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

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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.