570 likes | 785 Views
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?.
E N D
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.
Poor planning may also increase conflict with neighbouring communities by failing to allow for animal migration routes.
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: • The PA systems tend to conserve areas that are favoured by one or two key people and lack general support. • They fail to set explicit targets and are easily derailed by lobbying from political or economic pressure groups. • 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 feature-site 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. Score = (1.5 * Species No.) + (2.4 * Endemic species No.)
1) Scoring systems Advantages of scoring systems: • They are simple to develop and adapt. • They do not rely on complicated computer software. • They do not rely on complete coverage to identify important areas (eg IBAs).
1) Scoring systems Disadvantages of scoring systems: • The areas they select are inefficient in representing biodiversity. • 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 A B C D E F Area 2 A C I J K Area 3 A B M N Area 4 A X
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: • Identifying the planning region and dividing it into a number of planning units. • Listing the abundance of each conservation feature in each planning unit. • Setting representation targets for each conservation feature. • Assigning a cost value for each planning unit. • Measuring the effectiveness of the present PA system. • 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
A preliminary conservation planning exercise for Maputaland, South Africa.
A preliminary conservation planning exercise for Maputaland, South Africa.
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