Substrate quality overrides soil salinity in mediating microbial respiration in coastal wetlands

作者：Qiang Li, Zhaoliang Song, Shaopan Xia, Laodong Guo, Bhupinder Pal Singh, Yu Shi, Weiqi Wang, Yu Luo, Yongchun Li, Junhui Chen, Jianchao Zhang, Shaobo Sun, Hailong Wang · 发表于：Land Degradation and Development · 年份：2023 · DOI：10.1002/ldr.4792 · 被引用次数：14 · 研究领域：Coastal wetland ecosystem dynamics、Microbial Community Ecology and Physiology、Peatlands and Wetlands Ecology

Abstract As productive and essential ecosystems, coastal wetlands have experienced increased environmental impacts such as saltwater intrusion and eutrophication, resulting in significant shifts in microbially mediated ecosystem functions, such as carbon sequestration and nutrient transformations. The soil microbial respiration, a primary process in the transfer of carbon from soil to the atmosphere, is susceptible to environmental changes. However, studies on how salinity affects soil microbial respiration in coastal wetlands have not been fully explored. Soil samples were systematically collected from divergent sampling sites covering medium‐ and extremely‐saline wetlands along a river‐estuary‐coast continuum to investigate mechanisms controlling soil microbial respiration in coastal wetlands. According to the results, the microbial biomass and carbon‐related extracellular enzyme activities were significantly lower in extremely saline (ECe >15 ds m −1 , ES) than medium and highly saline soils (ECe <15 ds m −1 , MHS) ( p < 0.05), indicating a suppressive effect of salinity on soil microbiota. Meanwhile, high‐salinity soils had lower vector length and soil microbial respiration rates, suggesting that soils with low carbon limitation might cause less carbon loss under higher salinity environments. Moreover, it was showed that increased available phosphorus could alleviate microbial carbon limitations. Changes in the microbial functional community demonstrated that the...