Abstract:
Objective Soil microbial biomass carbon is the most active component of soil organic matter. Studying the microbial biomass carbon in the rhizosphere soil is of great significance.
Methods The study took Ma’an Forest Park in Wuhan City as the research object, and four different plant types (trees, small trees, shrubs, and herbs) were selected to randomly set up 33 sampling points to study the main drivers of the distribution characteristics of rhizosphere soil microbial mass carbon in different plant communities.
Results ① Soil microbial biomass carbon was significantly different in the plant rhizosphere of different plant communities. The fluctuation range of soil microbial biomass carbon in the plant rhizosphere was 270.76 ~ 908.44 mg/kg. ② Soil microbial biomass carbon was significantly and positively correlated with soil organic carbon (r = 0.662, p < 0.01), inorganic nitrogen (r = 0.510, p < 0.01), carbon−to−phosphorus ratio (r = 0.519, p < 0.01), ammonium nitrogen (r = 0.355, p < 0.01), and nitrate nitrogen (r = 0.485, p < 0.01), while it was significantly and negatively correlated with soil quick−acting phosphorus (r =− 0.134, p < 0.05). ③ The variation of soil microbial biomass entropy carbon in the rhizosphere of different plant communities ranged from 1% to 4%, among which the rhizosphere of the Dryopteris fuscipes C. Chr. was the highest, and that of the osmanthus sp was the lowest. ④ Soil organic carbon, carbon to phosphorus ratio and inorganic carbon were the main factors affecting soil microbial biomass carbon, while carbon to nitrogen ratio (36.36%, p < 0.01) and organic carbon (24.42%, p < 0.05) were the key determinants of entropic carbon content of soil microbial biomass.
Conclusion Soil carbon to nitrogen ratio and organic carbon were the main influencing factors of soil microbial biomass entropy carbon. There were significant differences between the soil microbial biomass carbon in the inter−root soils of different plants, compared to the Dryopteris fuscipes C. Chr, which had the highest inter−root soil microbial carbon sequestration capacity.