Multiple mechanisms associated with loss of seed bank diversity under nitrogen enrichment

作者：Miaojun Ma, Anu Eskelinen, Yun‐Peng Zhao, Carol C. Baskin, Chunming Xin, Panhong Zhang, Zengpeng Guo, Hui Zhang, Xuejing Wang, Pengfei Zhang, Guozhen Du · 发表于：Journal of Ecology · 年份：2025 · DOI：10.1111/1365-2745.14486 · 被引用次数：11 · 研究领域：Legume Nitrogen Fixing Symbiosis、Soil Carbon and Nitrogen Dynamics、Plant nutrient uptake and metabolism

Abstract The soil seed bank is a hidden community below‐ground and a crucial component of plant biodiversity. Nitrogen (N) enrichment can reduce plant species diversity both in above‐ground plant communities and seed banks. However, the mechanisms by which N enrichment affects soil seed banks are not clear. We investigated the direct and indirect mechanisms of N enrichment in soil seed banks in an N addition experiment in an alpine meadow on the eastern Tibetan Plateau. We combined above‐ground plant community and litter data, fungal diversity, seed bank surveys and seed rain monitoring, and conducted a seed burial experiment to explore seed viability. We found that the rate of loss of species diversity was slower in seed banks than in above‐ground plant communities. N enrichment directly affected seed banks by decreasing seed viability and enhancing seed germination. Furthermore, small seeds were more prone to loss of viability and increased seed germination under N enrichment than large seeds. At the same time, N enrichment also indirectly decreased seed bank species richness and number of seeds by altering the composition of the plant community and by increasing the amount of litter and fungal diversity. N enrichment also indirectly decreased number of seeds in seed banks through decreasing number of seeds of seed rain, with increasing negative effects due to higher levels of N enrichment. Synthesis . Our results provide novel insights into multiple direct and indirect mec...