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Received: 8 September 2016 Revised: 22 February 2017 Accepted: 5 March 2017 DOI: 10.1002/ece3.2941
ORIGINAL RESEARCH
Reindeer habitat use in relation to two small wind farms, during preconstruction, construction, and operation Anna Skarin1
| Moudud Alam2
1
Department of Animal Nutrition and Management, Swedish University of Agricultural Sciences, Uppsala, Sweden 2
Section of Statistics, School of Technology and Business Studies, Dalarna University, Falun, Sweden Correspondence Anna Skarin, Department of Animal Nutrition and Management, Swedish University of Agricultural Sciences, Uppsala, Sweden. Email: [email protected] Funding information Swedish Energy Agency; Vindval, Grant/Award Number: 31940-1 and 31940-2
Abstract Worldwide there is a rush toward wind power development and its associated infrastructure. In Fennoscandia, large-scale wind farms comprising several hundred windmills are currently built in important grazing ranges used for Sámi reindeer husbandry. In this study, reindeer habitat use was assessed using reindeer fecal pellet group counts in relation to two relatively small wind farms, with 8 and 10 turbines, respectively. In 2009, 1,315 15-m2 plots were established and pellet groups were counted and cleaned from the plots. This was repeated once a year in May, during preconstruction, construction, and operation of the wind farms, covering 6 years (2009–2014) of reindeer habitat use in the area. We modeled the presence/absence of any pellets in a plot at both the local (wind farm site) and regional (reindeer calving to autumn range) scale with a hierarchical logistic regression, where spatial correlation was accounted for via random effects, using vegetation type, and the interaction between distance to wind turbine and time period as predictor variables. Our results revealed an absolute reduction in pellet groups by 66% and 86% around each wind farm, respectively, at local scale and by 61% at regional scale during the operation phase compared to the preconstruction phase. At the regional, scale habitat use declined close to the turbines in the same comparison. However, at the local scale, we observed increased habitat use close to the wind turbines at one of the wind farms during the operation phase. This may be explained by continued use of an important migration route close to the wind farm. The reduced use at the regional scale nevertheless suggests that there may be an overall avoidance of both wind farms during operation, but further studies of reindeer movement and behavior are needed to gain a better understanding of the mechanisms behind this suggested avoidance. KEYWORDS
anthropogenic disturbance, before after design, pellet group count, Rangifer, renewable energy development, Sámi reindeer husbandry, spatial correlation
1 | INTRODUCTION
reindeer husbandry system in Northern Europe. The forest has been
The boreal forest in Fennoscandia represents an important grazing
such as mining and hydro power, over the last century (Herrmann
resource for reindeer (Rangifer tarandus tarandus) within the Sámi
et al., 2014; Sandström et al., 2016). More recently, there has been a
exposed to major changes due to forestry and other exploitation,
This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited. © 2017 The Authors. Ecology and Evolution published by John Wiley & Sons Ltd. 3870 | www.ecolevol.org
Ecology and Evolution. 2017;7:3870–3882.
|
3871
SKARIN and ALAM
massive increase in the planning and construction of large wind farms
on the reindeer (Vistnes & Nellemann, 2008). This means that regional
in the forest area, comprising several hundred windmills together with
and long-term studies are required to safeguard against underestimat-
their associated infrastructure of roads and power lines. For exam-
ing the most important effects and to capture how the free ranging
ple, in the four northern counties of Sweden, there are currently 902
herded reindeer react to changes in the landscape. Nonetheless, a
wind turbines in place, another 1,588 are planned and applications
drawback when increasing the scale of a study is the problem of con-
have been submitted for a further 2,143 (www.vindbrukskollen.se,
founding effects among the landscape metrics, which can potentially
December 2016), with little knowledge of the possible adverse effects
enhance or reduce the effect of a disturbance (Clevenger & Waltho,
on reindeer husbandry and the habitat use and migration of free-
2005). Therefore, it is necessary to select the explanatory variables
ranging reindeer, as well as other species.
carefully and thus reduce correlations between them, or to evaluate
Wind turbines usually have a running phase of 20–25 years. An increased knowledge of the impacts on reindeer habitat use is critical
ways to remove correlations before interpreting the results of any study (Graham, 2003).
in order to mitigate those impacts from work already in the planning
A common and often recommend tool to evaluate environmen-
phase (Northrup & Wittemyer, 2013). In addition, disturbance asso-
tal impact and ways to remove distortions due to correlations is the
ciated with the human activity within the wind farm, as well as noise
so-called Before-After-Control-Impact (BACI) experimental design
from wind turbines, might disturb animals, hindering vocal communica-
(Kuvlesky et al., 2007; Strickland et al., 2011). In such a design, two
tion and their ability to hear predators (Biedenweg, Parsons, Fleming,
parallel study areas are evaluated before and after development: One
& Blumstein, 2011; Rabin, Coss, & Owings, 2006). Furthermore, prey
where the development takes place and another similar area that
animals like reindeer react to movements in their sight (Favreau,
serves as a control. However, two calving areas, for example, might be
Goldizen, & Pays, 2010; Heesy, 2004) and may, therefore, react to the
difficult to compare at the regional scale because of large variations
movement of the turbine blades. To date, three studies have exam-
in landscape conditions (including other infrastructure) between dif-
ined the effects of wind farm construction and operation in relation
ferent reindeer herding communities. An alternative to BACI design
to reindeer habitat use and these found limited to large effects of the
is to perform a before after (BA) study over an area large enough to
wind farms (Colman et al., 2012, 2013; Skarin et al., 2015). Studies of
capture the effects at the regional scale, and at the same time try to
reindeer habitat selection in relation to wind farm development from
control for the differences between years that do not depend on the
the boreal forest landscape are scarce (cf. Skarin et al., 2015).
development.
Reindeer are opportunistic feeders constantly moving over large
Pellet group counts, as a technique to survey an animal’s habitat
areas while feeding, following the vegetation phenology during
use, have the advantage that the overall animal abundance over sev-
the snow-free season to exploit early stages of plant growth (e.g.,
eral months is captured at a large spatial scale, based on a concentrated
Iversen et al., 2014; Skarin, Danell, Bergstrom, & Moen, 2010). The
recording effort (Marques et al., 2001). A large number of habitat
free-ranging reindeer associated with Sámi reindeer husbandry in
selection studies on large herbivores (including reindeer) have used
Fennoscandia roam freely for most of the year, especially during the
fecal pellet group counts to collect data on habitat use (e.g., Guillet
snow-free season when the herders only gather the reindeer for calf
et al., 1995; Harkonen & Heikkila, 1999; Mansson, Hauser, Andren,
marking in the middle of the summer (Skarin et al., 2010). In the win-
& Possingham, 2011; Neff, 1968; Quayle & Kershaw, 1996; Skarin,
ter and during migrations between summer and winter ranges, they
2007). However, these recent works on the analysis of habitat pref-
may be more constrained in their movements by herders’ every-day
erences failed to address the issue of spatial correlation among their
actions.
pellet group count observations in their analysis. Failing to account
Studying habitat selection by herbivores, such as reindeer, demands
for zero-inflation and correlation can induce substantial bias in the
a hierarchical or multiscale approach to minimize the risk of missing
estimates of effects (Kassahun et al., 2014) and invalidate any statis-
important behavioral responses to factors that have a different impact
tical inference, due to the violation of the mean−variance relationship
at different scales (Northrup, Anderson, Hooten, & Wittemyer, 2016;
imposed by ordinary generalized linear models, for example, binomial
Senft et al., 1987; Skarin & Åhman, 2014). Noninteractive factors, for
and Poisson’s models (Kassahun et al., 2014; Lee et al., 2016). Using
example, barriers, have an impact on habitat selection at the large geo-
a suitable hierarchical generalized linear model (Lee & Nelder, 1996)
graphical scale and may limit selection at local scales (Northrup et al.,
with spatially correlated random effects, for example, a spatial Poisson
2016; Senft et al., 1987). Earlier studies of reindeer and caribou show
(Lee et al., 2016) or a binomial model, we may be able to overcome
clear patterns in avoiding infrastructure and human activity over rela-
this problem.
tively large distances, sometimes several kilometers (e.g., Beyer et al.,
The aim of this study was to evaluate whether reindeer habitat
2016; Johnson, Ehlers, & Seip, 2015; Skarin & Åhman, 2014; Vistnes
use, measured by fecal pellet group abundance, in the vicinity of the
& Nellemann, 2008). Vistnes and Nellemann (2008) found that studies
wind farms was lower during the construction and operation phase of
examining the effect of disturbance on reindeer and caribou within
two relatively small wind farms (8 and 10 wind turbines, respectively)
2 km of the source and/or during short time periods often did not re-
compared to the period before construction. Because the reindeer are
veal any effect of disturbance. The majority of the studies in which the
likely to be annoyed by the sound and sight of the wind turbines as
effects over distances greater than 2 km and/or during a longer time
well as the increased human activities (e.g., sound from vehicles asso-
period were considered, revealed negative effects of the disturbance
ciated with wind farm construction and maintenance), we hypothesize
|
3872
SKARIN and ALAM
that they would avoid or decrease their usage of the areas nearby the
Sweden (Figure 1). The study area was used by a part of the total herd:
wind farm during the construction and operation phases compared
approximately 1,200 female reindeer and their calves (the total number
to the preconstruction phase. This hypothesis was tested using a BA
of female reindeer in the whole herd ranged between 4,144, and 4,854
design (Strickland et al., 2011). Overall impact of the wind farm con-
over the study years). Every year in April, migration took place (“by
struction and operation phase on reindeer habitat use was evaluated
foot” in all years except 2015, when the reindeer were moved with
at both regional (reindeer range used from calving to autumn, within
trucks), with the reindeer herd moving from the winter ranges in the
15 km of the wind farm) and local (wind farm mountains within 2 km
east to the summer ranges in the west. After migration, the reindeer
from wind turbines) scales using pellet group counts in relation to dis-
were released into the study area (see arrows in Figure 1) at the begin-
tance to wind turbine in association with time period, after controlling
ning of May (2 May 2009, 10 May 2010 and 2011, and 1 May 2015;
for the possible confounding effects, and spatial correlation.
for the other years, we do not have an exact date of arrival). The reindeer used the area primarily during the calving season and then moved
2 | MATERIAL AND METHODS 2.1 | Study area
in and out of the area during the whole snow-free season until late autumn when they were moved back to the winter ranges. At the end of June, reindeer were gathered by the herders for calf marking and moved to the closest corral, thus redistributing the reindeer to some
The study was conducted in and around the two wind farms near
extent. In the early autumn (from the end of August), reindeer concen-
to each other, on Storliden mountain and Jokkmokksliden mountain
trated their activity toward the southern side of Storliden before they
(where eight and 10 wind turbines, respectively, were constructed
moved out of the area freely or because of the herders’ action.
in 2010–2011), located in the calving and postcalving ranges of the
The study area is characterized by a boreal forest landscape, in-
Malå forest reindeer herding community (65°14′, 18°58′) in northern
terspersed with mires, lakes and hills or smaller mountains, with the
F I G U R E 1 Map showing part of the calving area of the Malå reindeer herding community and the study area, with local scale pellet group count plots marked with red dots, the regional scale pellet group counts marked with brown dots, and the important reindeer migration routes in the herding community marked in yellow. Arrows show approximate sites where the reindeer were let out into the calving ranges after the migration “by foot” controlled by the herders ©Lantmäteriet i1204/764
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3873
SKARIN and ALAM
forested land comprising old growth forest, clear cuts, and plantations.
plots were positioned and marked with a wooden stick, and after the
The whole study area is a managed forest; when the trees are 70 years), 600 m north and
pellet groups being hidden by understory vegetation, that is, at the end
1200 m west of the wind farm were clear cut in May 2012 and in July
of the calving season each year. Thus, the inventory in 2010 mainly
2013, respectively.
represented the reindeer use prior to the construction of the wind farm and the first 15 days of the construction work at Jokkmokksliden
2.2 | Wind farm construction site and existing infrastructure
during calving and was treated as representative of reindeer use during the “preconstruction” phase. The inventory in 2011 solely represented the construction phase. The inventory in 2012 covered both
The year 2009 was defined as the predevelopment year (hereafter re-
part of the construction phase in 2011 and the operation phase in May
ferred to as the “pre-construction” phase), during which the area had
2012, and thus represented a mix of construction and operation phase
existing infrastructure such as a road network, power lines, and an un-
(Table 1) plus in addition the forest activity at Storliden in May 2012.
derground mine on the north side of Storliden (this ceased working in
However, to keep things simple and to have a large enough sample to
2008). Construction work started on 10 May 2010 at Jokkmokksliden,
assure stability of the inference on the effects of the different phases,
and on 1 June 2010 at Storliden. To access the wind farms, 22 km of
we treat the inventories from 2011 and 2012 as representative of the
roads was constructed, with 8.5 km of 36 kV power lines connecting
construction period. Because of the overlap of data collection in 2012
to the existing power grid via the new utility station built in between
between operation and construction phase, conclusions drawn on the
the wind farms. The full infrastructure at Jokkmokksliden, was devel-
effect of construction period should be regarded as a mixed effect
oped during 2010 and the first five wind turbines were constructed,
of construction and operation (with most weight being given to the
with five more turbines being erected in 2011. At Storliden, the road
construction period). The inventories from 2013, 2014, and 2015 rep-
network and power lines were established in 2010 and the turbines
resented the operation phase, except for the forestry activity in July
were put in place in 2011. All turbines started to generate electricity
2013. It is generally believed that there is some random variation in
in November 2011. The years 2010 and 2011 are hereafter referred
habitat use by reindeer between years (Nicholson et al., 2016), which
to as the “construction” phase, as development continued throughout.
was also seen in the initial analysis of the data (Figure 2); therefore, it
The years after construction (2012–2015) are here referred to as the
makes sense to average the usage over a number of years to get stable
“operation” phase, as the wind turbines were running.
estimate of the effects of the wind farm. The study followed a point transect survey design (Buckland et al., 2001) at the local scale within 2 km of the wind farms, covering 15 km2
2.3 | Pellet group counts
around each wind farm, and at the regional scale within 15 km of the
The fecal pellet group count, used as a proxy to measure habitat use
wind farm, covering 250 km2, the core of the reindeer calving range
by the reindeer, was conducted every year (2010–2015), over a pe-
(Figure 1). In 2009, 1,315 plots were inventoried, and in the follow-
riod of 4–9 days between 24 May and 8 June (Table 1). The pellet
ing years, 1,162–1,248 plots were inventoried. Each plot was 15 m2
groups were counted using the fecal accumulation rate in 2010–2015
(radius = 2.18 m). At the local scale, the distance between transects
(Campbell, Swanson, & Sales, 2004; Skarin, 2007). Thus, in 2009, the
was 300 m and the distance between each plot on the transects was
T A B L E 1 Date of pellet group counts in the Malå reindeer herding community, including phases for Storliden and Jokkmokksliden wind farm development and how this corresponded to reindeer use of the area (note that reindeer did not use the area during the winter seasons from November to April) Phase of wind farm development Inventory not used in statistical analysis
Date for pellet group count 1–9/6 2009
Date of reindeer use represented by each count May in 2009 and 2008 and prior to this depending on pellet group decay rate within each vegetation type
Preconstruction and 15 days construction
28/5–1/6 2010
10/6 2009–27/5 2010
Construction
23/5–26/5 2011
2/6 2010–22/5 2011
Construction and 30 days operation
28/5–1/6 2012
27/5 2011–27/5 2012
Operation
27/5–2/6 2013
2/6 2012–26/5 2013
Operation
2/6–8/6 2014
3/6 2013–1/6 2014
Operation
25/5–29/5 2015
9/6 2014–24/5 2015
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SKARIN and ALAM
3874
2012
2013
2014
2015
2011
2012
2013
Year
Storliden
Jokkmokksliden
2015
2014
2015
1.0
2014
2010
2011
2012
2013
2014
2015
Year
0.8 0.5
0.6
0.7
Rel. Freq.
0.9
0.9 0.8 0.7 0.5
2010
Year
0.6
Rel. Freq.
0.8
0.9 2011
0.5
2010
1.0
0.5
0.6
0.7
0
0.7
1
Rel. Freq.
0.8
Pellet−group Count >2
0.6
Rel. Freq.
0.9
1.0
Region
1.0
Combined
2010
2011
2012
2013
Year
F I G U R E 2 Bar graphs of the relative frequency of pellet group counts within each study year for all data combined, data from the count at the region scale, and data from the count at the local scale from Storliden and from Jokkmokksliden (2010 – Preconstruction, 2011 and 2012— Construction, and 2012–2014—Operation)
100 m. At the regional scale, the plots were placed along the sides of
variables included were vegetation type, elevation, slope, minimum
29 1 × 1 km squares, with 20 plots every 200 m along the perimeter
distance to large (>5 m) and small (5 m stem length) Clear cuts (
|
Received: 8 September 2016 Revised: 22 February 2017 Accepted: 5 March 2017 DOI: 10.1002/ece3.2941
ORIGINAL RESEARCH
Reindeer habitat use in relation to two small wind farms, during preconstruction, construction, and operation Anna Skarin1
| Moudud Alam2
1
Department of Animal Nutrition and Management, Swedish University of Agricultural Sciences, Uppsala, Sweden 2
Section of Statistics, School of Technology and Business Studies, Dalarna University, Falun, Sweden Correspondence Anna Skarin, Department of Animal Nutrition and Management, Swedish University of Agricultural Sciences, Uppsala, Sweden. Email: [email protected] Funding information Swedish Energy Agency; Vindval, Grant/Award Number: 31940-1 and 31940-2
Abstract Worldwide there is a rush toward wind power development and its associated infrastructure. In Fennoscandia, large-scale wind farms comprising several hundred windmills are currently built in important grazing ranges used for Sámi reindeer husbandry. In this study, reindeer habitat use was assessed using reindeer fecal pellet group counts in relation to two relatively small wind farms, with 8 and 10 turbines, respectively. In 2009, 1,315 15-m2 plots were established and pellet groups were counted and cleaned from the plots. This was repeated once a year in May, during preconstruction, construction, and operation of the wind farms, covering 6 years (2009–2014) of reindeer habitat use in the area. We modeled the presence/absence of any pellets in a plot at both the local (wind farm site) and regional (reindeer calving to autumn range) scale with a hierarchical logistic regression, where spatial correlation was accounted for via random effects, using vegetation type, and the interaction between distance to wind turbine and time period as predictor variables. Our results revealed an absolute reduction in pellet groups by 66% and 86% around each wind farm, respectively, at local scale and by 61% at regional scale during the operation phase compared to the preconstruction phase. At the regional, scale habitat use declined close to the turbines in the same comparison. However, at the local scale, we observed increased habitat use close to the wind turbines at one of the wind farms during the operation phase. This may be explained by continued use of an important migration route close to the wind farm. The reduced use at the regional scale nevertheless suggests that there may be an overall avoidance of both wind farms during operation, but further studies of reindeer movement and behavior are needed to gain a better understanding of the mechanisms behind this suggested avoidance. KEYWORDS
anthropogenic disturbance, before after design, pellet group count, Rangifer, renewable energy development, Sámi reindeer husbandry, spatial correlation
1 | INTRODUCTION
reindeer husbandry system in Northern Europe. The forest has been
The boreal forest in Fennoscandia represents an important grazing
such as mining and hydro power, over the last century (Herrmann
resource for reindeer (Rangifer tarandus tarandus) within the Sámi
et al., 2014; Sandström et al., 2016). More recently, there has been a
exposed to major changes due to forestry and other exploitation,
This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited. © 2017 The Authors. Ecology and Evolution published by John Wiley & Sons Ltd. 3870 | www.ecolevol.org
Ecology and Evolution. 2017;7:3870–3882.
|
3871
SKARIN and ALAM
massive increase in the planning and construction of large wind farms
on the reindeer (Vistnes & Nellemann, 2008). This means that regional
in the forest area, comprising several hundred windmills together with
and long-term studies are required to safeguard against underestimat-
their associated infrastructure of roads and power lines. For exam-
ing the most important effects and to capture how the free ranging
ple, in the four northern counties of Sweden, there are currently 902
herded reindeer react to changes in the landscape. Nonetheless, a
wind turbines in place, another 1,588 are planned and applications
drawback when increasing the scale of a study is the problem of con-
have been submitted for a further 2,143 (www.vindbrukskollen.se,
founding effects among the landscape metrics, which can potentially
December 2016), with little knowledge of the possible adverse effects
enhance or reduce the effect of a disturbance (Clevenger & Waltho,
on reindeer husbandry and the habitat use and migration of free-
2005). Therefore, it is necessary to select the explanatory variables
ranging reindeer, as well as other species.
carefully and thus reduce correlations between them, or to evaluate
Wind turbines usually have a running phase of 20–25 years. An increased knowledge of the impacts on reindeer habitat use is critical
ways to remove correlations before interpreting the results of any study (Graham, 2003).
in order to mitigate those impacts from work already in the planning
A common and often recommend tool to evaluate environmen-
phase (Northrup & Wittemyer, 2013). In addition, disturbance asso-
tal impact and ways to remove distortions due to correlations is the
ciated with the human activity within the wind farm, as well as noise
so-called Before-After-Control-Impact (BACI) experimental design
from wind turbines, might disturb animals, hindering vocal communica-
(Kuvlesky et al., 2007; Strickland et al., 2011). In such a design, two
tion and their ability to hear predators (Biedenweg, Parsons, Fleming,
parallel study areas are evaluated before and after development: One
& Blumstein, 2011; Rabin, Coss, & Owings, 2006). Furthermore, prey
where the development takes place and another similar area that
animals like reindeer react to movements in their sight (Favreau,
serves as a control. However, two calving areas, for example, might be
Goldizen, & Pays, 2010; Heesy, 2004) and may, therefore, react to the
difficult to compare at the regional scale because of large variations
movement of the turbine blades. To date, three studies have exam-
in landscape conditions (including other infrastructure) between dif-
ined the effects of wind farm construction and operation in relation
ferent reindeer herding communities. An alternative to BACI design
to reindeer habitat use and these found limited to large effects of the
is to perform a before after (BA) study over an area large enough to
wind farms (Colman et al., 2012, 2013; Skarin et al., 2015). Studies of
capture the effects at the regional scale, and at the same time try to
reindeer habitat selection in relation to wind farm development from
control for the differences between years that do not depend on the
the boreal forest landscape are scarce (cf. Skarin et al., 2015).
development.
Reindeer are opportunistic feeders constantly moving over large
Pellet group counts, as a technique to survey an animal’s habitat
areas while feeding, following the vegetation phenology during
use, have the advantage that the overall animal abundance over sev-
the snow-free season to exploit early stages of plant growth (e.g.,
eral months is captured at a large spatial scale, based on a concentrated
Iversen et al., 2014; Skarin, Danell, Bergstrom, & Moen, 2010). The
recording effort (Marques et al., 2001). A large number of habitat
free-ranging reindeer associated with Sámi reindeer husbandry in
selection studies on large herbivores (including reindeer) have used
Fennoscandia roam freely for most of the year, especially during the
fecal pellet group counts to collect data on habitat use (e.g., Guillet
snow-free season when the herders only gather the reindeer for calf
et al., 1995; Harkonen & Heikkila, 1999; Mansson, Hauser, Andren,
marking in the middle of the summer (Skarin et al., 2010). In the win-
& Possingham, 2011; Neff, 1968; Quayle & Kershaw, 1996; Skarin,
ter and during migrations between summer and winter ranges, they
2007). However, these recent works on the analysis of habitat pref-
may be more constrained in their movements by herders’ every-day
erences failed to address the issue of spatial correlation among their
actions.
pellet group count observations in their analysis. Failing to account
Studying habitat selection by herbivores, such as reindeer, demands
for zero-inflation and correlation can induce substantial bias in the
a hierarchical or multiscale approach to minimize the risk of missing
estimates of effects (Kassahun et al., 2014) and invalidate any statis-
important behavioral responses to factors that have a different impact
tical inference, due to the violation of the mean−variance relationship
at different scales (Northrup, Anderson, Hooten, & Wittemyer, 2016;
imposed by ordinary generalized linear models, for example, binomial
Senft et al., 1987; Skarin & Åhman, 2014). Noninteractive factors, for
and Poisson’s models (Kassahun et al., 2014; Lee et al., 2016). Using
example, barriers, have an impact on habitat selection at the large geo-
a suitable hierarchical generalized linear model (Lee & Nelder, 1996)
graphical scale and may limit selection at local scales (Northrup et al.,
with spatially correlated random effects, for example, a spatial Poisson
2016; Senft et al., 1987). Earlier studies of reindeer and caribou show
(Lee et al., 2016) or a binomial model, we may be able to overcome
clear patterns in avoiding infrastructure and human activity over rela-
this problem.
tively large distances, sometimes several kilometers (e.g., Beyer et al.,
The aim of this study was to evaluate whether reindeer habitat
2016; Johnson, Ehlers, & Seip, 2015; Skarin & Åhman, 2014; Vistnes
use, measured by fecal pellet group abundance, in the vicinity of the
& Nellemann, 2008). Vistnes and Nellemann (2008) found that studies
wind farms was lower during the construction and operation phase of
examining the effect of disturbance on reindeer and caribou within
two relatively small wind farms (8 and 10 wind turbines, respectively)
2 km of the source and/or during short time periods often did not re-
compared to the period before construction. Because the reindeer are
veal any effect of disturbance. The majority of the studies in which the
likely to be annoyed by the sound and sight of the wind turbines as
effects over distances greater than 2 km and/or during a longer time
well as the increased human activities (e.g., sound from vehicles asso-
period were considered, revealed negative effects of the disturbance
ciated with wind farm construction and maintenance), we hypothesize
|
3872
SKARIN and ALAM
that they would avoid or decrease their usage of the areas nearby the
Sweden (Figure 1). The study area was used by a part of the total herd:
wind farm during the construction and operation phases compared
approximately 1,200 female reindeer and their calves (the total number
to the preconstruction phase. This hypothesis was tested using a BA
of female reindeer in the whole herd ranged between 4,144, and 4,854
design (Strickland et al., 2011). Overall impact of the wind farm con-
over the study years). Every year in April, migration took place (“by
struction and operation phase on reindeer habitat use was evaluated
foot” in all years except 2015, when the reindeer were moved with
at both regional (reindeer range used from calving to autumn, within
trucks), with the reindeer herd moving from the winter ranges in the
15 km of the wind farm) and local (wind farm mountains within 2 km
east to the summer ranges in the west. After migration, the reindeer
from wind turbines) scales using pellet group counts in relation to dis-
were released into the study area (see arrows in Figure 1) at the begin-
tance to wind turbine in association with time period, after controlling
ning of May (2 May 2009, 10 May 2010 and 2011, and 1 May 2015;
for the possible confounding effects, and spatial correlation.
for the other years, we do not have an exact date of arrival). The reindeer used the area primarily during the calving season and then moved
2 | MATERIAL AND METHODS 2.1 | Study area
in and out of the area during the whole snow-free season until late autumn when they were moved back to the winter ranges. At the end of June, reindeer were gathered by the herders for calf marking and moved to the closest corral, thus redistributing the reindeer to some
The study was conducted in and around the two wind farms near
extent. In the early autumn (from the end of August), reindeer concen-
to each other, on Storliden mountain and Jokkmokksliden mountain
trated their activity toward the southern side of Storliden before they
(where eight and 10 wind turbines, respectively, were constructed
moved out of the area freely or because of the herders’ action.
in 2010–2011), located in the calving and postcalving ranges of the
The study area is characterized by a boreal forest landscape, in-
Malå forest reindeer herding community (65°14′, 18°58′) in northern
terspersed with mires, lakes and hills or smaller mountains, with the
F I G U R E 1 Map showing part of the calving area of the Malå reindeer herding community and the study area, with local scale pellet group count plots marked with red dots, the regional scale pellet group counts marked with brown dots, and the important reindeer migration routes in the herding community marked in yellow. Arrows show approximate sites where the reindeer were let out into the calving ranges after the migration “by foot” controlled by the herders ©Lantmäteriet i1204/764
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forested land comprising old growth forest, clear cuts, and plantations.
plots were positioned and marked with a wooden stick, and after the
The whole study area is a managed forest; when the trees are 70 years), 600 m north and
pellet groups being hidden by understory vegetation, that is, at the end
1200 m west of the wind farm were clear cut in May 2012 and in July
of the calving season each year. Thus, the inventory in 2010 mainly
2013, respectively.
represented the reindeer use prior to the construction of the wind farm and the first 15 days of the construction work at Jokkmokksliden
2.2 | Wind farm construction site and existing infrastructure
during calving and was treated as representative of reindeer use during the “preconstruction” phase. The inventory in 2011 solely represented the construction phase. The inventory in 2012 covered both
The year 2009 was defined as the predevelopment year (hereafter re-
part of the construction phase in 2011 and the operation phase in May
ferred to as the “pre-construction” phase), during which the area had
2012, and thus represented a mix of construction and operation phase
existing infrastructure such as a road network, power lines, and an un-
(Table 1) plus in addition the forest activity at Storliden in May 2012.
derground mine on the north side of Storliden (this ceased working in
However, to keep things simple and to have a large enough sample to
2008). Construction work started on 10 May 2010 at Jokkmokksliden,
assure stability of the inference on the effects of the different phases,
and on 1 June 2010 at Storliden. To access the wind farms, 22 km of
we treat the inventories from 2011 and 2012 as representative of the
roads was constructed, with 8.5 km of 36 kV power lines connecting
construction period. Because of the overlap of data collection in 2012
to the existing power grid via the new utility station built in between
between operation and construction phase, conclusions drawn on the
the wind farms. The full infrastructure at Jokkmokksliden, was devel-
effect of construction period should be regarded as a mixed effect
oped during 2010 and the first five wind turbines were constructed,
of construction and operation (with most weight being given to the
with five more turbines being erected in 2011. At Storliden, the road
construction period). The inventories from 2013, 2014, and 2015 rep-
network and power lines were established in 2010 and the turbines
resented the operation phase, except for the forestry activity in July
were put in place in 2011. All turbines started to generate electricity
2013. It is generally believed that there is some random variation in
in November 2011. The years 2010 and 2011 are hereafter referred
habitat use by reindeer between years (Nicholson et al., 2016), which
to as the “construction” phase, as development continued throughout.
was also seen in the initial analysis of the data (Figure 2); therefore, it
The years after construction (2012–2015) are here referred to as the
makes sense to average the usage over a number of years to get stable
“operation” phase, as the wind turbines were running.
estimate of the effects of the wind farm. The study followed a point transect survey design (Buckland et al., 2001) at the local scale within 2 km of the wind farms, covering 15 km2
2.3 | Pellet group counts
around each wind farm, and at the regional scale within 15 km of the
The fecal pellet group count, used as a proxy to measure habitat use
wind farm, covering 250 km2, the core of the reindeer calving range
by the reindeer, was conducted every year (2010–2015), over a pe-
(Figure 1). In 2009, 1,315 plots were inventoried, and in the follow-
riod of 4–9 days between 24 May and 8 June (Table 1). The pellet
ing years, 1,162–1,248 plots were inventoried. Each plot was 15 m2
groups were counted using the fecal accumulation rate in 2010–2015
(radius = 2.18 m). At the local scale, the distance between transects
(Campbell, Swanson, & Sales, 2004; Skarin, 2007). Thus, in 2009, the
was 300 m and the distance between each plot on the transects was
T A B L E 1 Date of pellet group counts in the Malå reindeer herding community, including phases for Storliden and Jokkmokksliden wind farm development and how this corresponded to reindeer use of the area (note that reindeer did not use the area during the winter seasons from November to April) Phase of wind farm development Inventory not used in statistical analysis
Date for pellet group count 1–9/6 2009
Date of reindeer use represented by each count May in 2009 and 2008 and prior to this depending on pellet group decay rate within each vegetation type
Preconstruction and 15 days construction
28/5–1/6 2010
10/6 2009–27/5 2010
Construction
23/5–26/5 2011
2/6 2010–22/5 2011
Construction and 30 days operation
28/5–1/6 2012
27/5 2011–27/5 2012
Operation
27/5–2/6 2013
2/6 2012–26/5 2013
Operation
2/6–8/6 2014
3/6 2013–1/6 2014
Operation
25/5–29/5 2015
9/6 2014–24/5 2015
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2012
2013
2014
2015
2011
2012
2013
Year
Storliden
Jokkmokksliden
2015
2014
2015
1.0
2014
2010
2011
2012
2013
2014
2015
Year
0.8 0.5
0.6
0.7
Rel. Freq.
0.9
0.9 0.8 0.7 0.5
2010
Year
0.6
Rel. Freq.
0.8
0.9 2011
0.5
2010
1.0
0.5
0.6
0.7
0
0.7
1
Rel. Freq.
0.8
Pellet−group Count >2
0.6
Rel. Freq.
0.9
1.0
Region
1.0
Combined
2010
2011
2012
2013
Year
F I G U R E 2 Bar graphs of the relative frequency of pellet group counts within each study year for all data combined, data from the count at the region scale, and data from the count at the local scale from Storliden and from Jokkmokksliden (2010 – Preconstruction, 2011 and 2012— Construction, and 2012–2014—Operation)
100 m. At the regional scale, the plots were placed along the sides of
variables included were vegetation type, elevation, slope, minimum
29 1 × 1 km squares, with 20 plots every 200 m along the perimeter
distance to large (>5 m) and small (5 m stem length) Clear cuts (
