Soil Microbial Functional Diversity Responses to Different Vegetation Types in the Heilongjiang Zhongyangzhan Black-billed Capercaillie Nature Reserve

The soil microbial community is an important bioactive component of terrestrial ecosystems. Its structural and functional diversity directly affects carbon and nitrogen processes. This study aimed to investigate the variations in the functional diversity of soil microbial communities in forests with different types of vegetation. We selected three typical vegetation types, larch (LG), black birch (BD), and larch and black birch mixed (LGBD) forests, located in the Heilongjiang Zhongyangzhan Black-billed Capercaillie Nature Reserve. The Biolog-Eco microplate technology was selected to perform these analyses. Our results showed clear differences between microorganisms in the three typical forests. The average well colour development (AWCD) change rate gradually increased with incubation time. The BD type had the highest AWCD value, followed by LGBD; the LG forest type had the lowest value. The difference in the soil microbial alpha diversity index between BD and LG was significant. A principal component analysis showed that PC1 and PC2 respectively explained 62.77% and 13.3% of the variance observed. The differences in the soil microbial carbon-source utilisation patterns under different vegetation types were mainly caused by esters and carbohydrates. Redundancy analysis showed that soil microbial functional diversity was strongly affected by soil physicochemistrical properties (e.g. organic carbon, total nitrogen and pH). These results provide a reference for further exploring the relationship between forest communities and soil microbes during the process of forest succession.