Tropical and subtropical Asia's valued tree species under threat
Authors: Gaisberger Hannes , Fremout Tobias , Kettle Chris J. , Vinceti Barbara , Kemalasari Della , Kanchanarak Tania , Thomas Evert , Serra‐Diaz Josep M. , Svenning Jens‐Christian , Slik Ferry , Eiadthong Wichan , Palanisamy Kandasamy , Ravikanth Gudasalamani , Bodos Vilma , Sang Julia , Warrier Rekha R. , Wee Alison K. S. , Elloran Christian , Ramos Lawrence Tolentino , Henry Matieu , Hossain Md. Akhter , Theilade Ida , Laegaard Simon , Bandara K. M. A. , Weerasinghe Dimantha Panduka , Changtragoon Suchitra , Yuskianti Vivi , Wilkie Peter , Nghia Nguyen Hoang , Elliott Stephen , Pakkad Greuk , Tiansawat Pimonrat , Maycock Colin , Bounithiphonh Chaloun , Mohamed Rozi , Nazre M. , Siddiqui Baktiar Nur , Lee Soon‐Leong , Lee Chai‐Ting , Zakaria Nurul Farhanah , Hartvig Ida , Lehmann Lutz , David Dzaeman B. Dzulkifli , Lillesø Jens‐Peter Barnekow , Phourin Chhang , Yongqi Zheng , Ping Huang , Volkaert Hugo A. , Graudal Lars , Hamidi Arief , Thea So , Sreng Sineath , Boshier David , Tolentino Enrique , Ratnam Wickneswari , Aung Mu Mu , Galante Michael , Isa Siti Fatimah Md , Dung Nguyen Quoc , Hoa Tran Thi , Le Tran Chan , Miah Md. Danesh , Zuhry Abdul Lateef Mohd , Alawathugoda Deepani , Azman Amelia , Pushpakumara Gamini , Sumedi Nur , Siregar Iskandar Z. , Nak Hong Kyung , Linsky Jean , Barstow Megan , Koh Lian Pin , Jalonen Riina 
Published: December 2021

Tree diversity in Asia's tropical and subtropical forests is central to nature‐based solutions. Species vulnerability to multiple threats, which affect provision of ecosystem services, is poorly understood. We conducted a region‐wide, spatially explicit assessment of the vulnerability of 63 socioeconomically important tree species to overexploitation, fire, overgrazing, habitat conversion, and climate change. Trees were selected for assessment from national priority lists, and selections were validated by an expert network representing 20 countries. We used Maxent suitability modeling to predict species distribution ranges, freely accessible spatial data sets to map threat exposures, and functional traits to estimate threat sensitivities. Species‐specific vulnerability maps were created as the product of exposure maps and sensitivity estimates. Based on vulnerability to current threats and climate change, we identified priority areas for conservation and restoration. Overall, 74% of the most important areas for conservation of these trees fell outside protected areas, and all species were severely threatened across an average of 47% of their native ranges. The most imminent threats were overexploitation and habitat conversion; populations were severely threatened by these factors in an average of 24% and 16% of their ranges, respectively. Our model predicted limited overall climate change impacts, although some study species were likely to lose over 15% of their habitat by 2050 due to climate change. We pinpointed specific natural areas in Borneo rain forests as hotspots for in situ conservation of forest genetic resources, more than 82% of which fell outside designated protected areas. We also identified degraded areas in Western Ghats, Indochina dry forests, and Sumatran rain forests as hotspots for restoration, where planting or assisted natural regeneration will help conserve these species, and croplands in southern India and Thailand as potentially important agroforestry options. Our results highlight the need for regionally coordinated action for effective conservation and restoration.