Download the full-sized PDF of Identifying and Assessing the Yield Implications of Forest Canopy Gaps in Forest Management Using Full Feature LiDARDownload the full-sized PDF



Permanent link (DOI):


Export to: EndNote  |  Zotero  |  Mendeley


This file is in the following communities:

Graduate Studies and Research, Faculty of


This file is in the following collections:

Theses and Dissertations

Identifying and Assessing the Yield Implications of Forest Canopy Gaps in Forest Management Using Full Feature LiDAR Open Access


Other title
Wet Areas Mapping
Forest Gap Dynamics
Type of item
Degree grantor
University of Alberta
Author or creator
Jensen, Daniel E
Supervisor and department
Comeau, Phil (Renewable Resources)
Bokalo, Mike (Renewable Resources)
Examining committee member and department
Nielsen, Scott (Renewable Resources)
Armstrong, Glen (Renewable Resources)
White, Barry (Alberta Environment and Sustainable Resource Development)
Department of Renewable Resources
Forest Biology and Management
Date accepted
Graduation date
Master of Science
Degree level
Gaps in the forest canopy are common in boreal aspen, spruce and mixedwood stands and can negatively affect forest volume. Data from four Alberta Vegetation Inventory (AVI) polygons, two aspen (Populus tremuloides) and two white spruce (Picea glauca), were analysed to determine how forest volume is affected by the presence of forest canopy gaps and to determine if this approach could be used to reconcile stand volumes estimated by growth models with volumes obtained from ground samples. LiDAR point clouds were processed to create canopy height models (CHMs) for each polygon to differentiate canopy cover from canopy gaps. Strong curvilinear relationships were found between LiDAR gap area and expanded gap area measured in the stands (R2 > 0.90). Based on the estimated expanded gap areas, the potential volume loss due to gaps in each polygon was assessed. Potential polygon volume was estimated by determining the average tree occupancy area for canopy trees within fully stocked areas of each polygon and then estimating the “missing” volume based on the number of trees required to fill the gaps. By comparing the estimates of volume lost to gaps to the potential polygon volume when the gaps were filled, it was shown that gaps affect volume by upwards of 18%. However, the effect of gaps on volume was variable between polygons. Lastly, the CHMs were combined with wet areas maps depicting depth to water index. Estimates of the effects of hydrology on gap size and frequency were calculated with results showing that gaps are larger and more frequent in poorly drained soils than they are in well drained soils.
Permission is hereby granted to the University of Alberta Libraries to reproduce single copies of this thesis and to lend or sell such copies for private, scholarly or scientific research purposes only. Where the thesis is converted to, or otherwise made available in digital form, the University of Alberta will advise potential users of the thesis of these terms. The author reserves all other publication and other rights in association with the copyright in the thesis and, except as herein before provided, neither the thesis nor any substantial portion thereof may be printed or otherwise reproduced in any material form whatsoever without the author's prior written permission.
Citation for previous publication

File Details

Date Uploaded
Date Modified
Audit Status
Audits have not yet been run on this file.
File format: pdf (PDF/A)
Mime type: application/pdf
File size: 2639183
Last modified: 2015:10:21 23:52:09-06:00
Filename: Jensen_Daniel_E_201501_MSc.pdf
Original checksum: c94ce7341fc077722dd91fb73987dd23
Activity of users you follow
User Activity Date