College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, 210095, China.
Centre for Grassland Microbiome, State Key Laboratory of Herbage Improvement and Grassland Agro‑Ecosystems, College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou, 730020, China.
Nat Commun. 2024 Apr 3;15(1):2858. doi: 10.1038/s41467-024-47323-3.
Nutrient enrichment is a major global change component that often disrupts the relationship between aboveground biodiversity and ecosystem functions by promoting species dominance, altering trophic interactions, and reducing ecosystem stability. Emerging evidence indicates that nutrient enrichment also reduces soil biodiversity and weakens the relationship between belowground biodiversity and ecosystem functions, but the underlying mechanisms remain largely unclear. Here, we explore the effects of nutrient enrichment on soil properties, soil biodiversity, and multiple ecosystem functions through a 13-year field experiment. We show that soil acidification induced by nutrient enrichment, rather than changes in mineral nutrient and carbon (C) availability, is the primary factor negatively affecting the relationship between soil diversity and ecosystem multifunctionality. Nitrogen and phosphorus additions significantly reduce soil pH, diversity of bacteria, fungi and nematodes, as well as an array of ecosystem functions related to C and nutrient cycling. Effects of nutrient enrichment on microbial diversity also have negative consequences at higher trophic levels on the diversity of microbivorous nematodes. These results indicate that nutrient-induced acidification can cascade up its impacts along the soil food webs and influence ecosystem functioning, providing novel insight into the mechanisms through which nutrient enrichment influences soil community and ecosystem properties.
养分富集是全球变化的一个主要组成部分，它通过促进物种优势、改变营养相互作用和降低生态系统稳定性，经常扰乱地上生物多样性和生态系统功能之间的关系。新出现的证据表明，养分富集还会降低土壤生物多样性，并削弱地下生物多样性与生态系统功能之间的关系，但潜在的机制在很大程度上仍不清楚。在这里，我们通过一项为期 13 年的野外实验，探讨了养分富集对土壤性质、土壤生物多样性和多种生态系统功能的影响。我们表明，养分富集引起的土壤酸化，而不是矿质养分和碳（C）可利用性的变化，是负影响土壤多样性与生态系统多功能性之间关系的主要因素。氮和磷的添加显著降低了土壤 pH 值、细菌、真菌和线虫的多样性，以及与 C 和养分循环有关的一系列生态系统功能。养分富集对微生物多样性的影响也会对微食线虫的多样性产生负面影响，这是更高营养级的影响。这些结果表明，养分诱导的酸化可以沿着土壤食物网级联放大其影响，并影响生态系统功能，为养分富集影响土壤群落和生态系统特性的机制提供了新的见解。
