In the 1980s, ecologists were locked in a debate about how best to preserve biodiversity. Which, they asked, was better: a single large reserve, or several small reserves? The debate was never resolved, but did direct research towards the issue of habitat fragmentation and its link with extinction.
By the 1990s, consensus had been reached. Habitat fragmentation was a threat to a great number of species facing extinction. To protect biodiversity properly, these artificially fragmented habitats needed be reconnected.
Not unlike the current “debate” over climate change, public appreciation of the issue - and government action - has lagged behind scientific understanding by a couple of decades. Recently though, the federal government has officially come around to the importance of biological corridors.
In early March, the Gillard government announced an ambitious wildlife corridor plan that aims to connect the landscape across multiple land tenures. The scheme would be funded to the tune of about a billion dollars by the carbon tax.
Some wildlife can persist in isolated fragments, others will use very thin wildlife corridors. But most species will only move a short distance unless they come across larger “stepping stone” patches. Corridors allow landscape-scale movement and dispersal by plants and animals alike, and provide options for climate change adaptation. Ecological findings like these are now informing modern landscape-scale planning for biodiversity conservation.
Misconceptions about corridors
Scientific support is one thing, but for governments to sell this idea to the public and harness widespread support, misconceptions (and misinformation) about biological corridors need to be dispelled.
First, forget what you imagine from the word “corridor”. Good biological corridors are not tiny, feeble ribbons of habitat in the landscape, but broad continental-scale swaths tens of kilometres wide and hundreds or thousands of kilometres long.
These corridors take in native habitat across national parks, nature reserves, state forests, and remnant patches of habitat on farms and other private-held lands. Where necessary, tree-planting or other remediation is done to fill the gaps.
Which leads to a second misunderstanding: that “connectivity” is just about corridors, and we need a Herculean tree-planting scheme to achieve it. Connectivity Conservation uses a landscape-scale approach to conservation. For most of the government’s proposed corridors, the vast majority of habitat is already there. So corridors are mostly about managing that existing landscape holistically.
Neither native plants and animals - nor feral animals or weeds - recognise the artificial boundaries of parks, catchment management authorities, or private landholders. Good connectivity has as much to do with communication and adoption of the latest science and planning strategies as it does with creating new corridors.
Sure, plantings are part of the equation, and being guided by the best science is important. But, a good corridor network is only as good as the people on the ground making the necessary changes and adopting the right attitude for a more sustainable landscape - one that benefits both natural and agricultural ecosystems.
It’s no coincidence that most of Australia’s threatened species and ecosystems are on private lands. Steep and infertile lands are well protected by national parks and nature reserves, but productive lands in private ownership are where losses have been the greatest.
The national parks estate, without doubt, plays a pivotal role in a whole-of-landscape approach. But if they aren’t connected to adjacent forests and farmland, these reserves risk becoming islands of habitat, locked away from a surrounding matrix of competing land uses.
The important role of connectivity, and of all landholders contributing to conservation, was highlighted recently by a global study that showed increasing the number of national parks alone cannot halt the dramatic loss of biodiversity.
Creating a world-class corridor network
No amount of public awareness of the importance of corridors can ultimately make the plan a success. To be truly world-standard and cutting edge, the plan needs to have a strategic approach to improving connectivity.
It will need to have clear and measurable goals, for both ecological and social outcomes.
Initiatives will need to have access to spatial planning tools, such as those used in the Murrumbidgee Catchment Management Authority, and must operate within an adaptive management framework.
A scientifically credible and long term monitoring program should be a key part of this framework.
A recent CSIRO review of existing landscape scale corridor initiatives in Australia found that there’s no shortage of willingness to make the large-scale and long-term changes necessary for these initiatives to work. In fact, the major challenge for the Australian Government is to “create the enabling conditions needed to attract far greater investment in time, talent and financial capital to match the scale of need and ambition”.
Scientists have pointed to the value of corridors for wildlife, the public are receptive, and the government is backing the process with serious dollars. What we now must ensure is that ecologists and land managers continue to inform the process as it moves forward through the corridors of power, so that biodiversity really benefits.