Resumen

ZARCO-ESPINOSA, VM; VALDEZ-HERNANDEZ, Jl; ANGELES-PEREZ, G  y  CASTILLO-ACOSTA, O. Structure and diversity of arboreal vegetation in the Parque Estatal Agua Blanca, Macuspana, Tabasco. Universidad y ciencia [online]. 2010, vol.26, n.1, pp.1-17. ISSN 0186-2979.

The diversity and structure were analysed for the species of trees in four 50 x 50 m (0.25 ha) sampling units (SU) randomly established in the central-western area of the "Parque Estatal Agua Blanca" (PEAB), Macuspana, Tabasco. Dasometric variables of all individuals with a diameter at breast height > 1 cm were registered, including the vertical stratification and horizontal distribution. The structural importance and diversity indices were calculated. The vegetation presented two well defined strata: lower (< 9 m) and higher (> 9 m), whereas the horizontal distribution of the specimens was generally random according to the Morisita index (Ι_σ). A total of 71 species were identified, belonging to 57 genera and 40 families. The Meliaceae family was the richest in species (14), followed by Fabaceae (8) and Moraceae (7). The genus Chamaedorea (Arecaceae) and the species Rinorea guatemalensis (Violaceae) and Astrocaryum mexicanum (Arecaceae) had the greatest values of structural importance. In accordance with the Margalef (D_α) and Shannon (H') indices, the richness and diversity of species were significantly (p < 0.05) lower in SU4 than in SU1, SU2 and SU3, which were statistically similar. Compared with other tropical rainforests in Mexico, the PEAB had intermediate values with respect to the number of trees per hectare, low values for species richness and intermediate values for Fisher's α diversity.

Palabras llave : Vertical stratification; horizontal distribution; structural indices; species richness.