Disentangling mechanisms of co-adaptation between trees and soil food webs in response to environmental perturbations

树木与生活在其下土壤中的数千种微小动物和微生物相互作用。他们间接或直接地做到了这一点。间接相互作用是通过产生枯枝落叶，特别是枯叶而发生的。当凋落物产生时，土壤动物和微生物将其分解并循环利用营养物质，而进行这一分解过程的群落组成可能受到凋落物本身的性质的影响，例如它含有多少氮或它有多坚韧。直接的相互作用是因为一些微生物与树根密切相关，实际上与树木形成了互利的关系。这些生物依靠树木以糖的形式提供能量，它们的活动为许多对树木健康和营养至关重要的过程提供燃料。生态学中的一个大问题是，这些相互作用将如何受到全球气候变化因素（如干旱和大气中二氧化碳浓度升高）的影响？我们的项目将解决这个问题。另一个问题是，全球变化的组成部分是否会以不同的方式影响这些间接和直接的相互作用，我们的建议也将解决这个问题。我们将通过在实验室中进行实验来解决这些问题，在实验室中我们可以控制各种重要因素，但也会使用两个惊人的实地实验。这些实验人为地控制了成熟橡树林中二氧化碳的浓度、干旱的频率和严重程度，这些橡树比大多数房屋都高。实验规模很大，我们很幸运能从基础设施和支持方面的数百万英镑投资中获益。实验室实验将使用最先进的稳定同位素示踪实验，这使我们能够追踪碳原子从植物到土壤再到土壤生物的命运。我们的发现将对植物相互作用和塑造土壤中自己的生物环境的方式以及气候变化如何改变这种方式产生新的机制见解。了解这些相互作用很重要，因为在管理土地获取食物、燃料、纤维和其他生态系统服务时，我们经常有意或无意地断开共同适应的食物网。利用这些新知识为橡树林地的创建、保护和管理战略提供信息，将增强更广泛的社会影响（见影响之路）。

Trees interact with thousands of tiny animals and microorganisms living in soil beneath them. They do this indirectly and directly. Indirect interactions occur via production of dead litter, especially leaves. When litter is produced, soil animals and microorganisms break it down and recycle nutrients, and the composition of the community doing this breakdown process can be influenced by the nature of the litter itself, such as how much nitrogen it contains or how tough it is. Direct interactions occur because some microorganisms are intimately associated with tree roots and actually form mutually beneficial associations with trees. These organisms rely on trees for their energy in the form of sugars, and their activity fuels many processes essential for tree health and nutrition. A big question in ecology is how these interactions will be affected by components of global climate change, such as drought and elevated concentrations of carbon dioxide in the atmosphere? Our project will tackle this question. A further question concerns whether components of global change will affect these indirect and direct interactions in different ways, and our proposal will also address this issue.We will tackle these issues by undertaking experiments in the laboratory where we have lots of control of various important factors, but also by using two amazing field-based experiments. These experiments artificially manipulate concentrations of carbon dioxide and the incidence of drought frequency and severity in mature oak forests, where the trees are taller than most houses. The experiments are big, and we are fortunate to have the benefit of multi-million pound investment in infrastructure and support. The laboratory experiments will use state-of-the-art stable isotope tracer experiments, which enable us to trace the fate of carbon atoms from plants to soil to soil organisms. Our findings will generate new mechanistic insight into the way that plants interact and shape their own biotic environment in soil, and how this is modified by climate change. Understanding these interactions is important because in managing land for food, fuel, fibre, and other ecosystem services, we routinely disconnect co-adapted food webs deliberately or inadvertently. Broader societal impact will be enhanced by using this new knowledge to inform strategies for creating, conserving and managing oak woodland (see Pathways to Impact).