THE IMPACT OF REFORESTATION ON PHYSICAL AND HYDROPHYSICAL PROPERTIES OF SOILS OF THE FALLOW LANDS (SKOLIVSKI BESKYDY, THE UKRAINIAN CARPATHIANS)
Authors: Lenevych Oksana , Rybalka Inna 
Published: February 2023

The article tackles the impacts of anthropogenic load on the physical and hydrophysical soil properties. In order to better comprehend the processes of spontaneous sylvatisation in a mountain region (the Pohartsi boundary, Koziova village, the Skolivski Beskydy physiographic region) four study plots were selected representing the successional sequence: forest → pasture → hay meadow → arable lands. Land patches that were affected the least by anthropogenic load restored faster to their natural baseline conditions. Tilling appeared to retardate restoration processes, however those anyway took place. Proper functioning of arable land patches may be facilitated by continuous land care actions (i.e. ploughing or mowing).We found that soil bulking density in arable lands increased in upper soil horizons compared to forest ecosystems. Such an increase is caused by mechanical turning upper soil horizons up down and vice versa, for lower horizons. In pasture lands, upper soil horizons are trampled down by livestock. This leads to lower water permeability of soils: increase in soil bulk density from 0.79 to 1.15 g•cm-3 resulted in a decrease of water permeability by 75 %. In forested lands, values of water permeability similar to those in arable lands (0.55 mm•min⁻¹) are usually observed along the walking trails and in wood trilling plots. On the land patches with scarce herbaceous cover erosion processes are emerging. The latter is especially dangerous for arable land patches causing extra leak of soil nutrients and thus soil depletion. In order to further exploitation soils in such patches need additional fertilizing. As agricultural load diminishes soil upper horizons restore. Restoration occurs through prolonged freezing and thawing cycles during the cold (autumn-winter-spring) season. Another path for soil physical properties restoration is associated with penetration of plant fine roots that loosen the soil. Increase of total sparing indices is observed, as well. For upper horizons of restored soil it is assessed as “intermediate” (62,00 ‒ 65,35 %) whilst for arable land patches it is significantly lower (54,90 %). Soil bulk density gradually decreased along soil profiles and study plots. In forested patches it reached minimum (2,28 g•cm⁻³) and in arable land patches – maximum (2.55 g•cm⁻³) values, which did not change upon termination of anthropogenic load. Significant changes were observed for the field humidity indices. These varied both spatially, along soil profiles, and temporarily, by seasons. Lack of herbaceous vegetation caused over-drying in upper soil horizons. At the same time in lower horizons field humidity increased. Upper soil horizons in forested patches undergo the least changes due to the presence of thick forest floor. We conclude that major indicators of agricultural load within a soil profile are soil bulk density, water permeability and total sparing. Such indicators as the solid phase density and field humidity are of additional value.
Key words: reforestation; soil bulk density; water permeability; soil profile; arable lands; pastures; Skolivski Beskydy.