Management compromises and the sustainability of palm populations in Mayan homegardens

Abstract

The sustainability of a homegarden can be evaluated not only as its species richness and eco-systemic role, but also as the result of management practices affecting resource sustainability. Sabal spp. have been managed since Colonial times into homegardens, at present, its mature leaves are mostly used in roof building of traditional Mayan homes. Along a three-year study, we evaluated management sustainability of Sabal yapa and S. mexicana populations in two homegardens of Maxcanú, Yucatan, Mexico by the use of prospective and retrospective demographic analyses. We calculated sustainability based on population growth rate (λ). We used the prospective elasticity model to estimate the more sensible vital rates of the palm populations, and the retrospective analysis to calculate the effect of management practices on the annual variation of the palms population λ values. Care of young plants and occasional seed planting were among the management practices that increased the density of palms having an adequate harvesting size. The stages of the palms' life cycle that are critical for sustainable population management are the adult and juvenile stages. An event of felling of adult palms had a negative effect in the population's sustainability. Other practices in the homegarden such as weeding and watering of fruit trees increased the probabilities of survival. Our study showed that the management of natural resources in homegardens involves compromises, and is not always focused on the sustainability of specific resources, but rather on the integrated management of the agroforestry system.