ОПЫТ ЛАНДШАФТНОГО АНАЛИЗА ПРОСТРАНСТВЕННЫХ ЗАКОНОМЕРНОСТЕЙ ПРОДУКТИВНОСТИ ЗОНАЛЬНЫХ ЭКОСИСТЕМ ЮЖНОЙ МЕЩЕРЫ

Abstract

The extent, causes and factors of local variations in biological productivity of zonal forest ecosystems are examined on a case study of the model area of subtaiga of the East European Plain (Ryazan oblast, the Meshchera lowland). It is established that in conditions of wide distribution of Pleistocene sands and lowcontrast relief of the Meshchera lowland the main limiting factor of the biological productivity is waterlogging. In according with the classical concept of Russian regional landscape science (school of N.A. Solntsev), the leading role of relief (including the relict relief) and morphology of the bedrock surface in the biological productivity and dynamics of moisture is proved. It is noted that the dynamics of moisture in the landscape depends not only on the relief but also on the characteristics of the buried bedrock. Based on the analysis of geological history the genetic typification of morphostructures with the specific features of forest productivity is performed. It is identified that the most significant decline in biological productivity of tree species (up to 50–60% of zonal average) is observed in the contours of ancient erosive valleys. The regional maximum of forest productivity (up to 1.5 times higher than the average forest productivity in subtaiga of the East European Plain) is observed on the top of the buried pre-Jurassic erosive massif (outliers), composed of limestone. Due to the high density of limestone (1.20–1.33 times higher than that of other bedrock, composing the territory), its local protrusions form a positive gravitational anomaly that stimulates dynamics of moisture and reduces the impact of waterlogging. The genetic link of landscape processes in the Pleistocene and Holocene and indicator role of the periglacial forms of morphosculpture are identified. The most productive forests correspond to relicts of polygonal forms and the flowing thermokarst, minimum productivity correspond to areal shape and shore bars. It is established that the efficiency of drainage melioration depends on the landscape structure and most visible near the top of the buried pre-Jurassic erosive massif, composed of limestone (growth of productivity of hydromorphic ecosystems up to 20%). The effect of drainage melioration in the contours of the ancient erosive valleys is insignificant.