NUTRIENT RETURN WITH LEAF LITTER FALL IN LEGUME TREE SPECIES MONOSPECIFIC STANDS

Tropical ecosystems play a key role in global warming and remain underestimated in the global biogeochemical balances. Apart from that, nutrient cycling in forest ecosystem supplies nutrient demand and soil organic matter formation. However, information on nutrient turnover for tropical legume tree species is still lacking. To fill this gap in knowledge, we selected even-aged (27 years old) Plathymenia reticulata, Hymenaea courbaril and Centrolobium tomentosum monospecific stands and evaluated leaf litterfall over one year. Litter was monthly hand-sorted into leaves from the planted species and leaves from other species. The samples were analyzed for C, N, P, K, Ca, and Mg. H courbaril stand produced higher litter annually, but P. reticulata stand showed higher contribution from other species. P. reticulata leaf litter returned greater amounts of N and P. Nutrient return varied broadly regarding litter production and chemistry from the planted species, but leaf litter from the understory vegetation showed a similar pattern across forest stands.