Introduction

The Global Tree Assessment is an initiative to have conservation assessments for all the world’s tree species available on the IUCN Red List of Threatened Species. It began in 2015 in recognition of the need to make more conservation information available for tree species, to make more and better informed decisions regarding their conservation. The production of conservation assessments for trees enables prioritisation of practical conservation action, research and funding to species at greatest risk of extinction in the wild.

The Global Tree Assessment is the largest conservation assessment to ever be undertaken. It is coordinated by BGCI and the IUCN Species Survival Commission Global Tree Specialist Group (IUCN-SSC GTSG) and acts as a continuation and expansion of the red list activities undertaken by the two groups over the last 20 years.

Since 2015, there has been a four-fold increase in the number of assessments for tree species published on the IUCN Red List. Several new red list publications for complete tree groups, and regional tree floras have been produced. Other conservation tools have also been developed through the Global Tree Assessment such as GlobalTreeSearch, ThreatSearch and the GlobalTree Portal.

State of the World’s Trees

In September 2021, BGCI released The State of the World’s Trees report. This was the interim report for the Global Tree Assessment, reporting on the first five years of the programme. The report finds that 30% (17,500) of tree species are currently at risk of extinction. That means there are twice the number of threatened tree species globally than threatened mammals, birds, amphibians and reptiles combined.

The greatest threats facing trees include habitat loss from agriculture and grazing, followed by over exploitation from logging and harvesting. The report finds that 1 in 3 trees currently harvested for timber are threatened with extinction. Climate change and extreme weather are emerging threats to tree species globally. Additionally, it reveals that 1 in 5 tree species are directly used by humans, for food, fuel, timber, medicines, horticulture, and more.

The report is both a catalyst for action and also a call for hope as it found > 3 in 5 tree species are found in at least one protected area worldwide and at least 1 in 5 trees are conserved ex situ in botanic gardens or seed banks.

Who is Involved

We work with other 60 botanical organisations and 25 IUCN Species Survival Commission groups, as well as hundreds of tree experts to produce conservation assessments of trees.

We have established partnerships with government agencies and NGOs across all tree diversity hotspots, to produce conservation assessments for endemic trees in these highly diverse regions. We are supporting taxonomic experts producing assessments for large tree families such as Lauraceae, Lamiaceae and Annonaceae. We are also working with other IUCN Red List specialist groups and plant authorities to increase their output of tree assessments.