Soil Extracellular Enzymatic Stoichiometry along a Hydrologic Gradient of Hillslope Riparian Zone of the Three Gorges Reservoir

作者：Hongyun Qu, Guomei Jia, Xiao Liu, Hanyu Xiang, Yunfei Yue, Hailing Zhang · 发表于：Soil Science Society of America Journal · 年份：2019 · DOI：10.2136/sssaj2018.12.0509 · 被引用次数：3 · 研究领域：Soil erosion and sediment transport、Groundwater and Watershed Analysis、Plant responses to water stress

Core Ideas A higher BG/NAG and a lower NAG/AP were seen in LI compared with the NI site. BG/AP and BG/NAG in SI were lower compared with the NI site. Soil BG/AP was significantly negatively related to the soil C/P and N/P ratios. The hydrological gradient was a key influencing factor of enzymatic stoichiometry. Phosphorus was the main limiting element for microbial processes in the riparian zone. The riparian zone of reverse seasonal flooding caused by dam operation has become a nutrient availability and biogeochemical “hot spot.” However, the limitations of soil nutrient availability on soil microbial growth in these ecosystems are poorly understood. Four subsites with different inundation durations (longer‐term inundation [LI] at 145–155 m asl, middle inundation [MI] at 155–165 m asl, shorter‐term inundation [SI] at 165–175 m asl, and no inundation [NI] at 175–185 m asl used as a control) associated with an elevation gradient were chosen to estimate the extent of potential microbial nutrient limitations through soil extracellular enzymatic stoichiometry. The results showed that, although soil β‐1,4‐glucosidase (BG), β‐14‐N‐acetyl‐glucosaminidase (NAG), and acid (alkaline) phosphatase (AP) were lower in the riparian zone than the NI sites, a higher BG/NAG and a lower NAG/AP in LI and lower BG/AP and BG/NAG ratios in SI were found compared with the NI sites, indicating a greater C and P limitation on microbial processes in LI and a stronger N and P limitation on microbial pro...