull. 66:1-136. Cameron, C. c.• M. K. Mullen, C. A. Lepage and W. A. Anderson. Undated. Peat Buckner, C. H. 1957a. Population studies resources of Maine. Vol. 5: Washington on small mammals of southeastern Mani County. Maine Geol. Surv. Bull. 32. toba. J. Manmal. 38:87-97. 143 pp. 86 Carr, A. i952. Handbook of turtles. Com Coven t ry, A. F• 1942. SynaptoRJYs- - - cooperi stock Publications, Ithaca, N.Y. 522 pp. in forested regions. J. Mammal. 23:450-451. Clarke, F. w. 1924. The data of geochem istry. U. S. Geol. Surv. Bull. 770. Cowardin, L. M., V. Carter, F. C: Gol~t, 841 pp. and E. T. LaRoe. 1979. Class1f1cat1on of wetlands and deep water hab1 tats of Clymo, R. S. 1965. Experiments on break the United States. U.S. Fish Wildl. down of S~hagnum in two bogs. J. Ecol. Serv. Biol. Serv. Program FWS/OBS-79/31. 53:747-75 . 103 pp. Clymo, R. S. 1983. Peat. Pages 159-224 Cragg, J. B. 1961. Some aspects of the in A.J. P. Gore (ed.) Mires: swamp, bog, ecology of moorland animals. J. Anim. ren and moor. Vol. A: General studies. Ecol. 30:205-221. Elsevier Scientific Publications, Amsterdam. Crisp, o. T. 1966. Input and output of minerals for an area of Pennine moor Clymo, R. S. 1984. The limits to peat land: the importance of precipitation, bog growth. Philos. Trans. R. Soc. drainage, peat erosion, and animals. J. Lond. B. Biol. Sci. 303:605-654. Appl. Ecol. 3 :327-348. Collins, J. T., R. Conant, J. E. Huheey, Critical Areas Program. 1981. Rare vas J. L. Knight, E. M. Rundquist, and H. M. cul ar pl ants of Maine. State Planning Smith. 1982. Standard co11111on and sci Office, Augusta, Maine. 656 pp. entific names for North American amphi bians and reptiles. 2nd ed. Society for the Study of Amphibians and Reptiles. Crossley, A., and J. R. Gilbert. 1983. 28 pp. Home range and habitat use of female moose in northern Maine - a preliminary Committee on Atmospheric Transport and look. Trans. Northeast Sect. Wildl. Chemical Transformations in Acid Precip Soc. 40:67-75. itation. 1983. Acid deposition: atmospheric processes in eastern North Crow, G. E.. W. D. Countryman, G. L. America. National Acadell\Y Press, Wash Church, L. M. Eastman, C. B. Hellquist, ington, D.C. 375 pp. L. J. Mehrhoff, and I. M. Storks. 1981. Rare and endangered vascular pl ant spec ies in New Engl and. Rhodora 83 :259-299. Connor, P. F. 1953. Notes on the mammals of a New Jersey Pine Barrens area. J. Crum, H. A., W. C. Steere, and L. E. Mammal. 34:227-235. Anderson. 1973. A new list of mosses of North America north of Mexico. Connor, P. F. 1959. The bog lemming Bryologist 76:85-130. Synapto~s cooperi in southern New Jer sey. Pu 1. Mus. Mich. State Univ. Biol. Damman, A. W. H. 1977. Geographical Ser. 1:161-248. changes in the vegetation pattern of raised bogs in the Bay of Fundy region Cook F. R., J. D. Lafontaine, S. Black, L. of Maine and New Brunswick. Vegetatio Luciuk, and R. V. Lindsay. 1980. Spot 35:137-151. ted turtles (Cle!mJYS guttata) in eastern Ontario and adjacent Quebec. Can. Field Nat. 94:411-415. Da11111an, A. W. H. 1978a. Distribution and movement of elements in ombrotrophic peat bogs. Oikos 30:480-495. Cook, R. P. 1983. Effects of acid precip itation on embryonic mortality of Ant>ys Oamman~ A: W. H. 1978b. Ecological and toma salamanders in the Connecticut'"'Vil fl or1 st1 c trends in ombrotrophi c peat ley of Massachusetts. Biol. Conserv. bogs of eastern North America. Colloq. 27:77-88. Phytosociol. (Lille) 7:61-79. 87 Dalllllan, A. w. H. 1979a. Geographic pat Dowhan, J. J .• and R, ,L Craig. 1976. terns in peatland development in eastern Rare and endangered species of Connecti North America. Pages 42-57 in Kivinen, cut an~ their habitats. Conn. Geol. E., L. Heikurainen, and P. -P-akarinen, Nat. H1st. Surv. Rep. Inves. 6. 137 pp. eds. Classification of peat and peat lands. Proc. Symp. Int. Peat Soc. DuRietz, E. 1954. Die Mineralboden- wasserzeigergrenze als Grundlage einer Da111T1an, A. w. H. 1979b. Mobilization and natUrlichen Zweigliederung der nord- und accumulation of heavy metals in freshwa mitteleuropaischen Moore. Vegetatio ter wetlands. U.S. Dep. Inter. Rep. 5-6:571-585. OWRT Project A-073-CONN. 14 pp. Dutcher, B. H. 1903. Marrmals of Mt. Dalllllan, A. w. H. 1986. Hydrology, devel Katahdin, Maine. Proc. Biol. Soc. Wash. opment, and biogeochemistry of ombroge 16:63-71. nous peat bogs with special reference to nutrient relocation in a western New Eggelsmann, R. 1960. Uber die Hohenan- foundland bog. Can. J. Bot. 64:384-394. derungen der Mooroberflache infolgen von Sackung und Humusverzehr sowie in Abhan Damman, A. w. H. 1988. Regulation of gigkeit von Azi ditat, "Atmung" und nitrogen removal and retention in peat anderen Einflussen. Mitt. Moor-Ver lands. Oikos 51. (In press.) suchsstn. Bremen 8:99-132. Damman, A. w. H., and J. J. Dowhan. 1981. Elowe, K. D. 1984. Home range, move- Vegetation and habitat conditions in ments, and habitat preferences of black Western Head Bog, a southern Nova Sco bear (Ursus americanus) in western Mas tian plateau bog. Can. J. Bot. sachusetts. M.S. Thesis. University of 59:1343-1359. Massachusetts, Amherst. 112 pp. Dansereau, P., and F. Segadas-Vianna. Ernst, C. H., and R. W. Barbour. 1972. 1952. Ecological study of the peat bogs Turtles of the United States. Univer of eastern North America .. I. Structure sity of Kentucky Press, Lexington. 347 and evolution of vegetation. Can. J. pp. Bot. 30:490-520. Erskin, A. J. 1977. Birds in boreal Can Davis, R. B., G. L. Jacobson, L. S. ada. Can. Wildl. Serv. Rep. Ser. Widoff, and A. Zlotsky. 1983. Evalua 41 :1-71. tion of Maine peatlands for their unique and exemplary qualities. Maine Depart Eurola, S., and R. Ruuhijarvf. 1961. ment of Conservation, Augusta. 186 pp. Ober die regionale Einteilung der fin nischen Moore. Arch. Soc. Zool. Bot. Fenn. Vanamo 16 (Suppl.):49-63. Department of the Interior, Fish and Wild life Service. 1984. Endangered and threatened wildlife and plants; review Eveland, J. F. 1973. Population dynam- of invertebrate wildlife for listing as ics, movements, morphology, and habitat endangered or threatened SRecies. Fed characteristics of black bears in Penn eral Register 49:21664-21675. sylvania. M.S. Thesis. Pennsylvania State University, University Park. 157 pp. Dodds, D. G. 1974. Distribution, habitat, and status of moose in the Atlantic Ewert, D. 1982. Birds in isolated bogs in provinces of Canada and northeastern central Michigan. Am. Midl. Nat. United States. Naturaliste Can. 101 :51 M65. 108:41-50. Ferguson, D. C. 1955. The Lepidoptera of Dodge, H. R. 1947. A new species of Nova Scotia. Part 1 (Macrolepidoptera). ~eo'!ll'.ia from the pitcher plant. Proc. Bull. Nova Scotia Mus. Sci. (Halifax) ntomol. Soc. Wash. 49:117-122. 2:1-375. 88 Fernald, M. L. 1950. Gray's Manual of Goffeng, G., S. Saeb)l, and L. E. Maugen. Botany. 8th ed. American Book Co., New 1979. Action of effluent from a tourist York. 1632 pp. center on a peatland ecosystem in Nor way. Pages 332-340 in Kivinen, E., L. Fish, D., and D. W. Hall. 1978. Succes Heikurainen, and P.---Pakarfnen, eds. sion and stratificaton of aquatic Classification of peat and peatlands. insects inhabiting the leaves of the Proc. Symp. Int. Peat Soc. insectivorous pitcher plant, Sarracenia purpurea. Am. Midl. Nat. 99:172-183. Goode, D. A., A. A. Marsan, and J-R. Forbes, W. T. M. 1923. Lepidoptera of Michaud. 1977. Water resources. Pages New York and neighboring states. Part 299-331 in Radforth, N. W., and C. O. 1. Mem. Cornell Univ. Agric. Exp. Stn. Brawner,~eds. Muskeg and the northern Mem. 68:1-729. environment in Canada. University of Toronto Press. Forbes, W. T. M. 1960. Lepidoptera of New York and neighboring states. Part Goodwin, G. G. 1932. New records and some 4. Mem. Cornell Univ. Agric. Exp. Stn. observations on Connecticut manmals. J. Mem. 371:1-188. Mammal. 13:36-40. Forbush, E. H. 1927. Birds of Massachu Gore, A. J. P., ed. 1983. Mi res: swamps, setts and other New England states. bog, fen and moor. Vol. A. Analytical Vol. 2. Mass. Dep. Agric. 461 pp. studies. Elsevier, Amsterdam. 438 pp. Forsyth, A. B., and R. J. Robertson. Gorham, E. 1956. On the chemical compo 1975. K-reproductive strategy and lar sition of some waters from the Moor val behavior of the pitcher plant sarco House Nature Reserve. J. Ecol. phagid fly, Blaesoxipha fletcheri. Can. 44:375-382. J. Zool. 53:174-179. Gorham, E. 1961. Factors influencing Forrest, G. I., and R. A. H. Smith. 1975. supply of major ions to inland waters The productivity of a range of blanket with special reference to the atmos bog vegetation types in the northern phere. Geol. Soc. Amer. Bull. Pennines. J. Ecol. 63:173-202. 72 : 795-840. Ganong, w. F. 1897. Upon raised peat Gosner, K. L., and I. H. Black. 1957. bogs in the province of New Brunswick. The effects of acidity on the develop Trans. R. Soc. Can. Ser. 2(3):131-163. ment and hatching of New Jersey frogs. Ecology 38:256-262. Garman, P. 1927. Guide to insects of Con necticut, Part V: The Odonata or dra Granhall, u., and H. Selander. 1973. gonflies of Connecticut. Geol. Nat. Nitrogen fixation in a subarctic mire. Hist. Surv. Bull. 39:1-331. Oikos 24:8-15. Gauthier, R., and M. M. Grandtner. 1975. Etude phytosociologique des tourbieres Granlund, E. 1932. De svenska hogmo~sar du Bas Saint-Laurent, Quebec. Natural nas geologi. Sver. Geol. Unders. Arsb. iste Canad. 102:109-153. 26:1-193. Gibbs, R. H., and S. P. Gibbs. 1954. The Grigal D. F. 1985. Sphagnum production Odonata of Cape Cod, Massachusetts. N. in f~rested bogs of northern Minnesota. Y. Entomol. Soc. 62:167-184. Can. J. Bot. 63:1204-1207. Glaser, P., G. A. Wheeler, E. Gorham, and Grigal, D. F., C. G. Buttleman, and L. K. H. E. Wright. 1981. The patterned Kernik. 1986. Biomass productivity of mires of the Red Lake peatland, nor~hern the woody strata of forested bogs in Minnesota: vegetation, water chem1stry northern Minnesota. Can. J. Bot. (In and landforms. J. Ecol. 69:575-599. press.) 89 Groet, S. S. 1976. Regional and local Hills, J. L., and F. M. Hv11ister. 1912. variation in heavy metal concentrations The peat and muck deposits of Vermont. of bryophytes in the northeastern United Vermont Agric. Exp. Stn. Bull. States. Oikos 27:445-456. 165:139-240. Hale, M. E., and Culberson, W. L. 1966. Hilton, D. F. J. 1982. The biology of A third checklist of the lichens of the Endothenia daeckeana (Lepidopt continental United States and Canada. era:Olethreutidae}, an inhabitant of the Bryologist 69:141-182. ovaries of the northern pitcher plant, Sarracenia purpurea (Sarraceniaceae). Hamilton, W. J., Jr. 1941. On the occur Can. Entomol. 114:269-274. ren~e of Syna~OlllYS coo~eri in forested regions. nunal. 22: 95. J. Hooghoudt, S. B. 1937. Die Bohrlocher methode zur Ermittlung der Durchlassig Hardin, D. L. 1975. Animal conmunity keit des Bodens und ihr Nutzen fur die structure of Adirondak wetlands. M.S. Praxis. KoR111. Int. bodenk. Ges. Thesis. State University of New York, (Zurich) B, Verh. 6:42-57. Syracuse. 191 pp. Howe. R. H. • Jr. 1921. The di stri but ion Harrison, C. 1978. A field guide to the of New England Odonata. Boston Soc. nests, eggs and nestlings of North Nat. Hist. Proc. 36:105-133. American birds. Wm. Collins, Cleveland. 416 pp. Howe, w. H. 1975. The butterflies of North America. Doubleday, New York. 633 pp. Harshberger, J. W. 1916. The vegetation of the New Jersey Pine Barrens. Sower, Hughes, R. D., and C. G. Jackson. 1958. Philadelphia. 284 pp. A review of the Anoetidae (Acari). Va. J. Sci. 9:5-198. Hayward, P. M., and R. S. Clymo. 1982. Profiles of water content and pore size Ingram, H. A. P. 1978. Soil layers in in Sphagnum and peat, and their relation mires: function and terminology. J. to peat bog ecology. Proc. R. Soc. Soil. Sci. 29:224-227. Lond. B. Biol. Sci. 215:299-325. Heal, 0. W., and D. F. Perkins. 1978. Ingram, H. A. P. 1982. Size and shape in Production ecology of British moors and raised mire ecosystems: a geophysical montane grasslands. Ecological Studies model. Nature 297:300-303. 27. Springer-Verlag, New York. 426 pp. Ingram, H. A. P. 1983. Hydrology. Pages Heikurainen, L., J. Paivanen, and J. Sar 67-158 in A. J. P. Gore, ed. Mires: asto. 1964. Ground water table and swamp, oog, fen and moor. Elsevier Sci water content in peat soil. Acta For. entific Publications, Amsterdam. Fenn. 77(1):1-18. !stock, C. A., S. S. Wasserman, and H. Hemond, H. F. 1980. Biogeochemistry of Zintner. 1975. Ecology and evolution of Thoreau's Bog, Concord, Massachusetts. the pitcher plant mosquito. 1. Popula Ecol. Monogr. 50:507-526. tion dynamics and laboratory response to food and population density. Evolution Hemond, H. F. 1983. The nitrogen budget 29:296-312. of Thoreau's Bog. Ecology 64:99-109. Ivanov, K. E. 1957. Osnovy gidrologii bolot lesnoi zony (Principles of bog Henttonen, H., A. Kaikusalo, J. Tast, and hydrology for the forest zone). Gidro J. Viitala. 1977. Interspecific compe meteoizdat, Leningrad. 500 pp. tition between small rodents in subarc tic and boreal ecosytems. Oikos Ivanov, K. E. 1975. Vodoobmen v bolot 29:581-590. nykh landschaftakh (Water movement in 90 peat landscapes). Gidrometeoizdat, Len lar emphasis on Pi~e County. M.S. The ingrad. 280 pp. sis. Pennsylvania State University, University Park. 77 pp. Ivanov, K. E. 1981. Water movement in mirelands. Academic Press, London. 278 Kratz, T. K., and C. B. DeWitt. 1986. pp. Internal factors controlling peatland lake ecosystem development. Ecology Jarvinen, 0., and L. Sammal isto. 1976. 67:100-107. Regional trends in the avifauna of Finn ish peatland bogs. Ann. Zool. Fenn. Landers, J. L., R. J. Hamilton, A. S. 13:31-43. Johnson, and R. L. Marchinton. 1979. foods and habitat of black bears in Johnson, C. W. 1985. Bogs of the North southeastern North Carolina. J. Wildl. east. Univ. Press New England, Hanover. Manage. 43:143-153. 269 pp. Johnson, E. A. 1977. A multivariate Laughlin, S. B., and D. P. Kibbee. 1985. analysis of the niches of plant popula The atlas of breeding birds of Vermont. tions in raised bogs. I. Niche dimen Vermont Institute Natural Science, Wood sions. Can. J. Bot. 55:1201-1210. stock. 456 pp. Jones, F. M. 1921. Pi tcher-p 1 ants and Laundre, J. A. 1980. Heavy metal distri their moths. Nat. Hist. 21:297-316. bution in two Connecticut wetlands: a red maple swamp and a Sphagnum bog. Jones, J. K., Jr., D. C. Carter, H. H. M.S. Thesis. University of Connecticut, Genoways, R. S. Hoffmann, and D. W. Storrs. 56 pp. Rice. 1982. Revised checklist of North American mannnals north of Mexico. Mus. Lindzey, J. S., W. S. Kordek, G. J. Texas Tech. Univ. Occas. Papers 80:1-22. Matula, and W. P. Piekielek. 1976. The black bear in Pennsylvania - status, Judd, W. W. 1959. Studies of the Byron movements, values, and management. Bog in southwestern Ontario. X. Inqui Proc. Int. Conf. Bear Res. Manage. lines and victims of the pitcher plant, 3:215-224. Sarracenia purpurea L. Can. Entomol. 91 : 171-180 . Linzey, A. V. 1983. Synapto11lYs cooperi. Junge, C. E. 1958. The distribution of Mammal. Species 210:1-5. ammonia and nitrate in rain water over the United States. Trans. Am. Geophys. Linzey. A. V. 1984. Patterns of coexis Union 39:241-248. tence in S)napto"'t:s cooperi and Microtus pennsylvan cus. cology 65:382-393. Karns, D. R. 1979. The relationship of amphibians and reptiles to peatland Linzey, A. V., and J. A. Cranford. 1984. habitats in Minnesota. Minnesota Habitat selection in the southern bog Department of Natural Resources. 84 pp. le11111ing, Syna~to11lYs cooperi, and the meadow vole, M1crotus henns~lvanicus, in Knab, F. 1905. A chironomid inhabitant Virgfofa. Can. Field at. 8:463-469. of Sarracenia purpurea, Metriocnemus knabi Cog. J. N. Y. Entomol. Soc. Livett, E. A•• J. A. Lee, and J. H. Tal IT:09"-73. l is. 1979. lead, zinc, and copper analyses of British blanket peats. J. Knight, O. W. 1904. Contributions to the Ecol. 67:865-892. life history of the yellow palm warbler. J. Maine Ornith. Soc. 6:36-41. Lyons, L. A. 1981. The effect of pond water on the surface enrichment of a Kordek, W. S. 1973. An investigation of floating Sphagnum bog. M.S. Thesis. the structure, stability, and movements University of Connecticut, Storrs. 46 of Pennsylvania black bear with particu- pp. 91 Maliner, N.. 1962a. Studic;; vn fii1t2 vc;c ~orr.~jo, T_ !969. Studies on vegetation tation in the Archaean area of south and development of a peatland in Scania, western Gotaland (South Sweden). I. Veg South Sweden. Opera Bot. 24:1-187. etation and habitat conditions on the Akhult mire. Opera Bot. 71:1-322. Morse, A. P. 1920. Manual of the Orthoptera of New England, including the Malmer, N. 1962b. Studies on mire vege locusts, grasshoppers, crickets, and tation in the Archaean area of south their allies. Proc. Boston Soc. Nat. ~estern Gotaland. II. Distribution and Hist. 35:197-556. seasonal variation in elementary con stituents on some mire sites. Opera Bot. 7(2};1-67. Muir, R. D. 1977. Wildlife, conserva- tion, and recreation. Pages 352-366 in Malmer, N. 1974. Erfarenheter av rotslam N. W. Radforth and C. O. Brawner, edS: deponering inom ett rJ\Yromrade. Statens Muskeg and the northern environment in Naturvardsverk. SNV PM 441. 205 pp. Canada. University of Toronto Press. Malmer, N. 1985. Remarks to the classi Munger, J. W., and S. J. Eisenreich. fication of mires and mire vegetation: 1983. Continental-scale variations in Scandinavian arguments. Aquilo Ser. precipitation chemistry. Environ. Sci. Bot. 21:9-17. Technol. 17:32A-42A. Malmer, N. and E. Holm. 1984. Variation Needham, J. G., and M. J. Westfall, Jr. in the C/N quotient of peat in relation 1955. A manual of the dragonflies of to decompo~ioion rate and age determina- North America (Anisoptera). University tion with Pb. Ofkos 43:171-182. of California Press. 615 pp. Malmer, N. and B. Nihlgard. 1980. Supply Nesbitt, H. H. J. 1954. A new mite, and transport of mineral nutrients in a Zwickia gibsoni n. sp., Fam. Anoetidae, sub-arctic mire. Pages 63-95 in Sones from the pitchers of Sarracenia purpurea son, M., ed. Ecology of a Slibarctic L. Can. Entomol. 86:193-197. mi re. Ecol. Bul 1. (Stockholm) 30. Manville, R. H. 1960. Recent changes in Neuhausl, R. 1975. Hochmoore am Teich the marrmal fauna of Mount Desert Island, Velke Darko. Vegetace CSSR, A9., Acad. Maine. J. Marrmal. 41:415-416. Verl. Tschechoslov. Akad. Wissensch, Prag. 276 pp. Marshall, W. H., and M. F. Buell. 1955. A study of the occurrence of amphibians Nichols, G. E. 1915. The vegetation of in relation to a bog succession, Itasca Connecticut. IV. Plant societies in State Park, Minnesota. Ecology lowlands. Bull. Torrey Bot. Club 36:381-387. 42:169-217. Nordquist, G. E., and E. C. Birney. 1980. Mason, C. F., and V. Standen. 1983. The importance of peatland habitats to Aspects of secondary production. Pages small mammals in Minnesota. Minnesota 367-382 in A.J.P. Gore, ed. Mires: Department of Natural Resources. 186 swamp, bog, fen and moor. Elsevier Sci pp. entific Publications, New York. McCormick, J. 1970. The pine barrens: a Opler, P. A. 1985. Invertebrates. Pages preliminary ecological inventory. N. J. 79-165 in H. H. Genoways, and F. J. State Mus. Rep. 2. 103 pp. Brenner~, eds. Species of special con cern in Pennsylvania. Carnegie r.tis. MOrnsjo, T. 1968. Stratigraphical and Nat. Hist. Spec. Publ. 11:1-430. chemical studies on two peatlands in Scania, South Sweden. Bot. Not. Osvald, H. 1928. Nordamerikanska moss 121:343-360. typer. Svensk Bot. Tidskr. 22:377-391. 92 Osvald, H. 1955. The vegetation of two Preble, E. A. 1899. Description of a raised bogs in northeastern Maine. new lel11lling mouse from the White Moun Svensk Bot. Tidskr. 49:110-118. tains, New Hampshire. Proc. Biol. Soc. Wash. 13 :43-45. Osvald, H. 1970. Vegetation and stratig raphy of peatlands in North America. Price, R. D. 1958. Notes on the biology Acta Univ. Uppsala, Ser. V, C (1):1-96. and laboratory colonization of Wyeof11Yia smithii (Coquillet). Can. Intomo1 Overbeck, F. and Happach, H. 1957. Uber 90:473-478. . das Wachstum und der Wasserhaushalt ein iger Hochmoorsphagnen. Flora Reader, R. J., and J. M. Stewart. 1972. 144:335-402. The relationship between net primary production and accumulation for a peat Pakarinen, P. 1978a. Production and nut land in southeastern Manitoba. Ecol ogy rient ecology of three Sphagnum species 53: 1024-1037. in southern Finnish raised ogs. Ann. Bot. Fenn. 15:15-26. Rebertus, A. J. 1986. Bogs as beaver habitat in north-central Minnesota. Am. Pakarinen, P. 1978b. Distribution of Midl. Nat. 116:240-245. heavy metals in the Sphagnum layer of bog hummocks and hollows. Ann. Bot. Fenn. 15: 287-292. Richardson, C. J., J. A. Kadlec, W. A. Wentz, J. P. M. Chamie, and R. H. Kad- Palmer, R. S. 1949. Maine birds. Bull. 1ec. 1976. Background eco 1 ogy and the Mus. Comp. Zool. 102:1-656. effects of nutrient additions on a cen tral Michigan wetland. Pages 34-72 in M. W. Lefor, W. C. Kennard, and T. r. Paterson, C. G. 1971. Overwintering Helfgott, eds. Proceedings Thi rd Wet ecology of the aquatic fauna associated land Conference, Univ. Conn. Inst. Water with the pitcher-plant, Sarracenia pur Resour. Rep. 26. purea L Can. J. Zool. 49:1455-1459. Richardson, C. J., D. L. Tilton, J. A. Pope, C. 1939. Turtles of the United Kadlec, J. P. M. Chamie, and W. A. States and Canada. Knopf, New York. Wentz. 1978. Nutrient dynamics of 343 pp. northern wetland ecosystems. Pages 217-241 in Freshwater Wetlands. Aca- Post, L. von. 1924. Das genetische Sys demic Press, New York. tem der organogenen Bildungen Schwedens. Comm. Int. Pedol. (Helsinki), Comm. Rigg, G. B. 1940. Comparison of the 22:287-304. development of some Sphagnum bogs of the Atlantic coast, the interior and the Post, L. von, and E. Granlund. 1926. Pacific coast. Am. J. Bot. 27:1-14. Sodra Sveriges torvtillganger. I. Sver iges Geol. Undersokn., Avh. and Upps., C 335:1-128. Robinson, A. G. 1972. A new species of aphid (Homoptera: Aphididae) from a pitcher plant. Can. Entomol. Pough, F. H. 1976. Acid precipitation 104:955-957. and embryonic mortality of spotted sala manders, Ambystoma maculatum. Science Rosswall, T., and U. Granhall. 1980. 192:68-70. Nitrogen cycling in a subarctic ombro trophic mire. Ecol. Bull. (Stockholm) Pough, F. H., and R. E. Wilson. 1976. 30:209-234. Acid precipitation and reproductive suc cess of Ambystoma salamanders. Pages Rycroft, D. w., D. J. A. Williams, and H. 531-544 in Proceedings International A. P. Ingram. 1975. The transmission Symposium-On Acid Rain and Forest Eco of water through peat. J. Ecol. system. 63:535-568. 93 eyarn, H., and A. J. S. Mcuonaid. 1985. Gov'2rnr.;ent Pr~iiting Office. Washington, Tolerance of S~ha~num to water level. D.C. 754 pp. J. Bryol. 13:57 -5 8.- Sorensen, E. R. 1986. The ecology and Rymal, D. E., a~d G. W. Folkerts. 1982. distribution of patterned fens in Maine Insects associated with pitcher plants and their relevance to the Critical (Sarracenia, Sarraceniaceae) and their Areas Program. Maine State Planning relationship to pitcher pla~t conserva Office, Planning Rep. 81. 159 pp. tion: a review. J. Ala. Acad. Sci. 53:131-151. Spear, R. N., Jr. 1976. Birds of Ver- mont. Green Mountain Audubon Society, Schwintzer, C. R. 1983. Wonsymbiotic and Burlington, Vt. B6 pp. symbiotic nitrogen fixation in a weakly minerotrophic peatland. Am. J. Bot. 70: Standen, V. 1979. Factors affecting the 1071-1078. distribution of lumbricids (Oligochaeta) in associations at peat and mineral Schwintzer, C. R., and T. J. Tomberlin. sites in northern England. Oecologia 1982. Chemical and physical character 42:359-374. i sties of shall ow ground waters in northern Michigan bogs, swamps and fens. Stockwell, S. S., and M. L. Hunter. 1985. Am. J. Bot. 69:1231-1239. Distribution and abundance of birds, amphibians and reptiles, and small mam Shaw, B. H., and L. Reinecke, eds. 1983. ma1 s in peatlands of central Maine. Chemistry and ecology of an acid bog Maine Department of Inland Fisheries receiving municipal waste water at Drum and Wildlife, Augusta. 89 pp. mond, Wisconsin. A summary of research 1978-1981. U.S. Fish and Wildlife Ser Stotler, R., and B. Crandall-Stotler. vice, Twin Cities, Minn. 196 pp. 1977. A checklist of the liverworts and (Mimeo.) thornworts of North America. Bryologist 80:405-428. Sjors, H. 1948. Myrvegetation i Bergsla gen. Acta Phytogeogr. Suec. 21: 1-299. Svendsen, J. A. 1957. The distribution of Lumbricidae in an area of Pennine Sjors, H. 1950. On the relation between moor 1and (Moore House Na tu re Reserve). vegetation and electrolytes in North J. Anim. Ecol. 26:411-421. Swedish mire waters. Oikos 2:241-258. Svensson, B. H., and T. Rosswall. 1980. Sjors, H. 1961. Surface patterns in Energy flow through the subarctic mire boreal peatland. Endeavour 20:217-224. at Stordalen. Ecol. Bull. (Stockholm) 30:283-301. Small. E. 1972. Ecological significance of four critical elements in plants of Swan, J. M. A., and A. M. Gill. 1970. raised S~hagnum peat bogs. Ecology The origins, spread, and consolidation 53:498-50 . of a floating bog in Harvard Pond, Petersham, Massachusetts. Ecology Small, E. 1973. Xeromorphy in plants as 51:829-840. a possible basis for migration between arid and nutritionally-deficient envi ronments. Bot. Not. 126:534-539. Tal 1 is, J. H. 1973. The terrestrializa tion of lake basins in North Cheshire Smith, J. B. 1902. Life history of Aedes with special reference to the develop smithii (Coq. ). J. N. Y. Entomol. SOC.- ment of "Schwingmoor" structure. J. 10:10-15. Ecol. 61:537-567. Soil Survey Staff. 1975. Soi 1 taxonomy. Tr?~dss?"• T. 1952. Den geologiska mil A basic system of soil classification J !'.?"S i 11yerk~n P3 •• grundvattnets ha 1t av for mak.fng and interpreting soil sur lQsta vaxtnaringsamnen. Kungl. Skogs veys. U.S. Oep. Agric. Hand. 436, U.S. hogsk. Skr. (Stockholm) 10. 16 pp. 94 Uhden, O. 195€. Neue Erkenntnisse uber Walker, E. M. 1958. The Odonata of Can das Sacken und Atmen der Hochmoore. ada and Alaska, II. University of Wasserwirtsch. 46:261-265. Toronto Press. 318 pp. Urban, N. R. 1983. The nitrogen cycle in Walker, E. M., and P. S. Corbet. 1975. a forested bog watershed in northern The Odonata of Canada and Alaska. III. Minnesota. M.S. Thesis. University of University of Toronto Press. 307 pp. Minnesota, Minneapolis. 359 pp. Warner, D.. and D. Wells. 1980. Bird Urban, N. R., S. J. Eisenreich, and E. population structure and seasonal habi Gorham. 1986. Proton cycling in tat use as indicators of environmental bogs:Geographic variation in northeast quality of peatlands. Minnesota Depart ern North America. In: T. c. Hutchison, ment of Natural Resources. 84 pp. ed. Effects of aciO-deposition on for ests, wetlands, and agricultural ecosys tems. (In press.) Waughman, G. J., and D. J. Bellall\Y. 1980. Nitrogen fixation and the nitrogen bal U.S./Canada Workgroup # 2. 1982. Atmos ance in peatland ecosystems. Ecology pheric Science and Analysis. Final Rep. 61 :1185-1198. (H. L. Ferguson and L. Machta, co-chair men). U.S. Environmental Protection White. H. B.• III, and W. J. Morse. 1973. Agency, Washington, D.C. Odonata (Dragonfiles) of New Hampshire: an annotated list. N. H. Agric. Exp. Verry, E. S. 1975. Stream flow chemistry Stn. Res. Rep. 30:1-46. and nutrient yields from upland-peatland watersheds in Minnesota. Ecology White, H. B., III .• and R. A. Raff. 1970. 56 :1149-1157. The nymph of Williamsonia lintneri (Hagen) [Odonata: Corduliidae]. Psyche Verry, E. S., and D. R. Tirrmons. 1982. 77:252-257. Waterborne nutrient flow through an upland-peatland watershed in Minnesota. Ecology 63:1456-1467. Wiegman, P. G. 1979. Rare and endangered vascular plant species in Pennsylvania. Vitt, D. H•• and S. Bayley. 1984. The Western Pennsylvania Conservancy in vegetation and water chemistry of four cooperation with U.S. Fish and Wildlife oligotrophic basin mires in northwestern Service. Newton Corner, Mass. 94 pp. Ontario. Can. J. Bot. 62:1485-1500. Worley, I. A. 1981. Maine peatlands, Walker, E. M. 1925. The North American their abundance, ecology and relevance dragonflies of the genus Somatochlora. to the Critical Areas Program. Maine University of Toronto Studies, Biol. Critical Areas Program Planning Rep. 73. Ser. 26:1-202. 387 pp. 95 APPENDIX: GLOSSARY OF TERMS Aapa mire - a type of soligenous peat1and, also called string mire, characterized by alternating strings and pools along the contours of the slope (Figures 1 and 9). Acrotelm - the zone of biologically active, aerobic or intermittently aerobic surface peat, through which almost all water movement takes place; the low water table is often used as the boundary with the catotelm (Figure 18). Aerobic - characterized by the presence of free oxygen. Anaerobic - characterized by the absence of free oxygen. Blanket bog - a type of ombrogenous peatland developing in climates with a large moisture surplus, such as cool, temperate, maritime climates; the peat covers slopes and valleys, but outcrops of mineral soil result locally in minerotrophic conditions. Bog - a nutrient-poor, acidic peatland with a moss layer dominated by Sphagnum mosses; ericaceous shrubs or conifers are often dominant. Bog pool - a small body of stagnant water in a bog, often several meters deep; in most peatlands they are secondary features. Capillary water - water drawn above the water table in the small pores of the soil; held more tightly than gravitational water, but available to plants. Capitulum - the head of a Sphagnum moss plant, formed by the dense growth of the newest branches. Catotelm - the zone of permanently anaerobic peat, characterized by neg- 1 igibl e water movement and very low biological activity (Figure 18). Convex domed bog - a type of raised ombrogenous peatland (Figure 1) with a gentle slope toward the center and a more gradual change from minerotrophic to ombrotrophic vegetation than in plateau bogs. Coprogenous sediment - a lake sediment consisting largely of fecal pellets of bottom fauna; relatively dark in color, slightly viscous but not sticky, and normally devoid of recognizable plant fragments. Detritus - dissolved and particulate dead organic matter. Dy - a brown lake sediment consisting largely of amorphous humus gels and mostly derived from bogs associated with the lake; poorer in nutri ents than gyttja. Endemic species - a species restricted to a region or habitat. Ericaceous - belonging to the heath family (Ericaceae). Eutrophic - relatively rich in nutrients; generally referring to a habi tat more nutrient-rich than oligotrophic or mesotrophic habitats. Evapotranspiration - combined loss of water from surface evaporation and from transpiration by plants. Fen - an open peatland, sometimes with scattered trees, occurring on min erotrophic sites; richer in nutrients and less acidic than a bog. Fen window - a site in a bog where nutrient-rich minerotrophic water reaches the surface. Fibrist - a suborder of organic soils (Histosols) characterized by a sub surface layer composed mainly of plant fibers, or by a surface layer 97 (top 60 cm) composed mainly of SEhagnum moss fiber~; less de composed than hemists or saprists. Graminoid - grass-like; referring to grasses, sedges ana rushes. Gyttja - a form of coprogenous sediment occurring in waters enriched in nutrients and oxygen, consisting of a mixture of particulate organic matter, inorganic precipitates, and minerogenic matter. Heath - an area in which the veqetation is dominated by ericaceous shrubs, growing on mineral or organic soil; used in Maine to refer to an erica- ceous dwarf-shrub bog. Hemist - a suborder of organic soils (Histosols) characterized by a sub surface layer dominated by mucky peat or peaty muck; more decomposed and generally more nutrient-rich than fibrists, but less than sa prists. Histosols - the soil order of organic soils. Hollow - a microtopographic depression of various sizes in peatlands; covered with Sphagnum moss, liverworts, lichens or bare peat, and intermittently with standing water. Humification - the process of decay of plant remains to amorphous organic matter. Hummock - a moss-covered elevation in a peatland, usually less than 40 cm high, and varying from less than 1 square meter to over 10 square meters in area, usually with dwarf shrubs, and sometimes with shrubs or trees. Hydrarch succession - the progression of con111unities occurring when a pond is transformed into a bog by filling and mat growth. Hydraulic conductivity - the rate at which water flows through a soil in response to a potential gradient. Hydrostatic pressure - the pressure required to stop the movement of water; used as a measure of water potential. Hypnoid mosses - mosses resembling those in the genus Hypnum, mostly used to indicate a variety of pleurocarpous mosses in peat- 1ands not dominated by Sphagnum. Lagg - the nutrient-enriched zone at the margin of a raised bog, receiving water from the surrounding mineral ground and from the bog itself. Limnogenous peatland - a type of mfnerotrophic peatland developing along a lake or slow-moving stream. Marsh - a wet area, periodically inundated with standing or slow-moving water, that has a grassy or herbaceous vegetation and often little peat accumulation; the water may be salt, brackish or fresh. Medifibrist - an organic soil great group belonging to the fibrist subor der, and distinguished from the sphagnofibrists by a surface layer that contains less Sphagnum fiber or is less thick. Mesotrophic - having moderate levels of nutrients; referring to a habitat intermediate in richness between eutrophic and oligotrophic. Meteoric water - atmospheric water, i.e. precipitation. Minerotrophic - areas influenced by water that has been in contact with soil or bedrock, and is richer in mineral-nutrient elements than rainwater. Mire - a general term for a variety of peatlands ranging from ombrotrophic bogs to fens and swamps. Mud-bottom - a flat depression or hollow in a bog, with a sparse cover of vascular plants and covered mostly by liverworts or with exposed peat. Obligate associates - species which always occur together. Obligate comnensals - a pair of species in which one species requires the other to survive, but in which the other species is not reduced in fitness. 01 igotrophic - poor to extremely poor in nutrients; referring to a habitat less nutrient-rich than eutrophic or mesotrophic. Ombrogenous peatland - a type of peatland in which development is con trol led by precipitation; ombrogenous peatlands are primarily om brotrophic but contain minerotrophic sites, mostly near their mar gins. Ombrotrophic - rain-fed; used mostly to indicate peatlands or portions of peatlands which receive water only from precipitation. Paludification - swamping of dry land by the rise of a water table in adjacent peatlands. Pattern - a repetitive micro-physiographic arrangement in a peatland; used mostly to refer to the pattern of strings and pools. Peat - the partially-decayed remains of plant material accumulating on wet sites because of water-logging. Peatland - a wet area in which peat has accumulated. Perched water table - a water table held above the regional level by an impermeable or slowly permeable layer. Plant community - an assemblage of plants interacting with one another and occupying, and often modifying, a habitat. Plateau bog - a type of raised ombrotrophic peatland characterized by a pronounced slope rising to an almost flat central plain; in the northeastern United States, this type of bog is restricted to the northeast coast of Maine (Figures 1 and 2). Quaking bog - a bog with a surface that quakes or yields under foot, and that rises and falls with water level changes, e.g., the mat of a floating bog. Raised bog - a type of ombrogenous peatland, with the ombrotrophic center raised above the minerotrophic bog border or lagg; this includes plateau and convex domed bogs. Saprist - a suborder of organic soils (Histosols) characterized by a subsurface layer dominated by muck, a black organic material composed of less than one-third identifiable fibers; more decomposed and more nutrient-rich than fibrists or hemists. Sapropel - a form of strongly reduced, biologically active, limnic peat. Sclerophyllous - having thick, leathery, and usually wintergreen leaves. Sedges - plant species in the sedge family (Cyperaceae), especially spe- cies of the genus Carex. Seepage - lateral water flow through the soil; it represents an impor tant mineral-soil water input into many peatlands. Slope fen - a type of soligenous peatland that develops on slopes; it can occur far south of the zone of aapa mires if the supply of seepage water is abundant. Soligenous peatland - a type of minerotrophic peatland depending on a reliable source of seepage water; water seeps through or over the surface peat. Sphagnofibrist: an organic soil great group belonging to the fibrist suborder, and having a surface layer that consists of 75% or more of material derived from Sphagnum mosses, and being either 90 cm or more thick, or rests on rock or mineral soil . . Stratigraphy - the vertical sequence of layers of peat and other materials as deposited by vegetation in situ; this sequence records the his- tory of the depositional environment and may be used to trace the development of the peatland. String - narrow, elevated ridges oriented with their long axes across the slope and alternating with elongated pools. . Swamp - a wet minerotrophic peatland in which standing or gently flowing water occurs seasonally or persists for long periods, e.g., wooded swamps and shrub swamps. 99 Telluric water - terrestrial water: water that has been in contact with the mineral soil or bedrock. - Topogenous peatland - a type of minerotrophic peatland developing in topo graphical positions where water accumulates; generally maintained by a permanent ground water table. Wooded heath - an ericaceous dwarf-shrub bog with some tree cover; heath and wooded heath are used in this sense only in Maine. Wooded swamp - a wet minerotrophic peatland with sparse to dense tree co ver; the trees are rooted below mean water level and can tolerate large water-level fluctuations. 100 snn·tf! ...... _.. R£POll'T DOCUMENTATION Ill'°'"' "'°· I. __ PAGE IL Biological Report 85(7.16) .. ,__....._ .. ..._. 0- The Ecology of Peat Bogs of the Glaciated Northeastern July 1987 United States: A Community Profile ... 1• .--c., ...... ~.._.~ Antoni W. H. Damman 1 and Thomas w. French2 10...... ,,.__ """_ ...... ~..._-Add ..... Authors' Affiliation: 1 0epartment of Ecology and 2 Division of Fisheries Evolutionary Biology and Wildlife n. ~ .. Gnnt(O) ;;;:----- The University of Connecticut Commonwealth of Massachusetts (C) Storrs, CT 06268 Boston, MA 02202 (GJ U. 9-Mn,. Orpn-loft Heme end --• u. s. Department of the Interior 11. Ty0et1~&-C-f'H Fish and Wildlife Service National Wetlands Research Center Washington, DC 20240 1•. II. S..Pt>lement•rv -- I.._ Abtltract (Umlt: 200 -rdal The publication reviews the ecological information available for peat bogs in the glaciated Northeastern United States, a region extending from the Canadian border to the Pocono Mountain area of Pennsylvania. Peat bogs depend on acidic, nutrient-poor water for development and usually occur in areas underlain by sand, grave 1, or glacial ti 11. The hydro logic characteristics and chemical composition of bogs influences both nutrient cycling and plant community development within bogs. This pub l i cation describes peat bogs, their distribution in the area under consideration, the physical settings in which they exist, and the types of bogs generally recognized. Hydrology, water chemistry, and Thie; rli .. ru .. -.i0n the eye Ii ng ol nutrienb dlH.J ot!Hel' eleme11b in peJt bogs .:ire discus!:ed leads into two chapters describing the vegetation and animal communities of peat bogs. The final chapters discuss anthropogenic influences on peat bogs and recommend studies to fi 11 the gaps in our present understanding of the ecology of the peat bogs. 11. --""81\'91• •. OffcrlPCDr8 Wetlands Vertebrates Peat bogs Northeastern USA Plants .. -flerw/()pen·End c. COSA TI f'leld/lilroup lt. S.CUnty Cla•• Blueberry) ---. ------Rhododendron ...-iscosum {Swamp Honey5uckle) ------Pyru.s arburifoli.a (Red Chokeberry) --~ A/nus serru/ata (Smooth Alder) Sb A/nus wgosa (Spe.::kled Alder) Nemopanthus mucronata (Mountain-Holly) --~ Becula ;Jopulifolia (Gray Birch) Viburnum cassillOide:s (Wnld-Raisin)