The moss flora of Bering Island (Commander Islands, North Pacific)

Abstract

Moss flora of Bering Island, the westernmost in the Aleutian Archipelago, includes 312 species. This is the greatest number among islands of the North Pacific, including Kurils. Annotated list provides data on species frequency, habitat characteristics and associated species. Species composition in different types of habitats is overviewed. Ditrichum zonatum var. scabrifolium Dixon is new for Russia; five taxa, Bucklandiella macounii ssp. alpina, Didymodon vinealis, Lescuraea saviana, Philonotis capillaris, and Drepanocladus sordidus are new for Russian Far East, while five others, Didymodon insulanus, Claopodium bolanderi, Lescuraea baileyi, Rhytidiadelphus loreus, and Ulota phyllantha, have been known only from Medny Island, 70 km east of Bering Island. Comparison with a number of available regional moss floras on North Pacific indicates rather boreal than hypoarctic character of the moss flora of Bering Island, which in species composition is more similar to South Kamchatka, while by family composition exhibits sufficient similarity with Eastern and Middle Kamchatka. The sharpness of phytogeographic border between Commander Islands and Aleutians, the Tatewaki line, is confirmed.