TEMPORAL AND SPATIAL VARIATION IN STRUCTURE OF SMALL MAMMAL COMMUNITIES - RODENTS OF TRANS-ALTTAI GOBI OF MONGOLIA

Between year variation of rodent population densities was studied in t he central part of Trans-Altai Gobi, Mongolia, in summers of a nine ye ar period. Variation in spatial structure of the desert rodent communi ty in 1982-84 and in 1992 was examined by the use of discriminant func tion analysis. Although population densities, breadth and positions of niches of many species tended to vary independently, the positive con junct variation was found for the most ecologically distinctive specie s. This can be explained by limitations of the climate. Although a gui ld structure of the community was pronounced each year, there were sig nificant between year shifts in niche breadth and niche centres along certain axes of ecological space. Within year nearest neighbours in ni che overlap (high seasonal overlap) differed in between year variation in abundance. It is supposed that interspecific competition could con tribute to development of community structure.