Decomposition of leaf litter of Ochroma pyramidale (Malvaceae)

Résumé 0

The tree Ochroma pyramidale is used to recover jungle areas that have been cultivated. This native species generates a thick layer of leaf litter that remains for several years. The objectives of this study were: 1) to know how much leaf litter is produced, 2) to estimate how long it persists in the soil, and 3) to identify the role of soil fauna in its decomposition. Leaf litter production was estimated at 11 Mg/ha/year, while over the course of 13 years the biomass and depth of the leaf litter layer measured in three sites previously planted with Ochroma showed a decrease of over 60%. In a leaf litter decomposition experiment, 37% of biomass was lost in 180 days. Soil mesofauna reduced the concentration of cellulose in leaf litter, while lignin decreased due to the time of permanence of the leaf litter in the soil. The high C:N proportion of the leaves, together with high lignin concentrations, could explain the low levels of loss and accumulation of biomass.