Species abundance distributions: investigation of adaptation mechanisms of plant communities

The adaptive capacity of ecosystems is a key to maintaining ecosystem functions and preserving biodiversity at all levels. The research was carried out in the western Southern Ural low-hill terrains (Russia). We analyzed distributions of above-ground biomass of herb layer species in the primary spruce, long-term secondary birch 20-35-year forests, stable-term secondary 20-year aspen forests. Species abundance distributions (SAD) analysis allowed us to study the species diversity and the species structure of communities, to understand the mechanism of adaptation of the plant community to disturbance and the role of species biodiversity in this process. It became clear that only with sufficient species diversity can SAD be maintained stable, and the adaptive potential and resistance of plant communities to external influences can be preserved. In General, the SAD analysis can be considered useful and informative for studying the adaptation of plant communities. In addition, it is universal and can be applied to any terrestrial and aquatic ecosystems. SAD can also help in designing artificial plant communities with increased resilience and high ecosystem functions.