RICHNESS, ABUNDANCE, AND COMPOSITION OF EDIBLE WEEDS IN THREE AGROECOSYSTEMS UNDER DIFFERENT MANAGEMENT IN THE SOUTH-EASTERN AREA OF MEXICO CITY

Abstract

Since pre-Hispanic times, agriculture in Mexico City has developed under different agroecosystems, which have changed the type of crops, agricultural practices, and their physical structure. This study was carried out on the agrobiodiversity of agrestal weeds present in slope, ciénega, and chinampa agroecosystems located in southeastern area of the city. An analysis based on the edible weeds recorded in those agroecosystems is presented. Database of the Comisión Nacional para el Conocimiento y Uso de la Biodiversidad, was analyzed to: a) characterize three agroecosystems of Mexico City, slope, ciénega, and chinampa in terms of their structure, functioning, and the agricultural practices followed there; b) compare the richness, abundance, composition, and importance value of edible weeds, and c) establish possible relationships between agricultural practices in those agroecosystems with these ecological attributes. The three agroecosystems presented changes in the agricultural practices, with the swamp and the chinampa having the most impact. The slope maintains many of the traditional practices. Twenty-six species of edible weeds corresponding to 8 botanical families were record- ed. Species richness, alfa, and beta diversity were similar between the three agroecosystems, as well as the number of native and introduced species. However, PCoA indicated differences in weed composition between the three agroecosystems. The PCA analysis based on the importance value of edible weeds also separated the three agroecosystems, where introduced weeds with the highest importance value separated chinampas. PCA corresponding to agricultural practices and the importance value of edible weeds showed that agroecosystems grouped depending on the soil use, crop preparation, and the Importance Value of edible weeds. Even when edible weeds are present in the three agroecosystems, it is proposed that they function as ecological indicators of their quality and sustainability since changes in their structure, function, and agricultural practices affect some of the weeds ́ ecological attributes analyzed.