Patrones de diversidad y aspectos etnobotánicos de las plantas arvenses del valle de Tehuacán-Cuicatlan: El caso de San Rafael, municipio de Coxcatlán, Puebla

Abstract

This study documents floristic composition, richness, diversity and traditional knowledge of the weeds inhabiting milpas (cornfields) of San Rafael, Municipality of Coxcatlan, Puebla. According to previous studies, 4 hypotheses were tested: 1), species richness and diversity of the weeds of San Rafael are similar to those recorded in other cornfields in several sites of the Tehuacan-Cuicatlan Valley; 2), more than 50% of the weeds of San Rafael are used and mainly as fodder; 3), some of the weeds are being submitted to 1 or more of the traditional management practices (v.gr. tolerance, protection, or enhancement) and 4), older farmers possess more knowledge about the weeds. Twelve cornfields were sampled using Canfield's lines, and 20 farmers aged 32-80 were interviewed. Forty two species of 12 families of vascular plants were found. This is an intermediate value with respect to the species richness (5-90 spp.) recorded for other sites in the Tehuacan Valley. Average species richness of weeds in the cornfields studied was between 6 and 17(x̄= 10.3 σ = 3.63), whereas the values of Shannon Index were between 0.795 and 2.209 (x̄= 1.494 σ = 0.4440), which is within the limits expected for weed communities. Farmers recognized between 20 and 31 species and there were not a significant correlation between farmer age and the number of plants they identified. Only 11 species were recognized as useful, and there were not evidences of handling for any of them. According to these results, only the hypotheses 1 and 2 could be corroborated, which suggests it is not yet possible to establish generalizations for the topics analyzed for weeds in this study.