Remote Sensing of Coastal Wetland Biomass: An Overview

Wetlands are highly productive and provide critical habitat to animals and plants. Coastal wetlands have been affected by human-created alterations and, more recently, by losses due to sea-level rise. To protect and restore tidal wetlands, scientists need to monitor the changes in the wetlands as the sea level continues to rise and the coastal population keeps expanding. Advances in sensor design and data-analysis techniques are making remote-sensing systems practical and cost effective for obtaining quantitative biophysical information, such as wetland extent, live aerial biomass, leaf area index, percentage of canopy closure, etc. This article reviews biomass mapping techniques and illustrates their use for wetland-change detection. The results show that analysis of satellite and aircraft data, combined with a small number of on-the-ground observations, allows researchers to map biomass and determine long-term changes in tidal marshes.