March 31, 2010
Conducting field surveys during the course of 10,000-kilometers of travel along remote Amazon rivers, Luke Parry of Lancaster University found that a sharp decrease in rural habitation has not been accompanied by a decline in harvesting of wildlife and forest resources, indicating that urban populations exact a heavy toll on distant forests through hunting, fishing, logging, and harvesting of non-timber forest products.
"You might think that as people leave the forest there would be a conservation gain - that the abandoned land and rivers would be left to nature. However, we found that wasn't the case. Although plants and animals were no longer being farmed and harvested by subsistence resource users, other more commercial activities moved in," said Parry in a statement.
One of the Amazon river dwellers interviewed by Parry. Photo by Parry.
Parry said that abandoned land was more likely to be colonized by speculators, who cut down forest for cattle pasture, hoping to capitalize on appreciating land values. Under Brazilian law, forest-clearing is one of the easiest ways to gain property rights on unclaimed land.
"When people leave the villages they leave behind a vacuum," he said. "When the land isn't occupied the forest is exposed to the threat of large scale deforestation and unregulated land speculation in abandoned headwaters which is a real possibility in some areas due to expansion of the road network."
Brazil's road network in the Amazon is fast-expanding under the country's infrastructure development plan. Highways like the recently paved BR-319 have greatly improved the viability of ranching and large-scale agricultural production in the region, driving up land prices and fueling speculation, usually by non-residents who follow the resource frontier.
Small-scale forest clearing in the Amazon rainforest.
Small community along the Amazon river.
The authors say the findings cast doubt on the argument advanced by some researchers that rural abandonment would be a boon to conservation by reducing deforestation and allowing forest recovery. Instead, Parry and colleagues argue for providing incentives to stabilize rural populations and promote sustainable use. Payments-for-ecosystem services — like the scheme currently offered by the Amazonas state government — could serve as a means to support such communities.
"For those areas not yet abandoned we encourage efforts to sustain low-density rural populations through the federal or state demarcation of inhabited sustainable use reserves," the authors write.
"When given land tenure, rural people can assist conservation by maintaining forest cover to ensure environmental services such as carbon retention and water cycling, and prevent illegal landgrabbing and violence. Rural people can be key agents in sustaining biodiversity through agro-ecological practices that maximize the matrix value of anthropogenic landscapes."
CITATION: Luke Parry, Carlos A. Peres, Brett Day, & Silvana Amaral. Rural-urban migration brings conservation threats and opportunities to Amazonian watersheds. Conservation Letters xx (2010) 1–9
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