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Eco Logic

Eco Logic column

Grieving for the Past, Hoping for the Future

By Richard Hobbs

Many conservation scientists may be suffering from grief over the loss of species and habitats. If this is true, can an understanding of the grieving process be useful?

I have been increasingly struck by how divisive conservation science can be. For instance, I have been involved recently in discussions on the issue of non-native/invasive species and novel ecosystems.

In the case of non-native species, it’s been suggested that the emphasis should be shifted from considering primarily a species’ origin to a focus on the impacts species have on the ecosystems in which they establish. This sounds reasonable but subsequent critiques of this view revealed a degree of alarm, almost outrage, at the argument.

Richard Hobbs is a researcher with the Environmental Decisions Group. He is based at the University of Western Australia.

Tall or Sprawl?

By Jessica Sushinksy

How should we grow Australia’s cities to minimise their biodiversity impacts?

Should we build our cities up or out? That’s the question we asked when we considered the challenge of how a growing city can retain its wildlife. While it’s unrealistic to believe city living can co-exist with a full complement of bio­diversity, we wondered if there were differences in the impact of different growth strategies.

Jessica Sushinksy is a researcher with the Environmental Decisions Group ( This research was carried out while she was based at the University of Queensland.

The Value of More Information for Managing Koalas

By Sean Maxwell

Thinking like a multi-billion dollar mining magnate may help us better manage koalas.

Koalas in south-east Queensland are in trouble. They are threatened by vehicles, dog attacks and disease, and these threats are growing as koala habitat is cleared to make way for new housing and industrial estates. The rate of decline is alarming, with a significant population within south-east Queensland crashing from an estimated 6000 individuals to fewer than 2000 in the space of 15 years.

Sean Maxwell is a researcher with the Environmental Decisions Group. He is based at the University of Queensland.

The Resilience of the Reef (and Reef Tourism)

By Duan Biggs

The lifestyle values of reef tourism companies contribute to the resilience of those companies and to better conservation outcomes for the Reef itself.

The Great Barrier Reef is one of Australia’s most spectacular natural attractions. Tourism to the reef contributes $5.8 billion to the Australian economy per annum and sustains 55,000 jobs.

Yet coral reefs on the Great Barrier Reef and worldwide are under threat from climate change, overfishing, and land-based pollutants from agriculture and development. As a result there is concern over the future of the Great Barrier Reef’s tourism sector, and the communities that depend on it.

Duan Biggs is a researcher with the Environmental Decisions Group, and is based at the University of Queensland. This research was done with the ARC Centre of Excellence for Coral Reef Studies.

Fall of the Leviathans

By David Salt

Three of the world’s top forestry ecologists have warned that the planet’s stock of large, old trees is experiencing an accelerating decline.

They are among the biggest organisms on Earth, they form keystone structures in every landscape in which they are found, everyone loves them… and they’re disappearing before our eyes. Just as large-bodied animals such as elephants, tigers and many whales have declined drastically around the world, a growing body of evidence suggests that large old trees could be equally imperiled.

David Salt is a researcher with the Environmental Decisions Group at the Australian National University.

Cooperation and Conflict in Conservation

By Michael Bode

Different groups are all “fighting” for the environment, but each group does it in its own way and with its own specific priorities – sometimes leading to negative conservation outcomes.

Systematic conservation planning is the absolute best-practice approach to conserving biodiversity in a large landscape. We create maps that highlight the distribution of our favourite conservation features – be they threatened species, vulnerable habitats, ecosystem services, or all of the above – and then we use these data to decide which locations are the most valuable. The result is a priority map: a chart of where our limited resources will do the most good for conservation.

Are Two Fences Better Than One?

By Kate Helmstedt

Conservation fences are very effective in allowing threatened animals to breed, but when the population grows too much, managers must decide between extending the existing fence or building a new enclosure.

Fences are a key strategy in the conservation of threatened native species. Australia has more than 37 large conservation fences enclosing 27 species of bird, marsupial and reptile in more than 35,000 ha of predator-free habitat. On the Australian mainland, many of these species can no longer be found outside chain-link and electrified wire.

Kate Helmstedt is a researcher with the Environmental Decisions Group. She is based at the University of Queensland.

The Value of an Old Tree in the City

By Karen Ikin

Large old trees provide a significant biodiversity benefit that should be factored in by governments when managing biodiversity.

Large old trees are valued and protected in many of Australia’s city and suburban landscapes because of the environmental and economic benefits they provide. These include wind reduction, shade, storm water management and landscape improvement. The biodiversity benefit of old trees, however, is often forgotten and rarely quantified.

Karen Ikin is a researcher with the Environmental Decisions Group. She is based at the Australian National University.

The Reality of Biodiversity Offsets

By Martine Maron and Richard Hobbs

Many of the expectations for biodiversity offsetting remain unsupported by evidence.

Biodiversity offsetting is one of the fastest-growing areas in conservation policy, with more than 64 programs currently underway around the world. The idea is that losses of bio­diversity at an impact site are compensated by the generation of ecologically equivalent gains elsewhere. The result, in theory, is that there is “no net loss” of biodiversity.

Depending on who you talk to, biodiversity offsets represent either a great conservation opportunity or an attempt to greenwash “business as usual” for developers.

Martine Maron and Richard Hobbs are both researchers with the Environmental Decisions Group. Martine is based at the University of Queensland, and Richard is at the University of Western Australia.

Bioperversity in the Plantation

By David Salt

A narrow focus on carbon in commercial plantations could yield a number of unwelcome surprises.

Like it or not, the carbon economy is coming to town. No one can predict exactly what it will look like, but the bottom line is that emitting or capturing carbon is going to have a price.

One of the expected consequences of this is that income from carbon offsetting will drive major land management changes. Land owners will be shifting land to higher carbon storage states by transforming the vegetation cover. Many people say this is a good thing, with the potential to restore degraded land and better protect biodiversity.

David Salt is a science writer at the Australian National University and is part of the ARC Centre of Excellence for Environmental Decisions.