Circumpolar Vegetation

Barrens Prostrate- Finland Sweden o 0 Iceland B1. Cryptogam, P1. Prostrate dwarf- herb barren shrub, herb Dry to wet barren Dry tundra with patchy landscapes with very B1 vegetation. Prostrate P1 sparse, very low-growing North Atlantic Ocean < 5 cm tall (such as plant cover. Scattered Dryas and Salix arctica) herbs, , , and are dominant, with liverworts. Subzone A and B, graminoids and forbs. some C at higher elevations. Lichens are also common. Eskimonaesset, North , C. Bay Bunde Fjord, Axel Heiberg Island, Canada. D.A. Walker Bunde Fjord,

45 o Subzones B and C. o W Russia E 45 B2. Cryptogam barren P2. Prostrate/ complex (bedrock) Hemiprostrate Areas of exposed rock and dwarf-shrub tundra lichens interspersed with B2 Moist to dry tundra lakes and more vegetated P2 dominated by prostrate areas, as found on the and hemiprostrate shrubs Canadian Shield. Subzones Barents Pechora R. Greenland < 15 cm tall, particularly C and D. Sea Canada Cassiope. Subzone C. Daring Lake vicinity, Canada. D.A. Walker Daring Lake vicinity,

Svalbard Zackenberg, East Greenland, H.H. Christiansen Baffi n B3. Noncarbonate Island B3a mountain complex B3b Mountain vegetation on Erect-shrub tundras Ob R. noncarbonate bedrock. The S1. Erect dwarf- B3c variety and size of decrease with elevation and shrub tundra B3d latitude. Hatching color and Tundra dominated by erect code indicate the bioclimate dwarf-shrubs, mostly < 40 Novaya S1 B3e subzone at the mountain cm tall. Subzone D. base. B3a through B3e Daniëls Qingertivaq Fjord, SE Greenland. F.J.A. Zemlya Baffi n Bay B3n indicate subzones A through E; B3n indicates noncarbonate nunatak Daring Lake, Canada. D.A. Walker areas. For more explanation Franz Josef see reverse side. S2. Low-shrub Land tundra B4. Carbonate Tundra dominated by B4b Kara low shrubs > 40 cm tall. mountain complex Hudson Bay S2 Sea Subzone E. B4c Mountain vegetation on carbonate bedrock. The B4d variety and size of plants decrease with elevation and Yenisey R. B4e latitude. Hatching color and Ellesmere Alaska. D.A. Walker Seward Peninsula, code indicate the bioclimate o Island 90 E 90o W B4n subzone at the mountain

Brooks Range, Alaska. D.A. Walker Brooks Range, Wetlands base. B4b through B4e indicate subzones B through E; B4n indicates W1. Sedge/grass, Severnaya carbonate nunatak areas. wetland

For more explanation see Zemlya R. Wetland complexes in the

son reverse side. l colder areas of the Arctic, W1

Ne dominated by sedges, grasses, and mosses. Graminoid tundras Subzones B and C. Arctic Ocean Canada

G1. Rush/grass, forb, Russia Resolute, Cornwallis Island, Canada. D.A. Walker cryptogam tundra Moist tundra with W2. Sedge, moss, dwarf-shrub wetland G1 moderate to complete cover of very low-growing Wetland complexes in the plants. Mostly grasses, milder areas of the Arctic, Lake W2 rushes, forbs, mosses, Victoria dominated by sedges, lichens, and liverworts. Island grasses, and mosses, but Subzones A and B. including dwarf shrubs < 40 Amund Ringnes Island, Canada. D.A. Walker o N cm tall. Subzone D. A r 80 Lake ctic Banks New Siberian Island Athabasca Alaska. D.A. Walker North Slope coastal plain, Cir Islands Great Slave W3. Sedge, moss, G2. Graminoid, c Lake le Slave R. low-shrub wetland prostrate dwarf-shrub, Lena R. forb tundra Great Bear Wetland complexes in the Lake warmer areas of the Arctic, W3 Moist to dry tundra, a R. G2 c s dominated by sedges and with open to continuous

Vi aba low shrubs > 40 cm tall. cover. Sedges are h ly t

uy A Subzone E. dominant, along with R. M prostrate shrubs < 5 cm ackenzie R.

tall. Subzone C, some B. Talbot Alaska. S.S. Delta, Yukon-Kuskokwim Eureka vicinity, Ellesmere Island, Canada. D.A. Walker Eureka vicinity, East Siberian Beaufort Sea Sea 135 Liar o d R. G3. Nontussock W Circumpolar Arctic Vegetation Map sedge, dwarf-shrub, Ald CAVM Mapping Team: moss tundra en R. Canada: William A. Gould, Lawrence C. Bliss, Sylvia A. Edlund, o E Canada Moist tundra dominated by Lena R. Martha K. Raynolds, Stephen C. Zoltai Greenland: Fred J. A. Daniëls, Christian Bay, Maike Wilhelm G3 135 Glossary sedges and dwarf shrubs Wrangel Iceland: Eythór Einarsson, Gudmundur Gundjónsson < 40 cm tall, with well- Arctic bioclimate zone: The region of this map; the bioclimate Herb: A fl owering plant with no signifi cant woody tissue above Norway/Svalbard: Arve Elvebakk, Bernt E. Johansen Island zone north of the climatic limit of trees that is characterized by ground. Herbaceous plants include forbs and graminoids. Russia: Galina V. Ananjeva, Dmitry S. Drozdov, Adrian E. Katenin, developed moss layer. an Arctic climate, Arctic fl ora, and tundra vegetation. It includes Nunatak: A nonglaciated area surrounded by glaciers, often a Sergei S. Kholod, Lyudmila A. Konchenko, Yuri V. Korostelev, Evgeny S. Melnikov, Natalia G. Moskalenko, Alexei N. Polezhaev, Olga E. Ponomareva, Barren patches due to all the arctic tundra regions with an Arctic climate and Arctic mountain peak taller than the surrounding glaciers. fl ora, but it excludes tundra regions that have a boreal fl ora such Elena B. Pospelova, Irina N. Safronova, Raisa P. Shelkunova, Boris A. Yurtsev frost boils and periglacial Kolyma R. Chukchi United States/Alaska: Martha K. Raynolds, Michael D. Fleming, Carl J. Markon,

Ambarchik, Yakutia, Russia, D.A. Walker Ambarchik, Yakutia, as the boreal oceanic areas of Iceland and the Aleutian Islands, Physiognomy: The general outward appearance of a plant features are common. Sea and alpine tundra regions south of the latitudinal treeline. community, determined by the life forms of the dominant species, David F. Murray, Stephen S. Talbot, Donald A. Walker e.g., grassland, forest, tundra. Subzones D and C, some E. About the CAVM Bioclimate zone: A region of the Earth’s surface with Project Director: characteristic climate, fl ora, and vegetation. Bioclimate subzones Plant functional type: A category of plants based on factors Donald A. Walker The Circumpolar Arctic Vegetation Map (CAVM) shows the types of vegetation that occur are subdivisions based on a combination of fl oristic composition, such as growth form, size and taxonomic status. The tundra plant Compilation and Cartography by: Produced by: functional types used in the map-unit names include graminoids, G4. Tussock-sedge, across the Arctic, between the ice-covered Arctic Ocean to the north and the northern limit of dominant plant community structure (physiognomy), and the Martha K. Raynolds and Hilmar A. Maier Natalie G. Trahan (Johnson Controls Inc.), suite of plant communities in common habitats (See Table 1, forbs, shrubs of various stature, and cryptogams (mosses and Alaska Geobotany Center Tammy M. Charron, forests to the south. Environmental and climatic conditions are extreme, with a short growing on R. dwarf-shrub, moss United reverse side). The bioclimate subzones used here are adopted with lichens). (See these categories for further explanation.) Institute of Arctic Biology Beth A.Vairin, Susan M. Lauritzen Yuk tundra season and low summer temperatures. The region supports plants such as dwarf shrubs, herbs, States modifi cation from the phytogeographic subzones of Yurtsev (1994) Riparian: An intrazonal habitat pertaining to streamside University of Alaska Fairbanks USGS National Wetlands Research Center Fairbanks, Alaska 99775 USA 700 Cajundome Blvd. Moist tundra, dominated lichens and mosses, which grow close to the ground. As one moves southward (outward from and the bioclimate zones of the Panarctic Flora Initiative (Elvebakk environments. G4 et al. 1999). Lafayette, Louisiana 70506 USA by tussock cottongrass map’s center in all directions), the amount of warmth available for plant growth increases Shrub: A woody perennial plant differing from a tree by its lower Carbonate: Refers to limestone or dolomite bedrock. These stature and by producing several basal stems instead of a single Funded by: considerably. Warmer summer temperatures cause the size, abundance, and variety of plants U.S. National Science Foundation grant number OPP-9908-829, U.S. Fish and Wildlife (Eriophorum vaginatum) . bedrock types result in soils with high calcium content, trunk. This group includes: tall shrub, greater than 2 m tall (e.g., Service, U.S. Geological Survey, U.S. Bureau of Land Management. and dwarf shrubs <40 cm to increase. Climate and other environmental controls, such as landscape, topography, soil dyr R high pH, and plant communities adapted to such conditions. Alnus crispus, Salix alaxensis); low shrub, between 0.4 and 2 Ana tall. Mosses are abundant. chemistry, soil moisture, and the available plants that historically colonized an area, also Noncarbonate refers to sandstone, granite, or other rock types m tall (e.g., Betula glandulosa, ); and dwarf shrub, Suggested Citation: with few carbonates. less than 0.4 m tall. Dwarf shrubs are further divided into erect CAVM Team. 2003. Circumpolar Arctic Vegetation Map. Scale 1:7,500,000. Subzone E, some D. infl uence the distribution of plant communities. dwarf shrub, less than 0.4 m tall with erect stems (e.g., Vaccinium Conservation of Arctic Flora and Fauna (CAFF) Map No. 1. U.S. Fish and Wildlife Imnavait Creek, Alaska. D. A. Walker Cryptogam: A plant that reproduces sexually without forming uliginosum, Ledum decumbens, Betula nana); hemiprostrate Service, Anchorage, Alaska. The colors on the map indicate the differences that occur in the general outward appearance seeds. This group includes many common tundra ground plants, dwarf shrub, very short, generally less than 0.15 m tall, with of vegetation (physiognomy). The CAVM team grouped over 400 described plant Gulf of such as lichens, symbiotic associations of algae and fungi, and a semi-erect or trailing stem (refers here mainly to Cassiope Web sites: www.geobotany.uaf.edu, www.caff.is Glaciers mosses, members of the class Musci. tetragona); prostrate dwarf shrub, lying fl at on the ground (e.g., communities into 15 physiognomic units based on plant growth forms. The insert diagram Alaska Dryas, Arctous rubra, Salix arctica). (upper left) shows the relationship between the map units (except for B2, B3, and B4, which Bering Sea Forb: A broadleaf herbaceous (nonwoody) fl owering plant. Does not include graminoids. Tundra: A physiognomic descriptor of low-growing vegetation are barren rock or mountain complexes), and the principal environmental controls, summer beyond the cold limit of tree growth, both at high elevation (alpine Graminoid: A grass-like herbaceous plant with mostly tundra) and at high latitude (arctic tundra). Tundra vegetation types temperatures and site moisture. The total area of each map unit (in square kilometers) is o Riparian corridors - Complexes with mix of vegetation from bare gravel bars to 180 very narrow or linear in outline. This group includes grasses, are composed of herbaceous plants, shrubs, mosses, and lichens. fully vegetated areas. Characteristic plants range from herbs and cryptogams (Subzones summarized in the bar chart (upper right). members of the plant family Poaeceae; rushes, members of A and B) to dense tall shrubs (Subzone E). the plant family Juncaceae; and sedges, members of the plant Wetland: An intrazonal habitat where soil water saturation is the An international team of arctic vegetation scientists representing the six countries of the family . Sedges are further divided into tussock dominant factor determining the nature of soil development and vegetation. Water sedges, those with a caespitose or bunch-forming habit (refers Arctic—Canada, Greenland, Iceland, Norway, Russia, and the United States—prepared the 0 100 200 300 400 500 km here mainly to Eriophorum vaginatum), and nontussock sedges, Zonal vegetation: Vegetation within a specifi ed bioclimate zone map. The methods used to create the map, more detailed descriptions of the map units, and those with other growth forms, usually growing from , that ultimately develops on sites with moderate slope, soil, snow, Non-Arctic areas additional maps and information are on the reverse side. Lambert Azimuthal Equal-Area Projection stolons, or singly. site moisture, and disturbance. Scale 1:7,500,000 Detailed Vegetation Descriptions Note: Syntaxa (formal vegetation units) follow the Braun-Blanquet nomenclature system (Weber et al. 2000, Westhoff and Van der Maarel 1973) and are recog- Bioclimate Zonation nized worldwide by the International Botanical Congress. Barrens with ice-rich permafrost and shallow active layers, e.g., northern Making the Circumpolar Arctic Vegetation Map As one moves from north to south about 7-9˚C), and low shrubs (40-200 cm Table 1. Vegetation properties in each bioclimate subzone Alaska and Chukotka. Plant cover is nearly continuous (80-100%). across the Arctic, the amount of warmth tall) in Subzone E (mean July temperature B1B1 The height of the plant canopy varies from about 20 cm to 40 cm. A less robust form of tussock tundra grows in Subzone D, with smaller available for plant growth increases. about 9-12˚C). At treeline, where the B1. Cryptogam, herb barren tussock sedges and less abundant and shorter shrubs that do no overtop The idea of the Circumpolar Arctic Vegetation Map (CAVM) originated at the Arctic The mean July temperatures are near mean July temperatures are between Dry to wet barren desert-like landscapes mainly in Subzone A and the tussocks. Vegetation Classifi cation Workshop in Boulder, Colorado, in 1992 (Walker et al. 1995). 0˚C on the northernmost islands. At 10 and 12˚C, woody shrubs up to 2 m on some coarse-grained, often calcareous sediments in subzones B Dominant plants: Tussock sedges (Eriophorum vaginatum, Carex A map of arctic vegetation with a unifi ed legend was needed for global and regional and C. Sparse (2-40%) horizontal plant cover, and very low vertical lugens) with other sedges (Carex bigelowii/arctisibirica/consimilis, these temperatures, plants are at their tall are abundant. The number of plants structure (generally <2 cm tall) with a single layer of plants where they Eriophorum triste), and prostrate and erect dwarf-shrubs (Ledum computer models of climate change, land-use planning, conservation studies, resource metabolic limits, and small differences in local fl oras available to form plant occur. Dry herb barrens composed of few scattered vascular plants decumbens, Betula nana/exilis, Salix pulchra, Vaccinium vitis-idaea, V. development, and education. Scientists from Russia, Norway, Iceland, Greenland, are present over much of the landscape. Snow-fl ush communities are uliginosum ssp. microphyllum, Arctous alpina, Rubus chamaemorus, R. AVHRR base map in the total amount of summer warmth communities increases from fewer than 50 often a conspicuous component, forming dark streaks on the otherwise arcticus, Cornus suecica), and mosses (Sphagnum, Hylocomium splen- Canada and the United States (see other side) collaborated on the map (Walker et al. make large differences in the amount of species in the coldest parts of the Arctic barren lands, composed largely of bryophytes and cryptogamic crusts. dens, Oncophorus wahlenbergii, turgidum, Dicranum, 2002). In upland areas, cover is generally very sparse (<2%), Polytrichum). Other common plants include grasses (Arctagrostis energy available for maintenance, growth, to as many as 500 species near treeline. A mainly scattered individual plants often in crevices between stones or latifolia), forbs (Pedicularis lapponica, P. labradorica, Bistorta and reproduction. Warmer summer fundamental problem in creating the map small (< 50 cm diameter) cryoturbated polygons. Sedges (Cyperaceae), plumosa, P. tripterocarpum, Saxifraga nelsoniana, Nardosmia frigida), The map on the front side portrays the dominant vegetation physiognomy, the general temperatures cause the size, horizontal was how to characterize the transitions in dwarf shrubs, and peaty mires are normally absent. and lichens (Flavocetraria, Cladina rangiferina, Cladonia amauro- appearance of the vegetation based on the dominant plant growth forms. A false color- Dominant plants:The most common vascular plants are cushion forbs craea, Ochrolechia frigida, Alectoria nigricans, Bryocaulon diver- cover, abundance, productivity, and vegetation that occur across the roughly a (Papaver dahlianum ssp. polare, Draba, Potentilla hyparctica , gens). infrared (CIR) image of Advanced Very High Resolution Radiometer (AVHRR) data n variety of plants to increase (Table 1). 10˚C difference in mean July temperature. Saxifraga oppositifolia ) and graminoids (Alopecurus alpinus, Representative syntaxa: Sphagno-Eriophoretum vaginati Walk. et al. (at right) was used as a base map for drawing map polygons on a 1:4 million-scale Deschampsia borealis/brevifolia, Poa abbreviata, Puccinellia angus- 1994 (Alaska); Carici arctisibiricae-Hylocomietum alaskani vicariant Woody plants and sedges are absent in Different geobotanical traditions have a a Lambert’s azimuthal equal area projection. The image is composed of 1 x 1-km picture tata, Phippsia , Luzula nivalis , L. confusa ), lichens (Caloplaca, of Pinguicula villosa Matv. 1994 (Taimyr Peninsula) (cf. Ledo decum- Subzone A, where mean July temperatures divided the Arctic into bioclimatic regions Lecanora, Ochrolechia, Pertusaria, Mycobilimbia, Collema, Tham- bentis-Betuletalia glandulosae Rivas-Martinez et al. 1999). elements (pixels). The color of each pixel was determined by its refl ectance at the time nolia, Cetraria, Flavocetraria, Cetrariella, Stereocaulon), mosses are less than 3˚C. Woody plants fi rst occur using a variety of terminologies (Table n n n of maximum greenness, selected from biweekly images from 1 April to 31 October (Racomitrium, Schistidium, Orthothecium , Ditrichum , Distichium , Prostrate-shrub tundras in Subzone B (mean July temperatures 2). The origins of these different terms Encalypta, Pohlia, Bryum, Polytrichum), liverworts (e.g., Gymnomi- in 1993 and 1995. These periods cover the vegetation green-up-to-senescence period about 3-5˚ C) as prostrate (creeping) and approaches have been reviewed for trion, Cephaloziella), and cyanobacteria. P1 during two relatively warm years when summer-snow cover was at a minimum in the Representative syntaxa: Communities of the classes Thlaspietea dwarf shrubs, and increase in stature to the Panarctic Flora (PAF) Initiative. The rotundifolii Br.-Bl. et al. 1947 (e.g., Papaveretum dahliani Hofm. P1. Prostrate dwarf-shrub, herb tundra Arctic. The resulting image shows the Arctic with minimum snow and cloud cover. hemiprostrate dwarf shrubs (<15 cm tall) PAF and CAVM have accepted the fi ve- 1968) and Salicetea herbaceae Br.-Bl. et al. 1947 (e.g., Phippsietum Dry tundra of the Middle Arctic (sensu Polunin 1951; polar semides- Reddish areas represent greater amounts of green vegetation; blue and gray areas in Subzone C (mean July temperatures subzone approach used here (Elvebakk et algidae-concinnae Nordh. 1943). erts of Bliss 1997). This is the zonal vegetation of Subzone B and also represent sparse vegetation; black areas represent fresh water, and white areas represent covers large dry areas in Subzone C. The vegetation is open or patchy about 5-7˚C), erect dwarf shrubs (<40 cm al. 1999). B2 (20-80% cover), with plants 5-10 cm tall. Vascular plants cover about ice. Most boundaries on the vegetation map correspond to features that can be seen on tall) in Subzone D (mean July temperature 5-25%, lichens and mosses cover 30-60%. On nonacidic substrates of the image when it is enlarged to 1:4 million scale. The image data were obtained from B2. Cryptogam barren complex (bedrock) Subzone B the dominant zonal vegetation is Dryas - Salix arctica com- Bedrock covered with lichens, usually mixed with many lakes and the munities; on acidic substrates it is Luzula - Salix arctica. the USGS Alaska Geographic Science Offi ce. Glaciers and oceans were masked out by zonal vegetation. The largest areas are on Precambrian granite and Dominant plants: Prostrate dwarf-shrubs (Dryasn, Salix arctica, S. using information from the Digital Chart of the World (ESRI 1993). Bioclimate subzones gneiss bedrock of the Canadian Shield, but also in the high elevation polaris, S. rotundifolia, S. phlebophyllaa) are dominant. Other common areas of Siberia, northeast , Alaska, and Greenland, which are plants include sedges (Eriophorum triste, Carex rupestrisn), rushes mapped as part of the mountain complex (Units B3 and B4). Areas (Luzula confusaa, L. nivalisa, Juncus biglumis), grasses (Alopecurus Key environmental and biological factors control the plant communities that can between bedrock outcrops commonly have dwarf shrubs and fruticose a alpinus (Subzone B), Deschampsia), forbs, (Saxifraga hirculus, S. 1 Based on Edlund (1990) and Matveyeva (1998). lichens. Found in Subzones C and D. grow across the Arctic. The most important environmental control in the Arctic is caespitosaa, S. oppositifolian, Novosieversia glacialisn, Oxytropisn), 2 Sum of mean monthly temperatures greater than 0˚C, modifi ed from Young (1971). Dominant plants: Saxicolous lichens (Lecidia, Lecanora, Buellia, n n summer temperature. Temperature data and vegetation data together defi ne bioclimatic mosses (Ditrichum fl exicaule , Distichium , Sanionia uncinata, Enca- 3 Chernov and Matveyeva (1997). Porpidia, Rhizocarpon, Umbilicaria, Parmelia, Xanthorian, Calopla- lypta, Pohlia, Polytrichum, Hylocomium splendens, Aulacomnium subzones (see Bioclimate subzone map). Topographic information (see Elevation map) 4 b - barren; c - cryptogam; cf - cushion or rosette forb; deds - deciduous erect dwarf shrub; dls - deciduous low shrub; dpds - deciduous prostrate dwarf shrub; g - grass; ehds - evergreen hemiprostrate dwarf shrub; nb - nonsphagnoid bryophyte; can, Aspicilian) cover the rock surfaces. Betula, Ledum palustre ssp. turgidum, Tomentypnum nitensn), and lichens (Thamnolia, Flavoce- neds - nondeciduous erect dwarf shrub; npds - nondeciduous prostrate dwarf shrub; ns - nontussock sedge; of - other forb; ol - other ; r - rush; rl - reindeer lichen; sb - sphagnoid bryophyte; ts - tussock sedge. Underlined codes are dominant. decumbens, Arctous alpina, Cassiope tetragona, Vaccinium, the grass and landscape maps were used to defi ne landscape units (see Landscape map). Lake 5 Based on Bazilevich et al. (1997), aboveground + belowground, live + dead. traria). In Subzone C this vegetation is much richer in vascular spe- Hierochloë alpina, and terricolous lichens (Cladonia, Cladina, 6 Based on Bazilevich et al. (1997), aboveground + belowground. cies, particularly sedges, grasses, and forbs. cover was calculated from the AVHRR image (see Lake cover map). Bedrock geology Flavocetraria, Masonhalea richardsonii, Stereocaulon, Bryocaulon 7 Number of vascular species in local fl oras based mainly on Young (1971). Representative syntaxa: Communities of the class Carici-Kobresie- divergens, Alectoria ochroleuca) grow between the bedrock outcrops. and surface geology were used to determine the general chemistry of the substrate on tea, e.g., Carici-Dryadetum integrifoliae Dan. 1982 (Greenland, North Representative syntaxa: Communities of the class Rhizocarpetea America), and Loiseleurio-Vaccinietea, e.g., Gymnomitrio-Loiseleuri- which plant communities grow (see Substrate pH map). East-west variations in species Table 2. Other bioclimate zonation approaches geographici Wirth 1980 (Canada, on granite bedrock). etum Dan. 1982 (Greenland). distribution were defi ned by fl oristic provinces (see Floristic provinces map). Plant B3a B3b B3c B3d B3e B3n P2 biomass was estimated from the normalized difference vegetation index (NDVI) (see Aboveground plant biomass map). All of these factors were combined to determine B3. Noncarbonate mountain complex P2. Prostrate/hemiprostrate dwarf-shrub tundra Dry acidic tundra complexes on mountains and plateaus with noncar- the type of vegetation found in a polygon. The map polygon boundaries combine the Moist to dry tundra in acidic-bedrock portions of Subzone C where bonate bedrock. Vegetation changes with elevation in the mountains, hemiprostrate dwarf-shrub (Cassiope tetragona) communities occupy terrain information and follow features visible on the 1:4 million AVHRR base image. forming elevation belts whose vegetation is physiognomically similar a large portion of the landscape. In nonacidic areas Cassiope commu- to that of bioclimate subzones with comparable summer climate (see The polygons have a minimum size of 14 km diameter (8 km for linear features). nities occur in sites with somewhat deeper than average winter snow Figure 2). The color of the polygon hatch pattern denotes the biocli- cover. In acidic areas, Cassiope communities are dominant on zonal mate subzone at the base of the mountains. For example B3a occurs in sites. This type is common on granite- and gneiss-bedrock of Svalbard, Subzone A, B3b in Subzone B, etc. B3n denotes nunatak areas, with Polygons at this scale contain many vegetation types. Common dry, moist, wet, Greenland, Baffi n Island, and Ellesmere Island. Plants cover 40 to many noncarbonate mountain peaks surrounded by glaciers. Mesic snowbed and riparian plant communities (Figure 1) were described for each bioclimatic 100% of the surface. The height of the plant canopy is 10-20 cm. zonal microsites are relatively uncommon. More common are plant Dominant plants: Prostrate and hemiprostrate dwarf shrubs subzone and fl oristic region. Generally, the dominant zonal vegetation was mapped. communities growing on wind-swept, rocky ridges, screes, and dry (Cassiope tetragona, Dryasn, Rhododendron lapponicumn, Zonal sites are areas where the vegetation develops under the prevailing climate, fell-fi elds, alternating with snowbed plant communities. Salix arctica, S. polaris) and mosses (Aulacomnium turgidum, Representative syntaxa for each elevation belt: Belt a in Subzone B, Tomentypnum nitensn, Hylocomium splendens, Sanionia uncinata, uninfl uenced by extremes of soil moisture, snow, soil chemistry, or disturbance. cf. Papaveretum dahliani Hofm. 1968, in subzones C-E Papaveretum a a Color representations described in text at left. Polytrichum juniperinum), rushes (Luzula confusa , L. nivalis ), Zonal sites are fl at or gently sloping, moderately drained, with fi ne-grained soils. The Subzone A radicatae Dierss. 1992 (both Thlaspietea rotundifolii); Belt b, forbs (Oxyria digyna, Bistorta vivipara, Silene acaulis) and Carici-Dryadetum integrifoliae Dan. 1982 (Carici-Kobresietea Ohba vegetation of extensive nonzonal areas such as mountain ranges, large wetlands, and lichens (Peltigera aphthosa, Cetrariella deliseii, Stereocaulon Subzone B 1974); Elevation Belt c, e.g., Cassiopetum tetragonae (Böch. 1933) rivulorum, Solorina, and Thamnolia). river systems was also mapped. Dan. 1982 (Loiseleurio-Vaccinietea Eggl. 1952 em. Schub. 1960); Representative syntaxa: Communities of the class Loiseleurio- Belt d, Empetrum-Vaccinium community Dan. 1982 or Empetro-Betu- Subzone C Vaccinietea, e.g., Cassiopetum tetragonae (Böch. 1933) Dan. 1982 letum nanae Nordh. 1943, and Belt e, Betulo-Salicetum glaucae prov. (Greenland, noncarbonate soil) and Carici-Kobresietea, e.g., Dryado- Subzone D Dan. 2002 (all Loiseleurio-Vaccinietea) (Greenland). Cassiopetum tetragonae (Fries 1913) Hadac 1946 (Svalbard). Subzone E B4b B4c B4d B4e B4n Erect-shrub tundras B4. Carbonate mountain complex Dry calcareous tundra complexes on mountains and plateaus with lime- S1 stone or dolomite bedrock. Vegetation changes with elevation in the Topography mountains, forming elevation belts whose vegetation is physiognomi- S1. Erect dwarf-shrub tundra cally similar to that of bioclimate subzones with comparable summer Moist to dry tundra in Subzone D on acidic soils, dominated by climate (see Figure 2). The color of the polygon hatch pattern denotes hemiprostrate and erect dwarf shrubs less than 40 cm tall. This is the zonal vegetation in acidic and oceanic areas of Subzone D in the bioclimate subzone at the base of the mountains. For example, B4b Elevation occurs in Subzone B, B4c in Subzone C, etc. B4n denotes nunatak Greenland and the Canadian Shield. Drier, lichen-rich dwarf-shrub Substrate Chemistry areas, with many carbonate mountain peaks surrounded by glaciers. tundras are common in many areas, e.g., the sandy soils of the Yamal Mesic zonal microsites are relatively uncommon. More common are and Gydan peninsulas in Russia, and in a matrix with lichen-covered Floristic Variation plant communities growing on wind-swept, rocky ridges, screes, and bedrock on the Canadian mainland and Baffi n Island. Plant cover is dry fell-fi elds, alternating with snowbed plant communities. continuous (80-100%) on zonal sites to sparse (5-50%) on dry ridges. Differences in substrate Representative syntaxa for each elevation belt: Belt a, Thlaspietea Dominant plants: Dwarf-shrubs (Betula nana/exilis, B. glandulosa, Substrate pH Vaccinium uliginosum ssp. microphyllum, V. vitis-idaea, Ledum palus- chemistry have important The Arctic has a relatively rotundifolii vegetation, e.g., Papaveretum dahliani Hofm. 1968; Belt b, Floristic provinces Carici-Dryadetum integrifoliae Dan. 1982; Belt c, Carici-Dryadetum tre spp. decumbens, Empetrum, Salix glauca, S. callicarpaea, Arctous, effects on dominant plant consistent core of plant Cassiope tetragona). Mosses (Hylocomium splendens, Aulacomnium integrifoliae Dan. 1982; Belt d, Dryado integrifoliae-Caricetum communities. Some of the most species that occur around the bigelowii Walk. et al. 1994 (all Carici-Kobresietea); Belt e, cf. turgidum, Dicranum, Racomitrium lanuginosum) and lichens Anemono-Salicetum richardsonii Schickh. et al. 2002 (most of North- (Stereocaulon, Cladonia, Flavocetraria, Alectoria ochroleuca, important effects are related circumpolar region, but there is ern America). Masonhalea richardsonii, Bryocaulon divergens) are common. to soil pH, which governs Representative syntaxa: Communities of the class Loiseleurio- also considerable east to west the availability of essential Graminoid tundras Vaccinietea, Phyllodoco-Vaccinion myrtilli Nordh. 1936, e.g., variation in the regional fl oras, Phyllodoco-Salicetum callicarpaeae (Böch. 1933) Dan. 1982 and plant nutrients. Soils in the particularly in subzones C, D, Empetrum-Vaccinium community Dan. 1982 (Greenland). G1 circumneutral range (pH 5.5- and E. This variation is due to G1. Rush/grass, forb, cryptogam tundra S2 7.2) are generally mineral a number of factors, including Moist tundra on fi ne-grained, often hummocky soils in subzones A and S2. Low-shrub tundra rich, whereas the full suite different histories related to B. Plant cover is moderate (40-80%), and the vegetation forms a single Moist tundra in Subzone E dominated by low shrubs greater than 40 Figure 1. Local topography of essential nutrients is often layer generally 5-10 cm tall. This is the zonal vegetation in Subzone A, glaciations, land bridges, and cm tall sometimes on permafrost-free soils. Peatlands with permafrost Small-scale variations in topography determine the patterns of plant communities that exist within each polygon, though often occurring in somewhat more protected areas with moderate snow unavailable in acidic soils (pH are common in wet areas. This highly variable unit includes some areas north-south trending mountain cover. Except for the greater density of plants, particularly rushes and these fi ne-scale patterns are too small to portray on the map. This idealized mesotopographic gradient shows fi ve with scattered Pinus pumila “stlaniks” in the Anadyr-Penzhina sub- < 5.5) or in soils associated ranges, primarily in Asia. These grasses, it is similar in composition to cryptogam, cushion-forb barrens microsites commonly found in arctic landscapes. Information regarding the plant communities typically found in these province, but excludes areas of continuous stlaniks. (Unit B1). microsites was summarized in tables for each combination of bioclimate subzone and fl oristic region. This information with calcareous bedrock infl uences have restricted the Dominant plants: Upland areas have mainly oligotrophic hypoarctic Dominant plants: Grasses (e.g., Alopecurus alpinus, Dupontia then formed the underlying database for the map (Walker et al. 2002). shrubs (e.g., Betula nana/exilis, B. middendorfi i/glandulosa, Spiraea < 100 m (pH > 7.2). The latter often exchange of species between parts fi sheri, Deschampsia borealis/brevifolia, Poa abbreviata, P. arctica) stevenii, Vaccinium uliginosum, V. vitis-idaea, Ledum palustre ssp. have unique assemblages of and rushes (Luzula nivalisa, L. confusaa) are usually the dominant vas- 100-333 m of the Arctic. Russian geobotanists decumbens, Empetrum nigrum ssp. hermaphroditum). Thick moss car- cular plants. Forbs (Cardamine bellidifoliaa, Cerastium regeliin, Minu- endemic plant species. There pets are common in most shrublands (Hylocomium splendens, 334-667 m have described subdivisions artia rossiin, Papaver dahlianum ssp. polare, Potentilla hyparcticaa, Sphagnum, Aulacomnium turgidum, Sanionia uncinata). Along drain- are no common base maps that Saxifraga oppositifolian, Ranunculus hyperboreus, Draban, Stellarian, 668-1000 m based primarily on these fl oristic ages and near treeline, low and tall and alders are abundant Landscape Oxyria digyna) are abundant. Mosses are common (Aulacomnium tur- show this essential difference differences. The map shown here (Salix pulchra, S. glauca, S. richardsonii, S. alaxensis, S. krylovii, S. 1001-1333 m gidum, Tomentypnum nitensn, Ditrichumn, Oncophorus wahlenber- burjatica, S. boganidensis, S. arbusculoides, Alnus crispa, A. fruti- in substrate chemistry, so was adapted from the Panarctic gii, Polytrichum, Racomitriuma, Schistidium) and lichens (Lecanora, 1334-1667 m cosa). Salix glauca dominates this zonal tundra in Greenland. Some Biatora, Pertusaria, Ochrolechia, Thamnolia, Cetrariella, Flavoce- the map shown here was Flora Initiative (Elvebakk et al. trees reach into this subzone along the southern river valleys (e.g., 1668-2000 m traria, Stereocaulonn), and liverworts. Cryptogamic crusts composed of derived from a wide variety of Betula tortuosa, B. cajanderi, Populus balsamifera, P. suaveolens, 1999), based largely on Yurtsev cyanobacteria and black crustose lichens are common. In Subzone B, > 2000 m Chosenia arbutifolia, Larix laricina, L. cajanderi, Picea obovata, P. Acidic available sources including soil, prostrate dwarf shrubs (Dryasn, Salix polaris, S. arctican) and sedges (1994). glauca, P. mariana). Ice pH <5.5 (e.g., Carex aquatilis, Eriophorum) are present but not dominant. surfi cial geology, and bedrock Representative syntaxa: Communities of the classes Loiseleurio- Representative syntaxa: Communities of the class Thlaspietea Vaccinietea, e.g., Betulo-Salicetum glaucae Dan. 2002 prov. (Green- Circumneutral geology maps, and from rotundifolii Br.-Bl. et al. 1947 (Saxifrago stellaris-Oxyrion digynae land), Betulo-Adenostyletea Br.-Bl. et Tx 1943 and Salicetea pur- Topography strongly infl uences soil moisture and patterns of tundra plant pH 5.5-7.2 Gjaerev. 1950, e.g., Luzuletum arcuatae Nordh. 1928), and Salicetea spectral patterns that could be European Russia Beringia Canada pureae Moor 1958. communities. The topography map was divided into 333-m elevation intervals to herbaceae (Luzulion nivalis (Nordh. 1936) Gjaerev. 1956, e.g., Carbonate recognized on the AVHRR base -West Siberia Central Canada Alopecuro alpini-Tomenthypnetum (Hadac 1946) Dierss. 1992 and show approximate 2˚C temperature shifts in the mountainous areas (see explanation pH>7.2 Kanin - Pechora Wrangel Island Wetlands image. West Hudsonian Cerastio regelii-Poetum alpinae Dierss. 1992). Polar Ural - N. of elevation zonation in Figure 2). Areas below 100 m are separated to show low Ellesmere - Zemlya West Chukotka G2 W1 elevation plains. Data are at approximately 1 km spacing, taken from the GTOPO30 N. Greenland global digital elevation model (DEM) (Gesch et al. 1999). The landscape map was Yamal - Gydan East Chukotka G2. Graminoid, prostrate dwarf-shrub, forb tundra W1. Sedge/grass, moss wetland North Atlantic Moist to dry tundra in Subzone C and warmer parts of Subzone B on Wetland complexes of Subzones B and C, including water, low wet based on topographic data and regional landscape maps. Baffi n - Labrador East Siberia South Chukotka fi ne-grained, often hummocky circumneutral soils with moderate snow. areas and moist elevated microsites. Plant Biomass Taimyr This is the zonal vegetation on nonacidic soils of Subzone C. Plant Dominant plants: Sedges (Carex aquatilis, Eriophorum triste, E. Western Greenland scheuchzeri), grasses (Arctophila fulva, Alopecurus alpinus, Pleuro- Beringian Alaska cover is moderate (40-80%) and 5-15 cm tall. The diversity of plant Anabar - Olenyek Eastern Greenland communities is much greater than in Unit G1 and includes Cassiope pogon sabinei, Dupontia fi sheri, Poa pratensis), mosses (e.g., Cal- liergon giganteum, Warnstorfi a sarmentosa, Cinclidium arcticum, North Beringian tetragona snowbeds, well-developed mires, and streamside plant Lake cover Kharaulakh Islands Iceland - Jan Mayen Hamatocaulis vernicosus, Campylium stellatum, Plagiomnium ellipti- NDVI Aboveground plant biomass communities. Fennoscandia Dominant plants: Sedges (Carex misandra, C. lugens/arctisibirica/ cum, Bryum pseudotriquetrum), and forbs (e.g., Cardamine pratensis, Yana - Kolyma Northern Alaska bigelowii, C. rupestris, Eriophorum triste, myosuroides, C. Cerastium regelii, Caltha arctica, Bistorta vivipara, Saxifraga cernua, Svalbard - Franz-Josef aquatilis ssp. stans (moister sites)), rushes (Luzula nivalisa, L. con- S. foliolosa, Pedicularis sudetica). Grasses (Pleuropogon, Dupontia, fusaa), and prostrate dwarf-shrubs (Salix polaris, S. rotundifolia, S. Alopecurus) are more important in Subzone B wetlands than in Sub- arctica, S. reticulata, Dryas). Other common plants include grasses zone C. Elevated microsites have moist graminoid, prostrate dwarf- shrub, forb, moss tundra species such as Eriophorum triste, Carex (Alopecurus alpinus, Puccinellia vahliana, P. wrightii, Poa arctica), forbs (Potentilla hyparcticaa, Cardamine bellidifoliaa, Draba nivalis, misandra, C. membranacea, C. atrofusca, Kobresia simpliciuscula, Saxifraga cernua, S. hirculus, Stellaria, Pedicularis capitata, Papaver), Salix arctica, S. reticulata, and Tomentypnum nitens (see also Unit G2). References mosses (Racomitrium lanuginosuma, Oncophorus wahlenbergii, Representative syntaxa: Communities of the class Scheuchzerio- Campylium stellatum, Aulacomnium turgidum, Warnstorfi a sarmentosa, Caricetea; e.g., Poo arcticae-Dupontiae fi sheri Matv. 1994 (Taimyr Hylocomium splendens, Polytrichum), liverworts (Tetralophozia Peninsula), Meesio triquetrae-Caricetum stantis Matv. 1994 (Taimyr Alexandrova, V. D. 1980. The Arctic and Antarctic: Their Division into Geobotanical Areas. Cambridge Univ. Press, setiformisa, Anastrophyllum minutuma), and lichens (Sphaerophorus Peninsula), Eriophoretum scheuchzeri Fries 1913, Caricetum rari- Cambridge. globosusa, Cladina rangiferinaa, Cladonia pyxidata, Thamnolia, fl orae Fries 1913, Arctophiletum fulvae Thannh. 1976 (Svalbard), Plain Caricetum stantis Barrett & Krajina 1972. Bazilevich, N. I., A. A. Tishkov and G. E. Vilchek. 1997. Live and dead reserves and primary production in polar desert, Dactylina arctica, Flavocetraria, Masonhalea richardsonii). Hill tundra and forest tundra of the former Soviet Union. Pages 509-539 in F. E. Wielgolaski. (ed.). Polar and Alpine Representative syntaxa: Communities of the class Carici-Kobresietea, Tundra. Elsevier, Amsterdam. W2 Mountain e.g., Carici-Dryadetum integrifoliae Dan. 1982 (Greenland). Bliss, L. C. 1997. Arctic ecosystems of . Pages 551-683 in F. E. Wielgolaski (ed.). Polar and Alpine Tundra Glacier Vol. 3. Elsevier, Amsterdam. G3 W2. Sedge, moss, dwarf-shrub wetland Wetland complexes of Subzone D, primarily fens with slightly acidic Lake Chernov, Y. I. and N. V. Matveyeva. 1997. Arctic ecosystems in Russia. Pages 361-507 in F. E. Wielgolaski (ed.). Polar G3. Nontussock sedge, dwarf-shrub, moss tundra to circumneutral soil pH. Large components of moist nontussock and Alpine Tundra. Vol. 3. Elsevier, Amsterdam. Moist tundra mainly in Subzone D on peaty nonacidic soils; also found sedge, dwarf-shrub, moss tundra (see Unit G3) are usually present in Daniëls, F. J., H. Bültmann, C. Lünterbusch and M. Wilhelm. 2000. Vegetation zones and biodiversity of the North-Amer- slightly elevated microsites such as hummocks and rims of low- in Subzones C and E. Frost boils (barren patches of cryoturbated soil) <0.03 <50 g m-2 ican Arctic. Berichte der Reinhold-Tüxen-Gesellschaft 12:131-151. are common on silty soils (“spotted tundra” in the Russian literature). centered ice-wedge polygons. ESRI. 1993. Digital Chart of the World, Sept. 1993, Edition 1. Environmental Systems Research Institute Inc., Redlands, 50-100 g m-2 This is the zonal vegetation for much of Subzone D. Plant cover varies Dominant plants: Sedges (Carex aquatilis, C. chordorrhiza, C. 0.03-0.14 CA. rarifl ora, Eriophorum angustifolium, E. triste), grasses (Arctophila from 50 to100%. Plant heights are generally 10-20 cm. Hemiprostrate 0.15-0.26 101-250 g m-2 Edlund, S. 1990. Bioclimate zones in the Canadian Archipelago. Page 421-441 in C.R. Harrington (ed.). Canada’s Miss- and erect shrubs, such as Salix richardsonii, S. reptans, S. glauca, S. fulva, Dupontia psilosantha), and mosses (Pseudocalliergon ing Dimension: Science and History in the Canadian Arctic Islands. Canadian Museum of Nature, Ottawa. 251-500 g m-2 pulchra, S. krylovii and Rhododendron lapponicum, are common but brevifolius, Scorpidium scorpioides, Cinclidium latifolium, Meesia 0.27-0.38 triquetra, Catascopium nigritum, Distichium capillaceum). Prostrate Edlund, S. A. and B. T. Alt. 1989. Regional congruence of vegetation and summer climate patterns in the Queen Elizabeth generally do not form a closed canopy, and some may grow up to 40 0.39-0.50 501-1000 g m-2 Islands, Northwest Territories, Canada. Arctic 42:3-23. cm high at the southern Subzone D boundary. Low-shrub (40-200 cm dwarf-shrubs (e.g., Salix arctica, S. reptans, S. fuscescens) and forbs 1001-1500 g m-2 Elvebakk, A. 1999. Bioclimatic delimitation and subdivision of the Arctic. Pages 81-112 in I. Nordal and V. Y. Razzhivin tall) and some tall (>2 m) thickets occur along stream margins. (e.g., Pedicularis sudetica ssp albolabiata, P. penellii, Comarum 0.51-0.56 palustre) are often present. Acidic variants on raised microsites have (eds.). The Species Concept in the High North - A Panarctic Flora Initiative. The Norwegian Academy of Science and Well-developed moss layers (5-20 cm thick) are common. < 2% 0.57-0.62 1501-2000 g m-2 Letters, Oslo, Norway. Dominant plants: Mainly sedges (Carex arctisibirica/bigelowii/ hypoarctic, oligotrophic dwarf shrubs (e.g., Ledum, Salix pulchra, >2000 g m-2 Elvebakk, A., R. Elven and V. Y. Razzhivin. 1999. Delimitation, zonal and sectoral subdivision of the Arctic for the Pan- consimilis/lugens, C. misandra, C. scirpoidea, C. membranacea, Empetrum, Betula nana s.l., Vaccinium) (see also Units G4 and S1). 2-10% >0.62 Representative syntaxa: Communities of the class Scheuchzerio- arctic Flora Project. Pages 375-386 in I. Nordal and V. Y. Razzhivin (eds.). The Species Concept in the High North - A Eriophorum triste), prostrate and hemiprostrate dwarf shrubs (Dryas, Panarctic Flora Initiative. The Norwegian Academy of Science and Letters, Oslo, Norway. Salix arctica, S. reticulata, S. polaris, Arctous rubra, Cassiope Caricetea. 10-25% Gesch, D. B., Verdin, K. L. and Greenlee, S. K. 1999. New land surface digital elevation model covers the earth: EOS tetragona), and mosses and liverworts (Tomentypnum nitens, The normalized difference vegetation index (NDVI) shows relative 3000 W3 >25% ) Transactions, American Geophysical Union 80(6):69-70. Hylocomium splendens, Aulacomnium turgidum, Rhytidium rugosum, Figure 2. Elevation zonation maximum greenness. This image was created from the same data as the -2 Ditrichum fl exicaule, Distichium capillaceum, Ptilidium ciliare). Other Matveyeva, N. V. 1998. Zonation in Plant Cover of the Arctic. Russian Academy of Sciences, Proceedings of the Koma- W3. Sedge, moss, low-shrub wetland Vegetation in mountainous regions changes with elevation, forming distinctive elevational belts which correspond AVHRR base image. Vegetation greenness is calculated as: rov Botanical Institute, No. 21. (In Russian). 220pp. common plants include grasses (Arctagrostis latifolia, Deschamp- Wetlands in Subzone E, often bog/fen complexes with deep organic 2500 sia borealis, Poa arctica), basiphilous forbs (e.g., Bistorta vivipara, Lake cover strongly affects the albedo, or refl ectance, of the land surface over large approximately to the bioclimatic subzones. For every 333-m elevation gain, the mean July temperature decreases NDVI = (NIR – R)/(NIR + R), where NIR is the spectral refl ectance in Polunin, N. 1951. The real Arctic: suggestions for its delimitation, subdivision and characterization. Journal of Ecology soils. Large components of dwarf-shrub tundra (Unit S1) or tussock by about 2˚C, as predicted by the adiabatic lapse rate of 6˚C per 1000 m. Since only one elevational belt can be 39:308-315. Silene, Pyrola grandifl ora, Senecio frigidus, Pedicularis lanata, P. tundra (Unit G4) are usually present in slightly elevated microsites areas of the Arctic and is useful for delineating extensive wetlands. Lake cover was the AVHRR near-infrared channel (0.725-1.1 µm) where light-refl ectance represented on each polygon, the color of the lowest belt was used for the polygon, though higher elevational belts Tuhkanen, S. 1986. Delimitation of climatic-phytogeographical regions at the high-latitude area. Nordia 20:105-112. capitata, Chrysanthemum integrifolium, Tofi eldia coccinea, Lagotis, such as peat plateaus, and palsas. based on the number of AVHRR water pixels in each mapped polygon, divided by from the plant canopy is dominant, and R is the refl ectance in the red 2000 Eutrema edwardsii, Astragalus umbellatus, Sagina nivalis, Saxifraga may exist in that polygon. Mountain complexes were mapped by using a diagonal hatch pattern. The background Walker, M.D., F.J.A. Daniëls and E. Van der Maarel (eds.). 1995. Circumpolar Arctic Vegetation. Special Features in Dominant plants: Wet sites are dominated by sedges (Eriophorum the total number of pixels in the polygon. Since the imagery has a pixel size of 1 color and the orientation of the hatching represent the pH of the dominant bedrock (noncarbonate bedrock - mainly oppositifolia), and lichens (Thamnolia, Flavocetraria, Peltigera, Dac- vaginatum, Carex chordorrhiza, C. rotundata, C. rarifl ora) and mosses channel (0.5 to 0.68 µm), the portion of the spectrum where chlorophyll Vegetation Science, 7. IAVS and Opulus Press Uppsala, Sweden. 2 sandstone and granite vs. carbonate bedrock such as limestone and dolomite). The color of the hatching represents tylina arctica, Mycobilimbia lobulata, Cladonia pocillum, Psoroma (Sphagnum, Calliergon stramineum). The main plant communities km , lake cover is underestimated for areas with many small lakes. No pixels were absorbs maximally. The NDVI values were grouped into eight classes 1500 Walker, D. A., W. A. Gould, H. A. Maier, M. K. Raynolds. 2002. The Circumpolar Arctic Vegetation Map: AVHRR- hypnorum). the bioclimate subzone. As shown in Figure 2, a mountain in Subzone E could have six elevation belts (if the mountain on elevated microsites are shrublands with prostrate and erect dwarf- sampled within two pixels (2 km) of the coastline to avoid including ocean pixels. that meaningfully separate the vegetation according to biomass. Red and derived base map, environmental controls and integrated mapping procedures. International Journal of Remote Sensing Representative syntaxa: Dryado integrifoliae-Caricetum bigelowii shrubs (e.g., Ledum palustre ssp. decumbens, Vaccinium, Empetrum, is high enough). The lowest belt, Belt e is dominated by low-shrub tundra (S2); the next higher belt, Belt d has erect 23:2552-2570. Walk. et al. 1994 (Alaska, Subzone D, nonacidic tundra); Carici Rubus chamaemorus, Oxycoccus microphyllum, Salix richardsoniin, S. dwarf-shrub tundra (S1); Belt c has prostrate dwarf-shrub, herb tundra (P1); Belt b has rush/grass, forb, cryptogam orange areas in the NDVI map on the left are areas of shrubby vegetation 1000 Walker, D. A., H. E. Epstein, J. G. Jia, A. Balser, C. Copass, E. J. Edwards, W. A. Gould, J. Hollingsworth, J. Knudson, H. arctisibiricae-Hylocomietum alaskani Matv. 1994 (Taimyr Peninsula) fuscescens, S. myrtilloides, S. pulchra, Betula nana s.l.) and mosses. tundra (G1); Belt a has cryptogam, herb barrens (B1); and the nival belt is snow and ice covered (see Detailed with high biomass, and blue and purple areas are areas with low biomass. Maier, A. Moody and M. K. Raynolds. 2003. Phytomass, LAI, and NDVI in northern Alaska: relationships to summer (Scheuchzerio-Caricetea nigrae (Nordh. 1936) Tx 1937. Representative syntaxa: Plant communities of the classes Oxycocco- Vegetation Descriptions B3 and B4 at left for community descriptions). Vegetation is modifi ed by local topographic warmth, soil pH, plant functional types and extrapolation to the circumpolar Arctic. Journal of Geophysical Research 500 108(D2), 8169, doi:10.1029/2001JD00096. G4 Sphagnetea Br.-Bl. et Tx. 1943 and Scheuchzerio-Caricetea (Nordh. effects such as slope, aspect, and cold-air drainage. 1936) Tx. 1937 (cf. Ledo decumbentis-Betuletalia glandulosae Rivas- Acknowledgements The relationship between NDVI and aboveground plant biomass was Weber, H.E., J. Moravec, and J.-P. Theurillat. 2000. International Code of Phytosociological Nomenclature. 3rd edition. Martinez et al. 1999). Journal of Vegetation Science 11:739-768. G4. Tussock-sedge, dwarf-shrub, moss tundra calculated from clip harvest data (Figure 3). The aboveground plant Aboveground plant biomass (g m 0 Moist tussock tundra, mainly in Subzones D and E, on cold acidic 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 Westhoff, V., and E. Van der Maarel. 1973. The Braun-Blanquet approach. Pages 617-726 in R.H. Whittaker (ed.). Hand- a n This project was funded by the National Science Foundation (Grant OPP-9908829), with additional support from U.S. Fish and biomass map was created by applying this regression equation to the book of Vegetation Science. V. Ordination and Classifi cation of Communities. Junk, The Hague. soils. This is the zonal vegetation in Subzone E on unglaciated landscapes = acidic, = nonacidic Wildlife Service and the Bureau of Land Management. CAVM reviewers include: Susan Aiken, Hanne H. Christiansen, Bruce Forbes, Lynn Gillespie, Joyce Gould, Ole Humlum, Janet C. Jorgenson, M. Torre Jorgenson, Esther Lévesque, Nadezhda V. Mat- AVHRR data (Walker et al. 2003). Both the NDVI and the biomass maps NDVI Young, S. B. 1971. The vascular fl ora of St. Lawrence Island with special reference to fl oristic zonation in the arctic veyeva, Ingo Möller, Galina N. Ogureeva, Josef Svoboda, David K. Swanson, Charles Tarnocai, Dietbert Thannheiser, Tatyana aided in the delineation of the vegetation units on the front side. regions. Contributions from the Gray Herbarium 201:11-115. Yurkovskaya. Figure 3. Aboveground plant biomass vs. NDVI. Yurtsev, B. A. 1994. Floristic division of the Arctic. Journal of Vegetation Science 5:765-776.