Tropical and subtropical Asia's valued tree species under threat

Tree diversity in Asia's tropical and subtropical forests is central to nature-based solutions. Species vulnerability to multiple threats, which affects the provision of ecosystem services, is poorly understood. We conducted a region-wide, spatially explicit vulnerability assessment (including overexploitation, fire, overgrazing, habitat conversion, and climate change) of 63 socio-economically important tree species selected from national priority lists and validated by an expert network representing 20 countries. Overall, 74% of the most important areas for conservation of these trees fall outside of protected areas, with species severely threatened across 47% of their native ranges. The most imminent threats are overexploitation and habitat conversion, with populations being severely threatened in an average of 24% and 16% of their distribution areas. Optimistically, our results predict relatively limited overall climate change impacts, however, some of the study species are likely to lose more than 15% of their habitat by 2050 because of climate change. We pinpoint specific natural forest areas in Malaysia and Indonesia (Borneo) as hotspots for on-site conservation of forest genetic resources, more than 82% of which do not currently fall within designated protected areas. We also identify degraded lands in Indonesia (Sumatra) as priorities for restoration where planting or assisted natural regeneration will help maintain these species into the future, while croplands in Southern India are highlighted as potentially important agroforestry options. Our study highlights the need for regionally coordinated action for effective conservation and restoration

Range-wide priority setting for the conservation and restoration of Asian rosewood species accounting for multiple threats and ecogeographic diversity

Understanding the impact of multiple anthropogenic threats on tree species is urgently needed for estimating population decline and enabling coordinated and efficient conservation actions. We applied a spatially explicit framework to assess the vulnerability of three highly valuable Asian rosewood species (Dalbergia cochinchinensis, D. cultrata, D. oliveri) to five key threats across their native ranges in six countries of the Greater Mekong Subregion. All three species face significant threat levels from at least one of the five threats in more than 75% of their native ranges, including within existing protected areas. Overexploitation is the single most important threat (53–60%), followed by habitat conversion (17–41%) and fire (20–28%). About 21% of the distribution range of D. cultrata is under medium to very high threat from climate change, which is predicted to have less impact on D. oliveri and on D. cochinchinensis. Based on our threat assessment we delineated species-specific priority areas for conservation and restoration that we subdivided by ecoregions as a surrogate for adaptive variation within species. Half of the ecoregions were classified as priority for improving the conservation of adaptive variation in one or more of the species. We propose spatially explicit follow-up actions that include in situ conservation, restoration, and ex situ conservation to improve the effectiveness of current conservation measures to capture adaptive variation within species. Transboundary coordination will be important to effectively address conservation threats. The study can act as a model for regional planning for other valuable tree species

Occurrence data for native Asian tree species gathered during the APFORGIS project

This dataset has occurrence data of 63 tree species gathered during the APFORGIS project “Establishing an Information System for conserving native tree species and their genetic resources in Asia-Pacific”. It includes information from 24 countries and covers the period since 1952 to 2019