摘要
为探究人为干扰对土壤胞外酶活性及其化学计量特征的影响,并深入揭示森林生态系统养分循环的生态学过程与机制,以福建省建阳区麻沙镇受轻度干扰和重度干扰的闽楠(Phoebe bournei)林作为研究对象,采集0~10 cm土层样品,测定4种酶[β-葡萄糖苷酶(BG)、β-1,4-N-乙酰氨基葡萄糖苷酶(NAG)、亮氨酸氨基肽酶(LAP)、酸性磷酸酶(AP)]的活性、土壤理化性质及微生物生物量,运用酶化学计量比与矢量模型分析不同干扰强度下土壤胞外酶活性特征及养分限制状况。结果表明:轻度干扰样地中BG活性显著高于重度干扰(P<0.05),而LAP活性则呈相反趋势;重度干扰强度下氮获取酶(LAP)活性显著高于轻度干扰(P<0.05),而轻度干扰下土壤酶碳氮比(C∶N)和碳磷比(C∶P)更高。两种干扰强度下土壤酶矢量角度均小于45°,均呈现土壤微生物普遍受氮限制,且随干扰强度增加,矢量长度显著减小(P<0.05)。冗余分析显示,土壤微生物生物量碳、土壤养分、土壤pH值和土壤含水量是影响BG、NAG、LAP、AP活性的重要因子。随干扰强度增加,闽楠林土壤胞外酶活性特征发生显著变化,具体表现为碳获取酶活性降低、氮获取酶活性升高、酶C∶N和C∶P比下降。
To assess the impacts of human disturbance on soil extracellular enzyme activities and their stoichiometry and to further elucidate the ecological processes and mechanisms of nutrient cycling in forest ecosystems,this study selected Phoebe bournei forests under mild and severe human disturbance intensities in Jianyang,Fujian,China as the research objects.Soil samples 0-10 cm depth were collected to determine the activities of four enzymes:β-glucosidase BG,β-1,4-N-acetylglucosaminidase NAG,leucine aminopeptidase LAP,and acid phosphatase AP,along with soil physicochemical properties and microbial biomass.Enzyme stoichiometry and vector analysis were employed to characterize the enzyme activity patterns and nutrient limitations under different disturbance intensities.The results showed that BG activity was significantly higher under mild disturbance than under severe disturbance,whereas LAP activity showed the opposite trend.Severe disturbance resulted in significantly higher N-acquiring enzyme LAP activity than mild disturbance.In contrast,the enzymatic C∶N and C∶P ratios were higher under mild disturbance.Vector angles were below 45°under both disturbance intensities,indicating a consistent nitrogen N limitation on microorganisms.Moreover,the vector length decreased significantly as the disturbance intensity enhanced.Redundancy analysis identified soil microbial biomass carbon,soil nutrients,pH,and water content as key factors influencing BG,NAG,LAP,and AP activities.Increased disturbance intensity led to reduced C-acquiring enzyme activity,increased N-acquiring enzyme activity,and decreased enzymatic C[KG-*3]∶N and C∶P ratios.
作者
朱德煌
陈欣怡
刘金福
ZHU Dehuang;CHEN Xinyi;LIU Jinfu(College of Ecology and Resources Engineering,Wuyi University,Wuyishan,Fujian 354300,China;College of Forestry,Fujian Agriculture and Forestry University,Fuzhou,Fujian 350002,China;Key Laboratory of Fujian Universities for Ecology and Resource Statistics,Fuzhou,Fujian 350002,China)
出处
《森林与环境学报》
北大核心
2026年第2期123-130,共8页
Journal of Forest and Environment
基金
福建省自然科学基金项目“武夷山不同海拔梯度下‘植物-凋落物-土壤’的生态化学计量特征”(2021J05248)
武夷学院引进人才科研启动项目“武夷山山地与湿地生态系统生态化学计量及其机制研究”(YJ202103)
福建省高校生态与资源统计重点实验室开放课题项目“闽楠林生态系统的化学计量特征及其保护机制研究”(PTJH17011-5)。
关键词
闽楠
干扰
土壤
胞外酶活性
养分限制
Phoebe bournei
disturbance
soil
extracellular enzyme activities
nutrient limitation
