FAPESP - Restoring Neotropical dry ecosystems - is plant functional composition the key to success?

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Despite their global importance and poor protection, TDFS have been studied far less than other tropical forest ecosystems, particularly TDFS areas undergoing restoration. We aim to address this recently identified knowledge gap with the aim of improving the success of TDFS restoration. This project will provide the first assessment of the resilience of existing and restored TDFS to changing climate and climate extremes, through undertaking a comprehensive, community-scale assessment of traits which determine plant water-use, carbon production and nutrient-use strategies across restored TDFS sites. The information generated in this project will create a step-change in our current understanding of the function of restored and natural TDFS sites, facilitating development of state-of-the art vegetation models to improve climate prediction and the creation of new restoration policy through integrating with key stakeholders responsible for the creation and implementation of restoration strategies for Brazil. Our key aims are:Aim 1: Evaluate ecosystem function in TDFS sites restored using different strategies.Aim 2: Understand the pressures on TDFS from climate-change and climate extremes.Aim 3: Improve policy and restoration strategies for the restoration of, and long-term resilience of TDFS in collaboration with the Brazilian government.Tropical dry forests and savannas (TDFS) make up 34% of Brazil's land area and contain >50% of Brazil's plant species. More than 100 million people live in TDFS regions of Brazil and many of these people are from rural vulnerable communities who rely on essential ecosystem services TDFS provide. These services include: 1. water supply, shade and pollinators for Brazil's agricultural frontier; 2. national water security, with 43% of the surface water outside the Amazon falling in TDFS and supplying the aquifers which feed Brazil's three largest river basins; 3. a source of timber and food; 4. carbon storage for climate change mitigation; 5. areas of natural beauty, used extensively for tourism; 6. a living seed bank for >4500 woody plant species, many of which are endemic. Despite this, TDFS remain poorly protected with only 1.2% of dry forests and 7.5% of savannas in protected reserves and <10% of Brazil's dry forest and <20% of its savannahs remaining intact. Recognising the social, economic and environmental implications of the current rates of loss of TDFS, the Brazilian government has responded by committing to restoring 120,000 km2 (an area about half the UK) of natural ecosystems by 2030, with a focus on TDFS. Brazil's Ministry for the Environment (ICMBio) and Ministry for Agriculture (EMBRAPA) have started implementing this restoration plan. However, success rates of restored TDFS areas remains very low, with high variability between areas subjected to varying restoration strategies. The reasons for low success and high variability between strategies remains unknown, hampering current ability to meet national restoration targets. Until now, all TDFS restoration strategies have focused on re-creating the species composition observed in natural, undisturbed TDFS habitats. This focus has assumed that species diversity is synonymous with maximizing ecosystem productivity and resistance to climate variability, yet it ignores the suitability of these species to the new drier and disturbed environment they experience in degraded landscapes. The latest research from tropical rainforests broadly suggests that focusing only on species' diversity is too narrow. Instead, plant resource use strategies, and particularly hydraulic functional traits are likely to be the key to determining ecosystem-scale function and the resistance and resilience of TDFS ecosystems to current and future climate variability. To successfully protect and restore TDFS it is therefore vital that the current lack of understanding about ecosystem function and plant resource-use strategies in TDFS is addressed.