Wildlife and habitat

Wildlife such as mammals, fish, birds and amphibians are ubiquitous across BC. Their habitats occupy ecological niches throughout the provinces many ecosystem types. Their study involves their ecology, sustainable management and conservation of multiple species. This includes understanding their behaviour, biology and environment.

Research Paper Introductions

A Visual Classification to Examine Tree Retention Patterns from Harvest Practices in Managed Northern Spotted Owl Habitat in British Columbia

The Northern Spotted Owl (Strix occidentalis caurina, hereafter Spotted Owl) is an old-forest–dependent raptor that requires large trees and snags for nest cavities or platforms and roosts (Chutter et al. 2004) (Figure 1). Structurally complex forests provide perches, cover for security and thermoregulation, and flyways for the owl, as well as a connected canopy for its arboreal squirrel prey. Snags provide dens for squirrels, and together with downed wood and shrubs, provide shelter and secure foraging habitat for other prey, including small mammals and passerine birds.

In British Columbia, Spotted Owl habitat on the southwest mainland is managed according to the Spotted Owl Management Plan (SOMP). Under the 1997 version of the plan (SOMP1), owl habitat management on the timber harvesting land base within the Chilliwack and Sea to Sky Natural Resource Districts was delivered through Long-Term Owl Habitat Area (LTOHA) and Forest Management Area (FMA) established within Long-term Owl Activity Centres.

A Review of Cougar Biology and Management in British Columbia - TR150

Cougars (Puma concolor) are the most widespread large carnivore in the Americas, and British Columbia is home to one of the largest and most intact populations of any jurisdiction. Cougars occur throughout most of the southern half of the province and are expanding their range northward. Based on an extrapolation using capable deer habitat and estimated cougar densities, the provincial population is estimated to be 5000–7000 animals. As a top carnivore, cougars play an important functional role in many ecosystems. As a big game species, cougars provide an important hunting opportunity for resident and non-resident hunters in British Columbia. Cougar conflicts with people are common in British Columbia and injuries to people, although far less common, have been increasing over the last century. However, this increase may be at least in part due to better recording. Human fatalities are extremely rare; the last human fatality caused by a cougar in British Columbia was in the 1990s. Cougars killed in conflicts with people have occasionally exceeded 160 animals in a year and the average is about 100.

Snow Interception in Response to Forest Stand Attributes on Mule Deer Winter Ranges in Dry-belt Douglas-fir Forests in the Central Interior of British Columbia - TR149

Snow depth has a critically important influence on mule deer distribution, habitat selection, energy costs, and population levels. Several factors, including forest structure, slope, aspect, elevation, and subregional climate, affect snow depth. Of these factors, forest structure is the only one directly affected by forest management activities such as harvesting, pre-commercial thinning, and road building. Partial cutting in uneven-aged Douglas-fir (Pseudotsuga menziesii) forests in the central interior of British Columbia has produced a range of stand structures. Snow depth and stand attribute data were collected in 1988–1991 from 11 stands with a range of harvest histories. There was a strong relationship between mean snow interception and mean stand attributes, including crown completeness and basal area. Frequency distributions were used to visualize variation in snowpack depth in each stand and help explain the meaning of this variation for deer.

Response by Wintering Mule Deer and Other Species to Low-volume Partial Cutting Every 30 Years in Interior Douglas-fir Forest in Central British Columbia - TR148

In the early 1980s, wildlife managers were concerned about the effects of traditional timber harvesting methods on the sustainability of mule deer (Odocoileus hemionus) populations in interior Douglas-fir (Pseudotsuga menziesii var. glauca) forests within the central interior of British Columbia. Research on habitat requirements and a low-volume, single-tree selection silvicultural system experiment at Knife Creek near Williams Lake, B.C. helped inform legal management requirements for mule deer winter range. In 2013–2014, 30 years after the first harvest entry at the Knife Creek site, the long-term effects of the original harvest were assessed using winter track counts, an index of relative habitat preference, on the original transects of the 1984–1991 study. A second harvest entry in the singletree selection system was conducted in 2014. Post-harvest winter track densities were measured from 2015 to 2019.

An Evaluation of the Accuracy of Licensed Wolf Harvest Data and the Correlation with Population Trends in British Columbia - TR137

We examined the British Columbia hunter survey data to see how accurately the kill was estimated by the various methods of recording kills and to test how well the kill data indexed changes in wolf abundance and distribution. All wolf kill data are inaccurate to some unknown extent and sampling methods would need to be changed to estimate the level of inaccuracy. Hunter and trapper kill data can be used to index large changes in wolf abundance and distribution across areas with large harvests. Use of harvest data to monitor population trend at finer scales (Wildlife Management Unit or Population Management Unit) would require improvements in harvest data collection. Hunter success and effort are not good proxies to index trends in wolf abundance due to uncertainty in hunter numbers and effort. We provide recommendations on how to improve the data

Long-term Effects of Pre-commercial Thinning on Winter Wildlife in Interior Douglas-fir Forests in Central British Columbia - TR133

Pre-commercial thinning is a silviculture tool used in interior Douglas-fir (Pseudotsuga menziesii var. glauca) forests in the Central Interior of British Columbia. However, little is known about the short- and long-term effects on habitat use by wildlife in the winter when pre-commercial thinning is applied to a highly dense layer of tree regeneration. On a research trial near 100 Mile House, B.C., track densities of common wildlife species were compared among three treatments and two time periods: Pre-commercial thin (PCT), Pre-commercial thin with uncut strips (PCT-strip), and uncut Controls immediately after treatment (1987–1989) and 28–30 years later (2014–2017). Wildlife track density was used as an index of relative preference of the stand treatments. Pre-commercial thinning did not affect relative use by mule deer (Odocoileus hemionus) immediately after thinning but appeared to be beneficial in the later period when mule deer use of the uncut Control blocks declined.

Research Options to Address Knowledge Gaps on Marbled Murrelet Terrestrial Habitat Requirements - TR130

This report identifies knowledge gaps on Marbled Murrelet (Brachyramphus marmoratus) terrestrial habitat requirements, and research options to address those gaps and facilitate the recovery of Marbled Murrelets breeding in British Columbia, as specified by the Marbled Murrelet Recovery Strategy (Environment Canada 2014) and the British Columbia government’s Implementation Plan for the species (BCMFLNRORD 2018). The report focusses on forest nesting habitat and considers marine foraging habitat only as it might apply to inland forest use and murrelet nesting behaviour. The report covers ongoing research, including how it may be expanded to address problems that have long limited reliable habitat identification and mapping. The report considers additional research needs, with particular attention given to new knowledge gaps such as future changes that are likely with climate change, and the application of new research and monitoring technologies.

Verification of a Marbled Murrelet Habitat Inventory in Three North Coast Landscape Units in Coastal British Columbia - TR117

To support Marbled Murrelet (Brachyramphus marmoratus) strategic planning initiatives in Central Coast and North Coast British Columbia, the Ministry of Environment had 1.5 million hectares of forest inventoried and mapped for potential nesting habitat quality using a six-class (Nil to Very High) air photo interpretation classification system. This classification evaluates attributes, such as tree size and canopy complexity, that are indirectly associated with potential nesting platform occurrence, on 1:10 000/1:15 000 air photos. We verified the habitat classifications of the air photo inventory (api) maps by using helicopter low-level aerial surveys (hereafter, aerial survey).

The Relationships Among Road Density, Habitat Quality, and Grizzly Bear Population Density in The Kettle-Granby Area Of British Columbia  - EN120

During the summer of 2015, we surveyed grizzly bears in the Kettle Granby grizzly bear population unit (gbpu) to help assess population status and map the distribution of bears within the unit. Our first objective was to estimate the current population abundance and density of grizzly bears and map their summer distribution. Our second objective was to investigate whether landscape conditions such as habitat quality and road density were related to bear abundance. Based on our results, we provide recommendations for improving the viability of the grizzly bear population in the Kettle Granby gbpu.

The grizzly population in the Kettle and Granby River valleys of southern British Columbia is considered threatened due to the low number of bears relative to the habitat suitability of the area, and because the population may be poorly connected with other grizzly populations (Figure 1). Grizzly bears are rare in the Okanagan Valley to the west and in Washington State to the east of the Kettle-Granby population, connectivity with the threatened South Selkirk population and the viable Valhalla population is likely poor due to the presence of the cities of Castlegar and Trail, and the Arrow Lakes farther north. We suspect population connectivity of the Kettle-Granby population to other grizzly bear populations is mainly to the north across Highway 6 in the Monashee Mountain Range

A Systematic Review of Stand-level Forest Management for Enhancing and Recruiting Spotted Owl Habitat in British Columbia - TR91

Habitat management for the endangered Northern Spotted Owl (Strix occidentalis caurina) was initiated in 1997 in British Columbia’s Chilliwack Natural Resource District and the Sea to Sky1 Natural Resource District under the Spotted Owl Management Plan (somp). This plan was revised in 2009. The 1997 plan is now commonly referred to as somp1; the newer 2009 revision is referred to as somp2. Under somp1, Spotted Owl habitat was managed on a stand-level basis within Spotted Owl Resource Management Zones, where operational guidelines for two forest-management approaches—light volume removal and heavy volume removal—were used. Under somp2, Spotted Owl habitat is managed as Long-Term Owl Habitat Area or as Managed Future Habitat Area. Best management practices and General Wildlife Measures within Wildlife Habitat Areas, designated under the Forest and Range Practices Act, describe two stand-level forest management approaches. Habitat enhancement practices are designed for application within the Long-Term Owl Habitat Area, and replace light volume removal (somp1). Harvest with retention replaced somp1 heavy volume removal and is applied within the Managed Future Habitat Area. Under somp, wetter and drier ecosystem types are managed slightly differently.

Results of Fungal Inoculation Treatments as a Habitat Enhancement Tool in the East Kootenay Region of British Columbia: 2007–2013 - EN112

Wildlife trees provide critical nesting, denning, roosting, and feeding habitat for more than 70 species of birds, mammals, and amphibians in British Columbia, including some species that are considered at risk provincially and federally. Depending on the age, condition, and disturbance type and history of the forested landscape, wildlife trees can be in short supply in some areas. This is the case in parts of the Columbia River valley in the East Kootenay region of British Columbia, where wildlife tree enhancement treatments using inoculation with native heart-rot decay fungi and mechanical stem modifications have been conducted since 2007 to increase local habitat supply. Thirteen properties in this region that are managed by several partners for ecosystem restoration, biological diversity conservation, and wildlife habitat maintenance or enhancement were selected for wildlife tree treatments using fungal inoculation between 2007 and 2013.

Understorey Vegetation Response following Restoration of Ingrown Ponderosa Pine and Douglas-Fir Stands in the East Kootenay Region - TR71

The response of understorey vegetation was monitored over a 7-year period following restoration of ingrown stands of ponderosa pine (Pinus ponderosa) and interior Douglas-fir (Pseudotsuga menziesii var. glauca) in the East Kootenay region of British Columbia. The restoration was based on a prescription of partial cutting and slashing in 1999 and 2000. The ponderosa pine site was also subjected to a prescribed fire in April 2004. At the ponderosa pine site, total herbaceous biomass doubled over a 6-year period on areas where treatments increased understorey light by 32–44%. Most of the forage increase was due to grass biomass, including pinegrass (Calamagrostis rubescens) and bunchgrasses. The forage response developed over time after an initial lag of 2–4 years and was most evident by years 5 and 6 following treatment. A regression model derived from 2006 herbaceous biomass/light relationships at the ponderosa pine site predicted that 80% canopy removal is required to achieve 50% of the forage potential for the site.

Using Low-level Aerial Surveys to Verify Air Photo Interpretation of Marbled Murrelet Nesting Habitat in Haida Gwaii - TR70

The response of understorey vegetation was monitored over a 7-year period following restoration of ingrown stands of ponderosa pine (Pinus ponderosa) and interior Douglas-fir (Pseudotsuga menziesii var. glauca) in the East Kootenay region of British Columbia. The restoration was based on a prescription of partial cutting and slashing in 1999 and 2000. The ponderosa pine site was also subjected to a prescribed fire in April 2004. At the ponderosa pine site, total herbaceous biomass doubled over a 6-year period on areas where treatments increased understorey light by 32-44%. Most of the forage increase was due to grass biomass, including pinegrass (Calamagrostis rubescens) and bunchgrasses. The forage response developed over time after an initial lag of 2-4 years and was most evident by years 5 and 6 following treatment. A regression model derived from 2006 herbaceous biomass/light relationships at the ponderosa pine site predicted that 80% canopy removal is required to achieve 50% of the forage potential for the site. Despite an increase in herbaceous biomass, the frequency of most plant species was not different on more open canopy areas compared to those with a relatively more closed canopy. This indicates that little colonization of unvegetated areas occurred during the study period. In fact, increases in the frequency of exposed mineral soil, especially following the prescribed fire, indicate that more unvegetated areas were created. The prescribed fire increased the frequency of exposed mineral soil by 40% and initially reduced the frequency of five important understorey plant species. At the Douglas-fir site, restoration treatments that created an average of 32% more understorey light increased total herbaceous biomass by 70% after 7 years.

Nest Structures and Habitats of the Northern Spotted Owl in Three Ecological Subregions of British Columbia - TR69

Fourteen nest sites of the endangered Northern Spotted Owl (Strix occidentalis caurina) in British Columbia were sampled in 2003 and 2004. Nests were located in three broad ecosystem types: the maritime (n = 1), submaritime (n = 6), and continental (n = 7) ecological subregions. Spotted Owls exhibited flexibility in their use of different types of nest structures across their broad ecological distribution. Most nests occurred in chimney top or side cavities of large diameter (average 98 cm dbh) trees and snags (79%) with fewer found on platform type structures (21%). Although a variety of tree species provided nest structures, the largest proportion were Douglas-fir (Pseudotsuga menziesii; 79%). There was little evidence that Spotted Owls selected for particular habitat attributes in the immediate area surrounding the nest (patch-level selectivity) within the nest stands, except for higher densities of small trees (< 10 cm dbh) and lower densities of mid-size snags (30-50 cm dbh). Older forest stands (> 140 years old) adjacent to the nest stand were defined as the local landscape. Stand-level selectivity within the local landscape was indicated because nest stands had significantly taller trees than adjacent stands. Nest stands were not uniformly distributed across available aspects (10-290°); most (92%) were on southerly and or eastern aspects, but the importance of aspect within the broader regional landscape is unknown. Findings from our study using a small sample of Northern Spotted Owl nest sites in British Columbia appear consistent with those from studies in the United States. The findings of our study support provisioning for nesting habitat over the long term, as undertaken in the current Spotted Owl Management Plan (SOMP2).

A Landscape-level Species Strategy for Forest Management in British Columbia: Exploration of Development and Implementation Issues - TR67

The landscape-level species strategy project was initiated in 2009 in support of the Chief Forester’s Future Forest Ecosystems Initiative. This scoping report explores the issues related to developing and implementing a landscape-level tree species strategy for forest management in British Columbia. It specifically aims to:

- identify the key elements of a landscape-level tree species strategy
- assess the implementation considerations for a landscape-level species strategy within the existing management framework
- develop an analysis methodology for portraying the landscape-level species composition and distribution for natural and managed stands

The main findings of this report are as follows:

- A landscape-level tree species strategy requires an understanding of the species biology and ecology baseline and processes; the interaction between species, climate change, and natural disturbances; the vulnerability of species and species complexes to changes in disturbance patterns and climate; and the influence of past management actions on landscape-level species patterns.
- The high level of uncertainty associated with how the climate will change and how forest ecosystems will respond over the next few decades requires a broadening of approaches to managing species at both the stand and landscape levels.
- An adaptive management framework for applying new species management approaches is required so that there is a feedback mechanism for evaluating how well the landscape-level species targets are being met or how they need to be adjusted.
- An analysis methodology for portraying tree species composition and density at a landscape-level scale was developed, and it indicated that the existing provincial data sets for mature natural stands and harvested stands provide results that are comparable with similar data sets at the regional scale.
- Effective approaches need to be developed to facilitate the successful implementation of landscape-level species strategies within our current management framework.

Group Selection Silvicultural Systems for High-elevation Forests (ESSFwc3) to Maintain Caribou Habitat in the Cariboo Region - TR64

The Mount Tom adaptive management trial was initiated in 1999 on 4067 hectares in mountain caribou (Rangifer tarandus caribou) winter habitat in east-central British Columbia. It builds on and expands knowledge gained from the Quesnel Highland Alternative Silvicultural Systems trial, set up further to the south in 1990, to explore options to maintain caribou habitat while allowing for some forest harvesting. The principal objective of the Mount Tom adaptive management trial is to examine the effects of applying group selection silvicultural systems and more specific treatments (e.g., opening size and site preparation), in a range of ecological and geographical contexts, at the operational level. The following topics are part of the trial: arboreal lichen abundance and species composition, stand development, stand stability, regeneration, understorey vegetation, snow accumulation and melt, microclimate, and operational harvesting. The size of the eight cutblocks (> 100 ha each) enables the forest company overseeing the project to realize economies of scale regarding layout, harvesting, and transportation, plus providing an opportunity to test different types of equipment. When the Mount Tom trial is fully developed, the treated and no-harvest control areas will be extensive enough to directly measure caribou use. The trial also provides an opportunity for other researchers to work on the site and for extension activities. The purpose of this establishment report is to document information about the study area, layout, and methods associated with the individual studies embedded in this long-term, complex trial.

Interpretation of Habitat Quality from Air Photos at Marbled Murrelet Nest Sites in Mussel Inlet on the British Columbia Central Coast - TR61

We used newer, larger-scale 2007 colour air photos to interpret habitat attributes and classify habitat quality of 14 Marbled Murrelet (Brachyramphus marmoratus) nest sites identified in 1992 (n = 2) and 1999 (n = 12) in Mussel Inlet on the Central Coast of British Columbia. Mussel Inlet is a fjordland environment atypical of other areas for which the air photo interpretation classification has been tested using nest sites (i.e., Haida Gwaii, Vancouver Island, and south coastal British Columbia). Nesting habitat described by 3-ha plots centred on the nest site was characterized in Mussel Inlet as having complex canopies with large trees in mid to low meso slope positions, and as such is comparable to that reported elsewhere in British Columbia. However, comparisons of the nest plot habitat attributes to those at 27 random plots also suggested that interpretations of murrelet habitat selectivity for Mussel Inlet differed from other coastal areas due to differences in characteristics and availability of forest structures. Overall in Mussel Inlet, more nest plots were classed as lower quality (i.e., 50% Low and Very Low) on air photos compared to other British Columbian studies (i.e., ~14% Low and Very Low). Although selectivity testing based on air photo habitat class was inconclusive, particularly for the High and Very High quality habitats for which limited habitat was available (~1 % of the study area), a trend was indicated for higher proportional use of Moderate and Low habitats and lower proportional use of Very Low habitats. We discuss limitations of the samples used for this study and issues in interpretation, resolution, and scale in applying the air photo methods in topographically complex, fjordland landscapes such as Mussel Inlet. Given these limitations and issues, we recommend use of aerial survey methods to confirm occurrence of nest platforms.

Verification of a Marbled Murrelet Habitat Inventory on the British Columbian Central Coast - TR60

To support Marbled Murrelet (Brachyramphus marmoratus) strategic planning initiatives in the Central Coast region of British Columbia, the Ministry of Environment had 1.5 million hectares of forest mapped for potential nesting habitat quality using a six-class (Nil to Very High) air photo interpretation classification system. This classification evaluates attributes, such as tree size and canopy complexity, that are indirectly associated with potential nesting platform occurrence, on 1:10 000/1:15 000 air photos. We verified the habitat classifications of the air photo inventory maps using helicopter low level aerial surveys. Aerial surveys are used to directly observe the forest canopy and classify it (Nil to Very High) for potential nest platforms and other Marbled Murrelet nesting attributes. If areas classed by aerial survey were of equal rank (in agreement) to those classed on the air photo map, then habitat classifications on the map would be considered reliable for planning purposes. If areas were classed differently by the two methods, an estimate of this difference could be used to correct the estimated total amounts of habitat per class on the air photo maps.

Validation of Modelled Habitat Classifications for the Northern Spotted Owl in British Columbia Using Patterns of Historical Occupancy - TR56

Large-scale, integrative decision support tools and models are often used to represent resource management problems and guide management policy. However, such tools and models can be difficult to validate and even more difficult to verify. This creates uncertainties in how best to use model results to inform development of management policy. We used a historical data set of detections of the endangered Northern Spotted Owl (Strix occidentalis caurina) in British Columbia to examine the degree of correspondence between projections of quantity of suitable habitat and its configuration as generated by a spatially explicit modelling framework, and broad classes of area occupancy by owls observed in detection surveys between 1992 and 2001.

Ecosystem and Tree Attributes Affecting the Presence of Functional Wildlife Tree Types - TR51

Wildlife Trees play a significant role in maintaining species richness in forested ecosystems by providing critical habitat. This study was completed to develop a better understanding of the relationship between ecosystem and tree attributes and an established functional Wildlife Tree type classification. Data from four studies conducted in different ecosystems in central British Columbia are compared in this paper. The four study areas were: (1) boreal aspen forests, (2) mixed conifer forests in the boreal foothills, (3) mixed conifer forests in the moist interior plateau, and (4) mixed conifer forests in the interior wet belt. In each study area, tree species were evaluated by diameter classes for the percentage of live versus dead stems and functional Wildlife Tree types based on an existing classification system, and results within and among study areas were then compared. The combined tree sample size totalled almost 19 300 stems, comprising 10 different tree species. To provide a link to provincial Wildlife Tree policy, each tree’s value was ranked using guidelines established by the provincial Wildlife Tree Committee. 

Management Strategy for Mule Deer Winter Ranges in the Cariboo-Chilcotin Part 1a: Management Plan for Shallow and Moderate Snowpack Zones - LMH60

This document represents one part of a three-part package for planning timber harvesting on individual mule deer winter ranges in the shallow and moderate snowpack zones within the Cariboo-Chilcotin, British Columbia.

This Management Plan specifies long-term stand-level objectives for winter range management, including:
- harvesting to a basal area objective;
- managing at a minimum 30-year cutting cycle;
- harvesting within an opening size objective,
- designing skid trails to occupy a minimum percentage of cutblock area;
- promoting a clumpy stem distribution;
- promoting Douglas-fir at all phases of management; and
- harvesting in relation to micro-topography.

Harvesting opportunities in the transition period (1996-2026) are increased in comparison to the previous direction provided in the Mule Deer Strategy (1996).

Harvesting Opportunity Types are described in detail, including:
1. harvesting trees currently attacked by Douglas-fir bark beetle;
2. harvesting non-Douglas-fir trees in stands with <40% Douglas-fir;
3. harvesting non-Douglas-fir trees in stands with 40% or greater Douglas-fir;
4. commercial thinning-from-below;
5. single-tree selection system designed for mule deer winter habitat;
6. harvesting on wetter sites; and
7. harvesting on cool-aspect portions of specific winter ranges.

Management Strategy for Mule Deer Winter Ranges in the Cariboo-Chilcotin Part 1b: Management Plan for Transition and Deep Snowpack Zones - LMH59

This document is Part 1b of a set of information required for planning timber harvesting on individual mule deer winter ranges in the transition and deep snowpack zones within the Cariboo-Chilcotin, British Columbia. This plan sets out standlevel objectives and strategies for these winter ranges. The second set of information, the long-term spatial objectives maps for each winter range, is briefly described here but will be accessed through a Web site documented in this report.

This plan provides objectives and strategies for managing winter range habitat, including:

- road access planning and management;
- stand age structure for the stand mosaic created by group selection;
- tree species composition for winter range stands;
- size and distribution of harvest openings within the context of a group selection silviculture system; and
- spatial planning of group selection harvest treatments.

This plan has been developed following years of research and consultation. The objectives and strategies presented are compatible with the Cariboo-
Chilcotin Land Use Plan (CCLUP) and forest management directions, including the CCLUP Integration Report (1998) and the Identified Wildlife Management
Strategy (1999). The winter ranges boundaries were legally designated in 2004 under Government Action Regulations, and General Wildlife Measures for mule deer winter ranges are being prepared based on this report.

A Framework to Support Landscape Analyses of Habitat Supply and Effects on Populations of Forest-dwelling Species: A Case Study Based on the Northern Spotted Owl - TR38

Planning tools and decision-making processes to support sustainable forestry are an integral part of practicing good forest stewardship in British Columbia. The challenges when applying stewardship principles are often at their greatest when resource extraction activities and habitats of forest-dependent species overlap. Tools to represent and integrate information about both ecological processes and predicted consequences of forest management activities, and approaches for comparing costs and benefits of both economic and environmental values, are evolving to meet this challenge. In this document we present a spatial modelling framework designed to assist those confronting these challenges to sustainable forestry. Users can use this framework as a tool to evaluate hypotheses about the ecological and economic consequences of management strategies. Of particular interest is the capability of the framework to assist in the search for acceptable trade-offs between social and ecological values—a necessary but challenging requirement of meeting good stewardship objectives in natural resource management. 

Community Structure of Forage Plants Consumed by Black Bears in the Nimpkish Valley, British Columbia - TR35

Coastal British Columbia is the focus of potential conflict between timber extraction and protection of forest components such as forage plants consumed
by black bears. To protect foraging habitat and to enhance forage plant abundance, researchers and managers must understand the habitat requirements of these forage plants.

We assessed the community structure of plants consumed by black bears in the Nimpkish Valley, British Columbia, with respect to environmental
gradients.

Non-metric multidimensional scaling (NMS) ordination revealed that variation in community structure of forage plants was related to soil nutrient and moisture content, elevation, and tree overstorey dominance. Of these three factors, soil nutrient and moisture content had the strongest relations to forage plant communities. Species richness of forage plants and abundance of invasive forage plants generally increased with increasing soil nutrient and moisture content and with decreasing tree overstorey dominance. In contrast to invasive forage plants, residual forage plants did not respond consistently to any of the three factors indicated by the ordination, although abundance of many residual forage plants was depressed where tree overstorey dominance was high.

To maintain the quality of black bear foraging habitat, forest managers should: (1) prioritize some forests with nutrient-rich and moist soils for protection; (2) ensure that these forested sites are distributed across the biogeoclimatic variants occupied by black bears; and (3) where harvesting occurs in these forested sites, avoid harvesting regimes that create large areas with a dense, structurally homogeneous tree cover.

Analysis of Presence/Absence Data When Absence is Uncertain (False Zeroes): An Example for the Northern Flying Squirrel Using SAS - EN74

Predicting species presence/absence, or other binomial responses from survey data, is common in wildlife and forestry research. In situations where a recorded absence may in fact represent a failure to detect what is actually there (a false zero) erroneous inferences may result with naïve application of procedures such as logistic regression (MacKenzie and Kendall 2002; Tyre et al. 2003; Wintle et al. 2004).

An example where this can be expected is in live-trapping studies of wildlife occurrence. With false zeroes, not only can the proportion of sites truly occupied be underestimated, but the relationship with explanatory variables (the predictive model, usually the aim of the exercise) may also be biased. Furthermore, the chances of a false zero may not be constant but rather a function of time or sample site characteristics, making comparisons among samples questionable.

Using sas® v9. we implemented the Zero-Inflated Binomial (zib) method of Tyre et al. (2003) that incorporates estimation of false zero rates. In addition we illustrate the use of Akaike’s Information Criterion (aic) to weight alternative models, and the use of the area under the curve (auc) of the Receiver Operating Characteristic curve (roc) for assessing model fit and prediction accuracy (Cumming 2000; Boyce et al. 2002). Our purpose is to show how to implement these methods using sas. We strongly recommend consulting the references for more thorough discussions of the theory, appropriate application, and limitations of the methods

Assessment of Silvicultural Systems Developed for Deep Snowpack, Mule Deer Winter Range in the Central Interior of British Columbia Regeneration and Vegetation Components - TR21

In the central interior of British Columbia (Southern Interior Forest Region), Douglas-fir (Pseudotsuga menziesii) tends to occur in even-aged stands in the Interior Cedar–Hemlock Moist, Cool, Horsefly biogeoclimatic variant (ICHmk3). Douglas-fir stands are important from both forest industry and wildlife habitat management perspectives. Mule deer require mature and older Douglas-fir stands as winter range. In these ecosystems, Douglas-fir stands are typically clearcut, thereby seriously compromising habitat value as winter range. This is a pilot study to examine the response of vegetation (percent cover) and Douglas-fir regeneration (density and growth) to a range of opening sizes, opening orientation (along and across contours), and site preparation treatment (yes or no), 5 years post-harvest. The openings (15 × 165 m [0.25 ha], 30 × 165 m [0.5 ha], 60 × 165 m [1.0 ha], 60 × 330 m and 140 × 140 m [2.0 ha]) are options for group selection, patch cut, or clearcut silvicultural systems. 

Windthrow in Partially Cut Lodgepole Pine Forests in West-Central British Columbia - EN70

The rate of windthrow was measured for 5.3 years post-harvest in partially cut lodgepole pine stands on the Chilcotin Plateau in west-central, B.C. There were no significant differences in rates between irregular group shelterwood, group selection and uncut treatments for live or dead trees. For live trees, rates were particularly low at 0.04 - 0.18% per ha per year therefore posing low risk from timber or forest health perspective. In contrast, rates were higher for dead trees at 1.4 - 2.3% per ha per year. Most of the dead trees were killed by mountain pine beetle in the early 1980's and in some stands this was up to 20% of the trees. The harvesting systems, designed to maintain northern caribou habitat as required by the Cariboo Chilcotin Land Use Plan, do not aggravate windthrow, but in light of the current mountain pine beetle epidemic, in areas reserved from harvest high levels of mortality eventual windthrow will be problematic for caribou.

Policy Implications of an Assessment of Long-Term Risks to Marbled Murrelet Populations in British Columbia  - EN66

The Marbled Murrelet (Brachyramphus marmoratus), a small seabird that nests in old forests of coastal British Columbia, is of international conservation concern. Beginning in 2001 the Canadian Marbled Murrelet Recovery Team undertook a three-part conservation assessment for the species. The assessment will form the basis of a revised national Marbled Murrelet Recovery Strategy and inform revisions to the provincial Identified Wildlife Management Strategy and land-use planning initiatives.

This note summarizes the risk assessment component (Part C; Steventon et al. 2003) of the conservation assessment. Our goal was to assess the effects of alternative broadscale forest management objectives (amounts, types, and sizes of coastal forest stands) on the relative probability of persistence of regional and coast-wide murrelet populations.

We used habitat-based population viability analysis in this assessment. Population viability analysis is a well known science-based means of projecting the cumulative effects of all the factors that affect populations, including uncertainty. Methods and results, described in detail by Steventon et al. (2003), were peer reviewed by three independent scientists.

Grizzly Bear Habitat in Managed Forests: Silviculture Treatments to Meet Habitat and Timber Objectives - EN54

In British Columbia, grizzly bears are considered to be a "vulnerable" species, and, in some parts of the province, grizzly bear populations are considered to be "threatened" (B.C. Ministry of Environment, Lands and Parks 1997). Rich valley bottoms in the Coastal Western Hemlock Zone are important grizzly bear habitat (MacHutchon et al. 1993). These areas are also valued for high timber productivity.

Grizzly bear food plants grow in abundance under the partially open canopy of primary forests in valley bottom sites (MacHutchon et al. 1993). In contrast, stands managed primarily for timber supply have little, if any, understory of value to grizzly bears (Alaback and Herman 1988). Silvicultural systems and treatments that supply food for bears throughout the stand rotation will help provide habitat while maintaining timber production.

The provincial government, through the Grizzly Bear Conservation Strategy (B.C. Ministry of Environment, Lands and Parks 1995) and the Identified Wildlife Management Strategy (B.C. Ministry of Environment, Lands and Parks 1999), is taking steps to conserve and manage grizzly bear habitat in critical areas.

Trials comparing silviculture treatments and stocking regimes that attempt to maintain or enhance grizzly bear forage supply in the Coastal Western Hemlock (CWH) biogeoclimatic zone began in 1992 (Johnson 1995). The goal of these projects has been to establish and maintain a commercially viable stand of trees, while managing for conditions conducive to the survival, growth, and productivity of grizzly bear forage throughout the rotation of the stand (Johnson and McLennan 2000).

Seral Stages across Forested Landscapes: Relationships to Biodiversity - EN18

Various plants and animals rely on different forest ecosystem "stages" to meet their habitat needs. Grizzly bears, for example, can range over hundreds of square kilometres in search of the food resources available in open and young forests before hibernating deep in mature forests. Some plant species can only develop on open, treeless, freshly disturbed sites, while certain canopy-dwelling insects spend their entire lifetime on the broad lichen- and moss-covered limbs of a single ancient spruce. During spring and summer, deer may sample tender herbs in clearcut areas, but, in severe winters, retreat several kilometres to protective old-growth stands.

Landscapes and the ecosystems that compose them "age" through time. The process of forest aging called "succession" transforms the composition of forested ecosystems as biotic communities respond to and modify their environment. Succession is an important topic in landscape ecology because of its significant effects on landscape diversity and the subsequent biological diversity and viability of various plant and animal populations.

The Forest Practices Code acknowledges the importance of landscape ecology concepts by enabling district managers to designate planning areas called landscape units, each with specific landscape unit objectives. The Biodiversity Guidebook (B.C. Ministry of Forests and B.C. Ministry of Environment, Lands and Parks 1995), a component of the Code, recommends procedures to maintain biodiversity at both the landscape and the stand level. This approach, which uses principles of ecosystem management tempered by social considerations, recognizes that the habitat needs of most forest and range organisms are met if a broad range of forest stand ages ("seral stages") are maintained across landscapes.

This extension note is the seventh in a series designed to raise awareness of landscape ecology concepts and to provide background for the ecologically based forest management approach recommended in the Biodiversity Guidebook. The focus here is on seral stages. We first define succession and seral stages. We then discuss the evolving views of ecosystem dynamics and succession theory, the role of disturbances in the current general model of forest development, and the influence of different seral stages on biodiversity. We conclude by suggesting how these concepts can be applied in landscape-level planning for biodiversity.

Biodiversity and Interior Habitats: The Need to Minimize Edge Effects - EN21

As forests are cut, edges are created. The environmental conditions produced along these edges may modify habitat values that are important to interior forest dwellers. Many landscape ecologists have voiced concern about this habitat disruption and about the potential loss of landscape-level biodiversity that may ensue if interior habitat ecosystems and processes are not sustained. Preserving sufficient interior habitat is therefore important to protect these species and maintain biodiversity.

The Forest Practices Code acknowledges the importance of landscape ecology concepts by enabling district managers to designate planning areas called "landscape units," each with specific landscape unit objectives. The Biodiversity Guidebook (B.C. Ministry of Forests and B.C. Ministry of Environment, Lands and Parks 1995), a component of the Code, recommends procedures to maintain biodiversity at both landscape and stand levels. These procedures, which use principles of ecosystem management tempered by social considerations, recognize that the habitat needs of most interior forest organisms can be maintained if excessive edge habitat is avoided and if forested areas are of adequate size to preserve interior habitat conditions.

This extension note is the sixth in a series designed to raise awareness of landscape ecology concepts and to provide background for the ecologically based forest management approach recommended in the Biodiversity Guidebook. The focus here is on the related topics of forest interior habitat and edge effects. We first define and differentiate between edge environments and forest interior habitats. Then we discuss several general ecological principles concerning edge environments and their effects on interior habitat and the plant and animal life that depends on it. We conclude by examining how excessive edge habitat might be prevented and forest interior habitat quality maintained at the landscape level.

Riparian Areas: Providing Landscape Habitat Diversity - EN17

Riparian areas represent less than 10% of the provincial land base, but are often considered the most dynamic of all landscape features. Natural disturbances and fluvial processes continually work together in these areas to create distinctive ecosystems that are crucial for biological habitat diversity. Because of their usually abundant supplies of water and nutrients, most riparian sites are highly productive for timber. Riparian ecosystems also exert a great influence over animal and plant life, and many wildlife species depend on riparian areas in some way for food, water, security, rest, travel, and reproduction.

However, because riparian areas usually occupy the lowest topographic positions in landscapes and have natural connections throughout the watershed, they are particularly sensitive. Many of the known negative effects of historical land-use practices on forested riparian areas resulted from a focus on the individual stand or stream reach. Resource managers now realize that a larger landscape perspective and longer timeframes are necessary when planning land-use activities in riparian zones.

The Forest Practices Code acknowledges the importance of landscape ecology concepts by enabling district managers to designate planning areas called landscape units, each with specific landscape unit objectives. The Biodiversity Guidebook (B.C. Ministry of Forests and B.C. Ministry of Environment, Lands and Parks 1995a), a component of the Code, recommends procedures to maintain biodiversity at both the landscape and the stand level. These procedures, which use principles of ecosystem management tempered by social considerations, recognize that the ecological processes of riparian habitats must be sustained to maintain landscape-level biodiversity.

This extension note is the fifth in a series designed to raise awareness of landscape ecology concepts and to provide background for the ecologically based forest management approach recommended in the Biodiversity Guidebook. The focus here is on riparian areas1. We first define and describe riparian areas. We then discuss several ecological principles underlying the common structural and functional characteristics of riparian areas and review their implications for biodiversity. We also briefly examine some of the functions of healthy riparian areas and cumulative harmful effects of poor management at the landscape level. We conclude by suggesting how these concepts can be applied in landscape- level planning for biodiversity.

Fall-down Rates of Subalpine Fir Snags at Sicamous Creek: Implications for Worker Safety and Habitat Supply - EN16

Current regulations require that all dead trees over 3 m tall are felled when an area is being logged (Workers' Compensation Board regulation 60.38). This clearly protects workers because tree-falling, especially hand-falling, is more dangerous when other trees, live or dead, could interfere with the falling tree. Snags must also be removed within 1.5 tree heights of work areas. This buffer is intended to decrease the risk that a worker in a block will be injured by a falling dead tree. However, there are several costs to snag-falling:
- Ecological damage. Many wildlife species require snags, including 35% of bird species and 30% of mammal species in British Columbia (Bunnell and Kremsater 1990). Different species require different stages of decay, from recently dead snags to soft stubs, and many species require canopy-sized snags. Many other, lesser-known species are linked to snags, including lichens (Goward and Arsenault 1997), fungi, and invertebrates in Sweden, 268 species of invertebrates are threatened or endangered due to loss of snags in managed forests (Berg et al. 1994).
- Worker hazard. Snag-falling is one of the most dangerous occupations in forestry. It is particularly dangerous in the 1.5 tree-height buffer Economic costs. Because their job is so dangerous, snag-fallers are well-paid, and the work cannot be done quickly. As a result, snag-falling costs are high ($670/ha in 1995 at the Sicamous Creek site). Also, snag-falling buffers around cutblocks can be large areas - a 10-ha cutblock, 400 x 250 m, requires snag-falling in 6.5 adjacent hectares if trees are 30 m tall.

Caribou Habitat Use in the Chelaslie River Migration Corridor and Recommendations for Management - LMH37

Movements and habitat use of radio-collared caribou (Rangifer tarandus) within the Chelaslie River “migration corridor” of the Tweedsmuir–Entiako herd were monitored from the spring of 1993 through the spring of 1995. The following conclusions were reached: 1. The area is more than simply a migration movement corridor. Even though on average it receives less winter use than the area south of Tetachuck Lake, in some years a significant number of animals winter in the area. 2. In the winter of 1993/94, when use was substantial, the caribou were most often associated with old forest on poor or low sites and with wetland/forest mosaics.

Breeding Bird Communities in Aspen Forests of the Sub-boreal Spruce (dk Subzone) in the Prince Rupert Forest Region - LMH33

A principal objective of this project was the study of the diversity of bird communities in different seral stages of the aspen ecosystem in the Sub-boreal Spruce (dk subzone) of the Prince Rupert Forest Region. In the spring of 1991 and 1992, I examined clearcuts (under 7 years), sapling aspen (7-23 years), mature aspen (50-60 years), old aspen with 100-year-old veterans, and mixed aspen-conifer stands. A preliminary survey of some conifer stands was also conducted. I counted birds over the 2 years using a modified point count method. One aspen stand was also examined by spot mapping.

Results showed a tendency for bird species richness, abundance, and diversity to all increase with increasing ecological age of the seral stage. Analysis of variance showed that differences in species numbers, bird abundance, and diversity between seral stages were significant for both breeding birds and total bird use. Numbers of breeding species, their abundance, and diversity indices were significantly lower in clearcuts than in sapling stands. Species abundance and diversity of breeding birds were greater in mixed aspen-conifer stands than in old and mature pure aspen combined. The number of breeding species in mixed stands was greater than that in pure aspen only in the second year of the study. Old aspen stands contained more birds and the species diversity was greater than in mature stands. The overall abundance of birds differed significantly between the 2 study years.

Analysis of the data using a Detrended Correspondence Analysis ordination procedure revealed that the bird communities in clearcuts and one of the three sapling stands were similar to each other, but quite different from those found in the other seral stages examined. The bird communities in the remaining stages were not distinct from each other, but rather there was an overlap from one bird community to another as the stands aged and the vegetation changed and became more complex. Habitat relations of the 16 most abundant species were analyzed by multiple regression. Results suggest that most changes in bird abundance were species specific, and relate to changes in the proportions of the different layers of vegetation in the seral stages.
Lack of sufficient information on habitat requirements precludes the assignment of a single management indicator species for each stage. However, species that could potentially be used for managing different seral stages, or habitat components therein, are proposed. The report suggests that removal of aspen, either commercially or by land clearing, might affect breeding birds using the different seral stages.

Handbook for Timber and Mule Deer Management Co-ordination on Winter Ranges in the Cariboo Forest Region - LMH13

Douglas-fir is an important component of the timber supply in the Cariboo Forest Region. A significant amount of the Douglas-fir is also an important component of mule deer winter range. This situation has led to resource allocation problems: Should trees growing on winter range be reserved for mule deer and the benefits that stem from wildlife management? Or, should the Douglas-fir be harvested for timber values? Are compromises possible? The B.C. Ministry of Forests and Ministry of Environment are working co-operatively to find ways to meet both timber and wildlife management objectives in the Cariboo Region. One part of this co-operative effort is a study of mule deer habitat relationships, funded by the Ministry of Forests and supported by the Ministry of Environment. This handbook is one important output from the study.

Barred Owl Removal Report 2007–2016 - TR128

A control program was implemented in British Columbia in 2007 to support recovery of the endangered Northern Spotted Owl (Strix occidentalis caurina) by removing Barred Owls (Strix varia), competitors that are contributing to the Northern Spotted Owl’s population decline. From 2007 to 2016, a 10-year period, 150 Barred Owls were removed from 32 sites that are managed for Northern Spotted Owls. Barred Owls were removed mostly by live capture and translocation to outside the Northern Spotted Owl range (soft removal, n=108), but lethal removal methods (n=42) were used if the Barred Owl imminently threatened a Northern Spotted Owl. Soft removal required 1.5 times more person-days per removal than lethal methods. Consistent inventory and removal efforts were undertaken at 19 of the 32 removal sites, and those sites were used to examine Barred Owl site-level response