Pyrogenous transformations of steppe landscapes in the south-east of the Russian plain (natural parks in Volgograd region as a case study)

Abstract

For a long time fires have been and still are one of the powerful factors for transforming steppe landscapes. The current condition and pyrogenous transformations of geosystems in the south-east of the Russian Plain were examined. The following methods of field complex landscape research were used, such as semi-portable methods of “key sites”, of crop (quadrat) areas and others. The article focuses on the conclusions about the pyrogenous transformations of geosystems drawn on the basis of long-term field observation on the territory of the Donskoy natural park and the Elton natural park of Volgograd Region. Monitoring has revealed that pyrogenous transformations of geosystems appear to pose a serious threat to biological and landscape diversity of steppe. Under the influence of fire, self-regulation processes in steppe geosystems slow down and resistance to external influence reduces. The structure simplifies, the homogeneity of vegetation cover increases, grass stand and overall projective cover decreases, wood-shrub vegetation dies out. The colourful aspects of the steppe are vaguely displayed. For the long term (up to 3-5 years) biological productivity of geosystems considerably reduces from 1.5 to 3 times. The upper layer of humus burns out, soil fertility decreases and aridization of local pyrogenous geosystems increases. Evaporation speeds up, soil humidity deficit goes up, underground water level goes down, springs run dry. Wind and water erosion processes are being activated. Fires destroy sites of reproduction, recreation and feeding for animals and also habitats of rare and endangered species. Pyrogenic transformation is the most serious real threat to the biological and landscape diversity of the steppes.