Unique mapping of canopy diversity in tropical forests
Tropical forest canopies play a crucial role in the biosphere’s carbon, water, and energy cycles. Despite this, they are often treated as uniform in climate system models. A new study now reveals that canopy traits vary significantly across different regions, which could have major implications for how we understand and model forest functions in a changing climate.
By combining field data from over 1,800 vegetation plots with satellite imagery and tree trait data, researchers have mapped the functional diversity of tropical forests. The results show distinct differences between forests in the Americas, Africa, and Asia: American forests exhibit the highest variation, while African forests are more specialized.“Our findings provide a much more detailed picture of how canopy traits vary geographically. This not only helps us better understand the functional diversity of forests but also improves models predicting how different forests will respond to climate change,” says Göran Wallin, researcher at the Department of Biological and Environmental Sciences, and co-author of the study.
The researchers describe two key strategies for forest adaptation. One is high functional richness, meaning a wide range of traits is present. The other is high functional divergence, where certain extreme traits become more prominent, leading to greater specialization.
“When a forest is more specialized, competition for resources is reduced, whereas a high diversity of traits makes adaptation to environmental changes easier. Both strategies are crucial for forests to withstand climate change, but in different ways,” Wallin explains.
To conduct the study, researchers analyzed canopy traits such as leaf nutrient content, size, and thickness from thousands of trees across more than 1,800 plots worldwide. Each tree has an exact coordinate, allowing identification via satellites. Using Sentinel-2 satellite data, they examined how canopies reflect light at different wavelengths. By linking these measurements to soil and climate data, they can now describe tree traits across the entire tropics.
In an upcoming project, the researchers aim to take their analysis further by linking canopy traits to soil biological diversity, where fungi and bacteria play a central role.
The work is led by Dr Jesús Aguirre Gutiérrez at the Environmental Change Institute, University of Oxford, where Göran Wallin is associated.
Read the full article in Nature here: Canopy functional trait variation across Earth’s tropical forests
Aguirre-Gutiérrez, J., Rifai, S.W., Deng, X. et al. Canopy functional trait variation across Earth’s tropical forests. Nature (2025). https://doi.org/10.1038/s41586-025-08663-2
