Biochemiczna aktywność gleb różnych siedlisk leśnych

The aim of the study was to determine the enzymatic activity and chemical properties of soil in selected stands of different age classes on two forest site types: fresh mixed coniferous forest (BMśw) and fresh mixed deciduous forest (LMśw). The investigations were carried out in Nowe Ramuki Forest District in 2013−2015 located in the central part of Warmińsko−Mazurskie administration district Poland. In organic and humus horizons following parameters were described: acidity in 1M KCL, content of nitrogen, carbon and exchangeable alkaline cations (Na+, K+, Ca2+ and Mg2+) as well as hydrolytic acidity. Enzymatic investigation included the measurements of urease, asparaginase, acid phosphatase and dehydrogenase activity. Content of C and N, sum of base cations (S), hydrolytic acidity (Hh), cation exchange capacity (PWK), base saturation percentage were significantly higher in organic than humus horizon. Enzymatic activity was connected with the content of organic matter, what resulted in higher activity in organic than humus horizon independently of site type and stand age. The concentration of organic carbon (C), nitrogen, C/N ratio, hydrolytic acidity and cation exchange capacity was higher on BMśw than LMśw site type. Activity of urease, acid phosphatase and dehydrogenase was lower in soils of LMśw than BMśw site type. Lower enzymatic activity may suggest lower intensity of decaying process of organic matter in these soils. Significant correlations between enzymes and chemical soil parameters were found. Significant correlation between enzymatic activity and soil chemical properties shows that biochemical parameters can be used as indexes of their productivity. Investigation of biochemical reaction intensity can be complement to soil chemical studies usually used in forestry.