Biodiversity ensures ecological stability of ecosystems, maintaining a constant cycle of substance, energy and information, which ensures restoration of natural resources of the biosphere. Ecologists believe that the planet is experiencing an era of the sixth mass extinction of biota, large since the late Permian and Cretaceous periods. The actuality of our research is caused by need of definition of the main ecological factors’ impoverishment of biota species in Ukraine. This problem is not sufficiently investigated. The effects of different groups of environmental factors on flora and fauna were determined by calculating RDB-index. The results showed that the main cause of biodiversity depletion is human activities that lead to the destruction of ecological niches. The introduction of environmental biodiversity conservation measures may slow the degradation of the biosphere
anthropogenic pressure, biodiversity, red-book species, RDB-index