Abstract
The Stirling Range National Park lies within the south west Botanical Province of Western Australia, which is an acknowledged center of biodiversity and endemism of international significance. It is an important conservation reserve, genetic resource and nature based tourism destination. The mountain scenery and diverse array of wildflowers attract up to 100,000 visitors a year. Biologically the park contains a diverse flora, with 500 plant species, which includes 82 endemics and constitutes 20% of the flora of Western Australia. The health of the Stirling Range ecosystem is being compromised by the spread of an exotic fungus (Phytophthora cinnamomi) accidentally introduced when the road network was expanded through the national park. The fungus has since been spread along roads and fire-control corridors by infected soil being carried on the wheels of vehicles. More recently it has become apparent that walkers, by carrying infected soil on their boots, have spread the disease along mountain pathways. In south Western Australia up to 2000 of the indigenous plants are susceptible to the pathogen. Ecosystem response to the infection has resulted in reduced biodiversity and altered structural composition of the plant communities. Widespread loss of dominant or keystone plant species is likely to impact on dependent faunal populations. This study highlights the role of exotic organisms in degrading ecosystem health and the need for active management in tourism centered protected areas.