Bioindication of the Forest Ecosystems State of the South Baikal Region with the Use of Herbaceous Mesophytes Characteristics

Analysis of biometric studies data of environmentally-sensitive species of Ranunculaceae family in relation to the studies of the influence of long-term technogenic emission in the city of Baikalsk on the natural resistibility factors of plants is given. It has been proved that it is possible to use the state of cenosis populations of herbaceous mesophyte Thalictrum minus L. as a bioindicator to estimate pollution of forest ecosystems of the South Baikal Region. A change of 15-30 % of species habitus and reduction in the duration of certain ontogenetic states up to 3-15 years is registered according to degradation of environmental performance indices of a specific area. Species of average and low vitality form decreasing populations. Their dynamics leads to the change of vitality range and reduction in indicator species in the areas of high aerotechnogenic environmental stress. Statistical analysis of factors influencing formation of plants habitus has shown that the most significant ones are crown thinning, projective cover of grass stand and percentage of organic substance in the soil. Non-linear regression modeling of environmental factors influence on habitus development of Thalictrum mesophytes makes it possible to prognosticate the behavior of their cenosis parameters in conditions of environmental stress accurately.