This study was carried out to examine the interaction of enzyme activities, microbial biomass carbon, and CO2 respiration with heavy metals under different land uses in terms of quality and sustainability of the soil. There is a statistically significant positive correlation between dehydrogenase enzyme activity and Mn, Pb, Cd, and Co, while it was negative between Cr. There was a positive correlation between catalase enzyme activity and Mn and Pb and between urease and Co. The higher interaction of dehydrogenase activity with heavy metals, which is included in the endo enzyme group, has been explained as a much stronger effect of heavy metals on living microorganisms and endoenzymes than extracellular enzymes stabilized on clay minerals and organic matter. The high clay content of the soil is thought to reduce some of the negative effects of heavy metals on enzymes. The results of this study may be good indicators of enzyme activities, especially dehydrogenase, catalase, and urease, for soil health and quality, chemical degradation and restoration processes, and ecosystem functioning in soils contaminated or to be contaminated with heavy metals. It shows that the activities of these enzymes are very sensitive and can decrease rapidly in case of high concentrations of heavy metals.
Keywords: CO2; emission; heavy metals; microbial biomass carbon; principal component analysis (PCA); soil enzyme activity.
Soil health and quality, chemical degradation and restoration processes, and soils contaminated with heavy metals or potentially polluted can be good indicators of ecosystem functioning. This study was carried out with the belief that the interaction of enzymes with heavy metals in this type of soil will be revealed in detail and will shed light on such studies to be done in the future.