Fauna of the Aleutian Islands and Alaska Peninsula
by Olaus J. Murie. Invertebrates and fishes collected in the Aleutians, 1936-38, by Victor B. Scheffer.
Published 1959 by Dept. of the Interior, U.S. Fish and Wildlife Service, Washington, D.C.
Some plant communities may be distinguished readily. Throughout all the coastal areas of southwestern Alaska the sandy beaches are bordered with a rank growth of wild rye. In the Aleutian district, other members of the Elymus arenarius, or wild rye, association are Senecio pseudoarnica, (a groundsel), Lathyrus maritimus (beach pea), Honckenya peploides, and Mertensia maritima (sea bluebell). Within this association we found the low-to-ground Honckenya peploides generally pushing out nearest the water. In many places the leafy, bulky Senecio pseudoarnica formed vigorous patches that virtually left no room for other plants. The Aleuts used the tall, coarse beach rye, Elymus arenarius, for weaving the exquisite "Attu" baskets.
Near the beach, but clinging to rocky sites, is Potentilla villosa, a herbaceous cinquefoil, which is associated with other plants. It is separate from the wild rye, or Elymus, association, though it is close to the tide, because its habitat is rock, not sand. Behind this beach-line association, on a somewhat drier area farther from the tide, was another zone of miscellaneous grasses, with some other plants. Here, we noted a dense stand of Poa, (blue grass), Calamagrostis (brown top), Bromus (brome), and other grasses that we did not observe closely ; however, we noted the demarcation between outer beach Elymus association and the adjacent inner zone of other grasses. The dividing line was not always located by a given distance from the beach. I recall a striking instance where a sloping bank arose from the beach to a height of about 30 feet. Elymus, exposed to the sands of the sea, clung to the open face of this slope to the crest. At the exact point where the ground levelled off toward the interior, the other, more inland, grass formation began with a dense growth. The plants of this inner group bordering the Elymus association are by no means confined to the vicinity of the beach ; instead, they become diffused among other plants farther inland.
Farther in the interior, and at higher elevations, we find what Hulten refers to as a "mosaic" of Alpine heath and meadow. Meadow formations have an abundance of Carex (sedge), together with many other species, though sedges occur elsewhere as well. In these meadows are found Artemisia unalaschensis (a herbaceous sage), Epilobium angustifoliuyn (fireweed), Calamagrostis landsdorffi (a brown top), Geranium erianthum (geranium), Anaphalis margaritacea (pearly everlasting), Aconitum kamtschaticum (aconite) , Polygonum viviparum (viviparous knotweed), Trientalis (star flower), Bromus aleuticus (brome), Castilleja unalaschensis (paint brush), Arnica chamissonis (arnica), and Aster peregrinus (aster). Such a meadow association, as defined by Hulten, is more characteristic of the eastern Aleutians. Prominent patches of the characteristic cotton grass, Eriophorum, and Ranunculus (bitterroot), were found in many wet areas. Here and there, were found Geum (avens), Caltha (marsh marigold), Habenaria (rein orchis), Lupinus (lupine), Geranium (geranium), and a botanical list too long to enumerate. In the more exposed situations above the meadows, scattered in accordance with the character of the terrain, are the heaths. Here, are lichens, mosses, crowberry (Empetrum, nigrum), and cranberry, (Vaccinium uliginosum) . Numerous other plants are distributed rather indiscriminately. The showy anemone (Anemone narcissiflora) , so prominent when in bloom, is very common.
Mention should be made of Heracleum lanatum (cow parsnip) and Coelopleurum gmelini (seacoast angelica). These robust plants grow throughout the Aleutian district, apparently where soil is rich. They are particularly conspicuous, together with other plants, on old Aleut village sites where the soil has been enriched by refuse from human habitation. Such village sites, seen at a distance, were recognizable by the deep-green, heavy vegetation.
On some occasions we would note a particularly green high mountain slope where we would find a colony of auklets nesting among rock crevices. We came to the tentative conclusion that vegetation grew more luxuriantly on the site of such bird colonies as a result of fertilization by bird guano and waste food. This vegetation was not necessarily of the same species as those growing on the Aleut village sites ; however, the reasons for its presence in the two instances may have been related.
Wind erosion is very severe on some exposures. In places, the wind had eroded the soil in troughs, undermining the vegetative turf to form a crude type of terracing. The woody roots of crowberry had been exposed and were already supporting a thin coating of lichens. With such constant wind action, one wonders how the vegetation became established in the first place. As shown in part c, wind erosion apparently had affected only the outer layer.
Marine vegetation is well represented by the kelp beds, which consist of a considerable variety of seaweeds that are prevalent throughout the Aleutian district. The kelp is, of course, the habitat of numerous marine organisms, and during the summer it furnishes a favorite habitat for the sea otter. These kelp beds disappear in the winter.
The oceanic climate of this region, the high humidity and precipitation, and the prevalence of strong winds have combined to shape the vegetative complex that we find in the Aleutian district. In turn, this complex, together with climatic conditions, topography, and the rich marine fauna, has influenced the composition of the indigenous fauna.