Restoration of agroecosystems in the Republic of Tyva

Abstract

Until 1995, a special study of the flora and vegetation of Tuva agroecosystems was not carried out. This work is devoted to the research of features of overgrowth of abandoned arable land, species composition of vegetation, productivity, stages of healing and their duration, prospects of their use as forage lands. Purpose. To determine the main trends of fallow ecosystems in the course of succession: changes in the species composition of phytocenoses, a set of dominant species, ecological groups of plants, the structure of plant matter and primary products in different edaphic conditions, but in the same climatic zone. Methods. For the study of each succession, key sites on the initial (control) and successional ecosystems were selected, where changes in the species composition of communities, the composition of dominants, phytomass stocks and its structure were studied. The studies were conducted in the period 1997-2018. Results. In the sharply continental climate of Tuva, the development of agriculture without irrigation has not justified itself. In the 50-60 years of the last century there were periods of mass development of virgin lands. In the early 1990s, the area of land cultivated for cultivation began to decline sharply. It is shown that the fallow succession proceeds naturally and synchronously. Summary. In arid conditions of Tuva, the initial stage of succession (0-4 years) is weeds. The first intermediate stage (4-7 years) is marked on all deposits by the absolute dominance of wheatgrass and the appearance of dominants characteristic of a certain type of steppes. The second intermediate stage (7-11 years) is characterized in that all deposits are dominated by species of the original indigenous steppes. The late stage (11-20 years) is the phase of formation of terminal communities with characteristic sets of species for each steppe, including the dominant ones.