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.
James Jenkin
EFL Teacher Trainer
The article assumes wildlife corridors work. It's now a matter of how to make them happen.
However, there seems to be significant disagreement about the effectiveness of corridors. From New Scientist (http://newscientist1.blogspot.com.au/2012/02/environment-wildlife-corridors-could-be.html):
'One study investigated the genetic diversity of small marsupials in a narrow forest corridor traversing 4.5 kilometres of grazed grasslands in Queensland, Australia. It found that genetically distinct populations had persisted at either end. Mixing was a myth (Landscape Ecology, vol 21, p 641).'
Can any experts comment and help to round out the picture?
Ian Smith
PhD candidate (ecology)
With anything ecology: it depends.
ecosystems, species type, mobility, width, riparian areas, amount of vegetation in the region, pest species etc etc etc.
This isn't helped by the fact that you cant find anyone who can run an experiment that involves 50-100 years of regrowth and revegetation of 100's of ha.
Regardless even if corridors don't work for mammals (many of which need hollows and not new revegetation) they may work for other less "sexy" species that don't get researched.
Read moreThere…
Tom Barrett
Research Fellow, Landscape Ecologist at University of New England
Hi James,
I believe there are two questions to answer here:
1. Does structural connectivity facilitate movement and improve the resilience of plant and animal populations and increase their chances of persisting into the future?
and the second is..
2. Does structural connectivity facilitate gene flow between populations or sub-populations of vertebrates (such as marsupials)? This is referred to as 'functional connectivity'.
There is broad agreement that the answer to question one is…
Read moreJames Jenkin
EFL Teacher Trainer
Thanks very much Tom for your detailed response - that's very informative!
Mark Merritt
Company Director
I believe the creation, maintenance and monitoring of habitat corridors will be a massive growth industry in the very near future. Enterprising businesses will soon realise this and create much employment for many rural Australians.
Cheers for now – Mark Merritt 0427 571 770
Tim Scanlon
Author and Scientist
I'm all for subsidisation of private land holders (farmers) to become paid environmental managers. Schemes like this run in other countries quite successfully. Landcare was well received until funding ceased or became erratic. I could see a more permanent environmental management fund being very successful.
But why is this being funded out of the carbon tax? Why isn't the carbon tax being used on converting us to renewable energies now?
David Arthur
n/a
"Why is this being funded out of the carbon tax"? An excellent question, Tim, that goes to the crux of the fiscal irresponsibility and feeble thinking that goes into taxation policy by both major Parties.
Governments of all persuasion introduce taxes, purportedly to address some inconsistency in the tax system, then go and allocate the revenue from that tax to some worthy cause or another. I recall a Medicare levy surcharge being used to fund a buyback scheme for firearms, then a military intervention…
Read moreSimon Kilbane
PhD candidate (Landscape Arch, Ecology) at University of Western Australia
Nice article, also opens the lid on the benefits and also the difficulty and problems associated with envisaging and potentially allocating land or 'designing' for national habitat networks.
Included in any ‘connectivity conservation’ scheme are environmental as well as cultural benefits. Personally, I see the carbon tax and attached funding as a fantastic way of creating a balance of both ecological and cultural benefits – the potential to tick a large number of boxes.
For instance, in South…
Read moreBernie Masters
environmental consultant at FIA Technology Pty Ltd, B K Masters and Associates
Thanks for the article which is informative and timely.
Read moreA few additional points to consider:
1. some scientists are worried that corridors can become sinks, in that faunal movements into them from larger remnants may result in the fauna's natural or exotic predators having easier access to them as they move along the corridor such that they're all eaten before they reach the next larger remnant at the end of the corridor. I'm not aware of any research confirming this concern but I think it'll…
Karl Vernes
Senior Lecturer, School of Environmental & Rural Science at University of New England
Thanks Bernie, and some good points raised. The issue of corridors as sinks has been tossed about, and may well be the case under certain circumstances, but I think you're right in that there is not a whole lot of evidence to suggest this to be the case generally. The New Scientist article mentioned earlier (http://newscientist1.blogspot.com.au/2012/02/environment-wildlife-corridors-could-be.html) talks of this too, but doesn't give any studies to support that happening. I do agree with your second…
Read moreTanya Vernes
Kimberley Program Manager, WWF-Australia
In my line of work I am often commenting on Environmental Impact Statements of various development projects, and one thing that crops up time and again is the inclusion of 'environmental corridors' within those development areas. On the surface they seem positive, yet when explored even just a little it is plain to see that they often offer little and sometimes almost no environmental benefits primarly due to the fact that proponents are prone to class areas set aside for roads, pipelines, water…
Read moreTom Barrett
Research Fellow, Landscape Ecologist at University of New England
Hi Tanya,
You have raised a very important issue, that of definition. From my observations the many and varied definitions and interpretations of the term 'corridor' has lead to a lot of confusion. A review of these definitions in relation to conservation corridors by Hess and Fischer (2001) suggested one way of dealing with this ambiguity:
"We reject the notion of defining ‘corridor’ succinctly, because of the complex and multiple functions a corridor may serve. Instead, we suggest that conservationists and planners consider and document explicitly all of the possible functions of corridors when designing them. Addressing explicitly these functions when designing a corridor should eliminate much of the confusion surrounding their roles, and focus attention on establishing design criteria for corridors that function as intended."
http://carmelacanzonieri.com/library/6123/Hess-CommunicatingClearlyConsvCorridors.pdf
Tom.