Assessing the extinction risk to timber species

Conservation Problem

The global timber market is growing, putting unprecedented pressure on timber species and threatening them with extinction from overexploitation yet little is known about the threat to each species.

Project Goal

To assess the conservation status of all of the world’s timber species and identify the species most at risk of extinction from over-exploitation.

Why these species?

Timber trees are an important source of income in many countries due to the high value raised through exportation and within the manufacturing industry. Timber trade contributes some $468 billion to the global economy every year. Timber species are often major components of forests, providing food and habitat to many species and protecting natural systems such as maintaining water resources. Some species are also culturally significant.

Despite their importance, documentation, knowledge and species specific information for timbers is lacking. At present many commercially used timber species lack an up-to-date conservation assessment.

The threat faced by timber species is growing due to the increasing demand for timber and timber products. Timber trees are uncommon in cultivation due to their size and the need for long, often decades, rotation periods. This means wild populations are under pressure and are threatened by harvest exhaustion due to this rising demand for wood.

Stems of Pterocarpus erinaceus a threatened rosewood timber species from western Africa. Credit; Xander van der Burght and RBG, Kew

Forests where the species are found can be poorly managed and harvest unsustainable, an issue exacerbated by the illegal harvest of timber. Poor harvest regimes reduces the regeneration potential of long-lived species and negatively impacts current and future population sizes. Timber trees are further threatened by forest clearance for agriculture space and infrastructure development, in particular roads.

The risk faced by each individual timber species is still not known and therefore conservationists are unable to identify where targeted action is need to protect these valuable trees from overexploitation. Up-to-date information on these species is urgently needed to ensure the protection of these species from extinction.

What are we doing about it?

In a Toyota funded project, alongside IUCN, GTC will produce 1,500 IUCN red list assessments for priority timber trees. Each year 250 new timber species will be assessed and the project will focus on different timber groups or regions over the course of 5 years. As part of this project we will;

  •  Prioritising 250 timber trees for assessment each year, using the Working List of Commercial Timber Tree species
  • Producing 1,500 assessments for timber species. Some timber species will be re-assessed to better reflect the current risk they face, while other timbers will get their first conservation assessment. Each year the project will focus on different timber groups or regions to assess.
  • Conversing with timber trade and regional and taxonomic experts to review and add to assessments to ensure they are reflective of the threat faced by the species across its range.

Gonystylus bancanus Critically Endangered timber from Southeast Asia. Credit; Ismalil Parlan and FRIM

Key achievements

Since the start of the project, GTC have produced over 500 red list assessments for timber trees and many, many more are in the process of being written, reviewed and published. In the first year of the project, assessments were generated for European timbers, Acers and Dipterocarpaceae. Work on the latter two groups continues alongside other timber families. As a priority GTC, are also producing assessments for timber species protected under the Convention for the Illegal Trade of Endangered Species (CITES). Already assessments for CITES Guaiacum species have been published and assessments for Guibourtia and Pterocarpus species are underway.

Contact details

For more information on this project, please contact


Mark, J., Newton, A.C., Oldfield, S. and Rivers, M. 2014. The international timber trade: a working list of commercial timber tree species. Botanic Gardens Conservation International, Richmond-

Did you know?

Trees from the Dipterocarp family are the dominant species in Southeast Asia’s rainforests. In some cases, they comprise up to 90% of the canopy layer.