A new study shows how climate and light conditions interaction affect the early growth in abarco, a highly valued tropical timber species, offering critical guidance for reforestation and sustainable forest management in the face of climate change.

Abarco – a native South American tree prized for its timber and ecological importance – shows strong early growth and survival but also sensitivity to air humidity and sunlight intensity, according to researchers from the University of Eastern Finland and AGROSAVIA – Colombia.

Although large-scale abarco plantations remain scarce in Colombia, the species ranks among the country’s most commercially traded timber species. To promote the expansion of native tree plantations, the Government of Colombia added abarco to its 2025 list of species eligible for financial incentives under commercial reforestation programmes.

The team studied young abarco trees over six years in permanent plots in full sun and in partial shade. They measured diameter, height, crown development, qualitative attributes and health indicators, linking these patterns with climate variables such as rainfall, temperature, humidity and sunlight intensity.

Their results showed that abarco seedlings grew steadily under both light conditions, with diameter growth particularly enhanced in full sun. Growth was correlated with several key climate factors, especially relative humidity, and light availability – indicating that well-lit environments may support more robust development. Survival remained high overall, and pest and disease symptoms were low and more frequently observed in shaded conditions during the early years of the study.

“We found that abarco has strong early growth potential,” says lead author Dr Alexander Pulgar?n D?az of the University of Eastern Finland. “Understanding how climate and light influence young trees helps forest managers make better decisions about where and how to plant this species as climates continue to change.” This study also supports evidence-based decisions in forest restoration, commercial reforestation and conservation efforts, particularly for tropical regions where knowledge of native species’ ecology remains limited.

The study is the first long-term analysis of permanent plots to quantify early growth, survival and climate sensitivity of abarco from seedling establishment through six years under contrasting light conditions. By combining repeated annual measurements with climate data, it provides unprecedented evidence for a widely harvested yet understudied tropical timber species.

This work was funded by the Corporaci?n Colombiana de Investigaci?n Agropecuaria-AGROSAVIA, the LUMETO Doctoral Programme and the School of Forest Sciences at the University of Eastern Finland.

Research article:
Pulgar?n D?az, J.A., Guerra Hincapi?, J.J., L?pez-Zuleta, S., Gil Restrepo, J.P., 2026. Early growth and climate sensitivity of Cariniana pyriformis in northern South America. Forestry: An International Journal of Forest Research 99(2): cpaf089. https://doi.org/10.1093/forestry/cpaf089