Changes in soil properties of xerophytic forests in Southern Russia after anthropogenic impact

Abstract

Anthropogenic influences negatively affect the soil properties and woody vegetation in the xerophytic forests and the rare forests of the northern coastal area of the Black Sea. The study was carried out at the properties of soils in the Utrish State Nature Reserve (Russia), which was previously under the influence of anthropogenic impact. Fires, deforestation, and recreational load were selected as the prioritised types of anthropogenic impact in long-term studies with soil (Cambisols) in the Utrish State Nature Reserve, which rapidly lead to the degradation of ecosystems and biodiversity reduction. Soil samples were taken from the 0–10-cm layer in triplicate from each study site. The study site after recreational load has been investigated in 2013, 2015, 2018, 2019, and 2020. The parameters pH, organic carbon content, enzyme activity were studied. Biological properties of soils were found to be more sensitive to changes in characteristics than other soil parameters. For all the studied parameters, there was a decrease in the organic carbon content from 18% to 59% relative to the control. The highest decrease in the indicator was noted for soils after deforestation. Enzymes from the oxidase class recover faster than the hydrolases. Catalase activity for all disturbed soils decreased on average by 13%. Non-significant differences from the control were observed for soils after deforestation and fires. Inhibition of invertase activity was established in soils by an average of 52% after fires and recreational exposure, with an increase in enzyme activity of 77% observed after deforestation. The results can be used to assess effects of the anthropogenic impacts on forests. Biological indicators are good markers of the condition of disturbed soils that could be implicated to determine the prioritised anthropogenic load in the soils of xerophytic forests.