REGARDLESS of the merits and values of individual national parks and nature reserves, Australia's conservation reserves do not ensure the survival of the continent's biota. There are many reasons for this. Reserves, even the largest, are too small and vulnerable to broad area disturbance. Consider that, in January 2003, fires burnt more than two-thirds of Kosciuszko National Park, which at 690 000 ha is the largest park in New South Wales and one of the largest in Australia. This shows how even the largest conservation reserves are at risk of catastrophic disturbance. The much smaller Nadgee Nature Reserve (21 000 ha) in southeastern New South Wales has burnt almost in its entirety twice in the 35 years I have worked there. The Nadgee fires and those in Kosciuszko were started by lightning and were the result of prolonged drought, events common across the continent. When small size is coupled with isolation, the long-term survival of populations and the exchange of propagules within the reserve system becomes problematical. Small size and isolation do not leave much scope for plants and animals to adapt to long-term climate change, either through dispersal or by evolution. Even reserving 10 or 15% of land for nature conservation, as recommended by some international conservation agencies, will be inadequate; a target of 30% would have better ecological credentials, but even this could prove inadequate unless the nature conservation reserve system was designed to allow for long-term evolutionary change, which it is not (see Archer 2002; Recher 2002a,b).
What makes long-term perspectives endure? Lessons from Dutch nature conservation