Abstract ID: 158

Understanding the Environmental Impacts of Crop Expansion & Intensification: Coupling Remote Sensing of LCLUC with Ecosystems Modeling

Large-scale conversions of natural (forest and cerrado) land cover and pasture to heavily mechanized row-crop agriculture are rapidly transforming the landscape of the southern Amazon. We focus here on land-cover and land-use changes (LCLUC) in human environments dominated by pastures (Rondônia) and row-crops (Mato Grosso) of the southwestern Amazon. This work examines the landscape transformations and biogeochemical impacts of these large-scale land-cover and land-use changes in two steps: 1) detecting changes in land-cover and land-use with MODIS data and remote sensing techniques and 2) estimating greenhouse gas emissions with the Terrestrial Ecosystems Model (TEM) driven by LCLUC information derived from remote sensing and other high resolution regional geophysical data sets. LCLUC information from MODIS analysis for the state of Mato Grosso includes documented increases of row-crop agriculture of 6% from 2001-2005 with an intensification of over 11,000 square kilometers from single cropping to double cropping systems. By comparison, Rondônia experienced a 1% increase in row-crop area and only 20 square kilometers of intensification. Row-crop detection is validated with field data on land-use history throughout the states of Rondônia and Mato Grosso. The final and yet-to-be completed step in the remote sensing analysis is distinguishing crop types informed by MODIS green leaf phenology and known management practices. Initial results from crop detections will be presented here. We have begun to incorporate these LCLUC data sets into TEM and have preliminary parameterizations for the dominant land covers and land uses. Of particular interest to us is how N2O fluxes between the land and the atmosphere are affected by land-cover changes and agricultural management practices including the addition of nitrogen fertilizer to row crops such as maize. Here we will present some early results from our coupling of crop expansion detected with remote sensing with N2O emissions estimated by TEM for the State of Mato Grosso.

Session:  LCLUC and Human Dimensions - Current and future trends of land-use/land-cover change and agricultural intensification.

Presentation Type:  Oral