Tree Diversity Explains Variation in Ecosystem Function in a Neotropical Forest in Panama

Many experimental studies show that a decline in species number has a negative effect on ecosystem function, however less is known about this pattern in natural communities. We examined the relative importance of environment, space, and diversity on ecosystem function, specifically tree carbon storage in four plant types (understory/canopy; trees/palms), in a tropical forest in central Panama. The objectives of this study were to detect the relationship between tree diversity and carbon storage given the environmental and spatial variation that occur in natural forests and to determine which species diversity measure is more important to tree carbon storage: richness or dominance. We used redundancy analyses to partition the effect of these sources of variation on tree carbon storage. We showed that together, environment, space, and diversity accounted for 43 percent of tree carbon storage, where diversity (19%) alone is the most important source of variation and explained more variation than space (13%) and environment (1%) together. Therefore, even in natural forests where substantial environment and spatial variation can be found, it is still possible to detect the effect of diversity on ecosystem function at scales relevant to conservation. Moreover, both richness and dominance are important to explain the variation on tree carbon storage in natural forests suggesting that these two diversity measures are complementary. Thus, tree diversity is important to predict tree carbon storage in hyperdiverse forests.