氮沉降对中亚热带米槠天然林微生物生物量及酶活性的影响

发布时间：2018-06-26 09:12

本文选题：氮沉降 + 微生物生物量　；参考：《生态学报》2017年01期

【摘要】：氮沉降对土壤微生物的扰动可能会影响土壤的养分循环,然而关于中亚热带天然林土壤微生物及酶活性对氮沉降的响应鲜有报道。通过3 a的氮沉降模拟实验,研究中亚热带米槠天然林土壤的理化性质、土壤微生物量及土壤酶活性的响应。结果表明:氮沉降并未引起土壤的有机碳和总氮显著性变化;高氮(80 kg N hm~(-2)a~(-1))处理下,土壤p H下降,出现酸化现象;低氮(40 kg N hm~(-2)a~(-1))处理促进淋溶层(A层)中土壤纤维素分解酶(β-葡萄糖苷酶和纤维素水解酶)和木质素分解酶(多酚氧化酶和过氧化物酶)活性升高,同时促进土壤微生物生物量碳、氮的积累。冗余分析(RDA)表示,可溶性有机碳(DOC)是驱动A层土壤酶活性的重要环境因子;而在淀积层(B层),这4种酶活性并未发生显著性差异。施氮处理后,A、B层中土壤的酸性磷酸酶活性增加(P0.05)。研究表明:低水平氮沉降增加了土壤微生物生物量碳氮含量以及土壤有机碳分解相关酶活性,从而加速了土壤碳周转;这为未来氮沉降增长背景下,探索中亚热带天然林土壤碳源汇问题提供了依据。
[Abstract]:The disturbance of nitrogen deposition on soil microorganisms may affect the nutrient cycling of soil. However, there are few reports on the response of soil microbial and enzyme activities to nitrogen deposition in natural forests in the middle subtropics. The physical and chemical properties, soil microbial biomass and soil enzyme activity of Castanopsis carlesii natural forest in the middle subtropics were studied by simulating nitrogen deposition for 3 years. The results showed that nitrogen deposition did not cause significant changes in soil organic carbon and total nitrogen, and soil pH decreased and acidified under high nitrogen (80 kg N hm ~ (-2) a ~ (-1) treatment. Low nitrogen (40 kg N hm ~ (-2) a ~ (-1) increased the activities of soil cellulolytic enzymes (尾 -glucosidase and cellulose hydrolase) and ligninolytic enzymes (polyphenol oxidase and peroxidase) in the leaching layer (layer A). At the same time, promote the accumulation of soil microbial biomass carbon and nitrogen. Redundancy analysis (RDA) showed that soluble organic carbon (DOC) was an important environmental factor driving soil enzyme activity in layer A, but there was no significant difference among the four enzymes in the deposition layer (layer B). The activity of acid phosphatase increased after nitrogen application (P0.05). The results show that low level nitrogen deposition increases soil microbial biomass carbon and soil organic carbon decomposition related enzyme activity, thus accelerates soil carbon turnover. The study of soil carbon source and sink in the middle subtropical natural forest provides the basis.
【作者单位】：福建师范大学地理科学学院;福建师范大学湿润亚热带山地生态国家重点实验室培育基地;
【基金】：国家自然科学基金重点资助项目(31130013) 国家“973”计划资助项目(2014CB954003)
【分类号】：S714

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