Leaf litter dominance components respond to temporal variation in a tropical riparian zone

Temporal scale and biodiversity components define how temporal variation influences biodiversity. For Brazilian Savannah riparian zones, litter input is controlled by rainfall fluctuations among climatic periods, whereas the dominance and diversity components represent the litter biodiversity. We hypothesize that the litter dominance components would respond more to temporal variation. In contrast, the diversity components would differ more among the input compartments due to a heterogeneous riparian forest. We conducted an experiment in a Brazilian savannah riparian forest during four climatic periods, sampling litter dynamics and functional traits once at the beginning of each period and across different input compartments. Sixteen plant species contributed to the litter input during the study; however, only six contributed with ~ 88%of the total litter input. We found an effect of the temporal periods over two dominance components, CWM Phenols and CWM Leaf Width , whereas none of the diversity components responded temporally. For input compartments, we found an effect over one diversity component, Functional Divergence (FDiv), and over two dominance components, CWM Nitrogen and CWM Leaf Width . Our results supported our hypothesis that for this species-rich ecosystem temporal variation affected the dominance components. Interestingly, temporal variation did not affect evenness, whereas the ones that responded were the components that do not assume species equivalence, suggesting that the effect over the ecosystem is based on dominant trait alternation. Likewise, diversity and dominance components responded to input compartments, implying a heterogeneous riparian forest in a reduced local spatial scale, which would affect the decomposer community resource supply.