Transcript 1) Scoring systems

An introduction to systematic
conservation planning
Bob Smith
• Why do we need conservation land-use planning?
• How have conservation networks been developed
in the past?
• What is systematic conservation planning?
• How should new areas be selected?
In this workshop I will use protected area (PA) as shorthand
for areas that are established to conserve their biodiversity.
However, a conservation land-use plan could include
privately- and community-owned land, as well as formal PAs
managed by the government.
Land-use plans would also generally include designating
land for the sustainable use of natural resources and
biodiversity-friendly agricultural practices. This may be
especially relevant for CWRs.
PAs have often been designated in areas of high
scenic value or in wilderness areas.
They are also often located in the “land that
nobody wanted”.
These areas tend to have low biodiversity value
and are at lower risk of being affected by land
transformation or over-harvesting.
Most national protected area (PA) systems fail to
represent their biodiversity and many PAs will fail
to conserve the biodiversity that they contain.
1400 100
Percentage protected
1200
80
1000
800
600
400
60
40
20
200
Elevation
600+
NNR
AreaSSSI
(km2) Unprotected
10+
0.5 - 1
0.1 - 0.5
201-400 401-600
0.05 - 0.1
0.01 - 0.05
0-200
1 - 10
0
0 - 0.01
0
n
a
nzania
Ethiopia
Kenya
Poor planning may also
increase conflict with
neighbouring
communities by failing to
Somalia
allow for animal migration
routes.
Tsavo National
Park
Indian
Ocean
Based on this, it is now widely recognised that much of
global biodiversity is threatened with extinction and so
methods are needed to improve the conservation value of
global PA systems.
Experts working in an area often have a great deal of
knowledge about the biodiversity of a region and
supplementing this with data collected in the field can be
expensive. For these reasons, it is common for a small group
of experts to decide where to place PAs by drawing lines on
maps.
Unfortunately, this has the following problems:
1. The PA systems tend to conserve areas that are favoured
by one or two key people and lack general support.
2. They fail to set explicit targets and are easily derailed by
lobbying from political or economic pressure groups.
3. It is difficult for people to incorporate a wide range of
biodiversity and socio-economic data and so these
exercises tend to focus on conserving a small number of
biodiversity elements.
“A distinct advantage of the expert-driven approach is its incorporation of
expert knowledge on biodiversity persistence and pragmatic management
and implementation issues not normally included in biodiversity featuresite data matrices.”
“Overall, the wishlist reflected a desire by managers to improve
management efficiency and facilitate rapid implementation by expanding
existing, largely montane reserves into low-priority areas where land
tenure is sympathetic to conservation. Consequently, it was not very
effective and efficient in achieving pattern and process targets, and it
excluded large areas of vulnerable and inadequately conserved lowland
habitat - the areas currently in most need of conservation action.”
Cowling et al 2003 Biological Conservation 112, 147-167
Three main systems have developed to identify where new
PAs should be located or where existing PAs should be
modified. These are based on the following concepts:
1) Combinatorial scoring systems (hotspots)
2) Complementarity
3) Irreplaceability
Issues of viability and implementability are also important.
1) Scoring systems
Rigorous scoring systems have been developed based on data
collected on the biodiversity value of an area. Such systems
also often included data on a range of physical, aesthetic,
cultural and socio-economic factors.
87 species
24 endemic species
35 threatened species
112 species
31 endemic species
46 threatened species
Score = (1.5 * Species No.) + (2.4 * Endemic species No.)
1) Scoring systems
1) Scoring systems
1) Scoring systems
Advantages of scoring systems:
A. They are simple to develop and adapt.
B. They do not rely on complicated computer software.
C. They do not rely on complete coverage to identify
important areas (eg IBAs).
1) Scoring systems
Disadvantages of scoring systems:
A. The areas they select are inefficient in representing
biodiversity.
B. They fail to set explicit targets for each conservation
feature, so might not effectively conserve the focal
biodiversity elements.
1) Scoring systems
Disadvantages of scoring systems:
A) Inefficient
This is a significant problem as has been amply illustrated in
the conservation planning literature.
An example of a reserve selection exercise:
Area 1
Area 2
Area 3
Area 4
An example of a reserve selection exercise:
Area 1
Area 2
Area 3
Area 4
An example of a reserve selection exercise:
Area 1
Area 2
Area 3
Area 4
An example of a reserve selection exercise:
Area 1
Area 2
Area 3
Area 4
1) Scoring systems
WORLDMAP demonstration:
1) Scoring systems
Disadvantages of scoring systems:
B) Fail to set explicit targets
The number of high-scoring sites that are conserved is rarely
set to ensure the long-term persistence of the focal taxa. This
means that political or economic factors may influence which
sites are selected and the final system may be ineffective.
1) Scoring systems
Despite these problems, hotspots are still frequently used.
The most well known of these is Conservation International’s
hotspots.
1) Scoring systems
This is because inefficiency is less of a problem when there is
little overlap in the elements found at the different sites.
Area 1
Area 2
Area 3
Area 4
A
A
A
A
B
C
B
X
C
I
M
D
J
N
E
K
F
1) Scoring systems
A scoring system approach is also the basis of Key
Biodiversity Areas, which select areas based on
the presence of:
• Globally threatened species
• Restricted range species
• Congregatory species
• Biome restricted assemblages
1) Scoring systems
Advantages of KBAs
•
They do not require distribution maps for the whole
planning region
•
They do not require an existing conservation
planning system
•
They identify manageable sites
1) Scoring systems
Disadvantages of KBAs
•
They are inefficient
•
They miss some species, eg wide-ranging
•
They do not allow for existing levels of protection
•
No flexibility
•
They do not allow other factors to be included
Great first step to identify “jewels in the crown”
Area 1
Area 2
Area 3
Area 4
1) Scoring systems
However finer-scale planning systems based entirely on
scoring systems can be problematic…
1) Scoring systems
The scoring system used to identify SPAs for water birds:
Stage 1.1: An area used regularly by 1% of the Great Britain population of any
species listed as rare or vulnerable in Annex I of the Birds Directive (Article 4.1) in
any season (i.e. whooper swan and Bewick's swan).
Stage 1.2: An area used regularly by greater than 1% of the biogeographical
population of those species listed as regularly occurring migratory species (Article
4.2) in any season (i.e. goldeneye and tufted duck).
Stage 1.3: An area used regularly by more than 20,000 waterfowl (waterfowl as
defined by the Ramsar Convention) in any season.
Stage 1.4: To provide an adequate suite of sites for an Annex I or regularly
occurring migratory species where the application of Stage 1.1, 1.2 and 1.3
guidelines for a species does not yield an adequate suite of sites for the
conservation of that species (to target, for example, wider-ranging or thinly
dispersed species).
1) Scoring systems
Jackson et al (2004) Biological Conservation
The percentage of the
national population
occurring within the existing
network of SPAs (open
bars) compared with
population totals for sites
selected using a
complementarity-based
approach for a selection of
the 17 species analysed.
Researchers have responded to these limitations by
developing systematic conservation planning.
This involves a range of techniques but they are all
based on setting explicit representation targets.
Suggested stages in systematic conservation planning
1) Identifying and involving key stakeholders
2) Identifying broad goals for conservation planning
3) Gathering and evaluating data
4) Formulating targets for biodiversity features
5) Reviewing target achievement in existing conservation areas
6) Selecting additional conservation areas
7) Implementing conservation action in selected areas
8) Maintaining and monitoring established conservation areas
Pressey et al. (2003)
The practicalities of running systematic conservation
planning exercises involve:
1. Identifying the planning region and dividing it into a
number of planning units.
2. Listing the abundance of each conservation feature in
each planning unit.
3. Setting representation targets for each conservation
feature.
4. Assigning a cost value for each planning unit.
5. Measuring the effectiveness of the present PA system.
6. Using computer software to identify new planning
units to be incorporated into the system based on
complementarity.
2) Methods based on complementarity
Complementarity is the concept of choosing planning units to
maximise the amount of biodiversity that is protected when
combined.
An example of a reserve selection exercise:
Area 1
Area 2
Area 3
Area 4
An example of a reserve selection exercise:
Area 1
Area 2
Area 3
Area 4
An example of a reserve selection exercise:
Area 1
Area 2
Area 3
Area 4
An example of a reserve selection exercise:
Area 1
Area 2
Area 3
Area 4
An example of a reserve selection exercise:
Area 1
Area 2
Area 3
Area 4
2) Methods based on complementarity
Therefore, methods based on complementarity are
the most efficient at meeting conservation targets
and allow planners to set targets for a whole range
of biodiversity elements.
These targets can be set based on issues of
population or ecological viability, so that PA systems
conserve biodiversity in the long-term.
Many conservation planning articles in the scientific
literature do not use relevant targets and should be
treated with caution.
3) Methods based on irreplaceability
One limitation of methods based on complementarity
is that planning units are identified as either
belonging or not belonging to the final portfolio.
3) Methods based on irreplaceability
Researchers have responded by developing the
concept of irreplaceability. This measures the value of
a planning unit by calculating the extent to which it is
needed to meet the representation targets.
Some units might be
irreplaceable, whereas units
with lower scores could be
swapped with similar, less
contentious units.
Issues of viability and implementability
Portfolios need to conserve viable populations of
each conservation feature.
They also need to include a range of socio-economic
and other data that increases the likelihood that they
will be implemented.
Conservation planning with MARXAN
Developed by researchers at the University of
Queensland. It identifies portfolios that:
• Meet representation targets
• Allow for minimum patch size
• Maximise connectivity
• Minimise cost
• Produce best and irreplaceability score outputs
Ind
ian
Ocea
n
A preliminary conservation planning exercise for
Maputaland, South Africa.
nti
Atla
cO
300 km
n
ce a
Ind
ian
Ocea
n
A preliminary conservation planning exercise for
Maputaland, South Africa.
nti
Atla
cO
300 km
n
ce a
The data came from a 30m
resolution landcover map.
This showed the distribution
of 29 natural landcover types.
The area of each landcover type in a series of 25ha
grid squares was calculated.
Targets were set as:
• 40% of the original extent of endemic and
threatened landcover types
• 20% for the other landcover types
• Whilst maximising connectivity
Preliminary results for Maputaland, RSA
Best solution
Irreplaceability scores
Conservation value
High
Low
Vegetation types
Forest types
Threatened tree species
Threatened vertebrate species
A planning exercise from
Australia shows the value of
including opportunity cost data.
A small increase in
area (<3%) and
boundary length
(<6%), lead to the
economic impact on
the commercial rock
lobster fishery being
reduced by more
than a third.
In conclusion, systematic conservation planning is
more complicated than other schemes but has they
following advantages:
1) It brings people together and builds consensus
2) It identifies information gaps
3) It is transparent
4) It allows success to be measured
5) It is efficient
6) It allows a range of data to be incorporated
7) It acts as a standard framework into which
different schemes can be incorporated