Cropland expansion changes deforestation dynamics in the southern Brazilian Amazon
- Douglas C. Morton*,
- Ruth S. DeFries*,†,‡,
- Yosio E. Shimabukuro§,
- Liana O. Anderson§,¶,
- Egidio Arai§,
- Fernando del Bon Espirito-Santo‖,
- Ramon Freitas§, and
- Jeff Morisette**
- *Department of Geography, 2181 LeFrak Hall, University of Maryland, College Park, MD 20742;
- †Earth System Science Interdisciplinary Center, University of Maryland, 2207 Computer and Space Sciences Building, College Park, MD 20742;
- §Divisão de Sensoriamento Remoto, Instituto Nacional de Pesquisas Espaciais (INPE), Av. dos Astronautas, 1758 Jardim da Granja, São José dos Campos, SP 12227-010, Brazil;
- ¶Oxford University Centre for the Environment, University of Oxford, South Parks Road, Oxford OX1 3QY, United Kingdom;
- ‖Complex Systems Research Center, University of New Hampshire, Morse Hall, Durham, NH 03824; and
- **Goddard Space Flight Center, National Aeronautics and Space Administration, Mail Code 614.5, Greenbelt, MD 20771
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Contributed by Ruth S. DeFries, July 27, 2006
Abstract
Intensive mechanized agriculture in the Brazilian Amazon grew by >3.6 million hectares (ha) during 2001–2004. Whether this cropland expansion resulted from intensified use of land previously cleared for cattle ranching or new deforestation has not been quantified and has major implications for future deforestation dynamics, carbon fluxes, forest fragmentation, and other ecosystem services. We combine deforestation maps, field surveys, and satellite-based information on vegetation phenology to characterize the fate of large (>25-ha) clearings as cropland, cattle pasture, or regrowing forest in the years after initial clearing in Mato Grosso, the Brazilian state with the highest deforestation rate and soybean production since 2001. Statewide, direct conversion of forest to cropland totaled >540,000 ha during 2001–2004, peaking at 23% of 2003 annual deforestation. Cropland deforestation averaged twice the size of clearings for pasture (mean sizes, 333 and 143 ha, respectively), and conversion occurred rapidly; >90% of clearings for cropland were planted in the first year after deforestation. Area deforested for cropland and mean annual soybean price in the year of forest clearing were directly correlated (R 2 = 0.72), suggesting that deforestation rates could return to higher levels seen in 2003–2004 with a rebound of crop prices in international markets. Pasture remains the dominant land use after forest clearing in Mato Grosso, but the growing importance of larger and faster conversion of forest to cropland defines a new paradigm of forest loss in Amazonia and refutes the claim that agricultural intensification does not lead to new deforestation.
Footnotes
- ‡To whom correspondence should be addressed. E-mail: rdefries{at}mail.umd.edu
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Author contributions: D.C.M., R.S.D., and Y.E.S. designed research; D.C.M., R.S.D., Y.E.S., L.O.A., E.A., F.d.B.E.-S., and R.F. performed research; D.C.M. and J.M. analyzed data; and D.C.M. and R.S.D. wrote the paper.
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The authors declare no conflict of interest.
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See Commentary on page 14261.
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↵ †† Total area planted in soybeans, corn, cotton, rice, sugarcane, and sorghum from municipality data on crop production (IBGE Municipal Agricultural Production, www.sidra.ibge.gov.br).
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↵ ‡‡ Annual deforestation increment from INPE PRODES, www.obt.inpe.br/prodes.
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↵ §§ Data sources: Monthly price paid to soybean producers, Fudaçao Getúlio Vargas Agroanalysis; deflator, IBGE Extended National Consumer Price Index. Prices are shown per 60-kg sack of soybeans to maintain consistency with the common unit of soybean production.
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↵ ¶¶ INPE Detecção de Desmatamento em Tempo Real, or Program for Real-Time Detection of Deforestation, was started in 2003 to provide regular updates of new deforestation >25 ha in the Brazilian Amazon using data from MODIS sensors and CBERS-2, the Chinese–Brazilian Environmental Satellite. Data can be accessed at www.obt.inpe.br/deter.
- Abbreviations:
- ha,
- hectares;
- MODIS,
- Moderate Resolution Imaging Spectroradiometer;
- PRODES,
- Program for the Estimation of Deforestation in the Brazilian Amazon;
- INPE,
- Brazilian National Institute for Space Research
- © 2006 by The National Academy of Sciences of the USA
