Remote Sensing of Soil Carbon and Greenhouse Gas Dynamics across Agricultural Landscapes

Overall impact of GRACEnet management strategies for enhancing soil C sequestration and reducing greenhouse gases emissions requires extending results from small plot or field experiments to regional and national scales. This spatial scaling task is not trivial because the mechanisms controlling carbon, water, and energy exchanges are nonlinear and interact with each other. Remote sensing offers the only practical method to account for the spatial and temporal variability inherent across agricultural landscapes. In this chapter, the fundamental spectral properties of vegetation and soils are reviewed and potential synergies of in situ and remotely sensed measurements for providing frequent, spatially explicit information about agricultural landscapes are examined. Data fusion and assimilation techniques for merging data acquired at different spatial and temporal resolutions and techniques for creating synthetic datasets with high spatial and temporal resolutions are discussed. The next step for verifying GRACEnet practices will be to link process models with these enhanced datasets to reliably describe ecosystem functions at various scales.