亚热带米槠天然林不同深度土壤胞外酶活性对隔离降雨的响应  

Response of Soil Extracellular Enzymes Activities to Throughfall Exclusion at Different Depths in a Subtropical Natural Castanopsis carlesii Forest

作　　者：曹平丽 孙思怡 卢胜旭 张锦新 刘小飞[1,2] 郭剑芬[1,2] CAO Pingli;SUN Siyi;LU Shengxu;ZHANG Jinxin;LIU Xiaofei;GUO Jianfen(Institute of Geography,Fujian Normal University.Fuzhou 350007;Key Laboratory for Humid Subtropical Eco-geographical Processes of the Ministry of Education,Fujian Normal University,Fuzhou 350007;Ocean College,Minjiang University,Fuzhou 350108)

机构地区：[1]福建师范大学地理研究所,福州350007 [2]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350007 [3]闽江学院海洋学院,福州350108

出　　处：《水土保持学报》2022年第1期205-211,共7页Journal of Soil and Water Conservation

基　　金：福建省科技厅公益类重点项目(2019R1002-4);福建省高等学校新世纪优秀人才支持计划项目(J1-1253);国家自然科学基金项目(41977090)。

摘　　要：随着全球变暖的加剧,降雨格局也在发生变化,土壤酶是森林生态系统化学过程的重要参与者,能够快速反映土壤环境的变化。因此研究亚热带土壤胞外酶活性对降水变化的响应,可有效评估气候变化对土壤有机质分解、转化的影响。以福建三明格氏栲自然保护区内的米槠天然林为研究对象,设置对照(CT)、隔离30%降雨(TE1)和隔离60%降雨(TE2)3种处理,于2020年9月对不同土层(0—10,10—20,20—40,40—60 cm)土壤进行取样,研究9年的隔离降雨对不同土层土壤酶活性的影响。结果表明:不同程度隔离降雨后,4个土层的β—葡萄糖苷酶(βG)、β—N—乙酰氨基葡萄糖苷酶(NAG)和酸性磷酸酶(AP)活性均呈下降趋势。与CT相比,TE2处理0—40 cm土壤AP、βG和NAG酶活性均显著降低(P<0.05),40—60 cm土壤AP酶活性在TE1和TE2处理中降低均较为显著。随着土层加深,3种土壤胞外酶活性均逐渐降低。冗余分析(RDA)表明,在0—10 cm土壤中,土壤含水量(SWC)、总氮(TN)和可溶性有机碳(DOC)是调控土壤胞外酶活性的主要因素,10—20 cm土壤胞外酶活性主要受控于可溶性有机碳(DOC)和铵态氮(NH _(4)^(+)—N),而可溶性有机氮(DON)和硝态氮(NO_(3)^(-)—N)是调控20—40 cm土层土壤胞外酶活性的关键因素。在40—60 cm土壤中,碳磷比(C∶P)主要影响着3种土壤胞外酶活性。可见,不同深度土壤胞外酶活性对降水减少的响应及调控因素不同。研究结果有助于进一步了解全球气候变化背景下亚热带森林土壤养分转化与循环机制。With the intensification of global warming,the rainfall pattern is also changing.Soil enzymes are the important participants in the chemical process of forest ecosystem and can quickly reflect the changes of soil environment.Therefore,studying the response of extracellular enzymes activities in subtropical soil to precipitation changes can effectively evaluate the impact of climate change on soil organic matter decomposition and transformation.In this study,the natural Castanopsis carlesii forest in Castanopsis kawakamii Nature Reserve of Sanming,Fujian Province was selected,and three treatments were set up,including control(CT),30%of throughfall excluded(TE1)and 60%of throughfall excluded(TE2).In September 2020,soil samples of different soil layers(0—10,10—20,20—40,40—60 cm)in each treatment were collected to study the effects of 9-year throughfall exclusion on soil enzymes activities.The results showed that the activities ofβ-glucosidase(βG),β-N-acetylglucosaminosidase(NAG)and acid phosphatase(AP)in the four soil layers decreased after throughfall exclusion.Compared with CT,the activities of AP,βG and NAG in 0—40 cm soil under TE2 treatment were significantly decreased(P<0.05),and the activities of AP in 40—60 cm soil under TE1 and TE2 treatments were also significantly decreased.With increasing soil layers,the activities of three extracellular enzymes decreased.Redundancy analysis(RDA)showed that soil moisture content(SWC),total nitrogen(TN)and soluble organic carbon(DOC)were the main factors regulating the activities of soil extracellular enzymes in 0—10 cm soil,while DOC and ammonium nitrogen(NH_(4)^(+)—N)in 10—20 cm,and soluble organic nitrogen(DON)and nitrate nitrogen(NO_(3)^(-)—N)in 20—40 cm.In 40—60 cm soil,the C∶P ratio mainly influenced the extracellular enzymes activities.In conclusion,the responses and regulatory factors of soil extracellular enzymes activities to the decrease of precipitation were different at different soil depths.The results of this study are helpful

关 键 词：米槠天然林 隔离降雨 土壤深度 胞外酶活性 

分 类 号：S718.5[农业科学—林学]