Print PageLand-use change, disease, climate change and habitat loss are resulting in species extinction rates up to more than a thousand times faster than historic levels. Meta-analyses have shown that this species loss may have negative impacts on some ecosystem processes such as productivity and nutrient availability. Species extinctions are resulting in changes in both species richness and composition, however, and effects of biodiversity loss may be highly dependent on the identity of the organisms lost. We investigated the importance of plant functional group identity to ecosystem functioning by removing individual plant functional groups from an artificially-created plant community. Removal treatments were imposed during primary succession in a series of experimental annual plant communities. Plant communities were created at natural species densities using seed banks from sand-dunes in the Negev Desert, Israel. As biodiversity loss is happening both in concert with, and as a result of, climate change, the effects of removals were examined in multiple environments created through watering and fertilization treatments. We examined a variety of ecosystem properties including soil moisture, light interception, nutrient availability, and above- and below-ground decomposition rates.
Results/Conclusions
Functional group removals had no effect on light interception relative to controls. In contrast, functional group identity was important in determining soil moisture, but the effect of identity was highly dependent on the resource environment. Forb removal increased soil moisture, but this effect disappeared with additional resources (watering and fertilization treatments). Significant effects of functional group identity were also found for soil nutrients, with forb removal resulting in increases in N and K. Finally, above-ground, but not belowground, decomposition rates were influenced by functional group identity. This study highlights the importance of including both the identity of the species lost and environmental context when predicting impacts of biodiversity loss.
