Satellite-Derived Spatiotemporal Variations of Forest Cover in Southern Forest-Steppe, Central Russian Upland

Forest cover dynamics derived from detailed archival and recent satellite images was studied in the southern forest-steppe within Belgorodskaya Oblast, Central Russian Upland. We analyzed data from 5 sites of the total area of 1722 km(2), representative for diverse environment of the region. The forest cover increased by 31% during 1970-2014. Fragmentation of lands with forest cover was noted. Number of separate woodlands has increased by 87% and the mean size of woodland has decreased from 13.0 to 9.2 ha. Mean linear movement of the forest margin towards steppe tended to decrease from northwest to southeast. The largest advance of 34.3 m of the forest margin was found in the humid western part of the region, while it was as small as 15.0 m in dry southeast. Mean distance of forest advancement since 1970 was 24 m, as measured at 1285 study sites. The distances of forest expansion significantly differed between forest-steppe and steppe domains of Belgorodskaya Oblast. The expansion cannot be attributed to northern or southern exposition of the forested slopes of river valleys and ravines.