Towards a Mechanistic Understanding of Legume Functioning in Natural Restoration of Degraded Ecosystem: Legume‐Specific Impacts on Nitrogen Transformation Processes

作者：Lijun Liu, Qilin Zhu, Yunxing Wan, Ruoyan Yang, Lin Yang, Lei Meng, Mianhai Zheng, Xingliang Xu, Tongbin Zhu, Ahmed S. Elrys, Christoph Müller, Peter Dörsch · 发表于：Plant Cell & Environment · 年份：2025 · DOI：10.1111/pce.15550 · 被引用次数：8 · 研究领域：Soil Carbon and Nitrogen Dynamics、Legume Nitrogen Fixing Symbiosis、Plant nutrient uptake and metabolism

ABSTRACT Legumes have important functions in degraded ecosystems as they can mediate atmospheric nitrogen (N) inputs and increase soil N availability. However, it remains unclear whether legumes affect N availability only through biological N fixation or stimulating microbial N transformations. In this study, nine native legumes and four non‐legumes were collected following a 9‐year natural vegetation restoration experiment in a karst rocky desertification area. Leaf N/phosphorus (P) ratios and various soil N pool compositions were analyzed and gross N transformation rates were determined by 15 N tracing techniques. Legumes exhibited higher leaf δ 15 N values and increased contents of total N, microbial biomass N and inorganic N compared to non‒legumes. Legume leaf N content and N/P ratio (26.7 g kg ‒1 and 20.7) significantly exceeded those of non‒legumes (14.2 g kg ‒1 and 14.5). Our results indicate that legumes increased soil N availability and decreased plant N limitation after 9 years of natural vegetation succession, with effects varying between species and related to soil N transformation processes. Species with low plant N limitation exhibited high rates of organic N mineralization ( M Norg ) and ammonium oxidation to nitrate ( O NH4 ), both of which increase inorganic N supply (especially nitrate). This effect was more pronounced in rhizosphere than bulk soil. M Norg and O NH4 rates were positively correlated ( p < 0.01) with soil organic carbon, total N, water hol...