Characterising Reedbeds Using LiDAR Data: Potential and Limitations

Reedbeds are dominated by a small number of plant species, but are extremely valuable habitats for faunal biodiversity. However, reedbeds often exist in small patches distributed across landscapes and for most regions there is a lack of information about their location and condition. This paper investigates the potential of using LiDAR-derived elevation and intensity data to characterise reedbeds. A Leica ALS50 was used to acquire data for reedbeds during the leaf-off phenological period and the study site encompassed a wide range of canopy development. For reedbeds there was a lack of multiple LiDAR returns and ground returns, which limited the ability to acquire information on canopy structure or terrain elevation. Nevertheless, the first return LiDAR data was able to generate an accurate digital surface model and subsequent canopy height model, as validated using field measurements (RMSE 0.47 m; average difference 0.09 m (5% of average height)). LiDAR intensity data displayed specular reflection effects within reedbed areas, but off-nadir imagery was successfully used for mapping reedbeds, non-reedbed vegetation and water bodies.