Tall stature and small leaves: ecological strategies that enhance tree growth across the subtropical Brazilian Atlantic Forest

Ecological strategies reflect the mechanisms used for species to sustain a population. Predicting plant growth in ecological communities is crucial, especially with climate change impacting ecosystem functioning. By employing a large dataset for the subtropical Brazilian Atlantic Forest (BAF), we evaluated whether species' relative growth rates (RGR) are explained by their ecological strategies. Principal component analyses summarised the relationships among functional traits (leaf, wood and stature traits) to inform about ecological strategies of 121 tree species. We tested three principal components as predictors of RGR for all species collectively, and canopy and understory species separately. Species exhibiting larger stature with small and structured leaves have faster growth. Tall canopy trees, with small leaves and softer wood grew faster, whereas understory species with taller stature, denser wood, and more structured and nutrient-rich leaves had higher RGR. Therefore, strategies that combine higher stature and smaller leaf area are key determinants of the higher relative grow rates of tree species from subtropical BAF, conferring a greater advantage in converting local resources into stem growth. These findings highlight the importance of understanding the coordination between trait-based ecological strategies and tree growth, which is essential for ecosystem functioning in changing environments.