Resumo

LOZANO-GARCIA, Ma. del Socorro; CABALLERO, Margarita  e  ORTEGA, Beatriz. Evidence of human impact and natural climatic change in 'Los Tuxtlas' region, a multidisciplinary approach. TIP [online]. 2007, vol.10, n.2, pp.49-55. ISSN 1405-888X.

Documentation of past environmental changes in centennial and millennial scales offers information regarding the factors that affects ecosystems. We present evidences of human impact and climate change using the record of several proxy data, magnetic susceptibility, total organic carbon, pollen and diatoms from a lacustrine sequence which covers the last 2000 years. The sequence was obtained from Lago Verde located in Los Tuxtlas region, on the tropical lowlands of the Gulf coasts. Based on multiproxy analyses, two phases of human impact in the basin of Lago Verde are evident. During the Classic period dry conditions are documented with important deforestation, evidence of agriculture activity, fires, high erosion rates and low lake level. Starting at 1960 a second phase of human impact occurs but under a different climatic scenario, with humid conditions and higher lake levels, but also agricultural activity and intense deforestation.

Palavras-chave : Human impact; tropical ecosystems; proxy data; pollen; diatoms.

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