Upload
others
View
2
Download
0
Embed Size (px)
Citation preview
Draft
Seismic lines in the boreal and arctic ecosystems of North
America: environmental impacts, challenges and opportunities
Journal: Environmental Reviews
Manuscript ID er-2017-0080.R1
Manuscript Type: Review
Date Submitted by the Author: 03-Feb-2018
Complete List of Authors: Dabros, Anna; Natural Resources Canada, Canadian Forest Service;
Natural Resources Canada, Northern Forestry Centre Pyper, Matthew; Fuse Consulting Ltd Castilla, Guillermo ; Natural Resources Canada, Northern Forestry Centre
Keyword: Linear disturbances, Low impact seismic lines, Conventional seismic lines, Environmental footprint, Regulations
https://mc06.manuscriptcentral.com/er-pubs
Environmental Reviews
Draft
1
Seismic lines in the boreal and arctic ecosystems of North America: environmental impacts, 1
challenges and opportunities 2
3
Anna Dabros, Matthew Pyper, and Guillermo Castilla 4
5
A. Dabros. Natural Resources Canada, Canadian Forest Service, 580 Booth Street, Ottawa, ON K1A 0E4, 6
Canada. 7
M. Pyper. Fuse Consulting Ltd., Spruce Grove, AB T7X 3S2, Canada. 8
G. Castilla. Natural Resources Canada, Canadian Forest Service, 5320 122 Street NW, Edmonton, AB T6H 9
3S5, Canada. 10
Corresponding author: Anna Dabros, Natural Resources Canada, Canadian Forest Service, 580 Booth 11
Street, Ottawa, ON K1A 0E4, Canada. Tel.: +1 343 292 8540 (e-mail: [email protected]). 12
13
14
15
Full word count with references: 16 702 16
Word count without references, figure captions and table: 11 977 17
18
19
20
21
Page 1 of 60
https://mc06.manuscriptcentral.com/er-pubs
Environmental Reviews
Draft
2
Abstract 22
The oil and gas industry has grown significantly throughout the boreal and arctic ecosystems of North 23
America. A major feature of the ecological footprint of oil and gas exploration is seismic lines - narrow 24
corridors used to transport and deploy geophysical survey equipment. These lines, which traverse 25
forests, tundra, uplands, and peatlands, were historically up to 10 m wide. Over the past decade, seismic 26
lines have decreased in width (in some cases down to 1.75 m – 3 m); however, their density has 27
increased drastically and their construction is expected to continue in regions of Canada and the United 28
States that are rich in oil and gas resources. We examine the literature related to the environmental 29
impacts of, and restoration and reclamation efforts associated with, seismic lines in the boreal and arctic 30
ecosystems of North America. With respect to conventional seismic lines, numerous studies report 31
significant and persistent environmental changes along these lines and slow recovery of vegetation that 32
translates into a lasting fragmentation of the landscape. This fragmentation has many ramifications for 33
biodiversity and ecosystem processes, including significant implications for threatened woodland 34
caribou herds. While modern, low impact seismic lines have comparatively lower ecological effects at 35
the site-level, their high density and associated potential edge effects suggest that their actual 36
environmental impact may be underestimated. Seismic line restoration is a critical aspect of future 37
integrated landscape management in hydrocarbon-rich regions of the boreal-arctic, and if widely 38
applied, has the potential to benefit a wide range of species and maintain or re-establish key ecosystem 39
services such as carbon sequestration and biodiversity. 40
41
Keywords 42
Linear disturbances, low impact seismic lines, conventional seismic lines, environmental footprint, 43
regulations, restoration methods 44
45
Page 2 of 60
https://mc06.manuscriptcentral.com/er-pubs
Environmental Reviews
Draft
3
1. Introduction 46
Seismic lines, narrow linear clearings created during hydrocarbon exploration, are a common 47
feature in the hydrocarbon-rich boreal and tundra ecosystems of North America (Fig. 1). As of 1999, 48
Timoney and Lee (2001) estimated that the total length of seismic lines in Alberta, Canada, alone was 49
1.5-1.8 million km, while Lee and Boutin (2006) noted that in northeastern Alberta, the mean density of 50
conventional seismic lines was estimated to be 1.5 km/km2, and in some regions was as high as 10 51
km/km2. Based on Landsat imagery from 2008-2010, seismic lines accounted for 46% of all linear 52
features across the Canadian boreal ecosystem (Pasher et al. 2013). In a more recent study conducted 53
across an area of 4022 km2 of boreal forest in western Canada, it was estimated that the total length of 54
seismic lines was five times the length of roads and rail lines (Pattison et al. 2016). 55
Seismic exploration aims at delineating underground reservoirs of oil and natural gas by 56
analyzing the reflection of sound waves from subsurface geological structures (EMR 2006). The seismic 57
waves are generated by drilling a series of shot holes 6 to 20 m deep along the seismic line and then 58
detonating explosives, or by truck-mounted surface vibrators (also known as vibroseis), which create 59
seismic waves by vibrating a heavy plate on the ground surface (EMR 2006; Severson-Baker 2006). The 60
speed of seismic waves travelling from these sources to the subsurface rock formations is recorded by 61
geophones placed along the same line (two-dimensional [2D] seismic lines), or in receiver lines 62
perpendicular to the source lines (three-dimensional [3D] seismic lines), which eventually results in data 63
that are used to identify oil and gas reservoirs and guide further exploration and drilling programs 64
(Severson-Baker 2006). A typical seismic program involves various phases: planning and design, 65
obtaining permits, clearing lines, surveying the land, drilling shot holes, laying out geophones, shooting 66
and recording, and clean-up and closure (Government of Northwest Territories 2012) 67
Construction of conventional seismic lines up until the end of the 20th century typically involved 68
clearing vegetation along 5 to 10 m wide lines using bulldozers. Conventional seismic lines were typically 69
Page 3 of 60
https://mc06.manuscriptcentral.com/er-pubs
Environmental Reviews
Draft
4
straight and spaced at distances of 300 to 500 m (Figs. 2a, 2b, 3a). These seismic lines then provided 70
access for machinery required to complete the seismic program (MacFarlane 2003; EMR 2006). The 71
adverse environmental impact of conventional techniques was recognized as early as 1960, when 72
seismic operations were performed in the summer, a process that often removed roots and the top 73
layer of the soil (Bliss and Wein 1972). This recognition led to the introduction of some of the first “best 74
practices” for seismic surveys (AECOM 2009), with seismic operations being shifted to winter months. 75
These operations still produced considerable soil disturbance, and the procedure was further modified 76
by the early 1970s through elevation of the blade, so that only tussock tops and hummocks were 77
removed, and later on by the addition of mushroom shoes to the blade, which further raised the blade 78
to avoid damage to vegetation and the ground surface (Bliss and Wein 1972). 79
Further technological improvements followed gradually, with development of low-impact 80
seismic (LIS) lines in the mid-1990s, by which time the lines were becoming narrower (approximately 81
5 m), although heavy machinery was still used in their construction (MacFarlane 2003). In Alberta, it was 82
recognized that cutting seismic lines was significantly affecting existing and potential timber resources; 83
as such, the provincial government instituted a compensation fee for timber damage when a seismic line 84
dissected productive forestland (Dunnigan 1988). Starting in the 1990s, the Alberta provincial 85
government offered a financial incentive for narrowing the lines, namely, a 50% rebate in the timber 86
damage fee, which was sufficient to prompt reductions in width from 7–8 m to as low as 2 m. Soon 87
after, several studies and reviews began to shed light on the significant environmental impacts of oil and 88
gas exploration on the boreal forest of western Canada (Dyer et al. 2001; Schneider 2002; Lee and 89
Boutin 2006). 90
In the early 2000s, 3D seismic programs—in which tightly spaced grids of seismic lines were 91
applied at distances of 50-100 m apart—resulted in seismic lines that were on average 2–4 m wide and 92
meandering. The seismic lines were created with low ground pressure mulchers (Figs. 1b, 1c, 2c, and 3c) 93
Page 4 of 60
https://mc06.manuscriptcentral.com/er-pubs
Environmental Reviews
Draft
5
or other lightweight equipment with mushroom shoes or smear blades (Figs. 3b1 and 3b2, respectively) 94
to minimize ground layer disturbance (MacFarlane 2003; CAPP 2004; EMR 2006). Currently, receiver LIS 95
lines can be as narrow as 1.5 m, and source LIS lines are usually no more than 5.5 m (EMR 2006). Under 96
sensitive environmental conditions, where lines less than 3 m wide are required, “envirodrills” (Fig. 3d) 97
mounted on all-terrain vehicles can be used to further reduce the impact (EMR 2006; Severson-Baker 98
2006). In British Columbia, Alberta, Saskatchewan, Northwest Territories, and Yukon, construction of LIS 99
lines is a preferred management practice for seismic exploration (EMR 2006; AECOM 2009; Government 100
of Northwest Territories 2012 ). 101
Within Canada, which is poised to become the world’s fourth largest oil producer (IEA 2016), the 102
majority of reserves (an estimated 168 billion barrels of recoverable bitumen) are found in three oil sand 103
areas in Alberta, which constitute 97% of Canada’s proven oil reserves (CAPP 2017). Production of 104
natural gas is also prominent across North America, with an estimated 1087 trillion cubic feet of natural 105
gas potential in Canada (CAPP 2017), and about 2355 trillion cubic feet of technically recoverable 106
resources of dry natural gas in the United States (US Energy Information Administration 2017). Much of 107
these reserves overlap with the boreal and arctic ecosystems of Canada and Alaska. Thus, it can be 108
expected that linear infrastructure for the exploration and development of these vast hydrocarbon 109
reserves will continue to expand. 110
Growing resource demands also continue to stimulate an expanding interest in industrial 111
exploitation of high-latitude environments, such as the arctic tundra, with implications for ecosystem 112
disturbance and restoration needs (Forbes and Jefferies 1999). Hydrocarbon exploration commenced in 113
the 1940s in Alaska (Emers et al. 1995; Jorgenson et al. 2010), in the 1950s in the high Arctic of the 114
Northwest Territories (Kevan et al. 1995), and in the 1960s in the low Arctic (Bliss and Wein 1972; 115
Kemper and Macdonald 2009a; Kearns et al. 2015). Severe surface damage from early seismic 116
exploration in the Arctic is still detectable after many decades (Kemper and Macdonald 2009a; 117
Page 5 of 60
https://mc06.manuscriptcentral.com/er-pubs
Environmental Reviews
Draft
6
Jorgenson et al. 2010). Although seismic exploration practices have changed substantially, leading to 118
overall reduction of negative effect on soil and plants (Bliss and Wein 1972; Jorgenson et al. 2010), 119
recovery of tundra vegetation after disturbance is often very slow (Forbes et al. 2001; Kearns et al. 120
2015). 121
This review provides an overview of the environmental impacts of seismic lines in boreal and 122
arctic ecosystems. We document scientific evidence of the effect that these lines may have on various 123
environmental factors (soil conditions, permafrost, hydrology, carbon storage and fluxes, snowmelt, and 124
edge effects), and of the responses that plants and fauna may have to these altered environmental 125
conditions. We compare the patterns of seismic line recovery across various ecosystems, ranging from 126
drier uplands to wetter lowlands, as well as between conventional lines, which may be many decades 127
old, and LIS lines, many of which have been constructed within the past decade. We also consider 128
human use of seismic lines post-exploration (e.g., for recreation). After reviewing the ecological impacts, 129
we discuss the current state of regulatory and restoration practices. Finally, we list some of the 130
challenges and opportunities that may shape future research aimed at developing new approaches to 131
benefit on-the-ground programs for the restoration of seismic lines. 132
2. Environmental and ecological effects 133
Significant and persistent environmental changes after seismic operations, along with slow 134
recovery of vegetation, have been noted in boreal and mixedwood transitional forest zones (Revel et al. 135
1984; MacFarlane 2003; Lee and Boutin 2006; van Rensen et al. 2015; Finnegan et al. 2018) and in 136
arctic zones (Forbes et al. 2001; Kemper and Macdonald 2009a, 2009b; Jorgenson et al. 2010; Kearns et 137
al. 2015). For example, many conventional seismic lines in the boreal ecosystems of northern Alberta 138
have shown little recovery over the past 30–40 years (Lee and Boutin 2006; van Rensen et al. 2015). 139
Likewise, the impact of seismic activities in arctic ecosystems is still conspicuous 20–30 years later 140
(Emers et al. 1995; Kemper and Macdonald 2009a; Jorgenson et al. 2010). Despite the perceived 141
Page 6 of 60
https://mc06.manuscriptcentral.com/er-pubs
Environmental Reviews
Draft
7
benefits of a reduced footprint with the advent of LIS line techniques (AECOM 2009), there is still 142
uncertainty about the impact of LIS lines in terms of ecosystem recovery (Kemper and Macdonald 143
2009b) and also in terms of the extent and magnitude of associated edge effects (Dabros et al. 2017). 144
The machinery and practices used for creating the seismic line, the time of the year when the 145
line is cleared, and the type and characteristics of the disturbed habitat all contribute to a complex 146
network of environmental changes. This, in turn, affects a wide range of microclimatic, hydrological, and 147
biogeochemical factors. The initial physical damage to the ground surface and the removal of vegetation 148
have far-reaching and persistent effects on these environmental factors, altering overall ecosystem 149
functioning and often hindering recovery (van Rensen et al. 2015). To better asses the recovery 150
potential of seismic lines, it is helpful to first explore the extent and magnitude of environmental 151
changes brought on by seismic lines. 152
2.1. Environmental factors 153
2.1.1. Soil and permafrost 154
Removal of vegetation reduces water intake and decreases evapotranspiration (Vitt et al. 1975). 155
This effect may contribute to higher soil moisture conditions on seismic lines than on the adjacent 156
forest, as was observed by Dabros et al. (2017). Furthermore, compression and compaction of the soil 157
by equipment used during line construction and subsequent seismic operations may lead to pooling of 158
water near the surface, since water cannot easily infiltrate soil that is densely compacted, especially if it 159
is a mineral soil (Arnup 2000). High moisture makes soils are more prone to compaction and changes in 160
soil structure, which further affects moisture and thermal regimes. All of these factors lead to reduced 161
productivity and potentially reduced chances of vegetation recovery. 162
The implications of soil compaction are especially relevant in permafrost regions, which cover 163
about half of the Canadian land mass and about a quarter of the land surface in the northern 164
hemisphere (Zhang et al. 2000; Smith 2011). Unlike the active layer of the soil, which freezes and thaws 165
Page 7 of 60
https://mc06.manuscriptcentral.com/er-pubs
Environmental Reviews
Draft
8
every year, the permafrost layer remains frozen year-round. This permanently frozen layer is sensitive to 166
human footprint such as seismic lines, which can alter the energy balance and hydrology of northern 167
regions if the permafrost is disturbed (Smith 2011; Williams et al. 2013). Since almost 100% of Canadian 168
landmass above latitude 55°N consists of either continuous, extensive discontinuous, or sporadic 169
permafrost (Smith 2011), any seismic program performed in the Canadian arctic and northern boreal is 170
likely to overlap with permafrost. 171
Seismic operations within permafrost regions can also result in rutting and subsidence of the 172
ground surface, changes in albedo and net radiation, and changes in ground thermal and moisture 173
regimes, which all contribute to permafrost thaw and damage (Felix and Raynolds 1989; Emers et al. 174
1995; Jorgenson et al. 2010; Williams and Quinton 2013; Braverman and Quinton 2016). In the Arctic 175
National Wildlife Refuge of northeastern Alaska, Emers et al. (1995) found that an increase in the depth 176
of the active layer and severe soil compaction on seismic lines led to increased soil moisture and 177
subsequent ponding, which was still evident a decade later. By 2010, more than two decades after 178
seismic operations had ended, frequent trail subsidence was still observed in that region, especially at 179
sites with greater soil ice content (Jorgenson et al. 2010). 180
Degradation of permafrost is compounded and exacerbated by the cumulative effects of 181
anthropogenic disturbances and climate change (Lawrence and Slater 2005). Global warming introduces 182
a layer of uncertainty connected to potential positive feedbacks, leading to even more pronounced 183
permafrost thaw and to the release of soil carbon through greenhouse gas emissions, especially CO2 and 184
CH4 (Christensen et al. 2004; Lawrence and Slater 2005; Zhang et al. 2008; Dorrepaal et al. 2009; Kurz et 185
al. 2013). Permafrost degradation has been projected to continue under changing climatic conditions 186
(Lawrence and Slater 2005; Zhang et al. 2008). Northern peatlands in particular, where much of the 187
permafrost is found, have accumulated large C stock over millennia, so the impact of permafrost 188
degradation is predicted to be large, long-lasting, and fueled by a positive feedback from carbon 189
Page 8 of 60
https://mc06.manuscriptcentral.com/er-pubs
Environmental Reviews
Draft
9
emissions that further contribute to global climate change (Dorrepaal et al. 2009). By exacerbating 190
permafrost degradation, seismic activities in the arctic region may directly contribute to this effect. 191
The exact causes of permafrost thaw resulting from seismic exploration are complex, stemming 192
from the interaction of numerous factors, including changes in vegetation and the physical and 193
thermodynamic properties of soil. Soil structure and soil moisture-holding capacity appear to be major 194
factors directly controlling the soil thermal regime, which in turn affects the physical state of the 195
permafrost (Haag and Bliss 1974; Guan et al. 2010). The high water-holding capacity of organic soils, 196
such as peat, makes them prone to maintaining high moisture and thus high thermal conductivity, which 197
in turn creates conditions favourable to permafrost thaw (Guan et al. 2010). Removal of vegetation 198
during seismic operations decreases soil evapotranspiration capacity, which, when compounded by soil 199
compaction and subsidence of the ground layer, leads to increased soil moisture, decreased latent heat 200
loss, increased soil heat flux and soil temperature, and increased permafrost thaw (Haag and Bliss 1974). 201
2.1.2. Hydrology and permafrost 202
Degradation of permafrost below seismic lines can also alter water storage and flow processes, 203
with implications for the water balance at local and regional scales (Williams et al. 2013). Permafrost 204
controls water storage, drainage, and connectivity in the surrounding wetland terrains, as well as 205
hydrological interactions between near-surface water resources above the permafrost and deep 206
groundwater below (Quinton et al. 2011). 207
In the Scotty Creek region of the Northwest Territories, linear disturbances have resulted in 208
substantial permafrost thaw under the black spruce-dominated plateaus that rise above the surrounding 209
tree-less and permafrost-free wetland (Williams and Quinton 2013; Williams et al. 2013). The wetter 210
conditions resulting from permafrost thaw can lead to tree canopy dieback, and in locations where the 211
summer thaw exceeds winter freezing, regeneration of these permafrost plateaus is unlikely (Williams 212
and Quinton 2013; Williams et al. 2013). Given the high density of winter roads and seismic lines in the 213
Page 9 of 60
https://mc06.manuscriptcentral.com/er-pubs
Environmental Reviews
Draft
10
Scotty Creek region (0.875 km/km2), these changes to treed permafrost plateaus induced by linear 214
disturbance have a critical effect on the basin hydrology of the whole region (Quinton et al. 2011; 215
Williams and Quinton 2013; Williams et al. 2013). 216
Modelling studies in Canada also have predicted the disappearance of permafrost and the 217
development of a layer of year-round unfrozen ground (a.k.a. talik) above the permafrost (Zhang et al. 218
2008). These predictions were recently confirmed when Braverman and Quinton (2016) found that 219
seismic lines at Scotty Creek contributed to the development of talik layers between the overlying 220
active layer and the underlying permafrost. Unlike the active layer, which freezes during the winter 221
months, talik can convey water as a conduit throughout the year, connecting bogs and fens that 222
previously formed separate entities (Braverman and Quinton 2016). Overall, the presence of seismic 223
lines in permafrost regions has a profound impact on belowground processes. Seismic lines affect soil 224
thermal regimes and regional hydrology, which on a local scale may contribute to unfavourable 225
conditions for plant recolonization, and at a global scale, cause permafrost thaw and release of carbon, 226
contributing to global warming. 227
2.1.3. Snow cover impacts on soil and vegetation 228
Frozen ground and deep protective snow cover have been reported to reduce the degree of soil 229
disturbance and damage to permafrost (Felix and Reynolds 1989), which is why seismic operations in the 230
Arctic (and elsewhere) are now performed mostly in the winter season, when the ground is frozen. 231
However, the legacy and impact of early arctic seismic programs can still be seen 20–30 years after 232
operations, regardless of the season in which they were undertaken (Kemper and Macdonald 2009a; 233
Jorgenson et al. 2010). Furthermore, studies of seismic operations that made use of recent technological 234
improvements such as lighter vehicles, suggest that 2–3 years after the operations are complete, the 235
effects on soils and vegetation are still pronounced and comparable to the degree of disturbance 236
inflicted by seismic operations in the Arctic several decades ago (Kemper and Macdonald 2009b). 237
Page 10 of 60
https://mc06.manuscriptcentral.com/er-pubs
Environmental Reviews
Draft
11
Therefore, the apparent benefits of performing seismic operations in the winter months, with the snow 238
acting as a protective buffer zone, are not always evident. 239
Within boreal and arctic ecosystems, snow cover can last longer on linear disturbances such as 240
seismic lines, partially because the ground surface affected by subsidence acts as a snow catchment 241
basin (Haag and Bliss 1974). Delayed snowmelt may, in turn, delay plant phenology. Such changes have 242
important implications for plant growth and succession, because they shorten the already short growing 243
season for plants at higher latitudes (Dabros 2008; Bjorkman et al. 2015). 244
2.1.4. Solar radiation, air temperature and wind velocity 245
Regardless of the seismic program location and technology used, removal of the vegetation 246
layer, or of the vegetation and top soil layers, along with the longer presence of the snow layer on 247
seismic lines, affects albedo and radiation absorbance of the surface. The amount of solar radiation 248
reaching the ground surface depends on the width of the line and the height of the adjacent canopy 249
(Williams and Quinton 2013); the line’s orientation (Revel et al. 1984; van Rensen et al. 2015); variations 250
in topography (Braverman and Quinton 2016); level of initial disturbance; and degree of recovery (Haag 251
and Bliss 1974; Williams and Quinton 2013). 252
In the summer, removal of vegetation on linear disturbances can decrease the albedo of the 253
ground surface (Haag and Bliss 1974), which can be expected to increase heat absorbance and soil heat 254
flux, thus inducing permafrost thaw. However, relative to the effect of potential changes in near-surface 255
soil moisture, increases in solar radiation do not appear to be a major factor controlling permafrost thaw 256
along linear disturbances (Williams and Quinton 2013). On the other hand, in winter and early spring, 257
the longer presence of snow on the line (Haag and Bliss 1974) likely results in the lines having a higher 258
albedo, in comparison to sites adjacent to the lines. 259
Solar radiation also affects the environmental conditions on a linear disturbance. For example, 260
Haag and Bliss (1974) found that air temperature was significantly lower and wind velocity was higher 261
Page 11 of 60
https://mc06.manuscriptcentral.com/er-pubs
Environmental Reviews
Draft
12
up to 50 cm above an arctic winter road as compared to control plots. The authors attributed these 262
trends to a thicker atmospheric boundary layer due to the subsidence of the winter road. Increased 263
wind velocity and temperature also have been observed on seismic lines (S. Nielsen, personal 264
communication 2017). 265
2.1.5. Carbon dynamics 266
Given current projections for global climate change (IPCC 2014), the environmental footprint of 267
linear disturbances such as seismic lines may lead to cumulative and perpetuating effects on the 268
resilience of northern ecosystems (Kemper and Macdonald 2009a). Because of slow decomposition due 269
to cold temperatures and an often anoxic environment, northern ecosystems have accumulated large 270
carbon stock over millennia. In particular, global warming and increasing occurrence of disturbances 271
could turn certain parts of the northern regions into significant carbon sources in the near future (Kurz 272
et al. 2013), creating a positive feedback and contributing to further climate warming. 273
The removal of vegetation on seismic lines affects carbon storage and cycling in boreal 274
ecosystems. Even though enhanced tree growth along seismic line edges (Bella 1986) can offset a 275
portion of the carbon lost through tree removal, the net carbon balance can still shift from a sink to a 276
source in boreal treed ecosystems (Kurz et al. 2013, Strack et al. 2017). There is also evidence that global 277
warming promotes the release of ancient peatland carbon in northern peatland ecosystems, which have 278
accumulated one-third of Earth’s soil carbon stock since the last Ice Age (Walker et al. 2016). Increased 279
respiration has been observed with a 1°C increase in temperature, especially in the presence of dwarf 280
shrubs and graminoids (Walker et al. 2016), which are often more abundant on recovering seismic lines 281
than in the adjacent undisturbed sites (Emers et al. 1995; Jorgenson et al. 2010; Finnegan et al. 2018). 282
Permafrost thaw associated with construction of seismic lines may also lead to a shift of the ecosystem 283
from sink to source through the release of carbon (Schuur et al. 2009). 284
Page 12 of 60
https://mc06.manuscriptcentral.com/er-pubs
Environmental Reviews
Draft
13
In terms of carbon dynamics at the landscape scale, land-use changes caused by conventional oil 285
production and oil sands operations, including seismic surveys, were found to contribute relatively small 286
portions (no more than 4%) of greenhouse gases to lifecycle emissions when measured in California and 287
Alberta (Yeh et al. 2010). However, these estimates assumed only aboveground biomass removal, with 288
no disturbance of soil carbon, as well as 100% vegetation recovery, which has typically not been 289
achieved. Although Kurz et al. (2013) stated that the current rates of disturbances and forest 290
management are overall sustainable with regard to biomass and total ecosystem carbon stocks, they 291
recognized that within regions of high industrial development in the boreal zone, the cumulative impact 292
of human and natural disturbances may turn these areas from carbon sinks to carbon sources. Further 293
research is needed to determine whether both conventional and modern LIS lines might contribute to 294
such a shift. 295
Changes in hydrology associated with seismic line construction in boreal peatlands may also lead 296
to drawdown of the water table, which may change vegetation composition and consequently carbon 297
dynamics. For example, water table drawdown can lead to increased coverage of shrubs (carbon sink), 298
but an even more substantial decrease in Sphagnum L. cover (carbon source) (Munir et al. 2014). Strack 299
et al. (2014) concluded that under very dry conditions in peatlands, greenhouse gas emissions will 300
remain high, whereas under very wet conditions (often observed on seismic lines, relative to sites 301
adjacent to the line), abundant graminoid cover may increase CO2 uptake, but may also create areas of 302
high CH4 flux, potentially leading to the site becoming a carbon source. Clearly the removal of vegetation 303
during the construction of linear disturbances and its effects on soil moisture and water table position, 304
as well as the shifts in vegetation composition that occur during site recovery, will have effects on 305
carbon dynamics, but these effects are not easily predictable. 306
Page 13 of 60
https://mc06.manuscriptcentral.com/er-pubs
Environmental Reviews
Draft
14
2.2. Edge influence: complex dynamic of environmental and plant interactions 307
The extent of the environmental changes discussed often goes beyond the edges of the seismic 308
lines (and other disturbances) and into the adjacent ecosystem, effectively magnifying the impacts over 309
an area much larger than the seismic line (Porensky and Young 2013). The spatial accumulation of all 310
edges determines the total impact of edges in fragmented landscapes (Ewers and Banks-Leite 2013). The 311
ubiquity of seismic lines makes them the main source of anthropogenic edges. Indeed, in boreal regions 312
in western Canada, seismic lines accounted for 80% of all edges from linear disturbances (Pattison et al. 313
2016). 314
Edge effects are often neglected when assessing the impact of linear disturbances, as the 315
primary focus remains on the conditions and habitat changes on the cleared terrain (i.e., the line itself). 316
However, the indirect effects of linear disturbance spreading into adjacent areas may include changes in 317
physical and chemical conditions, plant growth, and wildlife behaviour, as well as interactions among 318
these factors (CAPP 2004). Given their elongated shape, linear disturbances such as seismic lines create 319
more edge per unit area than non-linear disturbances such as cutblocks (CAPP 2004), though the 320
magnitude of edge influence along linear disturbances may be no greater than for other edge types. 321
Manifestation of edge influence in plant responses is complex and will differ among vegetation 322
types according to climatic conditions and limiting environmental factors. Increased growth rates of 323
trees growing at edges have been reported for seismic line edges (e.g., Revel et al. 1984; Bella 1986; 324
MacFarlane 2003), although these growth responses depended on stand type. For instance, MacFarlane 325
(2003) found that the initial growth increase along the seismic line edges was observed for deciduous, 326
but not coniferous trees, whereas Revel et al. (1984) found that the mean height of coniferous tree 327
species adjacent to seismic lines was greater than the mean height of trees in the undisturbed interior 328
forest. 329
Page 14 of 60
https://mc06.manuscriptcentral.com/er-pubs
Environmental Reviews
Draft
15
With an increase in tree growth along line edges, the competitive balance may be shifted, 330
potentially to the disadvantage of understory vegetation such as low shrubs, herbaceous plants, and 331
bryophytes (Gignac and Dale 2007; Dabros et al. 2017). Competitive balance could be further affected 332
by an increase in opportunistic, disturbance-tolerant, often-invasive species at and near the edges 333
(Honnay et al. 2002; Finnegan et al. 2018). The presence and spread of these species could be related to 334
various factors, such as human and machinery traffic during construction of the linear disturbance 335
(Meunier and Lavoie 2012), certain wildlife species, which preferentially use seismic lines (Latham et al. 336
2011a; Tigner et al. 2014), and early reclamation attempts using agronomic mixes not native to forests 337
(Revel et al. 1984; MacFarlane 2003). 338
Wind conditions also are affected at the disturbance edge, with wind intensity potentially 339
decreasing exponentially as one moves into the adjacent forest (Chen et al. 1995). This may contribute 340
to increased windthrow and tree mortality along edges (Williams-Linera 1990; Laurance et al. 1998; 341
Burton 2002; Dabros et al. 2017). Increased tree mortality and the presence of deadwood along line 342
edges may in turn affect the abundance of certain species of fungi, lichens, and mosses, which often 343
grow on deadwood (Dittrich et al. 2014). Meanwhile, the creation of microsites and microhabitats may 344
attract many arthropod species, as well as small mammals, birds, and wildlife in general (Harper et al. 345
2014), whose presence and interactions will affect vegetation abundance and growth, contributing to 346
different species composition along seismic lines edges. 347
2.3. Plant responses to altered environmental conditions 348
2.3.1 Vascular plants: boreal ecosystems 349
After natural disturbances such as fires, boreal and arctic ecosystems usually start regenerating 350
within the next growing season, progressing through different stages of succession towards the pre-351
disturbance state. Seismic lines, which have no natural analog, often do not follow such successional 352
Page 15 of 60
https://mc06.manuscriptcentral.com/er-pubs
Environmental Reviews
Draft
16
trajectory, remaining instead in early successional stages (van Rensen et al. 2015). This implies the 353
presence of key factors that hinder the recovery of seismic lines to a pre-disturbance state. 354
The progression of regenerative processes and succession on conventional seismic lines has 355
been examined and evaluated on a landscape scale by Lee and Boutin (2006). They reported that even 356
after 35 years, more than 60% of the seismic lines showed little or no recovery back to a forested state. 357
Likewise, Finnegan et al. (2018) found that in the lower and upper foothills and subalpine regions of 358
Alberta, for understory vegetation, disturbance-tolerant species were more abundant on seismic lines 359
and line edges in comparison to interior forest, even decades after the line construction, with the lines 360
appearing to remain indefinitely in an early successional state. 361
On a finer scale, MacFarlane (2003) found that in the central mixedwood sub-region of Alberta, 362
the composition of the vascular understory on conventional seismic lines and early versions of LIS lines 363
was still significantly different from that of the interior forests after up to 30 years. This indicates 364
arrested succession, where the system does not seem to progress to what it used to be before the 365
disturbance. MacFarlane (2003) attributed competition from invasive species as a major factor 366
influencing these results. 367
The competitive advantage of non-native and invasive vegetation is a likely factor hindering 368
growth and recovery of native tree species on seismic lines, even those that are already established. 369
Indeed, although Revel et al. (1984) reported the presence of native vegetation, including tree seedlings, 370
on seismic lines in northeastern Alberta, they also noted that the growth of these seedlings was much 371
slower on the lines than in the adjacent and interior forest, with invasive vegetation on lines being one 372
of the factors contributing to that slow growth. Aggressive and fast-growing invasive graminoids often 373
establish abundantly on seismic lines in boreal regions of Alberta, growing to around 1 m in height, 374
which can result in the shading and smothering of small conifer seedlings. These include bluejoint 375
reedgrass (Calamagrostis canadensis (Michaux) Palisot de Beauvois) and water sedge (Carex 376
Page 16 of 60
https://mc06.manuscriptcentral.com/er-pubs
Environmental Reviews
Draft
17
aquatilis Wahlenberg) under drier and wetter conditions, respectively (A. Dabros, personal observation, 377
2014-2017). Furthermore, wind speed in seismic line corridors was seven times stronger than in the 378
adjacent control forest, resulting in five times further experimental dispersal of the seeds of weedy 379
species on seismic lines than in the forest (S. Nielsen, personal communication 2017). 380
Habitat type also plays a major role in plant recolonization and subsequent persistence and 381
growth of different plant species on seismic lines. van Rensen et al. (2015) concluded that for seismic 382
lines in northeastern Alberta, terrain wetness and the presence of adjacent fen ecosites had the 383
strongest negative effect on regeneration patterns, with the lines found in the wettest sites failing to 384
recover even 50 years after initial disturbance. 385
The degree of plant recovery on seismic lines will also affect interactions with wildlife. For 386
example, Kansas et al. (2015) found that, in comparison to other ecosite types, poor recovery on LIS 387
lines in bogs and poor fens in northeastern Alberta provided less visual obstruction for wolves (Canis 388
lupus L.) travelling on seismic lines to hunt woodland caribou (Rangifer tarandus caribou (Gmelin). Thus, 389
to reduce the negative impact of seismic lines on wolf–caribou predation dynamics, Kansas et al. (2015) 390
have suggested that restoration efforts focus on seismic lines showing poor recovery, namely those in 391
bogs and poor fens (see also van Rensen et al. 2015), which are also habitats preferred by caribou 392
(Neufeld 2006; Latham et al. 2011a). More recently, Dickie et al. (2017) suggested that since most of the 393
movement efficiency afforded to wolves by seismic lines is mediated when vegetation height exceeds 394
0.5 m, active restoration could be focused in areas that have not met this height. 395
Wildlife using seismic lines as corridors for easier movement may also contribute to line 396
regeneration by acting as dispersal vector for seeds of both desirable and undesirable plants (Tigner et 397
al. 2014), changing the competitive dynamics of plant species. An additional factor associated with 398
slower growth of trees on seismic lines in comparison to adjacent interior forest may be increased 399
browse damage by ungulates and other herbivores (Revel et al. 1984). 400
Page 17 of 60
https://mc06.manuscriptcentral.com/er-pubs
Environmental Reviews
Draft
18
Growing substrate also plays a major role in plant recolonization and subsequent persistence 401
and growth of different plant species on seismic lines. For example, lodgepole pine (Pinus 402
contorta Douglas ex Loudon) regeneration was better on exposed mineral soil and under dry conditions, 403
whereas black spruce (Picea mariana (Miller) Britton, Sterns & Poggenburgh) and white spruce (Picea 404
glauca (Moench) Voss) were the dominant conifers that regenerated on moist to wet sites on 405
conventional seismic lines in the boreal forests of Alberta (Revel et al. 1984). Such ecological knowledge 406
is crucial for application of silvicultural methods in restoration. 407
Post-disturbance regeneration relies on various factors, including dispersal capacity, habitat 408
conditions, and biotic and abiotic interactions (Baker et al. 2013). The characteristics of seismic lines and 409
their impacts on environmental factors will, therefore, affect natural regeneration and successional 410
trajectories. These processes can be further altered by human intervention, either negatively (e.g., 411
through the reuse of the lines for all-terrain vehicles or snowmobiles) or positively (e.g., through 412
reclamation and restoration activities, such as silvicultural practices to improve conditions for plant 413
establishment, or direct seeding and planting, respectively). 414
2.3.2. Vascular plants: tundra 415
In contrast to the situation in boreal regions, where wetlands are less resilient than uplands, 416
wetland ecosystems in the Arctic are more likely to recover faster, or the magnitude of seismic damage 417
is less intense, relative to Arctic uplands (Hernandez 1973; Emers et al. 1995; Jorgenson et al. 2010). For 418
example, Hernandez (1973) observed that wetter habitats had more roots and rhizomes, which during 419
winter seismic operations effectively reduced the degree of surface disturbance. Overall, regardless of 420
habitat type (drier or wetter), the commonly reported patterns of recovery on seismic lines in the Arctic 421
have been characterized by i) significantly increased cover of graminoids, forbs, and deciduous shrubs; 422
and, ii) frequent decreases in evergreen shrubs and/or bryophytes, relative to their respective 423
undisturbed sites (e.g., Emers et al. 1995; Kemper and Macdonald 2009b; Jorgenson et al. 2010). 424
Page 18 of 60
https://mc06.manuscriptcentral.com/er-pubs
Environmental Reviews
Draft
19
Rapid recolonization of disturbed sites by aggressive rhizomatous graminoids, especially at sites 425
severely disturbed by compression or subsidence of seismic trails, could lead to significant changes in 426
species composition. Such changes may occur partially through competitive exclusion of more damage-427
susceptible vegetation types, such as shrubs or bryophytes (Emers et al. 1995, Jorgenson et al. 2010). 428
The flush of nutrients released through a sharp increase in decomposition immediately after 429
disturbance, resulting from increased heat transfer under wetter conditions (Chapin and Shaver 1981), 430
may further benefit opportunistic graminoids (Emers et al. 1995). In the drier upland tundra, some grass 431
species have been similarly successful in taking advantage of nutrient-enriched conditions and 432
establishing dominance over other non-grass species after seismic line disturbances (Bliss and Wein 433
1972; Hernandez 1973; Emers et al. 1995; Kemper and Macdonald 2009a). On the other hand, forb 434
species show an initial reduction in cover following seismic disturbance in arctic environments, but then 435
rebound through opportunistic ruderal responses, successfully recolonizing lines in the early years and 436
often creating higher cover than occurs at undisturbed reference sites, though sometimes not 437
permanently (Emers et al. 1995; Jorgenson et al. 2010). 438
Exposure of mineral soil through blading and scuffing techniques, often more pronounced on 439
mesic sites than in wetter habitats, also created conditions advantageous for colonization by grasses and 440
forbs, which have been shown to replace original pre-disturbance vegetation types on seismic lines 441
(Jorgenson et al. 2010). Furthermore, at the drier sites, which were originally dominated by graminoids 442
and which remained relatively dry after seismic disturbance, certain grass species became much denser 443
in comparison to undisturbed areas, remaining visible for many years after disturbance (Jorgenson et al. 444
2010). 445
The cover of deciduous shrubs, such as birch (Betula spp L.), willow (Salix spp. L) and alder 446
(Alnus spp. L), has also been observed to increase on seismic lines in the low-arctic coastal plains tundra 447
of Alaska and Northwest Territories (Jorgenson et al. 2010; Kemper and Macdonald 2009a). These 448
Page 19 of 60
https://mc06.manuscriptcentral.com/er-pubs
Environmental Reviews
Draft
20
changes remained even 20-30 years after disturbance (Kemper and Macdonald 2009a). Jorgenson et al. 449
(2010) attributed this increased cover to general adaptation to disturbance (e.g., river flooding and 450
grazing) among deciduous shrubs such as willows. Potentially warmer soils and higher decomposition 451
rates leading to increased nutrient concentrations on seismic lines (Emers et al. 1995) may also be 452
advantageous and play a role in successful recolonization and growth of deciduous shrubs. Interestingly, 453
most research, with the exception of Kemper and Macdonald (2009a), indicates that this advantage 454
seemed less likely to extend to evergreen shrubs studied across seismic disturbances in the arctic (Bliss 455
and Wein 1972; Hernandez 1973; Felix and Raynolds 1989; Emers et al. 1995; Jorgenson et al. 2010). 456
Decreased abundance of evergreen shrubs on seismic lines in arctic plant communities has been 457
attributed to their low photosynthetic capacity and higher (relative to deciduous shrubs) nutritional 458
storage in the aboveground parts of the plant, which are more directly damaged during seismic 459
operations (Starr et al. 2008; Jorgenson et al. 2010). Overall, deciduous species, which are often 460
broadleaf, have been reported to grow faster because of their usually higher specific leaf area (Antúnez 461
et al. 2001), which could also contribute to their competitive advantage in recolonization of seismic 462
lines. 463
2.3.3. Non-vascular plants and lichens: boreal and tundra ecosystems 464
In forested lands, the canopy openings generally found at disturbed sites and the higher levels 465
of solar radiation usually found there may not be optimal for many bryophyte species, which are often 466
better adapted to shaded, cool, and moist conditions (Marschall and Proctor 2004). Indeed, in boreal 467
forests, lower bryophyte cover was found on both conventional seismic lines (Revel et al. 1984) and LIS 468
lines (Dabros et al. 2017). Likewise, increased light levels were observed on the lines and line edges by 469
Dabros et al. (2017), which parallels the increased light levels found on linear disturbances by Pohlman 470
et al. (2007). In comparison to the adjacent boreal forest, lower bryophyte cover was also observed on 471
other types of linear disturbances (e.g., at the edges of power line clearings in the boreal forests of 472
Page 20 of 60
https://mc06.manuscriptcentral.com/er-pubs
Environmental Reviews
Draft
21
Norway; Eldegard et al. 2015). However, these general trends were not observed in wide and open 473
conventional seismic lines in the treed peatlands of northwestern Alberta (A. Dabros, unpublished data, 474
2017; Fig. 1b), where species of Sphagnum L., were highly abundant. Despite higher light levels, the 475
higher moisture conditions found on the lines appeared to be the driving factor for the presence of 476
Sphagnum, which is an indicator of wet conditions. 477
Slow recovery to pre-disturbance conditions have also been reported for bryophytes on seismic 478
lines in arctic ecosystems (Hernandez 1973; Kemper and Macdonald 2009a, 2009b; Jorgenson et al. 479
2010). Low growth rates (especially for common northern species of late successional feathermosses) 480
and the competitive disadvantage for nutrients and moisture of bryophytes (which lack a vascular 481
system and depend on external hydration) are some of the factors that may contribute to this slow 482
recovery (Jorgenson et al. 2010). Early successional moss species and crustose lichens were more likely 483
to successfully recolonize exposed mineral soil after seismic operations (Jorgenson et al. 2010), but 484
other lichen species recovered much more slowly, in both the short term (Hernandez 1973; Babb and 485
Bliss 1974; Kemper and Macdonald 2009b) and the long term (Kemper and Macdonald 2009a; Jorgenson 486
et al. 2010). 487
2.4. Behavioural and population effects on fauna 488
The effects of seismic lines on wildlife are complex and multifaceted, and will vary with line 489
characteristics, such as width, age, and level of recovery, and with the wildlife species involved 490
(Ashenhurst and Hannon 2008; Bayne et al. 2011; Tigner et al. 2014, 2015). The effects may be direct, 491
such as habitat degradation because of vegetation clearing, or avoidance of the line by certain species 492
because of decreased habitat quality and food resources in the vicinity (CAPP 2004; Wilson 2011); or 493
indirect, such as increased risk of predation through facilitation of predator movement (CAPP 2004; 494
Ashenhurst and Hannon 2008; Latham et al. 2011a). 495
Page 21 of 60
https://mc06.manuscriptcentral.com/er-pubs
Environmental Reviews
Draft
22
The impact of seismic lines on wildlife also may differ on a temporal scale: immediate (e.g., 496
destruction of rabbit burrows during construction and operation of the lines (Wilson 2011)); 497
intermittent (e.g., noise disturbance by all-terrain vehicle traffic after the line closure (Pigeon et al. 498
2016)), or prolonged (e.g., changes in dynamics of predation, or behavioural changes connected to 499
territory size and intra-species competition (Latham et al. 2011b; Bayne et al. 2011; Machtans 2006)). 500
The impact also differs spatially, with effects more apparent at a local scale and less clear at a regional 501
scale (Bayne et al. 2011). 502
With respect to bird species, their behavioural responses to seismic lines may range from a total 503
avoidance and exclusion of lines from their territories (Ortega and Capen 1999; Machtans 2006, 504
Ashenhurst and Hannon 2008), to actually selecting for more open conditions found on seismic lines, or 505
not responding to this disturbance at all (Bayne et al. 2011; Machtans 2006). These responses may 506
depend on the type of seismic line, i.e., birds may perceive older conventional lines differently from 507
newer LIS lines. For example, Ovenbirds (Seiurus aurocapilla L.) used conventional lines as territory 508
boundaries, but incorporated LIS lines into their territories (Bayne et al. 2005). This may be partially 509
explained by the greater width of the conventional lines, as well as their straight nature, relative to the 510
narrower, meandering LIS lines. However, as canopy closure increased and amount of bare ground 511
decreased over time, conventional seismic lines were more frequently included within Ovenbird 512
territories (Bayne et al. 2011). 513
The regional abundance and density of species can also modulate behavioural responses to 514
seismic lines. For example, in high-quality habitats with high densities of Ovenbirds, conventional 515
seismic lines delimited the location and size of their territories, regardless of the level of vegetation 516
recovery. However, in low-quality Ovenbird habitat, seismic lines had a limited effect on territorial 517
behaviour (Bayne et al. 2011). Other boreal bird species, including the American Robin (Turdus 518
migratorius L.), Yellow Warbler (Dendroica petechia L.), and Warbling Vireo (Vireo gilvus Vieillot), 519
Page 22 of 60
https://mc06.manuscriptcentral.com/er-pubs
Environmental Reviews
Draft
23
experienced small increases in abundance with increased density of linear features, but the models had 520
low predictive power (Bayne et al. 2011). 521
Assessment of habitat quality and resource availability for birds on and around seismic lines has 522
led indirectly to research on another important group of organisms, the invertebrates. Lankau et al. 523
(2013) found there was less leaf litter on seismic lines, and hence reduced abundance of arthropods. On 524
the other hand, Riva et al. (2018) found higher butterfly abundance and diversity on 9 m wide seismic 525
lines, but not on low impact 3 m wide lines, which again shows that the line type is an important factor 526
in predicting the behaviour of fauna. Other than these studies, there appears to be no direct studies on 527
the effects of seismic lines on invertebrates, even if they are the largest and most diverse group of 528
organisms in most ecosystems, and despite the crucial ecological functions they play, including 529
decomposition, nutrient release, and carbon cycling (SFMN 1999; Abele 2014). Research is, however, 530
currently underway in northeastern Alberta to assess the cumulative effects of seismic lines and other 531
disturbances on beetles (D. Langor et al., personal communication, 2017), and spiders (J. Pinzon, 532
personal communication, 2017). 533
Presumably, small species such as invertebrates may be less affected by seismic lines in 534
comparison to bigger species with considerably larger territories. For example, insects may shift their 535
territories into the interior forest, away from the lines, but for large mammals the fragmented habitat 536
may not be suitable enough and they may choose to enlarge their territory and include the lower quality 537
habitat found on seismic lines (Ashenhurst and Hannon 2008). This, however, may result in increased 538
energetic costs, as a result of having to traverse a larger area in search for resources. On the other hand, 539
as was discussed earlier, certain species, including birds (Bayne et al. 2011) and butterflies (Riva et al. 540
2018), may actually find that the early seral stages found on seismic lines are more suitable in terms of 541
their resource requirements. 542
Page 23 of 60
https://mc06.manuscriptcentral.com/er-pubs
Environmental Reviews
Draft
24
Wide conventional seismic lines running through a dense forest often facilitate the movement 543
of some larger mammals. For example, Tigner et al. (2014) found that in general, black bears (Ursus 544
americanus Pallas) used seismic lines that were wider than 2 m more than forest interiors (though Linke 545
et al. (2005) found that seismic line density did not explain landscape use by grizzly bears (Ursus arctos 546
L.)). In contrast, smaller mammals such as martens (Martes americana (Turton)), avoided lines that were 547
open and wider than 2 m (Tigner et al. 2015). 548
Wolves have also shown a strong preference for conventional seismic lines, especially during the 549
snow-free season (Latham et al. 2011a). Furthermore, Dickie (2015) found that conventional seismic 550
lines significantly increased wolves’ rate of travel, relative to both LIS lines and the interior forest. Dickie 551
et al. (2017) also found that wolves selected seismic lines with shorter vegetation and traveled faster on 552
those with shorter, sparser vegetation and increased vegetation variability. 553
Preferential use of seismic lines by predators, such as bears and wolves, may alter their ability to 554
locate and capture prey, including caribou and other ungulates. Whittington et al. (2011) and McKenzie 555
et al. (2012) found evidence for increased encounters between wolves and caribou on seismic lines, 556
whereas James and Stuart-Smith (2000) found evidence for increased risk of wolf predation on caribou 557
close to linear corridors. Furthermore, DeMars and Boutin (2017) found that seismic lines increase 558
wolves’ and black bears’ selection of peatlands, which negatively impacted survival of caribou neonate 559
calves, since peatlands are highly used by females during the calving season. 560
These observations of changes in predator movement and predation have important 561
implications for woodland caribou. Woodland caribou populations are known to be declining across 562
most of their ranges and are currently considered threatened. Linear features are acknowledged as a 563
key limiting factor for populations in western Canada (Serrouya et al. 2017; Environment Canada 2011; 564
Hervieux et al. 2013). On their own, seismic lines may not have a direct or pronounced impact on 565
woodland caribou. For example, Dyer et al. (2002) determined that although roads with moderate traffic 566
Page 24 of 60
https://mc06.manuscriptcentral.com/er-pubs
Environmental Reviews
Draft
25
inhibited caribou movement to a certain extent, especially in winter, seismic lines did not present any 567
barrier effects. However, in the context of predator–prey dynamics, linear disturbances such as seismic 568
lines facilitate the movement of wolves, potentially making it easier for them to reach and hunt down 569
their prey (Latham et al. 2011a; McKenzie et al. 2012; Dickie 2015; Dickie et al. 2017). 570
Predation by wolves has been considered one of the most significant forces driving caribou 571
decline (McLoughlin et al. 2003; Hervieux et al. 2013). Linear disturbances create a maze of early seral 572
habitats that attract the primary prey of wolf, especially moose (Alces alces L.) and deer (Cervidae 573
Goldfuss), thus buoying wolf populations in caribou habitat (Hebblewhite et al. 2007). Perhaps not 574
coincidentally, woodland caribou have been found to use areas close to linear disturbances less often 575
than expected, especially in the snow-free season, which is where and when most caribou deaths occur 576
(Dyer et al. 2002; Neufeld 2006). 577
Deliberate avoidance of seismic lines by caribou leads to functional loss of otherwise suitable 578
habitat for caribou (Latham et al. 2011a). Using resource selection models for wolves, Latham et al. 579
(2011a) found positive selection for linear features. Seismic lines have also contributed to a shift in 580
spatial separation between wolves and caribou as a result of increased industrial activity and 581
disturbance (James et al. 2004; Latham et al. 2011b). In addition, behavioural responses to human 582
activities on linear features were clearly reflected through increased physiological and nutritional stress 583
of caribou when there was increased presence of humans on primary roads, as indicated by Wasser et 584
al. (2011). As a result of this wide body of literature, seismic lines have been highlighted as a key factor 585
to tackle in woodland caribou population recovery (Environment Canada 2011; 2012). Through these 586
various examples of mammal responses to seismic lines, it is clear that although the characteristics and 587
behavioural responses of wildlife species will influence how they are affected by seismic lines, the 588
characteristics of the lines themselves will inevitably play a major role. 589
Page 25 of 60
https://mc06.manuscriptcentral.com/er-pubs
Environmental Reviews
Draft
26
2.5. Effects of post-development human use 590
A key issue often hampering vegetation recovery along conventional seismic lines is their 591
continued use after the exploration program as access routes for trapping, hunting, and other activities. 592
The lack of legal obligations regarding line reclamation has resulted in many seismic lines providing 593
access for all-terrain vehicles and snowmobiles, which can lead to increased hunting and poaching, 594
indirect disturbance (due to human presence, noise, light, and air pollution), and spread of undesirable 595
plant species. All of these factors can have significant adverse effects on soil and vegetation, resulting in 596
delays to regeneration (EMR 2006; van Rensen et al. 2015). 597
Even a single pass by an all-terrain vehicle can result in substantial damage under some 598
conditions, as Revel et al. (1984) found while studying regeneration along conventional seismic lines in 599
northeastern Alberta. They observed little conifer regeneration on lines where all-terrain vehicles had 600
been used, because of both water channelization and subsequent erosion, and increased soil 601
compaction. Similarly, van Rensen et al. 2015 noted that the greatest impact on vegetation recovery 602
along seismic lines occurred near human access routes, which further emphasizes the impact of off-603
highway vehicle use on vegetation recovery. However, Pigeon et al. (2016) found that off-highway 604
vehicle use was mainly associated with local topography and vegetation attributes of seismic lines that 605
facilitated ease of travel, while broad-scale landscape attributes associated with industrial use, 606
recreational access, or hunting activities did not explain levels of off-highway vehicles use. Clearly, off-607
highway vehicles have significant impacts on the recovery potential of seismic lines, particularly in the 608
boreal forest. Any attempts to facilitate vegetation recovery along these lines must take into 609
consideration human access and use of seismic lines. 610
3. Regulatory aspects and reclamation practices 611
Regulations represent a potentially influential tool in seismic line development and reclamation, 612
as their progressive evolution attests. Early regulations (i.e., circa 1940 and 1950) focused largely on 613
Page 26 of 60
https://mc06.manuscriptcentral.com/er-pubs
Environmental Reviews
Draft
27
tracking exploration locations with little regard for ecological impacts other than disposal of refuse (e.g., 614
Government of Alberta 1941). These regulations were eventually updated to foster more advanced 615
planning to tackle adverse ecological effects (e.g. Government of Alberta 1978; Government of Alberta 616
1990). Currently, regulations generally encourage—but do not require—LIS practices and the use of 617
advanced planning and surveying techniques (e.g., British Columbia Oil & Gas Commission 2016; 618
Government of Alberta 2006; Yukon Government 2006). Current regulations also encourage reuse of 619
existing lines for oil and gas exploration where natural vegetation regrowth is low (Alberta Environment 620
2006; British Columbia Oil & Gas Commission 2016; Government of Northwest Territories 2012; Yukon 621
Government 2006). 622
Most provinces and territories have adopted similar best management practices and encourage 623
the use of LIS techniques; however, seismic lines up to 5 m wide are still permitted in most jurisdictions, 624
with appropriate justification (Alberta Environment 2006; British Columbia Oil & Gas Commission 2016; 625
Government of Northwest Territories 2012; Yukon Government 2006). In addition, few of the 626
regulations explicitly require reclamation of seismic lines to a forested ecosystem. Those regulations 627
that do discuss reclamation often focus on clean-up of refuse, limiting motorized access, or on slumping 628
and erosion along the lines (e.g. Government of Northwest Territories 2012). Although some regulations 629
do call for revegetation, they do not specify that the revegetation consist of woody species. In addition, 630
regulations explicitly focus on implementation monitoring (i.e., how closely treatments have followed 631
the standards), with little emphasis on effectiveness monitoring (i.e., how successful treatments have 632
been in re-establishing ecosystem services) (Machmer and Steeger 2002). 633
Recognizing the substantial backlog of legacy seismic lines that have not recovered back to 634
forest, many provinces have introduced initiatives that focus on restoration, with Alberta and British 635
Columbia having made the largest advances on this front. British Columbia has developed a framework 636
for restoration and associated monitoring for seismic lines within woodland caribou habitat (Golder 637
Page 27 of 60
https://mc06.manuscriptcentral.com/er-pubs
Environmental Reviews
Draft
28
Associates 2015) and is also testing alternative restoration techniques, such as snow fences to reduce 638
predator movement. In Alberta, the Alberta Land-use Framework (Government of Alberta 2008, 2016a) 639
and the Biodiversity Management Framework have emphasized restoration, introducing the topics of 640
conservation and biodiversity offsets (Habib et al. 2013). Also, Alberta has recently issued a new 641
framework for the restoration of Legacy Seismic Lines (Government of Alberta 2017), and has 642
committed to an ambitious restoration program focused on restoring 6000 km of seismic lines within 5 643
years as part of the draft plan for the Little Smoky and A La Peche caribou ranges (Government of 644
Alberta 2016b). Although these initiatives have not yet been fully implemented, they show the possible 645
policy arena within which seismic line restoration efforts are being designed. 646
3.1. Current practices for restoration of seismic lines 647
To address the significant backlog of seismic lines with stagnant recovery, several oil and gas 648
companies and provincial authorities, especially in British Columbia and Alberta, are implementing 649
restoration practices and monitoring their effectiveness (Golder Associates 2012; Pyper et al. 2014). 650
Introduction of the woodland caribou recovery strategy (Environment Canada 2012), which emphasized 651
the importance of restoration, has further contributed to on-the-ground linear restoration programs. 652
While different approaches to restoration are not discussed in the peer-reviewed literature, in 653
practice, there are two dominant approaches to restoration of seismic lines in forested landscapes: 654
habitat restoration and functional restoration (Pyper et al. 2014). Habitat restoration has the primary 655
goal of promoting vegetation recovery along seismic lines by addressing site-specific limitations, such as 656
the site being too wet or too dry, having its soil compacted, or lacking microsites suitable for 657
establishment and growth of seedlings (Lee and Boutin 2006; Golder Associates 2012; van Rensen et al. 658
2015). Functional restoration has the primary goal of reducing movement of predators along seismic 659
lines (Keim et al. 2014; Pyper et al. 2014). The latter approach is based on the fact that predators often 660
Page 28 of 60
https://mc06.manuscriptcentral.com/er-pubs
Environmental Reviews
Draft
29
use seismic lines as travel corridors, which increases the frequency of encounters between predators 661
such as wolves and prey such as woodland caribou (e.g., Latham et al. 2011a). 662
Given their aim of creating travel barriers, functional restoration treatments are often quite 663
different from habitat restoration methods, although there is obvious overlap between the two. For 664
example, placement of large piles of wood at irregular intervals along lines may be designed to reduce 665
use of lines by predators, but may also reduce human travel (especially with off-highway vehicles), 666
which can also be a key factor limiting recovery (van Rensen et al. 2015). It should be noted, however, 667
that functional restoration approaches show limited ability to recover forested habitat on seismic lines, 668
and thus may only prove beneficial for specific species such as wolves and woodland caribou. In 669
contrast, habitat restoration approaches that strive to re-establish forest vegetation have much broader 670
implications and benefits for a diverse suite of forest species. 671
Habitat restoration and functional restoration are defined in the context of woodland caribou 672
conservation, which has been the primary motivation for restoration efforts in western Canada. There 673
are at least three reasons for this. First, woodland caribou is a flagship and umbrella species for the 674
boreal forest, occurring at low densities in large patches of old-growth coniferous forests and boreal 675
peatland complexes (Environment Canada 2012); therefore, interventions fostering the recovery of 676
caribou habitat should also benefit the ecosystem at large. Second, boreal woodland caribou is a 677
threatened species, and many populations in western Canada face extirpation (COSEWIC 2011); seismic 678
lines significantly reduce the amount of undisturbed critical habitat available to caribou and increase 679
caribou predation, so seismic line restoration may play a crucial role in tackling this situation. Third, 680
provisions in the Canadian Species at Risk Act could lead to temporary prohibition of industrial activities 681
in caribou ranges where there is a risk of imminent extirpation, which would have dire economic 682
consequences (Hebblewhite 2017). 683
Page 29 of 60
https://mc06.manuscriptcentral.com/er-pubs
Environmental Reviews
Draft
30
A range of approaches has been developed to achieve restoration of seismic lines (e.g., Golder 684
Associates 2012; Pyper et al. 2014). This suite of techniques represents the typical restoration toolbox 685
that is currently available (Table 1). Most restoration programs use a subset of these methods, based on 686
the specific ecological conditions at sites (Golder Associates 2012; Pyper et al. 2014). These practices 687
continue to evolve—quite rapidly in some cases—as companies and agencies experiment with ways to 688
achieve restoration goals with maximum efficiency and effectiveness. Robust, replicated scientific trials 689
of the various restoration techniques are needed to enable an evaluation of their effectiveness and to 690
improve management practices over time. 691
4. Challenges and opportunities 692
The preceding sections have reviewed the literature on the impacts of seismic lines and the 693
approaches currently being used to restore these features to a functioning ecosystem. In the following 694
section, we examine some of the challenges and opportunities present in the successful restoration of 695
seismic lines. A more thorough understanding of these challenges and opportunities may help to shape 696
future research aimed at developing new approaches to benefit on-the-ground programs for the 697
restoration of seismic lines. 698
4.1. Definition of successful restoration 699
Despite substantial work on, and interest in, the restoration of legacy seismic lines, successful 700
restoration may be difficult to define, especially because different species have different habitat 701
requirements. The exact definition and objectives of restoration depends on the ecosystem in which the 702
line is found, the species that restoration is intended to benefit, and the processes and ecosystem 703
services that are being restored. While the definition of what constitutes successful restoration needs to 704
be tailored to the specific situation, shortening recovery to pre-existing conditions appears to be a 705
shared requisite. 706
Page 30 of 60
https://mc06.manuscriptcentral.com/er-pubs
Environmental Reviews
Draft
31
Defining and achieving restoration goals will also play an important role in future regulations. 707
For example, there is currently some debate about whether restoration should achieve purely functional 708
objectives (such as reducing movement efficiency of wolves) or whether a more habitat-based approach 709
(with a dual focus on re-establishing vegetation and reducing movement efficiency of wolves) is required 710
to deem restoration in woodland caribou habitat successful (Pyper et al. 2014). Similarly, there is a need 711
to better understand whether sites that may be on a trajectory toward a restored forest should count as 712
restored, or whether equivalence to adjacent forests must be achieved before restoration can be 713
deemed successful (Ray 2014). While recent efforts, such as the new restoration framework of the 714
province of Alberta (Government of Alberta 2017), reduce ambiguity in the definition of success, more 715
work is needed to advance this discussion in other jurisdictions and within the scientific community. 716
Similarly, determining whether successful restoration for one species, such as woodland caribou, 717
provides wide-ranging benefits for additional species is also a key area requiring future research. 718
4.2. Monitoring 719
Monitoring ensures that restoration programs do not devolve into “faith-based restoration,” 720
whereby the project is implemented with hopes of a positive outcome once the first segment of a 721
hypothetical recovery trajectory has been achieved (Hilderbrand et al. 2005). Credible monitoring 722
provides data to quantitatively assess whether ecological objectives have been achieved and over what 723
timeframes. Monitoring should not only provide a means to certify the effectiveness of treatments 724
applied, but should also enable the early detection of problematic areas where additional corrective 725
measures may be needed. A credible, consistent approach to monitoring has been identified as one of 726
the most pressing needs in seismic line restoration (Golder Associates 2012; Pyper et al. 2014). 727
Consequently, significant progress has been made on this topic in Alberta with the development of a 728
Provincial Restoration and Establishment Framework (Government of Alberta 2017). 729
Page 31 of 60
https://mc06.manuscriptcentral.com/er-pubs
Environmental Reviews
Draft
32
When designing a monitoring program, some of the typical questions that need to be asked 730
include: i) What components of the restored system will be measured and over what spatial scale, and 731
what metrics and benchmarks will be used to measure these components? ii) How will the data be 732
stored, managed, modelled, evaluated and analyzed? iii) How will the findings of monitoring affect the 733
management of the restoration program? iv) Who will communicate the results and to what audiences? 734
And last but not least v) Who will cover the monitoring costs? (Hooper et al. 2015). 735
A potential problem with monitoring is the cost, which may consume considerable resources 736
that could otherwise be applied to restoration. The use of new technologies, such as photogrammetry 737
with unmanned aerial vehicles (UAVs, commonly known as drones), whereby a detailed 3D model of the 738
ground and vegetation is generated from overlapping digital photographs captured at low altitude (<100 739
m above ground level), could help reduce monitoring costs (Zahawi et al. 2015). A recent study 740
comparing a point intercept survey of vegetation height on seismic lines with estimates derived from 741
UAV photogrammetry concluded that the latter can effectively replace the former, drastically reducing 742
the amount of time and effort required to complete a survey (Chen et al. 2017). Also, wireless sensor 743
networks (Mainwaring et al. 2002) based on inexpensive hardware connected to the Internet of Things 744
enabling two-way communication with the network (Atzori et al. 2010), can complement and enhance 745
remote sensing data. This possibility is being explored by the Boreal Ecosystem Recovery & Assessment 746
project (www.bera-project.org), which is also developing protocols to estimate survival and 747
establishment indicators of restoration success on seismic lines. Taking advantage of these rapidly 748
evolving technologies to improve monitoring effectiveness and efficiency is clearly an opportunity for 749
the scientific community. 750
Current monitoring efforts that rely on site-specific criteria may demonstrate the value of 751
“proof-of-concept” restoration projects; however, as restoration efforts are scaled up, more efficient 752
and repeatable techniques will be required. Again, remote sensing monitoring tools (e.g., Frolking et al. 753
Page 32 of 60
https://mc06.manuscriptcentral.com/er-pubs
Environmental Reviews
Draft
33
2009; Wulder and Franklin 2012; Lawley et al. 2016) could improve the speed and efficiency of 754
measuring habitat responses over time following restoration, and align with the identified need to 755
measure habitat response at large scales, rather than limiting monitoring to site-specific measurements 756
(Ray 2014). In addition, these tools can help to analyze variability within individual programs and 757
between different programs, to better assess which sites are succeeding and which are failing, and to 758
identify possible mechanisms for these responses. 759
4.3. Research needs 760
Substantial research has been conducted on seismic lines over the past 30 years or more, but 761
several significant knowledge gaps remain to be investigated. Firstly, more research into the landscape-762
level implications of LIS development is needed. Advances in LIS technology have significantly reduced 763
the footprint of individual seismic lines in boreal and tundra landscapes (e.g., Schneider et al. 2003), but 764
the relative number and density of seismic lines have increased dramatically (Latham and Boutin 2015). 765
For example, in some areas of Alberta’s oil sands deposits, seismic line grids with 45 × 45 m spacing are 766
common. As Kansas et al. (2015) noted, while there is an inherent assumption that LIS lines will recover 767
naturally because of lower disturbance and narrow width, the evidence to date is not clear. Thus, 768
research is still required to better understand the responses of understory vegetation to LIS programs, 769
the landscape implications of dense seismic line spacing, and to identify stand types that may be more 770
amenable to LIS development on the landscape. 771
Second, edge effects caused by seismic lines continue to be an area in need of research. For 772
example, research on the edge effects of seismic lines in different ecosystems, especially lowlands is 773
currently being initiated at a small scale for individual peatlands (Dabros unpublished data) and needs 774
further attention. Understanding the magnitude and extent of edge effects on different organisms and 775
processes, with consideration of different spatial scales (from site to landscape), would more accurately 776
reveal the actual level of disturbance that seismic lines cause for a range of species. In regions of dense 777
Page 33 of 60
https://mc06.manuscriptcentral.com/er-pubs
Environmental Reviews
Draft
34
3D seismic development, the footprint of disturbances may be much greater once edge effects are taken 778
into consideration (Dabros et al. 2017). Furthermore, on a temporal scale, short- and long-term effects 779
of cumulative disturbances across the landscape must be considered to assess the changes in edge 780
effect magnitude over time. 781
A third research need is to develop a better understanding of seismic line impacts on less 782
charismatic species. The effects of seismic lines on vegetation and charismatic wildlife has received 783
considerable attention in scientific and policy literature, but the effects of seismic lines on the most 784
diverse and abundant groups of living organisms, namely invertebrates, constitutes a significant 785
knowledge gap for which research is only now being initiated. These future studies should strive to 786
document and understand how individual responses at the site level translate into population and 787
ecosystem effects at the landscape level, as opposed to simply documenting patterns of fragmentation. 788
Fourth, prescribed burning, natural wildfire, and targeted forest harvesting are increasing in 789
their relevance to discussions about restoration of seismic lines. Seismic lines have no natural analog, 790
therefore the used of natural disturbance emulation may be more challenging than e.g., in forestry 791
practices. Nonetheless, practitioners and researchers have recently been advocating for more use of 792
fire, and even harvesting, in restoration programs. Specific to the use of fire as a restoration tool, 793
burning areas affected by dense seismic line development may reset the ecosystem to early successional 794
stages, thus effectively ‘erasing’ seismic lines. The effectiveness of fire as a restoration technique is 795
currently being evaluated through several research projects led by ecologists at the Canadian Forest 796
Service (within Natural Resources Canada) and the University of Alberta. Given how ubiquitous seismic 797
lines are in some parts of the boreal, the logistical and financial constraints, as well as the risk of fire 798
escape and human endangerment, should also be considered when evaluating this practice. Forest 799
harvesting, some have advocated, could also serve as a restoration tool by serving as a natural 800
disturbance analogue. Placement of such harvesting and prescribed burning events would need to 801
Page 34 of 60
https://mc06.manuscriptcentral.com/er-pubs
Environmental Reviews
Draft
35
consider the needs of species at a landscape scale, and the implications of a return to earlier 802
successional stages. This point of discussion is particularly relevant for woodland caribou ranges where 803
fragmentation and early successional habitats (Hebblewhite et al. 2007) are a key driver of population 804
decline (Environment Canada 2012). 805
Fifth, with respect to evaluating restoration success, one of the key limitations of current 806
monitoring programs is that most measurements are conducted at the site scale, with few 807
considerations for how habitat recovery may be measured at larger scales. While site-level monitoring 808
may be used to assess effectiveness of the restoration approach, remote sensing and spatial modelling 809
may be used to evaluate the broader landscape picture. Another obstacle is a lack of consistency in 810
monitoring efforts between programs (Golder Associates 2012; Pyper et al. 2014); in some cases, 811
monitoring goals are not clearly defined, or they lack a connection to larger goals for restoration of 812
woodland caribou (Pyper et al. 2014). These issues represent key obstacles to be overcome as programs 813
continue to evolve in support of efficiently monitoring habitat recovery. Developing monitoring 814
approaches that are applicable at multiple scales, and that enable learning based on past experiences, 815
represents a critical need in the field of seismic line restoration. 816
Finally, projecting future recovery probability based on current ecological conditions is also a 817
key area in need of research. For example, discussions have occurred about developing recovery 818
trajectories to help inform the possible paths that a recovering site may follow (Golder Associates 2015; 819
Ray 2014). In many ways, these recovery trajectories could emulate the growth-and-yield curves that 820
have been used by the forestry industry for many years to model and predict forest stand growth and 821
productivity over time (Davis et al. 2001). Ray (2014) also noted that “free-to-grow” metrics could be 822
used to help measure current recovery along seismic lines and as a predictive measure for future 823
outcomes of restoration efforts, especially at the sites where site recovery seems more probable, either 824
due to direct and deliberate actions such as tree planting, or where natural regeneration seems more 825
Page 35 of 60
https://mc06.manuscriptcentral.com/er-pubs
Environmental Reviews
Draft
36
probable. Free-to-grow metrics are regularly used in the forestry industry as short-term indicators that a 826
forest stand has reached sufficient height and vigour to be considered on a probable trajectory to a 827
mature forest. Although some limitations have been noted with respect to how accurately free-to-grow 828
systems represent growth of the target species (Lieffers et al. 2007), they remain an important tool that 829
could help in providing shorter-term indicators of the trajectory that a restored habitat may be on. 830
Development of such successional trajectories, or predictive models based on approaches like those of 831
free-to-grow metrics, could significantly benefit restoration programs. Such models should also take into 832
account how regeneration suitability may decline or improve for certain tree species as a result of 833
climate change (Erickson et al. 2015). 834
5. Conclusion 835
Seismic lines are the most pervasive linear disturbances in oil and gas rich areas in the boreal 836
and arctic regions of North America. This review has highlighted that by changing abiotic factors, these 837
ubiquitous linear features can lead to changes in ecosystem structure and function, affecting both plants 838
and fauna. At the landscape scale, the cumulative effects of seismic lines and other linear disturbances 839
also contribute heavily to landscape fragmentation. This fragmentation, paired with projected global 840
climatic changes for arctic and boreal regions, may eventually lead to imbalances of the ecosystem, 841
affecting its health and resilience. 842
To mediate these impacts, best practices have been adopted for seismic exploration in many 843
jurisdictions (AECOM 2009). In comparison to conventional seismic lines, the literature suggests that for 844
some species, narrower LIS lines do indeed have lower ecological effects at the site level (e.g., Bayne et 845
al. 2005; Tigner et al. 2015). However, considering the high density of LIS lines, and likely existence of 846
edge effects (Dabros et al. 2017), the actual environmental impact of these lines may be 847
underestimated. 848
Page 36 of 60
https://mc06.manuscriptcentral.com/er-pubs
Environmental Reviews
Draft
37
Given the amount of conventional seismic lines within boreal and arctic landscapes, large 849
restoration programs will be required to facilitate recovery of communities back to a natural pre-850
disturbance state (Finnegan et al 2018). This is particularly the case for sites that are either very wet, or 851
very dry (van Rensen et al. 2015). However, seismic lines represent site conditions that provide 852
additional challenges to restoration efforts, such as high shading, cold soils, high water tables, or in 853
some cases compacted soils. To be successful, restoration treatments must therefore clearly document 854
site limiting factors and address these factors through creation of microsites, facilitation of natural 855
regeneration, mechanical site preparation, and/or tree planting. 856
The costs, labour and logistical constrains necessary for restoration of all currently present 857
seismic lines may be a daunting and unrealistic undertaking. Given the scale of this challenge, 858
prioritization of seismic restoration efforts will be inevitable (van Rensen et al. 2015). As such, priority 859
must be established as to which areas need to be restored first, based on their ecological value in terms 860
of supporting biodiversity and/or vulnerable species, and provision of economic and ecosystem services. 861
One possibility could be to use of active restoration within woodland caribou ranges, and outside them, 862
use approaches to ‘erase’ seismic lines through forest harvesting or prescribed burning, which may 863
provide a more efficient means of achieving restoration objectives. 864
Preventative measures should also be taken to minimize future disturbances through integrated 865
land management and mitigation practices, which may reduce the overall footprint of cumulative 866
disturbances, including linear disturbances such as seismic lines. To facilitate more rapid recovery of LIS 867
lines, approaches should be tested which better create the necessary microsite conditions upon which 868
natural recovery may occur rapidly following the initial disturbance. 869
Page 37 of 60
https://mc06.manuscriptcentral.com/er-pubs
Environmental Reviews
Draft
38
Acknowledgements 870
The authors thank Dr. Erin Bayne, Dr. Scott Nielsen, and two anonymous reviewers for providing a 871
constructive review and thoughtful comments on this manuscript, Brenda Laishley and Marta Dabros for 872
thorough editorial work, and Sebastien Rodrigue for help with listing references and other formatting 873
issues. The authors also appreciate general support from the following management staff members at 874
Northern Forestry Centre (Canadian Forest Service): David Langor, Renée Lapointe, and Michael Norton. 875
This research was funded by NRCan project PERD 1C03.15. 876
877
References 878
Abele, S.E., Macdonald, S.E., and Spence, J.R. 2014. Cover type, environmental characteristics, and 879
conservation of terrestrial gastropod diversity in boreal mixedwood forests. Can. J. For. Res. 880
44(1):36-44. doi.org/10.1139/cjfr-2013-0210 881
AECOM. 2009. Considerations in developing oil and gas industry best practices in the north. Government 882
of Canada, Environmental Studies Research Fund, Whitehorse, Y.T. 883
Alberta Biodiversity Monitoring Institute (ABMI). 2016. Prioritizing zones for caribou habitat restoration 884
in the Canada’s Oil Sands Innovation Alliance (COSIA) area. Prepared for Canada’s Oil Sands 885
Innovation Alliance. Alberta Biodiversity Monitoring Institute, Edmonton, Alta. Available from 886
http://www.cosia.ca/uploads/documents/id27/COSIA_Prioritizing%20Zones_for_Restoring_Cari887
bou_Habitat.pdf [accessed 30 October 2017]. 888
Alberta Environment. 2006. “Policy and Procedures Document for Submitting the Geophysical Field 889
Report Form.” Edmonton, AB: Alberta Environment, Government of Alberta. 890
http://esrd.alberta.ca/forms-maps-services/forms/lands-forms/guides-forms-891
completion/documents/PolicyAndProceduresDocument-892
ForSubmittingTheGeophysicalFieldReportForm-Oct2006.pdf. 893
Page 38 of 60
https://mc06.manuscriptcentral.com/er-pubs
Environmental Reviews
Draft
39
Antúnez, I., Retamosa, E.C., and Villar, R. 2001. Relative growth rate in phylogenetically related 894
deciduous and evergreen woody species. Oecologia, 128(2):172–180. 895
doi:10.1007/s004420100645. 896
Arnup, R. 2000. Minimizing soil disturbance in forestry operations: a practical field guide for resource 897
managers and equipment operators in northeastern Ontario. The Lake Abitibi Model Forest, 898
Cochrane, Ont. 899
Ashenhurst, A.R., and Hannon, S.J. 2008. Effects of seismic lines on the abundance of breeding birds in 900
the Kendall Island Bird Sanctuary, Northwest Territories, Canada. Arctic, 61(2):190–198. 901
doi.org/10.7939/R36M3362Z 902
Atzori, L., Iera, A., and Morabito, G. 2010. The internet of things: a survey. Comput. Netw. 54(15):2787–903
2805. 904
Babb, T.A., and Bliss, L.C. 1974. Effects of physical disturbance on arctic vegetation in the Queen 905
Elizabeth Islands. J. Appl. Ecol. 11:549–562. doi.org/10.2307/2402208. 906
Baker, S.C., Spies, T.A., Wardlaw, T.J., Balmer, J., Franklin, J.F., and Jordan, G.J. 2013. The harvested side 907
of edges: effect of retained forests on the re-establishment of biodiversity in adjacent harvested 908
areas. For. Ecol. Manage. 302:107–121. 909
Bayne, E.M., Boutin, S., Tracz, B., and Charest, K. 2005. Functional and numerical responses of ovenbirds 910
(Seiurus aurocapilla) to changing seismic exploration practices in Alberta’s boreal forest. 911
Ecoscience, 12:216–222. 912
Bayne, E.M., Lankau, H., and Tigner, J. 2011. Ecologically-based criteria to assess the impact and 913
recovery of seismic lines: the importance of width, regeneration, and seismic density. University 914
of Alberta, Edmonton, Alta. Rep. No. 192. 915
Bella, I.E. 1986. Tree growth response along seismic lines in Alberta. For. Chron. 62(1):29–34. 916
Page 39 of 60
https://mc06.manuscriptcentral.com/er-pubs
Environmental Reviews
Draft
40
Bjorkman, A.D., Elmendorf, S.C., Beamish, A.L., Vellend, M., and Henry, G.H. 2015. Contrasting effects of 917
warming and increased snowfall on Arctic tundra plant phenology over the past two 918
decades. Glob. Change Biol. 21(12):4651–4661. 919
Bliss, L.C., and Wein, R.W. 1972. Plant community responses to disturbances in the western Canadian 920
Arctic. Can. J. Bot. 50(5):1097–1109. 921
Braverman, M., and Quinton, W.L. 2016. Hydrological impacts of seismic lines in the wetland-dominated 922
zone of thawing, discontinuous permafrost, Northwest Territories, Canada. Hydrol. Process. 923
30(15):2617–2627. 924
British Columbia Oil & Gas Commission. 2016. “Geophysical Exploration Application Manual (Version 925
1.19).” http://www.bcogc.ca/node/5821/download. 926
Burton, P.J. 2002. Effects of clearcut edges on trees in the sub-boreal spruce zone of Northwest-Central 927
British Columbia. Silva Fenn. 36(1):329–352. 928
Canadian Association of Petroleum Producers (CAPP). 2004. Guide: evolving approaches to minimize the 929
footprint of the Canadian oil and natural gas industry. CAPP, Calgary, Alta. 930
Canadian Association of Petroleum Producers (CAPP). 2017. Crude oil forecast, markets and 931
transportation. CAPP, Ottawa, Ont. 932
Chapin, F.S., III, and Shaver, G.R. 1981. Changes in soil properties and vegetation following disturbance 933
of Alaskan arctic tundra. J. Appl. Ecol. 18(2):605–617. Available from 934
http://www.jstor.org/stable/2402420 [accessed 23 August 2017]. 935
Chen, J., Franklin, J.F., and Spies, T.A. 1995. Growing-season microclimatic gradients from clearcut edges 936
into old-growth Douglas-fir forests. Ecol. Appl. 5(1):74–86. 937
Chen, S., McDermid, G.J., Castilla, G. and Linke, J. 2017. Measuring Vegetation Height in Linear 938
Disturbances in the Boreal Forest with UAV Photogrammetry. Remote Sensing, 9(12):1257. 939
Page 40 of 60
https://mc06.manuscriptcentral.com/er-pubs
Environmental Reviews
Draft
41
Christensen, T.R., Johansson, T., Åkerman, H.J., Mastepanov, M., Malmer, N., Friborg, T., Crill, P., and 940
Svensson, B.H. 2004. Thawing sub-arctic permafrost: effects on vegetation and methane 941
emissions. Geophys. Res. Lett. 31(4):L04501. doi:10.1029/2003GL018680. 942
Committee on the Status of Endangered Wildlife in Canada (COSEWIC). 2011. Designatable units for 943
caribou (Rangifer tarandus) in Canada. COSEWIC, Ottawa, Ont. 944
Dabros, A. 2008. Effects of simulated climate change on post-disturbance Populus tremuloides—Picea 945
mariana ecosystems in northwestern Quebec. Ph.D. thesis, Department of Natural Resource 946
Science, McGill University, Montreal, Que. 947
Dabros, A., Hammond, H.E.J., Pinzon J., Pinno B., and Langor D. 2017. Edge influence of low-impact 948
seismic lines for oil exploration on upland forest vegetation in northern Alberta (Canada). For. 949
Ecol. Manage. 400:278–288. doi: 10.1016/j.foreco.2017.06.030. 950
Davis, L.S., Johnson, K.N., Bettinger, P., and Howard, T.E. 2001. Forest management: to sustain 951
ecological, economic, and social values. 4th ed. McGraw-Hill Book Company, New York, N.Y. 952
DeMars, C.A., and Boutin, S. 2017. Nowhere to hide: Effects of linear features on predator–prey 953
dynamics in a large mammal system. J. Anim. Ecol. (in print, doi 10.1111/1365-2656.12760). 954
Dickie, M. 2015. The use of anthropogenic linear features by wolves in northeastern Alberta. M.Sc. 955
thesis, Department of Biological Sciences, University of Alberta, Edmonton, Alta. 956
Dickie, M., Serrouya. R., DeMars, C., Cranston, J., and Boutin, S. 2017. Evaluating functional recovery of 957
habitat for threatened woodland caribou. Ecosphere 8(9):e01936. 10.1002/ecs2.1936 958
Dittrich, S., Jacob, M., Bade, C., Leuschner, C., and Hauck, M. 2014. The significance of deadwood for 959
total bryophyte, lichen, and vascular plant diversity in an old-growth spruce forest. Plant Ecol. 960
215(10):1123–1137. 961
Page 41 of 60
https://mc06.manuscriptcentral.com/er-pubs
Environmental Reviews
Draft
42
Dorrepaal, E., Toet, S., van Logtestijn, R.S., Swart, E., van de Weg, M.J., Callaghan, T.V., and Aerts, R. 962
2009. Carbon respiration from subsurface peat accelerated by climate warming in the 963
subarctic. Nature, 460(7255):616. 964
Dunnigan, R.M. 1988. Compensation for timber damage on Alberta crown lands. Alberta Forest Service, 965
Timber Management Branch, Edmonton, Alta. 966
Dyer, S.J., O'Neill, J.P., Wasel, S.M., and Boutin, S. 2001. Avoidance of industrial development by 967
woodland caribou. J. Wildl. Manage. 65:531–542. doi: 10.2307/3803106. 968
Dyer, S.J., O'Neill, J.P., Wasel, S.M., and Boutin, S. 2002. Quantifying barrier effects of roads and seismic 969
lines on movements of female woodland caribou in northeastern Alberta. Can. J. 970
Zool. 80(5):839–845. 971
Eldegard, K., Totland, Ø., and Moe, S.R. 2015. Edge effects on plant communities along power line 972
clearings. J. Appl. Ecol. 52(4):871–880. 973
Emers, M., Jorgenson, J.C., and Raynolds, M.K. 1995. Response of arctic tundra plant communities to 974
winter vehicle disturbance. Can. J. Bot. 73(6):905–917. 975
Energy, Mines and Resources (EMR). 2006. Best management practices – oil and gas; seismic 976
exploration. Yukon Government, Energy Mines and Resources, Oil and Gas Management Branch, 977
Whitehorse, Y.T. 978
Environment Canada. 2011. Scientific assessment to support the identification of critical habitat for 979
woodland caribou (Rangifer tarandus caribou), boreal population, in Canada: 2011 update. 980
Environment Canada, Ottawa, Ont. 981
Environment Canada. 2012. Recovery strategy for the woodland caribou (Rangifer tarandus caribou), 982
boreal population, in Canada. Species at Risk Act Recovery Strategy Ser. Environment Canada, 983
Ottawa, Ont. 984
Page 42 of 60
https://mc06.manuscriptcentral.com/er-pubs
Environmental Reviews
Draft
43
Erickson, A., Nitschke, C., Coops, N., Cumming, S. and Stenhouse, G. 2015. Past-century decline in forest 985
regeneration potential across a latitudinal and elevational gradient in Canada. Ecol. Modelling 986
313:94–102. 987
Ewers, R.M., and Banks-Leite, C. 2013. Fragmentation impairs the microclimate buffering effect of 988
tropical forests PLOS 8(3): e58093 doi.org/10.1371/journal.pone.0058093 989
Felix, N.A., and Raynolds, M.K. 1989. The effects of winter seismic trails on tundra vegetation in 990
northeastern Alaska, U.S.A. Arctic Alp. Res. 21:188–202. 991
Finnegan, L., MacNearney, D., and Pigeon, K.E. 2018. Divergent patterns of understory forage growth 992
after seismic line exploration: Implications for caribou habitat restoration. For. Ecol. Manage. 993
409:634–652. 994
Forbes, B.C., and Jefferies, R.L. 1999. Revegetation of disturbed arctic sites: constraints and 995
applications. Biol. Conserv. 88(1):15–24. 996
Forbes, B.C., Ebersole, J.J., and Strandberg, B. 2001. Anthropogenic disturbance and patch dynamics in 997
circumpolar arctic ecosystems. Conserv. Biol. 15(4):954–969. 998
Frolking, S., Palace, M.W., Clark, D.B., Chambers, J.Q., Shugart, H.H., and Hurtt, G.C. 2009. Forest 999
disturbance and recovery: A general review in the context of spaceborne remote sensing of 1000
impacts on aboveground biomass and canopy structure. Journal of Geophysical Research: 1001
Biogeosciences 114(G2). 1002
Gignac, L.D., and Dale, M.R. 2007. Effects of size, shape, and edge on vegetation in remnants of the 1003
upland boreal mixed-wood forest in agro-environments of Alberta, Canada. Botany 85(3):273–1004
284. 1005
Golder Associates. 2012. Boreal caribou habitat restoration. Submitted to B.C. Ministry of Forests, Lands, 1006
and Natural Resource Operations. Golder Associates, Calgary, Alta. Rep. No. 12-1372-0012. 1007
Page 43 of 60
https://mc06.manuscriptcentral.com/er-pubs
Environmental Reviews
Draft
44
Golder Associates. 2015. Boreal caribou habitat restoration monitoring framework. Prepared for B.C. Oil 1008
and Gas Research and Innovation Fund. Golder Associates, Victoria, B.C. 1009
Government of Alberta. 1941. AR727-41: Regulations Governing Geophysical and Geological Exploration. 1010
Edmonton, AB: Alberta Gazette June 1941, Legislative Assembly Alberta. 1011
http://www.ourfutureourpast.ca/law/page.aspx?id=3059977. 1012
Government of Alberta. 1978. AR 423/78: Exploration Regulation. Edmonton, AB: Alberta Gazette Vol. 1013
74, No. 23. http://www.ourfutureourpast.ca/law/page.aspx?id=3188673. 1014
Government of Alberta. 1990. AR 32/90: Exploration Regulation. Edmonton, AB: Alberta Gazette Feb. 1015
1990. http://www.ourfutureourpast.ca/law/page.aspx?id=3201586. 1016
Government of Alberta. 2006. Alta Reg 284/2006: exploration regulation. Legislative Assembly of 1017
Alberta, Edmonton, Alta. Available from http://canlii.ca/t/82lg [accessed 11 August 2017]. 1018
Government of Alberta. 2008. Alberta land-use framework. Government of Alberta, Edmonton, Alta. 1019
Publ. No. I/3. 1020
Government of Alberta. 2016a. Land-use framework regional plans progress report: a review of our 1021
progress in 2014. Government of Alberta, Edmonton, Alta. 1022
Government of Alberta. 2016b. Draft Little Smoky and A La Peche range plan. Government of Alberta, 1023
Edmonton, Alta. 1024
Government of Alberta. 2017. Provincial Restoration and Establishment Framework for Legacy Seismic 1025
Lines in Alberta. Alberta Environment and Parks, Land and Environment Planning Branch. 1026
Government of Alberta, Edmonton, Alta. 1027
Government of the Northwest Territories (GNWT). 2012. Northwest Territories seismic operations. 1028
Northern land use guidelines. Vol. 09a. Available from 1029
Page 44 of 60
https://mc06.manuscriptcentral.com/er-pubs
Environmental Reviews
Draft
45
http://www.assembly.gov.nt.ca/sites/default/files/12-06-13td37-173.pdf [accessed 30 October 1030
2017]. 1031
Guan, X.J., Westbrook, C.J., and Spence, C. 2010. Shallow soil moisture–ground thaw interactions and 1032
controls–Part 1: Spatiotemporal patterns and correlations over a subarctic landscape. Hydrol. 1033
Earth Syst. Sci. 14(7):1375–1386. 1034
Haag, R.W., and Bliss, L.C. 1974. Energy budget changes following surface disturbance to upland 1035
tundra. J. Appl. Ecol. 11(1):355–374. 1036
Habib, T.J., Farr, D.R., Schneider, R.R., and Boutin, S. 2013. Economic and ecological outcomes of flexible 1037
biodiversity offset systems. Conserv. Biol. 27:1313–1323. 1038
Harper, K.A., Drapeau, P., Lesieur, D., and Bergeron, Y. 2014. Forest structure and composition at fire 1039
edges of different ages: evidence of persistent structural features on the landscape. For. Ecol. 1040
Manage. 314:131–140. 1041
Hebblewhite, M. 2017. Billion dollar boreal woodland caribou and the biodiversity impacts of the global 1042
oil and gas industry. Biol. Conserv. 206:102–111. 1043
Hebblewhite, M., Whittington, J., Bradley, M., Skinner, G., Dibb, A., and White, C.A. 2007. Conditions for 1044
caribou persistence in the wolf-elk-caribou systems of the Canadian Rockies. Rangifer, 27(4):79–1045
91. 1046
Hernandez, H. 1973. Natural plant recolonization of surficial disturbances, Tuktoyaktuk Peninsula region, 1047
Northwest Territories. Can. J. Bot. 51(11):2177–2196. 1048
Hervieux, D., Hebblewhite, M., DeCesare, N.J., Russell, M., Smith, K., Robertson, S., and Boutin, S. 2013. 1049
Widespread declines in woodland caribou (Rangifer tarandus caribou) continue in Alberta. Can. 1050
J. Zool. 91(12): 872–882. 1051
Page 45 of 60
https://mc06.manuscriptcentral.com/er-pubs
Environmental Reviews
Draft
46
Hilderbrand, R.H., Watts, A.C., and Randle, A.M. 2005. The myths of restoration ecology. Ecol. Soc. 1052
10(1):19. Available from http://www.ecologyandsociety.org/vol10/iss1/art19/ [accessed 23 1053
August 2017]. 1054
Hooper, M.J., Glomb, S.J., Harper, D.D., Hoelzle, T.B., McIntosh, L.M. and Mulligan, D.R. 2015. 1055
Integrated risk and recovery monitoring of ecosystem restorations on contaminated sites. 1056
Integr. Environ. Assess. Manage. 12(2):284–295. 1057
Honnay, O., Verheyen, K., and Hermy, M. 2002. Permeability of ancient forest edges for weedy plant 1058
species invasion. For. Ecol. Manage. 161(1):109–122. 1059
International Energy Agency (IEA). 2016. Energy policies of IEA countries: Canada 2015 review. Available 1060
from 1061
https://www.iea.org/publications/freepublications/publication/EnergyPoliciesofIEACountriesCa1062
nada2015Review.pdf [accessed 27 October 2017]. 1063
Intergovernmental Panel on Climate Change (IPCC). 2014. Climate Change 2014: Synthesis Report. 1064
Contribution of Working Groups I, II and III to the Fifth Assessment Report of the 1065
Intergovernmental Panel on Climate Change [Core Writing Team, R.K. Pachauri and L.A. Meyer 1066
(eds.)]. IPCC, Geneva, Switzerland, 151 pp. 1067
James, A.R., and Stuart-Smith, A.K. 2000. Distribution of caribou and wolves in relation to linear 1068
corridors. J. Wildl. Manage. 64(1): 154–159. 1069
James, A.R., Boutin, S., Hebert, D.M., and Rippin, A.B. 2004. Spatial separation of caribou from moose 1070
and its relation to predation by wolves. J. Wildl. Manage. 68(4):799–809. 1071
Jorgenson, J.C., Hoef, J.M.V., and Jorgenson, M.T. 2010. Long-term recovery patterns of arctic tundra 1072
after winter seismic exploration. Ecol. Appl. 20(1):205–221. 1073
Page 46 of 60
https://mc06.manuscriptcentral.com/er-pubs
Environmental Reviews
Draft
47
Kansas, J.L., Charlebois, M.L., and Skatter, H.G. 2015. Vegetation recovery on low impact seismic lines in 1074
Alberta’s oil sands and visual obstruction of wolves (Canis lupus) and woodland caribou 1075
(Rangifer tarandus caribou). Can. Wildl. Biol. Manage. 4(2):137–149. 1076
Kearns, N.B., Jean, M., Tissier, E.J., and Johnstone, J.F. 2015. Recovery of tundra vegetation three 1077
decades after hydrocarbon drilling with and without seeding of non-native grasses. Arctic, 1078
68(1):16–31. 1079
Kemper, J.T., and Macdonald, S.E. 2009a. Directional change in upland tundra plant communities 20-30 1080
years after seismic exploration in the Canadian low-arctic. J. Veg. Sci. 20(3):557–567. 1081
Kemper, J.T., and Macdonald, S.E. 2009b. Effects of contemporary winter seismic exploration on low 1082
Arctic plant communities and permafrost. Arctic Antarct. Alp. Res. 41(2):228–237. 1083
Kevan, P.G., Forbes, B.C., Kevan, S.M., and Behan-Pelletier, V. 1995. Vehicle tracks on high Arctic tundra: 1084
their effects on the soil, vegetation, and soil arthropods. J. Appl. Ecol. 32(3):655–667. 1085
Keim, J.L., DeWitt, P.D., Shopik, T., Fitzpatrick, J., and Lele, S.R. 2014. Understanding and mitigating the 1086
effects of linear features and snow condition on caribou predator-prey overlap in the Alberta Oil 1087
Sands. In 15th North American Caribou Workshop (May 12-16, 2014), Whitehorse, Y.T. 1088
Kurz, W.A, Shaw, C.H, Boisvenue, C., Stinson, G., Metsaranta, J., Leckie, D., Dyk, A., Smyth C., and Neilson 1089
E.T. 2013. Carbon in Canada’s boreal forest — A synthesis. Environmental Reviews, 21(4): 260-1090
292, https://doi.org/10.1139/er-2013-0041. 1091
Lankau, H., Bayne, E., and Machtans, C. 2013. Ovenbird (Seiurus aurocapilla) territory placement near 1092
seismic lines is influenced by forest regeneration and conspecific density. Avian Conserv. Ecol. 1093
8(1):5. Available from http://dx.doi.org/10.5751/ACE-00596-080105 [accessed 23 August 2017]. 1094
Latham, A.D.M., and Boutin, S. 2015. Impacts of utility and other industrial linear corridors on wildlife. In 1095
Handbook of road ecology. Edited by R. van der Ree, D.J. Smith, and C. Grilo. John Wiley & Sons, 1096
Oxford, UK. pp. 228–236. 1097
Page 47 of 60
https://mc06.manuscriptcentral.com/er-pubs
Environmental Reviews
Draft
48
Latham, A.D.M., Latham, M.C., Boyce, M.S., and Boutin, S. 2011a. Movement responses by wolves to 1098
industrial linear features and their effect on woodland caribou in northeastern Alberta. Ecol. 1099
Appl. 21(8):2854–2865. 1100
Latham, A.D.M., Latham, M.C., Knopff, K.H., Hebblewhite, M., and Boutin, S. 2013. Wolves, white-tailed 1101
deer, and beaver: implications of seasonal prey switching for woodland caribou declines. 1102
Ecography, 36:1276–1290. 1103
Latham, A.D.M., Latham, M.C., McCutchen, N.A., and Boutin, S. 2011b. Invading white-tailed deer 1104
change wolf–caribou dynamics in northeastern Alberta. J. Wildl. Manage. 75(1):204–212. 1105
Laurance, W.F., Ferreira, L.V., Rankin-de Merona, J.M., and Laurance, S.G. 1998. Rain forest 1106
fragmentation and the dynamics of Amazonian tree communities. Ecology, 79(6):2032–2040. 1107
Lawley, V., Lewis, M., Clarke, K., and Ostendorf, B. 2016. Site-based and remote sensing methods for 1108
monitoring indicators of vegetation condition: an Australian review. Ecol. Indic. 60:1273–1283. 1109
Lawrence, D.M., and Slater, A.G. 2005. A projection of severe near-surface permafrost degradation 1110
during the 21st century. Geophys. Res. Lett. 32:L24401. doi:10.1029/2005GL025080. 1111
Lee, P., and Boutin, S. 2006. Persistence and developmental transition of wide seismic lines in the 1112
western Boreal Plains of Canada. J. Environ. Manage. 78(3):240–250. 1113
Lieffers, V.J., Stadt, K.J., and Feng, Z. 2007. Free-to-grow regeneration standards are poorly linked to 1114
growth of spruce in boreal mixedwoods. For. Chron. 83(6):818–824. 1115
Lin, L., and Cao, M. 2009. Edge effects on soil seed banks and understory vegetation in subtropical and 1116
tropical forests in Yunnan, SW China. For. Ecol. Manage. 257(4):1344–1352. 1117
Linke, J., Franklin, S.E., Huettmann, F. and Stenhouse, G.B. 2005. Seismic cutlines, changing landscape 1118
metrics and grizzly bear landscape use in Alberta. Landscape Ecol. 20(7):811–826. 1119
MacFarlane, A.K. 2003. Vegetation response to seismic lines: edge effects and on-line succession. M.Sc 1120
thesis, Department of Renewable Resources, University of Alberta, Edmonton, Alta. 1121
Page 48 of 60
https://mc06.manuscriptcentral.com/er-pubs
Environmental Reviews
Draft
49
Marschall, M., and Proctor, M.C. 2004. Are bryophytes shade plants? Photosynthetic light responses and 1122
proportions of chlorophyll a, chlorophyll b and total carotenoids. Ann. Bot. 94(4):593–603. 1123
Machtans, C.S. 2006. Songbird response to seismic lines in the western boreal forest: a manipulative 1124
experiment. Can. J. Zool. 84(10):1421–1430. 1125
Machmer, M., and Steeger, C. 2002. Effectiveness monitoring guidelines for ecosystem 1126
restoration. Prepared for the Habitat Branch, B.C. Ministry of Water, Land and Air Protection. 1127
Pandion Ecological Research Ltd., Nelson, B.C. 1128
Mainwaring, A., Culler, D., Polastre, J., Szewczyk, R., and Anderson, J. 2002. Wireless sensor networks for 1129
habitat monitoring. In Proceedings of the 1 st ACM International Workshop on Wireless Sensor 1130
Networks and Applications, ACM, Atlanta, Georgia, USA pp. 88–97. 1131
McKenzie, H.W., Merrill, E.H., Spiteri, R.J., and Lewis, M.A. 2012. How linear features alter predator 1132
movement and the functional response. Interface Focus, 2(2):205–216. 1133
McLoughlin, P.D., Dzus, E., Wynes, B.O.B., and Boutin, S. 2003. Declines in populations of woodland 1134
caribou. J. Wildl. Manage. 67(4):755–761. 1135
Meunier, G., and Lavoie, C. 2012. Roads as corridors for invasive plant species: new evidence from 1136
smooth bedstraw (Galium mollugo). Invasive Plant Sci. Manage. 5(1):92–100. 1137
Munir, T.M., Xu, B., Perkins, M., and Strack, M. 2014. Responses of carbon dioxide flux and plant 1138
biomass to water table drawdown in a treed peatland in northern Alberta: a climate change 1139
perspective. Biogeosciences, 11(3):807–820. doi:10.5194/bg-11-807-2014. 1140
Neufeld, L.M. 2006. Spatial dynamics of wolves and woodland caribou in an industrial forest landscape 1141
in west-central Alberta. M.Sc. thesis, Department of Renewable Resources, University of 1142
Alberta, Edmonton, Alta. 1143
Ortega, Y.K., and Capen, D.E. 1999. Effects of forest roads on habitat quality for ovenbirds in a forested 1144
landscape. Auk, 16(4):937–946. 1145
Page 49 of 60
https://mc06.manuscriptcentral.com/er-pubs
Environmental Reviews
Draft
50
Pasher, J., Seed, E., and Duffe, J.2013.Development of boreal ecosystem anthropogenic disturbance 1146
layers for Canada based on 2008 to 2010 Landsat imagery. Can. J. Remote Sensing, 39(1):42–58. 1147
Pattison, C.A., Quinn, M.S., Dale, P. and Catterall, C.P. 2016. The landscape impact of linear seismic 1148
clearings for oil and gas development in boreal forest. Northwest Sci. 90(3):340–354. 1149
Pigeon, K.E., Anderson, M., MacNearney, D., Cranston, J., Stenhouse, G., and Finnegan, L. 2016. Toward 1150
the restoration of caribou habitat: understanding factors associated with human motorized use 1151
of legacy seismic lines. Environ. Manage. 58(5):821–832. doi 10.1007/s00267-016-0763-6 1152
Pohlman, C.L., Turton, S.M., and Goosem, M. 2007. Edge effects of linear canopy openings on tropical 1153
rain forest understory microclimate. Biotropica, 39(1):62–71. 1154
Porensky, L.M., and Young, T.P. 2013. Edge-effect interactions in fragmented and patchy 1155
landscapes. Conserv. Biol. 27(3):509–519. 1156
Pyper, M., Nishi, J., and McNeil, L. 2014. Linear feature restoration in caribou habitat: a summary of 1157
current practices and a roadmap for future programs. Canada’s Oil Sands Innovation Alliance, 1158
Calgary, Alta. Available from 1159
http://www.cosia.ca/uploads/documents/id24/COSIA_Linear_Feature_Restoration_Caribou_Ha1160
bitat.pdf [accessed 25 August 2017]. 1161
Quinton, W.L., Hayashi, M., and Chasmer, L.E. 2011. Permafrost-thaw-induced land-cover change in the 1162
Canadian subarctic: implications for water resources. Hydrol. Process. 25(1):152–158. 1163
Ray, J.C. 2014. Defining habitat restoration for boreal caribou in the context of national recovery: a 1164
discussion paper. Prepared for Environment and Climate Change Canada. Wildlife Conservation 1165
Society Canada, Toronto, Ont. 1166
Revel, R.D., Dougherty T.D., and Downing, D. J. 1984. Forest growth and revegetation along seismic 1167
lines. The University of Calgary Press, Calgary, Alta. 1168
Page 50 of 60
https://mc06.manuscriptcentral.com/er-pubs
Environmental Reviews
Draft
51
Riva, F., Acorn, J.H., and Nielson, S.E. 2018. Localized disturbances from oil sands developments increase 1169
butterfly diversity and abundance in Alberta's boreal forests. Biological Conservation 217: 173–1170
180. 1171
Schneider, R.R. 2002. Alternative futures: Alberta’s boreal forest at the crossroads. Federation of Alberta 1172
Naturalists and Alberta Centre for Boreal Research, Edmonton, Alta. 1173
Schneider, R., Stelfox, J.B., Boutin, S. and Wasel, S. 2003. Managing the cumulative impacts of land uses 1174
in the Western Canadian Sedimentary Basin: a modeling approach. Conservation Ecology, 7(1). 1175
Schulp, C.J.E., van Teeffelen, A.J.A., Tucker, G., and Verburg, P.H. 2016. A quantitative assessment of 1176
policy options for no net loss of biodiversity and ecosystem services in the European Union. 1177
Land Use Policy, 57:151–163. 1178
Schuur, E.A., Vogel, J.G., Crummer, K.G., Lee, H., Sickman, J.O., and Osterkamp, T.E. 2009. The effect of 1179
permafrost thaw on old carbon release and net carbon exchange from tundra. Nature, 1180
459(7246):556–559. 1181
Serrouya, R., McLellan, B.N., van Oort, H., Mowat, G. and Boutin, S., 2017. Experimental moose 1182
reduction lowers wolf density and stops decline of endangered caribou. Peer J, 5, p.e3736. 1183
Severson-Baker, C. 2006. Seismic exploration: a primer [online]. The Pembina Institute, Drayton Valley, 1184
Alta. Available from https://www.pembina.org/reports/nps_Seismic.pdf [accessed 25 August 1185
2017]. 1186
Smith, S. 2011. Trends in permafrost conditions and ecology in northern Canada. Canadian biodiversity: 1187
ecosystem status and trends 2010. Canadian Council of Resource Ministers, Ottawa, Ont. Tech. 1188
Themat. Rep. No. 9. 1189
Starr, G., Oberbauer, S.F., and Ahlquist, L.E. 2008. The photosynthetic response of Alaskan tundra plants 1190
to increased season length and soil warming. Arctic Antarct. Alp. Res. 40(1):181–191. 1191
Page 51 of 60
https://mc06.manuscriptcentral.com/er-pubs
Environmental Reviews
Draft
52
Strack, M., Keith, A.M., and Xu, B. 2014. Growing season carbon dioxide and methane exchange at a 1192
restored peatland on the Western Boreal Plain. Ecol. Eng. 64:231–239. 1193
Strack, M., Softa D., Bird, M., Xu, B. 2017. Impact of winter roads on boreal peatland carbon exchange. 1194
Glob Change Biol. 00:1–12. https://doi.org/10.1111/gcb.13844 1195
Sustainable Forest Management Network (SFMN) Conference : science and practice: sustaining the 1196
boreal forest, February 14-17, 1999, Edmonton, Alberta. Sustainable Forest Management 1197
Network, University of Alberta, Edmonton, Alberta. 816 p. 1198
Tigner, J., Bayne, E.M., and Boutin, S. 2014. Black bear use of seismic lines in Northern Canada. J. Wildl. 1199
Manage. 78(2):282–292. 1200
Tigner, J., Bayne, E.M., and Boutin, S. 2015. American marten respond to seismic lines in Northern 1201
Canada at two spatial scales. PloS One, 10(3):e0118720. doi:10.1371/journal.pone.0118720. 1202
Timoney, K., and Lee, P. 2001. Environmental management in resource-rich Alberta, Canada: first world 1203
jurisdiction, third world analogue? J. Environ. Manage. 63:387–405. 1204
US Energy Information Administration. 2017. Frequently asked questions. Available from 1205
https://www.eia.gov/tools/faqs/faq.php?id=58&t=8 [accessed 22 January 2018). 1206
van Rensen, C.K., Nielsen, S.E., White, B., Vinge, T., and Lieffers, V.J. 2015. Natural regeneration of forest 1207
vegetation on legacy seismic lines in boreal habitats in Alberta’s oil sands region. Biol. Conserv. 1208
184:127–135. 1209
Vitt, D.H., Achuff, P., and Andrus, R.E. 1975. The vegetation and chemical properties of patterned fens in 1210
the Swan Hills, north central Alberta. Can. J. Bot. 53(23):2776–2795. 1211
Walker, T.N., Garnett, M.H., Ward, S.E., Oakley, S., Bardgett, R.D., and Ostle, N.J. 2016. Vascular plants 1212
promote ancient peatland carbon loss with climate warming. Glob. Change Biol. 22:1880–1889. 1213
doi: 10.1111/gcb.13213. 1214
Page 52 of 60
https://mc06.manuscriptcentral.com/er-pubs
Environmental Reviews
Draft
53
Wasser, S.K., Keim, J.L., Taper, M.L., and Lele, S.R. 2011. The influences of wolf predation, habitat loss, 1215
and human activity on caribou and moose in the Alberta oil sands. Front. Ecol. Environ. 1216
9(10):546–551. 1217
Whittington, J., Hebblewhite, M., DeCesare, N.J., Neufeld, L., Bradley, M., Wilmshurst, J., and Musiani, 1218
M. 2011. Caribou encounters with wolves increase near roads and trails: a time-to-event 1219
approach. J. Appl. Ecol. 48(6):1535-1542. 1220
Williams, T.J., and Quinton, W.L. 2013. Modelling incoming radiation on a linear disturbance and its 1221
impact on the ground thermal regime in discontinuous permafrost. Hydrol. 1222
Process. 27(13):1854–1865. 1223
Williams, T.J., Quinton, W.L., and Baltzer, J.L. 2013. Linear disturbances on discontinuous permafrost: 1224
implications for thaw-induced changes to land cover and drainage patterns. Environ. Res. Lett. 1225
8(2):025006. doi:10.1088/1748-9326/8/2/025006 1226
Williams-Linera, G. 1990. Vegetation structure and environmental conditions of forest edges in 1227
Panama. J. Ecol. 78(2):356–373. 1228
Wilson, T.L. 2011. Effects of seismic exploration on pygmy rabbits. Nat. Resour. Environ. Issues, 17:55. 1229
Wulder, M., and Franklin, S.E. (Editors). 2012. Remote sensing of forest environments: concepts and 1230
case studies. Springer Science & Business Media, New York. Available from 1231
https://books.google.com/books?id=zIvuBwAAQBAJ&pgis=1 [accessed 27 October 2017]. 1232
Yeh, S., Jordaan, S.M., Brandt, A.R., Turetsky, M.R., Spatari, S., and Keith, D.W. 2010. Land use 1233
greenhouse gas emissions from conventional oil production and oil sands. Environ. Sci. Technol. 1234
44(22):8766–8772. 1235
Yukon Government. 2006. “Oil & Gas Best Management Practices – Seismic Exploration.” Energy, Mines 1236
and Resources, Yukon Government. http://www.emr.gov.yk.ca/oilandgas/pdf/bmp_seismic.pdf. 1237
Page 53 of 60
https://mc06.manuscriptcentral.com/er-pubs
Environmental Reviews
Draft
54
Zahawi, R.A., Dandois, J.P., Holl, K.D., Nadwodny, D., Reid, J.L., and Ellis, E.C. 2015. Using lightweight 1238
unmanned aerial vehicles to monitor tropical forest recovery. Biol. Conserv. 186:287–295. 1239
Zhang, X., Vincent, L.A., Hogg, W.D., and Niitsoo, A. 2000. Temperature and precipitation trends in 1240
Canada during the 20th century. Atmos. Ocean, 38(3):395–429. 1241
Zhang, Y., Chen, W., and Riseborough, D.W. 2008. Disequilibrium response of permafrost thaw to 1242
climate warming in Canada over 1850–2100. Geophys. Res. Lett. 35(2):L02502. 1243
doi:10.1029/2007GL032117. 1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
Page 54 of 60
https://mc06.manuscriptcentral.com/er-pubs
Environmental Reviews
Draft
55
Figure 1. Seismic lines from above: (a) density of seismic lines in some woodland caribou ranges in 1262
northeastern Alberta (from Alberta Biodiversity Monitoring Institute 2016); (b) satellite image of an area 1263
corresponding to the high-density cells in Fig. 1a (Image was created using ArcGIS® software by Esri. 1264
ArcGIS® and ArcMap™ are the intellectual property of Esri and are used herein under license. Copyright 1265
© Esri. All rights reserved. (www.esri.com)); (c) close-up from a drone of the area enclosed by red 1266
rectangle in Fig. 1b (Photograph by Guillermo Castilla). 1267
1268
Figure 2. Examples of seismic lines: (a) conventional seismic line in coniferous boreal upland forest; (b) 1269
conventional seismic line in boreal peatlands; (c) low-impact seismic line in coniferous boreal upland 1270
forest. (Photographs by Anna Dabros). 1271
1272
Figure 3. Types of machinery used in the construction of seismic lines: (a) bulldozer from the 1950s 1273
(Edward Browning URL: https://classicdozers.files.wordpress.com/2013/03/caterpillar-no-7a-blade-on-1274
a-d-7-17a-tractor-edgar-browning-image.jpg); 1275
(b) implements to reduce or avoid scuffing the soil layer (b1, mushroom shoe; b2, smear blade) (GNWT 1276
2012); (c) modern mulcher http://ironwolf.com/products/mulcher/; (d) envirodrill 1277
(http://www.coredrillingcorp.com/). 1278
1279
Page 55 of 60
https://mc06.manuscriptcentral.com/er-pubs
Environmental Reviews
Draft
Figure 1.
a b
c
Page 56 of 60
https://mc06.manuscriptcentral.com/er-pubs
Environmental Reviews
Draft
Figure 2.
a
b c
Page 57 of 60
https://mc06.manuscriptcentral.com/er-pubs
Environmental Reviews
Draft
Figure 3.
a
b b
c d
Page 58 of 60
https://mc06.manuscriptcentral.com/er-pubs
Environmental Reviews
Draft
1
Table 1. An inventory of current seismic line restoration techniques.
Treatment What is it? Why would you use it? Where would you use it?
Mounding
An excavator is used to
dig holes and place the
soil beside the hole
creating an elevated
mound.
Mounds create an elevated
microsite that increases soil
temperature and improves
growing conditions for natural
regeneration and/or planted
seedlings.
Mounds can help create an
access barrier for human use
and may impede predator
movement on lines.
Lowlands with high water
tables (moisture concerns).
Dry stands to improve
moisture availability (pooling
of water in mound holes).
Uplands to address
competition concerns (e.g.,
grasses).
Screefing
An excavator or other
implement removes
the organic layer,
exposing a mineral soil
microsite.
Can be used in areas where
organic layers would inhibit
seed germination. Can also
help create pockets of
moisture in dry sites.
May promote tree suckering.
Generally used on xeric sites
with thick duff or litter layers.
Ripping
A bulldozer with either
ripping teeth or a
specialized plow, used
to decompact soil.
Reduces site compaction,
improves moisture
availability, soil aeration and
potential for root
development.
Generally used on upland sites
with soil compaction issues.
Rollback and
coarse woody
material
Woody materials from
beside the line, or from
nearby operations, are
placed on the line.
Creates microsites for
vegetation establishment and
protection of seedlings
(natural and planted).
Creates a human access
barrier when applied at high
enough volumes.
May impede predator
movement.
Anywhere microsites would
help regeneration or where
access management is
required.
Tree felling or
tree hinging
Trees adjacent to the
seismic line are felled
across it.
Creates microsites for
vegetation establishment and
protection of seedlings
(natural and planted).
Creates a human access
barrier when applied at high
enough volumes.
May impede predator
movement.
Any sites where microsites
would benefit regeneration or
where access management is
required.
Page 59 of 60
https://mc06.manuscriptcentral.com/er-pubs
Environmental Reviews
Draft
2
Treatment What is it? Why would you use it? Where would you use it?
Tree tipping
A process by which
trees are pulled over
using winches or heavy
equipment.
Felling trees results in rapid
loss of needles. Tree tipping
maintains root contact with
soils and may extend the life
of the tree while still creating
a line-of-sight and movement
barrier for wolves and
humans.
Any sites where microsites
would benefit regeneration or
where access management is
required to reduce human
access and predator
movement.
Tree transplants
Established trees
adjacent to the
treatment lines are
excavated and moved
onto treatment lines.
Generally used in situations
where operators wish to
establish immediate tree
cover on a line.
Generally restricted to wet
areas where the root ball can
be excavated with minimal
damage to the root structure.
Summer planting
Seedlings are planted
to encourage
regeneration.
Can help ensure desirable
species mixes.
Puts vegetation on a long-
term recovery trajectory to a
restored condition.
Any sites where improving
regeneration is desirable.
Often used in combination
with site preparation.
Wetlands can be difficult to
plant in summer (access
challenges).
Winter planting
Seedlings are planted
to encourage
regeneration.
Establishes conifer cover on
sites and puts vegetation on a
long-term recovery trajectory
to a restored condition.
Generally used in treed
wetlands where site
preparation (mounding) has
occurred. Enables planting of
wetlands when access is
possible (i.e., frozen ground
conditions).
Seeding
Seeds are spread on
exposed microsites to
facilitate tree
recruitment.
Can reduce project costs and
in some cases may improve
tree establishment by
allowing trees to establish on
the most desirable microsites
as opposed to relying on a
planted tree plug.
Sites with sufficient exposed
microsites to enable seed
germination.
Natural
regeneration
Exposed microsites are
created and rely on
seed influx from the
adjacent stand.
Can reduce project costs and
in some cases may improve
tree establishment by
allowing trees to establish on
the most desirable microsites
as opposed to relying on a
planted tree plug.
Sites with sufficient exposed
microsites to enable seed
germination and with sufficient
seed sources of desired species
(e.g., white spruce) available
adjacent to the treated line.
Page 60 of 60
https://mc06.manuscriptcentral.com/er-pubs
Environmental Reviews