林火干扰下亚热带森林土壤胞外酶化学计量特征  

Extracellular Enzyme Stoichiometric Characteristics of Subtropical Forest Soil under Forest Fire Disturbance

作　　者：郭琦玲 王建青 毛娇艳 孙嘉雯 黄雨晴 施秀珍 GUO Qiling;WANG Jianqing;MAO Jiaoyan;SUN Jiawen;HUANG Yuqing;SHI Xiuzhen(Institute of Geography,Fujian Normal University,Fuzhou 350117,China;School of Geographical Sciences,School of Carbon Neutrality Future Technology,Fujian Normal University,Fuzhou 350117,China;Key Laboratory for Humid Subtropical Eco-Geographical Processes of the Ministry of Education,Fujian Normal University,Fuzhou 350117,China)

机构地区：[1]福建师范大学地理研究所,福州350117 [2]福建师范大学地理科学学院碳中和未来技术学院,福州350117 [3]福建师范大学湿润亚热带生态-地理过程教育部重点实验室,福州350117

出　　处：《水土保持学报》2025年第1期94-101,共8页Journal of Soil and Water Conservation

基　　金：国家自然科学基金面上项目(32271679);福建省自然科学基金项目(2023R1002004,2024J09029)。

摘　　要：[目的]森林火灾作为亚热带森林生态系统主要的自然和人为干扰过程,严重影响土壤生物化学循环过程。为明确土壤胞外酶活性计量特征对林火干扰后恢复过程的响应。[方法]以亚热带次生林林火干扰后不同恢复阶段的土壤为研究对象,采用空间替代时间序列的方法选取7个次生林恢复阶段的亚热带森林土壤,并将其分为老龄林(60~70 a)、中龄林(30~40 a)和幼龄林(<20 a),通过测定土壤碳(C)、氮(N)、磷(P)相关的转化酶活性,揭示林火干扰下亚热带森林土壤胞外酶活性及其化学计量特征的演替规律。[结果]土壤纤维素水解酶(CBH)和β-N-乙酰氨基葡萄糖苷酶(NAG)活性随演替时间显著增加,其他酶活性无显著增加。相关性分析和冗余分析发现,土壤C、N质量分数是影响土壤胞外酶活性变化的关键因子。此外,幼龄林、中龄林和老龄林土壤胞外酶C、N、P计量比分别为1∶0.94∶1.53、1∶1.02∶1.63、1∶0.99∶1.47,表明亚热带地区森林土壤微生物生长受到P限制,且随着林火干扰后恢复年限增加逐渐改善。[结论]林火干扰后森林土壤N转化相关胞外酶活性随恢复时间呈递增趋势,土壤胞外酶化学计量逐渐趋于稳定,表明亚热带森林土壤健康状况随着林火干扰恢复过程逐渐改善。[Objective]Forest fire,as the primary natural and human-induced disturbance in subtropical forests,seriously affects the soil biochemical cycle.We aimed to clarify the response of soil extracellular enzyme activities to the restoration process following forest fire disturbance.[Methods]We investigated the soils of subtropical secondary forests at different stages of recovery following forest fire disturbances.Subtropical forest soils at seven stages of restoration were analyzed using a spatial substitution time series approach.The forests were categorized into three age groups,including old forests(60—70 years),middle-aged forests(30—40 years),and young forests(<20 years).We aimed to reveal the succession patterns of extracellular enzyme activities and their stoichiometric characteristics following forest fire disturbances by measuring invertase activities related to soil carbon(C),nitrogen(N),and phosphorus(P)in subtropical forest soils.[Results]The activities of soil cellulose hydrolase(CBH)andβ-N-acetylglucosaminidase(NAG)increased significantly with forest stand age,but the activities of other extracellular enzymes did not increase significantly with stand age.Correlation analysis and redundancy analysis showed that soil C and N contents were the key factors affecting the change of soil extracellular enzyme activities.In addition,the ratios of soil extracellular enzyme C,N and P were 1∶0.94∶1.53,1∶1.02∶1.63 and 1∶0.99∶1.47 in young,middle and old forests,respectively,indicating that soil microorganisms in subtropical forest was limited by P,but such P-limitation was improved gradually with forest stand age following forest fire disturbance.[Conclusion]The extracellular enzyme activities related to soil N transformation increased with forest stand age following forest fire disturbances in subtropical forest soils.The stoichiometric characteristics of soil extracellular enzyme gradually tended to be stable,indicating that soil health was progressively improved during the restoration process fol

关 键 词：土壤酶活性 亚热带森林 森林土壤 森林演替 

分 类 号：S714.3[农业科学—林学]