The role of an accidentally introduced fungus in degrading the health of the Stirling Range National Park ecosystem in South Western Australia: status and prognosis
Newsome, D. (2003) The role of an accidentally introduced fungus in degrading the health of the Stirling Range National Park ecosystem in South Western Australia: status and prognosis. In: Lasley, W.L., Rapport, D.J., Damania, A.B., Rolston, D.E., Nielsen, N.O. and Qualset, C.O., (eds.) Managing for healthy ecosystems. Lewis Publishers, Boca Raton.
The ecological status of national parks and nature reserves is usually considered to be healthy when compared to intensively managed landscapes and land that has been cleared for agriculture. The Stirling Range National Park (Figure 40.1) is a large area (115,600 ha) of original vegetation that was designated national park status in 1913 (Underwood and Burbidge, 1993). It is a zone of exceptional biodiversity and contains 1500 plant species, 87 of which are endemic to the park. Historical records of vertebrate fauna show that the park supported 27 species of terrestrial mammals; however, 12 of these are now extinct. Their decline is largely attributed to predation by introduced carnivores (Friend and Muir, 1993). The avifauna is more diverse with 140 species recorded, 90 of which are known to have bred or breed in the park (Burbidge and Rose, 1993).
The park is now completely surrounded by cleared land comprising agricultural ecosystems, parts of which are showing signs of degradation in the form of land sanitization. The impact of this secondary salinity, brought about by clearing natural vegetation and perturbating the water table, is profound and obvious. Because of this, agricultural land is degraded, and conventional forms of agriculture and associated economic activity are rendered useless.
The Stirling Range by contrast appears to comprise a healthy ecosystem. Significantly, however, it is argued here that the Stirling Range ecosystem is in the process of being degraded. The loss of mammal species could perhaps be perceived as an indicator that ecosystem health has been compromised. A more serious threat to the Stirling Range ecosystem is in the form of an accidently introduced fungus, Phytophthora cinnamomi, which has been shown to kill a wide range of plant species. The disease manifestation is the development of chlorotic tissues, the death of leaves, and eventual plant death. It is referred to as dieback and is caused by the fungus preventing water uptake by the roots. Although the Stirling Range is a reserve and has therefore been subject to minimal disturbance, the disease continues to spread throughout the park.
|Publication Type:||Book Chapter|
|Murdoch Affiliation:||School of Environmental Science|
|Copyright:||2003 CRC Press|
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