Rates of litter decomposition and nutrient release from litter provide valuable information on the capacity of different tree species to replenish soil nutrients in degraded tropical areas. Leaf litter decomposition, leaf litterfall, plantation floor leaf litter, and mulch performance were studied for four indigenous timber species,Virola koschnyiWarb,Dipteryxpanamensis(Pittier) Record and Mell,Terminalia amazonia(J.F. Gmel.) Exell., andAlbizia gua-chapele(H.B.K.) Little, grown in mixed and monospecific plantations in the Atlantic humid lowlands of Costa Rica.Terminalia amazonialitter decomposed the fastest: no litter remained after 6 months. After 12 months,D. panamensis, A. guachapele, and the mixed litter decomposed completely, while 15% of the original weight ofV. koschnyilitter remained. Differences in decomposition rates were closely related to leaf nutrient content. Total annual leaf litterfall was highest inT. amazonia(872.9 g/m2), followed byD. panamensis, V. koschnyi, and the mixed plots.A. guachapelehad the lowest leaf litterfall (236.0 g/m2). The highest plantation-floor leaf litter was found inV. koschnyiandD. panamensis.Both litterfall and plantation-floor litter accumulation fluctuated least in the mixed plots.A. guachapeleandD. panamensismulch most positively affected maize seedling growth, followed by the mixed mulch. Recommendations are drawn from the results to suggest species choice for sustainable land management in the region.