Communities in areas prone to natural hazards often have little information about the human and economic losses that may occur in the event of a disaster, or the information needed to minimize such losses. This project is therefore concerned with advancing scientific understanding of the processes occurring in extremely dynamic hydro-geomorphological (river flood) systems, some of which are continuing to adjust following volcanic eruptions over a range of timescales. Advancing process understanding will enable alerts and warnings to be provided to competent authorities, facilitating effective decision making and communication to local communities. Lahar flows and large-scale injections of sediment into river systems during recent volcanic eruptions in Chile (e.g. Chaiten in 2008 and Calbuco in 2015) have resulted in major economic and social costs through damage to homes, transport infrastructure, power plants, salmon farms and tourist businesses. The associated evacuation of entire towns and rural areas highlights an increasing vulnerability and emphasizes the need for improved risk prediction and mitigation. The project will develop improved systems for predicting (a) the timing and magnitude of hydrological hazards and (b) the longer term impacts of sediment release causing flooding in downstream river channels, and will provide (c) training and a 'tool kit' for local authorities to ensure that the monitoring developments in Chile have longevity beyond the project duration.

Latin American forests cover a very large latitudinal and climate gradient extending from the tropics to Southern hemisphere high latitudes. The continent therefore hosts a large variety of forest types including the Amazon - the world's largest tropical forest - as well as the diverse Atlantic forests concentrated along the coast, temperate forests in Chile and Argentina as well as the cold rainforests of Valdivia and the Nothofagus forests of Patagonia. These forests are global epicentres of biological diversity and include several tropical and extra-tropical biodiversity hotspots. For example, the Amazon rainforest is home to ~10% of terrestrial plant and animal species and store a large fraction of global organic carbon. hotspots. Some of these Latin American forests still cover a large fraction of their original (pre-colombian) extent: the Amazon still covers approximately 5 Million km2, which is 80% of its original area. However, others, such as the Atlantic forest, have nearly disappeared and are now heavily fragmented. Temperate forests have also shrunk, despite efforts to halt further reduction. However, economic development, population rises and the growth in global drivers of environmental change mean that all forests now face strong anthropogenic pressures. Locally stressors generally result from ongoing development, selective logging, the hunting of larger birds and mammals, over-exploitation of key forest resources such as valuable palm fruits, mining, and/or forest conversion for agricultural use. Global environmental drivers stem from the world's warming climate. Yet it is not clear how these local pressures and changing environmental conditions will alter the composition of Latin American forests, and whether there are thresholds between human impacts - such as the lack of dispersers in heavily fragmented forest landscapes or climate conditions exceeding limits of species tolerance - and the community level responses of forest plants. We aim to investigate this, supporting the development of strategies that can preserve the diversity of these forests and their functioning. We achieve this by investigating the relationships between diversity and functioning of these forests; exploring whether there are thresholds in functioning resulting both from pressures of forest use and changing climate; by experimentally testing responses; and by generalizing predictive capability to large scales. ARBOLES aims to achieve these goals by integrating established forest inventory approaches with cutting-edge functional trait, genomics, experimental and remote sensing approaches. Our approach involves combining forest plots with plant traits, which will enable us to characterize state and shifts over time in the face of local human disturbance and changing climate and atmospheric composition. We will focus on traits along the following axes: (i) life-history strategies measuring investment in structure (like wood density, leaf mass per area, maximum height), (ii) investment in productive organs (like leaf nutrients), (iii) investment in reproductive organs, (iv) tolerance to water stress and heat stress. The work is being conducted in collaboration with research groups in Argentina, Brazil, Chile and Peru - and will provide a first cross-continent assessment of how humans are influencing Latin American forests.