Site significance provides the values context for comparing a site with similar or related sites. This can help establish priorities in managing geoconservation values. Eight specific types of significance are recognised, with the following definitions:
- Outstanding reference: the site is an exceptionally unambiguous example or demonstration of an aspect of geodiversity.
- Representative reference: the site is a clear example of the typical expression of an aspect of geodiversity. Representative reference sites should be selected with consideration of i) how well they typify an aspect of geodiversity, ii) condition, iii) security and iv) appropriate accessibility.
- Key site: the site displays or demonstrates a feature, event or process that is fundamental to understanding an aspect of geodiversity within a specified context area. This includes but is not limited to formally defined type sections and localities.
- Well studied: the site has been the subject of considerable geoscientific investigation, providing data and analysis valuable to the understanding of an aspect of geodiversity.
- Minimally impacted condition: the site is one of the least disturbed examples of an aspect of geodiversity.
- Rarity: the site constitutes a significant proportion of all sites representing a particular aspect of geodiversity within a given context area. If the site were to be destroyed or degraded then much of the entire population would be lost.
- Outlier: the site is marginal to or isolated from similar features, in either space or time or both. It therefore provides additional information about the range of an aspect of geodiversity, its process of formation or the prior distribution of a formerly more extensive entity or process.
- Information Repository: the site contains or is likely to embody detailed information that has significantly improved, or has the potential to improve, understanding of an aspect of geodiversity within a specified context area.
The above significance types have been identified for sites listed since 2017 and will be applied to earlier listings upon review, as time and resources permit.
Four levels of significance are recognised: District, State, National and Global, with the appropriate level being the highest at which the definition of significance type remains demonstrably true or relevant. The level of site significance can only be determined or modified by a quorum of the TGD Reference Group.
An example of a feature that is rare in Tasmania but common elsewhere would be considered significant at State level. If that feature was rare outside Tasmania, or occurred only in Tasmania, then it might be considered significant at National or Global levels.
Geoconservation values of a site may be affected by human actions. Potential threats to site integrity are classed by both mechanism and scale, with the broad categories being:
- Ground disturbance – four levels
- Collection – two levels
- Concealment – two types
- Vegetation disturbance – three types / levels
- Fire – two levels
- Catchment effects – three types
- Climate change
Sites are tagged
either ‘yes’ or ‘no’ in regard to their sensitivity to each of these potential
threats. This provides an initial guide
for assessing whether or not an activity has potential to damage the
geoconservation values of a site. This does
not take account of possible variations in sensitivity across it, as in the
case of large sites where sensitive component features are not uniformly
distributed across the listed area. Ideally, sensitivity should be assessed on
a case-by-case basis in the context of specific developments.
Additional information, including detail
definitions of each of the potential threats, is available on the Geodiversity
tab of the Natural Values Atlas.
Proposals to add, delete or amend sites are assessed at annual meetings of the Tasmanian Geoconservation Database Reference Group. The group brings together expertise in the earth sciences from staff at the University of Tasmania, government departments and independent consultants. Criteria for listing are specified in the Terms of Reference.
- Proposed site - sites submitted to the Tasmanian Geoconservation Database Reference Group, prior to being formally considered by that group. These sites are not included in published versions of the database.
- Site under consideration - site tabled at the Tasmanian Geoconservation Database Reference Group, where the group determines that the site potentially satisfies the criteria for listing but requires more information before accepting it for listing in full. Sites under consideration are included in published versions of the TGD.
- Listed sites - sites accepted for listing by the TGD Reference Group.
Any person can nominate a site or propose an amendment. Nominations are referred to TGDRG, which
advises DPIPWE whether or not the proposal is supported on scientific grounds.
The expert panel may suggest changes to the nomination to ensure that it satisfies
the listing criteria and TGD documentation standards. To assist compilation of a site nomination or
proposed amendment help documents are available on the Geodiversity tab of the Natural Values Atlas or see contact below.