Landscape planning for biodiversity conservation in agricultural regions: A case study from the Wheatbelt of Western Australia
Biodiversity Technical Paper, No. 2
Robert J. Lambeck, CSIRO Division of Wildlife and Ecology
Commonwealth of Australia, 1999
ISBN 0 6422 1423 9
Chapter 3 - Integrating biodiversity conservation with other land uses (continued)
When making decisions about what land uses are to be allocated to which portions of a landscape it is important to be clear about the basis for those decisions. This is particularly the case where there are a number of stakeholder groups involved in the planning exercise. By formalising the 'rules' whereby decisions are made and by making those rules transparent, all parties are aware of how decisions are being made and how outcomes are arrived at. The term 'guidelines' is used in a LUPIS exercise, rather than 'rules' to reflect the fact that they are simply recommendations and that their relative importance can be changed.
Three types of guidelines are used in an allocation exercise. These are termed commitment, exclusion and preference guidelines. Commitment guidelines are used where there is a consensus among all stakeholders that a particular land unit can be used for one use only. For example, in the Wallatin Catchment, all participants agreed that there should be no further clearing of remnant vegetation. This objective was captured in a commitment guideline which stated that all existing remnants be committed to remain as remnants. Exclusion guidelines, as the name implies, exclude specified land uses from particular land units but allow other suitable uses. Preference guidelines allow any suitable land use to be applied to specified land units with the decision as to which use is allocated being determined by the relative weighting applied to each guideline.
The procedure adopted in a LUPIS exercise does not require the participants to agree about the content of those rules before the exercise commences. Each stakeholder group or individual can submit their own guidelines. The allocation process is then used to explore the implications of implementing the different guidelines or of altering their relative importance.
The land uses that were identified by the various stakeholders are as follows:
- remnant vegetation protection
- heath revegetation
- Wandoo woodland revegetation
- Mallee revegetation
- Salmon gum/gimlet revegetation
- York gum/Jam wattle revegetation
- Jam wattle/York gum revegetation
- Banksia woodland revegetation
- alleys with lupin/cereal rotation
- alleys with pasture/cereal rotation
- alleys with pasture/pasture/cereal rotation
- alleys with pulses/cereals rotation
- pasture/cereals rotation with perennials around recharge features
- pulses/cereals/canola/cereals rotation with perennials around recharge features
- pulses/cereals/canola/cereals/pasture rotation with perennials around recharge features
- pulses/cereals/cereals rotation with perennials around recharge features.
The guidelines identified by the different stakeholders were then used to allocate each of the land uses to different land units. The following statements illustrate the structure of the guidelines used for allocating the land uses:
- Commit all vegetation remnants (public or private) to remnant vegetation protection.
Only one commitment guideline was deemed necessary for the issues being considered. This is a nature conservation guideline which reflects the consensus among stakeholders that all remaining patches should be retained.
The following guidelines reflect the preferred land use options as perceived by different stakeholders. The guidelines presented here are simply examples to provide a flavour of the type of guidelines used. The full list of preference guidelines used in the Wallatin case study is presented in Appendix 5.
- Allocate landform Merredin to revegetation with Salmon gum/Gimlet woodland.
- Allocate areas < 20 ha on gutless sands to revegetation with Banksia woodland.
- Allocate Gravelly uplands to alleys of deep rooted perennials interspersed with lupin/cereal rotation.
- Allocate Salmon gum/Gimlet soils to a pasture/cereal rotation with perennials around recharge features.
The first two of these guidelines are designed to address nature conservation objectives while the second two simultaneously address production and hydrological goals.
No exclusion guidelines were considered necessary for the current exercise. In some exercises a potential exclusion guideline may take the form: 'Exclude grazing from all remnant vegetation'. This was not necessary in the current exercise as the commitment guideline to retain remnant vegetation as remnants effectively precluded this option.
Having identified the stakeholders, determined the relevant issues, nominated the land uses appropriate for addressing those issues, assessed the suitability of the landscape for those uses and developed guidelines for allocating land uses to different parts of the landscape, the next phase is to embark on the allocation process.
The guidelines identified in the previous section are converted to computer code and incorporated into LUPIS. Weightings which reflect the social preferences of the stake-holders are then attached to each of the guidelines. On the basis of these weightings LUPIS calculates the relative suitability of each land unit for each land use and allocates each unit to the use with the highest suitability score (Ive 1992).
An important feature of the weighting procedure is that it reflects social preferences rather than relying on a common 'currency' that can be compared across all objectives. If such a currency could be developed it could be used in a LUPIS exercise. However, there is considerable scepticism among many stakeholders about attempts to express non-monetary values, such as amenity and conservation, in dollar equivalents. In a LUPIS exercise the performance of each guideline is assessed against the objectives that the guideline was formulated to address. For example, the performance of conservation guidelines is assessed by the capacity of the solution to deliver a specified conservation outcome. Similarly, the performance of hydrological guidelines is judged according to the extent to which the allocation resolves a hydrological problem. Valuing the different land uses in a common currency (inevitably dollars) and comparing the relative performance of each guideline is meaningless if it is unable to assess performance against stated objectives.
Because there is no common currency by which different objectives can be meaningfully compared, it is not possible to specify the relative values that should be attributed to each guideline. For example it is not possible to specify a priori whether a hydrological guideline should have a higher, lower or intermediate weighting than a production or conservation guideline. As stated above, our interest in a LUPIS exercise is to assess the performance of each guideline against the objectives that the guideline is designed to address. LUPIS therefore allows the initial weightings to be set arbitrarily. A convenient starting point is to assume that all guidelines are equally important and to give them all an equivalent weighting. An interim land-use plan is generated and is assessed against the different objectives identified by the various stakeholders. If the initial 'solution' is considered not to be performing adequately for any objective, the weightings on the guidelines which address that objective can be increased and the exercise re-run. The process is therefore an iterative one with subsequent plans converging towards a solution that is acceptable to all stakeholders.
Figure 17 represents the distribution of different land uses in the Wallatin Creek Catchment following an initial allocation based on equal weights for all guidelines. The proportion of the landscape allocated to each land use when guidelines are equally weighted is displayed in Figure 18. For presentation purposes land uses were combined into the following broad categories:
- remnant vegetation protection
- revegetation for nature conservation
- continuous cropping in alleys
- pasture/cropping rotation in alleys
- continuous cropping with strategic perennial plantings
- pasture/cropping rotation with strategic perennial plantings.
While Figures 17 and 18 indicate how much land has been allocated to each land use it does not tell us how well any particular guideline is performing relative to its potential. In other words it doesn't tell us how much of the land that is suitable for a particular use has actually been allocated to that use. Figure 19 represents an extract from a LUPIS output which indicates the proportion of suitable land that has actually been allocated to the use specified in each guideline. It provides an assessment of the extent to which the various guidelines have been satisfied. Because different guidelines may represent the interests of different stakeholder groups it is possible for all stakeholders to assess how well their interests are being addressed.
A change in the performance of any one guideline as a result of changing its weighting will result in a change in the performance of one or more other guidelines. Consequently it is possible to assess the impact on all objectives of changing the weightings on guidelines pertaining to a particular objective. It is therefore possible to quantify the likely impact on production of addressing nature conservation and hydrology objectives. Such assessments are based on the assumption that productivity for any specified land use is equivalent on equivalent soil types throughout the catchment.
Figure 22: Preferred land uses solution with additional conservation commitment in which all 'non-viable' patches are enhanced to meet minimum size requirements and additional areas are allocated to salmon gum/gimlet reconstruction in recognition of the under-representation of this patch type in the catchment.
Figures 20 – 22 show the results of three different nature conservation scenarios. Figure 20 represents a solution where conservation is limited to the protection of existing remnants. This was achieved by applying a rating of zero to all conservation guidelines.
In Figure 21 the weightings were increased on guidelines for re-establishing habitat adjacent to patches that failed to meet the minimum size requirements identified in Chapter 2. This solution increased the area allocated to nature conservation by 4.2% which, when added to the existing remnants, accounts for 11.6% of the catchment.
Figure 22 represents the results of an allocation exercise with an additional emphasis on conservation enhancement aimed at increasing the area of salmon gum/gimlet woodland. This patch type is considered to be under-represented in the area. This particular solution requires an additional 6% of the catchment. Changes to the proportion of the catchment allocated to other land uses in response to these changes can be seen in Figure 23.