Woods Hole Research Center

The cerrado, or savanna, ecosystem is the second largest biome of tropical South America. Although deforestation of the Amazon rainforest has received much attention, most of the Brazilian deforestation has taken place, and continues to take place, in the savanna environments outside of the Amazon basin. The cerrado is considered a hot spot for biodiversity and is the headwater region of major rivers of eastern South America. Of the original 2,000,000 km² of cerrado that existed in Brazil before 1940, about 50 percent has been converted and fragmented by deforestation and expansion of the agricultural frontier, compared to about 10 percent of the tropical rainforest.

Cattle ranching is currently the single largest use of cleared land in the cerrado, covering about 68 percent of total deforested area. However, the rising price of petroleum and the growing global demand for soybeans have stimulated rapid expansion of areas planted in sugarcane and soybeans. Ethanol production from sugarcane is forecast to increase by 150 percent by 2017, necessitating an increase in sugarcane planted area from the current 3 million hectares to 9.7 million. Much of this expansion will take place in the core cerrado environment in the vicinity of two new ethanol pipelines, one from southern Goiás to São Paulo, the other from central Mato Grosso do Sul and Paraná.

It has been argued that this sugar cane expansion will have limited environmental impact because it will take place on degraded pasturelands. However, no systematic analysis of the suitability of degraded pastures or of the remaining native cerrado for sugar cane expansion has been done.  A large portion of degraded pasture is not suitable for sugarcane production and thus, future sugar cane expansion will most likely occur in areas of cerrado currently in native vegetation. Therefore, much of the remaining cerrado is at serious risk of deforestation from expanding biofuel demands.

In this project, a team of remote sensing experts, economists, hydrologists, and biogeochemists will quantify the socio-economic drivers of sugarcane expansion, the amount of cerrado land suitable for sugar, the potential trajectories of future deforestation, and the environmental impacts of land-use change.

The following are anticipated outcomes from this project, which began in early 2011.

• The area of degraded pasture and of land suitable for sugarcane will be derived from satellite, census, and spatial data from Landsat, MODIS, and ALOS products.
• A range of scenarios for future expansion in the cerrado onto all land cover types will be created by integrating our macroeconomic model of drivers of land-use change with a spatially explicit deforestation model.
• The carbon consequences and the net effect on N₂O and CH₄ emissions from historical deforestation and each future scenario will be calculated using a book-keeping model based on summaries of changes in C stocks and gas fluxes.
• Finally, the individual and combined influences of future land cover changes on the hydrology of the cerrado will be calculated with our coupled vegetation, surface hydrology, and climate models.

This project is a collaborative effort between The Woods Hole Research Center (led by Michael Coe), the Federal University of Goías, Brazil (Laerte Ferreira Jr, and Manuel Ferreira), the Federal University of Minas Gerais (led by Britaldo Soares Filho) and IPAM (Paulo Brando).

This project is funded by the NASA Land-Cover/Land-Use Change Program (LCLUC).

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