火烧对亚热带森林土壤微生物胞外酶化学计量的影响OA

Fire is an important disturbance factor in soil nutrient cycling in forest ecosystems.Based on soil samples from unburned control and burned plots in a subtropical forest in Shanghang County,Fujian Province,this study analyzed the stoichiometric characteristics of extracellular enzyme activities related to carbon(C),nitrogen(N),and phosphorus(P)cycling and evaluated the effects and mechanisms of fire on microbial resource allocation and nutrient limitation.The results showed that fire significantly increased the enzymatic C∶N and C∶P ratios,indicating an intensification of relative C limitation of soil microorganisms.In contrast,the enzymatic N∶P ratio significantly de-creased,suggesting aggravated relative P limitation.In control soils,microbial nutrient limitation was primarily regulated by soil nutrient stoichiometry,whereas after fire,soil biodiversity and pH be-came the key factors modulating microbial nutrient limitation.These findings provide a scientific ba-sis for subtropical forest conservation and post-fire ecological restoration.