Resumo

DIAZ GALLEGOS, José Reyes; GARCIA GIL, Gerardo; CASTILLO ACOSTA, Ofelia  e  MARCH MIFSUT, Ignacio. Land-use and transformation of a tropical forest in an ejido at the Calakmul Biosphere's Reserve, Campeche, Mexico. Invest. Geog [online]. 2001, n.44, pp.39-53. ISSN 2448-7279.

The transformation of the tropical forest in the La Guadalupe ejido (rural farming community) located at the Calakmul Biosphere's Reserve (CBR), was evaluated for the period between 1970 and 1995 using historical and geographical approaches as well as a Geographic Information System (GIS). The ejido comprised an area of 4 919 ha, 59% of which corresponds to the nuclear zone of the CBR, and 33% to the buffer zone. Three forest types, three types of secondary vegetation, riparian vegetation, and five-land use types were recognised. These were distributed along three landscape units: steep slopes, flat slopes, and lowlands. The largest surface area was occupied by medium semi-evergreen forest (1 846.5 ha), followed by low semi-evergreen forest (1 484.5 ha). A recent transformation (within 15 years) of the primary forest in the ejido was observed, with 1 244 ha of secondary vegetation, 617 ha of which was between one to two years old, and 588 ha between seven and nine years old. Subsistence agriculture was practiced on 225 ha in the ejido, with and beginning farming of the jalapeño pepper. The largest forest transformation occurred in the medium semi-evergreen forest type which has lost 1 244.3 ha from 1970 to 1995 at a deforestation rate of 5% per year. The tall forest type completely disappeared during this period. The forest cover was converted into agricultural land. The low forest was almost not affected due to the edaphic and hydrolagic restrictions for agricultural use associated to it. Demographic growth (8.6%) has been the most important factor contributing to the transformation of forest cover in the ejido.

Palavras-chave : GIS; tropical rain forest; semi-evergreen forest; land-use; deforestation; Calakmul.