86 resources found

This document investigates how leaving different amounts of mature tree cover during timber harvests affects the development of newly replanted Douglas-fir in coastal British Columbia. By comparing various levels of dispersed retention, ranging from clearcuts to 30% forest cover, the researchers tracked the height, diameter, and survival rates of young trees over a 5-6 year period. The results demonstrated that while most lower retention levels did not hinder early growth, a statistically significant reduction in stem diameter occurred at the 30% retention level, likely due to decreased light availability. This document suggests that while higher levels of forest structure may slightly slow development, young Douglas-fir can remain resilient and viable under moderate levels of overstory shade.

This document details the long-term findings of the Salal Cedar Hemlock Integrated Research Program, which investigated why certain conifer plantations in coastal British Columbia experience stunted growth. The study focuses on nutrient deficiencies caused by the competitive reinvasion of salal, an aggressive shrub that thrives after clearcutting and limits the availability of nitrogen and phosphorus to young trees. Through various silvicultural trials, the authors demonstrate that combined nitrogen and phosphorus fertilization significantly boosts the productivity of Sitka spruce and western hemlock, while western redcedar shows a stronger response to the manual or chemical removal of salal. Additionally, the research explored alternative strategies such as using lodgepole pine as a nurse species and applying organic fertilizers like biosolids and fish silage, which offered growth benefits comparable to inorganic options.

This field guide provides a comprehensive framework for addressing regeneration failure on coastal old-growth cedar-hemlock sites in British Columbia, where the aggressive expansion of salal shrubs creates severe nutrient deficiencies. The document identifies the primary obstacle as a lack of available nitrogen and phosphorus caused by the unique chemistry of cedar litter and the interference of salal tannins in soil processes. To overcome this, the guide advocates for a silvicultural strategy focused on achieving rapid crown closure through a combination of clearcutting, mechanical site preparation or burning, and the use of high-quality planting stock. The author also emphasizes that targeted fertilization with both inorganic and organic materials is essential to sustain tree growth and eventually shade out competing vegetation. This guide serves as a practical manual for foresters to transform stagnant, nutrient-poor sites into productive, closed-canopy coniferous stands.

This document details an investigation into the manual control of red alder to promote the growth of planted Douglas-fir and grand fir seedlings. By testing five different cutting schedules, researchers sought to determine if the timing of brush removal influenced how effectively it prevented the alder from resprouting and competing for resources. The study concludes that performing this work during the late growing season maximizes the death of the alder stumps while minimizing new growth, though environmental factors like moisture stress significantly impacted the overall health of both the deciduous and coniferous trees.

This FRDA Report #146 evaluates the effectiveness of a brown and burn forest management strategy used to transform brush-heavy land in coastal British Columbia into productive conifer plantations. The study specifically compares the environmental impacts and seedling growth outcomes of applying glyphosate herbicide either one year prior to or in the same year as a prescribed fire. By meticulously measuring nutrient status, soil properties, and vegetation regrowth, the author concludes that both methods are feasible for site rehabilitation and the earlier herbicide application generally led to greater fuel consumption and better suppression of competing plants. This document can assist with optimizing site preparation techniques to ensure the successful establishment of Douglas-fir seedlings in specific ecological subzones.

This document evaluates a decade of data from the Montane Alternative Silvicultural Systems project to determine how different timber harvesting methods affect the regeneration of non-dominant conifer species in British Columbia. By comparing various environments ranging from open clearcuts to high-density shelterwood retention, the study highlights how a species' unique ecological attributes and shade tolerance dictate its survival and growth in harsh, high-elevation climates. The findings suggest that yellow-cedar shows promise for reliable performance, and that low-elevation species like Douglas-fir and western redcedar struggle with poor survival or slow growth due to snowpack and frost. This document emphasized that successful reforestation requires matching specific tree types to the precise light and climatic conditions created by different harvesting strategies.

This document investigates the six-year growth and survival of noble fir in coastal British Columbia, a region where the species does not occur naturally. By testing 23 different seed sources across 12 diverse locations, the author examines how various environmental conditions and genetic origins influence the tree's performance. The findings indicate that while the species is highly productive and resilient in maritime climates, it remains vulnerable to frost in more continental settings. This document aims to identify ideal planting sites and superior seed sources to guide the successful introduction of noble fir for regional reforestation.

This technical report examines how different prescribed burning intensities influence coastal ecosystems in British Columbia, specifically focusing on fuel consumption and soil impacts. By comparing low-severity spring burns with high-severity fall burns, the study demonstrates that timing and weather significantly dictate how much woody debris and forest floor organic matter are destroyed. The researchers found that spring burns effectively clear small debris with minimal soil damage, but intense fall burns lead to substantial forest floor consumption and increased mineral soil exposure, which may threaten long-term site productivity.

This decision aid is designed to assist forest managers in revitalizing conifer growth within the Coastal Western Hemlock biogeoclimatic zone. The primary challenge addressed is the nutrient deficiency caused by aggressive salal competition, which stunts the development of valuable tree species like western redcedar and western hemlock following a harvest. To combat this, the document provides a structured framework for silvicultural interventions, recommending specific methods of site preparation, herbicidal control, and strategic fertilization to ensure seedlings reach a self-sustaining state of crown closure. Beyond industrial productivity, the document also highlights the cultural and economic importance of these plant species, acknowledging their vital role in First Nations traditions and the emerging market for non-timber forest products.

This technical report evaluates a 14-year study on how clump thinning of bigleaf maple affects the development of both the maples and intermixed planted conifers in British Columbia. Because bigleaf maples regenerate via vigorous stump sprouting, they often overtop and outcompete young conifers, leading researchers to test whether reducing maple density could improve conifer survival and growth. The results revealed that manual thinning was largely ineffective for timber management, as the maple's rapid canopy closure and aggressive re-sprouting meant that the treatment provided no significant long-term growth advantage to the underlying conifers. Instead, the study suggests that bigleaf maple thrives under a coppice-based management system, where sprout growth is dictated more by internal clump dynamics than by the overall density of the stand. The authors conclude that while thinning does not benefit conifers, these mixedwood sites remain highly productive and may be better suited for short-rotation hardwood fiber production.

This document examines the growth and yield dynamics of a 14 year-old mixed-species plantation featuring Western redcedar and red alder in British Columbia. By comparing various planting ratios, the authors explore how complementary resource use affects tree development compared to single-species monocultures. The study reveals that while individual cedar growth improved in a balanced 50:50 mixture, the total stand productivity did not exceed that of pure stands, suggesting that mixtures offer benefits in biodiversity and wood quality rather than overall biomass volume. This document serves as a guide for forest managers to consider the ecological advantages of mixedwoods and provides a density threshold for maintaining conifer health when growing alongside alder.

This document examines a twenty-year study in British Columbia regarding the complex relationship between red alder and two conifer species, Douglas-fir and western redcedar. While alder is often removed by foresters because it competes for light and space, it also provides essential benefits by naturally fertilizing the soil with nitrogen. The findings suggest that maintaining a specific density of 100 to 200 alder trees per hectare can actually support conifer growth, particularly on nutrient-poor sites. The authors conclude that traditional forestry assessment methods may be inadequate, recommending a larger plot radius to more accurately measure how these different tree species interact and compete over time.

This document examines the ecological role and management of bigleaf maple within coastal mixedwood forests. While the species promotes nutrient cycling and biodiversity, its rapid regrowth after harvesting creates dense canopies that can suppress understorey conifers by blocking nearly all sunlight and causing physical damage. To address this, researchers established two experiments near Port Alberni to determine how different coppice densities and thinning intensities affect available light levels and tree performance. The study seeks to provide a scientific framework for balancing the commercial and environmental value of bigleaf maple with the successful growth of evergreen species like Douglas-fir.

This document examines how pre-commercial thinning influences the development of coastal Douglas-fir plantations in British Columbia. By evaluating seventeen years of data from various thinning regimes, the study demonstrates that reducing stand density significantly enhances the merchantable volume and diameter of individual trees. The author specifically recommends gradual thinning to a density of fewer than 1, 000 stems per hectare before the stand reaches thirty years of age to optimize sawlog production. This document serves as a practical guide for foresters, providing empirical evidence and growth simulation data to support more effective timber management strategies on medium-quality sites.

This technical report evaluates the effectiveness of selection harvesting as an alternative to clearcutting within the old-growth temperate rainforests of Vancouver Island. By comparing single-tree and group selection methods, the study examines how these systems maintain an uneven-aged stand structure while meeting reforestation requirements on steep, ecologically sensitive terrain. The research highlights significant operational challenges, noting that safety regulations and the complexities of helicopter yarding often require foresters to adapt their initial harvesting prescriptions. This document concludes that while natural regeneration is abundant, the slow growth rates in shaded environments may require adjusted timelines for achieving free-growing status and long-term forest health.

This document evaluates the long-term effectiveness of dispersed tree retention as an alternative to clearcutting in the coast-interior transition zone of British Columbia. By monitoring a Douglas-fir forest near Boston Bar for fifteen years, the study examines how various levels of overstorey shading influence natural regeneration success, stand structure, and biological legacies. The data reveals that while residual trees enhance the micro-climate for new growth, they face significant mortality from windthrow, Douglas-fir bark beetle, and wildfire, leading to a substantial decline in living density over time. This document suggests that while dispersed retention provides valuable biodiversity attributes like snags and woody debris, an aggregated retention pattern might offer greater stability and protection against environmental stressors.

This document outlines a comprehensive long-term forestry study located near Campbell River, British Columbia, designed to evaluate alternatives to clearcut harvesting in mature second-growth forests. The research compares seven distinct silvicultural systems, ranging from traditional clearcutting to more complex methods like aggregated retention and group selection, to determine their impact on forest resilience and biodiversity. By tracking variables such as timber productivity, harvesting costs, and ecological regeneration, the study aims to identify management strategies that balance economic demands with the preservation of ecosystem services in the face of climate change. Detailed assessments of soil disturbance, vegetation shifts, and tree growth serve as a vital demonstration and experimental resource for foresters and scientists seeking to maintain healthy, multi-use forest landscapes.

This webinar outlines the strategic framework for wildfire risk reduction in British Columbia, emphasizing the transition from traditional fire suppression to proactive fuel management. It explores how effective mitigation requires a risk-based approach, where practitioners analyze the likelihood and consequences of fire to prioritize treatments within the wildland-urban interface. Central to the webinar is the use of science-based fire behavior targets, such as maintaining specific critical surface intensities and increasing crown base height to prevent ground fires from climbing into the canopy. The webinar highlights that while mechanical thinning is vital, the integration of prescribed fire and FireSmart principles is essential for maintaining these fuel breaks and ensuring long-term community resiliency.

This LMH #64 handbook outlines a strategic framework for compatible management, an approach that allows the forestry industry to simultaneously harvest timber and high-value pine mushrooms. Because these mushrooms share a symbiotic relationship with the roots of living, mature trees, traditional clear-cutting effectively eliminates their production for decades. To prevent this economic and ecological loss, the authors propose a four-step cycle involving habitat mapping, identifying overlap zones, implementing alternative silvicultural systems and long-term monitoring. By focusing timber operations on highly productive wood sites while preserving the well-drained, nutrient-poor soils where mushrooms thrive, land managers can achieve a winwin situation that supports both local biodiversity and diverse revenue streams. This handbook emphasizes that maintaining a landscape-level mosaic of varying forest ages is essential for the sustained commercial viability of non-timber forest products.

This PhD thesis investigates the influence of nitrogen-fixing alders on the productivity and nutrient dynamics of Douglas-fir plantations in the Pacific Northwest. Through seven case studies, the author compares the effects of red alder and Sitka alder, demonstrating that these species significantly enhance ecosystem net primary production and soil fertility on nutrient-poor sites. A critical finding is that the benefits of alder are site-dependent; while they accelerate tree growth on infertile sites, they can actually suppress conifer development and reduce biomass on fertile sites due to intense competition. This research positions Sitka alder as a low-competition alternative to red alder, suggesting both species are valuable biological tools for sustainable forest management on nitrogen-deficient land.