Abstract:
We study population and functional changes in a large forest plot (25-ha) located in eastern Ecuador. Previous studies suggest that climate change affect species in different ways. For instance, secondary species may become more important in Amazonian forests. And the forest itself is supposed to experience frequent and intense droughts. If these is true, species less tolerant to drought are expected to become more common in more humid habitats, such as the humid valleys and will become less common in less humid areas, such as the hill tops and slopes. In this study we test these predictions. The plot was stablished in 1995. Since then, four censuses has been made. We present results of 12 years (divided in two intervals). We use functional traits such us maximum size, wood density, seed mass and specific leaf area to address these questions. We found that the forest is decreasing in wood density, maximum size and specific leaf area in the second time interval. In the two time intervals, the population of 5 and 6% of the species increased or decreased significantly (>6 times of the original population). Contrary to the expectations, species increased tenfold in (dry) ridges than in (wet) valleys by the second interval. Only two species, one in ridge and another in valley, increased systematically in both time intervals and no species decreased in both censuses. Our results suggest that the secondary species are becoming more important, but not that species are increasing in population in the humid valleys.