Forest Investment Account (FIA) - Forest Science Program
FIA Project Y091079

    An Evaluation of Brushing and Spacing Treatments Growing Space Management in Boreal Forest Mixedwoods
Project lead: Harper, George (BC Ministry of Forests and Range)
Subject: Forest Investment Account (FIA), British Columbia
Series: Forest Investment Account (FIA) - Forest Science Program
This project addresses the need for information relating to developing management practices for deliberately growing spruce-aspen mixtures. Although considerable information on chemical and manual brushing to control deciduous trees and shrubs exists, there is a need to test and demonstrate cost-effective, environmentally sound, and socially acceptable alternatives to broadcast herbicide applications.
Some key questions that require addressing include:
How do brushing treatments influence competition dynamics, relationships between conifer growth and competition, and the growth of aspen?
What are the long-term consequences of these selected treatment options?
Can manual and chemical brushing treatments be used to promote the establishment of boreal mixedwood stands?

In order to address these questions, Experimental Project 1192.01 was established in the Fort Nelson Forest District during 2001 to examine six operational brushing alternatives for boreal mixedwood forests (Harper and Biring 2002 see attached document file). This experiment explores complete removal of aspen, aspen thinning and small-radius treatments involving both circular brushing and spot applications of herbicides as tools for management of aspen densities and for promoting spruce growth within a mixedwood management prescription.

The research trial contains 6 treatments replicated 3 times (18 plots of 0.25 ha size) in a completely randomized design. The large plots will provide both short-and long-term information needs supporting the continuing evolution of boreal mixedwood management. The trial will also provide needed data to support existing stand level models such as TASS (Mitchell 1975) and MGM (Titus 2003). Past light measurements and tree data from this trial have already been used in recent TASS aspen and boreal mixedwood calibration efforts. Extension Note 64 (Harper and Kabzems 2003) has documented the trial establishment and early treatment observations. Funding is requested to support the 2008 re-measurement and publication of 2001 2008 post-treatment response results. Funds are also needed to develop the demonstration potential of the site.

This project will help to build specific, measurable criteria for assessing if regeneration performance is consistent with desired future forest condition. Current regeneration assessments have not clearly linked to growth and future yield of mixed species stands.

The continued assessments of plant communities over time in different treatment regimes will help to build credible, quantitative assessment of early stand succession trajectories in boreal mixedwoods.
Related projects:  FSP_Y102079
Contact: Harper, George, (250) 387-8904,


Executive summary (24Kb)

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Updated August 16, 2010 

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