Vascular Vegetation of Buldir Island, .Aleutian Islaads; Alaska, Compared To

Ancm ' VOL. 37,NO. 1 (MARCH.1984) P. 37-48

Vascular Vegetation of Buldir Island, .Aleutian Islaads; Alaska, Compared to. Another Aleutian Island., G. VERNON.BY.RD'

ABSTRACT. The .vegetation of Blddir Island, Alaska, was studied from1974 to 1976. On this treeless volcanic island, two distinct vegetation complexes were conspicuous, one with relativelytall dominant plants .which generally occurredbelow 300 .m elevation (called the Lowland Tall-plant complex), and the other composed of muchshorterplants about 300 m elevationfcallekthe Upland.Short-plant complex), The lotvland complex con- tained eight plant communities, but over90% of the complex consisted of three; Elymus-umbet, Elymus-umbel-fein,and Cura-fescue meadow. The upland complex wasless diverse, containing only four communitiesof which the moss-willow tundra was the most widespread.At Buldir 119 species of vascular plants were identified, considerably fewer than at a nearby larger island, Amchitka. Key words: vascular plants, volcano, Aleutian Islands, plant ecology

RÉSUMI?. La v6g6tation de l'île Buldir, en Alaska, fut 6tudiC entre 1974 et 1976. Sur cette île volcanique d6pourvue d'arbres, deux complexes distincts de v6g6tation sonttvidents, l'un form6 de plantes dominantes relativement grandes, paraissant g6ntralementh une altitudede moins de 300 m (nomme le complexe des plantesde grande taille des ternwbasses), et I'autre.cornpo&.de plantes de .taille beaucoup plus petite trouvt?es B une altitude de plus de ,300 m (appel6 le complexe des plantes de petite taille des terres blev&s). Le complexe des terres basses comprenait huit com- munautCs de plantes, mais trois de celles-ci comptaient pour90% du complexe: Elyrmcs-ombellifbre, Elymus-ombelIiRre-fougbreet Cum-fbque- pr6. Le complexe des hautes terres ne @sentait pas une telle diversitt,.ne contenant quequatre communautts, dont la toundra de.mousseet desaule Ctait la plus dispers&. A Buldir, 119 espkxes de plantes vasculaires furent identifides,un nombre considirablement inf6rieur h celui du compte sur Amchitka, une île voisine-de taille supkrieure. Mots clts: plantes.vasculaires, volcan; îles Alhutiermes, kologie v6g6tale Traduit pour le journal par Maurice Guibord.

INTRODUCTION As part of an, ecologicalLevaluation of theendangered Aleutian Canada Goose; Brantacanadensis leucopareia, and,'other species of birds at :BuldirIsland, ,Alaska,this vegetation study was conducted during the summers,of 1974 through 1976;:The objectives. were to describe and delineate plant communities; to quantitatively assess community composition, and to iden- tify all vascular plant qecies on the island. The Aleutian Islands'.flora is relatively well known. Hultdn. (1960, 1968)made extensive collections and. summarized available information on plant distribution 'in..the Aleutians, I I but he wasnever ashore at Buldir. Only two small plant collec- lid tions have been made previously on the island (Coats, 1953); FIG. I. Map of the Ateutian Islands, Alah, with an enlargement of Buldir The only previous site-specific studies of plant communities in .Istand. the Aleutians were conducted OR Amchitka Island, 200 km east only permanent-wetlands are.Kittiwake Pond (1.2 ha), several of Buldir (Shacklette er, al., ,1969;Amundsen,. 1977): This small streams, and two small marshy areasless than .1 ha in ex- paper summarizes the study resultsat Buldir, and comparisons tent in the alluvial vaky.. are made between.the respective floras at Buldir and Am- U.S. Weather Service records, forShemya Island, 115 chitka. Nomenclature follows that of Huldn (1968). km west of Buldir, provide a useful indicator.of conditions at Buldir. Average monthly temperatures .range from O" C in STUDY AREA January and February to 9" C in August. At least partial over- Buldir is in the western Aleutian Islands (Fig. 1). It is the cast occurs on . more than 90% of the . days, and relative westernmost of the Aleutianvolcanoes that were still active in humidity near sea level averages over 90%. The region, is the Quaternary period (Coats, 1953). Buldir's surface area is famous for high wind velocity; the average at Shemya is over approximately 2000 ha and is composed of three volcanoes 30 bah", and velocities exceeding ,150 kmeh-l are recorded and an alluvial valley. The highest elevationis 655. m; A nari occasionally in winter. row, boulder-strewn beach is backed by nearly-vertical cliffs. Btrldir is.the. most isolated of the Aleutiawand has no pro- Steep (20" to Mo+)vegetated slopes, rising from cliff tops tected beaches for boat, landings. As a result, it is one of the toward the volcanicpeaks, arefrequently intersected by soil or few islandson which arctic foxes,Alopex lagopus, were never rock slides. Plateaus occur on the flanks of volcanoes..The introduced (Jones, 1963). Unlike most of theislands with

'Aladdin Route.Box 160 E, Colville, Washington 99114, .U.S.A. 38 G.V. BYRD

TABLE 1. Vascular plants found at Buldir Island 1974 to 1976

LYCOPODIACEAE PORTULACEAE CORNACEAE Lycopodium selago L. Claytonia sibirica L. Comus canadensis L. X suecica L. L. annotinum L. Montia fontana L. C. suecica L. clavatum L. L. CARYOPHYLLACEAE L. alpinum L. PYROLACEAE Stellaria calycantra (Ledeb.) Bong. L. sabinaefolium Willd. Pyrola minor L. crispa Cham. & Schlecht S. EMPETRACEAE SELAGINELLACEAE S. humifusa Rottb. Empetrum nignun L. Selaginella selaginoia'es (L.) Link Cerastium aleuticum Hult. EQUISETACEAE C. fischerianum Ser. ERICACEAE Equisetum arvense L. Sagina cmssicaulis S. Wats. Rhododendron camtschaticumPall. S. intermedin Fenzl. Loiseleuria procumbens (L.) Desv. ATHYRIACEAE Honckenya peploides (L.) Ehrh. *Phyllodoce aleutica (Spreng.) Heller) Athyrium felk-femina (L.) Roth Cassiope lycopodioia'es (Pall.) D. Don RANUNCULACEAE Vaccinium vitis-idaeaL. ASPIDIACEAE Anemone narcissiflora L. Dryopteris dilatata (Hoffm.) Gray Coptis trifolia (L.) Salisb. PRIMULACEAE *Polystichum braunii(Spenn.) Fee' *Ranunculus eschscheltzii2 Primula cuneifolia Ledeb. GRAMINAE *R. grandis Hod' Trientalis europaea L. Agrostis arata Trin. R. hyperboreus Rottb. GENTIANACEAE Bromus sitchensis Trin. R. occia'entalis Nutt. Gentiana aleutica Cham. & Schlecht. Calamagrostis nutkutensis (Presl.) Steud. CRUCIFERAE G. amarella L. Deschampsia beringensis Hult. Cochlearia oflcinalis L. SCROPHULARIACEAE Elymus arenarius L. Carahmine umbellataGreene Veronica americanaSchwein. Festuca rubra L. *Draba borealis D.C.3 V. grandiflora Gaertn. Phleum commutatum Gandoger D. hyperborea (L.) Desv. Pw arctica R. Br. V. serpyllifolia L. V. stelleri Pall. Puccinellia hgeana (Berl.) Sorens SAXIFRAGACEAE Mimulus guttatus D.C. *Arctophilafulva (Trin.) Anderss.2 *Saxrfaga aleutica Hult. I S. bracteata D. Don Rhinanthus minorLiive CYPERACEAE S. punctata L. LENTIBULARIACEAE Carex anthoxanthea&SI. *Chrysosplenium wrightiiFr. & Sav.3 Pinguicula vulgaris C. circinnata C. A. Mey. L. *C. enanden Hult.2 ROSACEAE PLANTAGINACEAE *C. glareosa Wahlenb.' Rubus arcticus L. Plantago macrocarpa Cham. & Schlecht. C. lyngbyaei Hornem. R. chamaemorus L. Potentilla egedii Wormsk. RUBIACEAE C. macrochaeta C. A. Mey. Galium trifidum L. C. pluriflora Hult. P. hyparctica Make. P. villosa Pall. CAPRIFOLIACEAE JUNCACEAE Sibbaldia procumbensL. Linnaea borealis L. Junncs arcticus Willd. Geum Menzies cathifolium CAMPANULACEAE Luucla multiflora (Rea.) Lej. macrophyllum Willd. G. Campanula himarpa Cham. L. parviflora (Ehrh.) Desv. *G.rossii (R. Br.) Ser' L. tundricola Gorodk. COMPOSITAE GERANIACEAE Erigeron peregrinus (Pursh) Greene LILIACEAE Geranium erianthurn D.C. Fritillaria catnschatcensis(L.) Ker-Gawl. Anaphalis margaritacea (L.) Benth. & Hook. f. Streptopus amplexifolius (L.) D.C. VIOLACEAE Achillea borealis Bong. Viola hgsdofi Fisch. *Artemisia unahkensis Rydb.1 ORCHIDACEAE ONAGRACEAE Arnica unalaskensis Less. Platanthem convallariaefolia (Fisch.) Lid. Chrysanthemum arcticumL. P. dikztata (Pursh) Limit. Epilobium behringianum Haussk E. glandulosum Lehm. *Cacalia auriculataD.C.' Listera cordata (L.) R. Br. Senecio pseudo-arnicaLess. SALICACEAE HALORAGACEAE Taraxucum trigonoloburn Dahlstedt. Salk arctka Pall, Hippuris monm Ledeb. Hieracium triste Willd. Salk sp. (either S. rotundifolia or S. ovalifoh) UMBELLIFEAE Petasites frigidus L. (Franch.) POLYGONACEAE Conioselinum chinense (L.) BSP Koenigia islandica L. Angelica lucida L. Rumex fenestratus Greene Heracleum htumMichx. Oxyria digyna (L.) Hill Ligusticum scoticum L. Polygonum viviparum (L.) S. F. Gray

*Does not occur at Amchitka. 'Nearest populations in western Aleutians or Asia. 'Range discontinuous, occurring in eastern and western, but not central, Aleutians. 'Occurs at elevations not found on Amchitka. VEGETATION OF BULDIR ISLAND 39

TABLE 2. Composition of Lowland Tall-plant communities at Buldir Island, Alaska

ElyM- Carex- Carex Artemisia- Elynuts- umbel- fescue lyngbyaei Umbel- Umbel- Species umbel fern meadow marshCalamagrostis Elymus fern OVERSTORY Elynucs arenarius 37.6' 16.6 4.0 8.0 1.7 (3.412 (3.6) (1.3) (2.3) ( 3) 90.23 71.6 35.0 53.3 20.6 Heracleum lonatum 20.9 20.6 29.3 29.5 (3.1) (4.0) (7.8) (12.7) 69.9 73.7 93.3 80.0 Angelica lucida 16.5 12.9 7.7 2.3 5 .o 27.0 (2.3) (2.3) (2.5) (2.4)(15.0) (2.1) 67.1 61.1 38.3 20.0 44.1 40.0 Athyrium felix-femina 18.1 23.5 (4.6) (16.1) 51.6 50.0 Fern spp.' 16.3 2.7 (4.9) (1.3) 31.6 15.0 Carex lyngbyaei 72.3 (7.3) 87.5 Arctophilo fulva 5.6 (4.8) 8.3 Artemisia unalaskensis 54.0 (9.5) 93.3 Calamagrosris nutkatensis 52.4 (3.7) 97. I Carex macmhaeta 9.1 (4.1) 47.1 Luucla parvifrora

Geum macrophyllum

Senecio pseudo-arnica

MIDDLE STORY Claytonia sibirica 22.3 40. I 73.7 31.0 (3.8) (4.8) (4.7) (7.4) 64.3 93.7 100.0 100.0 Festuca rubra 16.9 10.6 3.4 31.0 I .3 27.2 (3.3) (4.4)(1 3 (5.3) (1.0) (4.2) 53.8 23.2 95 .O 37.5 20.0 97.1 Cacalia auriculara 5.0 (1.3) 27.4 Achillea borealis 2.6 7.4 2.2 ( .6) (1.3) ( .6) 23. I 78.3 50.0 Angelica lucida 3.7 2.5 8.3 7.8 5.0 ( 3) ( 3) (1.5) (2.2) (4.2) 38.5 30.5 70.0 52.9 40.0 40 G.V. BYRD

TABLE 2. (Continued)

Elym- Carex- Carex Artemisia- Elym- umbel-.Umbel- , fescue lyngbyaei umbel- Species umbel fern meadow marsh Elymus Calamagrostis fern

Geranium erianthum 3.1 (1.1) 38.2 Carex macmhaeta 17.1 (4.1) 76.5 Epilobium behringianum2.3 3.8 (1.0) ( .8) 37.1 22.1 37.1 D@schampsiaberingensis

Ranunculus occidentalis1.6 2.4 1.2 2.1 5.0 ( 4 ( 5) ( .5) (1.4) (1.5) 25.2 25.3 25.2 26.7 40.0 80.0 Hemcleum~kanatum 3.7 9.0 (1.5) (8.5) 46.7 30.0 Geum macrophyllum1.2 1.7 2.7 3.5 ( 5) ( .5). ( .9) (2.8) 23.1 20.0 23.1 53.3 30.0 Epilobium spp.2.7 3.8 .4 .6 (1 .O) (1.0) ( .I) ( .7) 37.1 31.6 37.1 14.7 20.0 Athyrium felk-femina 2.8 3.2 1.5 ( 4 (1 3) (1.5) 28.4 50.0 20.0 Poa arctica 3.2 3.6 (4.9) (2.5) 33.0 52.9 Platanthera spp.

Ranunculus spp.

Fritillaria camschatcensis

Chrysanthemum arcticum 1.3 ( .7) 14.7 Luzuka pantiflora

Saxifmga punctata 2.1 ( 5) 14.7 Erigeron peregrinus 3.1 (2.5) 20.0 Anaphalis margaritacea 1.2 ( .7) 20.0 Trientalis europaea 41 VEGETATION OF BULDIR ISLAND

TABLE 2. (Continued)

Elymus- Carex- Carex Artemisia- Carex Carex- Elymus- Elymus- umbel- fescue lyngbyaei umbel- Umbel- um bel fern meadow Species fern umbel marsh Elymus Cahmagrostis fern

Galium trifidum , 1.7 (1 .O) 25.0 Conioselinum chinense .9 (1 .O) 20.8

Fern SQQ.

Veronica americana 2.5 (1.3) 33.3

GROUND STORY Cardamine umbellata 7.7 10.3 6.6 12.0 .7 (1.0) (2.0) (1.6) (2.0)( .I) 84.6 89.5 79.2 100.0 32.4 Moss 36. I 40.4 27.6 10.4 60.0 (3.6) (5.6) (7.8) (10.1) (2.1) 90.2 86.3 79.2 100.0 82.4 Coptis trifolia 3.3 3.6 1.7 6.0 2.0 (1.0) (1.1) ( .7) ( 3) (1.4) 76.2 71.6 58.3 90.0 19.4 Epilobium sp. .5 1.2 3.1 .6 ( ( .I) ( .4) (1.1) .7) 20.3 53.7 62.5 20.0 Ranunculus SQQ. .2 .3 .6 .9 ( .I) ( .I) ( .I) ( .7) 18.2 18.9 21.7 50.0 Stellaria spp. .9 1 .o .3 ( .I) ( .3) ( .I) 24.5 28.4 15.0 Liverwort I .9 1.6 3.7 ( .3) ( 3 (2.3) 19.6 22.1 26.7 Saxifraga bracteata 2.6 ( .6) 22.4 Achillea borealis .I ( 3 20.8 Galium trifidum 2.8 (1.1) 54.2 Ranunculus eschscheltzii 20 .o Sample Si = 95 I43 60 24 15 34 10 'Mean percent cover value. *Standard deviation in parentheses. 'Frequency of occurrence expressed in percent. 'Mostly Athyrium, but some Dryopteris and Polystrichum. 42 G.V.BYRD

TABLE 3. Composition of Upland Short-plant communities at Buldir Island, Alaska

Species Moss-willowFell-field Moss-willow Empetrum Talus MIDDLE STORY' Salk spp. 15.6* 6.2 (2.2)Z (1.7) 86.8. 76.5 Carex spp. 4.4 2.3 ( .7) ( 3) 72.4 64.7 Polygonum viviparum 3.4 .9 ( .4) ( .I) 68.4 64.7 Veronica spp. 3.3 ( 5) 61.8 Festuca rubra 5.0 .6 58.3 (1.0) ( .4) (9.1) 60.5 30.6 100.0 Geum spp. 5.0 2.1 (1.0) ( .9) 56.6 41.2 Arnica unakaskensis 4.1 .2 1.2 (1.0) ( .I) ( .6) 53.9 17.6 58.3 Sibbaldia procumbens 3.6 .8 1 .o ( 4 ( .5) ( .4) 50.0 35.3 58.3 Viola langsdo@ 2.4 .7 ( 5) ( .4) 46.1 33.3 Achillea borealis 3.8 2.5 (1.1) ( 1.4) 46.1 27.8 Primuh cuneifolia 3.0 .8 1.1 ( .9) ( .3) ( .4) 44.7 52.9 75.0 Chrysanthemum arcticum 1.7 ( .5) 32.9 Trientalis europaea 1.6 ( .4) 31.6 Comus suecica 1.6 ( 4 18.4 Epilobium spp. 1.3 ( 3) 18.4 Carex circinnata 1.2 5.3 ( .7) ( .7) 15.8 97.2 Deschampsia beringensis .6 ( .4) 22.2 kuhtundricola

Geum calthifolium 1.5 ( .7) 61.1 6.2 (3.5) 44.4 .3 ( .I) 27.8

42.4 7.9 20.8 29.2 (4.6) (2.0) (3.7) (7.0) 98.7 94.1 100.0 88.9 9.8 4.4 5.0 3.3 (1.3) (1.4) (1.3) (1.9) 80.3 100.0 80.6 27.8 5.2 2.8 11.2 (1.7) (1.0) (2.2) 55.3 64.7 77.9 4. I 28.3 (1.4) (4.0) 27.6 91.7 4.4 (1.5) 25.0 1.6 ( .9) 19.7 2.3 ( .9) 18.4 I .8 ( .5) 80.6 3.5 (1.3) 61.1 .5 ( .4) 19.4 I .4 (1.2) 16.7 6.6 (2.1) 88.9 9.7 (2.3) 83.3 6.7 (2.9) 55.6 44 G.V. BYRD

TABLE 3. (Continued)

Species Moss-willow Fell-field Moss-willow Fell-field Moss-willow Species Empetrum Talus

Saxifraga bracteata

Coptis trifolium

‘No overstory in the Upland Short-plant community. ’Mean percent cover value. ’Standard deviation in parentheses. 4Frequency of Occurrence expressed in percent. foxes, Buldirhas a diverse seabird populationof over one RESULTS million birds (G.V. Byrd, 1978, unpub. rep. in files of U.S. Of the 119 species of vascular plants in 36 families identified Fish and Wildlife Service, Adak, Alaska), which may have a at Buldir (Table l), only about 30 are common enough to ac- fertilizing effect on the vegetation. count for at least 5% of the cover in any of the plant com- Human occupation of Buldir has been relatively sparse: one munities (Tables 2 and 3). Approximately 55 taxa occur in at Aleut hunting camp (McCartney, 1977) and a small weather least 15 % of the plots. The Lowland Tall-plant complex oc- detachment of approximately 12men during WWII (U.S. curs generally below 300 m elevation and includes eight com- Department of Defense records, Washington, D.C.). As a munities, seven of which are quantitatively described (Table result, Buldir has escaped the major disturbance seen on Am- 2). The Upland Short-plant complex occurs generally above chitka and many other islands. 300 m elevation and includes four communities which are quantitatively described (Table 3). The distribution of com- METHODS munities is illustrated (Fig. 2). Dominant plants below 300 m elevation were generally tall, LOWLAND-TALL PLANT whereas upland plants were short; therefore, two vegetation complexes were defined: the Lowland Tall-plant and the POINTNORTHWEST COYPLEX Upland Short-plant. Each complex was subjectively sub- divided into communities recognizable by major differences in species composition. Community boundaries were located visually anddrawn on 1:25 000-scale maps. The percent cover CAPE of each species in various communities was estimated by a two-stage, systematic sampling technique with replications. A random number table was used to select 1-m-wide strips in each delimited plant community, and the relative coverage of each species was visually estimated in five randomly-selected 1-m2plots in each 50-m length of transect. The random num- bers selected were used for replication in every 50-m segment of a transect until a community boundary wasreached. Within each plot the percent cover values of each species were recorded for eachof three vertical height categories (i.e. Elvmur-umbl b-fescueOOther plont comrnunlhes stories): overstory, the tallest plant level; middle story, Q Uym-umbl-fern Moss-Willow Rock Slide generally 10-25 cm tall; and ground story, plants c 10 cm tall. FIG. 2. Map showing the distribution of plant communities atBuldir Island, Alaska. As indicated, thewhite areas represent all the minor communities Cover values were arrived at by estimating percentages of a (e.g. mostly Calamagrosris, but also the Carex lyngbyaei marshes and umbel- plot that were actually occupied by a plant species, and the fern community at the base of Northwest Point, Elymus-umbel-Artemisia near combined values of a story seldom totalled 100% (e.g. a mid- East Cape, Cochlearia-Achillea near base of north arrow, and moss-willow- Empetrum at northwestern edge of the moss-willow-tundra community). The dle story was frequently composed of up to 20% stems of primary fell-field areas are under the words, “Upland Tall-plant Complex”. overstory plants or, in other cases, open space). Plots were sampled from mid-July to early September, during or just after Lowland Tall-plant Complex the main flowering period. Every species of vascular plant found at Buldir was collected and determined, and voucher Elymus-umbel community specimens were deposited in the herbarium at the University This is the most extensive lowlandcommunity (Table 4, of Alaska (ALA). Fig. 3), occurring on all aspects and reaching from just above BULDIR ISLAND ,VEGETATION OF BULDIR 45

TABLE 4. Surface areasand average overstoryheightof plant communities .at Buldir. Island, Alaska

Areacovered Canopy Height(cm) Sample Community Ha (X) Mean S.D. size Lowland Tall-plat Elymus-umbel 287.9 (14.3) 58.9 3.8 Elymus-umbel-fern 203.3 (10.1) 72.1 2.8 Carex-fescuemeadow 175.3 (8.7) 37.6 4.1 Cochlearia-Achillea (0.7) 14.6 - - Carex lyngbyaei marsh 14.1 (0.7) 52.6 3.9 Arremesia-umbel- Elymus 11.2 (0.6) 41.5 1.8 Calamagrostis (0.4) 7.4 52.2 2.0 Umbel-fern (0.4) 7.3 79.4 4.9 Upland Short-plant Moss-willow tundra 869.9(43.4) 22.4' - - E[ymus-umbel plant community at Buldir Island. Fell-fieldFIG.Island. Buldir 3. E[ymus-umbel community atplant 130.7 (6.5) 5.02 Moss-willow- Empetrum (2.5) 49.2 - - sea. levelto the. upper reaches.of thelowland complex. The Talus 8.5 (0.4) 16.7' 2.2 overstory averages nearly60 cm tall, but it frequently exceeds 1 m. Elymus arenarius, Heracleum lunatum, and Angelica Other Recent slidesRecent (10.5)212.6 - - 'lucida are the most-important overstory species. In the middle Lakes ponds and 13.2 (0.7) - - story Claytonia sibirica .and Festuca mbra are dominant. No - "" ___ zw3.z- other species has high cover values., but thisdiverse storycon- .IUIAL tains 45 species; Unidentified mosses cover over 35% of the .'Maximum height of scattered tall plants; usually no overstory. ground story (Table 2) where Cardamine umbellata and Coptis 'Tallest plant recorded; most were shorter. 'Refers to middle. story; no overstory. trifolia are ubiquitous.but have low cover values. Seventeen other species.occur in the ground story.

Elymus-umbel-fern community This community is situated mostly on southern, southeast- ern, and eastern sea-facing slopes (Fig. 4). It has one of the tallest overstories (Table 4), and it was subjectively determined to have a relatively high stemdensity. The overstoryin- cludes the three dominant species in the Elymus-umbel community. Nevertheless, Elymus arenarius is less important, although it is found in over 70% of the plots. Instead, Athyrium felix-femina is much more important. Heracleum lunatum and Angelica lucida have similar cover values and frequencies of occurrence in the two communities. The cover value estimated for Athyrium (Table 2) is probably too low since a significant portion of the value. for unidentified fern could probably be .referred to Athyrium felix-femina. The Elymus-umbel-fern community has an overstory diver- sity similar to the Elymus-umbel community, approximately 2 1 species. Claytonia sibirica is the most common plant in the middle story, but 34 other species are found. Mosses cover about 40% of the ground, and 17 other species occur.

Carex-fescue meadow community This community is most frequently found at the upper edge of the lowland complex. The key overstory species are Carex macrochaeta and Angelica lucida. The middle story is one of

thdmost diverse, containing 51 species. Festuca rubra is the - .- - . " FIG. 4 Elymus-umbel-fern community at Buldir Island. Note height of over- primary species; but Angelica lucida, Achillu borealis, Carex story. 46 G.V.BYRD macrochueta, and Geranium erianthum are also common. The Upland Short-plant Complex ground story is diverse, containing 19 species. Mosses are Moss-willow tundra community most common, and Coptis trifolia and Cardamine umbellata This community is the most extensive on Buldir (Table 4, are frequently found. Fig. 5) covering over 80% of the upland complex. The community has scattered tall plants, butonly the middleand Carex lyngbyaei marsh community ground stories are well developed. Areas of solifluction give The only two Carex marshes at Buldir occur along the west- parts of this community a stair-step appearance, caused by ernmost stream in the alluvial valley. Carex lyngbyaei forms alternating strips of vegetation and bare soil, .3 to 1 m wide. dense stands averaging over 50 cm tall in standing or slowly Several species of willow (including S. arctica) are dominant. moving water. Luzula parvijlora and Arctophila fulva are the Carex spp., Polygonumviviparum, Veronica spp., and only other common overstory plants, although 15 other species are recorded. Common middle story plants are Festuca rubra Festuca rubra are also found frequently, but all have cover values of less than 5 % . The middle story has at least 38 dif- and Epilobium behringianum, and 28 other species occur in ferent species. this layer. Mosses are the most common ground story plants.

Artemisia-umbel-Elymus community This restricted community occurs in isolated patches on northeast and southeast slopes in draws or creek drainages. Artemisia unalaskensis and Heracleum lunatum are the major overstory species. Elymus arenarius occurs in over 50% of the plots, but it has a low cover value. Only four other overstory species are found. Claytonia sibirica is even more common in this community than in the Elymus-umbel and Elymus-umbel- fern communities. It nearly excludes other plants, covering nearly 75% of the story. Mosses dominate the understory. Cardamine umbellata and Coptis trifolia are frequently recorded, but they have low cover values.

Calamagrostis community Most of the relatively flat alluvial valley is covered by this community, and patches are also found on the lower adjacent slopes. This community has verya high stem density. FiCi 5 The moss-willow tundra community at Buldir Island. Calamagrostis nutkatensis dominates the overstory, but Carex macrochaeta and Angelica lucida are also important. The middle story has Festuca rubra, Carex macrochaeta, and 18 other Mosses cover over 40% of the ground in this community. species. Dead plants, representing undecayed production from Various unidentified lichens, Cassiope lycopodioides, and previous years, cover over 80% of the ground story. Empetrum nigrum are also frequently found. The moss-willow tundra has one of the most diverse ground stories, 30 species.

Umbel-fern community Fell-field community This tall community is found primarily near the base of This community occurs on windswept ridges and plateaus at Northwest Point in relatively deep soil, riddled with nesting high elevations (Fig. 6). To be classified as fell-field an area burrows of Storm Petrels, Oceanodroma spp. Elymus must have less than 20%plant cover. The tallest plant found in arenarius is practically absent whereas Heracleum lunatum, this community is 5 cm tall, so no overstory is identified. Salk Athyrium felix-femina, andAngelica lucida dominate the over- spp. is the only taxon in the middle story with a cover value story. Claytonia sibirica is the most common species in the greater than 5%, though 14 other species are recorded. Like middle story. Ranunculus occidentalis is also frequently the middle story, the ground story is mostly bare or covered by found, and eight other species are present. Mosses blanket ap- gravel. Mosses are the dominant species, and lichens occur in proximately 60% of the ground story, where Cardamine every plot. umbellata and Coptis trifolia are also important. Moss-willow-Empetrum community Cochlearia-Achillea community Scattered patches occur at lower edges of the upland over- No quantitative description was made for this community looking the alluvial valley. There is no overstory. A thinly which occurs in scattered locations along the few sandy shore- vegetated middle story contains Salk spp., Geum calthifolium, lines just above high-tide line. The most common species are and Carex circinnata. A thickmat of Empetrum nigrum, Cochlearia oficinalis, Achillea borealis, Draba hyperborea, mosses, Cassiope lycopodioides, and 10 other species of dwarf Senecio pseudo-arnica, and Honckenya peploides. plants, interspersed with bare areas, form the ground story. VEGETATION OF BUILDIR ISLAND 41

introductions. In contrast, Buldir has hadvery little human activity. Two families found on Amchitka but not on Buldir include species that grow on sandy beaches, which are fairly widespread at Amchitka butvery restricted at Buldir. The other two families found on Amchitka but not on Buldir, Iridaceae and Papaveraceae, include a single species each. The most striking difference between the floras of Amchitka and Buldir is the relative extent of Empetrum-dominated communities on Amchitka and Elymus-dominatedcommunities on Buldir. Empetrum nigrum is the most important plant in two communities that together cover approximately 55% of Am- chitka (Amundsen, 1977). Mixedwith Empetrum in these communities are numerous species of the grass, sedge, and rush families. These families include 55 species at Amchitka but only 2 1 at Buldir, where the only communitydominated by Empetrum covers less than 3% of the island. The genera Pou and Carex and the species Calamagrostis nutkatensis are better FI(;. 6 The fell-field community at Buldir Island. Note the lush lowland asso- ciation far below. represented and more widespread at Amchitka. The Empe- trum-grass-sedge communities occur at Amchitka from a few feet above sea level to above 250 m elevation, on nearly flat to Talus community moderate slopes (Amundsen, 1977). These rolling plateaus at Vegetated boulder slides occur locally from sea level to over low elevations are widespread on Amchitka but nearly absent 500 m elevation. Although the community spans both the low- on Buldir, where steep slopes rise quickly to high windswept land and upland complexes, it is placed in the upland because plateaus and peaks. The steep slopes below approximately 300 it most resembles communities in that complex. As in other m on Buldir are primarily covered by two communities upland communities, no overstory occurs. Festuca rubra dominated by Elymus arenarius. The community dominated covers over 50% ofthe middle story. Dryopteris dilitata, by this species on Amchitka, andon many other Aleutian Angelica lucida, Achillea borealis, andEpilobium behring- Islands (V. Byrd, pers. obs.), is restricted to a narrow fringe ianum are found frequently, but onlyAngelica has a cover along the coastline and covers only 2% of Amchitka. value of over 5%. The ground story includes 14 taxa. Mosses, Amundsen (1977) is one of several authors who have no- Stellaria spp., Cardamine umbellata, liverworts, andSaxi- ticed the particularly lush vegetation, frequently Elymus, and fraga bracteata are all important. several umbellifers, associated with remains ofold native villages. The lushness is attributed to fertilization from DISCUSSION decayed faunal remains. The feces from over one million sea- Buldir’s vascular flora is less diverse than that ofAmchitka: birds on Buldir must provide fertilization and may at least par- 1 19 species in 36 families compared to 206 species in 46 tially account for the extent of this normally restricted com- families (Amchitka totals from Amundsen, 1977). A community. Another factor probably involved is drainage. Elymus parison of the vegetation on the two islands is interesting be- communities elsewhere are normally found on fairly sandy, cause they approximate the extremes of the range of habitat well-drained sites. The steep hillsides on Buldir have loamy diversities found in the Aleutians. Many of the larger islands soils, and drainage is good. (e.g. Amlia, Atka, Adak, Kanaga, Tanaga) are similar floristi- Buldir has 13 species of plants not found at Amchitka: Six of cally to Amchitka, whereas some of the smaller volcanic these are primarily Asiatic or western Aleutican in origin, and islands (e.g. Chagulak, Kasatochi, Gareloi, Segula) may be apparently Buldir is at,or near, the eastern edge of their similar to Buldir. ranges. Four of the remaining species are found at elevations It is not surprising that four of the eleven plant families and on Buldir which exceed the highest occurring at Amchikta. numerous species found on Amchitka but not on Buldir were Coats (1953) pointed out that the relatively restricted flora associatedwith freshwater ponds. Amchitkahas over 2000 of Buldir might be attributed to its isolation and small land ponds (J.A. McCann, 1963, unpub. rep. in files of U.S. Fish area, which reduce the chances of dispersing seeds landing on and Wildlife Service, Anchorage, Alaska) compared to only suitable sites for establishment. He also suggested that two small potholes andKittiwake Pond on Buldir. Three addi- restricted flora might indicate that Buldir is geologically tional families and several species unique to Amchitka have younger than islands to the east and west. disjunct distributions and probably were introduced by humans. These introductions are understandable since ACKNOWLEDGEMENTS thousands of military personnel and tons of equipment were This study was funded by the U.S. Fish and Wildlife Service, and moved to theisland during WWII. More recent activities the following Service employees (at the time of the study) are grateful- associated with nuclear testing also provided opportunities for ly acknowledgedfor their assistance: field work, Matthew Dick, G.V. BYRD

W,illiamRodstrom, and John Trapp; data analysis,Radstrom, .' MichaelSpindler, and James Swartwood (U.S.Naval Torpedo Laboratory);.logistics, Christian ..Anderson, Dave Clemens, and GeorgePutney.. Particularly useful suggestions were .made during ' manuscript preparation by Robert:Day, L.V. Hills, Claudette Reed Upton, Fred Zeillemaker; .and two anonymous referees.

REFERENCES

.' AMUNDSEN, C.C. 1977. Terrestrial plant ecology. In: Merritt, M.L. and Fuller, R.G. (eds.).The Environment of Amchitka Island, Alaska.Tech- nical Information Center, .Energy Research and Development Administra- tion, Springfield, VA. COATS, R.R. 1953. Geology ofBuldir Island, Aleutian Islands, Alaska. U.S. Geological Survey Bulletin 989A. 26 p. HULTfiN, E. 1W. Flora of the Aleutian Islands. 2nd edition. Weinheim: J. Cramer; Hertfordshire, England: Wheldon and Wesley Ltd. 376 p. -. ,1968. Flora of. Alaska and Neighboring Territories. Stanford: Stan- . ford-University Press. lo08 p. JON=, R.D. 1%3. Buldir Island, site of a.remnant breeding population of Aleutian Canada Geese. Annual Report of the. WildfowlTrust 14:80-84. McCARTNEY, A.P. 1977. Prehistoric,human occupation of the Rat Islands. In: .Memitt,M.L. and Fuller, R.G. (eds.).The Environment of Amchitka Island, Alaska. Technical Information Center, Energy Research and De- vetopment Administration, Springfield, VA. 59-1 13. SHACKLETTE, H.T. et al. [8additional authors]. 1969. Vegetation of Am- chitka Island, Alaska. U.S. Geological Survey Professional Paper 648. 66 P.