ArticlePDF Available

The effect of target extent on the location of optimal protected areas networks in Canada

DOI:10.1007/s10980-007-9126-2
Authors:
Yolanda Wiersma at Memorial University of Newfoundland
Yolanda Wiersma
Download full-text PDF
Read full-text
Download citation

Abstract

Various jurisdictions in Canada are currently undertaking, or have recently completed, planning exercises as part of implementation and expansion of representative reserve networks (networks of provincial parks, national parks, ecological reserves, etc.). These exercises have resulted in recommendations to governments about which areas of land should be set aside as protected areas, and different levels of government have been involved in the process of land acquisition. In some cases, planning exercises have included implementation of new protected areas to complement existing reserve networks. Many of these exercises have applied principles such as complementarity, using heuristic algorithms that are well-described in the literature. These planning exercises may be conducted within politically or ecologically bounded target regions of varying extents. Here, I develop candidate locations for representative reserve areas for disturbance-sensitive mammals across Canada. I use ecologically bounded regions (within the national boundaries of Canada) at three different levels of spatial hierarchy: mammal provinces, ecozones, and ecoregions. I show that the extent of the target region has an effect on the minimum number of protected areas required to achieve representation; a larger region requires fewer protected areas than the sum of the protected areas required to represent its component regions at a lower level of spatial hierarchy. The results illustrate that selection of sites for inclusion in a reserve network is highly scale-dependent, and different spatial extents in the target regions may introduce inefficiencies or redundancies in selecting representative protected areas.
Content uploaded by Yolanda Wiersma
Author content
All content in this area was uploaded by Yolanda Wiersma on May 05, 2015
Content may be subject to copyright.
This version is a postprint. It has the same peer-reviewed content as the published version, but lacks
publisher layout and branding. It is available under License Creative Commons Attribution Non-
commercial. Published version is copyrighted and available at Cote D, D Kehler, C Bourne, YF Wiersma.
2009. A connectivity index for riverscapes. Landscape Ecology 24: 101-113. doi: 10.1007/s10980-008-
9283-y
The Effect of Scale on the Design of Optimal Protected Areas Networks in Canada
4
Yolanda F. WIERSMA
8
Department of Integrative Biology
University of Guelph
50 Stone Road East
Guelph, Ontario, N1G 2W1, Canada
12
ywiersma@uoguelph.ca
Ph. 519.824.4120 x56307
Fax. 519.767.1656
16
20
24
28
Date of Manuscript Draft: April 12, 2006
32
Word count: 4,706
36
Scale and protected areas networks, Wiersma, Y.F., page 2
Original paper published in Landscape Ecology (DOI: 10.1007/s10980-007-9126-2)
This version is a postprint. It has the same peer-reviewed content as the published version, but lacks
publisher layout and branding. It is available under License Creative Commons Attribution Non-
commercial. Published version is copyrighted and available at Wiersma YF. 2007. The effect of target
extent on the location of optimal protected areas networks in Canada Landscape Ecology 22: 1477-1487.
doi: 10.1007/s10980-007-9126-2
2
Abstract
Various jurisdictions in Canada are currently undertaking, or have recently completed, planning
for representative reserve networks, several applying principles such as complementarity, using
heuristic algorithms that are generally available. These exercises may be conducted within
4
politically- or ecologically-bounded target regions of varying extents. Here, I develop
representative reserve networks for disturbance-sensitive mammals across Canada. I use three
different ways of defining ecologically-bounded regions at different levels of spatial hierarchy
(mammal provinces, ecozones, and ecoregions) as the target zones to identify near-optimal
8
solutions for protected areas across multiple spatial scales. I show that the extent of the target
region has an effect on the minimum number of protected areas required to achieve representation;
a larger region requires fewer protected areas than the sum of the protected areas required to
represent its component regions at a smaller level of spatial hierarchy. The results illustrate that
12
reserve network planning is highly scale-dependent, and different spatial extents in the target
regions may introduce inefficiencies or redundancies in identifying representative reserve
networks.
16
Keywords: ecoregions, ecozones, protected areas, representative networks, redundancy,
reserve design, spatial scale
Scale and protected areas networks, Wiersma, Y.F., page 3
Original paper published in Landscape Ecology (DOI: 10.1007/s10980-007-9126-2)
This version is a postprint. It has the same peer-reviewed content as the published version, but lacks
publisher layout and branding. It is available under License Creative Commons Attribution Non-
commercial. Published version is copyrighted and available at Wiersma YF. 2007. The effect of target
extent on the location of optimal protected areas networks in Canada Landscape Ecology 22: 1477-1487.
doi: 10.1007/s10980-007-9126-2
3
Introduction
Designs for representative protected areas networks within target regions consist of goals for
including (representing) a given number of species or land cover types from the target region
within the protected areas system. Researchers have focused mainly on methods to select
4
representative areas (e.g., Margules et al. 1988; Pressey et al. 1993), as well as on methods to
ensure species persistence within representative networks (Cowling et al. 2003; Kerley et al. 2003;
Pressey et al. 2004). Relatively little attention has been paid to the effect of varying the target
region on the number of protected areas required within it to achieve a given level of
8
representation, what research has been done has focused on varying the extent within geopolitical
target areas, and not ecologically-defined ones (e.g., Pressey and Nichols 1989; Erasmus et al.
1999; Rodrigues and Gaston 2002).
Conservation issues are often cited as being “scale-dependent” (Wiens 1989). Landscape
12
ecologists consider spatial scale to have two components: grain, defined as “the finest level of
spatial resolution possible within a given data set” (Turner et al. 2001: 29); and extent, defined as
the “size of the study area... under consideration” (Turner et al. 2001: 29). A few studies have
explicitly examined how spatial scaling affects delineation of representative protected areas
16
networks. These have either focused on the effect of varying the grain size (spatial resolution of
data and/or size of planning units) in the analysis (e.g., Kunin 1997; Rouget 2003; Wiersma and
Nudds 2003), or on varying the extent of the target region (e.g., Pressey and Nichols 1989;
Erasmus et al. 1999; Rodrigues and Gaston 2002), but not both.
20
. Varying the size of the planning units on the selection of representative protected areas in
Canada (Wiersma and Nudds in press) had little effect on the number of protected areas required
to represent mammal species within the mammal provinces (i.e., the target regions; Hagmeier
Scale and protected areas networks, Wiersma, Y.F., page 4
Original paper published in Landscape Ecology (DOI: 10.1007/s10980-007-9126-2)
This version is a postprint. It has the same peer-reviewed content as the published version, but lacks
publisher layout and branding. It is available under License Creative Commons Attribution Non-
commercial. Published version is copyrighted and available at Wiersma YF. 2007. The effect of target
extent on the location of optimal protected areas networks in Canada Landscape Ecology 22: 1477-1487.
doi: 10.1007/s10980-007-9126-2
4
1966) of Canada, when the planning unit size varied between 2700-13,000 km2. Similarly, Kunin
(1997) found that spatial patterns were scale-invariant at grain sizes ranging from 2-50 km2 when
modelling protected areas using European and British floral atlas data. However, Rouget (2003)
showed that the number of protected areas varied when broad scale (3900 ha planning units) and
4
fine scale (252 ha planning units) data were used for conservation planning in the Agulhas Plain in
South Africa, although representation efficiency was similar.
Pressey and Nicholls (1989) subdivided a geopolitical unit (Western Division of New
South Wales) into ecologically-defined regions, subregions, and provinces (based on geology,
8
vegetation and rainfall). They conducted reserve selection algorithms at different levels of spatial
hierarchy, and found that more than twice as many sites were needed in the geopolitical unit when
it was subdivided in the regions and subregions, than when the Western Division as a whole was
considered as a target region (Pressey and Nicholls 1989). In a similar study, Erasmus et al. (1999)
12
looked at minimum representation requirements for mammals within 4 provinces in South Africa,
and across all 4 provinces combined. They found that 3 times as many sites were needed in the
within-province analysis than in the across-province analysis (Erasmus et al. 1999). Erasmus et al.
(1999) also showed that the sites identified across provinces did not coincide with those selected
16
within-provinces. Rodrigues and Gaston (2002) examined the effect of varying the extent of the
geopolitical target region and found that subdividing a geopolitical region (i.e., a country) into
smaller geopolitical units (i.e., provinces) increased the number of sites required to represent bird
species by over 10 times. They demonstrated that using geopolitical units as target regions in
20
which to implement representative protected areas resulted in the creation of “apparently rare”
species; species whose ranges were just within a political unit, or which were vagrants or
introductions, but which had widespread distribution elsewhere. These apparent rarities had a
Scale and protected areas networks, Wiersma, Y.F., page 5
Original paper published in Landscape Ecology (DOI: 10.1007/s10980-007-9126-2)
This version is a postprint. It has the same peer-reviewed content as the published version, but lacks
publisher layout and branding. It is available under License Creative Commons Attribution Non-
commercial. Published version is copyrighted and available at Wiersma YF. 2007. The effect of target
extent on the location of optimal protected areas networks in Canada Landscape Ecology 22: 1477-1487.
doi: 10.1007/s10980-007-9126-2
5
disproportionate influence on the selection of representative sites to be set aside as representative
conservation areas (Rodrigues and Gaston 2002).
In contrast to these studies which have examined the effects of grain or extent, other
landscape-level ecological analyses have addressed both. In an analysis involving land-use
4
planning in the Philippines, Verburg and Veldkamp (2004) showed that varying grain and extent
yielded different results in their land use change models. They felt that these differences illustrated
that there is no optimal spatial scale for assessing land use change, but that each scale has inherent
values and shortcomings, and that the scale should be chosen to be appropriate to the research
8
question (Verburg and Veldkamp 2004). Similarly, Palmer and White (2004) showed that
variations in grain and extent had implications for how the species-area relationship was
manifested in a North Carolina forest. The results from both of the studies have implications for
protected areas network design; however this was not an explicit component in either of these two
12
analyses where both grain and extent were analyzed.
That a fuller examination and appreciation of the effects of the spatial extent of
ecologically-bounded regions on protected areas network design has not yet materialized may be
due to the simple and practical reason that planning for protected areas often is carried out in well-
16
defined areas by individual jurisdictions (i.e., provinces, states, territories) independently of any
analysis of where protected areas exist outside of the planning agency’s political boundaries (e.g.,
YPAS 1998; Purchase 2003). However, because patterns of species distribution do not follow
political boundaries, consideration of protected areas requirements outside political boundaries
20
may be more appropriate.
To be efficient, protected areas should be located so as to maximize species representation
with a minimum amount of area. Delineation of representative protected areas networks is most
Scale and protected areas networks, Wiersma, Y.F., page 6
Original paper published in Landscape Ecology (DOI: 10.1007/s10980-007-9126-2)
This version is a postprint. It has the same peer-reviewed content as the published version, but lacks
publisher layout and branding. It is available under License Creative Commons Attribution Non-
commercial. Published version is copyrighted and available at Wiersma YF. 2007. The effect of target
extent on the location of optimal protected areas networks in Canada Landscape Ecology 22: 1477-1487.
doi: 10.1007/s10980-007-9126-2
6
ecologically meaningful if carried out within ecologically-defined target regions, such as in the
mammal provinces of Canada (Fig 1; Hagmeier 1966) or within ecozones (e.g., Wiken et al. 1996)
or ecoregions (Ecological Stratification Working Group 1995) rather than within politically-
bounded target areas. These ecologically-defined regions can vary in extent and in the
4
characteristics upon which they were delineated, and thus, determining which is most appropriate
as a target extent for delineating representative protected areas can be difficult. Research has
shown that the areas along the boundaries of the mammal provinces of Canada have a high degree
of similarity in species composition with adjacent provinces (Glenn 1990). Such spatial patterns in
8
species turnover may result in the phenomena where representative protected area networks that
are defined at smaller spatial extents may actually introduce redundancies compared to the case
where a network is planned at a larger spatial extent. However, mammal provinces may not be the
most appropriate target region for delineating protected areas, as other taxa and features that occur
12
at different spatial scales than mammals have to be taken into consideration. In Canada, the
stratified system of ecozones and ecoregions (Ecological Stratification Working Group 1995) is
seen as a potentially useful framework for target regions, as these have been delineated on the
basis of landforms, soils, climate, and vegetation combined. While ecologically-defined target
16
regions such as mammal provinces, ecozones or ecoregions, are intuitively more appropriate than
politically-defined ones such as provinces, states or territories, it is important to remember that
ecologically-defined regions are still defined by humans, and thus from nature’s point of view,
may be arbitrary (see McDonald et al. 2005 for a discussion on the potentially arbitrary nature of
20
ecoregion boundaries).
Here, I examine whether and how spatial extent of the target region affects the number and
location of protected areas in a representative protected areas network comprised of protected
Scale and protected areas networks, Wiersma, Y.F., page 7
Original paper published in Landscape Ecology (DOI: 10.1007/s10980-007-9126-2)
This version is a postprint. It has the same peer-reviewed content as the published version, but lacks
publisher layout and branding. It is available under License Creative Commons Attribution Non-
commercial. Published version is copyrighted and available at Wiersma YF. 2007. The effect of target
extent on the location of optimal protected areas networks in Canada Landscape Ecology 22: 1477-1487.
doi: 10.1007/s10980-007-9126-2
7
areas (that are predicted to be large enough to contain their historical complement of species even
in the face of habitat insularization) in Canada. An analysis of the effect of varying the grain size
has already been conducted on this data set (Wiersma and Nudds in press). Thus this is the first
system of which I am aware which has tested the effects on representative networks of varying
4
both the grain and the extent within ecologically defined target areas. I compare the number and
location of representative protected areas between three types of ecologically defined regions;
mammal provinces, ecozones, and ecoregions. I hypothesize that there will be some similarity in
the optimal locations for protected areas between the three target regions, because underlying
8
hotspots of richness or rarity will be relatively consistent between scales. However, I predict that
the number of protected areas needed to represent larger target regions will be less than the sum of
the parts of smaller target regions that are nested within the larger ones.
12
Methods
The effect of spatial extent was examined using 3 different target regions for identifying
representative protected areas networks. The largest target region examined representation
requirements within 8 of the mammal provinces of Canada (Fig. 1; Hagmeier 1966). Mammal
16
provinces were selected because they have been the focus of recent research in Canada on
identifying protected areas design requirements (e.g., Glenn and Nudds 1989; Gurd and Nudds
1999; Gurd et al. 2001). However, many planning agencies in Canada prefer to examine
representation issues within the ecological stratification system of ecozones, ecoregions, and
20
ecodistricts (Ecological Stratification Working Group 1995). These classifications are based
largely on similarities in vegetation, soils, climate, and topography. Here, I used 12 of the
ecozones of Canada that approximately overlapped with the mammal provinces analyzed as a
Scale and protected areas networks, Wiersma, Y.F., page 8
Original paper published in Landscape Ecology (DOI: 10.1007/s10980-007-9126-2)
This version is a postprint. It has the same peer-reviewed content as the published version, but lacks
publisher layout and branding. It is available under License Creative Commons Attribution Non-
commercial. Published version is copyrighted and available at Wiersma YF. 2007. The effect of target
extent on the location of optimal protected areas networks in Canada Landscape Ecology 22: 1477-1487.
doi: 10.1007/s10980-007-9126-2
8
second set of target regions (Fig. 2). Finally, I examined representation requirements using
ecoregions as the target region. However, I constrained the analysis to the 18 ecoregions that lie
within the Yukon Territory (see inset map in Fig. 1). In addition to comparing the number and
location of protected areas between these different target regions, each set of target regions were
4
combined to test whether the number of protected areas required when a region was considered as
a whole was less than the sum of the parts, as has been found with studies that conducted similar
analyses within and across geopolitical units (Erasmus et al. 1999; Rodrigues and Gaston 2002).
# FIGURE 1 APPROXIMATELY HERE
8
# FIGURE 2 APPROXIMATELY HERE
At the mammal province and ecozone extents, the target regions were sampled for richness
and composition of disturbance sensitive mammals (defined by Glenn and Nudds (1989) sensu
Humphreys and Kitchener (1982)) in candidate sites for protected areas. This was obtained by an
12
overlay analysis of mammal range data (Patterson et al. 2003) in a Geographic Information System
(GIS; ArcInfo v. 8, Environmental Systems Research Institute, Redlands, CA) using sample plots
that represented the lowest (2700 km2) estimate for minimum reserve area (MRA) below which
species are estimated to have be lost due to insularization (Gurd et al. 2001).
16
A minimum representative network at the national and mammal province extents was
identified from the suite of candidate sites using a rarity-based heuristic algorithm (Margules et al.
1988; Pressey et al. 1993). Previous analysis (Wiersma and Nudds 2004) has shown rarity-based
algorithms to be a more efficient solution for finding representative solution sets than richness-
20
based ones. Reserves were selected and added to the system based on presence of rare species in
candidate plots, until all species were represented at least once in a reserve (determined as full or
partial overlap between a species’ range and a sample MRA plot). Species richness of plots was
Scale and protected areas networks, Wiersma, Y.F., page 9
Original paper published in Landscape Ecology (DOI: 10.1007/s10980-007-9126-2)
This version is a postprint. It has the same peer-reviewed content as the published version, but lacks
publisher layout and branding. It is available under License Creative Commons Attribution Non-
commercial. Published version is copyrighted and available at Wiersma YF. 2007. The effect of target
extent on the location of optimal protected areas networks in Canada Landscape Ecology 22: 1477-1487.
doi: 10.1007/s10980-007-9126-2
9
used as the criteria for breaking ties. The minimum sets for all of the ecozones or mammal
provinces combined (i.e., nearly all of the country; hereafter referred to as the “national extent”)
were compared to minimum sets for each of the component mammal provinces or ecozones to test
whether the sum of the protected areas needed to represent the current distribution of mammals in
4
the component target regions was greater than the number needed to represent the country as a
whole.
At the extent of the Yukon ecoregions, the shape and smaller size of the ecoregions did not
allow for the use of the same suite of candidate plots as at the extents of the mammal provinces
8
and of the nation as a whole. Instead, locations of rare species were identified and 2700 km2
minimum reserve areas were delineated around them. The composition of these plots was then
compared to the mammal richness of the ecoregions, and an additional site was selected if needed
(see Wiersma and Urban 2005 for details), following the same algorithm rules as in the ecozones
12
and mammal provinces. The minimum requirement for representative protected areas for the
ecoregions of the Yukon were compared to those for the Yukon territory as a whole to test whether
the sum of the protected areas needed to represent the current distribution of mammals in the
component ecoregions was greater than the number needed to represent the territory when
16
considered as a target region on its own.
Results
All of the mammals of Canada, taken as a whole (excluding the high arctic), could be included in a
20
few as 11 or 12 sites (Table 1). The sum of the mammal provinces considered individually was 28,
with individual mammal provinces needing between 2-6 sites (Table 1; Fig. 3). The sum of the
ecozones considered individually was 59, with individual ecozones needing between 2-7 sites
Scale and protected areas networks, Wiersma, Y.F., page 10
Original paper published in Landscape Ecology (DOI: 10.1007/s10980-007-9126-2)
This version is a postprint. It has the same peer-reviewed content as the published version, but lacks
publisher layout and branding. It is available under License Creative Commons Attribution Non-
commercial. Published version is copyrighted and available at Wiersma YF. 2007. The effect of target
extent on the location of optimal protected areas networks in Canada Landscape Ecology 22: 1477-1487.
doi: 10.1007/s10980-007-9126-2
10
(Table 1; Fig. 3). The Yukon Territory on its own required 3 sites, while the sum of the individual
ecoregions of the territory was 29, with individual ecoregions only needing 1-2 sites (Table 1; Fig.
3). Thus, at each spatial extent, there is an “economy of scale”, with fewer protected areas needed
as the extent of the target region increases. The effect of varying the spatial extent seems to vary
4
with the differences in extent; between the Yukon ecoregions, and the territory as a whole, almost
10 times as many sites were needed in the component parts, between the ecozones individual and
as a whole over 5 times as many sites were needed, whereas between the mammal provinces
individually and as a whole, only slightly more than twice as many sites were needed.
8
# TABLE 1 APPROXIMATELY HERE
# FIGURE 3 APPROXIMATELY HERE
In most cases, the plots selected at the national extent were also important at the extent of
the individual mammal provinces (Fig. 4). The plots that were important within the Yukonian
12
mammal province coincided with areas that were important within individual ecoregions of the
Yukon Territory (Fig. 5). Of the representative sites at the national extents, 75% of the sites from
the across-mammal provinces analysis were also found in the representative sets in the individual
mammal provinces, while 45% of the sites from the across-ecozone analysis were found in the
16
representative sets in the individual ecozones (Fig. 6).
# FIGURE 4 APPROXIMATELY HERE
# FIGURE 5 APPROXIMATELY HERE
#FIGURE 6 APPROXIMATELY HERE
20
Scale and protected areas networks, Wiersma, Y.F., page 11
Original paper published in Landscape Ecology (DOI: 10.1007/s10980-007-9126-2)
This version is a postprint. It has the same peer-reviewed content as the published version, but lacks
publisher layout and branding. It is available under License Creative Commons Attribution Non-
commercial. Published version is copyrighted and available at Wiersma YF. 2007. The effect of target
extent on the location of optimal protected areas networks in Canada Landscape Ecology 22: 1477-1487.
doi: 10.1007/s10980-007-9126-2
11
Discussion
A comparison of sites selected at the extents of individual ecoregions within an ecozone, or with
ecozones or mammal provinces within the country as a whole, is useful for identifying high
priority areas for conservation. Those sites that are important at more than one extent should be
4
priority areas for conservation over sites that are important at only one extent. A representative
protected areas network at a national extent is much more efficient than networks in individual
mammal provinces, as the total number of sites is 2-43% of the sum of the parts for ecozones and
mammal provinces, respectively. The mammal provinces, in turn, appear to be more efficient than
8
component ecoregions, at least for the Yukon (the Yukon Territory roughly coincides with the
Yukonian mammal province). A similar result of gains in efficiency as larger target regions are
considered has been demonstrated with subdivisions and agglomerations of geopolitical target
units, with the total number of sites at the larger extent being anywhere from 2-10 times as many
12
as the sum of the parts (Pressey and Nichols 1989; Erasmus et al. 1999; Rodrigues and Gaston
2002). The comparison between the location of representative protected areas at spatial extents
that are nested within each other (ecoregions within a territory, or mammal provinces/ecozones
within the country) identifies those sites that are redundant with plots elsewhere when
16
representation is constrained within smaller target regions. However, redundancies in species
representation may be desirable as they may capture more genetic diversity of species, supply
populations for a rescue effect in case of local extinctions, represent subspecies or unique types, or
capture diversity of other taxa or physiographic features in addition to mammals (Stoms et al.
20
2004). The possibilities for redundancies may also assist in the case when a single political
jurisdiction can not allocate enough land to a protected area to achieve an adequate minimum size.
Scale and protected areas networks, Wiersma, Y.F., page 12
Original paper published in Landscape Ecology (DOI: 10.1007/s10980-007-9126-2)
This version is a postprint. It has the same peer-reviewed content as the published version, but lacks
publisher layout and branding. It is available under License Creative Commons Attribution Non-
commercial. Published version is copyrighted and available at Wiersma YF. 2007. The effect of target
extent on the location of optimal protected areas networks in Canada Landscape Ecology 22: 1477-1487.
doi: 10.1007/s10980-007-9126-2
12
In such a situation it is valuable to investigate whether the solution might be in optimally located
transboundary protected areas.
The comparison of minimum requirements when the extent of the target region varies is
useful in that it identifies high priority areas and possible redundancies. However, this analysis
4
was constrained to mammals, the distributions of many of which cross more than one mammal
province or ecozone/ecoregion. There are good reasons for developing representative protected
areas networks within smaller target regions than mammal provinces, even if mammals remain the
target organism. Representative networks for mammals within one ecozone may capture a
8
different assemblage of species and vegetation types than a representative network in another
ecozone. Warman et al. (2004) showed that a representative network for mammals could capture
between 33-96% of other taxa (reptiles, amphibians, birds). Thus, redundancies between ecozones
might capture more of these other taxa (which may not be as widely distributed across the country)
12
than if a representative network for mammals is delineated only at the national, or mammal
province, extent.
For practical reasons related to legislation and management, planning for protected areas
will likely continue to be carried out within politically bounded areas. Nonetheless, it would be
16
helpful for protected areas planners to consider analyses such as this one, at least with
neighbouring jurisdictions. Although collaboration across boundaries might carry slightly higher
costs, in the end it may yield efficiencies if the two governments can share protection of areas
along their borders and/or identify areas that are redundant between the two jurisdictions.
20
Acknowledgements
Scale and protected areas networks, Wiersma, Y.F., page 13
Original paper published in Landscape Ecology (DOI: 10.1007/s10980-007-9126-2)
This version is a postprint. It has the same peer-reviewed content as the published version, but lacks
publisher layout and branding. It is available under License Creative Commons Attribution Non-
commercial. Published version is copyrighted and available at Wiersma YF. 2007. The effect of target
extent on the location of optimal protected areas networks in Canada Landscape Ecology 22: 1477-1487.
doi: 10.1007/s10980-007-9126-2
13
YFW was supported by an Ontario Graduate Scholarship and a grant from the Canadian Council
on Ecological Areas. Mammal data was provided by NatureServe in collaboration with Bruce
Patterson, Wes Sechrest, Marcelo Tognelli, Gerardo Ceballos, The Nature Conservancy –
Migratory Bird Program, Conservation International – CABS, World Wildlife Fund – US, and
4
Environment Canada – WILDSPACE. Thanks to D. Sleep, T.D. Nudds and R.L. Pressey for
helpful comments on an earlier draft of the manuscript, and to K. Lindsay for originally proposing
the research idea. Additional research support was provided by grants from NSERC and Parks
Canada to TDN.
8
Scale and protected areas networks, Wiersma, Y.F., page 14
Original paper published in Landscape Ecology (DOI: 10.1007/s10980-007-9126-2)
This version is a postprint. It has the same peer-reviewed content as the published version, but lacks
publisher layout and branding. It is available under License Creative Commons Attribution Non-
commercial. Published version is copyrighted and available at Wiersma YF. 2007. The effect of target
extent on the location of optimal protected areas networks in Canada Landscape Ecology 22: 1477-1487.
doi: 10.1007/s10980-007-9126-2
14
Table 1. Three kinds of target regions with the number of sites required to represent them, as
identified using a rarity-based heuristic algorithm.
Target region
Area (km2)
# Sites to represent
Mammal Provinces
Alleghenian/Illinoian
420,192
3
Alleghenian (western portion)
121,378
2
Eastern Canadian
978,468
3
Western Canadian
2,089,818
6
Saskatchewanean
499,111
2
Montanian
558,468
5
Vancouverian
457,819
4
Yukonian
725,852
3
All provinces combined
420,192
12
Ecozones
Atlantic Maritime
282,245
4
Mixedwood Plains
168,913
3
Boreal Shield
2,072,417
7
Boreal Plains
737,397
6
Boral Cordillera
468,093
5
Montane Cordillera
488,013
6
Pacific Maritime
250,094
6
Prairies
465,303
7
Scale and protected areas networks, Wiersma, Y.F., page 15
Original paper published in Landscape Ecology (DOI: 10.1007/s10980-007-9126-2)
This version is a postprint. It has the same peer-reviewed content as the published version, but lacks
publisher layout and branding. It is available under License Creative Commons Attribution Non-
commercial. Published version is copyrighted and available at Wiersma YF. 2007. The effect of target
extent on the location of optimal protected areas networks in Canada Landscape Ecology 22: 1477-1487.
doi: 10.1007/s10980-007-9126-2
15
Taiga Shield
1,445,900
5
Taiga Plains
653,888
5
Taiga Cordillera
265,233
2
Hudson Plains
446,528
3
All ecozones combined
7,744,024
11
Yukon Ecoregions
British Richardson Mountains
22,989
2
Eagle Plains
20,394
1
Hyland Highlands
14,660
2
Klondike Plateau
38,206
2
Liard Basin
21,121
2
Mackenzie Mountains
190,238
1
North Olgilvie Mountains
39,203
1
Old Crow Basin
14,589
2
Old Crow Flats
5,964
1
Peel River Plateau
14,812
1
Pelly Mountains
34,194
2
Ruby Ranges
22,720
1
Selwyn Mountains
35,541
2
St. Elias Mountains
17,603
1
Yukon Coastal Plain
4,402
1
Yukon Plateau (central)
26,803
2
Scale and protected areas networks, Wiersma, Y.F., page 16
Original paper published in Landscape Ecology (DOI: 10.1007/s10980-007-9126-2)
This version is a postprint. It has the same peer-reviewed content as the published version, but lacks
publisher layout and branding. It is available under License Creative Commons Attribution Non-
commercial. Published version is copyrighted and available at Wiersma YF. 2007. The effect of target
extent on the location of optimal protected areas networks in Canada Landscape Ecology 22: 1477-1487.
doi: 10.1007/s10980-007-9126-2
16
Yukon Plateau (north)
57,037
2
Yukon Southern Lakes
29,899
2
Yukon Stikine Highlands
6,972
1
All of Yukon ecoregions
476,560
3
Scale and protected areas networks, Wiersma, Y.F., page 17
Original paper published in Landscape Ecology (DOI: 10.1007/s10980-007-9126-2)
This version is a postprint. It has the same peer-reviewed content as the published version, but lacks
publisher layout and branding. It is available under License Creative Commons Attribution Non-
commercial. Published version is copyrighted and available at Wiersma YF. 2007. The effect of target
extent on the location of optimal protected areas networks in Canada Landscape Ecology 22: 1477-1487.
doi: 10.1007/s10980-007-9126-2
17
Figure Captions
Figure 1. Target regions in the analysis. Main map: the mammal provinces of Canada (Hagmeier
1966). For this study, the Eastern and Western Hudsonian, the Ungavan, and the Eastern Eskimoan
4
mammal provinces were excluded. The western portion of the Alleghenian mammal province was
analyzed separately, and the eastern portion of the Alleghenian mammal province was combined
with the Illinoian, yielding a total of eight replicate mammal provinces. Inset map: The Yukon
Territory and component ecoregions.
8
Figure 2. The ecozones of Canada included in this analysis.
Figure 3. Number of plots needed to represent all mammals in different target regions of different
12
extents. The national extent can be subdivided into either mammal provinces or ecozones. The
data for ecoregions is for those that fall within the Yukon Territory.
Figure 4. Map of Canada showing output of sites that meet minimum reserve area requirements of
16
2700 km2 and which have been selected as representative for mammals based on output from a
rarity-based heuristic reserve selection algorithms conducted using mammal provinces as target
regions. Plots that are circled in the Eastern mammal province indicate a series of plots that are
equivalent to each other in terms of meeting representation goals. Plots with dark shading are those
20
that are part of a minimum representative set for each individual mammal province. Plots with
thick outlines are those that are part of a minimum representative set for the country as a whole.
Thus, those with thick outlines and dark shading are selected at the two different scales (national
Scale and protected areas networks, Wiersma, Y.F., page 18
Original paper published in Landscape Ecology (DOI: 10.1007/s10980-007-9126-2)
This version is a postprint. It has the same peer-reviewed content as the published version, but lacks
publisher layout and branding. It is available under License Creative Commons Attribution Non-
commercial. Published version is copyrighted and available at Wiersma YF. 2007. The effect of target
extent on the location of optimal protected areas networks in Canada Landscape Ecology 22: 1477-1487.
doi: 10.1007/s10980-007-9126-2
18
and within individual mammal provinces), while those with thick outlines and no shading were
only selected at the national extent.
Figure 5. The minimum representative network for the ecoregions of the Yukon (results using the
4
richness based and rarity based algorithms were identical). Plots that are marked with a star
indicate those that were needed to represent the Yukonian mammal province.
Figure 6. Map of Canada showing output of sites that meet minimum reserve area requirements of
8
2700 km2 and which have been selected as representative for mammals based on output from a
rarity-based heuristic reserve selection algorithm conducted using ecozones as target regions. Plots
that are circled are those that are part of a minimum representative set for the country as a whole.
Thus, those that are stippled are important at the national scale, but not within ecozones, while
12
those that are circled and shaded in, are important at both spatial extents.
16
Scale and protected areas networks, Wiersma, Y.F., page 19
Original paper published in Landscape Ecology (DOI: 10.1007/s10980-007-9126-2)
This version is a postprint. It has the same peer-reviewed content as the published version, but lacks
publisher layout and branding. It is available under License Creative Commons Attribution Non-
commercial. Published version is copyrighted and available at Wiersma YF. 2007. The effect of target
extent on the location of optimal protected areas networks in Canada Landscape Ecology 22: 1477-1487.
doi: 10.1007/s10980-007-9126-2
19
Figure 1.
Scale and protected areas networks, Wiersma, Y.F., page 20
Original paper published in Landscape Ecology (DOI: 10.1007/s10980-007-9126-2)
This version is a postprint. It has the same peer-reviewed content as the published version, but lacks
publisher layout and branding. It is available under License Creative Commons Attribution Non-
commercial. Published version is copyrighted and available at Wiersma YF. 2007. The effect of target
extent on the location of optimal protected areas networks in Canada Landscape Ecology 22: 1477-1487.
doi: 10.1007/s10980-007-9126-2
20
4
Figure 2.
Scale and protected areas networks, Wiersma, Y.F., page 21
Original paper published in Landscape Ecology (DOI: 10.1007/s10980-007-9126-2)
This version is a postprint. It has the same peer-reviewed content as the published version, but lacks
publisher layout and branding. It is available under License Creative Commons Attribution Non-
commercial. Published version is copyrighted and available at Wiersma YF. 2007. The effect of target
extent on the location of optimal protected areas networks in Canada Landscape Ecology 22: 1477-1487.
doi: 10.1007/s10980-007-9126-2
21
0
10
20
30
40
50
60
70
national sum of
mammal
provinces
sum of
ecozones Yukon
territory sum of
ecoregions
number of sites required
Figure 3.
4
8
Scale and protected areas networks, Wiersma, Y.F., page 22
Original paper published in Landscape Ecology (DOI: 10.1007/s10980-007-9126-2)
This version is a postprint. It has the same peer-reviewed content as the published version, but lacks publisher layout and branding. It is available
under License Creative Commons Attribution Non-commercial. Published version is copyrighted and available at Wiersma YF. 2007. The effect of
target extent on the location of optimal protected areas networks in Canada Landscape Ecology 22: 1477-1487. doi: 10.1007/s10980-007-
9126-2
22
1
Figure 4.
2
Scale and protected areas networks, Wiersma, Y.F., page 23
Original paper published in Landscape Ecology (DOI: 10.1007/s10980-007-9126-2)
This version is a postprint. It has the same peer-reviewed content as the published version, but
lacks publisher layout and branding. It is available under License Creative Commons Attribution
Non-commercial. Published version is copyrighted and available at Wiersma YF. 2007. The effect
of target extent on the location of optimal protected areas networks in Canada Landscape
Ecology 22: 1477-1487. doi: 10.1007/s10980-007-9126-2
23
Figure 5.
4
Scale and protected areas networks, Wiersma, Y.F., page 24
Original paper published in Landscape Ecology (DOI: 10.1007/s10980-007-9126-2)
This version is a postprint. It has the same peer-reviewed content as the published version, but
lacks publisher layout and branding. It is available under License Creative Commons Attribution
Non-commercial. Published version is copyrighted and available at Wiersma YF. 2007. The effect
of target extent on the location of optimal protected areas networks in Canada Landscape
Ecology 22: 1477-1487. doi: 10.1007/s10980-007-9126-2
24
Figure 6.
Scale and protected areas networks, Wiersma, Y.F., page 25
Original paper published in Landscape Ecology (DOI: 10.1007/s10980-007-9126-2)
This version is a postprint. It has the same peer-reviewed content as the published version, but
lacks publisher layout and branding. It is available under License Creative Commons Attribution
Non-commercial. Published version is copyrighted and available at Wiersma YF. 2007. The effect
of target extent on the location of optimal protected areas networks in Canada Landscape
Ecology 22: 1477-1487. doi: 10.1007/s10980-007-9126-2
25
References
Cowling R.M., Pressey R.L., Rouget M. and Lombard A.T. 2003. A conservation plan for
a global biodiversity hotspot – the Cape Floristic Region, South Africa. Biological
Conservation 112: 191-216.
4
Erasmus B.F.N., Freitag S., Gaston K.J., Erasmus B.H. and van Jaarsveld A.S. 1999.
Scale and conservation planning in the real world. Proceedings of the Royal
Society of London, Series B 266: 315-319.
Glenn S.M. 1990. Regional analysis of mammal distributions among Canadian parks –
8
implication for park planning. Canadian Journal of Zoology 68: 2457-2464.
Glenn S.M. and Nudds T.D. 1989. Insular biogeography of mammals in Canadian parks.
Journal of Biogeography 16: 261-268.
Gurd D.B. and Nudds T.D. 1999. Insular biogeography of mammals in Canadian parks: a
12
re-analysis. Journal of Biogeography 26: 973-982.
Gurd D.B., Nudds T.D. and Rivard D.H. 2001. Conservation of mammals in eastern
North American wildlife reserves: how small is too small? Conservation Biology
15: 1355-1363.
16
Hagmeier E.M. 1966. A numerical analysis of the distributional patterns of North
American mammals. II. Re-evaluation of the provinces. Systematic Zoology 15:
279-299.
Humphreys W.F. and Kitchener D.J. 1982. The effect of habitat utilization on species-
20
area curves: implications for optimal reserve area. Journal of Biogeography 9:
391-396.
Scale and protected areas networks, Wiersma, Y.F., page 26
Original paper published in Landscape Ecology (DOI: 10.1007/s10980-007-9126-2)
This version is a postprint. It has the same peer-reviewed content as the published version, but
lacks publisher layout and branding. It is available under License Creative Commons Attribution
Non-commercial. Published version is copyrighted and available at Wiersma YF. 2007. The effect
of target extent on the location of optimal protected areas networks in Canada Landscape
Ecology 22: 1477-1487. doi: 10.1007/s10980-007-9126-2
26
Kerley G.I.H., Pressey R.L., Cowling R.M., Boshoff A.F. and Sims-Castley R. 2003.
Options for the conservation of large and medium-sized mammals in the Cape
Floristic Region hotspot, South Africa. Biological Conservation 112: 169-190.
Kunin W.E. 1997. Sample shape, spatial scale and species counts: implications for
4
reserve design. Biological Conservation 82: 369-377.
Margules C.R., Nicholls A.O. and Pressey R.L. 1988. Selecting networks of reserves to
maximize biological diversity. Biological Conservation 43: 63-76.
McDonald R., McKnight M., Weiss D., Selig E., O’Connor M., Violin C. and Moody A.
8
2005. Species compositional similarity and ecoregions: Do ecoregion boundaries
represent zones of high species turnover? Biological Conservation 126: 24-40.
Oswald E.T. and Senyk J.P. 1977. Ecoregions of the Yukon Territory. Publication BC-X-
164, Canadian Forest Service, Environment Canada, Victoria, British Columbia,
12
Canada.
Palmer M.W. and White P.S. 1994. Scale dependence and the species-area relationship.
The American Naturalist 144: 717-740.
Patterson B.D., Ceballos G., Sechrest W., Tognelli M.F., Brooks T., Luna L., Ortega P.,
16
Salazar I. and Young B.E. 2003. Digital Distribution Maps of the Mammals of the
Western Hemisphere, version 1.0. NatureServe, Arlington, Virginia, USA.
Pressey R.L. and Nicholls A.O. 1989. Application of a numerical algorithm to the
selection of reserves in semi-arid New South Wales. Biological Conservation 50:
20
263-278.
Scale and protected areas networks, Wiersma, Y.F., page 27
Original paper published in Landscape Ecology (DOI: 10.1007/s10980-007-9126-2)
This version is a postprint. It has the same peer-reviewed content as the published version, but
lacks publisher layout and branding. It is available under License Creative Commons Attribution
Non-commercial. Published version is copyrighted and available at Wiersma YF. 2007. The effect
of target extent on the location of optimal protected areas networks in Canada Landscape
Ecology 22: 1477-1487. doi: 10.1007/s10980-007-9126-2
27
Pressey R.L., Humphries C.J., Margules C.R., Van-Wright R.I. and Williams P.H. 1993.
Beyond opportunism: key principles for systematic reserve selection. Trends in
Ecology and Evolution 8: 124-128.
Pressey R.L., Watts M.E. and Barrett T.W. 2004. Is maximizing protection the same as
4
minimizing loss? Efficiency and retention as alternative measures of the
effectiveness of proposed reserves. Ecology Letters 7: 1035-1046.
Purchase D. 2003. The Northwest Territories protected areas strategy: background. In
Wiersma Y.F (ed.), Designing Protected Areas: Wild Places for Wildlife:
8
Proceedings summary of the 2003 Canadian Council on Ecological Areas
(CCEA) and Circumpolar Protected Areas Network (CPAN) Workshop pp. 52-55.
Canadian Council on Ecological Areas, Ottawa, Ontario, Canada.
Rodrigues A.S.L. and Gaston K.J. 2002. Rarity and conservation planning across
12
geopolitical units. Conservation Biology 16: 674-682.
Rouget M. 2003. Measuring conservation value at fine and broad scales: implications for
a diverse and fragmented region, the Agulhas Plain. Biological Conservation 112:
217-232.
16
Stoms D.M., Chomitz K.M. and Davis F.W. 2004. TAMARIN: a landscape framework
for evaluating economic incentives for rainforest restoration. Landscape and
Urban Planning 68: 95-108.
Turner M.G., Gardner R.H. and O’Neill R.V. 2001. Landscape ecology in theory and
20
practice. Springer-Verlag, New York, USA.
Verburg P.H. and Veldkamp A. 2004. Projecting land use transitions at forest fringes in
the Philippines at two spatial scales. Landscape Ecology 19: 77-98.
Scale and protected areas networks, Wiersma, Y.F., page 28
Original paper published in Landscape Ecology (DOI: 10.1007/s10980-007-9126-2)
This version is a postprint. It has the same peer-reviewed content as the published version, but
lacks publisher layout and branding. It is available under License Creative Commons Attribution
Non-commercial. Published version is copyrighted and available at Wiersma YF. 2007. The effect
of target extent on the location of optimal protected areas networks in Canada Landscape
Ecology 22: 1477-1487. doi: 10.1007/s10980-007-9126-2
28
Warman L.D., Forsyth D.M., Sinclair A.R.E., Freemark K., Moore H.D., Barrett T.W.,
Pressey R.L. and White D. 2004. Species distributions, surrogacy, and important
conservation regions in Canada. Ecology Letters 7: 374-379.
Wiens J.A. 1989. Spatial scaling in ecology. Functional Ecology 3: 385-397.
4
Wiersma Y.F. and Nudds T.D. 2004. On the fraction of land needed for protected areas.
In Munro N.W.P., Dearden P., Herman T.B., Beazly K. and Bondrup-Nielson S.
(eds.), Making Ecosystem Based Management Work: connecting managers and
researchers. Proceedings of the Fifth International Conference on Science and
8
Management of Protected Areas, Chapter 7, CD-ROM proceedings. Wolfville,
Nova Scotia, Canada.
Wiersma Y.F. and Nudds T.D. In press. Conservation targets for viable species
assemblages in Canada: are percentage targets appropriate? Biodiversity and
12
Conservation.
Wiersma Y.F. and Urban D.L. 2005. Beta diversity and nature reserve system design: a
case study from the Yukon. Conservation Biology 19: 1262-1272.
Wiken E.B., Gauthier D., Marshall I., Lawton K.and Hirvonen H. 1996. A Perspective on
16
Canada’s Ecosystems: An Overview of the Terrestrial and Marine Ecozones.
Canadian Council on Ecological Areas (CCEA). Occasional Paper No. 14.
Ottawa, Ontatio, Canada.
YPAS (Yukon Protected Areas Strategy). 1998. Types of protected areas and criteria for
20
selection. Technical Paper No. 2. Department of Renewable Resources, Yukon
Government, Canada.
... "How much to protect" has been a pressing question for conservation biologists in both the academic and practitioner literature 1 . Research questions related to systematic conservation planning (SCP) have focused on evaluations of how different target types (such as percentage of land area or proportion of populations) 2,3 and amounts (e.g., 12% vs. 50% of land area) [4][5][6] , effects of scale 7,8 , planning unit size 9 and data characteristics 10,11 affect conservation planning outcomes. For example, researchers have examined how the scale at which planning takes place affects the number and location of protected areas needed to capture a representative proportion of biodiversity [7][8][9] . ...
... Research questions related to systematic conservation planning (SCP) have focused on evaluations of how different target types (such as percentage of land area or proportion of populations) 2,3 and amounts (e.g., 12% vs. 50% of land area) [4][5][6] , effects of scale 7,8 , planning unit size 9 and data characteristics 10,11 affect conservation planning outcomes. For example, researchers have examined how the scale at which planning takes place affects the number and location of protected areas needed to capture a representative proportion of biodiversity [7][8][9] . A critical question for conservation planners is whether there are guidelines for a fixed percentage of land area that should be set aside for conservation that can ensure that all species are adequately represented 1,2 . ...
Model systems to elucidate minimum requirements for protected areas networks
Article
Full-text available
  • Dec 2019
In conservation biology there have been varying answers to the question of “How much land to protect?” Simulation models using decision-support software such as Marxan show that the answer is sensitive to target type and amount, and issues of scale. We used a novel model system for landscape ecology to test empirically whether the minimum conservation requirements to represent all species at least once are consistent across replicate landscapes, and if not, whether these minimum conservation requirements are linked to biodiversity patterns. Our model system of replicated microcosms could be scaled to larger systems once patterns and mechanisms are better understood. We found that the minimum representation requirements for lichen species along the microlandscapes of tree trunks were remarkably consistent (4–6 planning units) across 24 balsam fir trees in a single stand, as well as for 21 more widely dispersed fir and yellow birch trees. Variation in minimum number of planning units required correlated positively with gamma diversity. Our results demonstrate that model landscapes are useful to determine whether minimum representation requirements are consistent across different landscapes, as well as what factors (life history, diversity patterns, dispersal strategies) affect variation in these conservation requirements. This system holds promise for further investigation into factors that should be considered when developing conservation designs, thus yielding scientifically-defensible requirements that can be applied more broadly.
... Despite this, and other, empirical work by others (Wiersma and Nudds 2006;Justus et al. 2008) that shows the problematic nature of uniformly-applied percentage targets, such targets are still used. A more recent review (Wiersma and Sleep 2016) found that percentage targets are still widely applied without empirical justification, and environmental groups have moved beyond calling for 12% protection of habitat (Hummell 1995) or advocating for the Aichi Target of 17% (Target 11; Convention on Biodiversity 2010) to suggesting that 50% might be a more appropriate target in areas of the globe which represent near-intact wilderness areas, such as the Canadian boreal forest region (CPAWS 2008;Baidou et al. 2013;Wells et al. 2014;Dinerstein et al. 2017). However, this new target is not based on empirical evidence, but rather appears to draw largely on two opinion pieces by prominent conservation advocates (Noss et al. 2012;Locke 2013) who have suggested arbitrary large targets, due to concerns that existing protected areas may not be sufficient to maintain global biodiversity, and an interest in concentrating their efforts on near-intact wilderness areas. ...
... Target 1-conserve a fixed percentage of the landscape This rule mimics broad conservation targets, which Svancara et al. (2005) labelled ''data free''. We set percentage targets at four different levels: 10, 35, 50, and 60% to capture the range of percentages advocated by environmental groups (e.g., Hummell 1995;CPAWS 2008;Baidou et al. 2013;Wells et al. 2014) and values advocated in the conservation biology literature (e.g., Solomon et al. 2003). ...
The effect of target setting on conservation in Canada’s boreal: what is the right amount of area to protect?
Article
Full-text available
Conservation of Canada’s boreal forest has been tied to various campaigns advocating specific area-based targets as part of a broader Systematic Conservation Planning (SCP) effort. Although target setting is an important component of SCP, it is known that the final outcomes of conservation plans are sensitive to the target chosen. There have been few systematic evaluations of how these outcomes change with targets. Here, we use distribution of terrestrial mammals in the Boreal Shield Ecozone of Canada to assess the effects of targets on conservation plans with individual sites that are predicted to be large enough to allow for species persistence. We examine three types of targets; percentage of landscape, percentage of umbrella species range, and minimum number of sites, to see how the final set (in terms of numbers of sites and percent of land) is affected and how well the final set represents the full suite of mammal species. We found a large discrepancy (164,000 km²) in the land required to achieve minimal representation targets depending on the target used. The minimum number of sites target was most efficient and required only 1.25% of the ecozone, while the smallest percentage target that could capture all species was 10%. The use of an umbrella species (caribou, Rangifer tarandas) range was the least effective target, as several species could not be represented at any percentage of the umbrella species range. Thus, conservation planners working in the boreal should be mindful of the impacts their targets have on the final design.
... The spatial extent of conservation planning assessments has varied from global (Brooks et al., 2004), continental (Carwardine et al., 2008) or finer regional scales such as individual river basins (Hermoso et al., 2011a), islands (Payet et al., 2010) or political boundaries (Amis et al., 2009). The spatial extent of the planning exercise influences not only the spatial allocation of priority areas, but also the efficiency of the conservation plan and feasibility of its implementation (Wiersma, 2007; Vazquez et al., 2008). Broad-scale assessments outperform small-scale ones in terms of efficiency. ...
... Previous literature has focused on the evaluation of the effect of the size of planning units on the efficiency of priority areas to represent biodiversity ( Logan, 1994, 1995; Rouget, 2003). However, little is known about other spatial related issues, such as the effect of varying resolution species distribution data, or the implications of these factors on other measures of the performance of conservation outputs apart from the well-studied effects on efficiency (Wiersma, 2007; Vazquez et al., 2008). Here, we show that the influence of the choice of grain size of both planning units and species distribution data extends beyond assessment of efficiency and that the achievement of conservation goals could be seriously compromised by commission errors and uncertainty in the distribution of species associated with coarse grained assessments. ...
Uncertainty in coarse conservation assessments hinders the efficient achievement of conservation goals
Article
Conservation planning is sensitive to a number of scale-related issues, such as the spatial extent of the planning area, or the size of units of planning. An extensive literature has reported a decline in efficiency of conservation outputs when planning at small spatial scales or when using large planning units. However, other key issues remain, such as the grain size used to represent the spatial distribution of conservation features. Here, we evaluate the effect of grain size of species distribution data versus size of planning units on a set of performance measures describing efficiency (ratio of area where species are represented/total area needed), rate of commission errors (species erroneously expected to occur), representativeness (proportion of species achieving the target) and a novel measure of overall conservation uncertainty (integrating commission errors and uncertainty in the actual locations where species occur). We compared priority areas for the conservation of freshwater fish in the Daly River basin (northern Australia). Our study demonstrates that the effect of grain size of species distribution data was more important than planning unit size on conservation planning performance, with an increase in commission errors up to 80% and conservation uncertainty over 90% when coarse data were used. This was more pronounced for rare than common species, where the mismatch between coarse representations of biodiversity patterns and the smaller areas of actual occupancy of species was more evident. Special attention should be paid to the high risk of misallocation of limited budgets when planning in heterogeneous or disturbed environments, where biodiversity is patchily distributed, or when planning for conservation of rare species.
... For example, Warman et al. (2004) examined the influence of data grain by comparing the spatial similarity (% overlap) of selected sets of conservation sites for 29 threatened vertebrate species between different sizes of planning units and found that they overlapped by 640%. Wiersma (2007) also examined the influence of carrying study area extent, and found that a larger regional extent required fewer protected areas to meet conservation targets than was required to meet the same targets within several smaller extents. ...
... Our study provides a unique contribution to the burgeoning literature on the use of site selection algorithms to identify priority biodiversity areas, and previous work in the Y2Y region specifically, for four reasons. First, we investigate the effect of varying the scale of the target region on the location of priority areas, which has rarely been done (see Wiersma 2007 for another recent example). Second, unlike previous studies in Y2Y where the focus has been on mammalian carnivores, we consider the conservation of birds. ...
Prioritizing avian conservation areas for the Yellowstone to Yukon Region of North America
Article
Prioritizing new areas for conservation in the Rocky Mountains of North America is important because the current intensity and scale of human development poses an immediate threat to biodiversity. We identified priority areas for avian biodiversity within a 3200-km corridor from Yellowstone National Park in Wyoming, US to the Yukon in Canada (the Y2Y region). We applied the conservation planning tool, MARXAN, to summarize 21 avian values. MARXAN minimizes the area delineated, while simultaneously incorporating multiple criteria (species richness representation, spatial clustering) and biodiversity targets into a single mappable solution. We prioritized avian biodiversity ‘hotspots’ at continental and ecoprovincial scales based on: (1) avian species richness; and (2) habitat associations of 20 focal species. At the continental scale, the single best solution represented 19% of the Y2Y region; 29% of this solution overlapped with existing protected areas. In northern Y2Y, large contiguous areas with high avian value were concentrated on the western edge of the continental divide. In southern Y2Y, contiguous areas were smaller and more numerous than in the north. In contrast to the majority of studies prioritizing conservation areas, we explored the effect of varying the extent of the target region by analyzing data at the scale of the entire Y2Y region and for eight ecoprovinces separately. We found that (1) large contiguous patches characterized only three ecoprovinces, while for the remaining ecoprovinces, numerous single scattered habitat patches of varying sizes were required to meet conservation goals; and (2) generally, only a small percentage of sites was already protected within the existing protected areas network. Our results are important for conservation planners and resource managers in the Y2Y region for incorporating areas of high conservation value for birds at regional and ecoprovincial scales during conservation project design and adaptive planning.
... With respect to climate change, our results echoed those of other studies (Carroll et al. 2010, Powers et al. 2017, where including future climate did not improve efficiency, likely because of geographic divergence of species' ranges over time. Similarly, scenarios that were stratified by bird conservation subregion also yielded lower efficiency scores, demonstrating that optimality is lost when solutions are forced to be equally distributed across regions, consistent with findings by Wiersma (2007) for Canadian mammals. This presents trade-offs between efficiency and geographic representation that planners must navigate. ...
Strategies for identifying priority areas for songbird conservation in Canada's boreal forest
Article
Full-text available
  • Dec 2018
Canada's boreal forest region is among the most extensive and largely intact ecosystems on earth, but has experienced rapid industrial development in the last half-century. Calls for urgent conservation action have been prompted by the increasing pace of development and declines in biodiversity, including songbirds. To assist conservation decision making, we introduce a framework to facilitate selection of the highest priority areas for a given conservation objective. We varied six key decision points representing possible constraints or a priori conservation factors: (1) prioritization metric (species representation vs. diversity), (2) geographic stratification, (3) degree of anthropogenic disturbance, (4) species' conservation status, (5) species' ecological association, and (6) climate-change and uncertainty discounting. Using the Zonation conservation planning tool, we evaluated landbird conservation priorities across 128 scenarios for 63 passerine species based on current and projected future density predictions. We compared Zonation land rankings across scenarios with respect to consistency, efficiency (additive and proportional conservation value per unit area), and the relative contributions of each of the six factors of interest. We found large differences between solutions depending on constraints and conservation objectives, and relatively low conservation efficiency overall, with the largest gains in overall conservation value observed in areas ranging from 0.31-0.56 of the study region. This reflects the large range of conservation opportunities still present in the Canadian boreal region, and the widely dispersed nature of landbird distributions, which results in high substitutability among similar areas. However, we did find increasing consistency among solutions as multiple constraints were considered. In particular, stratifying solutions geographically resulted in more consistent priorities, although at the expense of efficiency. Other constraints, including climate change, disturbance-and uncertainty-discounting, and the selection and weighting of species, helped to further focus priorities. Although no single scenario can be viewed as prescriptive, we provide a roadmap for prioritizing boreal songbird conservation efforts across multiple conservation objectives. Stratégies visant l'identification d'endroits prioritaires pour la conservation de passereaux en forêt boréale canadienne RÉSUMÉ. La région de la forêt boréale du Canada figure parmi les écosystèmes les plus vastes et les plus intacts de la planète, mais elle a connu une exploitation industrielle rapide au cours du dernier demi-siècle. Le rythme croissant d'exploitation et de diminution de la biodiversité, dont les oiseaux chanteurs, a mené à des appels urgents à l'action pour la conservation. Pour guider la prise de décision en conservation, nous proposons un cadre facilitant la sélection des endroits prioritaires les plus importants pour un objectif de conservation donné. Nous avons fait varier six points clés de décision représentant des contraintes possibles ou des facteurs de conservation a priori : (1) paramètre de priorisation (représentation de l'espèce c. sa diversité), (2) stratification géographique, (3) degré de dérangement humain, (4) statut de conservation de l'espèce, (5) association écologique de l'espèce, et (6) changement climatique et réduction de l'incertitude. Au moyen du logiciel de planification de la conservation Zonation, nous avons évalué les priorités de conservation d'oiseaux terrestres parmi 128 scénarios pour 63 espèces de passereaux, en nous fondant sur les densités actuelles et des prédictions de densités futures. Nous avons comparé la priorisation terrestre des scénarios faite par Zonation selon la cohérence, l'efficacité (valeur de conservation par unité additive et proportionnelle) et la contribution relative de chacun des six facteurs d'intérêt. Nous avons obtenu de grandes différences entre les solutions en fonction des contraintes et des objectifs de conservation, et une efficacité de conservation relativement faible dans l'ensemble, les gains les plus grands de la valeur globale de conservation observés dans divers endroits allant de 0,31 à 0,56 de la région d'étude. Ce résultat reflète la gamme étendue d'occasions de conservation encore présentes dans la région boréale canadienne et le caractère fort dispersé de la répartition des oiseaux terrestres, résultant en un potentiel élevé de substitution parmi les endroits similaires. Toutefois, nous avons trouvé une cohérence croissante parmi les solutions parce que de particulièrement, la stratification géographique des solutions menait à des priorités plus cohérentes, mais aux dépens de l'efficacité. D'autres contraintes, dont le changement climatique, la réduction du dérangement et de l'incertitude, et la sélection et la pondération des espèces, ont contribué à préciser davantage les priorités. Même si aucun des scénarios ne peut être qualifié de prescriptif, nous fournissons un cadre destiné à prioriser les efforts de conservation des oiseaux chanteurs boréaux en présence de nombreux objectifs de conservation.
... Due to the continuous yet variable nature of distribution of biodiversity features, conservation prioritization separately for each administrative region will inevitably waste resources as compared with analyses across regions (Erasmus et al., 1999;Strange et al., 2006;Wiersma, 2007;Vazquez et al., 2008;Bladt et al., 2009;Kark et al., 2009). On the other hand, a global analysis across all regions is likely to focus resources on regions with highest diversity or endemism, while other regions may be left entirely without resources, which may not be politically acceptable. ...
Administrative regions in conservation: Balancing local priorities with regional to global preferences in spatial planning
Article
Site selection, reserve selection, and spatial conservation prioritization are terms that have been used for various algorithms and methods for the spatial allocation of conservation resources. Many of these methods start from the setting of targets or weights for different conservation features. Almost always there is only one set of targets or weights, thus implicitly assuming that priorities stay the same through the entire planning region. However, priorities for biodiversity governance could vary between regions. For example, priorities inside countries could be different from global priorities. Inside a country, different stakeholders could hold different priorities. Thus, priorities could vary between sub-regions while ecological processes, such as connectivity, cross borders without regard to administrative boundaries. Here we describe how it is possible to account for conservation priorities that vary between administrative sub-regions in conservation prioritization. We illustrate how assumptions about selection methods and feature weights can significantly influence the outcome mapping of conservation priority. We also show how placing high emphasis on local considerations reduces the cost-efficiency of the global conservation outcome. Analyses proposed here will be made publicly available in software (Zonation) capable for large-scale high-resolution conservation prioritization.
... One method for creating a regional conservation plan begins by identification of important core areas that contain regionally important habitats and ecological features (Noss et al. 1999;Margules and Pressey 2000). These features might include rare or sensitive species (Rothley 1999;Wiersma 2007), high biodiversity (Margules et al. 1988;Prendergast et al. 1993;Shriner et al. 2006), and ecological processes (Turner et al. 1999). Another conservation planning approach is the use of focal species (Lambeck 1997;Wiens et al. 2008), in which a species considered to be the most sensitive to perturbation of a particular ecosystem pattern or process is used as a surrogate (or ''umbrella'') in the conservation planning process for other species sensitive to disturbance of the same ecosystem components. ...
Spatial scale effects on conservation network design: Trade-offs and omissions in regional versus local scale planning
Article
Full-text available
  • May 2010
Ecological patterns and processes operate at a variety of spatial scales. Those which are regional in nature may not be effectively captured through the combination of conservation plans derived at the local level, where land use planning frequently takes place. Conversely, regional conservation plans may not identify resources important for conservation of intraregional ecological variation. We compare modeled conservation networks derived at regional and local scales from the same area in order to analyze the impact of scale effects on conservation planning. Using the MARXAN reserve selection algorithm and least cost corridor analysis we identified a potential regional conservation network for the Central Valley ecoregion of California, USA, from which we extracted those portions found within five individual counties. We then conducted the same analysis for each of the five counties. An overlay of the results from the two scales shows a general pattern of large differences in the identified networks. Especially noteworthy are the trade-offs and omissions evident at both scales of analysis and the disparateness of the identified corridors that connect core reserves. The results suggest that planning efforts limited to one scale will neglect biodiversity patterns and ecological processes that are important at other scales. An intersection of results from the two scales can potentially be used to prioritize areas for conservation found to be important at several spatial scales. KeywordsConnectivity-Reserve selection-Conservation planning-Central Valley-California-Ecoregion-MARXAN-Scale effects-Corridor
... The overall aim of a network of protected areas is to represent regional biodiversity, including key species, landforms, and natural communities present within a local environment (Wiersma 2007). Specifically, Canada's national parks are designed to protect the habitats, wildlife, and ecosystem diversity representative of (and sometimes unique to) Canada's natural regions (Parks Canada 2009). ...
Characterizing the forest fragmentation of Canada’s national parks
Article
  • Apr 2010
Characterizing the amount and configuration of forests can provide insights into habitat quality, biodiversity, and land use. The establishment of protected areas can be a mechanism for maintaining large, contiguous areas of forests, and the loss and fragmentation of forest habitat is a potential threat to Canada’s national park system. Using the Earth Observation for Sustainable Development of Forests (EOSD) land cover product (EOSD LC 2000), we characterize the circa 2000 forest patterns in 26 of Canada’s national parks and compare these to forest patterns in the ecological units surrounding these parks, referred to as the greater park ecosystem (GPE). Five landscape pattern metrics were analyzed: number of forest patches, mean forest patch size (hectare), standard deviation of forest patch size (hectare), mean forest patch perimeter-to-area ratio (meters per hectare), and edge density of forest patches (meters per hectare). An assumption is often made that forests within park boundaries are less fragmented than the surrounding GPE, as indicated by fewer forest patches, a larger mean forest patch size, less variability in forest patch size, a lower perimeter-to-area ratio, and lower forest edge density. Of the 26 national parks we analyzed, 58% had significantly fewer patches, 46% had a significantly larger mean forest patch size (23% were not significantly different), and 46% had a significantly smaller standard deviation of forest patch size (31% were not significantly different), relative to their GPEs. For forest patch perimeter-to-area ratio and forest edge ensity, equal proportions of parks had values that were significantly larger or smaller than their respective GPEs and no clear trend emerged. In summary, all the national parks we analyzed, with the exception of the Georgian Bay Islands, were found to be significantly different from their corresponding GPE for at least one of the five metrics assessed, and 50% of the 26 parks were significantly different from their respective GPEs for all of the metrics assessed. The EOSD LC 2000 provides a heretofore unavailable dataset for characterizing broad trends in forest fragmentation in Canada’s national parks and in their surrounding GPEs. The interpretation of forest fragmentation metrics must be guided by the underlying land cover context, as many forested ecosystems in Canada are naturally fragmented due to wetlands and topography. Furthermore, interpretation must also consider the management context, as some parks are designed to preserve fragmented habitats. An analysis of forest pattern such as that described herein provides a baseline, from which changes in fragmentation patterns over time could be monitored, enabled by earth observation data. Keywords: Forest fragmentation, Landsat, Canada, national parks, ecosystem
... Under our demographic model (Table 1;Fig. 4), eastern wolves and coyotes split between 150,000 and 300,000 years ago (T.split) (Wilson et al. 2000) and were separated until 100 years ago when the first coyotes were reported in southern Ontario (Nowak 1979 Berger and Conner 2008]) was also modeled to remain stable until 100 years ago (T.bot) when a small number of individuals (Kays et al. 2010 Wiersma 2007]). After this founding population arrived, we allowed constant asymmetric gene flow (0.1–5%) from coyotes in FRAX into wolves in APP. ...
Intense harvesting of eastern wolves facilitated hybridization with coyotes
Article
Full-text available
  • Jan 2012
Despite ethical arguments against lethal control of wildlife populations, culling is routinely used for the management of predators, invasive or pest species, and infectious diseases. Here, we demonstrate that culling of wildlife can have unforeseen impacts that can be detrimental to future conservation efforts. Specifically, we analyzed genetic data from eastern wolves (Canis lycaon) sampled in Algonquin Provincial Park (APP), Ontario, Canada from 1964 to 2007. Research culls in 1964 and 1965 killed the majority of wolves within a study region of APP, accounting for approximately 36% of the park's wolf population at a time when coyotes were colonizing the region. The culls were followed by a significant decrease in an eastern wolf mitochondrial DNA (mtDNA) haplotype (C1) in the Park's wolf population, as well as an increase in coyote mitochondrial and nuclear DNA. The introgression of nuclear DNA from coyotes, however, appears to have been curtailed by legislation that extended wolf protection outside park boundaries in 2001, although eastern wolf mtDNA haplotype C1 continued to decline and is now rare within the park population. We conclude that the wolf culls transformed the genetic composition of this unique eastern wolf population by facilitating coyote introgression. These results demonstrate that intense localized harvest of a seemingly abundant species can lead to unexpected hybridization events that encumber future conservation efforts. Ultimately, researchers need to contemplate not only the ethics of research methods, but also that future implications may be obscured by gaps in our current scientific understanding.
Efficiency and effectiveness in representative reserve design in Canada: The contribution of existing protected areas
Article
To be effective, reserve networks should represent all target species in protected areas that are large enough to ensure species persistence. Given limited resources to set aside protected areas for biodiversity conservation, and competing land uses, a prime consideration for the design of reserve networks is efficiency (the maximum biodiversity represented in a minimum number of sites). However, to be effective, networks may sacrifice efficiency. We used reserve selection algorithms to determine whether collections of existing individual protected areas in Canada were efficient and/or effective in terms of representing the diversity of disturbance-sensitive mammals in Canada in comparison to (1) an optimal network of reserves, and (2) sites selected at random. Unlike previous studies, we restricted our analysis to individual protected areas that met a criterion for minimum reserve size, to address issues of representation and persistence simultaneously. We also tested for effectiveness and efficiency using historical and present-day data to see whether protected area efficiency and/or effectiveness varied over time. In general, existing protected areas did not effectively capture the full suite of mammalian species diversity, nor are most existing protected areas part of a near-optimal solution set. To be effective, Canada’s network of reserves will require at minimum 22 additional areas of >2700 km2. This study shows that even when only those reserves large enough to be effective are considered, protected areas systems may not be representative, nor were they representative at the time of establishment.
Scaling and Uncertainty Analysis in Ecology: Methods and Applications
Book
Full-text available
  • Jan 2006
Landscape Ecology in Theory and Practice
Article
Landscape Ecology
Article
The Effect of Habitat Utilization on Species-Area Curves: Implications for Optimal Reserve Area
Article
  • Sep 1982
The biological reserves in the wheatbelt of Western Australia form islands of native vegetation in a sea of arable farmland. Subdivision of the species in three vertebrate taxa (mammals, passerine birds and lizards) into species retained only in reserves (u species) and those also surviving outside the reserves in disturbed areas (d species) show conflicting requirements for reserve area. In each taxon u species are lost disproportionately with a reduction in area. The d species are favoured by more smaller reserves while u species, those most in need of conservation, are favoured by larger reserves.
Insular Biogeography of Mammals in Canadian Parks
Article
  • May 1989
Using range maps depicting mammal distributions in Canada prior to European settlement, species-area curves with confidence limits were constructed for each of six regions where species composition of mammals was faunistically homogeneous. The number of species in parks was compared to the number predicted to have been present in an area of equivalent size during the pre-settlement era. In the densely populated region comprising southern Ontario, southern Quebec, and the maritimes, and consistent with predictions from island biogeography theory, parks presently have fewer species that require undisturbed habitats than were predicted to have been present prior to settlement. The difference between the number of species observed and predicted is greater for small than large parks. In all other regions, most parks had the same or more species than predicted. It appears that greater numbers of species in some parks may be due either to alteration of habitats (e.g. fire suppression in prairie parks) or siting parks in species-rich areas.
A Numerical Analysis of the Distributional Patterns of North American Mammals. II. Re-evaluation of the Provinces
Article
In an earlier paper, numerical techniques were developed and used to analyze distribution patterns of the native terrestrial mammals of North America. An error in method is here corrected, indicating that 35 provinces, 13 superprovinces, four subregions, and one region may be recognized. The methods used are relatively objective, quantitative, and suited to computerization.
Nature grows in straight lines - Or does she? What are the consequences of the mismatch between human-imposed linear boundaries and ecosystem boundaries? An Australian example
Article
Sustainability in agricultural landscapes means that the use and management of ecological potential does not reduce its capacity to meet society’s future environmental, social and economic needs. Using this description of sustainability, Australian agricultural systems are far from sustainable at present. Removal of vast areas of native vegetation and the introduction of inappropriate agricultural systems have resulted in extensive loss of native biota, loss of productive agricultural land and decline in rural society. These degrading trends will continue to worsen unless Australian society intervenes on a broad scale. For example, to stop water tables from rising with attendant salination of soil, it has been estimated that over 30 billion perennial trees and shrubs will need to be planted. How does a society generate the will and ability to tackle environmental problems at this scale when its community and institutional boundaries do not reflect ecological reality? This paper discusses these issues and concludes with a 10-point plan to guide development of an approach to sustainable landscapes.
Options for the conservation of large and medium-sized mammals in the Cape Floristic Region hotspot, South Africa
Article
We assessed options for conserving the large- and medium-sized mammals indigenous to the Cape Floristic Region, South Africa, using systematic conservation planning, the first such attempt for an entire ecoregion. The potential distributions and abundances of the 41 extant species for the entire region prior to anthropogenic transformation of habitats were estimated. This was particularly useful as it obviated any reliance on records of occurrence for conservation planning. Areas that had not been transformed through agriculture or other developments were considered available for conservation. The fragments of untransformed habitat were identified as being large enough to support communities at least 25 individuals of the smallest herbivore species. Smaller fragments were not considered suitable for mammal conservation. Transformation and fragmentation had significant impacts on potential populations, and this was asymmetrical across species, being higher for lowland than montane species. The existing reserve system was estimated to effectively conserve only half the mammal species, using the criteria applied here. Two conservation goals were compared; first, either conserving only CFR endemics and threatened species; and second, conserving all the mammals (with some exceptions for marginally occurring species). Options for protected area systems were assessed using C-Plan, a decision support system designed for systematic conservation planning. The irreplaceability of the planning units varied only slightly under the two goals, and the more inclusive goal was used to develop a proposed reserve network in which targets for all the species were achieved. The CFR endemics and threatened species effectively function as umbrella species for the remaining mammals. This study demonstrates that the incorporation into systematic conservation plans of conservation targets adequate for the persistence of populations comprising communities across entire ecoregions is feasible.
Scaling and Uncertainty Analysis inEcology
Book
  • Jan 2006
Regional ecology, ecosystem geography, and transboundary protected areas in the St. Elias Mountains
Article
  • Apr 2005
This study characterizes the broad-scale ecology of the St. Elias region of Yukon, Alaska, and British Columbia and assesses the implications for ecosystem-based management of the region's protected areas, including Kluane, Wrangell-St. Elias, and Glacier Bay National Parks, and Tatshenshini-Alsek Provincial Park. An interdisciplinary, map-based process was used to synthesize information, and the fields of regional ecology and ecosystem geography provided the foundation for analysis. Results illustrate that the protected areas share several regional-scale ecosystem components with each other and with surrounding areas, including globally significant populations of large mammals and other wildlife species as well as vegetation communities that experience a full suite of natural disturbances with little human intervention. The valleys of the Tatshenshini, Alsek, and Copper Rivers serve as important links between coastal and interior areas as well as conduits for the movement of biota. However, connectivity is not distributed equally across the region, and the four core national parks have. linkages with adjacent areas that are as strong, and in many cases stronger, than among themselves. The management challenge is not a matter of linking separate protected areas to create networks. Instead, it lies in integrating existing protected areas with each other and with surrounding areas and resisting small changes that have incremental and cumulative impacts. Interagency cooperation is seen as a key component in facilitating this, and some success has been achieved on the scale of single issues and specific resources. The challenge ahead is to build on this success by strengthening existing institutional frameworks and working toward more comprehensive efforts. Similar lessons can be derived for other complex mountain landscapes and northern regions where large protected areas and multiple land management agencies exist.