Fire in the Peruvian Amazon.
The risk of fire could increase across large parts of the Amazon rainforest due to increasing incident of drought, expansion of road networks, and rural outmigration, said a scientist speaking at the annual meeting of the Association for Tropical Biology and Conservation (ATBC) in Bonito, Brazil.
Maria Uriarte of Columbia University presented research on fire occurrence and frequency in the Peruvian Amazon using data from NASA’s MODIS system. She and her colleagues found that fire risk increases with drought and the proximity of roads, results consistent with studies elsewhere in the world. Surprisingly, the researchers also found a link between fire and rural outmigration. In other words, when small farmers abandon their plots and move to cities, the rate of burning goes up. Depopulation provides no relief for the Amazon.
Digger deeper into the counterintuitive result, Uriarte found a greater number of neighboring farms is associated with lower fire risk. While small farmers use fire in Peru, they also control it, often in cooperation with neighbors.
“Owner absenteeism leads to greater fire risk,” she said.
Given that all Amazon countries (excluding French Guiana) are expecting rural population decline in coming decades, the findings suggest another fire risk factor in the region, which is already experiencing more fires as a consequence of warmer, drier conditions related to a warmer tropical Atlantic, and expanding road networks, which attract industrial agricultural development and cattle ranches that often employ fire for land-clearing.
But Uriarte said there are potential solutions, including setting up an early warning system for vulnerable locations and populations, creating incentives for people to stay in rural areas, and encouraging ranchers and farmers not to employ fire in land use activities.
Fires in the Amazon have emerged as a global concern due to the large emissions they produce. Even small surface fires have an impact: other studies (including research presented at the ATBC conference by Paulo Brando of IPAM) have shown that Amazon rainforest can quickly transition to savanna after only two or three small surface fires — the type of fires most likely to escape from pasture and agricultural areas.
12/12/12 Update: This paper was formally published in PNAS in December 2012. CITATION: María Uriarte, Miquel Pinedo-Vasquez, Ruth S. DeFries, Katia Fernandes, Victor Gutierrez-Velez, Walter E. Baethgen, and Christine Padoch. Depopulation of rural landscapes exacerbates fire activity in the western Amazon
PNAS 2012 ; published ahead of print December 10, 2012, doi:10.1073/pnas.1215567110
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