Forests are a critical component of the global carbon cycle because they take carbon dioxide out of the atmosphere through photosynthesis, and store the carbon in wood and soil. All living things in forests also produce carbon dioxide through respiration as an inevitable consequence of sustaining themselves and growing. At present, forests take in more carbon dioxide than they release, helping to reduce the amount of carbon dioxide present in the atmosphere, but this 'free gift' from forests is not guaranteed to continue at its current rate indefinitely under climate change. As well as the carbon cycle, forests are also crucial in the water cycle as trees pump water from the soil into the atmosphere. Leaves are the key part of the plant that regulates the exchange of gases (water, carbon dioxide) with the atmosphere. The pores in the leaf surface (stomata) are important for water loss and temperature control as well as the entry of carbon dioxide. Leaves exposed to direct sunlight can be more than ten degrees hotter than the air, even in temperate latitudes. Leaf temperature is important because many biological processes, including photosynthesis and respiration, are sensitive to temperature; very high temperatures can cause immediate and acute damage to leaves. Over the coming century, we expect carbon dioxide concentrations and air temperatures to continue to rise. When trees are grown in higher carbon dioxide concentrations, stomata close and limit water loss; this prevents the plant dehydrating but also reduces how much leaves can cool down. However, there is limited monitoring on forest canopy temperatures, and limiting understanding on how different species and forests in different climate zones are responding to climate change. This project will build a global network of researchers working to measure forest canopy temperatures using thermal infrared cameras, which will provide both greater understanding and also a crucial data resource for scientists in other disciplines to utilise. The network will ensure that the data collected by separate groups are comparable, and aid data processing and analysis by providing clear guidance and tools. This is will encourage other researchers to take up use of thermal infrared cameras, the analysis of which can be challenging. Our network will monitor canopy temperatures at fourteen sites in tropical and temperate forests and savannah, in UK, China, India, Australia, Brazil, Peru, Panama, USA, and Ghana. The sites in the UK and Peru will be newly established by this project. Ten sites already have established data collection, while the final two sites (Australia, Ghana) are in development. Having data collected using cameras will allow us to understand not only how forests in different locations are behaving, but also whether and how different species within sites respond. The long-term nature of the project means that seasonal variation will be included, and the forest response to extreme events such as heat waves and droughts will be quantified. Future work will establish in more detail how changes to canopy temperature link to changes in forest carbon and water cycling. Our work providing insight into the response of forest canopies to climate change will inform models produced to assess the impacts of greenhouse gas emissions on the planet, which are used to inform global climate change policies. Further, the current global emphasis on mitigating climate change through tree planting makes it crucial to assess how these trees will cope under future conditions.

We propose an international network to explore this key knowledge gap in understanding the effects of pests and pathogens in accelerating tropical rainforest tree mortality during drought. The project will deliver an integrated and focused anlaysis, using expertise in plant physiology, forest ecology and microbial and insect ecology. It will also make use of the unique leverage of the world's only long-term drought experiment network in tropical forests. We will use field-based workshops at two current tropical forest drought experiments, in Australia and Brazil, to bring together experts in plant function, the effects of pest and pathogen ('biotic') attack on woody tissue, and vegetation modelling. New ground-based and remotely-sensed measurements will be examined to test for relationships between measures of biotic attack and metrics of plant function during experimental drought. We will compare responses in different tree size classes, tree species groups, and at the level of the forest ecosystem (large experimental plot treatment). The outcome will be new insights into the causes of tropical rainforest tree death from drought, in relation to plant physiology and insect or microbial attack. This insight will be delivered in the form of new data, new scientfic articles and information that can be used by vegetation modellers to predict the effects of drought on tropical forests in the future. The group of experts built using these funds will form a pre-eminent multi-disciplinary consortium in the subject area, capable of advancing the subject into the future for the benefit of the science, interested environmental policy makers and university educators.

In the lower atmosphere ozone (O3) is an important anthropogenic greenhouse gas and is an air pollutant responsible for several billion euros in lost plant productivity each year. Surface O3 has doubled since 1850 due to chemical emissions from vehicles, industrial processes, and the burning of forests. While land ecosystems (primarily forests) are currently slowing down global warming by storing about a quarter of human-released carbon dioxide (CO2) emissions, this could be undermined by rising O3 concentrations impacting forest growth. This in turn would result in more CO2 left in the atmosphere adding to global climate change. Tropical rainforests are responsible for nearly half of global plant productivity and it is in these tropical regions that we are likely to see the greatest expansion of human populations this century. For example, Manaus, in the centre of the Amazon rainforest has seen a population boom in the last 25 years, with the number of residents doubling to just over 2 million people. Alongside this growing population, we see the expansion of O3 precursor emissions from urbanization and high-intensity agricultural areas. The global impacts of changing air pollution on tropical forests are potentially profound. In his seminal work in 2007, PI Sitch and colleagues at the Met Office and Centre for Ecology and Hydrology, were the first to identify the large potential risk to tropical forests from O3 pollution, and how that could in turn accelerate global warming. However, their study presented two major challenges for the research community: 1) the scale of this effect is highly uncertain; as their global modelling study was based on extrapolating plant O3 sensitivity data from temperate and boreal species. This project will address this by providing the first comprehensive set of measurements of O3 effects on plant functioning and growth in tropical trees. Also, as both O3, CO2 and H2O are exchanged between the atmosphere and leaves through a plants stoma, higher levels of CO2 provide plants the opportunity to reduce their stomatal opening, which in turn leads to reduced O3 uptake and damage. This project will for the first time investigate the potential synergistic or antagonistic impacts of climate change (CO2 and Temperature) on O3 responses in tropical forest species. 2) a fundamental challenge in all global vegetation modelling is to accurately represent the structure and function of highly biodiverse ecosystems; global models are generally only able to represent a limited set of generalized plant functional types (e.g. evergreen trees, C4-grasses etc). However, recent collection and synthesis of plant functional trait data (e.g. leaf nutrient concentrations, leaf size and shape) have enabled improved representation of ecology and plant function in global models. A group of scientists, including project partner Johan Uddling, have very recently proposed a unifying theory for O3 sensitivity in temperate and boreal tree species based upon leaf-functional traits. We are in a unique position to take this work forward to test the theory in tropical forest species, and to test the implications of this at the regional and global scale. The inclusion of the relationship between O3 sensitivity and basic plant functional traits in our global vegetation model, JULES (Joint UK Land Environmental Simulator), will lead to a step-change in our ability to assess the impact of air quality on tropical forest productivity and consequences for carbon sequestration. The model will be applied at O3 hotspot locations in tropical forests and together with observed plant trait information and O3 concentrations we will be able to extrapolate beyond the single plant functional type (PFT) paradigm. Global runs of JULES will also enable us to investigate the implications of future O3 concentrations, changes in land-use, and climate change scenarios on the tropical forest productivity and the global carbon sink.

Convection of the Earth's mantle is a fundamental dynamic process that profoundly influences the surface of our planet, affecting processes as diverse as plate tectonics, long-term sea level change, and climate. Convection requires a balance between material sinking deep into the mantle and rising towards the surface. Whilst we know that downwelling material is dominated by subducting slabs that eventually sink thousands of km into the mantle, the locations, durations, and dynamics of the required deep upwelling material are much more ambiguous. The best-known surface indication of such upwelling is intraplate volcanism (volcanism located far from plate boundaries), classically associated with plumes (or 'hotspots') of hot material rising from the lower mantle. Particularly voluminous examples of intraplate volcanism occur when the broad heads of these plumes reach the surface to produce large igneous provinces (LIPs). These LIPs affect the world's atmosphere via the release of massive amounts of gases like sulphuric acid, changing the climate with damaging effects on the ocean, atmosphere, and biology (i.e., mass extinctions). The trails of hotspot volcanoes that come after the LIP have also proved a powerful tool in discovering the past motions of tectonic plates. For these reasons, understanding the origins and evolution of intraplate volcanism is an important part of Earth science. The classic example of hotspot intraplate volcanism is Hawaii on the Pacific plate: a series of volcanic islands and submerged undersea mountains ('seamounts') that stretches away to the northwest, becoming progressively older the further they are from the actively erupting island of Hawaii. However, intraplate volcanism on Earth is very diverse. Many localities do not fit the classic model of a hot plume rising from the deep mantle, but instead appear to have been caused by processes in the upper mantle or have a mix of deep and shallow characteristics. For this project, the seas off Eastern Australia are an ideal region for studying the processes involved in the formation of intraplate volcanism. This region is crossed by not one, but three sub-parallel chains of intraplate volcanoes, which erupted simultaneously between 35 and 6 million years ago. These volcanoes are up to 5 km high and 100 km across, and are almost entirely submerged beneath the ocean. The long life and exceptional age progression of the chains are strong indicators of a classic deep upwelling source, but the configuration of the three chains challenges our understanding of this fundamental driving force of our planet. Neither three closely spaced plumes (~500 km apart) nor an upwelling sheet fit well with our understanding of the underlying physics: they are either unstable or are not observed in models of Earth's mantle convection. Instead, these observations suggest a deep upwelling splitting as it nears the surface, perhaps due to obstacles in the mantle, or eddies in the mantle convection. This proposal builds on a collaboration with Australia, who has already funded a 28 day voyage (worth ~£1.8 million) to collect rock samples and carry out geophysical studies. The voyage will target the two marine chains, as well as the Louisiade Plateau (a 100,000 square km area of raised seafloor that could be a LIP) north of the Tasmantids. We will study these volcanoes using a multi-faceted approach combining chronology (to determine their ages), chemistry (to determine what type of mantle melted), and geodynamic modelling (to examine the processes in the mantle that formed the volcanoes). The geodynamic models will also be applied to the Canary and Comoros Islands (west and east of Africa, respectively) to examine the mechanisms behind intraplate volcanoes elsewhere on the planet. This project will give us significant insight into the formation of enigmatic intraplate volcanism and how material flowing from deep in the Earth's mantle interacts with obstacles as it rises.

On coastal reefs (0-50 m depth), perhaps more than anywhere in the world, natural and human systems share a history of strong dependence that must be taken into account to maintain, on one side, the long-term human development and well-being, and, on the other side, biodiversity. This biodiversity translates directly into services. Reef fishes support the nutritional and economic needs of people in many poor countries while hosting the major part of marine life on Earth (25%). However world's reefs are severely over-fished or have degraded habitats. Avoiding or escaping this negative spiral and identifying the most vulnerable reef social-ecological systems on Earth are among the major issues that scientists and managers are facing today. The project aims to move beyond the typical over-simplified ‘human impacts’ storyline and focus on uncovering new solutions based on a prospective and integrated modelling approach of reef social-ecological systems at the global scale with three objectives: 1.Quantifying five key services provided by reef fishes: (i) biomass production providing livelihoods, (ii) nutrient cycling that affects productivity, (iii) regulation of the carbon cycle that affects CO2 concentration, (iv) cultural value that sustains well-being tourism activities and (v) nutritional value insuring food security. 2.Determine the conditions (socioeconomic and environmental) under which these ecosystem services are currently maintained or threatened. Based on a global database of fish surveys over more than 5,000 reefs that encompass wide gradients of environments, human influences (fishing impact), and habitats, we will estimate the boundaries or thresholds beyond which these ecosystem services may collapse. 3.Predict the potential futures of these services and social-ecological systems under various global change scenarios. Using multiple integrated scenarios (human demography, economic development and climate change) and predictive models we will simulate the dynamics of shallow reef ecosystems and their ability to deliver services during the next century.