Structure and diversity of a gallery forest in northeastern Mexico

Abstract

The structure and diversity of the tree community of a gallery forest in northeastern Mexico was assessed. In 2017, at Allende municipality, Nuevo León, 15 sampling sites of 10 × 5 m were randomly established, where the individuals of arboreal size with a normal diameter (d_{1.30 m}) ≥ 8 cm were measured. The horizontal structure was evaluated with the Importance Value Index, and the vertical structure, with Pretzsch’s index. For diversity, the Margalef and Shannon-Wiener indexes were calculated. Nine species were registered, belonging to nine genera and nine families. The evaluated community had 2187 N ha^-1 abundance, with 496.3 m² ha^-1 basimetric area. The species with the highest abundance, dominance and frequency was Taxodium mucronatum, with 52.4 % of IVI value followed by Platanus rzedowskii (IVI = 23.2 %) and Carya illinoinensis (IVI = 8.8 %). Pretzsch’s index was 2.03, with a A_max of 3.29 and a A_rel of 61.87, which indicates medium structural diversity in the high strata. The D_Mg value (Margalef index) of the community was 1.52 and average value of 0.58 for the Shannon-Wiener index, which indicate that the evaluated community has low richness and diversity.