Ecological and biological studies in the haplic chernozems pacnic soils area in the Central Caucasus (Kabardino-Balkaria)

Abstract

The northern macroslope of the Central Caucasus and adjacent areas of the Middle Ciscaucasia belong to the Northeast Caucasian (semi-desert) type of vertical zonation. This type, which includes terskiy and elbrusskiy variants of vertical zonation, differs from the Northwest Caucasian vertical zonation by general xerophytization of landscapes. The Haplic Chernozems Pacnic soils of Kabardino-Balkaria formed within steppe zone of mentioned variants are almost entirely involved in agricultural use; natural ecosystems with characteristic species composition of natural vegetation and mesofauna were preserved only in small areas inconvenient for arable activity. Characteristics of the current ecological-biological state of the steppe ecosystem components from the Haplic Chernozems soils area (soil — vegetation — earthworms) is given. The values of synecological indices (Shannon’s, Simpson’s, Pielou’s, Hartley’s, and integral) characterize high floristic and phytocenosis diversity, and synantropization indices correspond to average levels. Earthworms are in abundance and represent the largest part of the mass of soil organisms in species composition, which corresponds to steppe zonal conditions and testifies to the dominance of the saprotrophic complex. The correlation and factor analysis by the principal components method shows wide ranges of interdependence in functioning of ecosystems components: between diversity of biotic communities and biological properties (humus content, microbial biomass carbon contents (Cmic), intensity of microbial respiration, enzymatic activity) and physicochemical properties (pH of soil solution, field moisture, soil density) of Haplic Chernozems.