COMPOSITION, STRUCTURE, AND MANAGEMENT POTENTIAL OF SECONDARY DRY TROPICAL VEGETATION IN 2 ABANDONED HENEQUEN PLANTATIONS OF YUCATAN, MEXICO

Data on the composition and stand dynamics of abandoned henequen (Agav e fourcroydes) fields of different ages are presented and their manage ment potential discussed. The study was carried out in the Hacienda of Kancabchen, Yucatan, Mexico in 12- and 26-year-old secondary forests. Species richness and diversity were greater as the stand grew older, Even though 73% of species have the capacity to regenerate from coppic ed shoots, only between 30 and 50% of the individuals actually regener ate from coppiced shoots in both communities, respectively. According to the Sorensen similarity index both stands are similar in compositio n (73%), while the Motyka index indicates that they differ in biomass distribution (17%). This could be due to soil conditions and the manag ement of these areas, or a combination of both. The 26-year-old abando ned henequen stand still has pioneer species dominating and has very f ew late successional species present. Slow-growing tree species on the 26-year-old stand were expected, but their absence could be due to th e lack of seed sources, a limited dispersal capability, or to an arres ted succession due to human perturbation and management. Eight species dominated the stands, accounting for more than 60% of the total impor tance values. Most species present in both stands are widely used loca lly and are commercialized inside the rural communities. Potential man agement strategies could involve forest thinning to remove competition and favor those species used by the communities, those with potential to increase soil fertility, and those that could have semi-commercial purposes. Management could also include enrichment with other species such as Cedrela odorata and Apoplanesia paniculata that are widely us ed and were previously present as part of the native vegetation of the area. (C) 1997 Elsevier Science B.V.