Print PageThere is currently debate on the fate of tropical forests in the face of predicted climate change. Tropical trees are believed to be vulnerable to increase in both day and night-time temperatures, with the potential for both species loss and changes in net productivity. However, little direct evidence exists of the effect of elevated temperature upon biomass accumulation in tropical tree species. We used controlled-environment chambers at the Smithsonian Tropical Research Institute, Panama to monitor growth, photosynthesis, and morphological features in seedlings of six tropical lowland species.
Results/Conclusions
All species tested showed a positive growth response to increasing temperature. Surprisingly, plants exposed to the highest temperature regime (39°C day/31°C night) exhibited the highest biomass accumulation. This temperature is markedly above the long-term averages of maximum and minimum temperatures (32 and 22°C respectively) seen across much of lowland Panama. In addition, species showed a range of morphological and physiological responses to increased temperature, including altered biomass allocation (i.e. root-shoot ratio), stem elongation, changes in leaf morphological traits, and photosynthetic capacity. Therefore we conclude that tropical tree species may have a greater thermal niche than previously thought. Although, we note our study is restricted to single life history stage and misses the importance of short-term aberrations in temperature, which may have a substantial role in dictating species ultimate survival.
