凋落物输入改变对亚热带两种米槠次生林土壤酶活性的影响  

Response of soil enzyme activities to litter input changes in two secondary Castanopsis carlessii forests in subtropical China

作　　者：魏翠翠[1,2,3] 刘小飞 林成芳[1,2,3] 李先锋 李艳[1,2,3] 郑裕雄 WEI Cui-Cui;LIU Xiao-Fei;LIN Cheng-Fang;LI Xian-Feng;LI Yan;ZHENG Yu-Xiong(School of Geographical Sciences,Fujian Normal University,Fuzhou,350007,Chin;State Key Laboratory of Humid Subtropical Mountain Ecology,Fuzhou,350007,Chin;and Sanming Research Station of Forest Ecosystem and Global Change,Sanming,Fujian 365000,China)

机构地区：[1]福建师范大学地理科学学院,福州350007 [2]湿润亚热带山地生态国家重点实验室培育基地,福州350007 [3]福建三明森林生态系统与全球变化研究站,福建三明365000

出　　处：《植物生态学报》2018年第6期692-702,共11页Chinese Journal of Plant Ecology

基　　金：国家自然科学基金(31770663和31500407);海峡联合基金(U1505233)~~

摘　　要：酶在土壤有机质分解中起重要作用。为深入了解全球变化背景下森林凋落物产量的改变对森林生态系统过程的影响,以亚热带米槠(Castanopsis carlesii)人促更新次生林(米槠人促林)和米槠次生林为研究对象,设置凋落物加倍(DL)、凋落物去除(NL)和对照(CT)3种处理,探讨土壤6种胞外酶活性的变化。研究结果表明:米槠次生林中土壤纤维素水解酶(CBH)、β-N-乙酰氨基葡萄糖苷酶(NAG)、酚氧化酶(PhOx)和过氧化酶(PerOx)活性高于米槠人促林,而酸性磷酸酶(AP)和β-葡萄糖苷酶(βG)活性没有差异;NL和DL处理均降低了两种不同更新方式森林土壤的AP、βG和NAG活性,CBH和PerOx活性均无显著变化,而PhOx活性仅在DL处理后降低;除NAG活性外,米槠人促林的AP、βG、PhOx活性在凋落物处理后下降的幅度均高于次生林;Pearson相关分析和冗余分析表明,土壤酶活性与土壤含水量、碳(C)、氮(N)含量和微生物生物量碳(MBC)、氮(MBN)含量显著相关。因此,凋落物输入的改变(无论增加和减少),引起了土壤含水量、C、N以及MBC和MBN含量的下降,进而可能会导致亚热带米槠次生林和米槠人促林土壤某些胞外酶(如AP、βG和NAG)活性降低。从土壤酶活性角度看,米槠次生林比米槠人促林更有利于亚热带森林生态系统C、N养分循环。Aims Enzymes play an important role in the decomposition of soil organic matter. Changes in net primary productivity in response to climate change are likely to affect litter inputs to forest soil. However, the effects of altered litter input on soil enzyme activities remain poorly understood in subtropical forests. Thus, this study is designed to find out if litter manipulation has an effect on enzymes in different subtropical Castanopsis carlessii forest. Methods Three treatments including double litter（DL）, no litter（NL） and control（CT） were installed in a secondary C. carlesii forest and a human-assisted naturally regenerated C. carlesii forest, to investigate the responses of 6 soil extracellular enzyme activities. Important findings The activities of Cellobiohydrolase（CBH）, β-1,4-N-acetylglucosaminidase（NAG）, Polyphenol oxidase（PhOx） and Peroxidase（PerOx） in the secondary C. carlesii forest were higher than those in the human-assisted naturally regenerated C. carlesii forest, while acid phosphatase（AP） and β-1,4-glucosidase（βG） activities had no significant difference between the two forests. Compared to control, both NL and DL treatments decreased the activities of AP, βG and NAG, but had no effect on the activities of CBH and PerOx, and DL treatment decreased only the activity of PhOx in two forests. Except for NAG activity, the activities of AP, βG andPerOx decreased more in the human-assisted naturally regenerated C. carlesii forest than in the secondary C. carlesii forest after litter manipulaition. Both Pearson correlation analysis and redundancy analysis showed that soil enzyme activities were significantly correlated with soil moisture content, carbon（C）, nitrogen（N）, microbial biomass carbon（MBC） and nitrogen（MBN） contents. Therefore, changes in litter input（both increase and decrease） could decrease some major soil enzyme activities such as AP, βG and NAG in both secondary and human-assisted naturally regenerated C. carlesii forests by

关 键 词：凋落物加倍 凋落物去除 土壤酶活性 米槠次生林 米槠人促更新次生林 

分 类 号：S714[农业科学—林学]