Evolutionary resistance: Does adaptation stabilise plant community structure and function under climate change?

在全球范围内，我们依靠草原来支持生物多样性和农业生产力，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，每年价值约42.7亿英镑的英国乳制品业完全依赖于草原。与此同时，草原是变化最大、保护最少的生态系统之一，它们现在正受到气候变化的迫在眉睫的影响：变暖、干旱、洪水。草原生物可能最终通过进化适应气候变化，其中环境变化选择具有有利特征（特定“表型”）的物种个体。这种适应性反应既源于表型的变化，也源于生物体在新环境中表达其特征的方式的变化（称为“表型可塑性”）。这两个方面都增加了生物在新环境中茁壮成长的可能性。进化的这两个组成部分都可以缓冲种群免受气候变化的不利影响。然而，我们不知道进化变化将如何改变共存物种的群落或重要的生态系统过程，这些过程支撑着草原对我们社会的重要利益。本研究的重点是物种丰富的草地，它们具有很高的保护价值，是英国景观的标志性特征。它们每平方米可以容纳40多种植物，这些共存的物种中的任何一种都可能在暴露于气候变化时进化。没有人知道组成物种的这些适应性变化如何影响草原植物群落和整个生态系统，以及它们是否会使草原在气候变化期间保持相对不变（“抵抗”）。这是因为，到目前为止，大多数科学家研究的是单个孤立物种的气候驱动进化，这使我们无法评估适应如何影响共存物种之间的相互作用。我们的研究将通过研究气候驱动的自然草原植物群落的进化变化来解决这个问题。二十多年来，我们将英国巴克斯顿附近一个物种丰富的草原暴露在模拟气候变化（变暖、降雨增加和干旱）的环境中。我们的研究表明，在不同的气候处理下，草地植物物种的多样性和丰度变化很小，这意味着植物群落对变化具有抵抗力。然而，我们也证明了一些植物物种正在适应气候处理，这提出了进化本身是抵抗气候变化的来源的可能性，并可以解释这片物种丰富的草原上植物群落的稳定性。在我们之前工作的基础上，我们的总体目标是利用巴克斯顿气候实验作为模型，了解进化变化如何使草地植物在群落和生态系统层面上抵抗气候变化。在这样做的过程中，我们的目标是确定物种多样性如何促进草原提供的服务，并更好地理解（和预测）气候变化对草原的威胁。我们设计了一套实验来研究单个植物对气候变化的进化适应如何影响植物群落的稳定性和重要的生态系统过程。在三年的时间里，我们将测量i) 16种共存植物物种的进化强度和方向，ii)使用数学模型预测气候对草原的影响，iii)在巴克斯顿使用有针对性的实验来测试这些影响。这将涉及构建模型生态系统，并测量物种反应，植物表型和气候处理中的生态系统过程。我们的研究将为气候变化期间植物及其表型如何促进草原和生态系统过程的稳定性提供独特的进化观点。

Globally, we depend on grasslands to support biodiversity and agricultural productivity, offer recreational areas, and provide a wide range of other valuable ecosystem services. For example, the UK dairy industry, which is worth ~£4.27 billion per year, depends entirely on grasslands. At the same time, grasslands are among the most altered and least protected ecosystems, and they are now being to the imminent effects of climate change: warming, drought, flooding.Grassland organisms may ultimately cope with climate change by adapting, via evolution, where environmental change selects for individuals of a species that have advantageous characteristics (specific 'phenotypes'). This adaptive response stems from both changes in phenotype, and changes in the way organisms express their characteristics in a new environment (called 'phenotypic plasticity). Both aspects increase the likelihood that organisms will thrive in the new environment. Both of these components of evolution can buffer populations against the adverse effects of climate change. However, we do not know how evolutionary change will alter communities of coexisting species or the important ecosystem processes that underpin the important benefits of grasslands to our society. This study focuses on species-rich grasslands, which have a high conservation value, and are an iconic feature of UK landscapes. They can contain more than 40 plant species per square metre and any of these coexisting species may evolve when exposed to climate change. Nobody knows how these adaptive changes in component species could influence grassland plant communities and the ecosystem as a whole, and whether they will allow grasslands to remain relatively unchanged ("resistant") during climate change. This is because, to date, most scientists have studied climate-driven evolution in single isolated species, which does not allow us to assess how adaptation could influence interactions among co-existing species. Our research will address this by studying climate-driven evolutionary change in plant communities in a natural grassland. For over two decades, we have exposed a species-rich grassland near Buxton, UK, to simulated climate change (warming, increased rainfall, and drought). Our research has shown very little change in the diversity and abundance of grassland plant species subjected to different climate treatments, meaning that the plant community is resistant to change. However, we have also shown that some of the plant species are adapting to the climate treatments, raising the possibility that evolution itself is the source of resistance to climate change and could explain the stability of the plant community in this species-rich grassland. Building on our previous work, our overarching goal is to use the Buxton climate experiment as a model to understand how evolutionary changes allow grassland plants to resist climate change at the community and ecosystem levels. In doing so, we aim to determine how species diversity contributes to the services that grasslands provide, and to better understand (and predict) threats to grasslands under climate change. We have designed a set of experiments to examine how evolutionary adaptation to climate changes in individual plants influences the stability of plant communities and important ecosystem processes. Over three years, we will measure i) the strength and direction of evolution in 16 coexisting plant species, ii) use mathematical modelling to predict climate impacts on grasslands and iii) test for these impacts using targeted experiments at Buxton. This will involve constructing model ecosystems, and measuring species responses, plant phenotypes, and ecosystem processes in the climate treatments. Our research will provide a unique, evolutionary view of how plants, and their phenotypes, contribute to the stability of grasslands and ecosystem processes during climate change.