# The Tervuren xylarium Wood Density Database (TWDD)

## TL;DR

The Tervuren xylarium Wood Density Database (TWDD) fills a major gap by providing extensive wood density data from diverse global regions, especially Africa.

## Contribution

TWDD introduces a large, globally distributed wood density dataset with significant African representation and many new species.

## Key findings

- TWDD includes 13,332 samples from 2,994 species across six continents, with 72% from Africa.
- The database adds 1,164 new species, 160 new genera, and 8 new plant families not previously in major wood density datasets.
- It offers multiple wood density measurements, including oven-dry, air-dry, green, and basic density for most samples.

## Abstract

Wood density is a key plant property, indispensable for estimating forest biomass. Yet, despite tropical regions’ substantial contributions to global tree diversity and carbon cycling, they remain underrepresented in wood density datasets such as the CIRAD and Global Wood Density Database (GWDD). To address this gap, we present the ‘Tervuren xylarium Wood Density Database’ (TWDD), containing 13,332 samples from 2,994 species, 1,022 genera, and 156 plant families across six continents (72% from Africa). TWDD offers direct measurements of oven-dry (oven-dry mass/oven-dry volume, all samples), air-dry (air-dry mass/air-dry volume, 6,408 samples), green (green mass/green volume, 1,657 samples), and basic wood density (oven-dry mass/green volume, 1,686 samples). Basic density was estimated for the remaining 11,646 samples via conversion from oven-dry density. TWDD closes a substantial wood density data gap, especially in Africa, adding 1,164 new species, 160 new genera, and 8 new plant families not included in GWDD or CIRAD datasets. The TWDD provides a critical resource for advancing research on forest community dynamics, ecosystem functioning, carbon cycling, and trait-based ecology worldwide.