GEOGRAPHY OF MAMMAL DIVERSITY AND SEARCHING FOR WAYS TO PREDICT GLOBAL CHANGES IN BIODIVERSITY

Geographic ranges of mammals from territory of the former USSR were ma tched by use of IDRISI 4.1 software for mapping mammal species richnes s (all mammals and, separately, quadrupeds and bats). Plains landscape s are characterized by a regular increase of mammal species richness f rom tundra to forest-steppe zone, where the Budyko-ratio index of arid ity equals 1, then a decrease. Continental plains deserts of North Eur asia (Budyko-ratio > 3) are characterized by low species richness of m ammal (thirty to thirty-three species). Mountains (with the exception of the Ural Mountains) have significantly greater mammal species richn ess as a result of greater diversity of habitats and smaller landscape units. Significant differences in relationships of mammal species ric hness in arid or mesic regions in Eurasia and North America can be exp lained by the influence of complicated mountain condition in North Ame rican deserts (with significantly greater habitat diversity and smalle r landscape units) and by overestimation of the actual number of co-ex isting species as a result of superimposing mammalian ranges. This mus t be taken into account when attempting to correlate species richness with simple environmental descriptors, such as potential or actual eva potranspiration. Actual numbers of co-existing species from long-term studies on natural protected areas can be used to improve current know ledge regarding the relationship between spatial patterns of biodivers ity and climatic change.