Li Yunfei, Wang Bingyao, Wang Zhanjun, He Wenqiang, Wang Yanli, Liu Lichao, Yang Haotian
Key Laboratory of Ecological Safety and Sustainable Development in Arid Lands, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China.
Shapotou Desert Research and Experiment Station, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China.
Microorganisms. 2024 Aug 23;12(9):1752. doi: 10.3390/microorganisms12091752.
Rhizosphere microorganisms play a pivotal role in biogeochemical cycles, particularly in relation to carbon (C) and nitrogen (N) cycles. However, the impact of stand age on the composition of rhizosphere microbial communities and the abundance involved in C and N cycling remains largely unexplored in restoration ecosystems dominated by shrubs of temperate deserts. This study focuses on revealing changes in microbial composition and functional genes in the rhizosphere soil of after revegetation, as well as their response mechanisms to changes in environmental factors. The alpha diversity of bacteria tended to increase with stand age, whereas that of fungi decreased. The abundance of denitrification; dissimilatory nitrate reduction to ammonium, nitrification, and ammonium assimilation; and C fixation-related gene levels increased with stand age, whereas those related to the degradation of starch, pectin, hemicellulose, cellulose, and aromatics decreased. The parameters MBC, MBN, and TC were the key factors affecting the bacterial community, whereas the fungal community was regulated by TN, EC, pH, and MBC. Stand age indirectly regulated C and N cycling functions of genes through altered soil properties and microbial community structures. This study presents a novel approach to accurately evaluate the C and N cycling dynamics within ecosystems at various stages of restoration.
根际微生物在生物地球化学循环中起着关键作用，特别是在碳（C）和氮（N）循环方面。然而，在以温带沙漠灌木为主的恢复生态系统中，林分年龄对根际微生物群落组成以及参与碳氮循环的微生物丰度的影响在很大程度上仍未得到探索。本研究着重揭示植被恢复后根际土壤微生物组成和功能基因的变化，以及它们对环境因子变化的响应机制。细菌的α多样性随林分年龄增加而趋于增加，而真菌的α多样性则降低。反硝化作用、异化硝酸盐还原为铵、硝化作用和铵同化作用以及碳固定相关基因水平随林分年龄增加而升高，而与淀粉、果胶、半纤维素、纤维素和芳烃降解相关的基因水平则降低。微生物量碳（MBC）、微生物量氮（MBN）和总碳（TC）参数是影响细菌群落的关键因素，而真菌群落则受总氮（TN）、电导率（EC）、pH值和微生物量碳（MBC）的调控。林分年龄通过改变土壤性质和微生物群落结构间接调控基因的碳氮循环功能。本研究提出了一种新方法，可准确评估生态系统在不同恢复阶段的碳氮循环动态。
