|
|
|
|
Mesoamerica
|
|
|
|
|
|
|
human impacts
Prior to the arrival of the Spanish conquistadores 500 years ago, Mesoamerica supported intensive indigenous agriculture and hunting. With the arrival of Cortez, indigenous populations were decimated by disease, warfare, and slavery, and some of their agricultural clearings were abandoned to regeneration, yielding in some areas a net increase in forest lands. However, during the 19th century, the conversion of forests for large-scale agricultural and livestock developments, including coffee, bananas, oil palm, and beef cattle, began in earnest. Much of the western Pacific plain was cleared by the end of the 1800s, and the focus of conversion during the 1900s was shifted to the tropical moist forests of the Caribbean lowlands.
The advent of mechanized forestry in the 20th century allowed timber operations to abandon rivers and lagoons as the only method of transportation for logs in the topical forests of Mesoamerica. Aside from riparian areas and adjacent areas that could be reached by oxen, most forests had remained intact largely because they were unharvestable with the available technology. Once timber extraction was mechanized, the presence of big-leaf mahogany, even today the most valuable timber species in the Neotropical forest, was a powerful incentive for logging to open virgin forests. Old-growth mahogany trees could be large enough and valuable enough to prompt extensive exploration; their procurement was the beginning of a multitude of pressures on these forests that escalated once they were relieved of their most valuable species.
In recent decades, Mesoamerica has seen some of the highest deforestation rates in the world; between 1980 and 1990, deforestation averaged 1.4 percent annually, and it is estimated that 80 percent of the area's original habitat has been cleared or severely modified. Of all the countries in the hotspot, El Salvador is the most devastated; it has less than five percent of its original forest cover remaining.
Recently, large-scale industrial developments, including oil development in Mexico and Guatemala and timber and mineral extraction, have increased the threat to forests. Deforestation often follows a familiar and devastating pattern in Mesoamerica, driven by inequities in land distribution and very high population growth rates (as high as seven to ten percent per year in some parts of southern Mexico and northern Guatemala). Roads built for development projects open up access to previously pristine lands and serve as migration routes for landless peasants, who clear adjacent lands for subsistence agriculture. Once the lands, which typically have very poor soils, become unproductive, the peasants clear other areas, selling their original plots to consolidators who develop large cattle ranches in their wake.
|
The thick-billed parrot (
Rhynchopsitta pachyrhyncha, EN) once occured in Arizona and New Mexico but is now restricted to northern and central Mexico. The species is suffering rapid decline.
|
|
|
|
|
|
|
|
|
|