Experience of Large-Scale Analysis of the Spatial Patterns of Plain Forest Ecosystem Productivity and Biogeochemical Processes

Abstract

We considered the scale, causes, and factors of local variations of the biological productivity and heavy meals’ uptake in forest ecosystems on the example of a model site of the subtaiga area of the East European plain (Russia, Meshchera lowlands). In accordance with the principles of Russian regional landscape science, we substantiated the leading role of the relief (including relict forms) and bedrock surface morphology as the production process factors. Based on the geological history analysis, we provided a genetic typification of morphostructures with forest productivity properties. It was revealed that the most significant decrease in the growth of forest-forming species (up to 50–60% of the zonal average) is observed within the pre-Pleistocene erosion cuts, and the highest bioproductivity (up to 1.5 times higher than the average in the East European subtaiga) is confined to the buried pre-Jurassic erosion butte composed of limestone. Due to the high density of limestone (1.20–1.33 times denser than other rocks in the territory), its local projections form positive gravitational anomalies, stimulating water exchange and reducing the effect of waterlogging. We have pointed out the genetic relationship of landscape processes in the Pleistocene and Holocene and the indicator role of periglacial forms: relics of flowing thermokarst correspond to the most productive forests, while offshore bars display the lowest productivity. Lithogenetic heterogeneities determine the spatial variability of the species composition, and, accordingly, 2-6-fold fluctuations of heavy metals’ uptake are observed. The greatest potential resistance to priority toxicant—Cd—have ecosystems with maximum biological activity of tree stands and a high proportion of “humidicated” species.