Myxomycetes of the winter-cold desert in western Kazakhstan

During a four-week expedition in April and May 1995, the winter-cold desert of the Mangyschlak Peninsula (52 degrees 13' E, 44 degrees 01' N) was surv eyed for myxomycetes. From about 1,000 substratum samples, 146 moist chambe r cultures were prepared. With the intention to check all suitable microhab itats, bark of all common desert shrubs, the rarely occurring accumulations of litter, and dung of various herbivorous animals were collected. For eac h culture, 5-10 individual samples of 2-3 pieces each were pooled from one microhabitat type. Although only two species with 10 collections were found in the field, the moist chamber cultures revealed a whole flora of desert myxomycetes. Twenty-seven species of myxomycetes, two members of the Protos teliales, and various Myxobacteria were recorded, often with exceedingly hi gh levels of abundance. Among these are numerous species previously conside red as rare, including Echinostelium arboreum, E. colliculosum, and Macbrid eola oblonga. For rare or taxonomically difficult species, brief taxonomic descriptions are given. Compared with surveys from other geographic regions , the desert flora encountered is rather poor but one of the most distincti ve among myxomycetes. In addition to obvious features such as absence of tr ees and succulent plants or the harsh, arid conditions, the high (7.5-8.0) pH of almost all of the substrata present seems to be a limiting factor.