Soil microbial metabolic diversity and its influencing factors in Wudalianchi volcanoic groups

The forest soils developed from volcanic parent material culture the soil microbial community with unique structure and function.By selecting the forest soils from the north and south slopes of Wudalianchi volcanoes and using Biolog-ECO microplate technique and space-for-time substitution method, we investigated the metabolic diversity of the soil microbial carbon source, and analyzed the soil physical and chemical properties with an aim to find out the influencing factors on the volcanic ecosystems.The results showed that the soil microbial community diversity differed significantly among different geochronological volcanoes.The average well color development(AWCD)-reflecting soil microbial activity and functional diversity, increased with the incubation time.The soil AWCD on the south slope increased with soil development stages, while that on the north slope was not significantly different.The exponential rate (P value) and asymptote (K value) of carbon source significantly differed between the north and the south slope.Principal component analysis identified that two principal component factors of the south slope explained 80.85% and 12.54% of the variance, respectively.Differences in the utilization of carbon sources by the soil microbial communities from different sampling sites were mainly caused by carbohydrates (CH) and esters (ES), which explained 64.93% of the total variance.The two principal component factors of the north slope explained 70.13% and 19.77% of the variance, respectively.Differences in the utilization of carbon sources by the soil microbial communities from different sampling sites were mainly caused by carbohydrates with phosphate rest (CH.P) and esters (ES), which explained 80.41% of the total variance.Results of redundancy analysis (RDA) suggested that the soil available phosphorus, total organic carbon, NH₄⁺-N, C∶N, N∶P and pH significantly affected the microbial carbon source metabolic types and functional diversity.The study provides a reference for further exploring the driving mechanisms of soil microbial functional diversity evolution during the soil development.