EVALUATION OF AN AGROFORESTRY SYSTEM “TREES ON FARMLANDS”, IN VICENTE GUERRERO, TLAXCALA, MÉXICO

Abstract

The biological and economical advantages derived from an agroforestry system in Vicente Guerrero, Tlaxcala are evaluated, by determining the structure, botanical composition of the vegetation and the rent . Plant identification of nine plots , established in terraces, contour lines, plus native vegetation and the patches of vegetation, was carried out, in 10, 4 y 1 m² unit employed for trees, shrubs and herb, respectively. Botanical composition, density, diameter at breast height, cover and height of the individuals were recorded and used to elaborate vegetation profiles, estimate the importance value and a comparison of plots with indexes riches (Margalef), indexes diversity (Simpson, Shannon-Wiener), as soon as similarity indexes (Jaccard, Sørensen) and multivariable analisis (UPGM, and principal components analysis. The financial valuation used the Cost/Benefit ratio (C/B) and the net current value (NCV). The results indicated a total of 153 taxa; the families best represented were Asteraceae, Poaceae and Fabaceae; the best represented functional group was herbs with 119 taxa. Cenchrus multiflorus Presl., Chloris submutica H.B.K. y Pennisetum clandestinum Hochst.ex Chioy for herbs, Agave salmiana Otto ex Salm-Dick y Haplopappus venetus (HBK.) Blake for shrubs and Juniperus deppeana Steud. and Prunus persica (L.) Sieb. & Zucc. for trees were the species with the highest importance value. The Shannon-Wiener diversity index ranged from 3.55 (plot six) up to 3.85 (plot one). The highest floristic similarity belonged to plots eight and nine (81 to 89 %) according to their similarity indexes and multivariable analysis. Based on the C/B (2.3-7.1) and NCV ($47 002.24- $176 761.65) the agroforestry system is acceptable.