The distinctive features of biological turnover in postagrogenic ecosystems of the south taiga and their effects on the chemical properties and biological activities of soils

A degrading plowland succession consisting of the plowland itself, lands that were fallow for 7 and 12 years, small-leaved secondary forest, and mature forest, has been investigated. The total phytomass of the ecosystem increased during postagrogenesis due to the development of plurannual wood, while the herbaceous layer phytomass decreased, especially after continuous forest had been formed. Stores of nitrogen and ash constituents derived from easily degradable plant waste were maximal in the 7-year fallow land; optimal temperature conditions and nutrient content in the soil, and high biological activity of the soil were observed at the same time point.