Woody plants reduce the sensitivity of soil extracellular enzyme activity to nutrient enrichment in wetlands: A meta-analysis
Woody plants reduce the sensitivity of soil extracellular enzyme activity to nutrient enrichment in wetlands: A meta-analysis
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DOI：
10.1016/j.soilbio.2021.108280
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发表时间：
2021-08
影响因子：
9.7
通讯作者：
Tong Li;C. Peng;Z. Bu;Qiu'an Zhu;Hanxiong Song;Xinyi Guo;Meng Wang
中科院分区：
文献类型：
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作者：
Tong Li;C. Peng;Z. Bu;Qiu'an Zhu;Hanxiong Song;Xinyi Guo;Meng Wang
氮（N）和磷（P）沉积量的增加预计会增加湿地土壤有机碳（C）的分解。土壤细胞外酶活性（EEA）是土壤生物地球化学过程的敏感指标，但它们对湿地氮和/或磷富集的响应需要在全球范围内进行评估。我们利用来自 Web of Science 和中国国家知识基础设施的同行评审论文对湿地中氮和/或磷富集后的土壤 EEA 进行了荟萃分析。对 31 项分析氮和/或磷富集的研究中的 7 种土壤 EEA 和 5 种 0-20 厘米深度的土壤化学性质进行了整理，这些研究来自描述湿地植被组成的研究。土壤 EEA 分为 C-、N- 和 P- 获取功能类别。为了研究植被类型对土壤EEA的影响，我们进一步定义了两类具有不同植被类型的湿地：以苔藓/莎草为主的非木本湿地和以灌木/树木为主的木本湿地。我们发现，以苔藓/莎草为主的湿地中的土壤 EEA 比以灌木/树木为主的湿地中的土壤 EEA 更容易受到养分富集的影响。氮富集增加了两类湿地中碳和磷的获取 EEA。然而，对于磷富集，仅在苔藓/莎草为主的湿地中观察到土壤 EEA 的显着响应：β-1,4-葡萄糖苷酶活性平均增加 76%，但磷酸酶活性下降 78%。当氮和磷同时供应时，两个湿地类别的土壤 EEA 保持不变。木本植物可以克服微生物对养分富集的反应，并减轻养分富集对土壤有机碳储量的负面影响。需要进一步研究考虑植物生理和植被动态对土壤EEA的影响，并将湿地土壤EEA模块集成到基于过程的生物地球化学模型中，以更好地了解湿地生态系统对全球变化的反馈。
Greater deposition of nitrogen (N) and phosphorus (P) is expected to increase decomposition of soil organic carbon (C) in wetlands. Soil extracellular enzyme activities (EEAs) are sensitive indicators of soil biogeochemical processes, but their response to N and/or P enrichment in wetlands needs to be assessed on a global scale. We conducted a meta-analysis with peer-reviewed papers from Web of Science and China National Knowledge Infrastructure on soil EEAs after N and/or P enrichment in wetlands. Seven soil EEAs and five soil chemical properties in the 0-20 cm depth from 31 studies analyzing N and/or P enrichment were collated, from studies that described vegetation composition in wetland. Soil EEAs were classified into C-, N-, and P- acquiring function categories. To examine influence of vegetation types on soil EEAs, we further defined two categories of wetlands with different vegetation types: moss/sedge-dominated non-woody and shrub/tree-dominated woody wetlands. We showed that soil EEAs in moss/sedge-dominated wetlands were more susceptible to nutrient enrichments than those in shrub/tree-dominated wetlands. Nitrogen enrichment increased C- and P-acquiring EEAs in both categories of wetlands. However, for P enrichment, significant responses of soil EEAs were observed in moss/sedge-dominated wetlands only: β-1,4-glucosidase activity increased 76% but phosphatase activity decreased 78%, on average. Soil EEAs in both wetland categories remained unchanged when N and P were supplied together. Woody plants may override microbial response to nutrient enrichment and mitigate the negative effect of nutrient enrichment on soil organic C stock. Further studies are needed to consider the effect of plant physiology and vegetation dynamics on soil EEAs, and integrate wetland soil EEAs modules into process-based biogeochemical model to better understand the feedback of wetland ecosystems with global change.