The Commonwealth proposed the following broad reservation principles for the inclusion of individual elements of biodiversity:
With time and data limitations it was considered impractical to attempt to include all forest species in the IAP. Priority was therefore given to individual species that are:
The inclusion of rare or threatened species in the assessment involved the following steps:
Expert panels were established to identify priority species for inclusion and to determine species-specific reservation targets using guidelines supplied by the CWG. Due to time constraints only those species of the highest priority were considered in the IAP. For each selected fauna species, the panels modified existing models of predicted habitat or developed expert models based upon known habitat requirements. For each flora species, the panels reviewed data on localities and population sizes.
The process for identifying species reservation targets was based upon taking into account a species' population structure, regional vulnerability and its national distribution to identify viable population units (fauna) or number of localities (flora) as a basis for reservation.
There is a need to reserve species across their geographic range in order to allow for the conservation of genetic diversity and, through continued gene flow, the maintenance of metapopulations within and beyond each study area. This is achieved, where required, by identifying species-specific sub-regions within each region. The expert panels examined each species distribution against identified dispersal barriers, known genetic variation and broad environmental gradients to identify sub-regions for all species under consideration.
Four expert panels were established by the CWG. One flora and one fauna panel were established for each of the study areas north and south of Sydney. Each panel comprised:
The panels were directed to perform the following tasks:
The flora panels considered all plant species which were:
From these, the panels identified priority lists of species for each IAP negotiation area (refer Figure 2.2) as sub-sets of Schedule 1 & 2 species in that area, except for the three southern negotiation areas (S1, S2 and Eden) which were considered concurrently. A specific IAP threatened species plant data base was constructed for the above areas, using: existing herbarium records, records from a range of flora surveys ( including the NEFBS and NRAC data bases for the north), and additional reliable records from recent surveys, literature and expert knowledge. All available and additional data was screened as exhaustively as possible for all taxa considered by the panels. Given limitations, only data for endangered and vulnerable species were comprehensively checked. The panels reviewed all records to establish data bases for the IAP which conformed to minimum data quality standards, such that:
Baseline reservation targets were set for the following threat categories:
For each target species, the panels then considered adjusting the targets (up or down from the baseline) depending on the level of endemism, life history and threats to their habitat. Where sub-regions were identified for species, the panels set targets for each sub-region. The panels also identified irreplaceable localities for reservation where these supported major populations (ie. many individuals relative to other localities) or where these included high quality (eg. undisturbed) habitat relative to other localities. Proformas were completed for all endangered and vulnerable species where base targets were adjusted by the expert panel.
The lists of flora species used in the IAP and the reservation targets set is included in Appendix 4 of the Project report.
The fauna panels considered all animal species which were:
From these, the panels identified priority lists of species for each region. The panels reviewed records to establish data bases for the IAP and either reviewed models predicting the occurrence of species across the landscape or developed expert models based on species' known habitat preferences. For expert models, habitat for a species was derived using rules formulated by the expert panels incorporating predictive models developed by NPWS, known records and expert knowledge of known associations of species with forest type and growth stage.
The northern panel identified three classes of habitat and weighted them within each expert model to reflect the perceived quality of predicted habitat and to ensure that the best habitat was always given priority in attempting to meet reservation targets. The southern fauna panel identified the habitat categories that reflected the best habitat (Habitat Class 1) after viewing the predictive model outputs. Only Class 1 habitat was considered in the southern assessment as the panel were not confident about setting weights for lower classes.
The predictive models generated by the Panels were based on mapped variables (eg. temperature, rainfall, geology etc) and enabled extrapolation of likely suitable habitat elsewhere in a region from known localities. The same procedure was used in the north and south, although pre-existing quantitative models were available for the north from the North East Forest Biodiversity Study (NPWS 1995).
Specific biological principles were used to develop a procedure for determining reservation targets for fauna:
Within this framework, expert knowledge was used in combination with the best available predictive model (eg quantitative habitat models developed by NPWS for NE NSW) and locality information to establish the area required to maintain viable population units. In this way, source populations of species vulnerable to threatening processes were targetted for protection throughout the forest estate.
The fauna panels determined reservation targets for priority fauna species by:
Expert models identified the habitat features necessary to maintain viable populations for each species under consideration. The small fragments of isolated habitat were assessed as likely to be ineffective in maintaining viable populations. Small areas also pose a problem within the conservation planning software system (refer Section 2.5), as a small, fragmented occurrence of predicted habitat conferred high irreplacibility on a compartment. This problem was particularly acute for space-demanding fauna species, such as owls and gliders which require extensive tracts of habitat in order to maintain viable populations.
Predicted habitat for space demanding species was therefore 'filtered' to ensure that only consolidated blocks of suitable habitat were considered by the conservation planning software in meeting targets. The filtering process was accomplished using pre-processing within Win ERMS. A square consisting of twice the breeding unit home range of the species being examined was centred on each grid cell mapped as containing viable habitat. The grid cell under examination was then only retained by the filter if more than 30% of cells within this square also contained viable habitat. In this way, all isolated habitat fragments were removed from the model. The filtering process therefore resulted in reductions to the total area of suitable habitat considered for deferral.
A list of fauna species used in the IAP and the reservation targets set are included in Appendix 5 of the Project report. The Project report also contains information on data limitations, compliance with Commonwealth reserve criteria and indicates priority areas for further work during the CRA process.