Vertical variations in enzymatic activity and C:N:P stoichiometry in forest soils under the influence of different tree species

Abstract

Tree species play a crucial role in shaping soil properties, significantly influencing nutrient cycling and ecological dynamics within forest ecosystems. In this comprehensive study, we examined the influence of tree species on soil chemistry especially on C/N/P stoichiometry and enzymatic activities across soil profiles. We analyzed soil samples beneath eight distinct tree species at three vertical horizons of soil: organic (O), humus mineral (A), and mineral enrichment (B) horizons. Our study involved detailed assessment of soil carbon, nitrogen, and phosphorus contents, along with the activities of key enzymes: β-glucosidase, N-acetyl-β-glucosaminidase, and phosphatase. The study revealed pronounced vertical stratification in soil properties, significantly influenced by the tree species. General linear models (GLMs) highlighted differences in C: N:P stoichiometry and enzymatic activity across different soil horizons and among tree species. Enzymatic activity was strongly correlated with C, N and P content. The conducted research confirms the distinctiveness of coniferous and deciduous species in terms of C, N and P stoichiometry and the activity of the tested enzymes involved in the C, N and P circulation. These variations are indicative of the intricate interactions between tree species and soil processes. Our findings underscore the role of diversity of trees in modulating soil nutrient dynamics and enzyme-driven processes, which are crucial for understanding soil ecosystem functions and nutrient cycling. This study provides new insights into the role of tree species in shaping the soil environment, offering implications for forest management and conservation strategies. Taking into account the impact of individual tree species covered by the research on the soil, it is worth considering the cultivation of mixed stands.