Litterfall from tropical dry forest trees scattered in pastures

Abstract

Introduction: Scattered trees from tropical dry forests (TDF) deposit significant amounts of leaf litter into pasture soils. Objective: To estimate the litterfall production during the dry season by scattered Lysiloma acapulcense (Kunth) Benth. and Vachellia pennatula (Schltdl. & Cham.) Seigler & Ebinger trees in pastures. Materials and methods: Ten scattered trees of each species were selected from a 10-ha pasture, and litter was collected during the dry season (November to May) and sorted into fractions. Leaf litter biomass, nitrogen (N) and lignin (L) content, and the lignin-nitrogen (L/N) ratio were assessed. Leaf litterfall was modelled over an annual cycle using a double logistic model. Means from all variables were compared between species using a t-test. Results and discussion: Litter, nitrogen and lignin content were similar between species. However, the L/N ratio was significantly higher (P < 0.0001) in L. acapulcense (32.1) than in V. pennatula (21.3). The leaf litter model showed that the defoliation phase of L. acapulcense lasted 30 days longer than that of V. pennatula. Conclusion: The quantity and quality of leaf litter that scattered trees deposit in a pasture encourages the adoption of agroforestry systems, including tree species native to TDF.