Climate change vulnerability assessment for habitats in Tram Chim National park, Vietnam

With the intention to support ecosystem-based adaptation and future conservation programs in Tram Chim national park, this study applied a question-based tool for habitat climate change vulnerability at a protected area scale. As a representative of the Lower Mekong River Delta ecosystem, the Tram Chim national park is greatly influenced by the Vietnam South climate and Mekong river regime. There are 3 habitats in Tram Chim national park with different water depths, flood duration, and elevations: swamp, inundated seasonal grassland, and melaleuca woodland. Under the current climate, the baseline vulnerability assessment highlights the ecosystem degradation with adverse impacts from human impacts and divergence in fire and water management practices. Under the RCP4.5 and RCP8.5 scenarios, there are 4 climate change stressors that could affect this protected area: temperature increase by almost 2°C, precipitation variation change associated with flood and drought, hydrological change, and change in extreme weather events. Seemingly, the temperature rise is a Serious issue, drought risk is a Serious to a Very serious issue, flood risk is a Moderate issue, hydrological change and extreme weather events change are Moderate to Serious issues to habitats. Together with upstream development, these climatic issues force all habitats exposure to 4 climatic-hydrology changes: hydrology and hydraulics variation, flood extent, depth and duration change, change in turbidity (change in removed sediment from the watershed), and extreme weather events alternation. About the sensitivity, all the habitats in this site have Broad to Intermediate tolerances to heat, turbidity, and soil erosion, while having Broad to Very broad flood tolerance. With narrow drought tolerance and narrow tolerance to extreme weather events (king tide, salt intrusion, and storms), the inundated seasonal grasslands and swamp tends to be more sensitive. The adaptive capacity of habitats in Tram Chim national park is Low, due to the fact that it is constrained by the high possibility of invasive species intensification, lack of integrity, connectivity, and the existence of many physical barriers and limited available areas for habitat expansion and movement. The melaleuca woodland has a higher potential to be the new habitat for other species in Tram Chim national park as the result of climate change impacts. The study reveals that the habitat vulnerability in Tram Chim national park is enhanced as the consequences of the synergy of dam construction and climate change on the Lower Mekong River Delta ecosystem.