The moss flora of Olskoye Plateau (Magadan region)

1 Botanical Garden-Institute FEB RAS, Vladivostok, Russia
2 Institute of Biology and Soil Science FEB RAS, Vladivostok, Russia

Olskoye Plateau is located in the southern part of the Kolyma Upland. It covers a range of elevations from 1100 to 600 m. a.s.l., and is composed by tabular Tertiary basalts. The climate is moderate continental, the mean of January (coldest month) temperature is -32C, the mean of August (warmest month) temperature is the +11 - +12C, the mean annual temperature is -1.5C. The plateau is located in the permafrost zone and, due to poor drainage of basalt rocks, is characterized by extreme ground moisture in comparision with the adjacent landscapes. The plateau is covered by subalpine vegetation with Larix forests rising up to 1000-1100 m a.s.l. usually with an undergrowth of Pinus pumila. The alpine belt is occupied by different types of tundra: herb-moss, moss-dwarf-shrub, moss-lichen. The very diverse vascular plant flora of Olskoye Plateau is well studied compared with only a limited study of the mosses. During the present work, we have identified 135 species and 2 variations of mosses, belonging 30 families and 66 genera. The distribution of many taxa was very clear. Five species and one variety (Brachythecium jacuticum, Bryum longisetum, Dicranum bardunovii, Orthothecium rufescens, Sphagnum rubiginosum, Hylocomium splendens var. alaskanum) were firstly recoded for the North-East Asia. Hygrohypnum cochlearifolium and Pohlia berengensis were previously found in Chukotka and Schistidium obscurum only in Kamchatka Territory. Fifty-seven taxa (Bryum creberrimum, Bryum pseudotriquetrum, Fissidens bryoides, Polytrichum strictum, Warnstorfia fluitans, etc.) were recorded for the first time for the Magadan Province. The leading familes of floristic composition are Bryaceae (14 species), Sphagnaceae (12 species), Mniaceae (10 species). Geographically bryoflora of Olskoye Plateau is arctic, with a large number of hypo-artic (Tomentypnum nitens, Meesia triquetra, Paludella squarrosa, Bartramia ithyphylla, etc.), arctic (Brachythecium udum, Cinclidium subrotundum, etc.) and arctic-alpine species (Philonotis tomentella, Aulacomnium turgidum, Racomitrium lanuginosum, etc.).

2012 Organizing Committee