土壤酶计量揭示了武夷山黄山松林土壤微生物沿海拔梯度的碳磷限制变化

了解土壤胞外酶活性和酶计量的变化对评估山地生态系统土壤养分有效性和微生物的营养限制状况具有重要意义.然而,亚热带山地森林土壤微生物的营养限制状况对海拔梯度变化的响应及其驱动因素尚不清楚.本研究以武夷山不同海拔(1200～2000 m)黄山松林为对象,测定了土壤基本性质、微生物生物量以及与碳(C)、氮(N)、磷(P)循环...

Soil enzyme stoichiometry revealed the changes of soil microbial carbon and phosphorus limitation along an elevational gradient in a Pinus taiwanensis forest of Wuyi Mountains,Southeast China

Understanding changes in soil enzyme activities and ecoenzymatic stoichiometry is important for assessing soil nutrient availability and microbial nutrient limitation in mountain ecosystems.However,the variations of soil microbial nutrient limitation across elevational gradients and its driving factors in subtropical mountain forests are still unclear.In this study,we measured soil properties,microbial biomass,and enzyme activities related to carbon(C),nitrogen(N),and phosphorus(P) cycling in Pinus taiwanensis forests at different altitudes of Wuyi Mountains.By analyzing the enzyme stoichiometric ratio,vector length(VL),and vector angle(VA),the relative energy and nutrient limitation of soil microorganisms and its key regulatory factors were explored.The results showed that β-glucosaminidase(BG) activities increased along the elevational gradient,while the activities of β-N-acetyl glucosaminidase(NAG),leucine aminopeptidase(LAP),acid phosphatase(AcP) and(NAG+LAP)/microbial biomass carbon(MBC) and AcP/MBC showed the opposite trend.Enzyme C/N,enzyme C/P,enzyme N/P,and VL were enhanced with increasing elevation,while VA decreased,indicating a higher degree of microbial P limitation at low elevation and higher C limitation at high elevation.In addition,our results suggested that dissolved organic carbon and microbial biomass phosphorus are critical factors affecting the relative energy and nutrient limitation of soil microorganisms at different elevations.The results would provide a theoretical basis for the responses of soil carbon,nitrogen,and phosphorus availability as well as the relative limitation of microbial energy and nutrition to elevational gradients,and improve our understanding of soil biogeochemical cycle process in subtropical montane forest ecosystems.