Reforestation in Postagricultural Areas of Western Transbaikalia.

The article establishes the tendencies of forest formation in fallow lands of different ages, currently used as rangelands, in postagricultural areas of Western Transbaikalia. Assessments of the nature of the restorative dynamics of forests in fallow lands extensively reference the typological and species composition of phytocenoses of the surrounding areas that have never been used for tilling. It is established that herbaceous communities currently emerging in fallow lands and steppe areas include tree species such as Scots pine (Pinus sylvestris L.), more rarely Siberian larch (Larix sibirica Ledeb.), and sometimes Siberian elm (Ulmus pumila L.). It has been determined that, once removed from intensive pasture rotation, plant communities gradually restore a layered structure and show an increase in the species diversity of plants and in their abundance in communities. At the same time, it is noted that pine is actively advancing into herbaceous (steppe) communities of plant species typical of the forest–steppe and steppe. It has been found that the age composition of pine specimen varies from 2–5-year-old individuals to 20–25-year-old trees growing in isolated groups in fallow lands throughout the study area. It is noted that areas of fallow lands that are adjacent to a closed forest stand tend to have a fairly closed undergrowth, regardless of orographic features of the territory. The ground cover of such groupings is noted to have a significant presence of plant species characteristic of zonal light coniferous forests. That is likely to indicate an early stage of formation of zonal-type light coniferous taiga. A restraining factor in the development of forests in fallow and steppe lands in the study region is the potential increase in anthropogenic influences, mainly grazing regimes, due to an increased number of farms. Human activity in the area often involves periodic anthropogenic fires deliberately set in order to preserve rangelands. Pine undergrowth is also simply felled, both on fallow lands and in adjacent territories. That is, in many respects, a crucial factor for the possibility of formation and development of forests on postagricultural territories in the near future. [ABSTRACT FROM AUTHOR]