Search Results (11)

The Canadian boreal forest biome has been subjected to a long history of management for wood production. Here, we examined the cumulative impacts of logging on older forests in terms of area, distribution and patch configuration in the managed forest zones of the Eastern Canadian provinces of Ontario and Quebec. We also examined the consequences of these cumulative impacts on a once widely distributed and now threatened species, the woodland caribou (Rangifer tarandus caribou). The cumulative area of recently logged forest (since ~1976) was 14,024,619 ha, with 8,210,617 ha in Quebec and 5,814,002 ha in Ontario. The total area of older forests was 21,249,341 ha, with 11,840,474 ha in Quebec and 9,408,867 ha in Ontario. Patch statistics revealed that there were 1,085,822 older forests with core patches < 0.25 ha and an additional 603,052 < 1.0 ha. There were 52 > 10,00–50,000 ha and 8 < 50,000 ha. Older forest patches (critical caribou habitat) in the 21 local population ranges totalled 6,103,534 ha, distributed among ~387,102 patches with 362,933 < 10 ha and 14 > 50,000 ha. The median percentage of local population ranges that was disturbed was 53.5%, with Charlevoix having the maximum (90.3%) and Basse Côte-Nord the least (34.9%). Woodland caribou local population ranges with disturbed suitable habitats >35% are considered unable to support self-sustaining populations. We found that for the 21 caribou local population ranges examined, 3 were at very high risk (>75% area disturbed), 16 at high risk (>45 ≤ 75% area disturbed), and 2 at low risk (≤35% area disturbed). Major changes are needed in boreal forest management in Ontario and Quebec for it to be ecologically sustainable, including a greater emphasis on protection and restoration for older forests, and to lower the risks for caribou populations. Full article

Wildfires are a major natural disturbance in Canada that are postulated to increase under a warming climate. To derive accurate trends in burned area and to quantify the effects of fire frequency, duration, and extent, a sufficiently long time series of reliable burned area maps is required. With that in mind, we extended Canada’s National Burned Area Composite (NBAC) dataset from its previous start year (2004) back to 1986. NBAC consists of annual maps in polygon format where the area burned in each fire event is represented by the best available delineation among various mapping methods and data sources of varying quality. Ordered from more to less reliability, in the new 35-year time series (1986 to 2020), 10% of the total burned area was derived from airborne and high-resolution (<5 m) satellite imagery, 81% from change detection methods using 30 m Landsat satellite imagery, and the remaining 9% was largely from aerial surveys. Total (Canada-wide) annual burned area estimates ranged from 215,797 ha in 2020 to 6.7 million ha (Mha) in 1989. We computed 95% confidence intervals for the estimate of each year from 1986 to 2020 based on the accuracy and relative contribution in that year of the different data sources, for both the new NBAC time series and the polygon version of the Canadian National Fire Database (CNFDB), a commonly used source of spatially explicit data on burned area in Canada. NBAC confidence intervals were on average ±9.7% of the annual figure, about one-third the width of the confidence intervals derived for CNFDB. The NBAC time series also included nearly 5000 fire events (totalling 4 Mha, with the largest event being 120,661 ha in size) that are missing in the CNFDB. In a regional analysis for the Northwest Territories, retroactive fire mapping from Landsat imagery reduced historical estimates by 3 Mha (16%), which would result in a 1.6 Mha increase in the reported undisturbed critical habitat for threatened woodland caribou. The NBAC dataset is freely downloadable from the Canadian Wildland Fire Information System. Full article

Restoring anthropogenic footprints to pre-disturbance conditions or minimizing their long-term impacts is an important goal in conservation. Many footprints, particularly if left alone, have wide-ranging effects on biodiversity. In Canada, energy exploration footprints result in forest dissection and fragmentation contributing to declines in woodland caribou. Developing cost effective strategies to restore forests and thus conserving the woodland caribou habitat is a conservation priority. In this study, we compared the effects of wildfire and local variation in the amount of residual woody debris on natural regeneration in jack pine on exploratory well pads in Alberta’s boreal forest. Specifically, we investigated how footprint size, fire severity (overstory tree mortality), ground cover of fine and coarse woody debris, and adjacent stand characteristics (i.e., height, age, and cover), affected tree regeneration densities and height using negative binomial count and linear models (Gaussian), respectively. Regeneration density was 30% higher on exploratory well pads than adjacent forests, increased linearly with fire severity on the exploratory well pads (2.2% per 1% increase in fire severity), but non-linearly in adjacent forests (peaking at 51,000 stems/ha at 72% fire severity), and decreased with amount of woody debris on exploratory well pads (2.7% per 1% increase in woody debris cover). The height of regenerating trees on exploratory well pads decreased with fire severity (0.56 cm per 1% increase in fire severity) and was non-linearly related to coarse woody debris (peaking at 286 cm at 9.4% coarse woody debris cover). Heights of 3 and 5 m on exploratory well pads were predicted by 13- and 21-years post-fire, respectively. Our results demonstrate that wildfires can stimulate natural recovery of fire-adapted species, such as jack pine, on disturbances as large as exploratory well pads (500–1330 m²) and that the type and amount of woody debris affects these patterns. Full article

The Interior Wetbelt (IWB) of British Columbia, which includes the globally rare Inland Temperate Rainforest (ITR), contains primary forests poorly attributed and neglected in conservation planning. We evaluated the IWB and ITR using four IUCN Red List of Ecosystems Criteria: geographic distribution, environmental degradation (abiotic and biotic factors), and likelihood of ecosystem collapse. Clearcut logging (3.2M ha) represented 57% of all anthropogenic disturbances, reducing potential primary forest by 2.7 million ha (28%) for the IWB and 524,003 ha (39%) for the ITR. Decadal logging rates nearly doubled from 5.3% to 10.2% from 1970s–2000s. Core areas (buffered by 100-m from roads and developments) declined by 70% to 95% for the IWB and ITR, respectively. Vulnerable was assigned to karst, the only abiotic factor assessed, because it was associated with rare plants. For biotic factors, Old-Growth Birds were Vulnerable, Southern Woodland Caribou (Rangifer tarandus caribou) habitat and Sensitive Fish were Endangered, and Old-Growth Lichens habitat was Critical. Overall, the IWB was ranked as Endangered and the ITR as Critical with core area collapse possible within 9 to 18 years for the ITR, considered one of the world’s most imperiled temperate rainforests. Full article

When adopted, wildlife protection policies in Canadian forests typically cover large areas and affect multiple economic agents working in these landscapes. Such measures are likely to increase the costs of timber for forestry companies operating in the area, which may hinder their acceptance of the policies unless harvesting remains profitable. We propose a bi-level wildlife protection problem that accounts for the profit-maximizing behavior of forestry companies operating in an area subject to protection. We consider the regulator with a wildlife protection mandate and forestry companies licensed to harvest public forest lands. We depict the relationship between the regulator and forestry companies as a leader-follower Stackelberg game. The leader sets the protected area target for each license area and the followers adjust their strategies to maximize payoffs while meeting the protection target set by the leader. The leader’s objective is to maximize the area-wide protection of spatially contiguous habitat while accounting for the followers’ profit-maximizing behavior. We apply the approach to investigate habitat protection policies for woodland caribou in the Churchill range, Ontario, Canada. We compare the game-theoretic solutions with solutions that do not consider the forest companies’ objectives and also with solutions equalizing the revenue losses among the companies. Full article

Ground-dwelling macrolichens dominate the forest floor of mature upland pine stands in the boreal forest. Understanding patterns of lichen abundance, as well as environmental characteristics associated with lichen growth, is key to managing lichens as a forage resource for threatened woodland caribou (Rangifer tarandus caribou). The spectral signature of light-coloured lichen distinguishes it from green vegetation, potentially allowing for mapping of lichen abundance using multi-spectral imagery, while canopy structure measured from airborne laser scanning (ALS) of forest openings can indirectly map lichen habitat. Here, we test the use of high-resolution KOMPSAT (Korea Multi-Purpose Satellite-3) imagery (280 cm resolution) and forest structural characteristics derived from ALS to predict lichen biomass in an upland jack pine forest in Northeastern Alberta, Canada. We quantified in the field lichen abundance (cover and biomass) in mature jack pine stands across low, moderate, and high canopy cover. We then used generalized linear models to relate lichen abundance to spectral data from KOMPSAT and structural metrics from ALS. Model selection suggested that lichen abundance was best predicted by canopy cover (ALS points > 1.37 m) and to a lesser extent blue spectral data from KOMPSAT. Lichen biomass was low at plots with high canopy cover (98.96 g/m²), while almost doubling for plots with low canopy cover (186.30 g/m²). Overall the model fit predicting lichen biomass was good (R² c = 0.35), with maps predicting lichen biomass from spectral and structural data illustrating strong spatial variations. High-resolution mapping of ground lichen can provide information on lichen abundance that can be of value for management of forage resources for woodland caribou. We suggest that this approach could be used to map lichen biomass for other regions. Full article

Woodland caribou (Rangifer tarandus caribou) are reliant on Cladonia spp. ground lichens as a major component of their diet and lichen abundance could be an important indicator of habitat quality, particularly in winter. The boreal forest is typified by large, stand-replacing forest fires that consume ground lichens, which take decades to recover. The large spatial extent of caribou ranges and the mosaic of lichen availability created by fires make it challenging to track the abundance of ground lichens. Researchers have developed various techniques to map lichens across northern boreal and tundra landscapes, but it remains unclear which techniques are best suited for use in the continuous boreal forest, where many of the conflicts amongst caribou and human activities are most acute. In this study, we propose a two-stage regression modelling approach to map the abundance (biomass, kg/ha) of Cladonia spp. ground lichens in the boreal forest. Our study was conducted in Woodland Caribou Provincial Park, a wilderness-class protected area in northwestern Ontario, Canada. We used field sampling to characterize lichen abundance in 109 upland forest stands across the local time-since-fire continuum (2–119 years-since-fire). We then used generalized linear models to relate lichen presence and lichen abundance to forest structure, topographic and remote sensing attributes. Model selection indicated ground lichens were best predicted by ecosite, time-since-fire, and canopy closure. Lichen abundance was very low (<1000 kg/ha) across the time-since-fire continuum in upland forest stands with dense tree cover. Conversely, lichen abundance increased steadily across the time-since-fire continuum in upland forest stands with sparse tree cover, exceeding 3000 kg/ha in mature stands. We interpolated the best lichen presence and lichen abundance models to create spatial layers and combined them to generate a map that provides a reasonable estimation of lichen biomass (R² = 0.39) for our study area. We encourage researchers and managers to use our method as a basic framework to map the abundance of ground lichens across fire-prone, boreal caribou ranges. Mapping lichens will aid in the identification of suitable habitat and can be used in planning to ensure habitat is maintained in adequate supply in areas with multiple land-use objectives. We also encourage the use of lichen abundance maps to investigate questions that improve our understanding of caribou ecology. Full article

Seismic lines are linear forest clearings used for oil and gas exploration. The mechanical opening of forests for these narrow (3–10 meter) lines is believed to simplify microtopographic complexity and depress local topographic elevation. In treed peatlands, simplified microtopography limits tree regeneration by removing favourable microsites (hummocks) for tree recruitment and increasing the occurrence of flooding that reduces survival of tree seedlings. Little, however, has been done to quantify the microtopography of seismic lines and specifically the degree of alteration. Here, we measured microtopography at 102 treed peatland sites in northeast Alberta, Canada using a high precision hydrostatic altimeter (ZIPLEVEL PRO-2000) that measured variation in local topography of seismic lines and adjacent paired undisturbed forests. Sites were separated into four peatland ecosite types and the presence or absence of recent (<22 years) wildfires. Paired t-tests were used to compare microtopographic complexity and depression depth of seismic lines compared with adjacent forests. Microtopographic complexity on seismic lines was simplified by 20% compared to adjacent stands with no significant change between recently burned and unburned sites, nor between ecosites. Not only were seismic lines simplified, but they were also depressed in elevation by an average of 8 cm compared to adjacent forests with some minor variation between ecosites observed, but again not with recent wildfires. Thus, simplification of microtopographic complexity and the creation of depressions can persist decades after initial disturbance with some differences between peatland ecosites, implying the need for ecosite-specific restoration of topographic complexity. The importance of microtopography for tree regeneration on seismic lines remains an important question for reforestation of these disturbances and thus long-term recovery of habitat for species dependent on undisturbed peatlands, including woodland caribou. Full article

Pinus contorta-dominated montane forests of western Canada with relatively dense tree canopies have ground layers with abundant bryophytes, especially the feather mosses (Pleurozium schreberi and Hylocomium splendens), while those with more open canopies are dominated by species of reindeer lichens, especially Cladonia arbuscula s.l. and C. rangiferina s.l. Woodland caribou (Rangifer tarandus caribou), which are a threatened species in Alberta, prefer open, Cladonia-dominated forests for their winter food supply. This study investigated if opening the canopy by thinning mature montane forests of the Canadian Rocky Mountain foothills would change the abundance of lichens and bryophytes. In 1997, forests were thinned by removing 20%, 40%, and 60% by volume. In 2016, 19 years after treatment, we re-surveyed a subset of these plots (n = 97) for lichen and bryophyte abundance and species richness by utilizing the amount of canopy opening at the plot level as our prime gradient. We then used ordination to determine the relationship of control plots to treatment plots. In uncut forest, the control plots were highly variable, but were mostly dominated by feather mosses, with little or no bare ground. Feather moss abundance was lower in treatment plots when compared to control plots, while cover of bare ground was greater. Overall, 19 years after treatment, we found that, in treatment plots, lichen abundance remained stable or slightly increased, feather mosses decreased markedly, and unoccupied space was double that of the control plots. We conclude that the canopy opening had little effect on understory and ground layer diversity, but considering species abundance (1) bryophytes have not recovered after canopy opening, (2) populations of reindeer lichens increased marginally, but have not colonized areas left bare from bryophyte dieback, and (3), after 19 years there, remains unoccupied areas of bare ground in plots with a reduced canopy cover. Our study demonstrated that, with canopy cover reduction resulting from forest thinning operations, the ground layer diversity is maintained, but recovery of ground layers in old-growth pine-dominated forests is not promoted. Therefore, timber harvest that partially opens the tree canopy is unlikely to benefit caribou by augmenting or accelerating winter food availability and habitat suitability for caribou. Full article

Seismic lines are narrow linear (~3–8 m wide) forest clearings that are used for petroleum exploration in Alberta’s boreal forest. Many seismic lines have experienced poor tree regeneration since initial disturbance, with most failures occurring in treed peatlands that are used by the threatened woodland caribou (Rangifer tarandus caribou). Extensive networks of seismic lines, which often reach densities of 40 km/km², are thought to have contributed to declines in caribou. The reforestation of seismic lines is therefore a focus of conservation. Methods to reforest seismic lines are expensive (averaging $12,500 per km) with uncertainty of which seismic lines need which treatments, if any, resulting in inefficiencies in restoration actions. Here, we monitored the effectiveness of treatments on seismic lines as compared to untreated seismic lines and adjacent undisturbed reference stands for treed peatlands in northeast Alberta, Canada. Mechanical site preparation (mounding and ripping) increased tree density when compared to untreated lines, despite averaging 3.8-years since treatment (vs. 22 years since disturbance for untreated). Specifically, treated lines had, on average, 12,290 regenerating tree stems/ha, which is 1.6-times more than untreated lines (7680 stems/ha) and 1.5-times more than the adjacent undisturbed forest (8240 stems/ha). Using only mechanical site preparation, treated seismic lines consistently have more regenerating trees across all four ecosites, although the higher amounts of stems that were observed on treated poor fens are not significant when compared to untreated or adjacent undisturbed reference stands. Full article

In Canada, boreal woodland caribou (Rangifer tarandus caribou) are listed as “threatened” throughout their range due directly and indirectly to habitat loss. In western Alberta, in order to recover the Little Smoky boreal caribou population, the provincial government announced a plan to create a 100-km²-fenced enclosure that would encompass part of the caribou population range. Within the enclosure, all predators and other ungulate species will be killed. The fenced area will be dedicated entirely to the farming of caribou, with the intent of releasing weaned calves into adjacent areas with continued intensive wolf (Canis lupus) killing throughout the region. Industrial activities will be allowed to continue within the enclosure. In this review, we assess the government’s proposed program on the basis of questions related to the long-term recovery and sustainability of the caribou population, and the conservation and welfare of wildlife populations and individuals. We conclude that this program is unlikely to safeguard the future of this caribou population, will jeopardize wildlife communities inside and outside the fenced enclosure, and will cause harm to wild populations and individual animals. We recommend an alternative habitat conservation program which is ecologically justified over the long term, and invite the scientific community to object to the implementation of the government’s proposed Little Smoky caribou recovery program. Full article