Elucidating the evolution of small mammal populations and communities in agrolandscape is of great importance for determining the adaptation of species to the conditions existing in various ecosystems. The research aimed to analyse the evolution of small mammal community structure, diversity and population parameters in model species in different ecosystems. The research included forest ecosystems and agrocenoses at the “Horăşti”, “Rezeni”, “Plaiul Fagului” stations in the central part of the Republic. Relative density was determined for numerical evaluation. Species, sex, age, morphological indices, physiological and reproductive status were recorded. It was determined that the desertification process in the summer of the year preceding the depression phase had a negative influence on the species of small herbivorous mammals. In spring, a decrease in relative density was recorded, especially in forest ecosystems. Communities with a relative density of 10-14% were reported in the ecotone with the blackthorn subarboretum and 3-4% in the forest ecotone with agricultural stations. In grassland fields the relative density is 8-12% in June. In forest ecosystems the dominant species is A.flavicollis (45%), and in agro-forests A.sylvaticus (62%). 12 species of rodents and 5 species of insectivores were recorded in autumn. The highest diversity was found in ecosystems near water bodies (H'=2.27), followed by forest ecosystems (1.82), forage crops (1.57) and grassland crops (1.1). There was a deep numerical depression in microtine populations in spring, with densities in forage crops being 1-2 individuals per hectare. Following the autumn rains and the intense growth of forage crops the density increased to 5-10 colonies/ha. In recent years, the dominance of the woodland species A.flavicollis and C.glareolus, but also of the species Mus spicilegus has decreased because of desertification. The negative trend is conditioned by the climate factor, which influences the development of herbaceous plants – the food source of these species. At the same time, the number of myophagous predators has increased significantly.