63 resources found

This paper details a study conducted in the southern mountains of British Columbia to assess the survival and growth of planted Engelmann spruce and subalpine fir seedlings in different sizes of harvested forest openings. The researchers compared seedling performance across various silvicultural systems, noting that survival generally decreased with smaller opening sizes, while growth was best in larger clearcuts. The study aimed to provide insights into effective regeneration practices for high-elevation forests, considering factors like opening size, local climate, and species response.

This paper details an experimental crown fire conducted in an Alberta, Canada, boreal black spruce forest to assess the effectiveness of recent crown thinning as a fuel treatment. Researchers ignited a 3. 6-hectare fire, observing its behavior in both untreated and thinned sections. The key finding was that while thinning led to a significant reduction in fire intensity, it did not reduce the fire's spread rate nor total fuel consumption. This suggests that in dense boreal black spruce with high surface fuel loads and low crown base heights, thinning alone may not prevent the rapid progression of crown fires, but it could potentially aid suppression efforts by reducing the intensity.

This study investigates how commercial thinning impacts the growth, yield, and mortality of natural lodgepole pine forests in Alberta, Canada. Faced with a predicted timber shortage due to fires and mountain pine beetle infestations, the research explores thinning as a strategy to increase mid-term sawlog supply by accelerating tree growth and enabling earlier timber access. The findings reveal that while thinned stands initially show less volume, they ultimately demonstrate a greater cumulative volume gain when factoring in the wood removed during thinning. This benefit stems from increased individual tree diameter and live crown ratio for remaining trees and a significant reduction in overall tree mortality, particularly among smaller trees.

This paper explores operational resilience in western U. S. frequent-fire forests, emphasizing how historical forest structures fostered health and adaptability. The authors argue that very low tree densities prior to widespread fire suppression minimized competition, which in turn supported vigorous tree growth and greater resistance to stressors like drought and bark beetles. By comparing historical data with contemporary forest conditions using the Stand Density Index, the authors found a significant increase in tree density and competition today. This sugests that current management practices, which are focused primarily on fuel reduction, may not adequately restore the ecological resilience historically maintained by frequent, low-intensity fires. The paper advocates for a fundamental rethinking of forest management to prioritize significantly lower tree densities and minimal competition to enhance long-term forest health.

This document investigates the long-term effects of pre-commercial stand thinning in lodgepole pine forests in British Columbia, specifically examining 30-year responses across a range of thinning densities. The central focus is on whether heavy thinning can simultaneously enhance forest productivity, measured by merchantable wood volume and carbon storage, and accelerate the development of old-forest structural attributes important for wildlife conservation. Findings revealed that heavy thinning did create large dominant trees with substantial crowns and other old-growth features, partially supporting the goal of restoration of old-forest structural attributes, and restored much of the lost carbon storage through crown growth. This study suggests that the structural complexity created by heavy thinning, rather than forest age alone, may be sufficient to sustain comparable total abundance, species richness, and diversity of forest-floor small mammals to that found in old-growth stands, highlighting a viable silvicultural approach to address timber needs and ecological restoration.

This document investigates how to balance forestry interests with the survival of mountain caribou in British Columbia, specifically by moving away from clearcutting silvicultural systems. Because caribou rely on arboreal lichens found in old-growth forests for winter sustenance, traditional logging methods that remove all tree cover effectively destroy their primary food source and increase predation risks. The authors propose and test selection silvicultural systems, such as single-tree or group harvesting, which aim to extract timber while perpetually retaining stand characteristics necessary for caribou habitat. Through field trials, the study monitors how these partial-cutting techniques affect lichen biomass and growth rates, concluding that such methods should be integrated into a broader landscape-level strategy that includes designated no-harvest refugia.

This paper investigates how different forest harvesting methods impact both the amount of carbon stored and the variety of plant and tree life. The study compared the effects of clearcutting, varying levels of partial tree retention, and no harvesting across different climatic regions in British Columbia's Douglas-fir forests, ranging from humid to semi-arid. The central finding is that the intensity of harvesting significantly influences carbon storage and biodiversity, but importantly, the magnitude of these effects is strongly linked to the regional climate.

This paper investigates the patterns of post-fire vegetation regeneration in two climatically distinct sites in Waterton Lakes National Park, Canada, following a severe montane fire and subsequent abnormally dry conditions. The study aimed to quantify the recovery trajectories of herbaceous understory and conifer seedlings over five years, revealing that site environmental conditions were more influential than inter-annual drought in determining recovery. Notably, the moist site exhibited greater herbaceous biomass accumulation while the drier site demonstrated significantly higher lodgepole pine seedling recruitment, indicating a complex ecological resilience to drought in fire-prone montane ecosystems. This paper affirmed the utility of remotely piloted aircraft systems for spatially monitoring changes in vegetation height, cover, and biomass after a disturbance.

This paper examines the complex relationship between forest health and climate change from a British Columbia perspective, building on the impact of past events like the mountain pine beetle and Dothistroma needle blight epidemics. The authors present estimations of how various forest pests are expected to behave as climate continues to change, emphasizing that rapid environmental shifts are favoring fast-reproducing pests over long-lived trees. The research offers management recommendations aimed at increasing forest resilience, such as implementing assisted migration and genetic diversity, while stressing that the future of forest management requires flexibility and adaptation in the face of unprecedented uncertainty. The purpose of this paper is to equip managers with projections for the near future and emphasize the urgency of integrating proactive forest health measures into all aspects of land-use planning.

This document introduces the concept of fire-smart forest management as a pragmatic approach to achieving sustainable forest management in Canada's fire-dominated ecosystems. The core challenge addressed is how to simultaneously minimize the socioeconomic impacts of fire while maximizing its ecological benefits, objectives that have historically been seen as contradictory. Fire-smart forest management integrates both forest and fire management activities, from stand to landscape levels, through proactive planning, such as altering forest fuels to reduce the potential for undesirable wildfires and lessen the risks associated with prescribed burning. This new paradigm is necessary because traditional aggressive fire suppression is reaching its maximum effectiveness, necessitating a shift in attitude to embrace fire's essential ecological role and mitigate its negative effects through integrated management strategies.

The Montane Alternative Silvicultural Systems trial was designed to compare the ecological effects of traditional clearcutting against alternative silvicultural systems regarding forest nutrient dynamics in coastal British Columbia. Researchers observed that while harvesting led to a slight, short-lived increase in soil nitrogen availability, the resulting fluxes of nitrogen below the rooting zone were negligible. A key finding was that mineralized nitrogen remained predominantly in the form of ammonium, and subsequent nitrate increases were primarily due to decreased microbial consumption rather than increased production. The study concluded that since the estimated nitrogen losses from the rooting zone were minimal compared to vast soil reserves and natural atmospheric inputs, harvesting is unlikely to negatively impact future site productivity.

This study aimed to identify viable silvicultural alternatives to conventional clearcutting for promoting successful forest renewal in black spruce stands across the eastern Canadian boreal zone. Researchers evaluated whether partial harvesting techniques, specifically variations of shelterwood and seed-tree cutting, could achieve adequate conifer density over a ten-year period. The results confirmed that these partial harvest methods, when implemented alongside mechanical site preparation such as spot scarification, successfully facilitated sufficient density of black spruce regeneration. The research supports the use of shelterwood and seed-tree systems combined with soil disturbance as effective management strategies for meeting sustainable forest productivity objectives.

This paper investigates how the post-fire regeneration of trembling aspen is affected by the unique conditions of a high-severity boreal wildfire, specifically the Chuckegg Creek Fire in Alberta, Canada. The study's primary finding is that the success of aspen recruitment, either through vegetative suckering or seedlings, is strongly determined by surface fire severity and the timing of the burn relative to spring green-up. High surface fire severity, especially after green-up, decreased suckering by damaging root systems but simultaneously promoted the establishment of seedlings, effectively filling the regeneration gap and highlighting an alternative path for the foresta?Ts ecological resilience against intense disturbances. The paper concludes that a landscape mosaic of fire severities is crucial for maintaining both the long-lived clonal persistence and the necessary genetic diversity provided by sexual reproduction.

This paper provides an ecological and management overview of the old-growth forests in Canada's Montane Cordillera, a region spanning British Columbia and Alberta known for having the nation's most diverse range of old-growth coniferous forests due to its varied climates and natural disturbance regimes. The author emphasizes that a forest's history of climate and disturbance profoundly influences the abundance and structure of old-growth stands, noting that wetter climates support more abundant old forests and old-growth-dependent organisms, such as epiphytic lichens. The text critiques the challenges of defining old-growth, which is often arbitrary and dependent on an ecologist's viewpoint, and highlights the urgent need for a better ecological understanding to make informed land-use decisions for both the wet-belt rainforests and the drier forests, which are heavily impacted by human activities.

This paper examines ecosystem management strategies for the paludified boreal forests of Canada, emphasizing how to simultaneously enhance wood production, biodiversity, and carbon sequestration. The authors delve into how natural disturbances, particularly fire severity, influence forest dynamics, soil properties, and the diversity of plant and invertebrate communities. They then contrast these natural processes with the impacts of different logging methods on soil, productivity, and understory vegetation, highlighting how traditional clearcutting and careful logging compare to natural fire regimes. Finally, the paper discusses the critical role of these forests in carbon sequestration and proposes management approaches that emulate natural disturbances to maintain old-growth forest characteristics and mitigate climate change.

This paper introduces the retention system, a silvicultural system to align forest management with the principles of ecosystem management, moving beyond a singular focus on sustained production of timber. This system is specifically designed to implement the variable retention approach to harvesting, which prioritizes retaining trees and structures for ecological objectives, such as maintaining structural heterogeneity and protecting biological legacies. The paper argues for the necessity of this new terminology to clearly convey the intent of management where the maintenance of ecological complexity is as crucial as traditional yield expectations, acknowledging that these goals may reduce timber productivity. The retention system is defined by its requirement to maintain long-term structural diversity and ensure forest influence over the majority of the harvested area.

This paper addresses the severe decline of High Elevation Five-Needle White Pine forests in western North America, primarily due to mountain pine beetle outbreaks, white pine blister rust, and altered fire regimes exacerbated by changing climates. The authors advocate for multi-scaled management interventions to promote resilience to disturbances and genetic resistance to white pine blister rust. The paper details the critical need for long-term programs like inventory, mapping, and research, alongside active restoration treatments such as mechanical cuttings and prescribed fires, and proactive tree-level measures like planting rust-resistant seedlings and protecting high-value trees, all while integrating climate change considerations throughout the planning and implementation process.

This research compiles and analyzes a national database of dead and down woody debris to improve fire behavior and effects modeling in Canadian forests. The study emphasizes that DWD is a major component of surface fuels, significantly impacting fire intensity, consumption, and the transition to crown fires. By examining various forest types and ecozones, the authors identified key predictive variables such as bioclimatic regime, age, and structural components. This work provides crucial tools for a more accurate understanding of DWD distribution across Canada, enhancing the country's ability to forecast and manage wildfires.

This report introduces a quantitative old-growth index specifically designed for Douglas-fir forests in central British Columbia's Interior Douglas-fir zone, particularly in the IDF_dk_3 and IDF_dk_4 biogeoclimatic variants. Recognizing that traditional age-based definitions of old growth are insufficient for forests frequently impacted by disturbances, the authors developed an index based on measurable structural attributes like tree size, canopy complexity, and the presence of dead trees. This index aims to provide forest managers with a consistent tool to identify and classify old-growth stands into four seral stages, helping guide management practices for biodiversity conservation and the enhancement of old-growth characteristics. The study emphasizes that this index relies on expert professional judgment to quantify what constitutes old-growth attributes in these specific forest types.

This document introduces an innovative old-growth index developed to accurately measure and track the ecological value of forests, especially those prone to disturbances. Moving beyond traditional age-based definitions, the researchers used Aerial Laser Scanning (ALS) and field data to create a more comprehensive metric that considers diverse structural attributes like tree size, deadwood, and canopy complexity. The study's application in British Columbia's Chinook Community Forest revealed that "very-high" old-growth value forests are scarce and fragmented, often located outside designated protected areas. This research provides a flexible and robust framework for forest managers to better conserve and monitor these vital ecosystems and their services, aiding in more effective landscape-level planning.