Entomology

Entomology research seeks to understand and develop management strategies for account for, and reducing the impacts of insect outbreaks.

Western Spruce Budworm Impacts on Stand Growth in Dry Douglas-fir Forests, Central British Columbia - TR138

Western spruce budworm (Choristoneura freemani) is a common and destructive native defoliator found in Interior Douglas-fir (Pseudotsuga menziesii var. glauca) forests that affects tree growth and stand structure. Short-term changes in stem density and periodic annual increment (basal area and volume) were compared among treatments for a period overlapping an outbreak of western spruce budworm (WSB) (2002–2012) and a period of WSB inactivity (2013–2017). In this pilot study, there were two blocks with each containing three treatments. The treatments included a no-harvest Control, a Logged treatment with a target basal area of 15 m²/ha, and a Logged-thinned treatment that included pre-commercial thinning post harvest. During the active WSB period, there was stem loss and little increase in volume in the Control and Logged treatments. There was minimal stem loss and little increase in volume in the Logged-thinned treatment. In the inactive WSB period, volume growth improved in the Control and Logged treatments and in one Logged-thinned treatment unit, while in the other Loggedthinned treatment unit growth did not improve. Among treatments in both time periods, the Logged-thinned treatment volume growth remained positive while the Control and Logged treatments were either negative or positive. 

A Framework for Documenting the Effects of the Mountain Pine Beetle Outbreak in Sub-Boreal Forests of Northern British Columbia (E.P. 1369): Establishment Report  - TR46

This report outlines the objectives, study design, methods of data collection, and other details relevant to the establishment of Experimental Project (EP) 1369: A Framework for Documenting the Effects of the Mountain Pine Beetle in Sub-boreal Forests of Northern British Columbia. In 1995 through 1997, 48 plots were established in mature pine leading stands affected by mountain pine beetle (MPB) (38 plots) and MPB followed by wildfire (10 plots). All plots will remain unharvested, and are designed to examine ecological changes subsequent to these disturbances. The information from these plots will inform science on what ecological changes result from these disturbances in the sub-boreal forest landscape, and will provide critical information (such as growth rate of live understorey) to land managers.

Mountain Pine Beetle, Forest Practices, and Watershed Management  - EN88

As the mountain pine beetle (mpb) infestation expands, changes to British Columbia’s lodgepole pine forests will affect hillslope hydrology and streamflow in many watersheds (Figure 1). Stream channels, water quality, aquatic habitat, public infrastructure, and private property may also be affected. Recent literature reviews have described the hydrologic effects of logging and wildfire and then interpreted the relevance of this information to mpb-related stand mortality (e.g., Stednick and Troendle 2004; Hélie et al. 2005; Uunila et al. 2006; Redding and Pike 2007). This article summarizes the key hydrologic changes expected and highlights the initial results of new research under way throughout the B.C. Interior to quantify changes in stand scale hydrologic processes and the potential watershed-scale effects of mpb-related stand mortality and salvage logging. General forest planning recommendations and other sources of information are also provided.

Development of a Research Strategy for Mountain Pine Beetle Issues Associated with Forest Stewardship Division Functions - TR34

The current mountain pine beetle (MPB; Dendroctonus ponderosae Hopkins) epidemic is the largest known outbreak in British Columbia’s history. This outbreak has resulted in serious implications for ecosystems, communities, and local economies, and many issues have arisen that require research for an adequate resolution. The Chief Forester of British Columbia therefore requested the initiation of a research strategy as a step in resolving these important issues. The development process for the Mountain Pine Beetle Stewardship Research Strategy involved four steps: analyzing the forest stewardship needs, analyzing the research knowledge gaps, prioritizing the knowledge gaps, and writing the MPB stewardship research strategy. The needs analysis involved the identification of stewardship issues by both client groups and researchers; researchers also identified research projects that are planned, under way, or completed. During the gap analysis phase, this information was used to determine the gaps in our knowledge. Gap priorities were set by ranking each knowledge gap on a scale of 0–5 for urgency and importance. These ranks were then converted into a priority of low, medium, or high. Writing the strategy required consolidating the information into a concise and coherent document. In addition to identifying and prioritizing knowledge gaps, the strategy also recommends the formation of the Research Issues Co-ordinating Committee to oversee the implementation of the strategy

Interactions Between Fertilization and White Pine Weevil (Pissodes Strobi) Attack in Young Interior Spruce Plantations - EN75

White pine weevil (Pissodes strobi (Peck)) damage was surveyed at three interior spruce (Picea glauca × engelmannii) fertilization research installations to document the effects of different fertilizer regimes and frequencies on weevil attack incidence. Weevil attack rates increased with fertilization intensity at a site with well-established and evenly distributed weevil populations. From 24% (unfertilized) to 54% (repeatedly fertilized) of trees were attacked at least once over the 6-year study period. The longer, thicker leaders of fertilized trees likely increased the resources available for weevil feeding and oviposition. A dilution of the leader’s resin canal defence system may have also contributed to higher levels of weevil attack in repeatedly fertilized trees. However, despite the more frequent weevil damage to fertilized trees, the height losses caused by weevil attack were less than the height gains due to fertilization. The other two sites had smaller, or less evenly distributed, weevil populations, reflected in much lower weevil attack rates and fertilizerstimulated attack impacts. Results indicate that the beneficial effects of fertilization on the growth of young interior spruce plantations likely outweigh the negative effects associated with increased incidence and severity of leader damage from the white pine weevil.