Best Management Practices (BMPs) for timber harvesting in Endangered Williamson’s Sapsucker Critical Habitat were published in 2014. These established several live tree (>17.5-cm dbh) retention targets in cutblocks (with a minimum of 85 live tree stems per ha (sph) and a maximum of over 225 sph) to maintain suitable habitat of Williamson’s Sapsucker. We first reviewed the rationale for the targets and found them well supportednby analyses of independent datasets. These datasets included locations of nests in cutblocks relative to sph, direct observations of adults foraging from nests, foraging stand preferences based on radio-telemetry, tree densities at nests versus unoccupied sites, and breeding occupancy of cutblocks. Williamson’s Sapsucker avoided stands with <100 sph and >400 sph. Examination of 113 cutblocks approved after 2014 that contained Critical Habitat for Williamson’s Sapsucker found that 62% did not retain even the minimum 85 sph targetsnof the BMPs, largely because application had been voluntary. The live tree retention targets will need to be met by selection harvesting and silvicultural systems at the hectare scale, i.e., not averaged over whole cutblocks, because any portions of cutblocks with <100 sph would be lost habitat that could not be replaced by averaging over portions of the block that may be more densely treed.
British Columbia’s interior forests have been heavily subjected to logging, burning, and beetle outbreaks for decades. Partial retention forest harvesting may be a method that could mitigate some of the negative effects of clearcut harvesting on wildlife. We conducted live trapping for small mammals at John Prince Research Forest in north-central BC to estimate species diversity, population density, and habitat use across a gradient of overstory tree retention. We detected 7 species, with diversity highest in the uncut forest (control) relative to the clearcut (control mean Shannon Index = 1.01, SE = 0.14) and partial retention treatments (30% and 60% retention, mean Shannon Indices = 0.99, 0.98; SE = 0.17, 0.17), and significantly lower in the seed tree treatment (mean = 0.63, SE = 0.17, p = 0.02). Greater population densities of North American deer mouse (Peromyscus sonoriensis) and southern red-backed vole (Myodes gapperi) in partially harvested stands, as estimated with spatially explicit capture-recapture models, support these practices for supporting populations of forest specialists. More experimental approaches to forest operations are needed across larger spatial scales, such as adaptive management of forest harvest methods with rigorous wildlife monitoring to ensure ecological objectives are met.
The western balsam bark beetle, Dryocoetes confusus Swaine, is ubiquitous throughout mature subalpine fir ecosystems in British Columbia and is considered the most serious mortality-causing disturbance. Harvesting subalpine fir has increased recently; however, little is known about how this anthropogenic disturbance affects the population dynamics of D. confusus. Using high resolution photography and ground surveys, this study compared stand composition and D. confusus attack levels along natural forest edges and edges created by harvest <10 years or >15 years ago, to forest interiors, where no anthropogenic disturbance had occurred. Subalpine fir density and D. confusus attack were lower in natural forest edges than in harvested edges. There were differences in attack levels between harvest treatments, but the overall impact by D. confusus was similar to D. confusus-caused mortality seen in forest interiors. More recent attack differed among edge treatments, with the highest levels in the <10 years since harvest treatment and the lowest levels in natural edges. This short period of increased activity by D. confusus post-harvest has minimal
Wolverine den in snowy areas with boulders or woody debris at or below tree line in montane western North America. They have naturally low reproductive rates, a fidelity to denning areas, and a sensitivity to human presence during denning. The goal was to synthesize existing ecological information for denning wolverine and identify risks from human presence in the categories of timing, distance, footprint, pattern of use, and frequency of use. The authors suggest commercial tenure holders and private users keep recreation in the low-risk category to minimize disturbance on denning females. Denning area surveys should be conducted prior to tenure application or renewals and dens can be identified by a concentration of tracks over more than three weeks from January 15 to May 15. Recreation should be restricted within a 5-km radius of confirmed dens during this window. Best practices include limiting the number of groups and concentrating movement on existing linear features as wolverine are sensitive to disturbance at a very low intensity of use and are at greatest risk when disturbances are dispersed and unpredictable.
The Indigenous peoples of British Columbia (BC) have a long and deep tradition of cultural burning. It was an important component of many of BC’s ecosystems until colonial authorities systematically discouraged the practice from the 1870s onwards. Eventually the beneficial role of fire was recognized, particularly in dry interior (NDT 4) ecosystems. To help validate those traditional practices, this article draws on settler and Indigenous accounts of First Nations cultural burning in BC.
Wildland fire has long been recognized as an important disturbance to consider in natural resource management in British Columbia (BC), Canada. Fuel reduction treatments are conducted to achieve designated fuel load targets, measured as the weight of the remaining fuel per unit area (tonnes/hectare [t/ha]). Multiple methods are available to professionals for measuring hazard abatement, but this prevents standardization of data for comparison across the province. To promote a study based in science but through an operational lens, the authors used freely available BC Government documents and guidebooks to perform the fuel measures and fuel load tallies. Thirty-two fuel plots were established in the summer of 2021 within the Burns Lake Community Forest. Field measurements were carried out following mechanical raking treatments to determine if units within the ‘severe’ fuel hazard threshold (FHT) met the target fuel load of 1–5 t/ha. Less than one-third of the plots had a fuel load within the target range. Implications of results are discussed, and several recommendations are proposed to improve the feasibility of post-harvest fuel mitigation practices, including a streamlined fuel measurement methodology and more flexible fuel load targets that would enable better comparisons of treatment feasibility across different fuel types and ecosystems within the province.
Not all pests kill trees or compromise final tree form; however, the cumulative effect of one or more damage agents over time can significantly limit final expectations at harvest, severely reducing or compromising wood quality and timber supply expectations going forward. This study highlights the effects of damage agents on young lodgepole pine insouthern British Columbia during the formative years of stand development. Over 4,300ntrees were monitored for up to three decades with over 40 damage agents recorded, causing significant repercussions on stocking, health, and form of potential crop trees. By the final assessment, density of potential crop trees had declined dramatically, with 84% affectedby one or more pests, and 63% of natural ingress dead. Most natural ingress was severely suppressed; thus, it is unlikely to fill in stand gaps caused by mortality and damage agents affecting larger potential crop trees. Lodgepole pine terminal weevil and western gall rust were the predominant damage agents influencing form and quality of potential crop trees. Lodgepole pine terminal weevil attacked up to 73% of pine and over 24% suffered multiple attacks. Results from this study emphasize the need for more short- and long-term monitoring of young stands to inform the development of forest policy and promote healthy, resilient new forests. KEYWORDS: lodgepole pine, damage agents, lodgepole pine terminal weevil, western gall rust, Southern British Columbia
Whitebark pine (Pinus albicaulis) is a high-mountain keystone and foundation species that is declining throughout most of its range in Western Canada. An introduced pathogen (Cronartium ribicola) causing white pine blister rust has led to the tree being listed as a federal species at risk. A disease screening program relies on carefully selecting potentially resistant parent trees, followed by testing their respective progenies. Beginning in 2011, trees were selected for controlled inoculations and field trials of seedling families. The performance of each seedling family indicates the level of disease susceptibility, implying genetic resistance in the parents. To date, we are screening hundreds of wild-collected parents. Based on post-inoculation assessments, almost one-third of our carefully selected parents have produced seedlings showing low susceptibility to disease. Numerous stakeholders are now beginning to plant disease resistant seedlings while also supporting the establishment of seed orchards and clone banks. Due to everchanging pathosystems, long-term diseasem screening will remain a critical contribution to the recovery of this valuable species.
The efficacy of pheromone-baited, standing subalpine fir Abies lasiocarpa (Hook) Nutt. and felled green trap trees was tested in southern British Columbia as potential manage- ment techniques for containing western balsam bark beetle Dryocoetes confusus Swaine populations prior to logging. In the year treatments were deployed, standing trees in close proximity to baited trees had significantly higher levels of current attack than those near felled trap trees or in control blocks. The control blocks had the lowest level of current at- tack. Diameters of attacked trees were significantly greater than unattacked trees in all treatments. Naturally attacked, standing subalpine fir had high levels of occupation (number of nuptial galleries) along the full length of the bole. Baited trees had similar levels of occupancy up to six metres in height. Felled green trees had lower occupancy than the baited or naturally attacked trees. Although baited trees concentrated attack into a discrete area, they did not artificially trigger an outbreak or further population expansion in the year following treatment. Felled trap trees appeared less attractive to western balsam bark beetle than natural, susceptible, standing subalpine fir; they are more difficult to de- ploy and therefore not recommended as a means of containing western balsam bark beetle prior to logging.
This study describes the impacts of 25 damaging agents recorded on young lodgepole pine trees over a 30-year period in a study plot in southern British Columbia. During the study, density fluctuated due to infill and mortality. Of the 1,295 stems per hectare present at the outset of the study, 37% of lodgepole pine died and only 24% of the trees remained pest-free by the final assessment. Pest-free trees were predominantly small and suppressed infill, leaving just over 1,000 stems per hectare of crop trees. Lodgepole pine terminal weevil affected over 38% of pine, with up to six attacks per tree. Fifty percent of lodgepole pine in the study was infected or killed by one or more hard pine stem rusts, with comandra blister rust and western gall rust being the predominant diseases, affecting 32% and 19% of the pine, respectively. Until age 20, 70% of weevil attacks caused major defects. From age 20–40 years, 50% of attacks caused major defects, often forks or multiple tops (stagheads). Defects were more severe when trees were attacked early in stand development. There was a strong correlation between the number of weevil attacks per tree and tree form, and the number of pests recorded per tree and tree form. Two or more pests per tree caused tree form to shift from good to moderate or poor.
In reviewing the genetic, morphological, behavioural, and ecological distinctiveness of caribou throughout Canada, the Committee on the Status of Endangered Wildlife in Canada (COSEWIC) (2011) divided “Southern Mountain caribou” (c.f. COSEWIC 2002) into three designatable units (DU) for conservation purposes: Northern Mountain (DU7), Central Mountain (DU8), and Southern Mountain (DU9) populations of woodland caribou. These new designations mean that each is considered a “wildlife species” according to the Species at Risk Act. Recent federal and provincial government reports refer to “Southern Mountain caribou,” conflating Southern Mountain, Central Mountain, and nine of the 45 subpopulations of Northern Mountain caribou into one pseudo-population, with clear conservation consequences. For example, in 2018, a federal decision on an emergency order required the Minister of Environment and Climate Change Canada (ECCC) to ascertain whether there were immediate threats to the survival or recovery of the Southern Mountain population of woodland caribou. By conflating two ecotypes and part of another into “Southern Mountain caribou”—an obsolete, geographical grouping not used since2002—ECCC’s assessment falsely informed the Minister that there were 3,764 “Southern Mountain caribou,” when in fact there were only 1,240 in the Southern Mountain (DU9)mpopulation. Other errors arising from the first distorted the number and trajectories of extant subpopulations. Instead of issuing the emergency order, the Minister entered into protracted negotiations with the province on recovery planning that continue at this writing. The nomenclatural ambiguity can be resolved by 1) using the currently accepted taxonomy naming Osborn’s caribou a valid subspecies, R. t. osborni, instead of Northern Mountain population of woodland caribou, 2) using original English names for Mountain caribou and Rocky Mountain caribou, and 3) basing conservation actions on these distinct phylogenetic units as per COSEWIC (2011, 2014).
Identifying and mapping suitable nesting habitat within coastal forests is a key element in the recovery and management of the Marbled Murrelet (Brachyramphus marmoratus), which is listed as Threatened in Canada. This article reviews the reliability and application of three primary methods used to assess habitat suitability: the BC Model, a GIS-based algorithm using Vegetation Resources Inventory (VRI); air photo interpretation (API), direct assessments from air photos based on forest structure; and low-level aerial surveys (LLAS), helicopter surveys assessing forest canopy structure and the presence of potential nest platforms. In general, LLAS provides the most reliable identification and is the only method of the three that estimates the occurrence of potential nest platforms in the forest canopy. The other two methods, API and the BC Model, are substantially less reliable in identifying habitat actually used by nesting murrelets. Spatial scale and survey intensity affect habitat classification using all three methods. Generally, fine-scale (~3 ha), high-intensity classifications with LLAS and API are more likely to detect suitable habitat at known nest sites than those using medium-scale (10s or 100s ha) and/or low-intensity classifications. Even with fine-scale high-intensity application, 15% and 25% of known nest sites were still classified as “unsuitable” habitat with LLAS and API, respectively. All three methods applied at the medium scale for mapping appeared to miss fine-scale nesting habitat (i.e., small numbers of suitable trees occurring in otherwise unsuitable habitat). Areas of mapped suitable habitat can therefore be adjusted to take this discrepancy into account, and methods to do this are discussed.
No single disturbance regime is suitable for maintaining ecological patterns and processes across an entire landscape when viewed broadly from an ecological perspective. Some species may require high-frequency and high-intensity disturbance, while others may require low-frequency and low-intensity disturbance. Across a large landscape, specific sites with certain features, slopes, and topography also provide important elements for the structure and function of the landscape. These sites, coupled with varying time since disturbance, provide diverse spatial mosaics across landscapes and are essential for biodiversity. Traditional land management has employed a simplistic view of natural processes. The result on large landscapes is that patterns derived from these processes are not comprehensively understood, accepted, or applied. In most landscapes, traditional management has not promoted heterogeneity so that all possible conditions are represented. However, based on all available evidence, creating heterogeneity and a shifting mosaic across the landscape should be a primary objective if conservation of biodiversity is the goal. This article introduces the concept of the landscape disturbance matrix (LDM) as a framework for strategic landscape planning that encompasses time since disturbance at multiple sites. This concept keys in on the needs of priority wildlife species, which have varying responses to time since disturbance. In this article, a large management area in northeastern British Columbia is used to demonstrate that managing change in the landscape for multiple times since disturbance on multiple sites will promote multi-functionality and biodiversity, thereby providing an objective basis for land management planning. A forward planning approach such as the LDM also provides a foundation for ecological resilience and disturbance-absorbent landscapes, thereby allowing land managers to plan for the future based on the past and current disturbance regimes.
Observing landscape patterns at various temporal and spatial scales is central to classifying and mapping ecosystems. Traditionally, ecosystem mapping is undertaken through a combination of fieldwork and aerial photography interpretation. These methods, however, are time-consuming, prone to subjectivity, and difficult to update. Light Detection and Ranging (LiDAR) is an advanced remote sensing technology that has rapidly increased in application in the past decade and has the potential to significantly increase and refine information content of ecosystem mapping, especially in the vertical dimension. LiDAR technology is therefore well-suited to providing detailed information on topography and vegetation structure and has considerable potential to be used for ecosystem classification and mapping. In this article, the potential to use LiDAR data to advance ecosystem mapping is examined. The current state of the science for using LiDAR data to classify and map key ecosystem attributes within an existing ecosystem mapping scheme is discussed by focusing on British Columbia Terrestrial Ecosystem Mapping and its associated Predictive Ecosystem Mapping. The article concludes by summarizing which components of ecosystem mapping and classification are best suited to the application of LiDAR data, followed by a discussion of the feasibility and future directions for mapping ecosystems with LiDAR technology.
The interior Western Screech-Owl (Megascops kennicottii macfarlanei) has been assessed as a species at risk. Regionally, survival rates are low, particularly during nesting. This study uses forward stepwise logistic regression to assess habitat selection at the tree, patch (150m2), and stand scales for twelve nests (the largest sample in any one region). At the patch scale, nest sites had more coniferous cover (33% versus 16%) than random. At the stand level, owls selected medium-age forests within an agricultural landscape, highlighting the need to conserve these habitats. While black cottonwood (Populus trichocarpa) and trembling aspen (P. tremuloides) are important nest tree species, riparian forests with coniferous cover, particularly western redcedar (Thuja plicata), may be more important for nesting in regional populations than previously realized.
A “zone of influence” is the difference between an anthropogenic activity’s spatial footprint and the extent of the activity’s effects on surrounding habitat and wildlife. This article reviews studies that have measured zones of influence for site-level activities that are relevant to oil and gas activities in British Columbia in order to inform the development of policies and procedures to manage their effects on terrestrial habitats and wildlife. Creation of edges, as well as noise and activity associated with industrial sites and roads, are the major stressors that generate zones of influence. These stressors create cascading effects that can result in altered ecosystems through a variety of mechanisms. Stressors can create abiotic and floristic effects that generally extend < 100 m into surrounding intact habitat, but effects on wildlife can extend up to 5 km and sometimes farther. Mitigating stressors at their source should reduce zones of influence and the need to apply management buffers to separate industrial activities from ecological resources.
Natural resource practitioners are increasingly making decisions that consider future climates. This article examines the regional patterns of change in temperature and precipitation within British Columbia. Based on a review of the literature, regionally specifictables are provided with examples of conservation-oriented adaptation actions to helpspecies and ecosystems adapt to future conditions.
Assessments were conducted at stream reaches associated with recent harvesting in the mid-coast of British Columbia to: 1) determine how riparian vegetation has been managed around coastal streams that do not typically require a riparian reserve, but contain potential habitat for tailed frogs, and 2) correlate harvest prescriptions with habitat quality. The results are intended to guide decisions related to harvesting around small fish-bearing, and all non-fish streams on the mid-coast of BC. We found that bedrock-dominated reaches exhibited less disturbance than erodible streams when subjected to riparian cutting but their confined channels may have facilitated the transfer of road debris downstream, creating blockages and dewatering. Tailed-frog tadpoles were observed where some riparian harvesting had occurred, but the channels were stable and stream flow undisturbed. Recommendations for best practices when planning to harvest around perennial coastal streams include the consideration of geologic site characteristics prior to making harvesting decisions.
Greenhouse gas emissions from cattle have been increasingly recognized as an important anthropogenic source. We investigated the impact of cattle ranching on these emissions in British Columbia in order to determine the overall carbon footprint. The grazing activity within the Lac du Bois grasslands of British Columbia was examined, with emphasis on identifying point sources and removals of greenhouse gas emissions from cattle ranching. Enteric methane emissions were empirically measured at two elevation gradients in the spring and fall of 2010. Cattle emitted on average 370 L CH4 per day; these measurements on native grasslands are comparable to work on tame pastures. A life cycle analysis was conducted with a validated HOLOS model based on empirical measurements. The following grassland improvement strategies were evaluated: reducing stocking density; and reseeding/interseeding grass and legumes with and without synthetic fertilizer additions. Reseeding was the most effective at reducing the carbon footprint of cattle ranching on the Lac du Bois grasslands. Reseeding initiatives could theoretically result in soil carbon sequestration rates of 2.12 Mg CO2 equivalent per hectare. A combination of reductions and removals should be implemented in the future to reduce the overall carbon footprint of cattle ranching in British Columbia.
