Role of Seasonality and Fire in Regulating the Enzymatic Activities in Soils Covered by Different Vegetation in a Mediterranean Area

Abstract

As they quickly respond to environmental conditions, soil enzymes, involved in nutrient cycles, are considered good indicators of soil quality. The Mediterranean area is a peculiar environment for climatic conditions and for fire frequency. Therefore, the research aimed to evaluate the role of seasonality and fire on enzymatic activities (i.e., hydrolase, dehydrogenase, and β-glucosidase) in soils covered by herbs, black locust, pine, and holm oak. In addition, the main soil abiotic properties that drive the enzymatic activities were also investigated. In order to achieve the aims, surface soils were collected in unburnt and burnt areas and characterized for water and organic matter contents, pH, concentrations of C and N, and available fractions of Al, Ca, Cu, Fe, Mg, Mn, Na, and Pb. The results highlighted that the soil enzymatic activities were mainly affected by seasonality more than by fire; in unburnt soils, their main drivers were nutrient availabilities, whereas, in burnt soils they were pH, water and organic matter contents, C and N concentrations, and both nutrient and metal availabilities. Finally, holm oak, as compared with herbs, pine, and black locust, conferred higher stability to soils that were affected by seasonality and fire.

Metal Release from Microplastics to Soil: Effects on Soil Enzymatic Activities and Spinach Production

“…As with plants, soil microorganisms are also vulnerable to the available fraction of heavy metals that affect their growth and activities [ 17 ]. In particular, many soil enzymes (such as hydrolase, dehydrogenase, β-glucosidase and urease) are used as indicators of heavy metal contamination since they quickly respond to changes of soil condition [ 18 ]. For example, Hu et al [ 19 ] proposed the use of dehydrogenase as an indicator of microbial activity in soils contaminated by heavy metals.…”