Grant: Discovery Grants Program - Individual

Mangroves are considered one of the most productive ecosystems in the world, serving both terrestrial and marine food webs as well as acting, for marginalized peoples of tropical coasts, as an essential local renewable resource and barrier against tsunamis, sea-level rise and storm surges. However, these forested wetlands are experiencing annual rates of loss that exceed that of terrestrial tropical rainforests. One main limitation to their protection is the inability to receive updated information regarding the extent and condition of many of these forests. Consequently, a focus of my proposed research is to assess whether new space-borne sensors, including Canada's Radatsat-2, can be used to extract vital biophysical parameter data (e.g. tree height, tree density, biomass) from these stands. Able to image at night and through clouds, these radar satellite are now equipped with sensors that could possibly, for the first time, allow highly accurate mapping of mangroves in quasi-permanent cloud covered regions. One of the major causes of mangrove loss is upland water diversion projects (e.g. dams). Consequently, I also intend to model relationships between changing hydrological data for two of the world's largest rivers and their mangrove forests using historical in situ and satellite data. Recent studies on the use of mangrove forests by local inhabitants indicate that these people depend on mangrove timber for a variety of uses. The results of these studies also indicate that factors such as species composition, stem size and distance from settlements could explain the extent of harvesting occurring for select parts of these forests. I propose to develop a unique spatial database to identify and predict areas for local mangrove harvesting. This tool will be based on the integration of various sources of data including information derived from satellites and knowledge gathered from local fishermen. Finally, I intend to assess the potential use of dendrochronology (i.e. tree ring dating) for identifying specific historical causes of mangrove forest degradation. In particular, I anticipate that changes in tree ring characteristics will reflect past perturbations and thus assist researchers in identifying key causes of mangrove loss.