RATES OF DEFORESTATION IN LOS-TUXTLAS, A NEOTROPICAL AREA IN SOUTHEAST MEXICO

On the basis of ground surveys, aerial photographs (for 1967 and 1976), and satellite imagery (for 1986), maps of rain forest distribution were developed for the northern part of the Sierra de Los Tuxtlas (Veracruz, southeast Mexico). Forest coverage maps for 1967, 1976, and 1986 show dramatic deforestation proceeding up from the lowlands, with the remaining natural vegetation now increasingly restricted to the high, steep, and less accessible parts of the Sierra. From the digitizing of the maps it was estimated that (1) during the nearly 20 years of this analysis the vegetation was reduced by 56%, and (2) by early 1986, approximately 84% of the original forest area had been lost. The derived annual deforestation rates (expressed as the percentage of remaining forest that is cleared per year) were 4.2% for the interval 1967-1976 and 4.3% for 1976-1986. Were these trends and rates to continue, only 8.7% of the original vegetation would persist by the year 2000, and then only in the form of an archipelago of very small forest fragments, of which the largest would be the now-protected areas (e.g., the Los Tuxtlas Biological Station, with only 640 ha), and the most inaccessible tracts. Immediate action is urgently needed to protect these small but rich remnants and preserve them as foci of potential biological inocula for future ecorestoration of these, the northernmost tropical forests on the continent.