Comparative role of snags and stumps in promoting biological diversity—a case study from a mountain silver fir (Abies alba Mill.) forest

Abstract Key message Differences in chemical properties and enzymatic activity between silver fir (Abies alba Mill.) stumps and snags in Polish mountain forests highlight their different effects on nutrient cycling. Our research underscores the significant differences in microbial activity between silver fir stumps and snags. Context Stumps, as low fragments of tree trunks in contact with the soil, have different properties compared to snags, which have consequences for shaping biological diversity. Aims This research aimed to determine the properties of decaying wood in stumps and snags, analyse the number and diversity of microorganisms involved in decomposition, and determine their relationships with the wood’s physicochemical properties. This is a case study from a mountain silver fir (Abies alba Mill.) forest in Poland. Methods In the Babiogórski National Park, the study measured pH, carbon, nitrogen, phosphorus, lignin content, and enzymatic activity in wood samples. Fifteen stumps and fifteen snags of silver fir were designated for this research. The selection of stumps and snags was based on the degree of decomposition and their definitions. The diversity and number of microorganisms participating in wood decomposition were also assessed. Results Three out of four tested enzymes showed significantly higher activity in snag wood samples than in stumps. The analysis of bacterial and fungal diversity revealed notable differences between snags and stumps, with significant variations in a number of bacterial taxa. Conclusion Our research reveals notable differences in microbial activity between wood types in silver fir within a stand in the Polish mountains, highlighting their role in nutrient cycling and the creation of diverse habitats at this specific site.