Potential conflict between future development of natural resources and high-value wildlife habitats in boreal landscapes

The extent of conflict between developing resources and maintaining wildlife populations in the Muskwa-Kechika will vary depending on resource potentials in areas of high-value habitat and the ecology of different species. Contrary to our expectation, the proportions of high-value habitats of caribou and grizzly bears overlapping areas with high cumulative resource potential and resource potential diversity were not the highest among the seven species. Instead, across seasons, overlaps were consistently highest for moose followed by elk or wolves depending on season and the measure of multiple resource potential. Moose, elk, and wolves are habitat generalists whose occurrence across landscapes is more ubiquitous than that of the other four species we examined (Munõz-Fuentes et al. 2009; Stewart et al. 2010; Brodie et al. 2012). Consequently, broadly distributed high-value habitats of these three species increased the likelihood of their overlap with areas of high cumulative resource potential and high resource potential diversity.

Overlap between high-value habitats and measures of multiple resource potential can vary markedly between seasons, for caribou in particular. Caribou typically spend much of the growing season in high alpine areas, where the cumulative resource potential and resource potential diversity are relatively low because the potential for developing oil and gas and forest resources is low. For caribou that overwinter in lower elevation habitats (Seip 1992; Johnson et al. 2004; Gustine and Parker 2008), the potential for developing forest resources as well as oil and gas is higher than in alpine areas and is reflected in higher cumulative resource potential and resource potential diversity in their winter habitat. Similarly, the overlap between high-value habitat for grizzly bears and cumulative resource potential and resource potential diversity is greatest during the late-growing season when the bears use lower elevations than during spring in the Muskwa-Kechika (Milakovic et al. 2012).

Impacts of overlapping high-value habitat and exploitation of high resource potentials beyond the immediate short term are variable. Habitat alterations resulting in an increase in early seral communities can benefit species (e.g., moose, elk, wolves) that are also tolerant of some industrial development (James et al. 2004; Dunne and Quinn 2009; Houle et al. 2010; Webb et al. 2011; Van Dyke et al. 2012). In contrast, the large overlap between high-value winter habitat and areas of resource activity is of particular concern for the conservation of woodland caribou because as a species at risk (Committee on the Status of Endangered Wildlife in Canada 2011), it is highly sensitive to resource development. Caribou populations across Canada have drastically declined where resource development has occurred (Vors et al. 2007; Seip 2008; Sorensen et al. 2008; Boutin et al. 2012). Grizzly bears often are not adversely affected directly from resource development in the short term (McKay et al. 2014; McLellan 2015), but can be adversely affected by the increase in human presence and activities that result from long-term cumulative effects of resource development across broad landscapes (Apps et al. 2004; Linke et al. 2005; Ciarniello et al. 2007; McLellan 2015). Contrasting with wide-ranging species such as caribou and grizzly bears, Stone’s sheep and mountain goats show strong fidelity to small specific areas. Overlap with industrial activity in these critical parts of seasonal ranges would have substantive negative consequences even if, as we determined, there was not extensive overlap with their highest value habitats. Both species of high mountain ungulates are highly susceptible to overhead disturbance that may occur during any exploratory or extraction activities (Frid 2003; Côté et al. 2013).

In addition to the direct consequences that could result from developing cumulative resource potential and diversity in high-value habitats, access into the Muskwa-Kechika via roads to develop and extract resources would probably negatively affect all populations of large-mammal species over time. The proportion of high-value habitats overlapping areas with high potential for road development was greatest for moose, followed by elk or wolves depending on season. Mortality from hunting or other fatal encounters with humans tends to increase in populations of moose (Rempel et al. 1997), elk (Unsworth et al. 1993; McCorquodale et al. 2003), wolves (Person and Russell 2008), and grizzly bears (McLellan 2015) in response to improved road access for humans into remote areas. When road density is high, predation risk to caribou calves increases in disturbed landscapes (Dussault et al. 2006). Roads also affect movements of mountain sheep and goats to seasonal ranges, which may reduce gene flow and genetic diversity, and preclude access to traditional mineral licks (Epps et al. 2005; Poole et al. 2010).

At broad landscape scales over time, fragmentation of contiguous landscapes by industrial development into scattered early seral patches with long edge habitats could enhance populations of moose and elk (Irwin and Peek 1983; Schneider and Wasel 2000; Leclerc et al. 2012b) and consequently their primary predators, particularly wolves, in the Muskwa-Kechika (James et al. 2004; Sorensen et al. 2008). Caribou then could be subjected to higher predation pressure (Seip 1992). Moose have strong affinity to early seral forests and forest edges (Proulx and Kariz 2005; Leclerc et al. 2012b), whereas elk, also an early seral ungulate, tend to use more diverse habitats including open meadows and grasslands, as well as forest stands (Poole and Mowat 2005; Rumble and Gamo 2011). The relatively high forest resource potential that we observed in high-value habitats of these two ungulate species (as expected), indicates that their habitats in the Muskwa-Kechika could be altered from forest management activities. Forest harvesting creates early seral habitats dominated by graminoids and forbs, which increase in abundance for approximately 10 years and then gradually decline over the next ~30 years (Visscher and Merrill 2009). Populations of elk, with a preferred forage base of graminoid vegetation (Jenkins and Starkey 1993; Christianson and Creel 2007), would benefit initially. Moose, which forage primarily on shrubs (Stewart et al. 2010), would benefit most in approximately 10–15 years after harvest once shrubs began to increase (Potvin et al. 2005; Leclerc et al. 2012b). The gradual increase in shrub biomass over time would continue to support moose populations for 30–40 years following timber harvesting (Proulx and Kariz 2005; Leclerc et al. 2012b).

The overlap between high-value habitats of wolves and areas with high potential for forest resources as well as for oil and gas in the Muskwa-Kechika was consistently lower in proportion than those of their ungulate prey—moose and elk in the growing season and moose, elk and caribou in winter. Wolves tend to concentrate in forested landscapes fragmented with early seral habitat patches (Courbin et al. 2014) or naturally fragmented habitats with diverse vegetation types that increase the chances of encountering prey (Milakovic et al. 2011). The effects of industrial development, including oil and gas, forest resources, and wind power, on wolves appear to differ depending on type and density of industrial features and their associated human activity (Ehlers et al. 2014). Because wolves tend to avoid areas with high levels of human activity, presumably they would be displaced or forced to modify ranges and activity patterns if centers of development were established in the vicinity of currently occupied territories. On the other hand, wolves may benefit from sites of active development if some prey species, such as caribou, vacate disturbed areas and then concentrate in the periphery of developed areas in predictable patterns (Weir et al. 2007; Polfus et al. 2011). Moderate to high levels of high-value habitat of wolves in the Muskwa-Kechika overlapped areas with high resource potential for oil and gas, forest resources, and wind power; however, it is unlikely that wolf populations would be negatively affected directly from development activities of these resources, given there are thriving wolf populations on other landscapes heavily altered by industrial development (Schneider et al. 2010; Latham et al. 2011; Boutin et al. 2012).

Caribou are the ungulate species most likely to be affected by resource development and use in the Muskwa-Kechika. Large areas with high potential for forest resources, oil, and gas, as well as some areas with high potential for wind power coincided with high-value winter habitats. Areas with high mineral potential occurred more frequently in high-value growing habitats than winter habitats. These patterns suggest that oil and gas and forest resource activities could alter winter habitats at lower elevations. Development of wind power could affect caribou habitats across elevations, including wind-swept slopes in high-elevation wintering areas, and development for minerals would alter growing habitats in high-elevation alpine areas. Vulnerability of caribou to industrial development of oil and gas has been well documented. In Alaska, USA, expansion of oil fields and associated infrastructure and roads reduced the abundance of calving barren-ground caribou (R. t. groenlandicus) by 72 % (Joly et al. 2006). In Alberta, Canada, exploration and development for oil and gas have been a major contributing factor towards cumulative effects that are responsible for habitat loss and population declines of woodland caribou (Sorensen et al. 2008; Komers and Stanojevic 2013). Development activities can affect regular patterns of behavior and physiological conditions, increase movement rates and disrupt feeding cycles, increase energy expenditures and mass loss in winter, force caribou to alter traditional habitats, and decrease calf production and survival (Bradshaw et al. 1997, 1998). Consequently, caribou tend to avoid industrial features, especially when human activity levels are high (Dyer et al. 2001). Man-made linear corridors, including seismic lines, pipelines, roads and trails, often adversely affect caribou while benefitting wolves. These linear features facilitate access by wolves to otherwise inaccessible areas that historically served as natural refugia for caribou (James et al. 2004; Courbin et al. 2009; Latham et al. 2011), and increase predation rates (James and Stuart-Smith 2000), thereby contributing to population declines.

There are concerns relative to the conservation of lower elevation forests for wintering caribou because a large proportion of high-value winter habitats appears to overlap areas with high forest resource potential in the Muskwa-Kechika. Many woodland caribou (but not all; Gustine and Parker 2008) overwinter in large contiguous late-successional forests at lower elevation (Stronen et al. 2007; Hins et al. 2009). Alterations of these habitats would likely reduce biomass of ground and arboreal lichens, their primary winter forage (Seip 1998). In addition, habitat alterations are known to disrupt range fidelity (Faille et al. 2010) and reduce availability of winter refugia where caribou can segregate from predators and alternative prey (Seip 1992; James et al. 2004; Courbin et al. 2009). Caribou may be restricted to smaller remaining areas of suitable forest rather than spreading out at low density to avoid predators (Smith et al. 2000; Courtois et al. 2008; Lesmerises et al. 2013), or be forced to migrate long distances between late-successional forest blocks across a landscape with high predation risk (Johnson et al. 2002). Consequently, increases in predation rates, particularly by wolves (Dussault et al. 2012; Leclerc et al. 2012a, 2014), and reductions in survival rates often occur following extensive forest harvesting (Wittmer et al. 2007; Faille et al. 2010).

As with moose, elk, and wolves, the proportion of high-value habitat for caribou overlapping areas with high mineral potential was lower than for other resources. However, the overlap occurring in the growing habitat of caribou may pose a threat in high-elevation alpine areas because sensitivity of caribou to development activities is much higher than for moose, elk, or wolves. Relatively little has been documented regarding the effects of mining on woodland caribou, although it has been considered a threat to their conservation in northeast British Columbia (Muir and Booth 2012). In the Muskwa-Kechika, the potential for mining coal as well as metallic and industrial minerals coincided most with the high-value growing habitats of caribou. If resource extraction occurred, ground disturbance would directly reduce biomass of vascular plants and ground lichens in alpine and subalpine areas where many caribou spend their spring and summer. Caribou that overwinter on the windswept slopes of alpine areas also depend on ground lichens for their main source of winter forage (Seip 1998; Johnson et al. 2002, 2004). Recovery of this forage base would be slow (Smyth 1997). Because caribou tend to avoid mining sites by at least 2 km (Weir et al. 2007; Polfus et al. 2011), functional loss of habitat and reduction in forage available for caribou would be much greater than the losses attributed only to ground disturbed by mining.

Unlike the interactions among early seral ungulates (elk and moose), wolves, and caribou that are influenced strongly by changes in forest landscapes (cutblocks, oil and gas pads, and seismic lines), the high-value habitats of grizzly bears, Stone’s sheep, and mountain goats are more likely to be altered by development of minerals than other resources. We did not expect a high proportion of high-value habitat for grizzly bears to overlap areas with high mineral potential in the Muskwa-Kechika. Our analyses indicated that mining could alter habitats of grizzly bears across seasons, although somewhat smaller habitat alterations would result from development of oil and gas and forest resources, particularly in their late-growing habitats. Little is documented about the effects of surface mining on habitat use and populations of grizzly bears. Industrial activities may affect selection of den sites, as bears tend to avoid human activities, including industrial development, when selecting their dens (Linnell et al. 2000; Pigeon et al. 2014). Human activities <1 km away can cause some bears to abandon their dens and potentially increase cub mortality (Linnell et al. 2000). However, grizzly bears are adaptable to some changes in habitat conditions (Stewart et al. 2012). They may forage on older oil and gas well sites or in clearcuts with increased berry production, and development for oil, gas, and forest resources does not necessarily affect population size and other demographic features (McKay et al. 2014; McLellan 2015). Therefore, habitat alterations by industrial development, including mining, at fine spatial scales for individual projects may not have direct substantial adverse effects on populations of grizzly bears in the short term. Rather, the expansion of human activities and road access into remote areas across the Muskwa-Kechika over time, facilitated by mining as well as other industrial developments, would likely reduce bear numbers from hunting and bear-human conflicts (Ciarniello et al. 2007; McLellan 2015).

Not surprisingly, the high-value habitats of Stone’s sheep and mountain goats in the Muskwa-Kechika overlapped areas with high potential for minerals in greater proportions than those of other resources and other species. Responses of these two mountain ungulates to development of minerals or other resources are largely undocumented. Among wild sheep closely related to Stone’s sheep, Dall’s sheep (O. d. dalli) and bighorn sheep (O. canadensis) regularly used reclaimed coal mining sites (Elliott and McKendrick 1984; MacCullum and Geist 1992) and bighorn sheep also used an active copper mining site (Jansen et al. 2006, 2007) and mineral licks created by drilling for natural gas (Morgantini and Bruns 1988; Morgantini and Worbets 1988). Mining sites can offer various benefits to wild sheep. For example, removal of trees and shrubs creates open habitat with little vegetative obstruction, which may change wind patterns and reduce snow depth (MacCullum and Geist 1992). Presence of human activities, which lower predation risk, and proximity of mining sites to escape terrain appear to encourage the use of some mining sites by wild sheep (Elliott and McKendrick 1984). Furthermore, increases in graminoid vegetation in reclaimed industrial lands could provide wild sheep with preferred forage (MacCullum and Geist 1992) given their forage preference toward graminoids year round (Seip and Bunnell 1985; Walker et al. 2007). Difficulties of restoring shrub habitats in harsh environments (Smyth 1997; Jorgenson et al. 2010; Sloan and Jacobs 2013) might discourage mountain goats from using reclaimed lands, especially in winter when their dependence on woody forage increases (Adams and Bailey 1983; Fox and Smith 1988).

Landscape potentially considered for wind power development in northeast British Columbia occurs across elevations between 386 and 2114 m, but most frequently in mid elevations between 732 and 1250 m (Online Resource 5: Table S5.1; Fig. S5.2). Unexpectedly, our analyses determined that the greatest overlap across seasons between high-value habit and high wind power potential was for moose. The range of elevations and slope characteristics for high wind power potential most closely coincides with wintering habitats of moose in low-slope mid-elevation sparsely vegetated subalpine habitats (Gillingham and Parker 2008). As surmised, high-value habitats for caribou in winter (30 %) also occurred in areas with high wind potential. Gentle topography with space wide enough for wind power development coincides with habitats of caribou, particularly for individuals in low-slope high-elevation areas with low snow accumulation from constant exposure to wind (Johnson et al. 2004; Gustine and Parker 2008), for wintering elk that concentrate in large numbers on low-slope, lower-elevation areas with low snow accumulation (Gillingham and Parker 2008), and for wolves, which tend to occur in close proximity to their prey. Despite Stone’s sheep and mountain goats being associated with open high-elevation areas, there was very little overlap between their high-value habitats and areas with high potential for wind power. If new roads and power lines associated with wind power generation are also considered, however, overall effects of wind power development on all of these wildlife species would be greater than from development of wind towers alone (Kuvlesky et al. 2007).

We provided conservative assessments of conflict between areas of possible resource development and habitat conservation by restricting our analyses to distributions of only the high-value wildlife habitats and areas with high-resource potential. Using lower values of habitat suitability and/or resource potential would likely result in higher levels of conflict. Our assessments along with previous research (e.g., James et al. 2004; Seip 2008; Whittington et al. 2011; Beyer et al. 2013) lead us to conclude that resource development and the creation of networks of linear corridors such as roads, seismic lines, and pipelines in the Muskwa-Kechika may provide benefits to elk and moose through increases in early seral and/or edge habitats, and potentially to wolves through increases in these ungulates as prey. Caribou populations are likely to decline from losses of winter habitat (Smith et al. 2000; Courbin et al. 2009) and increases in predation by higher numbers of wolves that could result from higher numbers of elk and moose on disturbed landscapes (Serrouya et al. 2011; Boutin et al. 2012). Human activities and road access would likely reduce bear numbers (Ciarniello et al. 2007; Roever et al. 2008). Stone’s sheep and mountain goats would probably be most affected by aerial disturbance, and as with all of the focal species, by loss of prime habitats. Consequently, the large-mammal assemblage and their interactions on the landscape will change with resource exploration and development in the Muskwa-Kechika. We recommend creating plans for the Muskwa-Kechika that will maintain the present abundance and diversity of wildlife populations. Land management should (1) minimize loss and fragmentation of late-successional forests, (2) prevent early seral habitats from substantially increasing and spreading across the Muskwa-Kechika, (3) avoid or minimize development of resources and associated infrastructures including roads, trails, seismic lines, and other linear features in high-value habitats of caribou, and (4) prevent or minimize development of new road access into high-value habitats of grizzly bears and near traditional areas of Stone’s sheep and mountain goats.

The GIS approach used here identifies and visually displays areas that overlap for wildlife conservation and industrial resource potential across a large geographic area. Using these resource potential layers along with habitat suitability maps, land managers and conservation scientists can (1) proactively establish conservation and/or management plans that would minimize future conflicts between habitat conservation and resource development in undeveloped landscapes such as the Muskwa-Kechika, (2) effectively discuss whether high conflict areas for particular species should be protected or whether some level of resource development might be allowed, depending on the overall area of a species’ high-value habitat appropriated for conservation, and (3) simulate various scenarios on how resource development across space and time might affect the distribution and areas of high-value wildlife habitats or those of other land areas potentially designated for other purposes such as wilderness, outdoor recreation, or cultural heritage.

We have provided tangible baseline values of overlap between areas of resource potential and high-value wildlife habitats for a large landscape of almost intact wilderness. These baseline values also reveal probable conflicts between conservation of habitat and resource development, and are best applied in a framework of adaptive management—they should be continuously assessed and updated as new information becomes available. Having tangible baseline values makes it easier and more efficient to objectively compare and contrast new information to the baseline values and helps improve quality and validity of information incrementally over time. This process of assessment and discussion should encourage disclosure, sharing, and gathering of new information among scientists, resource managers, stakeholders, and the public. Our analyses provide a ‘heads up’ to those concerned with conservation of wildlife habitats and responsible resource management in the Muskwa-Kechika.