Li Niu, Li Jingrou, Nie Ming, Wu Ming, Wu Jihua
Ministry of Education Key Laboratory for Biodiversity Science and Ecological Engineering, Coastal Ecosystems Research Station of Yangtze River Estuary, School of Life Sciences, Institute of Biodiversity Science and Institute of Eco-Chongming, Fudan University, Shanghai, China.
Wetland Ecosystem Research Station of Hangzhou Bay, Research Institute of Subtropical Forestry, Chinese Academy of Forestry, Hangzhou, Zhejiang, China.
Front Microbiol. 2023 Jul 26;14:1233352. doi: 10.3389/fmicb.2023.1233352. eCollection 2023.
Grazing prohibition is an effective management practice to restore salt marsh functioning. However, the effects of grazing exclusion on denitrifying microbial communities and their controlling factors in salt marshes remain unclear.
In this study, we surveyed soil physicochemical properties and above- and below-ground biomass and using quantitative polymerase chain reaction and Illumina MiSeq high-throughput sequencing technology to determine the relative abundance, composition, and diversity of nitrite reductase - and -type denitrifying bacterial communities associated with grazing prohibition treatments and elevations.
The abundance of -type denitrifiers increased with grazing prohibition time, whereas the abundance of -type denitrifiers remained unaltered. Moreover, -type denitrifiers were more abundant and diverse than -type denitrifiers in all treatments. Grazing prohibition significantly altered the operational taxonomic unit richness, abundance-based coverage estimator, and Chao1 indices of the -type denitrifying bacterial communities, whereas it only minimally affected the structure of the -type denitrifying bacterial community.
The results imply that the community, rather than , should be the first candidate for use as an indicator in the process of salt marsh restoration after grazing prohibition. Substances of concern, total nitrogen, and salinity were the key environmental factors affecting the abundance and community composition of and denitrifiers. The findings of this study provide novel insights into the influence of the length of grazing prohibition and elevation on - and -type denitrifying bacterial community composition in salt marshes.
禁牧是恢复盐沼功能的有效管理措施。然而，禁牧对盐沼中反硝化微生物群落的影响及其控制因素仍不清楚。
在本研究中，我们调查了土壤理化性质以及地上和地下生物量，并使用定量聚合酶链反应和Illumina MiSeq高通量测序技术来确定与禁牧处理和海拔相关的亚硝酸还原酶型和型反硝化细菌群落的相对丰度、组成和多样性。
型反硝化菌的丰度随禁牧时间增加，而型反硝化菌的丰度保持不变。此外，在所有处理中，型反硝化菌比型反硝化菌更丰富、更多样。禁牧显著改变了型反硝化细菌群落的操作分类单元丰富度、基于丰度的覆盖率估计值和Chao1指数，而对型反硝化细菌群落的结构影响最小。
结果表明，在禁牧后的盐沼恢复过程中，群落而非群落应作为首选指标。关注物质、总氮和盐度是影响型和型反硝化菌丰度和群落组成的关键环境因素。本研究结果为禁牧时间长度和海拔对盐沼中型和型反硝化细菌群落组成的影响提供了新的见解。
