间歇性溪流米槠凋落叶分解过程胞外酶活性动态  

Dynamics of extracellular enzyme activities during the decomposition of Castanopsis carlesii leaf litter in intermittent streams

作　　者：朱玲 魏文涛 吴若冰 郭鸿蓉 张潇月 王定一 吴福忠 ZHU Ling;WEI Wentao;WU Ruobing;GUO Hongrong;ZHANG Xiaoyue;WANG Dingyi;WU Fuzhong(Key Laboratory for Humid Subtropical Eco-Geographical Processes of the Ministry of Education,School of Geographical Sciences,Fujian Normal University,Fuzhou 350007,China)

机构地区：[1]福建师范大学地理科学学院,湿润亚热带生态-地理过程教育部重点实验室,福州350007

出　　处：《生态学报》2023年第6期2535-2545,共11页Acta Ecologica Sinica

基　　金：国家自然科学基金青年项目(32001965);国家自然科学基金面上项目(32171641)。

摘　　要：以米槠(Castanopsis carlesii)凋落叶为研究对象,于2021年4—7月,对照森林地表和持续流水的溪流,研究间歇性溪流凋落叶分解过程中胞外酶活性变化规律。结果表明:(1)间歇性溪流凋落叶分解过程中酸性磷酸酶、β-葡萄糖苷酶、β-N-乙酰氨基葡萄糖苷酶和脲酶活性总体高于地表,低于溪流。(2)通过分析胞外酶化学计量比和矢量特征,发现三种生境凋落叶分解过程中微生物群落受碳和磷的共同限制。分解初期,间歇性溪流凋落叶分解过程中微生物群落相对碳限制程度高于其他两个生境,但相对磷限制低于地表,高于溪流;随着分解的进行,间歇性溪流凋落叶分解过程中微生物群落相对磷限制程度逐渐减弱,相对碳限制程度逐渐加强。(3)统计分析表明,间歇性溪流中大气温度是凋落叶分解过程中胞外酶活性的主控因子,而地表凋落叶分解过程中胞外酶活性与大气温度、地表温度和土壤含水量关系更为密切,溪流凋落叶分解过程中胞外酶活性主要受水体温度、溪流深度和气温等因子的影响。研究结果为全面认识亚热带森林生态系统物质迁移与循环过程提供了新思路和科学依据。The extracellular enzyme activities of Castanopsis carlesii leaf litter were evaluated during the decomposition in intermittent streams,forest floor and streams from April 2021 to July 2021 in this study.The results showed that:(1)the extracellular enzyme activities of acid phosphatase,β-Glucosidase,β-N-acetylglucosaminidase and urease were higher than those in forest floor but lower than those in streams.(2)Ecoenzymatic stoichiometry and enzyme vector features indicated that microorganisms in the three habitats were restricted by carbon and phosphorus availability in the process of leaf litter decomposition.The carbon limitation of the microbial community was higher than that in the stream and forest floor while phosphorus limitation was lower than the forest floor but higher than that in streams in the early stage of decomposition.With the progress of litter decomposition,the degree of phosphorus limitation was weakened but the carbon limitation was strengthened during the process of litter decomposition of leaf litter in subtropical intermittent streams.(3)The statistical analysis showed that air temperature greatly accounted for the variation in extracellular enzyme activities in intermittent streams,while air temperature,soil moisture content and soil temperature were more closely related to extracellular enzyme activities in forest floor.Meanwhile,the extracellular enzyme activity of stream litter was mainly affected by factors such as water temperature,stream depth and air temperature.These results provide new ideas and scientific basis for a comprehensive understanding of the material fluxes and circulation process in subtropical China.

关 键 词：微生物养分限制 胞外酶化学计量比 胞外酶活性 不同生境 

分 类 号：S714[农业科学—林学]