Resumen

VAZQUEZ-NEGRIN, Isabel et al. Structure and floristic composition of the tall evergreen forest in the Ejido Niños Héroes, Tenosique, Tabasco, Mexico. Polibotánica [online]. 2011, n.32, pp.41-61. ISSN 1405-2768.

Floristic composition and forest structure were described for the tall evergreen tropical forest of the Ejido Niños Heroes, Tenosique, Tabasco (NHT). We selected four sampling units (U), each of which was set up in a box 50 X 50 m (2 500 m²). In each U all trees with a diameter at breast height breast (DBH) ≥ 2.5 cm were counted and measured for height. Density, frequency, and dominance were determined to get importance value, diversity, and similarity indices. A total of 4 773 individuals, belonging to 112 genera and 196 species, were surveyed and identified. The most abundant families were Rubiaceae, Fabaceae, Sapotaceae, Moraceae, Annonaceae, and Arecaceae. Three strata were established: lower (1 to 10 m), middle (11 to 20 m), and upper (21 to 30 m). Rinorea guatemalensis was the species with the highest value importance (IVI 33.5). The sampling units showed a similar diversity: U3 (H') 3.9, U1 3.6, U2 3.4, and U4 3.3. The Sorensen Similarity Index stated that the units are different in species composition. U3 and U4 are most similar to one another. The NHT forest possesses high abundance, richness, and diversity of species. Although it has been subjected to strong degrading changes, it is still in a state of conservation.

Palabras llave : value importance; vertical strata; arborea diversity; floristic similarity.