Document Details

Title
Long-Term Sub-Boreal Mixedwood Studies
Author
Forest Investment Account (FIA)
Date
2007
Abstract
The Sub-boreal Mixedwood Studies LTRI is comprised of seven existing mixedwood stands in the sub-boreal spruce (SBS) biogeoclimatic zone with variable paper birch or trembling aspen densities, and incorporates both historic (30+ years) and new data. In 2001, the UNBC Mixedwood program took over the maintenance and management of four research sites from the Ministry of Forests and has incorporated these sites into its sub-boreal mixedwood study (FSP Y062350). Between 2000 and 2005, three additional research sites were established at Sinclair Mills, Walker Creek and on the Coalmine Forest Service Road. The four inherited sites are located at Spey Creek, Raft Creek, and two near Vama Vama Creek. The management of these complex stands will lead to enhancements in biodiversity and to the value added sector. Information on growth and yield and wood quality is lacking for mixedwood stands. Research at this LTRI addresses these two broad themes as well as economic analyses of various management scenarios. The current 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. The study site at Spey Creek is part of a large opening that includes a sizeable area of 35 year old paper birch. The dense coniferous understory is dominated by white spruce and subalpine fir with a minor component of Douglas-fir and lodgepole pine. A completely randomized design with four treatments: 1) control; 2) 1200 birch sph; 600 birch sph; and, 4) remove all birch and other broadleaf trees, was replicated 4 times. Understory conifers were thinned to 1200 sph in all treatments. Following thinning, permanent sample plots (psp?s) 0.16 ha (40 m x 40 m) were established at the centre of each main plot and all trees (paper birch and conifers) in each plot were number-tagged, and the stand was mapped. The Raft Creek study site is a large and relatively uniform area of pure paper birch that was selected for an underplanting experiment. A completely randomized design was established with five levels of canopy closure i. e. densities of paper birch (0, 300, 600, 1000 and control) and was underplanted with 4 conifer species: Douglas-fir, white spruce, subalpine fir, and lodgepole pine at 3 m spacing. Each of the treatments was replicated three times. The main treatment plots are 70 m x 70 m with a 40 m x 40 m psp in the centre (20m x 20m subplot for each conifer species). The Vama Vama Creek site was established in 1999. It is predominantly lodgepole pine and aspen with lesser amounts of spruce and subalpine fir. The experiment is a completely randomized design with six aspen densities (0, 300, 1200, 2500, 5000, and control) replicated three times. Birch within 1.5 m of conifers were cut, but aspen within 1.5 m of conifers were not cut if they were required to meet the treatment density. Treatment plots measure 50 m? 50 m with a circular 0.01 ha (radius 5.64 m) psp in an aspen patch nearest the plot centre. A second site near Vama Vama Creek, called Cozens Vama Vama, was operationally planted in 1970 and the research trial was established in 1983 to look at overstory and WPW attack. The trial has three treatments applied in 50 x 150 m plots: completely brushed, side shade, and unbrushed. The trial is replicated 3 times and all trees are stem mapped. Mixed species 5.64 m temporary sample plots were also established in 2002. The Sinclair Mills study site was established in 2000 to investigate the impact of birch overstory on white pine weevil (WPW) attack, conifer growth, and free growing specifications. The stand was logged in w ...
Report Number
FIA2007MR486
 
Title
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Annotated Bibliography
Itemized File List
Cozens Vama Vama
Raft Map
Sinclair Mills Map
Spey Creek Map
Vama Vama Map
Walker Creek Map

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