Un-stable microbiomes - Stability to drought of soil microbiomes shaped by land use and plant species

土壤中居住着无数不同的微生物，包括真菌和细菌。这些复杂的微生物群落负责许多生态系统服务，如有机物分解，养分循环以及碳和养分储存。但这些服务受到气候变化的威胁。目前的气候预测预测严重干旱的频率越来越高，这是众所周知的强烈影响土壤微生物群落及其功能。此外，还有第二个威胁这些社区的因素：土地使用集约化。在过去的世纪里，草原土壤中的微生物受到了日益密集的管理。由于对粮食生产的需求不断增加，草原通过施肥进行了大量的土地集约化利用，牺牲了生物多样性（植物和土壤微生物）及其所支持的生态系统服务。这两大威胁将如何相互作用，影响我们未来的生活仍然知之甚少。在这个项目中，我将回答极端和频繁的干旱如何影响土壤微生物群落的问题，以及不同的植物物种和土地管理如何影响土壤微生物群落。我将重点关注微生物群落的稳定性，换句话说，土壤微生物抵抗干旱的能力没有改变，或者干旱后恢复到原始状态的能力。为此，我将进行一系列受控环境和实验室实验。我将从成对的草地上收集土壤，这些草地经历了不同的长期土地利用强度（广泛的传统管理和集约化管理），我将在上面种植两种广泛分布的草种，这两种草种通常在集约化和广泛管理的草地上都很丰富，并且具有明显相反的生长策略（快速生长与缓慢生长）。干旱、土地利用和植物种类对土壤微生物结构和功能的影响将使用最先进的技术进行评估。该项目的结果不仅将产生对土壤微生物群落应对极端气候的机制的新见解，这是一个重要的研究挑战，而且还将产生与BBSRC的战略研究优先事项“粮食安全和可持续管理”相关的新知识。

Soils are inhabited by a myriad of different microorganisms, including fungi and bacteria. These complex microbial communities are responsible for many ecosystem services such as organic matter decomposition, nutrient cycling, and carbon and nutrient storage. But these services are threatened by climate change. Current climate projections predict an increasing frequency of severe droughts, which are known to strongly affect soil microbial communities and their function. Additionally, there is a second factor that threatens these communities: land use intensification. Soil microbes populating grassland soils have suffered from increasingly intensive management over the last century. Due to the ever-increasing demand for food production, grasslands have been subjected to significant land use intensification through fertilisation, at the expense of biodiversity (both of plants and soil microbes) and the ecosystem services it supports. How these two major threats will interact with one another to impact upon our future lives is still poorly understood.In this project, I will answer the question of how extreme and frequent drought affects the soil microbial communities, and how that is influenced by different plant species and land management. I will focus on the microbial community stability, in other words, the capacity of soil microbes to resist drought without changing or their capacity to recover after drought to the original state. To do that, I will carry out a series of controlled environment and lab experiments. I will collect soils from paired grasslands that have been subjected to different long-term land use intensity (extensive traditional management and intensive management) and I will grow on them two widespread grass species, which are typically abundant in intensively and extensively managed grasslands, and have markedly contrasting growth strategies (fast-growing vs slow-growing). The effects of drought, land use and plant species on soil microbial structure and function will be evaluated using state-of-the-art techniques. The results of this project will not only produce new insights into the mechanisms by which the soil microbial communities answer to climate extremes, which represents an important research challenge, but also it will generate new knowledge that is of relevance to BBSRC's strategic research priority of "food security and sustainable management".