Publication Date
1993
Description
The South American Chaco, covering more than 1.2 million km2, is second only to the Amazonian natural savanna region. It is the southern extension of the vast savanna zone of the continent, ranging 2000 km on either side of the Tropic of Capricorn. In its pristine state it presented vast pastoral and forestry resources, but in less than 120 years, these resources have been devastated by their uncontrolled exploitation. For most of the drier half of the region the productivity has declined to very low levels. The pastoral resources were decimated by uncontrolled livestock grazing of cattle, sheep, goats, pigs, horses and donkeys, without any boundary constraints and extended over the landscape by the dispersion of ponds and wells for livestock and domestic watering. This overuse of the grazing resource meant the loss of fuel for dry season fires, which was the basic factor maintaining the savanna structural identity. Without fires woody shrubs and bushes encroached upon the grassland understorey, and because of the greater grazing pressures on the edible materials these bush and shrublands became increasingly dominated by unpalatable plants. The forest resources were decimated by uncontrolled cutting of the valuable timber trees for railway sleepers for the new railroad building impetus, fence posts for the heavy demands by the farms on the Pampa and fuelwood as charcoal for domestic and particularly industrial use in smelting and on the railway. As the forest was opened up, grazing by livestock followed, but this prevented the regeneration of the forest tree stocks so that a similar degradation to unpalatable bush and shrubland occurred. These processes of degradation are widely evident in many of the world's savanna lands, but the rapidity with which this has occurred in the Chaco and the degree of the degradation is almost without parallel. The return to a sustainable productive state is not just a biological research problem but a national, political, social and human problem.
Citation
Toledo, Carlos Saravia, "The Chaco savanna lands of South America with particular reference to the processes of degradation in their pastoral and forestry resources" (2024). IGC Proceedings (1993-2023). 1.
https://uknowledge.uky.edu/igc/1993/session10/1
Included in
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The Chaco savanna lands of South America with particular reference to the processes of degradation in their pastoral and forestry resources
The South American Chaco, covering more than 1.2 million km2, is second only to the Amazonian natural savanna region. It is the southern extension of the vast savanna zone of the continent, ranging 2000 km on either side of the Tropic of Capricorn. In its pristine state it presented vast pastoral and forestry resources, but in less than 120 years, these resources have been devastated by their uncontrolled exploitation. For most of the drier half of the region the productivity has declined to very low levels. The pastoral resources were decimated by uncontrolled livestock grazing of cattle, sheep, goats, pigs, horses and donkeys, without any boundary constraints and extended over the landscape by the dispersion of ponds and wells for livestock and domestic watering. This overuse of the grazing resource meant the loss of fuel for dry season fires, which was the basic factor maintaining the savanna structural identity. Without fires woody shrubs and bushes encroached upon the grassland understorey, and because of the greater grazing pressures on the edible materials these bush and shrublands became increasingly dominated by unpalatable plants. The forest resources were decimated by uncontrolled cutting of the valuable timber trees for railway sleepers for the new railroad building impetus, fence posts for the heavy demands by the farms on the Pampa and fuelwood as charcoal for domestic and particularly industrial use in smelting and on the railway. As the forest was opened up, grazing by livestock followed, but this prevented the regeneration of the forest tree stocks so that a similar degradation to unpalatable bush and shrubland occurred. These processes of degradation are widely evident in many of the world's savanna lands, but the rapidity with which this has occurred in the Chaco and the degree of the degradation is almost without parallel. The return to a sustainable productive state is not just a biological research problem but a national, political, social and human problem.
