Holmgren, Johan
- Department of Forest Resource Management, Swedish University of Agricultural Sciences
Conference paper2008Peer reviewed
Holmgren, Johan; Johansson, Fredrik; Olofsson, Kenneth; Olsson, Håkan; Glimskär, Anders Ove
Vegetation mapping for environmental monitoring is today conducted by manual photo-interpretation combined with field surveys. This study is the first attempt in Sweden to investigate the potential of using Airborne Laser Scanning (ALS) for the estimation of crown coverage of tree crowns and shrubs. Thirty field plots were randomly allocated within a 1×1 km2 area in southern Sweden. All plants with any part inside the 10 m radius and with a height greater than 0.3 m were measured. The field data were used to derive crown coverage for each plot. Proportions of laser returns within height intervals were derived from ALS data and used as explanatory variables in simple linear regression models for estimation of crown coverage of trees and shrubs. For estimation of tree crown coverage (> 3.0 m height) the root-mean-square-error (RMSE) was 4.9%. For estimation of total (trees and scrubs) crown coverage (> 0.3 m height) the RMSE was 6.3%. These RMSE values were achieved despite a mixture of tree species on the field plots. However, the analysis was not sufficient for high accuracy estimations of the amount crown coverage from shrubs (0.3-3.0 m height interval) below a tree canopy
Silvilaser 2008
Forest Science
https://res.slu.se/id/publ/19408