Ferns in the present-day periglacial zone of the Central Altai

Abstract

This article presents data on the species composition and distribution of ferns in the present-day periglacial zone of the Aktru, Karagemskiy, Akkem, Sofiiskiy, Gebler, and Taldurinskiy glaciers in the Central Altai. Sixteen fern species have been found and confirmed by herbarium specimens. Botrychium lunaria (L.) Sw., Cystopteris dickieana R. Sim, C. fragilis (L.) Bernh., and Polystichum lonchitis (L.) Roth were the most tolerant to the severe conditions of high mountains. The distribution of ferns in the centers of the present-day glaciation was related mostly to the occurrence of rocks. Colonization of the periglacial zone by ferns occurred only by means of spores, initially by their introduction from habitats located far from the periglacial zone. The further colonization and migration of species, following the retreating glaciers, was possible by means of spores produced by sporophytes growing in the periglacial zone. Germination of spores and development of gametophytes and sporophytes under severe conditions of the periglacial zone generally occurred in local microlandscapes providing protection in the cold season and a sufficient amount of moisture in the warm season.