TRADITIONAL AGROECOSYSTEMS AND GLOBAL CHANGE IMPLICATIONS IN MEXICO.

Global warming is producing negative effects on agriculture, changing the distribution and production of vulnerable crops. This phenomenon could also modify the production and distribution of plant species. Agroecosystems are highly diverse systems which could potentially reduce the impact of climate change. The following research work is founded due to this situation. The main objective of this study is to assess the impact of climate change on an unconventional agricultural system. Agroecosystems in the State of Puebla (Mexico) were analyzed under the horizons of the present, 2020, 2050 and 2080 under different socioeconomic scenarios (A1B, A2A, B1 and B2), to identify which areas could present changes in the distribution of at least 3 species in the State of Puebla. Three races of maize: Conico, Elotes conicos y Tuxpeno (Zea mays ssp. mays) were selected, and the most important crops from the state of Puebla: bean (Phaseolus vulgaris), amaranth (Amaranthus hypochondracus), courgette (Cucurbita pepo), coffee (Coffea arabica), chili (Capsicum frutescens), sugar cane (Saccharum officinarum), potato (Solanum tuberosum), avocado (Persea americana), apple (Malus domestica), peach (Prunus persica), orange (Citrus sinensis), Mexican hawthorn (Crataegus pubescens), and wheat (Triticum spp). We built niche models for some species and determinated the overlap areas (agroecosystems) with special emphasis on maize races. Our results showed an important persistence of different agroecosystems (73% of the territory in Puebla). These systems are likely to increase their surface area under scenario A1B and B1, while in the A2A and B2 scenarios the impact of climate change is greater in agroecosystems. In the first case, agroecosystems lose in average up to 13% of surface area, and 12% for the second scenario. Finally the growth margin is 8% compared to the A1B and B1 models. We determinate vulnerability areas to global change in the southwestern of Puebla (maize origin center) and the north (rainforest protect area). [ABSTRACT FROM AUTHOR]