Variations in soil enzyme stoichiometry and microbial nutrient limitations in Camellia oleifera plantations with different ages
The alteration of stand age instigates modifiications in soil properties and microbial communities.Under-standing the impacts of stand age on soil enzyme stoichiometry and microbial nutrient limitations in Camellia oleifera plantation is crucial for nutrient management.Taking C.oleifera plantation across four age groups(＜10 a,15-25 a,30-50 a,＞60 a)in a subtropical red soil region as test objects,we examined the response of soil enzyme stoi-chiometry and microbial nutrient limitations to change in stand age and analyzed the pathways for such responses.The results showed that,compared to that of stand age＜10 a,enzyme C∶N in the 15-25 a was increased and enzyme N∶P was significantly reduced.Microbial biomass carbon(MBC),microbial biomass nitrogen(MBN),and microbial biomass phosphorus(MBP)exhibited a trend of initially decreasing and then increasing with stand age.MBN and MBN:MBP were significantly higher in the＜10 a compared to that in the 30-50 a.MBC∶MBN was significantly higher in the 30-50 a and＞60 a compared to the＜10 a and 15-25 a.Results of redundancy analysis revealed that soil nutrients,microbial biomass and their stoichiometry explained 92.4％of the variations in enzyme stoichiometry.Partial least squares path modeling(PLS-PM)results demonstrated that soil organic carbon(SOC)had a positive effect on microbial C limitation;MBN,MBN∶MBP,MBC∶MBP,SOC,and total nitrogen had a nega-tive overall effect on microbial P limitation,whereas soil C∶N had a positive overall effect on microbial P limitation.There was a significant positive correlation between microbial C and P limitations.With increasing stand age,microbial nutrient limitation shifted from N and P limitation(＜10a)to C and P limitation(15-25 a,30-50 a,＞60 a).
stand ageCamellia oleiferaenzyme stoichiometrynutrient limitation
万方数据
维普
