干旱区生态环境知识资源中心

A rapid biodiversity assessment for myxomycetes (plasmodial slime moulds or myxogastrids) was carried Out during the 1995 to 2005 field seasons in the desert and steppe regions of the Lower Volga River Basin. The general area investigated represents the northwestern portion of the Caspian Lowland Of Russia and adjacent areas of Kazakhstan. Because of the very arid climate of this region of the world, specimens obtained with the use of the moist chamber culture technique formed a major part of the survey. At least 158 species of myxomycetes representing 35 genera were identified from 3227 records that originated from 852 field collections arid 2379 collections obtained from 1470 moist chamber cultures prepared with samples of bark from living plants, litter and the dung of herbivorous animals. Both species richness and diversity increased along the gradient of vegetation from sagebrush desert to woodland. The myxomycete biota of this region displays a high level of similarity to those of other arid regions of the world for which data exist but differs considerably from the biotas of temperate, boreal arid tropical regions. Seventeen species were recorded for the first time from Russia. Small corticolous (bark-inhabiting) species were found to be characterized by smaller niche breadths than litter-inhabiting species arid seem to be more specialized than other ecological groups of myxomycetes. Maximum diversity for corticolous myxomycetes was recorded for plants (e.g., Calligonum aphyllum arid Omits pumila) that have deeply furrowed bark. The most specific arid poorest corticolous myxomycete biota was recorded for the bark of Tamarix.