Biodiversity publications archive

Refugia for biological diversity in arid and semi-arid Australia

Biodiversity Series, Paper No. 4
S.R. Morton, J. Short and R.D. Barker, with an Appendix by G.F. Griffin and G. Pearce
Biodiversity Unit
Department of the Environment, Sport and Territories, 1995

16. Management issues

The terms of reference for our investigation ask for consideration of the types and extent of threats to biological diversity in refugia, of the potential to reverse degradation within them, of the possibilities of eliminating threats, and of current land uses and land management. Our approach is first to ask whether the threats to biological diversity within the refugia we have recognised differ in any important ways from those discussed in the wider literature concerning arid Australia. It becomes quickly apparent that such is not the case. The threatening processes that have been identified and discussed repeatedly over the last 20 years or more are precisely the same ones mentioned in numerous other places (e.g. Foran et al. 1990; Morton and Price 1994; James et al. 1995). They are as follows:

Each of these threatening processes has been discussed at length elsewhere. Each has the potential to compromise the integrity of the refugia we have nominated. Indeed, some of the refugia exist primarily because some or all of those threatening processes do not exist in a particular location; this is the case especially with the Islands, which escape the effects of most of these problems (and, for that reason, managers fully understand the importance of continuing to ensure the exclusion of such effects from these islands). Although we have not exhaustively surveyed the management plans that might apply to all the refugia described here, it is clear that there is widespread recognition among managers of these problems. There are formidable technical barriers to be overcome, as well as social and political effects, before such threatening processes can be brought under control. What is the prognosis for such advances?

Is there any evidence that refugia might be important for maintenance of natural populations which help regulate pest outbreaks, or assist in reducing land degradation? The only example which emerged from our literature review concerns the straw-necked ibis Threskiornis spinicollis, which depends for breeding on some of the wetland refugia which have figured so prominently in our review. Straw-necked ibis are major predators of Orthoptera (grasshoppers and crickets) in farmlands (Carrick 1962), and thus the protection of their breeding refugia may enhance pest control. The Macquarie Marshes constitute an example of such an effect (Brooker 1992).

In brief, then, refugia in arid Australia suffer from the same threatening processes that affect the remainder of the landscape. Thus, management of refugia requires that the same suite of issues be addressed as have been widely discussed with respect to arid Australia in recent times. Despite the universal nature of these management issues, though, it must be recognised that the refugia identified in this report require the utmost care if their relictual, endemic and significant species are to persist. These refugia are some of the places where our community stands to lose the most unusual organisms unless our management improves. They might act as a stimulus to action, such that mitigation of the threatening processes described above benefits refugia first of all but spreads outward into the rest of the arid landscape.