STRUCTURE OF THE TEMPERATE GALLERY FOREST IN SIERRA DE QUILA, JALISCO

Abstract

Sierra de Quila protected area in Jalisco has an extensive network of permanent and temporary creeks where the gallery forests maintain important ecological and biological connectivity processes. This paper describes the tree structure of the flora of seven creeks located at altitudes between 1 876 and 2 200 m. 29 sampling sites of 500 m2 each (1.45 ha) were established, and all the woody individuals with a diameter (ND) of >7 cm were measured. 881 trees belonging to 35 species of 17 families were registered; the dominant taxa included Alnus acuminata, Clethra hartwegii, Pinus devoniana, Prunus serotina, Styrax ramirezii and Salix bonplandiana. The specific richness ranged between 10 and 12 according to the locality, while the Shannon-Wiener diversity index was 1.8 to 2.6 nats, and the Simpson dominance index was 0.12 to 0.48. The grouping analysis and the non-metric multidimensional scaling analysis (NMDS) showed 40 % of similarity between the floras of the creeks. Differences in the density of broadleaves were observed between sites (p < 0.025); these were confirmed by the dissimilarity both in the average abundance of the taxa between locations with a north-south slope (PERMANOVA, F = 2.45, p = 0.0001) and in the altitudes of the sites (PERMANOVA, F= 1.71, p = 0.004).