Assessment of the Impact of Fires on the Steppe Phytocenoses of the Russian Federation

Abstract

Steppe zone in the Orenburg region is subject to a powerful anthropogenic load. Most of the territory of the steppes is plowed, and the rest of the land is adapted for pasture or is a Deposit. In addition, fires are a serious threat to the biodiversity of the region’s ecosystems. Fires affect the phytocenosis and cause substantial conversion of plant communities. The level of exposure may vary depending on the frequency of the fire, timing and intensity. In recent years, the spread of steppe fires in Russia and their frequency have acquired an extraordinary scale. The climatic conditions of the region (dry, hot summers and long atmospheric droughts) contribute to the spread of fires in large areas. In order to trace the restoration of steppe ecosystems after a fire we have investigated the dynamics of stocks of aboveground phytomass in the 2015-2017 periods, the article considers the initial stages of the leftover post-fire changes in grass communities (Festuca valesiaca, Stipa zalesskii, Artemisia austriaca, Herbae stepposae). Studies have shown how components of above-ground phytomass (live phytomass, rags, litter) accumulate and distribute in the community after a fire. A comparison with similar unburned grasses (Stipa zalesskii, Poa transbaicalica, Herbae stepposae) community with Spiraea crenata. The change of dominant species in the phytocenosis, reduction of the total projective cover in comparison with the control was revealed.