Páramos are high mountain grassland-peatland biomes (3000m-4000m) that cover a total area of circa 35700km2. They are crucial for the livelihoods and wellbeing of millions of people living in Colombia and neighbouring Northern Andean countries (Venezuela, Venezuela, Ecuador and Peru). Páramos are the main source of water in these regions, are used for crop cultivation and grazing and contain a unique source of untapped genetic diversity. While the Páramos have the potential to support, through the exploitation of its biodiversity, local and regional development, the combined pressure of land use and climate change has already degraded many Páramo areas and their potential demise is a cause for concern for many, including local communities, regional and national policy and decision makers and researchers in Colombia. All agree that any future exploitation requires a sustainable approach and that the management of these systems should enhance the Páramo's resilience to climate change. However, there is still very much which is not known about the functioning of the Páramos and without this knowledge there is a risk that interventions which are designed to achieve sustainability and enhance resilience are not effective or worse detrimental. Páramos are described as sponges that capture and store water from the atmosphere. Few quantitative studies have investigated the mechanisms behind this process and even less is known about the relative role of the plants and the soil of this complex system. Also, Páramos are socio-ecological systems that have been shaped by the human populations that have inhabited them over several centuries. This interaction is continuing to date with local communities relying solely on the Páramo for their livelihoods. This interdisciplinary 3 year project aims to, jointly with Colombian collaborators, establish how the diversity of habitats and of plants within the Páramos contributes to water regulation, via direct storage in live and dead vegetation and via the supply of organic matter in the soil. We will carry out a large field and drone campaign in the Colombian Páramo Guantiva-la Rusia to collect and analyse data on plants, soil and hydrology. We will carry out satellite image analysis to map landscape scale land cover and peatland condition and improve models so that they better represent the hydrology of the ecosystem. The project will also identify how local Páramo inhabitants, particularly crop and livestock farmers, interact currently with the Páramo ecosystem through their day-to-day farming practices. We will invite local people to participate in workshops and storytelling to jointly discover how they understand they are affecting and are affected by the Páramos' water regulation. We will, as we learn more about the functioning of the Páramo, feedback our findings to the local people and so help them initiate more sustainable solutions.

Páramos are high mountain grassland-peatland biomes (3000m-4000m) that cover a total area of circa 35700km2. They are crucial for the livelihoods and wellbeing of millions of people living in Colombia and neighbouring Northern Andean countries (Venezuela, Venezuela, Ecuador and Peru). Páramos are the main source of water in these regions, are used for crop cultivation and grazing and contain a unique source of untapped genetic diversity. While the Páramos have the potential to support, through the exploitation of its biodiversity, local and regional development, the combined pressure of land use and climate change has already degraded many Páramo areas and their potential demise is a cause for concern for many, including local communities, regional and national policy and decision makers and researchers in Colombia. All agree that any future exploitation requires a sustainable approach and that the management of these systems should enhance the Páramo's resilience to climate change. However, there is still very much which is not known about the functioning of the Páramos and without this knowledge there is a risk that interventions which are designed to achieve sustainability and enhance resilience are not effective or worse detrimental. Páramos are described as sponges that capture and store water from the atmosphere. Few quantitative studies have investigated the mechanisms behind this process and even less is known about the relative role of the plants and the soil of this complex system. Also, Páramos are socio-ecological systems that have been shaped by the human populations that have inhabited them over several centuries. This interaction is continuing to date with local communities relying solely on the Páramo for their livelihoods. This interdisciplinary 3 year project aims to, jointly with Colombian collaborators, establish how the diversity of habitats and of plants within the Páramos contributes to water regulation, via direct storage in live and dead vegetation and via the supply of organic matter in the soil. We will carry out a large field and drone campaign in the Colombian Páramo Guantiva-la Rusia to collect and analyse data on plants, soil and hydrology. We will carry out satellite image analysis to map landscape scale land cover and peatland condition and improve models so that they better represent the hydrology of the ecosystem. The project will also identify how local Páramo inhabitants, particularly crop and livestock farmers, interact currently with the Páramo ecosystem through their day-to-day farming practices. We will invite local people to participate in workshops and storytelling to jointly discover how they understand they are affecting and are affected by the Páramos' water regulation. We will, as we learn more about the functioning of the Páramo, feedback our findings to the local people and so help them initiate more sustainable solutions.

Tropical forests are biodiversity hotspots and important biological conservation regions. They deliver key ecosystem services such as carbon sequestration and storage, and water for electricity generation via hydropower (a large source of electricity in many tropical countries) and freshwater provision, serving the needs of millions of people and fast-growing populations in these regions. However, tropical regions have experienced the largest recent increases in heat extremes over the globe, with ongoing warming predicted to exceed the bounds of historic climate variability in the next two decades. This climate change has potentially large but poorly understood consequences for tropical forests. Recent findings suggest that these critical forests appear at substantial risk, in terms of their vulnerability and exposure to warming and its extremes. For example, extreme temperatures in lowland forest reduces tree growth and carbon storage. Furthermore, in the tropical Andes, recent warming has been associated with increased mortality of species in the warm extreme of their thermal ranges, triggering a compositional change towards warm-adapted species across all elevations. The mechanisms underpinning reduced tree growth and species compositional changes remain largely unknown. To predict species composition changes and their implications for forest function and ecosystem services, a mechanistically-informed understanding of the physiological strategies employed by thermally resilient and susceptible species is needed. At our unique warming experiments along elevation gradients in the tropics in the Colombian Andes and in Rwanda in the Albertine Ridge we obtain a range of responses to the warming treatment: some species have died, some have shown reduced growth, while others have increased their growth. Importantly, and contrary to some expectations, plant physiological responses to average site temperatures cannot predict growth patterns. Rather, preliminary evidence suggests that tree growth and survival in the North Andean region and in our experiments in Colombia and Rwanda, is related to species abilities to deal with heat stress. Multiple mechanisms may be involved in determining the ability of species to cope with heat stress, but their relative roles in different settings is unknown. In Rwanda, preliminary data suggest that the most successful species thermoregulate, cooling their leaves via high rates of evapotranspiration to cope with extreme temperature, while species that have shown reduced growth with warming reach very high leaf temperatures (ie they cannot thermoregulate). In contrast, in Colombia, the most successful species are those that emit isoprene to ameliorate heat stress suggesting enhanced thermotolerance may be a key mechanism. Overall, our results demonstrate an urgent need to understand how different tropical tree species cope with extreme rather than average temperatures. Using our experiments in Colombia and Rwanda, this project will deliver new mechanistic understanding of heat stress physiology for tropical forests and possible links to plant growth responses to warming which will inform how we understand and predict composition changes along elevation and climate gradients. We will use a holistic combination of measurements not done before in any ecosystem- thermoregulation, thermal tolerance thresholds, in situ isoprene emissions, and their thermal plasticity- to evaluate tree heat stress strategies. We will combine our experimental data with mechanistic modelling to generalise our results to other ecosystems and with data from Andean trees to determine the extent to which the new understanding of species-level heat stress strategies can explain compositional changes in Andean forest tree species. Our project will support better prediction of future biodiversity shifts and forest function, tropical forest restoration and conservation.

Mangrove forests are often associated with the smell of rotten eggs and swarms of mosquitos. This may be true but at the same time these forests are unique and extremely valuable. Mangrove trees grow in challenging environments surviving hot, muddy and salty conditions as they thrive at the margin of land and sea in the tropics and subtropics. Mangrove ecosystems provide essential habitats for many animal species, they help filtering pollutants and protect the coast against erosion. Moreover, mangroves play a crucial role in combating climate change as they capture and store large amounts of carbon from the atmosphere. In fact, these forests store carbon faster than most land ecosystems. The trees store carbon not only in their wood and leaves, but also in those smelly muddy soils. Despite all these benefits, mangroves are heavily threatened as sea level rise may cause forest drowning and people are increasingly modifying coastal landscapes and interfering with the natural processes on which mangroves depend. The impacts of such pressures on mangrove forests are still unclear, but the consequences may be drastic mangrove loss and reductions in carbon storage. Mangrove trees flourish under very specific conditions. They grow well under regular inundation by tides, but they cannot survive prolonged flooding. Hence mangroves will need to keep raising the bed on which they grow to cope with rising sea levels. Mangroves may accomplish by trapping sediments from the land and the sea with their roots. In addition, dead roots, leaves and branches accumulate within the muddy soils. This helps mangroves to gain elevation and the build-up of dead plant material creates carbon-rich sediments. Now, essentially two possibilities emerge. If mangroves keep up with sea level rise by accumulating carbon-rich plant material in their soils, then carbon stocks can actually increase. However, if sea level rise outpaces mangrove soil buildup, then tree mortality will reduce carbon storage. Limits to the adaptability of mangrove forests to sea level rise exist and these limits are influenced by human activities. Building of river dams, for example, reduces the delivery of sediment to the coast, while this sediment is needed to help raising mangroves and enable continued carbon storage. Clearly, mangrove environments are highly complex and in order to protect these valuable environments, improved understanding and abilities to predict their future are urgently needed. In this project, we will unravel the processes that control how and how much carbon is stored in mangrove forests and develop new computer models to investigate the impacts of sea level rise and human activities on future carbon accumulation. We have selected three sites in Colombia (South America) where mangrove trees reach up to 40 meters (!) making these forests true carbon storage hotspots. First, we will obtain soil samples up to a depth of 2 meters. We will estimate their carbon content, how fast that carbon has accumulated during the past, and where the carbon is coming from. We will also use microscopic plant remains preserved in the soil to discover what mangrove species have grown there in the past and whether this has influenced carbon accumulation. Third, we will develop a model capable of simulating how entire deltas and estuaries with mangrove vegetation evolve over tens to hundreds of years. Finally, we will use this new model to investigate the fate of mangrove forests under rising sea levels and varying sediment supply, and impacts on future carbon accumulation. Colombian high-school students and teachers from will participate in fieldwork and will present their work in science fairs for the general public to increase the awareness of the values of mangrove forests. We will also work together with our project partners to use our findings to support the development of sustainable management strategies in order to safeguard mangrove environments.