Impacts of climate-driven evolution on plant-soil interactions and ecosystem functioning

在全球范围内，我们依靠草原来支持生物多样性，确保农业生产力，提供休闲区，并提供广泛的其他有价值的生态系统服务；例如，英国乳制品行业依赖于草原，每年价值约42.7亿英镑。与此同时，草原是变化最大、保护最少的生物群落之一，不可避免地会受到气候变化迫在眉睫的影响：变暖、干旱、洪水。草原内的生物可能最终通过适应来应对气候变化；要么通过进化，即环境变化选择那些基因编码有利特征的个体，要么通过生理或生长模式的可逆（“可塑性”）变化。只有进化才能带来持久的适应性变化。因此，进化具有缓冲种群免受气候变化不利影响的潜力。然而，进化变化对生态系统内共存物种和重要生态系统功能（如养分循环）的更广泛影响仍未得到解决。例如，“草原”可能看起来只是由植物组成，但在表面之下有一个繁荣的微生物群落（细菌和真菌），它们与植物相互作用，影响植被的多样性和生产力，植物营养，甚至进化。由于它们的繁殖速度快，数量多，这些微生物在气候变化等压力下迅速进化。因此，为了理解气候对草原的影响，整合地上和地下发生的进化和生态过程的影响至关重要。我们的研究将通过将气候驱动的进化变化置于适当的生态环境中来解决这些紧迫的问题。二十多年来，我们将英国巴克斯顿附近的天然草地暴露在模拟气候变化（变暖、降雨增加和干旱）中。我们发表的和初步的研究表明，模拟的气候变化已经改变了植物和微生物群落，并推动了植物内部的进化变化。在这些先前的发现的基础上，我们的总体目标是利用巴克斯顿气候变化实验来确定在气候变化期间，地上和地下群落如何共同进化，如何相互作用，从而塑造生态系统过程。在此过程中，我们的目标是了解草原提供的服务的变化，并提供预测和管理这些变化的方法。我们设计了一套有凝聚力的实验来检查从基因到生态系统反应等层面的关键问题，使用实验室微观环境、生长室实验和现场操作。在三年的时间里，我们将：i)从野外现场检查两种生态上重要的微生物物种，以确定长期气候变化处理如何推动进化；Ii)利用包括微生物和植物在内的微观环境来了解微生物适应如何影响植物适应性和生态系统功能；Iii)确定植物的进化变化如何反过来改变土壤中的微生物种类。我们将使用广泛的技术来实现这些目标，从基因组测序，以确定土壤微生物进化变化的遗传基础，到呼吸测量，以了解进化如何改变生态系统“呼吸”的方式。我们的研究将为植物和土壤生物如何共同应对气候变化以及由此导致的生态系统水平过程的变化提供独特的，进化的观点。

Globally, we depend on grasslands to support biodiversity, ensure agricultural productivity, offer recreational areas, and provide a wide range of other valuable ecosystem services; e.g. the UK dairy industry depends on grasslands and is worth ~£4.27 billion per annum. At the same time, grasslands are among the most altered and least protected biomes, and will inevitably be subjected to the imminent effects of climate changes: warming, drought, flooding.Organisms within grasslands may ultimately cope with climate change by adapting; either through evolution, where environmental change selects for individuals whose genes encode advantageous characteristics, or by reversible ("plastic") changes in physiology or growth pattern. Only evolution leads to lasting adaptive change. Thus, evolution has the potential to buffer populations against the adverse effects of climate change. However, the wider effects of evolutionary change, on coexisting species within ecosystems, and on important ecosystem functions, such as nutrient cycling, remain unresolved. "Grasslands", for instance, may seem to be composed of just plants, but beneath the surface there is a thriving microbial community (bacteria and fungi) that interacts with plants to influence the diversity and productivity of the vegetation, plant nutrition, and even evolution. With their rapid generation times and massive populations, these microbes evolve rapidly under pressures such as climate change. Consequently, to understand climate-driven impacts in grasslands, it is essential to integrate the effects of evolutionary and ecological processes that occur both above-, and belowground.Our research will address these pressing issues, by placing climate-driven evolutionary change in an appropriate ecological context. For over two decades, we have exposed a natural UK grassland near Buxton to simulated climate change (warming, increased rainfall, and drought). Our published and preliminary research shows that simulated climate change has already altered plant and microbial communities and has driven evolutionary change within plants. Building on these previous findings, our overarching goal is to use the Buxton climate change experiment to determine how above- and belowground communities co-evolve, and interact with each other during climate change, to shape ecosystem processes. In doing so, we aim to understand changes in the services that grasslands provide, and offer the means to predict and manage these changes. We have designed a cohesive set of experiments to examine key issues at levels ranging from genes to ecosystem responses, using laboratory microcosms, growth-chamber experiments, and field manipulations. Over three years, we will: i) examine two ecologically important microbe species from the field site to determine how long-term climate change treatments drive evolution; ii) use microcosms that include microbes and plants to understand how microbial adaptation affects plant fitness and ecosystem function; iii) determine how evolutionary change in plants, in turn, alters microbial species in the soil. We will use a wide range of techniques to reach these goals, from genome sequencing, to identify the genetic basis of evolutionary change in soil microbes, to respiration measurements, to understand how evolution changes the way ecosystems "breathe". Our research will provide a unique, evolutionary view of how plants and soil organisms respond together to climate change, and of resulting shifts in ecosystem-level processes.