LANDUSE FEATURES IN A MOUNTAIN AREA AND THEIR EFFECTS ON THE PROCESS OF SYLVATISATION (STRYY DISTRICT LVIV REGION)

Abstract

The Skole District that is nowadays a part of newly established Stryy District (Lviv Region) is entirely situated within the range of the Ukrainian Carpathians. Its area encompasses the Skolivsli Beskydy and the Stryy-San Highland physiographic regions featuring a dominance of considerably high altitudes above sea level, terrain disarticulation, and afforestation. Establishing new villages alongside rural population’s natural increase and land reforms (the capitalist stage of land use (after the abolition of serfdom in 1848) and Soviet stage of land use) called for respective increase in agricultural lands. Forested lands in the Ukrainian Carpathians were the source for such an increase therefore cropland and pasture lands were emerging from deforestation. Harsh weather conditions and low soil fertility significantly impacted the further agricultural land uses in the mountainous region. However, wide-scale decline of agricultural lands occurred in the period of the collapse of the former USSR due to decline of collective and state farms. As a result of denationalization with subsequent privatization of agricultural lands there are nowadays 31 303 land owners and land users in the study area, 97,54 % of which are physical persons. At the same time, despite such remarkable figures citizens share less than a half of total lands for agriculture, residential and construction purposes, whilst the state forestry enterprises are using 51,11 % (75 173,50 ha) in total. In contrast to lowlands, animal farming and husbandry in the Skole District is held exclusively by households. In recent years local animal husbandry is experiencing the livestock decline that leads to certain reduction in the share of both hay meadows and pasturelands. Thus, from 2009 to 2016 the total area of fodder lands in the district decreased by 65 ha (ca. 0,2 % of total privately owned agricultural lands). I assume that ongoing land reform will cause further increase in fallows in the Skole District. In order to better comprehend the processes of spontaneous reforestation (sylvatisation) in a mountain region (the Pohartsi boundary, Koziova village, Stryi district, Lviv regionthe ) four study plots were selected representing the successional sequence: forest → pasture → hay meadow → arable lands. The study showed that areas that were previously used for pasture and were not plowed, are restored to their natural state much faster. These areas are characterized by satisfactory physical, physico-chemical and biotic properties. The decrease in acidity towards the neutral side is explained by an increase in the activity of catalase and urease by approximately 1.5 times. In connection with the developed grass cover, slightly higher nitrogen values were recorded in the upper soil horizon. Due to the absence of a regular annual supply to the base and replenishment of its nutrient reserves due to precipitation and waste of dead phytomass, the content of humus in the upper horizon of the base is half as much as under forest biogeocenoses. Plowing (overturning the lower horizons to the mountain, and vice versa) is a very strong anthropogenic factor, which leads to the almost complete destruction of natural vegetation on the cultivated area and a radical change in the main properties of the soil cover. According to some indicators: physical (total sparability), physico-chemical (nitrogen nitrate and ammonia), biotic (urease, catalase, biomass of microorganisms) in the upper humus horizons were even somewhat close to anthropogenically unaltered ecosystems. However, the changes in the indicators of the density of the soil structure and its solid phase corresponded to the depth of plowing. And the humus content was several times lower than under forest biogeocenoses. Areas that were not plowed in the past are restored due to the main rock of the region Picea abies (L.) Karst.. Areas that were devastated in the past are recovering much more slowly. Such areas begin to overgrow with Alnus incana (L.) Moench., Rosa canina L., Bеtula and others Key words: land use; land owners and land users; fallows; agricultural lands; mountainous region; Skolivski Beskydy.