Spatial structure and niche patterns of a rodent community in the south Bukhara desert (Middle Asia)

The distribution of niches in resource space and the niche patterns of a 13 species community of Middle Asian desert rodents were studied by use of discriminant function analysis Nineteen quantitative parameters of the environment (soil structure and vegetation), measured at 600 sample plots within twenty four one ha grids, were considered The first three canonical axes of resource space account for 83% of the variance, the first axis represents a general landscape gradient from sand to clay soils, the second axis reflects a gradient of increasing productivity, and the third axis reflects a gradient of increasing protectability of the environment The distribution of niches in resource space is not even, there are two distinct spatial guilds consisting of psammophilous and sclerophilous species There is a negative correlation between niche position (distance from species centroid to the center of the resource space) and maximal population biomass At the same time there are no correlations between the niche breadth and the niche position due to the absence of species with really broad niches Rodent biomass increases along the productivity axis and reaches a peak in the middle part of the substrate axis Rodent species diversity increases along the substrate axis from sand to clay soils Changes of species diversity along productivity axis have humpshaped patterns Maximum species diversity was recorded at low level of productivity on the sandy soils and shifted to intermediate levels of productivity on sandy-loam and clay soils