Mapping plant functional types in floodplain wetlands: An analysis of C-Band polarimetric SAR data from RADARSAT-2

The inclusion of functional approaches on wetland characterizations and on biodiversityassessments improves our understanding of ecosystem functioning. In the Lower Paraná Riverfloodplain, we assessed the ability of C-band polarimetric SAR data of contrasting incidence anglesto discriminate wetland areas dominated by different plant functional types (PFTs). UnsupervisedH/and H/A/Wishart classifications were implemented on two RADARSAT-2 images differingin their incidence angles (FQ24 and FQ08). Obtained classes were assigned to the information classes(open water, bare soil and PFTs) bya priorilabeling criteria that involved the expected interactionmechanisms between SAR signal and PFTs as well as the relative values of H and. The productobtained with the shallow incidence angle scene had a higher accuracy than the one obtained with thesteep incidence angle product (61.5%vs.46.2%). We show how a systematic analysis of the H/A/space can be used to improve the knowledge about the radar polarimetric response of herbaceousvegetation. The map obtained provides novel ecologically relevant information about plant strategiesdominating the floodplain. Since the obtained classes can be interpreted in terms of their functionalfeatures, the approach is a valuable tool for predicting vegetation response to floods, anthropicimpacts and climate change.