understanding the environmental impacts of crop expansion & intensification gillian galford, j....

Understanding the Environmental Understanding the Environmental Impacts of Crop Expansion Impacts of Crop Expansion

& Intensification& IntensificationGillian Galford, J. Melillo, J. Mustard, C.E.P. Cerri

Nov 20, 2008Amazon In Perspective: Integrated Science for a Sustainable Future

(LBA/GEOMA/PPBio)

Potential Natural Vegetation: Mato Grosso

F. Mello, CENA MSc.

Detecting croplands & management1. Study Area,

field data

2. MODIS EVI time series

3. Wavelet smoothing

4. Statistics from

wavelet-smoothed time series

5. RESULTS:Spatial & temporalcropping patterns

Galford et al. 2008

Cropland expansion• 2001-2006: Croplands increased from 48, 300 km2 to 110, 000 km2

Galford et al. In Prep

2001-2006 Cropland expansion

Galford et al. In Prep2.5 x106 ha in cerrado0.9 x106 ha in cerradão2.8 x106 ha in forest

Estimated Average Annual GHG Emissions from Expansion

Intensification is the change from single to double cropping patterns.

• We track cropping patterns within cropland areas.

• Single crops typical represent soy or rice.

• Double cropping entails two crops in a single wet season; generally, soy followed by corn, millet, or sorghum.

• 85% overall accuracy

Galford et al. In PrepValidation data thanks to J.C. Brownand C. Stickler

2001 2006

2001-2006 Cropland intensification

Galford et al. In Prep1.4 x 106 ha in cerrado 0.2 x 106 ha in cerradão 0.7 x 106 ha in forest

Estimated Annual Average Potential GHG Emissions Avoided

by Intensification

Galford et al. In Prep

Considering the human dimension

• What explains patterns of expansion & intensification?– How do social factors such as land

tenure differences affect the choice between agricultural intensification and forest conversion?

– How strongly are decisions affected by natural landscape features?

• Potential of annual monitoring (crop area/type)

Conclusions• Remote sensing: a tool for detecting croplands• Impacts of expansion >> intensification

– Trajectories of land-use change are important– Long- and short-term dynamics yet to play out?

• Spatially explicit modeling with TEM

Funding support: NASA/LBA & NASA/ESS Graduate Fellowship ProgramThanks to colleagues, J.C. Brown, C. Stickler, F. Mello