66 resources found

This FRDA Report #094 investigates how manipulating stand density and applying fertilization affected the long-term development of immature Coastal Douglas-fir stands in British Columbia. Researchers monitored test plots over a decade, examining how various spacing regimes influenced tree metrics. The findings indicated that the combined treatments significantly improved stand volume growth, with fertilization providing a strong, immediate response that waned over time. The reduced density plots demonstrated the most pronounced and sustained positive results throughout the ten years after treatment.

This FRDA Report #097 investigates the net basal area response of Douglas-fir trees to nitrogen fertilization in stands that have been thinned and unthinned. The research, based on a 9-year study in British Columbia, developed equations to predict how fertilization affects tree growth and focused on how thinning influences the effectiveness and longevity of fertilizer application. Key findings indicate that thinned stands show a greater and more persistent response to nitrogen fertilization compared to unthinned stands where the effect tends to dissipate more quickly. The study provides valuable insights for forest managers on optimizing silvicultural practices by combining thinning and fertilization to enhance Douglas-fir productivity.

This FRDA Report #137 investigates the basal area response of immature coastal western hemlock stands to fertilizing and thinning treatments on northern Vancouver Island, nine years after application. The purpose is to understand how these silvicultural practices affect tree and stand growth, particularly focusing on net basal area response, which is a measure of the cross-sectional area of tree trunks. The study found that while thinning alone significantly improved growth, the best results were achieved by combining fertilization with thinning, as this concentrated the additional growth onto fewer, more valuable stems, even though the total basal area removed by thinning was not fully recovered within the nine-year period. The research also provides equations for estimating net basal area response, offering practical tools for forest managers considering these interventions.

This FRDA Report #021 details a 35-year study on the effects of commercial thinning on 50-year-old Douglas-fir stands on Vancouver Island. The study compared thinned and unthinned plots to analyze growth and yield metrics such as total volume, diameter, and mortality. While thinning led to a 12% increase in potentially usable total volume yield over the study period and produced larger diameter trees overall, it also resulted in an 18% reduction in total volume at final harvest compared to unthinned stands. The study suggests that commercial thinning provides earlier wood availability and larger trees, but does not significantly alter total gross annual growth or crop-tree size, offering valuable data for forest management models and strategies.

This FRDA Report #166 details a study conducted in British Columbia in 1991 where the central focus is on methods of timber harvesting, specifically partial cutting and helicopter yarding, in ecologically sensitive floodplain areas within old-growth hemlock-spruce forests. The case study explores the environmental impacts and effectiveness of these yarding techniques in such delicate ecosystems.

This FRDA Report #247 details a study comparing different methods of harvesting trees in a coastal montane forest in British Columbia. Prompted by concerns about regeneration success at higher elevations and public desire for alternatives to clearcutting, the Montane Alternative Silvicultural Systems project investigated the productivity and costs associated with uniform shelterwood, green tree retention, and patch cutting compared to traditional clearcutting. The study tracked the efficiency and expense of falling and forwarding operations, alongside measuring the impact on soil disturbance and the amount of remaining woody debris. Ultimately, the research aimed to provide insights into the economic and operational feasibility of alternative silvicultural systems in this challenging environment, while also considering their long-term ecological effects.

This FRDA Research Memo #241 details a study in the North-Central Interior of British Columbia comparing the effects of different site preparation treatments on the growth of lodgepole pine and hybrid white spruce seedlings. The research specifically investigated broadcast burning, disc trenching, pile-and-burn, and no treatment, analyzing their impact on soil conditions and seedling performance, including height and root growth after multiple growing seasons. Key findings indicated that disc-trenching and broadcast burning were the most effective methods for improving growth by enhancing soil properties, whereas the pile-and-burn treatment sometimes led to detrimental soil compaction due to excavator tracks, which hindered root development. Although site preparation was not necessary for high seedling survival on this particular wet, cool site, certain treatments were clearly beneficial for maximizing growth.

This study documents the Montane Alternative Silvicultural Systems project, a long-term cooperative study on Vancouver Island, British Columbia, established to find forest management practices that could replace conventional clearcutting in high-elevation coastal environments. This research initiative evaluated the operational, economic, and biological consequences of alternatives like patch cuts, green tree retention, and shelterwood logging. The findings cover crucial metrics such as operational costs and feasibility, as well as detailed ecological and silvicultural impacts on forest regeneration, soil health, and local biodiversity. The purpose of the MASS research was to provide the scientific foundation needed for implementing environmentally sustainable harvesting systems, such as variable retention, in the region's complex montane forests.

This document investigates the effectiveness of various thinning, pruning, and residue fuel management strategies designed to mitigate extreme wildfire hazards in the fire-prone forests of interior British Columbia. Using both simulated scenarios and analyses of actual operational treatments, the research modeled impacts on passive and active crown fire potential, as well as tree mortality. A key finding is that while removing small trees reduces the risk of passive crown fire, the concurrent removal of some larger trees is necessary to substantially reduce the threat of active crown fire. The study also confirmed that effective management of residue fuels is critical for treatment success, while pruning was found to have minimal impact on crown fire mitigation. This work provides valuable, region-specific data to help forest managers make informed wildfire management decisions regarding necessary treatment intensity.

This report details the 26-year results of the Montane Alternative Silvicultural Systems Project, an integrated, long-term study designed to evaluate the biological consequences of different harvesting approaches in montane coastal forests of British Columbia. Researchers quantified changes in understory vegetation cover, diversity, and conifer regeneration across four systems, including clearcutting and various forms of tree retention, compared to an old-growth benchmark. The study found that while all harvesting methods led to an eventual increase in overall species richness, the uniform shelterwood retained more stand structure and pre-harvest plant species initially. The findings suggest that the retention of relatively intact mature forest patches is the most effective approach for conserving plant and non-vascular species associated with older forests.

This research documents a six-year monitoring study at the Montane Alternative Silvicultural Systems site, examining how different harvesting methods influence the likelihood of windthrow damage in coastal montane forests. The study quantified stem loss across four treatments, including clearcut, shelterwood, green tree retention, and patch cut, finding that windthrow losses were substantial across the site, which was not initially considered high risk. Although low-density green tree retention experienced the highest proportion of damaged trees, the overall greatest number of wind-damaged stems occurred in the shelterwood treatment. The data indicates that small, concentrated patch cuts resulted in the lowest amount of windthrow, suggesting that grouped retention is a more effective strategy than dispersed retention for minimizing wind damage. The authors conclude that adopting group retention strategies can better conserve structural forest elements while addressing challenges related to windthrow risk.

This document on the 26-year assessment of the Montane Alternative Silvicultural Systems evaluates the success of planted Amabilis fir and Western Hemlock seedlings established in 1994. The core purpose of the MASS study is to measure the impact of four distinct establishment treatments, including control, fertilization, herbicide, or a combination, on tree growth over time. These treated plots are systematically mapped within the context of various silvicultural harvesting systems, including clearcut, green tree, patch cut, and shelterwood. The images act as an inventory, identifying the specific plot numbers selected for the 2019 photographic evaluation of the long-term experimental outcomes within each system.

This document on the 26-year assessment of the Montane Alternative Silvicultural Systems study focuses on natural regeneration and understory species within various managed forest environments. The MASS study is highly structured, comparing distinct silvicultural systems such as clearcut, shelterwood, and old growth by utilizing three separate replicates for each treatment type. Data collection relies on establishing Permanent Vegetation Plots, which incorporate smaller, precisely defined nested sub-plots to monitor detailed plant life, including herbs, bryophytes, and tagged conifer species like Amabilis fir and Western Hemlock. These images function as a structured index, associating specific plot and photo numbers with each experimental manipulation across the research site.

This comprehensive 15-year report details the Montane Alternative Silvicultural Systems Project, which tested the efficacy of different harvesting treatments, including clearcutting, patch cutting, and various forms of retention, on forest health and regeneration in coastal British Columbia. Key findings reveal that while conifer survival remained consistent across treatments, tree height and volume growth was generally slower in the shelterwood environment due to reduced light, and the single most effective way to boost planted tree growth was through intensive vegetation control. Conversely, the shelterwood system successfully maintained the greatest understory species diversity and composition most similar to the uncut old-growth forest, minimizing the loss of shade-loving plants. The long-term data emphasizes a crucial trade-off: maximizing early conifer growth favors more open treatments, but retaining pre-harvest biodiversity values is best achieved with substantial canopy protection.

The Montane Alternative Silvicultural Systems project is a 25-year study designed to evaluate how different harvesting methods impact regeneration, wildlife habitat, and aesthetics at high elevations on Vancouver Island. This research compared standard clearcutting with three alternative silvicultural systems including patch cut, green tree, and shelterwood, while tracking the growth and survival of five conifer species. The findings revealed that planted Douglas-fir was the fastest growing species across all treatments, despite experiencing the highest rate of mortality. The research also confirmed that post-planting efforts such as vegetation control significantly improved the volume and growth of species like western hemlock and amabilis fir over the long term.

This study, conducted at the Montane Alternative Silvicultural Systems site, investigated the phenomenon of growth check in young amabilis fir trees, characterized by a sharp decline in annual height increment approximately ten years after planting. Researchers hypothesized that this severe growth limitation was linked to aggressive competition from ericaceous shrubs, such as Vaccinium species, resulting in limited nutrient availability, particularly nitrogen deficiency. By comparing different harvest treatments and the use of early herbicide treatment, the study concluded that vegetation control was the most significant factor in maintaining growth - trees without herbicide were often severely stunted and exhibited greater Vaccinium cover. The findings establish that high shrub competition coupled with low foliar nitrogen are reliable indicators for diagnosing and predicting this critical growth failure on coastal montane sites.

This document introduces specialized Stand Density Management Diagrams to assist forest managers in British Columbia with planning the optimal growth and yield of even-aged stands of lodgepole pine, white spruce, and interior Douglas-fir. These graphical tools function by depicting the temporal relationships among forest metrics, including stand density, top height, and mean tree volume, derived from the TASS growth simulation model. Silviculturists can use the SDMDs to visualize various growth paths, determine the optimal timing and intensity of thinnings, and make preliminary yield estimations for different management objectives. The diagrams map out the Zone of Imminent Competition Mortality and the density range for maximizing Current Annual Increment, providing essential information for maximizing timber production while minimizing losses.

This document details a study on the effect of commercial thinning on within-stand microclimate and fine fuel moisture in a mature lodgepole pine forest in southeastern British Columbia. Researchers compared thinned and unthinned stands, observing that thinning led to decreased rainfall interception and increases in solar radiation, wind speed, and near-surface air temperature. While fine fuel moisture content was lower in the thinned stand immediately after rain, these differences became very small under moderate and high fire danger conditions, suggesting minimal practical impact on ignition probability or crowning potential at those times. The study also validated the effectiveness of the Fine Fuel Moisture Code component of the Canadian Fire Weather Index System for predicting fuel moisture in both stand types during critical fire danger periods.

This core purpose of this document is to present ideas and case studies demonstrating how to integrate ecological restoration into routine forest management practices to enhance biodiversity, reduce risks, and achieve sustainable certification. This document outlines key ecological issues, such as landscape fragmentation and the loss of natural stand structural elements, and details corresponding restoration approaches across eleven distinct case studies, from restoring open forest and open range through commercial thinning to mitigating road impacts and restoring riparian habitat integrity. Finally, the document prioritizes specific forested ecosystems with high priority restoration needs in BC, offering tailored solutions for zones like the Interior Douglas-fir and Coastal Western Hemlock.

This document is a detailed report summarizing a commercial thinning experiment in the Horsefly Forest District in British Columbia. The primary goal was to assess the operational feasibility of commercial thinning as an alternative silviculture treatment, particularly focusing on developing higher-valued timber stands. The report delves into numerous technical and environmental issues, including desired crop tree characteristics, hydrological stability, and windthrow and snow-damage, backed by exhaustive production reports from the harvesting machinery and detailed snow breakage and crown growth surveys. The study concluded that commercial thinning is an operationally viable option within the Cariboo Forest Region, providing continued access to merchantable stands.