Biological indicators of soil degradation in the context of global climate change

Abstract

The article discusses the pressing issue of soil degradation in the context of global climate change, which is currently becoming critical for ensuring environmental and food security. Soil resources are the basis for the functioning of agroecosystems, but under the influence of rising temperatures, frequent droughts, erosion processes, and intensified land use, there is a significant decrease in their biological activity and ability to self-regenerate. Particular attention is paid to the role of biological indicators as a sensitive and integral system for assessing the ecological state of soils, reflecting the response of living components of the soil ecosystem to changes in climatic conditions. The aim of the study is to establish a relationship between the aridity gradient and key bioindicators of soil health in different natural and climatic zones of Ukraine (Polissya, Forest-Steppe, Steppe). To this end, we analyzed indicators of microbial biomass carbon (MBC), enzymatic activity (dehydrogenase, phosphatase), specific respiration of microbiota (qCO2), soil invertebrate structure, and the ratio of physicochemical properties. The results showed a clear zonal trend: with increasing aridity, there is a decrease in microbial biomass, enzymatic activity, and earthworm abundance, while qCO2 increases, indicating an increased load on the microbial system. In the Polissya zone, biological activity remains consistently high due to the temperate climate and high humidity. The forest-steppe zone is characterized by seasonal variability in indicators, in particular a decrease in dehydrogenase activity in the summer due to moisture deficiency. The most pronounced suppression of biological activity is observed in the Steppe, where high temperatures and low precipitation create stressful conditions for soil biota. This proves that the biological properties of soil are among the most sensitive indicators of degradation, reacting faster than physicochemical parameters. The results of our research confirm that biological indicators are an effective tool for comprehensive assessment of soil condition, are sensitive to climate change, and can serve as a basis for developing adaptive strategies for sustainable agriculture.а