18 resources found

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 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 document investigates how silvicultural thinning and nitrogen fertilization affect the abundance and variety of plants growing beneath the canopy in Douglas-fir plantations. By tracking 21 experimental sites over more than a decade, the authors discovered that reducing tree density generally increased species richness, while adding nutrients significantly decreased understory cover and diversity. It was identified that these changes were not merely a result of light availability since fertilized plots saw a dramatic decline in plants even when light levels were sufficient, therefore suggesting factors like ammonia toxicity or shifted competition played a role. This document highlights that intensive forest management practices significantly reshape understory community composition, often in ways that contradict ecological models of resource availability.

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.

This extension note serves as a practical guide for silvicultural practitioners. It addresses critical operational concerns identified by the forestry community, specifically focusing on competing vegetation and forest health. The core of the document presents Stand Establishment Decision Aids for nine distinct forest health issues prevalent in the Southern Interior Forest Region of British Columbia, such as the black army cutworm, various root diseases, and blister rusts. Each SEDA provides essential information on identifying susceptible stands, understanding the biology of the damaging agent, and outlining relevant harvest and silviculture considerations, including regeneration and plantation maintenance strategies, ultimately aiming to support informed decision-making for healthy forest establishment.

This document reports on a government initiative, the Silvicultural Systems Program, established in response to public criticism of widespread clearcutting in British Columbia's forests starting in 1990. The paper describes the program's goal of exploring and demonstrating diverse forest harvesting practices through numerous large-scale, long-term experiments across the province. It outlines the program's history, funding, and key accomplishments, including the operational feasibility and varied environmental impacts of alternatives to clearcutting, and concludes by offering lessons learned for future large-scale forestry research endeavors and reflecting on the challenges of translating research into widespread changes in forestry practices.

This document addresses the challenge of balancing timber harvesting with the conservation of at-risk plant communities that depend on mature and old forest conditions in British Columbia's Coastal Douglas Fir biogeoclimatic zone. Recognizing the scarcity of these older forests, the document outlines silvicultural practices aimed at maintaining existing structural diversity in high-conservation areas and accelerating the development of old-growth characteristics in younger, more homogenous stands. Ultimately, it seeks to equip forest professionals with strategies to enhance the ecological functions of older forests within provincial forest lands.

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 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 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 investigates the economic viability of commercial thinning in second-growth forests on British Columbia's coast. Using the TIPSY 4.2 modeling software, the author simulates various scenarios by inputting existing forest data and economic variables to predict stand yields and financial outcomes. While acknowledging the environmental and silvicultural benefits of commercial thinning (like improving stand quality, accelerating wood volume, and enhancing biodiversity) the study's initial findings suggest that, under current conditions, commercial thinning is not economically feasible. However, it also explores the potential for future use, considering factors such as different thinning intensities, harvesting methods, and the impact of government assistance programs.

This report outlines the Montane Alternative Silvicultural Systems study, a large-scale project designed to test the ecological and operational feasibility of harvest methods beyond conventional clearcutting in coastal British Columbia montane forests. The research examined the biological and silvicultural impacts of four systems, including clearcut, patch cuts, green tree retention, and shelterwood, to address concerns regarding regeneration, aesthetics, and biodiversity in challenging high-elevation environments. Key findings indicated that while clearcutting was often the most cost-effective, alternative systems faced specific issues, such as increased operational costs and shade limitations that suppressed seedling growth in the shelterwood treatments. The results offer actionable implications, suggesting that small patch cuts and low retention levels can be successfully implemented without significantly reducing early plantation performance.

This paper explores silviculture strategies applicable in British Columbia's designated northern caribou ranges. It addresses the critical intersection of forestry practices and caribou conservation, especially in light of the mountain pine beetle infestation and resulting salvage logging. The paper synthesizes current scientific research to provide guidelines for managing forest stands to maintain or improve caribou habitat, considering their ecology, legal protections, and the potential impacts of forestry operations. The paper aims to offer practical silvicultural options that balance timber harvesting with the conservation of this sensitive species and its habitat.

This extension note explores managing British Columbia's forests to act as ongoing carbon sinks in the face of a warming climate. It emphasizes that forest management for carbon sequestration needs to consider the likely changes in natural disturbances and offers various silvicultural tools and landscape-level strategies that managers can employ. The extension note highlights the importance of balancing carbon objectives with other forest values like biodiversity and timber production, acknowledging the complexities and uncertainties of long-term climate impacts.

This document present a strategy for the utilization and management of deciduous tree species, particularly red alder, big leaf maple, and birch, within the coastal forests of British Columbia. The paper outlines objectives for hardwood management, discusses different management strategies, and considers crucial aspects like timber supply, relevant legislation, and geographic considerations for successful implementation. It serves as a guide for forest professionals and decision-makers to support and expand hardwood management in the region, aiming to diversify the coastal fibre supply and ensure a sustainable flow of timber products.