Within-Species Benefits of Back-projecting Airborne Laser Scanner and Multispectral Sensors in Monospecific Pinus sylvestris Forests

Abstract

Back-projecting is an alternative to orthorectification for ALS-imagery fusion. It usually assists in improving forest estimations in mixed forests, by adding species information from optical sensors. In this study, we focused on the within-species advantages obtained. Results showed that estimating relative stem density improved significantly (from R²=0.76 to R²=0.81), as the multispectral signal may incorporate canopy closure-related shadowing conditions at plot-level. As a result, volume prediction also improved (from R²=0.65 to R²=0.69), even though Lorey's height and basal area did not. Hence, monospecific conifer forests assessment may also benefit from ALS-imagery fusion.

Keywords:

• Sensor data fusion
• Lidar
• stem density
• Stand Density Index
• Snag detection
• Forest Health