VEGETATION AS A FACTOR OF SPECIES-DIVERSI TY IN DESERT RODENT COMMUNITIES

Diversity of rodent species was studied in relation to the abundance o f grass vegetation, projection cover of arboreal and semi-arboreal veg etation, and mechanical soil composition in the Kyzyl Kum desert (Bukh ara district, Uzbekistan) and in the Chihuahua desert (Bolson de Mapim i, Durango, Mexico), Species diversity indices for rodent communities in l-hectare plots significantly varied in both deserts in similar env ironmental conditions. Nevertheless, the obtained data agree with the data on the hill-shaped relationship between species diversity and pro ductivity of the environment. Stepwise regression analysis of the line ar component links suggests that the abundance of grass and the projec tion cover of arboreal and semi-arboreal perennials, rather than the t ype of soil surface, exert a significant influence on the diversity of rodent species. At a given projection cover of arboreal and semi-arbo real plants (or an abundance of grass), the diversity of rodent specie s in Bukhara decreases with an increase in grass abundance (or project ion cover of arboreal and semi-arboreal plants). By contrast, in Mapim i the diversity increases. The difference is probably due to both spec ific environmental conditions and particular fauna genesis.