摘要
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)循环相关的酶活性。通过分析土壤酶计量比、矢量长度(VL)和矢量角度(VA),探究土壤微生物的能量和营养相对限制状况及其关键调控因素。结果表明:随海拔升高,β-葡糖苷酶(BG)活性呈现增加的趋势,而β-N-乙酰氨基葡糖苷酶(NAG)、亮氨酸氨基肽酶(LAP)和酸性磷酸酶(AcP)活性以及(NAG+LAP)/微生物生物量碳(MBC)和AcP/MBC则相反;酶C/N、酶C/P、酶N/P和VL随海拔升高而增加,而VA则降低,表明微生物受P限制程度在低海拔处较高,而C限制在高海拔处较高。此外,可溶性有机C和微生物生物量P是不同海拔土壤微生物能量和营养相对限制状况的关键调控因素。本研究结果可为土壤C、N、P有效性与微生物的能量和营养相对限制状况对海拔梯度的响应提供理论依据,有利于提高我们对亚热带山地森林生态系统土壤生物地球化学循环过程的理解。
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.
作者
林惠瑛
周嘉聪
曾泉鑫
孙俊
谢欢
刘苑苑
梅孔灿
吴玥
元晓春
吴君梅
苏先楚
程栋梁
陈岳民
LIN Hui-ying;ZHOU Jia-cong;ZENG Quan-xin;SUN Jun;XIE Huan;LIU Yuan-yuan;MEI Kong-can;WU Yue;YUAN Xiao-chun;WU Jun-mei;SU Xian-chu;CHENG Dong-liang;CHEN Yue-min(College of Geographical Science,Fujian Normal University/Fujian Province Key Laboratory of Subtropical Mountain Ecology,Fujian Normal University,Fuzhou 350007,China;College of Tourism,Wuyi University,Wuyishan 354300,Fujian,China)
出处
《应用生态学报》
CAS
CSCD
北大核心
2022年第1期33-41,共9页
Chinese Journal of Applied Ecology
基金
福建省自然科学基金项目(2020J01397,2020J01142)资助。
关键词
海拔梯度
土壤胞外酶
酶计量
养分限制
elevational gradient
soil extracellular enzyme
ecoenzymatic stoichiometry
nutrient limitation
