CORESCAM: Studying Coastal Biodiversity Resilience to Increasing Extreme Events in Central America.

A project co-led by Rosa Román Cuesta (CIFOR), Ana Rey and Miguel Bastos Araújo (both from MNCN-CSIC).

Synthesis: Central America (Mesoamerica+Caribbean) has been dubbed the miner’s canary of climate change due to the marked increase in extreme events and their impacts over humans and ecosystems. Nowhere in the world collide so many climate and geo hazards over a world’s hotspot of biodiversity and endemism (and migration), within a background of increasing human pressures and increasing long-term drought. If targeting early warning lessons from changes in extreme events and biodiversity resilience, Central America is the place. And these new ab-normals are here to stay. Thus, global warming has increased the impacts of hurricane seasons by altering four key risk factors in their development and translation: higher atmospheric moisture (more rainfall and flooding), lower translational speed (higher residence times), higher ocean-supplied-energy (more intense winds), and higher sea-levels (higher in-land reach and coastal flooding). Because all these risk factors relate to increasing temperatures, their associated climate hazards can only increase in the future. Whilst our ability to track extreme events is increasing, their effects on biodiversity are not yet fully understood, nor properly monitored. This partly relates to the lack of long-term monitoring programs -and funding- to track ecological responses along time. Thus, many of the available studies of biodiversity responses to extreme events focus on species responses less than one year after the disturbance and do not follow species nor ecosystem recovery over time. This constrains our understanding of how resilient species and ecosystems are to changing patterns of extreme events. As an example, in the case of hurricanes and birds, Wunderle’s research in Puerto Rico points out that the greatest stress of a hurricane to terrestrial bird populations occurs after its passage rather than during its impact. The most vulnerable terrestrial wildlife populations after hurricanes have a diet of nectar, fruit, or seeds; nest, roost, or forage on large old trees; require a closed forest canopy; have special microclimate requirements and/or live in a habitat in which vegetation has a slow recovery rate. Small populations with these traits are at greatest risk to hurricane-induced extinction, particularly if they exist in small isolated habitat fragments. This is the case of many Caribbean islands and endemic habitats in the Mesoamerican and Caribbean Biological Corridors. Another example relates to the case of corals and extreme droughts. Prior to 2015, the most extreme El Niño events observed to impact coral reefs globally occurred in 1982–83 and 1997–98. The 2015–2016 El Niño surpassed these events both in terms of ocean warming intensity and extent, causing the highest cumulative stress on corals globally on record . For the Mesoamerican region, the Monitoring Program of the Healthy Reef Initiative showed that 21% of corals bleached in 2015/16, although no long-term mortality was noted. However, the recent and intense the El Nino 2017-2018 heat has worryingly brought the Mesoamerican Reef to bleaching 18 levels above 2015-2016 whose long-term consequences are not yet known. As the return time between bleaching events decreases, coral resistance to extreme events will reduce, making coral resistance strategies (e.g shift of coral species towards heat resistant) more important than recovery. As suggested by these two studies, to properly understand the resilience of biodiversity to extreme events, we need long-term monitoring and regional scales that can help foster regional survival and conservation. This proposal covers these two points by relying on long-term databases for both marine and terrestrial ecosystems that have undergone several extreme events. We also offer regional coverage to promote regional conservation planning. Our proposal will offer conservation insights to managers, conservationists and policy makers, on key lessons learnt about the challenges and opportunities for efficient and effective coastal conservation planning in an era of intensified climate extremes.