This paper investigates the application of a ground‐based laser scanning system for providing quantitative tree measurements in densely stocked plantation forests. A methodology is tested in Kielder Forest, northern England using stands of mature Sitka spruce (Picea sitchensis) and a structured mixture of Sitka spruce and lodgepole pine (Pinus contorta), standing at tree densities of 600 and 2800 stems ha−1 respectively. Three laser scans, two in the Sitka spruce and one in structured mixture, were collected using a Reigl Inc. LPM‐300VHS high‐speed laser scanner. Field measurements were recorded at the same time and included tree diameter at breast height (dbh) and tree height. These measurements were then compared with those derived from the scanner. The results demonstrate that accurate measurements of tree diameter can be derived directly from the laser scan point cloud return in instances where the sensor's view of the tree is not obstructed. Measurements of upper stem diameters, branch internodal distance and canopy dimensions can also be measured from the laser scan data. However, at the scanning spatial resolution selected, it was not possible to measure branch size. The level of detail that can be obtained from the scan data is dependent on the number and location of scans within the plot as well as the scanning resolution. Essentially, as the shadowing caused by tree density or branching frequency increases, the amount of useful information contained in the scan decreases.
[1]
M. Philip,et al.
Measuring Trees and Forests
,
1994
.
[2]
Derek D. Lichti,et al.
Ground-based Laser Scanners: Operation, systems and Applications
,
2002
.
[3]
R. Lacaze,et al.
Multi-angular optical remote sensing for assessing vegetation structure and carbon absorption
,
2003
.
[4]
Marc L. Imhoff.
A theoretical analysis of the effect of forest structure on synthetic aperture radar backscatter and the remote sensing of biomass
,
1995
.
[5]
C. Hopkinson,et al.
Assessing forest metrics with a ground-based scanning lidar
,
2004
.
[6]
C. Goulding,et al.
Estimation of timber volume in a coniferous plantation forest using Landsat TM
,
1997
.
[7]
E. Næsset.
Predicting forest stand characteristics with airborne scanning laser using a practical two-stage procedure and field data
,
2002
.
[8]
Chris Hopkinson,et al.
Assessing plot-level forest metrics with a ground-based scanning lidar
,
2004
.
[9]
Douglas A. Maguire,et al.
Modeling stem taper of three central Oregon species using nonlinear mixed effects models and autoregressive error structures
,
2003
.
[10]
G. J. Hamilton,et al.
Forest Mensuration Handbook
,
1975
.
[11]
Marc L. Imhoff,et al.
Radar backscatter and biomass saturation: ramifications for global biomass inventory
,
1995,
IEEE Transactions on Geoscience and Remote Sensing.