How soil biodiversity influences ecosystem stability in experimental grasslands

了解在面对变化的环境时决定生态系统功能稳定性的因素是生态学研究的重点。生物多样性，特别是植物多样性，是促进生态系统稳定的一个主要因素，这一点日益得到证实。土壤生物多样性构成了地球上生物多样性的一大部分，受到全球人为变化的威胁。然而，关于土壤生物多样性的丧失是否以及如何影响生态系统稳定性，我们知之甚少。由于在实地研究中很难操纵土壤生物多样性，本研究将使用稀释到灭绝的方法来创建具有现实物种丰富度梯度的土壤群落。在温室试验中，将沿着土壤生物多样性梯度建立草地微宇宙。首先，我将利用一个微观实验来检验土壤生物多样性的丧失是否会通过对植物生物量生产的不利影响和植物多样性的稳定作用来降低生态系统的稳定性，或者通过改变植物群落组成来增加生态系统的稳定性。生态系统阻力是生态系统稳定性的重要组成部分，被定义为生态系统功能在扰动过程中发生变化的程度。其次，我将测试土壤生物多样性的丧失是否会导致生物量生产、凋落物分解、土壤团聚体形成、氮磷淋失和养分供应等多种生态系统功能对气候变暖、干旱和氮沉积的抵抗力和弹性降低。这项研究将更好地理解土壤生物多样性丧失与生态系统稳定性之间的联系，这对于预测人类活动引起的土壤生物多样性变化将如何影响生态系统稳定性至关重要。

Understanding the factors that determine the stability of ecosystem functioning when faced with a changing environment is a focal point in ecological research. It is becoming well established that biodiversity, especially plant diversity, is a major factor contributing to ecosystem stability. Soil biodiversity, which comprises a large part of biodiversity on Earth, is threatened by global anthropogenic changes. However, we know little about whether and how the loss of soil biodiversity influences ecosystem stability. Because it is difficult to manipulate soil biodiversity in a field study, the dilution-to-extinction approach will be used to create soil communities with a realistic gradient of species richness in this study. Grassland microcosms will be established along the soil biodiversity gradient in greenhouse experiments. Firstly, I will use a microcosm experiment to test whether soil biodiversity loss can decrease ecosystem stability through its detrimental effects on plant biomass production and the stabilizing effect of plant diversity, or increase ecosystem stability through shifting plant community composition. Ecosystem resistance, defined as the degree to which ecosystem functioning changes during a perturbation, is one important component of ecosystem stability. Secondly, I will test whether the loss of soil biodiversity can result in decreases in the resistance and resilience of multiple ecosystem functions, such as biomass production, litter decomposition, soil aggregate formation, nitrogen and phosphorus leaching and nutrient provision, to warming, drought and nitrogen deposition. This study will provide a better understanding of the links between soil biodiversity loss and ecosystem stability, which is crucial for predicting how anthropogenically induced changes in soil biodiversity will impact ecosystem stability.