Monitoring assessment of the state of conservation area is a relevant and important direction in ecology. However, not all parameters of the ecological balance are checked by state services. The wide scale of specially protected areas also makes it difficult to analyze them in detail by all indicators. Therefore, it is significant to conduct a comprehensive study of such sites locally, taking into account the diversity of environmental sustainability indicators. The paper analyzes the biological diversity of flora within one of the reserves of the Belgorod region, with an emphasis on the state of tree species. The morphological assessment of the discovered species and their ecological characteristics are given. The influence of the industrial zone of the adjacent territories on the vegetation of the reserve and the microbial equilibrium of the soil cover was evaluated. In general, the ecological state of the flora is assessed as good; the microbial composition corresponds to the typical for chernozem soils. At the same time, recommendations are given for further monitoring of biodiversity indicators in this area, in order to maintain the ecological balance, preserve the species composition of vegetation and the diversity of the soil microbial community.