模拟气候变化对中亚热带杉木人工林土壤微生物生物量和酶活性的影响.doc

模拟气候变化对中亚热带杉木幼林土壤微生物量和酶活性的影响 高金涛1,2，王恩熙1,2，任卫岭1,21,2，陈岳民1,2*,杨玉盛1,2, 施友文3 1. 福建师范大学地理科学学院, 福州 350007 2. 湿润亚国家重点实验室, 福州350007 3三明市三元区林业局 ( 摘要：以中亚热带杉木（Cunninghamia lanceolata）幼苗为研究对象，设置埋设电缆以加热土壤增温结合模拟氮沉降的实验，研究了土壤理化性质、土壤微生物量及土壤酶活性对模拟增温和氮沉降的短期响应。结果表明：短期的增温和施氮并未使土壤有机碳和总氮发生明显变化；但是增温显著增加了0—10 cm和10—20 cm土层的微生物量碳、酸性磷酸酶和木质素降解酶（多酚氧化酶和过氧化物酶）的活性，而对0—10 cm土层的木质素降解酶影响不显著；施氮显著提高了微生物量碳，增加了微生物量C/P，并减弱了木质素降解酶和纤维素水解酶的活性，造成pH下降，使土壤表现出酸化的现象；与单独的增温和施氮处理对比，增温+施氮的联合处理表现出明显的交互作用，并使微生物量碳、微生物量氮、木质素降解酶和几丁质降解酶显著减少，导致土壤进一步酸化和水分缺失。RDA分析表明，pH和水分是决定0—10 cm土层中土壤酶活性最重要的因子，而在10—20 cm土层则是微生物量对土壤酶活性起主要作用。研究表明，中亚热带杉木人工林土壤微生物量和酶活性对模拟增温和氮沉降反应敏感，但更对增温+施氮的联合处理反应敏感且表现出不同的响应方式。因此，该区域在未来全球变化背景下的温度升高和氮素增加以及气候变化多因素的协同效应值得长期而深入的探讨。 关键词：微生物量；土壤酶活性；增温和氮沉降交互作用；杉木幼林 Effects of simulated climate change on soil microbial biomass and enzyme activities in young Chinese fir (Cunninghamia lanceolata) in subtropical China GAO Jintao1,2, WANG Enxi1,2, REN Weiling1,2, LIU Xiaofei1,2, CHEN Yuehmin1,2, YANG Yusheng1,2 , SHI Youwen3 1 School of Geographical Sciences, Fujian Normal University, Fuzhou 350007, China 2 Cultivation Base of State Key Laboratory of Humid Subtropical Mountain Ecology, Fuzhou 350007, China 3 The forestry bureau of Sanming sanyuan district, Sanming 365000, China Abstract: Global warming and nitrogen deposition have been responsible for several environmental disturbances, and have attracted much attention from researchers, government agencies and international community. Recent studies suggest that the trend of global warming and nitrogen deposition will continue over the next few decades. These changes not only affect the growth of aboveground vegetation, but also change the belowground soil environment, and thus directly or indirectly affect the microbial process. The microbial biomass and soil enzymes play significant roles in terrestrial environments, particularly through the decomposition of soil organic matter, dynamic fluctuation between carbon sink and source, and the transformation of soil nu