UDC 581.5;58.02

Dusaeva G.Kh., Kalmykova O.G. LONG-TERM DYNAMICS OF STOCKS OF LIVING ABOVE-GROUND PHYTOMASS OF STEPPE PHYTOCENOSES AFTER A WILD FIRE (ON THE EXAMPLE OF THE BURTINSKAYA STEPPE OF THE ORENBURG NATURE RESERVE) // Arid Ecosystems. 2023. Vol. 29. № 2 (95). P. 67-76. | PDF

In recent years the area and frequency of wild fires was growing catastrophically in the steppes of the arid regions of the Russian Federation. The fires destroy the above-ground part of phytocenoses, significantly reducing the stocks of above-ground phytomass and productivity of communities, and changing the structure and composition of steppe phytocenoses. The purpose of our work was to study the effect of the pyrogenic factor on the stocks of living above-ground phytomass, and determine the time required for its full recovery. After a wild fire in 2015, 6 monitoring sites were established in the Burtinskaya Steppe of the Orenburg Nature Reserve. Each site included a control (intact) plot and a burned plot. Standard geobotanical methods were used along with mowing to identify the features and dynamics of the stocks of living above-ground phytomass. The studies were carried out in 2015-2020. As a result, we found out that the reserves of phytomass (g/m²) can reach the value of the control communities in the 2^nd year of the study. The seasonal dynamics of live phytomass starting from the 3^rd to 4^th year after burning are mostly affected by the community composition and type instead of the pyrogenic factor. During the entire period of our study, the proportion of live phytomass stocks of burned communities reached the values of control phytocenoses. However, it was always higher than the control values, which indicates incomplete restoration of the structure of the above-ground phytomass of the burnt area.

Keywords: steppe fires, stocks of living above-ground phytomass, seasonal dynamics, year-to-year dynamics, protected areas, revegetation, Orenburg region.

Financing. The work was carried out for the state task of the Steppe Institute of the Ural Branch of the Russian Academy of Sciences “Problems of Steppe Nature Management in the Conditions of Modern Challenges: Optimization of the Interaction of Natural and Socio-economic Systems” (Project No. GR AAAA-A21-121011190016-1).

DOI: 10.24412/1993-3916-2023-2-67-76

EDN: HKXEXJ