67 resources found

This document details a research project in the Cariboo Region of British Columbia focused on revising free-growing guidelines to better account for the interactions between young conifer plantations and broadleaf trees, particularly trembling aspen. The central theme is understanding the competitive relationships between aspen and various conifer species across different biogeoclimatic zones. Through long-term experimental studies and field verification, the researchers gathered data on tree growth, health, and density to propose scientifically supported adjustments to the regulations that determine when a reforested area is considered successfully established. The goal of this study was to create more ecologically informed and practically applicable guidelines that recognize the potential benefits of broadleaf presence while ensuring successful conifer regeneration for timber production.

This document details an analysis using the PrognosisBC model to evaluate various partial-cutting silvicultural options for long-term forest management compared to clearcutting. The authors explore how different harvesting methods in a specific forest type could meet sustainability targets, encompassing biodiversity, visual quality, old-growth recruitment, and timber production over a 100-year rotation. By modeling several scenarios and comparing their outputs, the study aims to familiarize readers with the PrognosisBC tool and demonstrate its utility in assessing trade-offs and informing complex forest management decisions, while also acknowledging the model's limitations and the crucial role of professional judgment.

This document details the establishment and early findings of the Roberts Creek Study Forest. The RCSF was created to demonstrate and evaluate various alternatives to clearcutting in mature Douglas-fir dominated forests on the Sunshine Coast. By implementing different silvicultural systems, such as dispersed retention and extended rotation, the study aims to assess their impacts on aspects like harvesting, windthrow, and the regeneration of conifer species like Douglas-fir and western redcedar, while also considering ecological, social, and economic objectives in forest management. The report outlines the study area, methodologies used for different treatments, and presents initial results regarding post-harvest stand structure, soil disturbance, windthrow patterns, seedfall, and both natural and planted regeneration.

This FREP Report #8 details a timber-focused evaluation of partially harvested forest areas within a specific management unit. Its core purpose was to determine if the resulting stand conditions aligned with the government's objectives for timber, as outlined in the Forest and Range Practices Act. The evaluation employed both routine and intensive assessment methods to analyze various indicators, such as stocking levels, wood volume, and tree quality, and even used growth simulation to predict future stand development under different management scenarios. The report aimed to assess the effectiveness of partial harvesting practices in meeting timber objectives and to provide recommendations for improvement in practices, evaluation methods, and related policies.

This FRDA Report #196 is a synthesis of project results investigating the effects of fertilization and thinning on a Douglas-fir ecosystem at Shawnigan Lake, British Columbia. The research reports on a long-term, multidisciplinary study examining how these forest management techniques influence tree growth, physiology, and ecosystem processes. Key themes include the long-term impact on growth and yield, the mechanistic response of the trees to nitrogen, and the fate of nitrogen fertilizers within the soil and water systems. This document provides a comprehensive overview intended to inform better forest management practices by synthesizing decades of experimental data.

This technical report introduces a drought risk assessment tool designed to help forest managers in British Columbia navigate the challenges of a warming climate. By using a stand-level water-balance approach, the researchers calculated the ratio of water availability to evaporative demand to establish drought tolerance thresholds for ten common tree species. The study concludes that many species face significant threats of stress and mortality on drier sites, whereas moist, water-receiving areas may serve as critical climate refugia for conservation. This document provides a practical framework for applying this data to silvicultural decisions, such as selecting resilient species for reforestation and identifying areas at higher risk for wildfires or invasive species.

This technical report evaluates how varying levels of aspen retention influence the development of mixed-species forest stands in British Columbia, specifically focusing on the growth of lodgepole pine and the emergence of aspen suckers. By comparing different thinning intensities against an untreated control, the researchers sought to identify thresholds for competition that allow for optimal timber production while maintaining the ecological benefits of broadleaf trees. The findings indicate that while pine vigour improved when fewer than 1000 aspen stems per hectare were kept, significant differences in tree height and diameter were not yet apparent four years after treatment. Additionally, the study confirms that complete aspen removal triggers the highest density of new suckering, whereas leaving residual trees helps suppress this regrowth. This document serves as a guide for silviculturists to refine free-growing standards and develop cost-effective management strategies for complex sub-boreal ecosystems.

This extension note examines the evolving management of boreal and sub-boreal mixedwood forests in British Columbia, specifically focusing on the integration of broadleaf trees like aspen and birch into traditionally conifer-dominant landscapes. While historical policies treated broadleaves as an impediment to timber production, this document highlights their essential contributions to ecological resilience, biodiversity, and soil health, alongside their potential for industrial diversification. Through a comprehensive literature review, the authors identify a critical trade-off in growth and yield, noting that while broadleaf competition can reduce individual conifer size, mixed stands often achieve a higher total wood volume than pure stands. This document serves as a call for enhanced research and policy reform to bridge significant knowledge gaps, seeking to balance economic timber supply with the diverse long-term benefits of a natural forest mixture.

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 investigates how trembling aspen competition impacts the growth and survival of lodgepole pine within the Southern Interior Forest Region of British Columbia. By monitoring several forest sites over a seven-year period, researchers determined that tall aspen density is the most effective metric for predicting declines in pine diameter and overall vigor, likely due to competition for available light. The study reveals that pine performance drops significantly once aspen density exceeds specific ecological thresholds, which differ between the moist Sub-Boreal Spruce and the drier Interior Douglas-fir zones. This document serves as a management guide for foresters, offering scientific recommendations on the maximum amount of aspen that can be retained in young stands without compromising timber productivity.

This document introduces a field study in British Columbia designed to move away from creating forest monocultures and toward sustainable mixedwood management. The text contrasts traditional unmixing practices with a new experimental project that tests alternative brushing treatments, such as manual cutting and localized chemical applications. By comparing six different methods across established plots, the authors aim to determine how to best promote white spruce growth while maintaining the ecological and economic benefits provided by trembling aspen. This document serves as an early record of the site's characteristics and the long-term research objectives required to balance timber yields with biodiversity and ecosystem stability in the boreal forest.

This technical report evaluates the early effects of manipulating trembling aspen density on the development of lodgepole pine stands within the dry Interior Douglas-fir zone of British Columbia. By establishing an experiment near Meldrum Creek, researchers analyzed how different levels of aspen retention impacted conifer growth, vigor, and survival over a four-year period. The study found that while thinning immediately altered the stand structure and reduced aspen basal area, it did not yet yield significant improvements in pine performance, likely due to the young age of the trees and slow growth rates in this climate. Additionally, the report explores the competitive neighbourhood, identifying that aspen within a one-meter radius are the most influential competitors, while also noting that higher aspen retention may help suppress the density of new suckers. This research serves to refine competition thresholds and provide forest managers with biological data to optimize mixedwood management and free-growing guidelines in the region.

This document evaluates the long-term viability of planting native broadleaf trees as a reforestation strategy in British Columbia's Cariboo region. By tracking species like aspen, birch, and cottonwood alongside traditional conifers over a ten-year study period, the authors discovered that planted broadleaves suffered from poor survival rates due to wildlife browsing, frost, and competition from grass. While these deciduous trees naturally excel at enhancing soil nutrients and providing frost protection for understory seedlings, the study concluded that they are currently less reliable than conifers when manually planted. This document suggests that while broadleaves remain vital for forest biodiversity and health, their successful management in this region relies more on robust natural regeneration than on artificial cultivation.

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 serves as a comprehensive manual for commercial thinning within the province of British Columbia, detailing how to manage intermediate harvests where the wood removed covers extraction costs. The text outlines a multi-level strategy that integrates strategic planning at the landscape level with specific stand selection criteria, such as windfirmness, tree stability, and forest health. Its primary purpose is to offer practitioners a framework for using thinning as a strategic management tool to increase wood flow flexibility, enhance timber value, and protect non-timber resource values like biodiversity and visual landscapes. Furthermore, the guidelines establish strict administrative and legal requirements under the Forest Practices Code, mandating detailed silviculture prescriptions and rigorous post-harvest assessments to monitor soil disturbance and residual tree damage.

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 investigates the effectiveness of different harvesting methods for establishing Douglas-fir regeneration in the dry climate of British Columbia's interior. By comparing clearcutting against shelterwood systems, which retain partial tree canopies, the authors examine how varying levels of shade and protection influence the survival and size of new trees. The study found that while individual tree growth and crown volume were most robust in clearcut areas, the shelterwood treatments significantly improved the density of natural regeneration. This document suggests that a heavy-removal shelterwood may offer the ideal balance, providing adequate growth rates while acting as an insurance policy for a fully stocked forest.

This document summarizes a decade of experimentation aimed at balancing timber extraction with the preservation of northern caribou habitat in British Columbia. The document outlines various alternative silvicultural systems, such as irregular shelterwood and group selection, to protect the terrestrial and arboreal lichens essential for caribou winter survival. Beyond wildlife management, the text evaluates how these harvesting methods influence forest regeneration, microclimate stability, and windthrow risk compared to traditional clearcutting. This document serves as a scientific foundation for regional recovery plans and sustainable land-use strategies for threatened species in the Southern Interior Forest Region.

This document evaluates the long-term effectiveness of various silviculture practices and forest management techniques across the Engelmann Spruce-Subalpine Fir zones of British Columbia. By assessing historical research trials and logged areas in the southern interior, the document details why certain methods lead to regeneration success or failure, specifically noting the challenges of competing vegetation and harsh environmental conditions. The document is structured to provide a comprehensive analysis of site preparation methods, planting outcomes, and the quality of remaining trees, ultimately revealing that initial spruce growth is often slow and survival rates are frequently unsatisfactory. This document concludes with strategic recommendations for future study to better understand how elevation and plant competition influence the sustainable recovery of these high-altitude ecosystems.