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There is an increasing interest in mixed conifer-broadleaf stands as a way to increase the diversity and productivity of managed forests. This study examined the impacts of varying densities of planted broadleaf trees on conifer performance, total stand productivity, and understory plant cover 20 years after stand establishment. The study took place in the Malcolm Knapp Research Forest in Maple Ridge, British Columbia. It used a randomized complete block design to compare treatments containing low, moderate, or high broadleaf densities added to a constant conifer density. Each block contained a conifer-only plot as a control. Conifers were composed of equal amounts of western hemlock, western redcedar, and Douglas-fir. Broadleaves were composed of either red alder or paper birch. We found that conifer volume was significantly lower in most broadleaf treatments relative to the control, due to lower hemlock and redcedar volumes. Douglas-fir, on the other hand, had a higher volume—albeit not significant—in the broadleaf treatments. There were no significant differences in total stand volume between any of the treatments and the control. Shrub cover was significantly higher in the low and high alder treatments relative to the control, but there were no differences in shrub cover between birch treatments and the control. The results suggest that low alder density provides a good balance of conifer yield and understory development. [ABSTRACT FROM AUTHOR]

In northern British Columbia and southern Yukon woodland, caribou forage extensively on terrestrial lichens, predominately mat-forming Cladina species in late-successional pine-lichen woodlands. Many of these stands are now reaching a point in their development where lichen abundance declines as feather-moss mats increase. We evaluated the response of forest floor plant communities in pine-lichen woodlands from the southern Yukon Lewes Marsh partial-cutting trial 8 years after harvesting. Photoplot results documented a major decline (>60% ± 5.6% SE) in the mean surface area of existing large clumps of C. mitis in control (unharvested) treatments, whereas the mean surface area of large C. mitis clumps declined by 28% (±15% SE) in the one-third basal-area removal and showed an increase of 13.5% (±25% SE) in the two-thirds basal-area removal. Line intercept transects documented no changes in overall stand-level lichen abundance between pre-harvest (2012) and post-harvest (2021) measurements, while feather-moss mats and dwarf shrubs showed declines and increases, respectively, in partial-cutting harvest plots. Stand thinning may provide a bridging strategy to extend the period of forage lichen availability in late-seral pine-lichen woodlands, an important consideration in landscapes where increasing severity and frequency of fires are changing the seral-state distribution of caribou habitat. [ABSTRACT FROM AUTHOR]

We assessed the impacts of three approaches to thinning from below with varying spatial patterns on several stand and individual tree variables for interior Douglas-fir (Pseudotsuga menziesii var. glauca (Beissn.) Franco), interior spruce (Picea glauca (Moench) Voss × Picea engelmannii Engelm.), and lodgepole pine (Pinus contorta Dougl. Ex Loud. var. latifolia Englem.) in central British Columbia, Canada. The three thinning treatments were two experimental "clumped" treatments (3 m Clumped and 5 m Clumped) and the Standard (more uniform spacing) thinning treatment that was employed operationally at that time. We used long-term data from 24 plots measured five times over 21 years. Thinning increased stand basal area increment, with the plots that received the 5 m Clumped treatment having significantly higher periodic annual relative basal area increment than the unthinned Control plots. The responses for the two clumped treatments were not any lower than the Standard. The 3 m Clumped treatment was best if one is concerned about fast recovery of the growing space; however, the 5 m Clumped spacing treatment may be preferable if higher individual tree vigour is needed for resistance and resilience to fire, insects, and disease. [ABSTRACT FROM AUTHOR]

As wildfires are increasingly causing negative impacts to communities and their livelihoods, many communities are demanding more proactive and locally driven approaches to address wildfire risk. This marks a shift away from centralized governance models where decision-making is concentrated in government agencies that prioritize reactive wildfire suppression. In British Columbia (BC), Canada, Community Forests—a long-term, area-based tenure granted to Indigenous and/or local communities—are emerging as local leaders facilitating proactive wildfire management. To explore the factors that are enabling local governance approaches to managing wildfire risk, we conducted semi-structured interviews with 26 Community Forest managers across BC. Managers highlighted financial and social capacity, especially trust and relationships with both community members and government agencies, as crucial factors influencing their ability to undertake proactive management. These factors enable Community Forests to address wildfire risk not only within their own tenure area, but also at household, community, and landscape scales, while balancing diverse community values, objectives for forest management, and legal and policy obligations. Despite ongoing challenges, Community Forests emphasized the importance of scaling up their efforts to address wildfire risk and are a critical form of local wildfire governance that can help advance proactive wildfire management across BC. [ABSTRACT FROM AUTHOR]

Forestry is becoming more complex as a result of diverging societal demands. Indigenous Peoples' reconciliation and the challenges of climate change call for research that embraces transdisciplinarity, reciprocity, and problem-focused learning at the landscape scale. Both globally and in Canada, forestry and forest research are struggling to keep pace with this growing complexity. Place-based collaborative research and learning initiatives, described here as "learning landscapes," offer an under-explored approach to meeting diversifying goals for forest landscapes. We describe recent progress in Quesnel, British Columbia, where researchers and local institutions are engaging to strengthen resilience and innovation in the forest sector. We first define the concept of learning landscape in the context of transdisciplinary sustainability science, and then illustrate this approach using the case study of Quesnel. We describe a process of systems diagnosis, including asset mapping and analysis of potential forestry pathways through a "best bets" framework. We propose a Theory of Change as a way forward, outlining opportunities for government, industry, and communities in developing regional capacity for integrated management and high-value forest products. We reflect on the contributions of learning landscapes to knowledge generation, experiential learning, and institutional development, and discuss implications for steering decision-making in locally driven sustainability transitions. [ABSTRACT FROM AUTHOR]

Seismic lines are linear features created by the oil and gas industry for energy exploration. Though individually narrow, collectively seismic lines are a pervasive management challenge, resulting in changes to biogeochemical cycles, plant and animal abundance and behaviour, predator–prey relationships, and forest successional trajectories. These impacts arise from historical construction methods that used bulldozers to remove vegetation and substrate leaving lines as persistent openings in a state of arrested succession. In the mid-1990s, "low-impact seismic" (LIS) line construction began, using mulchers to remove vegetation aboveground to minimize impacts and hasten reforestation. Here, we evaluated the effectiveness of LIS in retention, recruitment, and growth of seedlings in forested peatlands in northeast British Columbia. Retained and recruited trees on LIS lines were found at 69% and 64% of sites, had mean densities of 3400 and 6000 stems/ha, and mean heights of 42 and 11 cm, respectively. These LIS lines appeared to recover along expected trajectories toward tree cover, thereby mitigating challenges typical of older seismic exploration. Our results suggest it is feasible to further fast-forward line recovery by ensuring mulcher drums are kept as high as possible to increase the number and height of trees through the mulching process. [ABSTRACT FROM AUTHOR]

As forest managers increasingly seek to implement partial-harvest silviculture systems in complex forests, more data are required on the potential development of the residual stand following treatment. In this study, we present 25-year data from a long-term silvicultural study of tree- and stand-level responses to differing levels of basal area following partial harvest in a complex spruce–fir forest in central British Columbia, Canada. Reducing stand basal area elicited stronger basal area increment response in fir than spruce; however, spruce productivity was overall higher than fir across all treatments. Smaller trees increased their size proportionally more than larger trees, and thinning resulted in increased recruitment of smaller trees into larger diameter classes. At the stand-level, basal area reductions to well below 20 m2/ha resulted in higher volume and basal area growth over the length of this study, and suggest that optimum stand-level growth may be achieved at lower basal areas than suggested in prior literature. We also found a positive relationship between stand-level residual basal area and mortality. In central British Columbia, stand structure, species composition, and growth rates in complex spruce–fir forests can be maintained through partial-harvest silviculture treatments. [ABSTRACT FROM AUTHOR]

Copyright of Canadian Journal of Forest Research is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Forest Research is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Forest Research is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)