The Decomposition of Leaf Litter in Jamaican Montane Rain Forests

Abstract

The accumulation and decomposition of litter were studied over 2 separate years in 4 montane rain forests (Mor Ridge forest, Mull Ridge Forest, Wet Slope forest and Gap forest) at .apprx. 1550 m altitude in Jamaica. Mean standing crop of leaf litter ranged from 8.1-11.7 tons/ha. Mean decomposition rates for the standing crop of leaf litter at the 3 sites on level ground were as follows: Gap forest, 68% yr-1; Mull Ridge forest, 45% yr-1; and Mor Ridge forest, 44% yr-1. For freshly fallen leaves, decomposition varied between species (15 studied) from 27% to > 96% yr-1, was not affected by site of collection, but was affected by site of decomposition in 1 yr (of 2), was slower in drier periods, was positively correlated with the N and P concentrations of mature leaves, and was not significantly correlated with various anatomical features of the leaves. Data for a range of tropical rain forests suggest that the rate of decay of the standing crop of leaf litter parallels the net primary productivity and stature of the forest, irrespective of altitude.