The legacy of past land clearance will continue to see habitat decline on private land through much of the sheep–wheat belt of Australia. Current efforts to reverse this effect are having only small success. If the current level of investment in reducing habitat decline continues or declines, then much of the sheep–wheat belt will see massive further loss of native vegetation due to death of old trees and limited recruitment of seedlings, and reduction in most species of mammals, birds, and reptiles, and many species of amphibians and invertebrates. This is likely to be associated with increased rates of soil erosion and other negative effects of extreme weather. The diversity of soil organisms, such as fungi, earthworms, beetles, spiders and a range of other invertebrates responsible for maintaining soil fertility and controlling pest outbreaks, is likely to decline. The current replacement of native species with a smaller number of introduced species capable of supporting a narrower range of ecological functions will intensify.
An explosion in the number and impacts of invasive species is plausible due to climate change and inadequate investment in understanding the interactions between climate change and outbreaks, and/or in detection and early intervention when an outbreak occurs. These problems are likely to be compounded if effective agreements are not reached to control the global movement of potentially invasive species, which could see Australia as the recipient of many species that are pre-adapted to outcompete Australian native species.
The current trend of declining resources for managing protected areas on public land and minimal investment in connecting protected areas is likely to result in a deterioration of these resources and an inability to cope with the effects of climate change. There is likely to be increased incidence and severity of pest and disease outbreaks and changes in where different species can find suitable climatic conditions.
Failure to manage native vegetation around urban centres is likely to see natural control of pests and diseases by native animals decrease and the costs of control by chemical methods increase. Impacts from extreme weather (including damage from floods and winds) are likely to increase. Costs of water purification are likely to increase due to the decline of native vegetation in water catchments and increased movement of soils into water supplies. As the area and quality of remnant native vegetation decline, a tipping point is likely to be reached beyond which decline is hastened by reduced numbers and diversity of pollinating species.
Climate change is likely to exacerbate most of these trends, while increasing the extremes of impacts and the uncertainty of challenges and opportunities. There is a risk that progress will not be made on governance approaches that allow better anticipation of, and preparation for, future shocks, or on effective cooperation and synergy between governments at all levels and communities to detect and respond to challenges and opportunities. If this progress is not achieved, then both ecosystems and the social systems whose prosperity is coupled with them are likely to become increasingly unresilient and vulnerable to environmental shocks, as well as market volatility and other economic fluctuations.
Finally, as the Australian population grows, periods of resource deficiency and stresses on quality of life in both urban and regional communities are likely if we do not pay serious attention to our dependence on biodiversity and natural resources.