Jia Tong, Wang Yuwen, Chai Baofeng
Shanxi Key Laboratory of Ecological Restoration on Loess Plateau, Institute of Loess Plateau, Shanxi University, Taiyuan, China.
Front Microbiol. 2020 Dec 21;11:565806. doi: 10.3389/fmicb.2020.565806. eCollection 2020.
Litter decomposition is the key link between material circulation and energy flow in ecosystems, resulting from the activity of resident microbes and various enzymes. This study investigated enzyme activity in litter and associated microbial community characteristics to help clarify the internal mechanisms associated with litter decomposition, while also providing researchers a scientific basis for soil remediation in mining areas. Results confirmed that the nutrient content of litter significantly increased as phytoremediation years progressed, while enzyme activities in litter varied over different phytoremediation years. During the litter decomposition process, cellulase predominated in the early phytoremediation stage and catalase predominated in the intermediate phytoremediation stage. Obvious differences were found in bacterial community structure and diversity over progressive phytoremediation years. Predominant bacterial genera mainly included , , , , and . Moreover, and had relatively higher betweenness centrality, and played important roles in bacterial community positive interactions. Additionally, total nitrogen (TN) and total zinc in soil, sucrase and catalase activity in litter were the main environmental factors that affected the structural framework of bacteria in litter. However, TN had the greatest overall effect on the structural framework of bacteria in litter. Results from this study can help our understanding of the role that litter plays in degraded ecosystems. Our results also provide a scientific basis for improving poor quality soil in areas affected by copper tailings while also amending ecological restoration efficiency.
凋落物分解是生态系统中物质循环和能量流动的关键环节，是由常驻微生物和各种酶的活动所导致的。本研究调查了凋落物中的酶活性及相关微生物群落特征，以帮助阐明与凋落物分解相关的内在机制，同时也为矿区土壤修复为研究人员提供科学依据。结果证实，随着植物修复年限的增加，凋落物的养分含量显著增加，而凋落物中的酶活性在不同的植物修复年限有所不同。在凋落物分解过程中，纤维素酶在植物修复早期占主导地位，而过氧化氢酶在植物修复中期占主导地位。在不同的植物修复年限中，细菌群落结构和多样性存在明显差异。主要的细菌属主要包括 、 、 、 和 。此外， 和 具有相对较高的中介中心性，在细菌群落的正向相互作用中发挥重要作用。此外，土壤中的总氮（TN）和总锌、凋落物中的蔗糖酶和过氧化氢酶活性是影响凋落物中细菌结构框架的主要环境因素。然而，TN对凋落物中细菌的结构框架总体影响最大。本研究结果有助于我们理解凋落物在退化生态系统中的作用。我们的结果还为改善受铜尾矿影响地区的劣质土壤提供了科学依据，同时也提高了生态恢复效率。
