UBC Theses and Dissertations
Do visual quality objectives necessarily constrain timber harvest levels? : subtitle exploring the potential of partial cutting Picard, Paul
The present thesis is an attempt to identify possible win:win solutions to the apparent and widely reported conflict between aesthetics and the practice of timber harvesting in British Columbia (BC). The approach used is to review the literature on silvicultural systems, Visual Resource Management (VRM) as practiced in BC, public perceptions of various harvesting practices, the relationship between aesthetics and timber harvest levels, and on long term timber supply implications of proposed solutions in order to provide for a more complete picture. A series of short-term modelling exercises has been undertaken to assess the potential of using certain visually effective partial cutting techniques (termed dispersed retention cuttings here) as a possible solution to the conflict. This includes a description and comparison of the results obtained with similar independent modelling exercises. Key findings from the reviews and modelling analysis include the following: 1) Confusion still exists regarding "partial cutting". The term "dispersed retention cutting" is put forward in this thesis to reduce this confusion when discussing more visually acceptable forms of partial cutting. 2) There is a failure to consider the broader landscape-level context in BC, which has significant implications for the management of visual resources. 3) People prefer dispersed retention cutting to clearcutting for a given level of timber removal and some kinds of dispersed retention cutting can virtually eliminate VQOs as a constraint both in the short and long term. The perception that VQOs are a major constraint on timber harvesting appears to be an artefact of the reliance on clearcutting. 4) More research is needed on the feasibility of dispersed retention cutting techniques in different forest types. There is a difference of opinion among practitioners as to the extent to which dispersed retention cutting can be realistically undertaken. 5) Further analysis of the sensitivity of timber supply calculations to the harvesting practices (clearcutting or others) used in visually sensitive areas is needed. 6) More research is needed to find and validate key visual quality thresholds (e.g. at which level of removal is a dispersed retention cut perceived as a clearcut by the public?) and to develop landscape models that can handle dispersed retention cutting techniques over time and over large areas. Key Words: visual resource management, visual quality, public perceptions, partial cutting, forest, landscape, timber supply, timber availability, visual quality intensity index.
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