Forest Investment Account (FIA) - Forest Science Program
FIA Project Y073090

    Sustainable Mixedwood Management in the Sub-Boreal Spruce Zone of British Columbia
Project lead: Hawkins, Chris
Contributing Authors: Hawkins, Chris D.B.; UNBC Mixedwood Ecology and Management Program
Imprint: [BC] :, 2007
Subject: Forest Investment Account (FIA), Sustainable Forest Management, British Columbia
Series: Forest Investment Account (FIA) - Forest Science Program
Please assess this LoI under topic 1.1: Basic research on tree growth and stand development in complex stands. This study addresses all of the applicable strategic goals outlined in the Forest Science Board FIA Forest Science Program Strategic Plan 2004–2008 (FSP-SP) and also addresses key issues of the Canfor Prince George Woodlands Strategic Mixedwood Plan ( Interest in managing broadleaves and mixedwoods has grown due to a shift towards more biological/ecosystem-based management (1) as well as an increased demand for hardwood products for pulp, paper and sawlogs (2). The current 'default’ operational practice is the elimination of the non-conifer component of the stand, which among other things decreases diversity (3). Presently, there are no silviculture guidelines for managing mixed species stands in the sub-boreal spruce (SBS) biogeoclimatic zone, and when managed, they tend to be managed poorly due to a limited understanding of their dynamic processes and a lack of predictive models. There is also limited understanding of the potential impact of forest pests such as the white pine weevil (WPW), Pissodes strobi (Peck) and the effective management in mixed species stands under various silviculture treatments in the SBS. Current Free Growing Guidelines do not account for WPW management in mixed species stands. Previously, WPW attack has been shown to be diminished by the presence of deciduous overstory (4; 5), and conversely, brushing treatments that removed overstory trees lead to increased attack by WPW (6). By defining the optimum level of deciduous cover, which does not impede crop tree growth but reduces pest damage, sustainable ecological principles are utilized. Knowing how to manage complex stands will improve utilization of the site and promote biodiversity. This project examines seven existing mixedwood stands in the sub-boreal spruce (SBS) biogeoclimatic zone with variable paper birch or trembling aspen densities, incorporating both historic (30 years) and new data. These stands are located at Sinclair Mills, Bowron River, Vama Vama Creek (2 separate trials), Walker Creek, Spey Creek, and Raft Creek. The management of these complex stands is being studied in the SBS, and will lead to enhancements in biodiversity and to the value added sector. Information on growth and yield and wood quality is also lacking for mixedwood stands. This project addresses these two broad themes as well as economic analyses of various management scenarios. This study utilizes growth measurements, quality assessments, and models to determine: A) optimal threshold deciduous levels in mixed species stands, B) the influence of deciduous species in areas of White Pine Weevil (WPW) attack, C) timber quality of fast-grown spruce and birch grown at variable densities, D) growth and yield of variable density, fast-growing mixed species stands, and E) the wood quality of 30+ year old spruce developed under open-grown/high WPW attack and under aspen/low WPW attack. This study will help refine stocking standards and free growing guidelines for mixedwood stands at Regional and Provincial levels. This information will allow policy makers and natural resource managers to make informed decisions about complex stand stocking and forest health issues. The results from this project will likely lead to new provincial policies, standards and best management practices (guidelines). It will also provide cost-benefit information to forest operations with respect to stand density, wood quality and expected returns at rotation. This could be incorporated into a silviculture decision matrix, and will enhance the quality of decision making in mixed species stands.
Related projects:  FSP_Y051090FSP_Y062090
Contact: Hawkins, Chris, (250) 960-5614,


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Updated August 16, 2010 

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