Maintain
total forest cover
Values
promoted
Forest cover is among the most defining
ecological characteristics of the Al-Pac FMA, occupying approximately
2.4 million ha or 41% of the study area. Maintaining forest cover
would promote the conservation of biodiversity by providing habitat
for forest-dependent species. It would also promote the conservation
of soil resources essential for the production of wood fibre;
soils also perform ecologically important roles in filtering and
moderating the flow of surface and groundwater, and cycling nutrients.
Additional ecosystem services include removal of air pollutants
and moderation of local weather. Since forests contain the majority
of the above-ground biomass and biotic carbon in the region, maintaining
forest cover would also promote carbon storage. The economic and
social benefits associated with forest cover are many. These flow
from forestry, hunting and trapping of forest wildlife, fishing,
recreational activities, and respect for cultural and spiritual
values, including those held by Aboriginal people (Anielski and
Wilson 2001).
Impacts
of land use
Deforestation is a globally important
problem with considerable local relevance, due to the dependence
of local communities on the employment and revenues associated
with wood production and the value of the ecological services
described above. Causes of deforestation in the study area include
forestry roads and landings, energy sector clearings (e.g., well
sites, pipelines, roads, seismic lines, surface mines), industrial
emissions, and forest clearing associated with agricultural expansion
and timber harvest just south of the study area. Climate change
poses an additional threat to forest cover, with increasing temperatures
and drier soil conditions predicted to cause a gradual replacement
of forested communities with grasslands (Bergeron and Flannigan
1995).
Indicator
trends
Forest cover in the study area has
declined by approximately 3% over the past several decades (Figure
8), having been replaced by industrial clearings associated with
both the forestry and energy sectors. Most (80%) of the industrial
footprint currently present in the region consists of linear developments
(e.g., roads, pipelines, seismic lines), with the remainder composed
of well sites, oil sands mines and cutblock landings (Figure 9).
Continued industrial expansion over the next several decades would
increase the industrial footprint by over 150%, to approximately
380,000 ha from the current 144,000 ha. Most of this increase
is expected to be associated with oil sands mines, pipelines and
roads (Figure 9). The net loss of forest cover during this period
is estimated to be approximately 4% (Figure 8). In this projection,
some features (e.g., major roads) are expected to last indefinitely,
while others (e.g., narrow seismic lines) are expected to be much
more short-lived.
Figure 8. Historical
and projected trends in forest cover
in the Al-Pac FMA.
Figure 9. Projected changes
in the industrial footprint in the Al-Pac FMA, 2000–50.
Light shading indicates area in 2000; dark shading represents
the additional area in 2050 under a moderate energy sector scenario
Maintain
the natural disturbance regime
Values
promoted
Natural disturbance is a defining
aspect of the boreal forest, and it has historically been the
strongest influence on vegetation structure and composition in
the study area. Forest fires and other natural processes such
as insect outbreaks, wind events and canopy gap dynamics have
strongly influenced forest biodiversity and ecological processes
at a range of spatial scales. A key characteristic of boreal natural
disturbance regimes is their variability; disturbances are highly
variable in size, frequency and intensity (Eberhart and Woodard
1987, Cumming 1997, Johnson et al. 1998, Stelfox and Wynes 1999).
Maintaining a natural disturbance regime within the region would
promote the conservation of species that require early successional
habitats and fire-created structures; these include woodpeckers
(Hobson and Schieck 1999), bark beetles and fire-dependent plants
such as fireweed. Natural disturbances also promote ecosystem
productivity by releasing nutrients contained in living vegetation
and returning it to the soil. Some nutrients are also subsequently
transported to nearby water bodies via surface and subsurface
flow. Also, while forest fires release biotic carbon during combustion,
much carbon remains in the form of tree boles that decompose slowly.
In addition, younger seral stages created by fire sequester carbon
at higher rates than the older stands they replace.
At the scale of individual forest stands,
forests disturbed by natural processes contain a wide range of
residual structures (Stelfox 1995, Lee and Crites 1999). For example,
post-fire stands typically retain most of the biomass present
prior to burning (Eberhardt and Woodard 1987). These residual
structures, in the form of standing dead trees, downed logs and
live trees that survive fire, provide habitat for numerous species.
Increasing the proportion of logged stands containing residual
structure thus would promote the conservation of biodiversity.
Impacts
of land use
Modern fire suppression and control
practices have been implemented in northeastern Alberta since
the 1960s (Murphy 1985), although the degree to which these activities
have successfully reduced the area burned is unclear (Cumming
1997, 2001). While the area burned may be smaller, many of the
areas that do burn are subject to salvage logging. Salvage logging
reduces the legacy of natural disturbance in the future forest
by removing standing dead trees used by species such as woodpeckers
and bark beetles (Lindenmayer et al. 2004).
Conventional (non-salvage) logging
also affects forest stands by removing much of the structure that
would otherwise remain after fire. In Alberta and elsewhere in
Canada’s boreal forest, clear-cutting is the primary logging
method. Al-Pac has introduced modified clear-cutting to increase
the retention of residual structure (Al-Pac 1999). On average,
approximately 5% of merchantable volume is retained in the primarily
deciduous stands logged by Al-Pac. While this represents a relatively
narrow range of variability compared with natural disturbance,
structured clear-cutting promotes the conservation of species
that depend on such structures. However, coniferous stands harvested
by quota holders generally contain little or no retained merchantable
volume.
Indicator
trends
Approximately 900,000 ha were burned
by fire in the Al-Pac FMA between 1970 and 2003 (Figure 10), an
average annual fire rate of around 0.5%, or 27,000 ha per year.
Historical records suggest that prior to 1950, fires were more
frequent (Andison 2003), burning at least 1% of the forest per
year. It is possible that fire suppression during the past few
decades has reduced the incidence of fire in the study area. Alternatively,
recent weather and fuel conditions may have been less conducive
to fire than several decades ago.
Figure 10. Distribution
of fires in and around the Al-Pac FMA, 1970–2003. Source:
Al-Pac
The extent of salvage logging in the
study area is variable, but during the past decade it is estimated
that approximately one-quarter of the merchantable forest that
burned was subsequently salvage-logged (D. Pope, pers. comm.).
A summary of salvage logging of stands burned in 1999 indicated
that there were plans to salvage log 56% of the merchantable forest
burned that year, although some of this area subsequently proved
to be unsalvageable (Al-Pac 2004). Factors affecting the extent
of salvage logging include road access and the recoverable volume
of wood remaining. Also, mature stands that contain a relatively
large volume of salvageable wood per hectare are more likely to
be salvaged than younger burned stands.
The future extent of salvage logging
(and thus of naturally disturbed areas) is difficult to predict
because the future extent of forest fire is uncertain. If fires
burn at a rate similar to before 1950 (1.25% per year, Andison
2003), then an average of 7,500 ha of forest would be salvage-logged
each year. This assumes that future rates of salvage logging remain
constant at 25%, which is probably conservative as an expanding
road network increases the proportion of burned areas that are
accessible. Because salvage logging is directed disproportionately
toward mature stands that contain relatively high wood volume,
the future supply of stands with a significant structural legacy
would be limited.
The future extent of conventional (i.e.,
non-salvage) logging is more predictable than that of salvage
logging. The area of conventionally logged stands in the study
area is currently approximately 250,000 ha (Figure 3). By the
year 2050, it is anticipated that an additional 500,000 ha will
have been harvested. If Al-Pac remains the only operator leaving
residual structure on its cutblocks, then approximately 30% of
all cutblocks (i.e., in conifer-dominated stands) will contain
little or no residual structure.
A related implication of future natural
disturbance is the difficulty of sustaining a constant supply
of wood fibre. Sustainable harvest levels in Canada’s boreal
forest generally do not factor in future losses associated with
fire, because the future incidence of forest fire is uncertain
(Armstrong et al. 1999). Instead, harvest levels are typically
recalculated after major fire losses occur. A timber supply analysis
for Al-Pac’s FMA, in which annual fire losses are considered,
suggests that current harvest levels (2.7 million m3 hardwood
and 2.0 million m3 softwood per year) would be difficult to sustain
for more than 40 to 60 years, after which significant shortages
in available hardwood and softwood fibre are projected (Figure
11). Shortfalls caused by fire losses would increase the reliance
of companies on salvage logging, further reducing the extent of
naturally disturbed areas.
Figure 11. Projected
trends in harvest volume to the year 2100 in the Al-Pac FMA under
three potential scenarios of fire frequency: low (0.83% per yr);
moderate (1.25% per yr); and high (2.5% per yr)
Maintain
old forest
Values
promoted
Old forest stands generally contain
the highest number of plant and animal species of all the successional
stages in the boreal forest. This is due to the diverse array
of habitat conditions that develop over time, including relatively
old, tall, large-diameter trees, standing dead and fallen trees,
diverse forest floor micro-topography (pit and mound), canopy
gaps created by fallen trees, and a wide range of tree ages and
sizes due to ongoing recruitment in canopy gaps (Stelfox 1995).
Many species reach their peak abundances in older seral stages
(Angelstam and Mikusinski 1994, Schieck et al. 1995, Kirk et al.
1996). Thus, maintaining old forest within the range of natural
variability would promote the conservation of species that require
such conditions. It would also promote the conservation of above-ground
carbon, as the volume of stored carbon tends to increase as stands
get older. Older forests are also valued for their high rates
of primary and secondary productivity, as well as for their aesthetic
appeal.
Impacts
of land use
Logging and fire are the primary causes
of a projected reduction in the area of older forest stands in
the study area. Logging, in particular, affects the area of older
forest because older stands are harvested before younger stands
(this enhances the long-term wood supply). The rate of wood production
peaks at around 70 years in hardwood-dominated stands, and 90
to 100 years in softwood-dominated stands.
Declines in the area of older stands
threaten the persistence of species that require these stands.
The effects of habitat loss on some species are compounded by
their negative response to fragmentation. For example, the density
of black-throated green warblers is lower in smaller forest patches
than larger ones (Schmiegelow unpubl. data).
Increased fire rates are predicted
to occur in this region due to global climate change (Bergeron
and Flannigan 1995, Bhatti et al. 2002), a trend that would further
threaten the supply of older forest stands.
Indicator
trends
Approximately 40% of the merchantable
forest in the study area, or 10% of the total area, is covered
by older forest stands (Figure 12). Historically, the area of
old forest in the region has probably fluctuated considerably
within a wide range of natural variability, and the amount at
any given time thus represents a “snapshot” of many
possible amounts. In an analysis of old forest supply in the Al-Pac
FMA, Andison (2003) estimated the “natural” range
of variability in older stands to be 8% to 33% of the land base.
Figure 12. Projected
trends in the area of old forest in the Al-Pac FMA under three
potential fire rates. (Fire rates as in Figure 11.)
Future logging activity in the study
area would reduce the supply of old forest considerably within
the next several decades (Figure 12). This is consistent with
a maximum sustained yield policy in which “over mature”
stands reduce the capacity of the land base to produce wood fibre
(Alberta Environmental Protection 1994a, 1996). By the end of
the first rotation (i.e., after several decades), old forests
would be restricted to merchantable stands ineligible for harvest
(e.g., riparian buffers, steep slopes) and non-merchantable stands.
The added effects of fire would accelerate this rate of loss (Figure
12), with the combined disturbances of logging and fire reducing
the future supply of old forest below the range of natural variability
within the next few decades. Since fires burn both merchantable
and non-merchantable stands, areas in which no logging takes place
cannot be expected to provide substantial areas of old forest,
particularly if fire rates increase due to climate change.
Maintain
key aquatic and hydrological features
Values
promoted
The boreal forest provides numerous
water-related services, including the recycling of water to the
atmosphere (via evaporation and evapotranspiration) and the filtration
of water as it flows over the ground surface and through the soil
(Thormann et al. 2004). Bodies of surface water such as wetlands,
lakes and streams provide habitat for many species, including
those that are truly aquatic (e.g., fish, loons) and those that
require aquatic habitat for part of their life history (e.g.,
frogs, beavers, pelicans).
A dominant aquatic influence in the
study area is the large area of wetlands. These are lands that
are saturated with water long enough to promote wetland or aquatic
processes as indicated by poorly drained soils, water-dependent
vegetation and various kinds of biological activity that is adapted
to a wet environment. A combination of environmental factors,
including flat topography, an abundance of poorly drained glacial
deposits and cool, humid climate have resulted in extensive wetland
areas throughout Alberta’s boreal forest (Vitt et al. 1996,
Thorman et al. 2004). In the study area, wetlands are the dominant
natural community type, covering just over half of the 6-million-ha
land base. Most wetlands in the region are peatlands (e.g., fens
and bogs), characterized by scattered, slow-growing stands of
black spruce and treeless habitats dominated by grasses, sedges
and mosses. Important ecological services provided by wetlands
include water filtration, storage and moderation of flow regimes,
carbon sequestration and wildlife habitat.
Reducing negative effects on water
quality and quantity, in addition to reducing the rate at which
wetlands are removed or degraded, would promote the conservation
of biological diversity, soil and water resources, and carbon
balance.
Impacts
of land use
Many wetlands and water bodies in northeastern
Alberta are fed by groundwater sources that may be sensitive to
industrial activities such as the pumping of groundwater down
in situ oil sands wells (Alberta Environment 2003) and the dewatering
of aquifers near oil sands mines (Griffiths and Woynillowicz 2003).
Roads may also disrupt water movement, leading to an impoundment
of surface water that alters the distribution of surface and subsurface
water (and associated plant communities) adjacent to the road
(Poff et al. 1997, Thormann et al. 2004). Finally, water withdrawals
from the Athabasca River in the oil sands area may lead to undesirably
low flows, particularly during the winter when natural flows are
frequently low.
Logging can temporarily alter local
hydrologic regimes by altering groundwater recharge–discharge
dynamics, the position of the water table and stream flow (Thormann
et al. 2004), although the effects of logging on hydrological
regimes appear to be similar to those of other disturbances such
as fire (Carignan et al. 2000, Prepas et al. 2001, 2003). Harvesting
of riparian vegetation can increase stream water temperature and
exposure to ultraviolet radiation, which may alter stream invertebrate
communities and contribute to increased algal growth (Thormann
et al. 2004).
Threats to water quality in the study
area include point-source pollution from the Al-Pac pulp mill
and other pulp mills located upstream on the Athabasca River.
Pulp mill residues are toxic to many aquatic and non-aquatic organisms
(including humans), and the decomposition of organic material
downstream of the mill during periods of low flow (i.e., winter)
may deplete oxygen to levels that threaten the survival of fish.
Contaminated water used during bitumen extraction from oil sands
may leak from tailings ponds. Historically, logging and road construction
have been shown to cause erosion and deposition of sediments into
watercourses. However, regulations have largely eliminated this
negative impact in most areas (Plamondon 1982 in Thormann et al.
2004).
Oil sands mining and to a lesser extent
peat mining are the major causes of wetland removal in the study
area. Because peat in wetlands accumulates very slowly, it is
essentially a non-renewable resource (Pembina Institute 2001).
In addition, the success of efforts to create wetland environments
on reclaimed mine sites is unproven.
The indirect effects of industrial
activity on wetlands (i.e., alteration of the hydrological regimes)
may be more significant than the direct losses of wetlands from
industrial clearing. As noted earlier, roads constructed through
wetlands may impede the flow of surface and subsurface water,
increasing the amount of accumulated surface water on one side
of a road, while reducing water availability on the other side.
This may turn may lead to plant mortality and habitat change adjacent
to the road (Poff et al. 1997, Thormann et al. 2004). Factors
influencing the type and severity of road effects on wetlands
include road location relative to surface flow patterns, the abundance
and size of culverts, and the porosity of materials used to construct
the roadbed.
Groundwater removal during in situ
oil production and dewatering of local aquifers during oil sands
mining may also disrupt wetlands that depend on groundwater recharge
(Griffiths and Woynillowicz 2003). An additional potential impact
is local contamination of wetlands from industrial spills and
mine tailings. Ground vegetation in wetlands may be particularly
sensitive to industrial emissions and acidic precipitation, an
impact that is probably restricted to the northern portion of
the study area where refineries and other emission-causing plants
are concentrated.
Indicator
trends
Approximately 3% of wetland cover
in the region has been converted to other land uses during the
past several decades (Figure 13). Over the next several decades,
it is estimated that an additional 4% of wetlands will be lost,
mainly due to oil sands mining (Figure 13). Trends associated
with the indirect effects of industrial activity on wetlands are
difficult to quantify, but continued expansion of the transportation
network in the region would potentially cause damage to extensive
areas of wetlands.
Figure 13. Historical
and projected trends in wetland area in the Al-Pac FMA under a
moderate energy sector development scenario
Recognize
and protect areas of traditional Aboriginal use and value
Values
promoted
This management objective is expected
to provide socio-economic as well as cultural benefits for Aboriginal
peoples while promoting conservation of natural capital throughout
the FMA.
Aboriginal peoples form a significant component of the population
living within the area of research. In fact, the entire Al-Pac
FMA is made up of lands that were extensively used by various
Aboriginal groups for many generations. For example, the Fort
McKay First Nations’ traditional lands in the northeastern
part of the FMA encompassed an area of approximately 38,000 km2
(Fort McKay First Nations 1994). The traditional territory of
the Bigstone Cree encompasses the western part of the Al-Pac FMA,
from Peerless Lake in the north to Calling Lake in the south.
Their traditional way of life was based largely on hunting, fishing,
trapping and gathering activities and continued until the 1960s
or 1970s, depending on the area. Respect for and stewardship of
the land were the foundations of their relationship with the forest.
Aboriginal people lived lightly on the land and “managed”
its products wisely. Protecting areas of traditional use and value
to Aboriginal people and involving them in land and resource management
decisions would help meet all of the conservation objectives identified
earlier.
Impacts
of land use
The development of conventional oil
and gas in the 1940s, of oil sands in the 1970s and of forestry
resources on a major scale in the 1990s has profoundly affected
the traditional way of life of the Aboriginal communities in the
Al-Pac FMA. Most of the biophysical impacts of land use discussed
above have directly affected the land and resources that Aboriginal
people relied upon for their livelihood. In many areas, land and
resource-based activities are now physically impossible (due,
for example, to clear-cutting) or have been negatively affected
due to the impact of resource extraction on wildlife populations
and on water quality and quantity. In the Fort McKay area for
instance, most people have stopped fishing in the Athabasca River
as a result of the deterioration of the fishery resources and
concerns over industrial pollution. Nevertheless, the connection
with the land remains strong and is culturally critical, and a
number of Aboriginal people still maintain an active “bush
life.”
Aboriginal communities started mapping
their traditional lands in the 1980s, with government and industry
funding. Traditional land use studies have now been completed
for several communities within the FMA. These studies identify
areas of traditional and current importance to bush economy users
for hunting, trapping, fishing and gathering, as well as for spiritual
and historical uses. They also illustrate the wealth of knowledge
that exists among Aboriginal people in connection with the land.
This knowledge is valuable for resource managers and developers,
and it may help to provide a better understanding of the impact
of industrial development on forest ecosystems and to develop
more sustainable approaches to land and resource use.
Establish
areas within the managed forest where human impacts are prohibited
or severely reduced
Values
promoted
Establishing additional protected
areas in the study area would promote the conservation of biological
diversity in various ways.
Contribution
to knowledge
Limited scientific understanding and
economic feasibility will always prevent resource managers from
conducting their business in a way that eliminates negative ecological
effects. Additional protected areas would help address this issue
by fostering improved knowledge of the effects of human activities
on regional flora and fauna. Indeed, several authorities argue
that protected areas, in which industrial activity is either prohibited
or severely restricted, are a critical element of sustainable
forest management (Environment Canada 1994, Senate Subcommittee
on the Boreal Forest 1999, NRTEE 2003b). By comparing ecological
conditions in protected (or benchmark) areas with those in the
rest of the landscape, researchers can gauge how far conservation
objectives have been achieved on the working landscape. Because
ecological conditions are geographically variable, many benchmark
areas dispersed throughout the working landscape would provide
more reliable comparisons than fewer benchmark areas, particularly
if they are not widely dispersed. Adequate representation of different
ecological zones is also considered an important criterion for
protected area selection (Kavanaugh and Iacobelli 1995).
Conservation
of biological diversity
Protected areas would promote the
conservation of biodiversity by providing refugia for species
and communities (such as older forest) that are sensitive to human
activities. They would also provide sources of individuals, seeds,
pollen and spores for introduction to the working landscape if
conservation efforts there are unsuccessful. As well, large protected
areas would foster the persistence of natural disturbance regimes
such as forest fire, and they would provide a buffer against shifting
environmental conditions associated with climate change. Corridors
in which only limited and sensitive land use is permitted may
also promote connectivity among protected areas and facilitate
movement of certain wildlife species (Harrison 1992).
Improved
market access for forestry companies
Forestry companies must demonstrate
that their tenures contain ecological protected areas in order
to achieve certain market certification standards, such as Forest
Stewardship Council (FSC) certification (FSC 2000). Because certification
provides an improved image in the international marketplace, establishing
protected areas potentially results in greater market access for
certified companies. Al-Pac is currently seeking FSC certification
(S. Dyer, pers. comm). In a previous Detailed Forest Management
Plan, Al-Pac proposed the protection of the Liege River watershed
in the northwestern part of the FMA (Al-Pac 1999). This would
have added an additional 140,000 ha of protected areas within
or adjacent to the FMA. This was viewed by Al-Pac as a strategy
to achieve its goal of sustaining all species within its FMA,
a goal that is consistent with provincial direction to maintain
species diversity (Alberta Environmental Protection 1998a).
Contribution
to traditional way of life
Finally, the establishment of more
protected areas would help meet the basic needs of Aboriginal
communities and preserve areas that are critical to their cultural
identity.
Impacts
of land use
A total of 96,000 ha (1.5%) of the
study area is designated as protected under provincial statutes
or forestry ground rule designations (e.g., buffer zones) (Figure
14). (Some types of industrial activity may be permitted in parts
of these areas.) The total area protected in the region would
increase to 4.7% if the three large protected areas bordering
the study area (Figure 14) were included in the total.
Figure 14. Map showing
the location of protected areas in and around Al-Pac’s FMA
in 2003. Source: Al-Pac
The Senate Subcommittee on the Boreal
Forest (1999) recommended that up to 20% of Canada’s boreal
forest be set aside as protected areas, including “areas
of old growth boreal forest, areas used traditionally for native
trapping, representative ecological areas and areas of significant
wildlife habitat.” Approximately 12% of the boreal forest
natural region in Alberta is protected, although over 90% of this
area is within Wood Buffalo National Park in the northern part
of the province. One outcome of the provincial Special Places
Program was to increase the level of protection of underrepresented
landforms and ecological sub-zones (termed natural history themes)
in Alberta to at least 2.75% of each natural history theme (Alberta
Environmental Protection 1998b). Schneider (2002) recommended
the addition of three large (500,000 ha) protected areas in and
near the Al-Pac FMA (Birch Mountains, Athabasca Rapids, Cold Lake)
plus a larger number of smaller protected areas to protect unique
landscape features such as sand dune complexes and highly productive
areas such as major river corridors.
An analysis of linear developments
in the boreal forest natural region of Alberta outside Wood Buffalo
National Park (Alberta Environmental Protection 1998b) concluded
that approximately 13% of the region was roadless. A subsequent
analysis of the Western Sedimentary Basin conducted by ForestWatch
Alberta suggested that most of the Al-Pac FMA was within 1 km
of an access corridor (including seismic lines) (Figure 15).
Figure 15. Density of
roads, seismic lines and other linear disturbances in Alberta
as of 1995–99. Source: Smith and Lee (2000)
Indicator
trends
Options for establishing additional
protected areas are declining within the Al-Pac FMA as resource
development activities continue to reduce the area of undisturbed
landscapes (see Figures 3 to 7). Establishment of protected areas
in undeveloped landscapes is further complicated by resource allocation
decisions that foster competition for land between industrial
users and those who want to promote protected areas. More than
80% of townships in the region contain one or more petroleum wells
(a surrogate for other industrial activity), with most of the
remaining 20% of townships under some form of resource tenure
(Cumming and Cartledge unpubl. data). Because there is currently
no requirement and little incentive to establish additional protected
areas in the Al-Pac FMA, the future area of protected land will
remain unchanged under the current management regime.
A major barrier to the establishment
of protected areas is that they would potentially constrain the
activities of the forestry and energy sectors. For example, removing
an additional 10% of merchantable forest from lands available
for timber harvest beyond the existing protected areas already
in place would contribute to shortfalls in softwood (but not hardwood)
supply (Figure 16). (This projection assumes future losses to
fire are minimal; fires are expected to exacerbate future fibre
shortfalls.)
Figure 16. Projected
trends in harvest volume under alternative levels of additional
protected area in the Al-Pac FMA. Low = 0%; moderate = 10%; high
= 20% reduction of merchantable forest area available for harvest.
Additional declines in wood availability associated with fire
are not included in these projections
Reduce
linear disturbance density and manage human access
Values
promoted
Roads and other linear developments
are thought to have many negative ecological effects (Reed et
al. 1996, Forman and Alexander 1998, Trombulak and Frissell 2000),
and reducing the rate of fragmentation by linear developments
in the Al-Pac FMA would promote the conservation of biological
diversity. Some wildlife species such as woodland caribou are
also sensitive to human disturbance along linear corridors, and
managing human access would help protect such species from further
population declines. Reducing the amount of forest cleared for
linear developments would also promote the conservation of above-ground
carbon, as well as promote economic values by reducing the rate
at which lands are removed from the forest-producing land base.
Reducing the disruption of surface and subsurface water flow (which
in turn would reduce the release of carbon to the atmosphere due
to decomposition and methanogenesis) would further promote the
conservation of above-ground and soil carbon.
Impacts
of land use
Arguably the most significant negative
effects of linear developments on biodiversity in the Al-Pac FMA
are associated with woodland caribou. Caribou habitat is degraded
by linear developments because caribou tend to avoid such features,
probably due to increased risk of predation by wolves (Curatolo
and Murphy 1986, James and Stuart-Smith 2000, Dyer et al. 2001).
The habitat quality of approximately 48% of core caribou range
in northern Alberta has been reduced due to proximity to linear
developments and other industrial features such as well sites
(Dzus 2001). Mortality of woodland caribou near roads and seismic
lines is likely increased due to poaching and native hunting (Dzus
2001).
Effects of linear developments on other
species are not as well documented, but preliminary evidence suggests
that the abundance of several neotropical birds may be reduced
in areas with high densities of linear developments (Schmeigelow
and Cumming unpubl. data). Related research suggests increased
nest predation on birds nesting adjacent to linear developments,
particularly wide pipeline rights-of-way (Anderson et al. 1977,
Fleming 2001). There is also some evidence that movement patterns
of selected mammal species, including flying squirrels and pine
marten, may be disrupted by linear developments (Marklevitz 2003).
Poorly constructed or maintained road
stream crossings can result in barriers to fish movements by creating
hanging culverts, velocity barriers or low-head dams (M. Sullivan,
pers. comm.). These barriers prevent fish from gaining access
to upstream spawning areas or re-colonizing large areas after
natural events such as droughts or winterkill. They may also isolate
and fragment populations, threatening the long-term viability
of sensitive species such as arctic grayling (Thormann et al.
2004). Roads, seismic lines and other linear developments that
facilitate motorized access are thought to increase fishing pressure,
particularly at watercourse crossings. Boreal fish populations
may be far more sensitive to increased fishing pressure due to
road access than to habitat change from logging and other forms
of land use (Post and Sullivan 2002).
Other ecological effects of roads in
particular include the disruption of surface water flow (Jones
et al. 2000), potentially leading to upstream wetting and downstream
drying, plus associated habitat change and release of biotic carbon.
Roads have historically caused erosion and increased flow of sediments
into streams, but this impact has been reduced by improved construction
and design standards.
Indicator
trends
There are currently over 100,000 km
of linear developments in the Al-Pac FMA. Two-thirds of these
features are seismic lines; the remainder are roads, pipelines
and transmission lines (Figure 17). This represents an average
density of 1.8 km/km2 over the entire FMA, although
linear development densities vary considerably among different
parts of the FMA (Figure 15).
Figure 17. Projected
trends in the length and composition of linear developments in
the Al-Pac FMA. Lines in top two graphs represent projected trends
under three scenarios of energy sector development (low, moderate,
high). In the bottom graph, light shading indicates length in
2000, dark shading represents the additional length in 2050 under
a moderate energy sector development scenario
If forestry activity persists at current
levels, and if the energy sector expands at expected rates (D.
Pope, pers. comm.), the average density of linear developments
in the Al-Pac FMA will increase to over 5 km/km2 (Figure
17). The forest sector requires additional haul roads and temporary
in-block roads; the energy sector requires additional roads, pipelines
and seismic lines.
The implications of this increase in
linear developments are perhaps most serious for woodland caribou.
Populations throughout northern Alberta have probably declined
in recent years (Dzus 2001), and recent research suggests some
negative demographic trends. Declines in habitat quality due to
avoidance of linear developments have been implicated as a major
cause of this trend. A habitat model developed by the Boreal Caribou
Committee suggests that habitat quality has declined by 23% over
the past 50 years, and that further declines are expected (Figure
18).
Figure 18. Historical
and projected trends in caribou habitat quality in the Al-Pac
FMA under a moderate energy sector development scenario. Values
below one represent demographic conditions that would result in
declining populations
As noted above, linear developments
may also cause fragmentation of streams. There are now approximately
2,500 stream crossings in the FMA, and the average length of stream
between hanging culvert crossings that obstruct fish movement
is 380 km. By 2030, the average length of stream between hanging
culverts would be 40 km, a level that would impede natural fish
movement and significantly increase the ease of human access to
the region’s stream network (Figure 19).
Figure 19. Projected
trends in watercourse fragmentation in the Al-Pac FMA, 2000-2100.
Lines represent projected trends under three energy sector development
scenarios (low, moderate, high)
Maintain
terrestrial carbon stocks and sinks
Values
promoted
Carbon storage is a critical
component of the global carbon cycle, which regulates the earth’s
climate. As such, carbon storage is one of the vital ecosystem
services provided by the boreal forest. The potential significance
of global climate change associated with increasing atmospheric
carbon has been well documented. In the boreal forest, most stored
carbon is below ground, with peatlands responsible for the accumulation
of large quantities of below-ground carbon due to slow decomposition
rates in cold, saturated soils. Reducing carbon emissions from
disturbed vegetation and soil would promote the conservation of
natural capital in the form of stored carbon.
Impacts
of land use
When forest vegetation is disturbed
or cleared (for timber, roads, plant sites, mines, well sites
or other uses), above-ground vegetation decomposes more quickly,
increasing the rate at which carbon dioxide is released into the
atmosphere. In addition, a dominant carbon sequestering agent
(trees) is removed. Forest harvesting, in particular, also results
in the conversion of older, carbon-rich stands to young stands
that contain less carbon, and it may also temporarily cause soil
saturation until vegetation becomes re-established. Saturated
soils and submerged vegetation impounded by roads passing through
wetlands may also release carbon through methanogenesis; wetland
areas deprived of historical water sources may release carbon
through organic decomposition.
Indicator
trends
Simulated projections suggest
that the amount of above-ground and below-ground carbon will decline
over the next 50 years by approximately 22 million t (Figure 20).
This trend would be accelerated by increased fire rates induced
by climate change.
Figure 20. Projected
trends in above-ground carbon in the Al-Pac FMA, 2000-2100. Lines
represent projected trends under three energy sector development
scenarios (low, moderate, high)
