Tropical dry forest recovery after long term Henequen (sisal, Agave fourcroydes Lem.) plantation in northern Yucatan, Mexico

Low-stature tropical dry forests are some of the most threatened ecosystems on a global level. Only recently have studies been conducted to characterize them. Little is known about their recuperation after perturbation. In the state of Yucatan on the Yucatan Peninsula, Mexico, the cultivation of Henequen (Agave fourcroydes Lem., sisal) substituted a great portion of the low-stature deciduous forest during the 20th century. However, crises in the fiber market led to an almost total abandonment of it. The vegetation has recovered during this time, but we do not know what the effect of many years of management has been. A study of the structure and composition of the low-stature deciduous forest and successional states derived from it after the abandonment of the Henequen cultivation was undertaken. The vegetation was analyzed in five localities and three successional states: <10 years (SSI), >10 and <15 years of abandonment (SS2), and low deciduous forest or advanced successional state (>20 years, SS3). The richness of woody species as well as diversity (Shannon's index) were lower in the early and intermediate states than in the more mature state. In general, the floristic similarities are low between states and between sites. The oldest plots showed greater similarity with regard to the abundance of species. Species dominance is distinct in each site and each successional state, especially in the very young ones. The long history of use has favored a group of species with the capacity to sprout after perturbation. Lack of propagules due to fragmentation and perturbation are reasons for the impoverishment of species. The recovery of the low-stature deciduous forest of northern Yucatan will be difficult if the remnants of old forest, which could function as seed sources, are not preserved. (C) 2002 Elsevier Science B.V. All rights reserved.