Toward the sustainable harvesting of epiphytic bromeliads: a pilot study from the highlands of Chiapas, Mexico

For the immediately threatened forests and bromeliads in the highlands of Chiapas, Mexico, we suggest an empirical approach to attain sustainability in the gathering of bromeliads for home decoration. On the basis of theoretical considerations and the results from a pilot study in three forest stands along a disturbance gradient at La Florecilla, we propose that harvesting should be limited to populations (1) that have a density no less than 9000 large rosettes/ha, (2) that are evenly distributed in space, and (3) that grow in the lower stratum of the forest, thus having little effect on their reproductive capacity. In a second study at La Florecilla we used a plotless point-centred quarter method to estimate the population density and homogeneity in spatial distribution of all species of bromeliads in the structurally heterogeneous forest. We found one species, Tillandsia vicentina, that met the prerequisites, having both a satisfactory average population density of ca. 24,000 large ( > 20 cm) rosettes/ha on oaks and a spatially even distribution. We estimate that an annual harvest of 112,000 rosettes of T. vicentina from the lower stratum of the 160 ha forest at La Florecilla can be maintained, in a 4-year rotation cycle. The implementation of a monitoring program should be included in any management plan. (C) 2001 Elsevier Science Ltd. All rights reserved.