LITTERFALL, LITTER DECOMPOSITION AND MAIZE BIOASSAY OF MULCHES FROM FOUR INDIGENOUS TREE SPECIES IN MIXED AND MONOSPECIFIC PLANTATIONS IN COSTA RICA

Abstract

SUMMARY Three plantations with native timber species were established in the Atlantic humid lowlands of Costa Rica to compare growth and nutrient cycling in pure and mixed stands. As part of the project, leaf litter decomposition, litterfall and accumulation of leaf litter on the plantation floor were studied in a young plantation of Pithecellobium elegans D. C. Benth, Genipa americana L., Vochysia ferruginea Mart., and Hyeronima alchorneoides Fr. Allemao. Of the four species studied, V. ferruginea had the highest annual litterfall (867.6 g m-2), G. americana had the lowest (386.7 g m-2), and the mixed plots had an intermediate level (660 g m-2). P. elegans ‘leaves decomposed the most rapidly, V. ferruginea's leaves decomposed the slowest, and the mixed litter decomposed at an intermediate rate. Mulch bioassays testing maize seedling growth showed higher survival and growth rates than the unmulched control in every treatment except for the G. americana mulch. Overall, P. elegans appears to be a good candi...