In a new report published today, the State of the World’s Trees shows that 30% of all tree species – more than 17,500 species – are threatened with extinction. That is more than double the total number of globally threatened mammals, birds, reptiles and amphibians.
Individual tree species play numerous economic, ecological and cultural roles, and contribute to healthy, resilient ecosystems, which are so vital in addressing the huge challenges that our world faces today. The grim status of the world’s tree species demonstrates the urgent need to scale up efforts to conserve these cornerstone species, for the benefit of people, ecosystems and the wider world.
The report, which represents the first conservation assessment of all of the world’s trees, has been produced by the Global Tree Assessment (GTA), an initiative led by BGCI and the IUCN Species Survival Commission (SSC) Global Tree Specialist Group (GTSG). The report brings together expertise from over 60 institutional partners and over 500 individuals who have contributed to assessing the risk to tree species over the past five years.
The report also identifies the greatest threats to tree species. Habitat loss, especially for conversion to agriculture, threatens more tree species than any other known factor. Direct exploitation of trees, especially for timber, is the second most common threat, and invasive (and other problematic) species ranks third. We already know that climate change impacts forest ecosystems, but the State of the World’s Trees shows us that it is emerging as a significant threat to individual tree species too. For many trees, the threat does not come from just one source – a combination of multiple threats often interacts to exacerbate the detrimental effects on the species’ survival.
For example, the Mulanje cedar, Widdringtonia whytei, found naturally only on Mount Mulanje, is threatened by overexploitation, but fires and invasive species also contribute to the species’ decline and it is listed as Critically Endangered on the IUCN Red List.
The report finds that at least two-thirds of all tree species are living within at least one protected area and nearly one-third are found in botanic gardens, seed banks or other ex situ collections. Further action is required, however, as these measures do not necessarily guarantee the species’ survival.
The State of the World’s Trees can also be used to identify countries with high numbers of threatened trees. Brazil holds both the highest number of tree species at 8,847, and also the most threatened tree species, at 1,788. It is islands, however, that are more proportionally at risk, due to their high levels of endemism and uniqueness.
Hope for the future
The hope is that now, armed with the data from the Global Tree Assessment and BGCI’s new GlobalTree Portal, an online database designed to track conservation efforts for trees at a species, country, and global level, new action for threatened trees will be prioritised.
The State of the World’s Trees outlines five key recommendations for policymakers and experts in order to conserve threatened trees, including expanding protected area networks, extending ex situ conservation, growing funding, increasing tree planting schemes and improving global collaboration. Importantly, these actions need to be targeted to threatened tree species.
Paul Smith, Secretary General, BGCI said: “This report is a wake up call to everyone around the world that trees need help. Every tree species matters — to the millions of other species that depend on trees, and to people all over the world. For the first time, thanks to the information provided by the State of the World’s Trees report we can pinpoint exactly which tree species need our help, so policymakers and conservation experts can deploy the resources and expertise needed to prevent future extinctions.”
From information to action
Over the coming weeks, GTC will be sharing more information on how we can grow the global taskforce of policymakers, conservation organisations, tree planters, funders and others working together to conserve threatened trees globally.
Read State of the World’s Trees here.