1. Introduction

1.1. CONTEXT AND AIMS

This document has been prepared by the NPWS for the purpose of the NSW eastern forests Comprehensive Regional Assessments (CRAs). The document is set within the CRA context, which include:

• adoption of reserve criteria as outlined by The Joint ANZECC/MCFFA National Forest Policy Statement Implementation Sub-committee (JANIS) report,
  
• agreements on the application of the above (for example, the type and number of criteria and entities to be considered),
  
• agreement on the areal reservation targets and weights assigned to individual entities
  
• the context of the landscape under consideration being forest ecosystems in eastern NSW.

This paper deals only with issues relating to the spatial design or configuration of reserves. It does not address selection issues relating to which entities (or how much of each entity) should be included in reserves, nor issues relating to the type of protection (e.g. formal versus informal reservation) to be afforded to different parts of the reserve system. These issues are being addressed elsewhere in the CRA process. The paper attempts to discuss spatial design criteria against a background of the scientific literature and the resultant debates. Although relevant to the establishment of a CAR reserve system, the reserve design criteria outlined in JANIS for implementation in the CRA planning process, are at times overlapping. As such, all relevant JANIS criteria will be dealt with under the broad design principles of shape, size, connectivity and replication. Hence, the specific aims of this discussion paper are to:

1. Highlight JANIS criteria relating to reserve design (or spatial configuration) principles,
   
2. Provide a literature review based on core reserve design principles; size, shape, connectivity and replication.
   
3. Highlight existing spatial configuration tools or mechanisms being employed in the CRAs.
   
4. Provide, where needed, recommendations on how reserve design principles should be further addressed in the CRA process.

1.2. JANIS CRITERIA RELATING TO SPATIAL DESIGN AND CONFIGURATION OF RESERVES

This section identifies those elements of JANIS that specifically relate to spatial design and configuration of reserves. JANIS specifies spatial configuration criteria for entities as well as reserve design in general. There are many reserve design issues raised in these sections of JANIS that need to be addressed in the scope of this paper. No one issue stands alone—they are all intertwined, influence each other and are at times conflicting. As such, these issues will be addressed under the broad design sections mentioned above.

1.2.1. JANIS sections relating to entities

SECTION 3.2

Adequacy relates to the maintenance of ecological viability and integrity of populations, species and communities (NFPS, 1992).

SECTION 6.1 - Discussion, 6.1.1

The Convention on Biological Diversity and the National Strategy for the Conservation of Australia’s Biological Diversity consider biodiversity at three levels: genetic, species and ecosystem. While there is considerable information on the spatial patterning of biodiversity at the ecosystem and species levels, the information on genetic variation is limited. Although, it is possible and desirable to use this limited genetic information in planning a reserve network, the biodiversity criteria outlined (see Section 6.1.2) relate primarily to biodiversity at the forest ecosystem and species levels.

SECTION 6.1 - Biodiversity criteria, 6.1.2, point (4)

Reserved areas should be replicated across the geographic range of the forest ecosystem to decrease the likelihood that chance events such as wildfire or disease will cause the forest ecosystem to decline.

SECTION 6.1 - Biodiversity criteria, 6.1.2, point (6)

Reserves should be large enough to sustain the viability, quality and integrity of populations.

SECTION 6.1 - Biodiversity criteria, 6.1.2, point (7)

To ensure representativeness, the reserve system should, as far as possible, sample the full range of biological variation within each forest ecosystem, by sampling the range of environmental variation typical of its geographic range and sampling its range of successional stages.

SECTION 6.2 - Old-growth forest criteria, 6.2.2, point (2)

- the representation of old-growth forest across the geographic range of the forest ecosystem;

- appropriate reserve design;

- protection of the largest and least fragmented areas of old growth.

1.2.2. JANIS section relating to general reserve design and configuration

SECTION 7 - Reserve design and management

- boundaries should be set in a landscape context with strong ecological integrity, such as catchments;

- large reserved areas are preferable to small reserved areas, though a range of reserve sizes may be appropriate to adequately sample conservation values;

- boundary-area ratios should be minimised and linear reserves should be avoided where possible except for riverine systems and corridors identified as having significant value for nature conservation;

- reserves should be developed across the major environmental gradients if feasible, but only if these gradients incorporate key conservation attributes which should be incorporated in the CAR system;

- each reserve should contribute to satisfying as many reserve criteria as possible;

- reserve design should aim to minimise the impact of threatening processes, particularly from adjoining areas;

- reserves should be linked through a variety of mechanisms, wherever practicable, across the landscape.

1.2.3. Reserve design and selection principles

Reserve design principles are those size, shape and configuration decisions which are made in order to finalise the placement of the boundaries of a conservation mechanism (in this case a reserve or reserve network). The decisions are primarily made to enhance the adequacy of the reserve or reserve network for protecting the target entity or feature. However, practitioners also apply these principles to:

• ensure appropriate protection of cultural heritage (both indigenous and non-indigenous)
  
• to incorporate other features such as scenic or recreational features
  
• the use of a cadastral feature for ease of legal definition and management of a reserve, and
  
• to incorporate access to allow for management of an area

There are two distinct aspects to conservation evaluation, reserve design and reserve selection. Before reserves can be designed to ensure their adequacy, those areas that are the most important to preserve must be identified and selected for conservation. Reserve selection usually involves systematic ranking and scoring procedures to effectively choose sites that contain the targeted features for incorporation into nature reserves, thus increasing the potential of the reserve system to efficiently conserve biodiversity (Pressey, 1990). Historically, much emphasis has been placed on reserve design principles (Slatyer, 1975; Noss, 1983; Soule and Simberloff, 1986; Noss, 1987; Scott et al., 1989; Simberloff, 1994). These are based on ecological theories that seek to gain a better understanding of ecosystem structure, how species are distributed across the landscape in space and time, and how to apply these concepts to formulate conservation policy and to design adequate nature reserves. The many recommendations for the best size, shape, and connectivity across the region with respect to position in a patchwork of often urban, rural and natural land have been adopted by applied ecologists and reserve design planners. Mechanisms and guidelines for the application (i.e. ‘operationalising’ the JANIS criteria) are needed for the CRA process.

1.3. SPATIAL CONFIGURATION FUNCTIONALITY WITHIN C-PLAN

The C-Plan software package being used to select reserves in NSW CRAs has recently been extended to incorporate automated derivation of indices relating to two attributes of reserve configuration:

• patch size and connectivity; and
  
• geographical and environmental spread.

Each of these attributes can be measured in relation to any specified entity (e.g. species, forest ecosystem) or set of entities. The attributes can be considered at two different points within CPlan. When reporting on progressive achievement of areal targets the software can now also report on progressive achievement of spatial configuration goals for reservation of specified entities. For patch size/connectivity this is reported in terms of an index reflecting the size and connectivity of reserved patches of a given entity. For geographical/environmental spread this is reported in terms of an index measuring the extent to which reserved areas of an entity are spread across the geographical and environmental range of the entity.

C-Plan can also consider spatial configuration when estimating the potential contribution that currently unreserved planning units would make to the reserve system. ‘Irreplaceability’ indices can now be automatically adjusted (weighted) to reflect not only the contribution that a planning unit would make to achieving areal targets but also the contribution to achieving spatial configuration goals in terms of patch size/connectivity and geographical/environmental spread.

All of the new functionality is designed to run in ‘real time’ during selection of reserves. In other words, the indices can be calculated fast enough (in seconds rather than minutes or hours) to facilitate iterative recalculation whenever a change is made to the configuration of the reserve system.

The new C-Plan functionality is being documented in detail in a separate CRA report. The functionality is referred to in the following sections of this paper wherever it is deemed relevant to the design criteria discussed.

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