5.1 Geological and geomorphological and soil values
The identification and assessment of sites of indicative national estate geoheritage significance in the lower north east comprehensive regional assessment forest region was undertaken as part of a state-wide assessment by Osborne et al (1998).
Areas that may be identified as having geoheritage value (National Estate Criteria A.1, A.2, A.3, B.1, C.1 and D.1) include places important:
in the evolution of Australian landscapes or climate (A.1);
in maintaining existing processes or natural systems at the regional or national scale (A.2);
in exhibiting unusual richness or diversity of landscapes (A.3);
for rare, endangered or uncommon natural landscapes or
for information contributing to a wider understanding of Australian natural history by virtue of its use as a research site, teaching site, type locality, reference or benchmark site (C.1);
in demonstrating the principal characteristics of the range of landscapes, environments or ecosystems, the attributes of which identify them as being characteristic of their class (D.1).
The methodology being undertaken for the project includes:
the development and application of thresholds for national estate assessment purposes based on a review of the significance of the identified sites;
documentation of potential national estate geoheritage sites;
sensitivity analysis of all potential national estate geoheritage sites; and
development of conservation management guidelines for those sites identified
The consultant assessed scientific journals and other published material for place-related information that was likely to identify potential places of geoheritage significance. Published geological maps and topographic maps were examined and potential features of geological significance identified. Other sources of data included contact with various institutions, and contact with numerous experts.
5.1.2 Establishing the threshold
Potential places were listed against the relevant national estate criteria identified in regional reviews undertaken by the consultant. Places were classified into three groups depending on the quality of data on values and location:-
1 - The values and location of the place can be determined from the available data.
2 - There is insufficient data available at this time to the values at the place.
3 - There is insufficient data available as to the location of the place.
The consultant has recommended that because of limitations in the data, including poorly defined locality information and a lack of ground truthing, that it would not be appropriate to threshold the sites. Accordingly, the data will be used as an informing–type layer which can be used to enhance documentation of national estate places identified from other assessments, and as a contextual layer for reserve design.
A lack of suitable data did not mean that these places lack significance or that with more detailed literature or field investigation, that their status could not be satisfactorily established in the future. However, it was not possible to undertake this further work within the constraints of the CRA assessments.
Of the sites where spatial information was available, 120 Geoheritage sites (unthresholded) were delineated for the lower north east CRA region, 35 occurring in National Parks, 12 in State Forests, 64 on private land, 7 on vacant crown land, and 2 on leasehold land (See Appendix H). There were some additional sites identified where spatial information was not available. The areas identified as a result of this process are yet to be delineated spatially.
The conservation management guidelines were limited to a ‘fragility’ ranking. A four step scale was applied to each place, where spatial information was available, corresponding to the extreme ends of the scale used by Dixon et al (1997) to classify sensitivity of sites identified, 1 being highly sensitive to 4 being highly robust for each place report.
5.2 Natural history values
The identification and assessment of sites of indicative national estate natural history significance in the UNE comprehensive regional assessment forest region was undertaken as part of a state-wide assessment by Denny (1998).
Areas which may be identified as having natural history value (National Estate Criteria C.1) include places important ‘…for information to contributing to the wider understanding of Australian natural history, by virtue of its use as a research site, teaching site, type locality, reference or benchmark site’.
Data sources included literature searches of established journals, conference proceedings, contact with various institutions including natural history societies, and contact with numerous experts. The consultant assessed the national estate values of identified places against the national estate criteria by ranking the importance of each site, in terms of its contribution to Australian Natural History. The sites were ranked as having high, moderate or low value as a C1 site of national estate importance.
5.2.2 Establishing the threshold
Various factors were used to derive threshold values for each site type including such elements as the rigour of methodology, accuracy of location, the availability of information and overall reliability of the data sources used. By applying the elements described above, the consultant ranked each site as having high, moderate or low value as a C1 site of national estate importance. On this basis, it was recommended that rejected sites, ie those with a low ranking, were not included in the assessment.
79 Natural History sites (unthresholded) were delineated for the lower north east CRA region, 24 occurring in National Parks, 10 in State Forests, 43 on private land, and 2 on vacant crown land. 52 of the 79 sites indicated above were identified as being above threshold (See Appendix I). The areas identified as a result of this process are yet to be delineated spatially.