Conservation planning in a changing world
183
action in space and time that can deliver conservation
outcomes. In this section we focus most of our attention on reserve system design in a dynamic world.
However, these thoughts are relevant to other sorts of
spatially - explicit conservation action. We close with a
discussion on applying dynamic conservation planning in response to future climate change.
7.4.1 Incorporating d ynamic b iotic and
a biotic p rocesses into c onservation p lans
The distribution of the conservation features that we
are trying to conserve, usually species or habitat types,
will change over time (Box 7.4 ). Dedicating a site as a
reserve may affect the likelihood of losing a conservation feature from an area, or affect the time period over
which the loss takes place. Species ’ distributions, in
particular, can change rapidly, often in response to
predictable threats. Some of this change is associated
with human - induced threats, such as an invasive
species, habitat modifi cation, or anthropogenic climate
change, while other changes are ‘ natural ’ . The fi rst
question that we therefore need to consider is the
extent to which reserves can stop change, ameliorate
it, or do next to nothing to infl uence a changing
distribution.
Where a reserve does not ameliorate a threat, such
as a fl ood or a hurricane, then conservation planning
needs to consider two things: fi rst, how to set priorities
that preferentially conserve sites with low levels of
threat; and second, how much risk - spreading is necessary to provide adequate persistence in the face of that
threat (e.g. how many separate sites might be required
uncertainties involved to predict the rate and magnitude of extinctions in the 21st century accurately.
What we can say is that, despite the variation in performance of efforts to model climate - driven shifts in
species ’ geographical ranges, enormous changes in
species ’ distributions seem inevitable given substantial
climate change. While many biologists would probably
subscribe to this view, it is much less clear what actions
we can take to avert, or at least minimize, these future
extinctions as a result of climate change.
7.4 WHAT DO WE DO ABOUT IT?
DYNAMIC CONSERVATION PLANNING
Long - term ecology tells us that species ’ distributions
are highly dynamic, and our conservation response to
continuing human threats must be similarly dynamic
if it is to succeed. Biogeographers and ecologists have
already begun to use insights derived from past
changes, together with new statistical techniques, to
build predictions about the future changing patterns of
biodiversity. We have already argued that almost every
aspect of the conservation planning problem is
dynamic and that static conservation planning has its
limitations.
The question remains, what should we do about
this? The theory, and practice, of conservation planning in a dynamic world is in its infancy compared to
static conservation planning. It would nonetheless be
a hard task to cover every dynamic aspect of conservation planning, so here we introduce a few problems and
the ways they can be tackled. In its broadest sense,
dynamic conservation planning is about taking any
1 whether the distributional models capture the mechanisms controlling distribution;
2 assumptions made about the dispersal powers of the species;
3 a lack of consideration of the role of ecological interactions with other species;
4 huge uncertainty about the climate change models used in projecting the future distributions;
5 assumptions about how area losses might translate into overall numbers of species losses (Thuiller
et al. , 2004 ; Whittaker et al. , 2005 ; Ladle, 2009 ).
In respect of the last of these, see the further discussion of the use of the canonical species – area
value of z = 0.25 in projections of regional species losses in Section 8.2.1 .
Taking account of all of these sources of uncertainty, it quickly becomes apparent that the quantitative projections of losses provided by this study, although originally presented as a range of
values and subsequently widely cited in scientifi c, policy and popular discourse, are misleadingly
precise values that should be regarded as a conjecture rather than a forecast or prediction (Ladle
et al. , 2005 ).
183
action in space and time that can deliver conservation
outcomes. In this section we focus most of our attention on reserve system design in a dynamic world.
However, these thoughts are relevant to other sorts of
spatially - explicit conservation action. We close with a
discussion on applying dynamic conservation planning in response to future climate change.
7.4.1 Incorporating d ynamic b iotic and
a biotic p rocesses into c onservation p lans
The distribution of the conservation features that we
are trying to conserve, usually species or habitat types,
will change over time (Box 7.4 ). Dedicating a site as a
reserve may affect the likelihood of losing a conservation feature from an area, or affect the time period over
which the loss takes place. Species ’ distributions, in
particular, can change rapidly, often in response to
predictable threats. Some of this change is associated
with human - induced threats, such as an invasive
species, habitat modifi cation, or anthropogenic climate
change, while other changes are ‘ natural ’ . The fi rst
question that we therefore need to consider is the
extent to which reserves can stop change, ameliorate
it, or do next to nothing to infl uence a changing
distribution.
Where a reserve does not ameliorate a threat, such
as a fl ood or a hurricane, then conservation planning
needs to consider two things: fi rst, how to set priorities
that preferentially conserve sites with low levels of
threat; and second, how much risk - spreading is necessary to provide adequate persistence in the face of that
threat (e.g. how many separate sites might be required
uncertainties involved to predict the rate and magnitude of extinctions in the 21st century accurately.
What we can say is that, despite the variation in performance of efforts to model climate - driven shifts in
species ’ geographical ranges, enormous changes in
species ’ distributions seem inevitable given substantial
climate change. While many biologists would probably
subscribe to this view, it is much less clear what actions
we can take to avert, or at least minimize, these future
extinctions as a result of climate change.
7.4 WHAT DO WE DO ABOUT IT?
DYNAMIC CONSERVATION PLANNING
Long - term ecology tells us that species ’ distributions
are highly dynamic, and our conservation response to
continuing human threats must be similarly dynamic
if it is to succeed. Biogeographers and ecologists have
already begun to use insights derived from past
changes, together with new statistical techniques, to
build predictions about the future changing patterns of
biodiversity. We have already argued that almost every
aspect of the conservation planning problem is
dynamic and that static conservation planning has its
limitations.
The question remains, what should we do about
this? The theory, and practice, of conservation planning in a dynamic world is in its infancy compared to
static conservation planning. It would nonetheless be
a hard task to cover every dynamic aspect of conservation planning, so here we introduce a few problems and
the ways they can be tackled. In its broadest sense,
dynamic conservation planning is about taking any
1 whether the distributional models capture the mechanisms controlling distribution;
2 assumptions made about the dispersal powers of the species;
3 a lack of consideration of the role of ecological interactions with other species;
4 huge uncertainty about the climate change models used in projecting the future distributions;
5 assumptions about how area losses might translate into overall numbers of species losses (Thuiller
et al. , 2004 ; Whittaker et al. , 2005 ; Ladle, 2009 ).
In respect of the last of these, see the further discussion of the use of the canonical species – area
value of z = 0.25 in projections of regional species losses in Section 8.2.1 .
Taking account of all of these sources of uncertainty, it quickly becomes apparent that the quantitative projections of losses provided by this study, although originally presented as a range of
values and subsequently widely cited in scientifi c, policy and popular discourse, are misleadingly
precise values that should be regarded as a conjecture rather than a forecast or prediction (Ladle
et al. , 2005 ).