A fine balance: saving Australia’s unique wildlife in a contested land

A golden-tailed gecko – one of the inhabitants of the Brigalow Belt. Eric Vanderduys, Author provided.

Rocio Ponce-Reyes, CSIRO; Danial Stratford, CSIRO; Iadine Chadès, CSIRO; Jennifer Firn, Queensland University of Technology; Josie Carwardine, CSIRO; Sam Nicol, CSIRO; Stuart Whitten, CSIRO, and Tara Martin, CSIRO

The Brigalow Belt in Queensland is a national hotspot for wildlife, especially for birds and reptiles. Many of these, such as the black-throated finch, golden-tailed gecko and brigalow scaly-foot are found nowhere else in the world.

But the region is also one of the most transformed and contested areas in Australia. People want to use the Brigalow for many different things: conservation, grazing, agricultural production, mineral and gas extraction. This region also overlaps with the country’s largest reserves of coal and coal seam gas.

Together, the economic activities in the region bring land clearing, changes to water sources, invasion of exotic species and changed fire patterns, which threaten the region’s unique biodiversity.

Currently, at least 179 species of plants and animals are known to be threatened in the region. In research published today we look at the best way to conserve these species, attempting to balance the competing uses of this region.

The Brigalow Belt in Queensland.

Meet the locals

The Brigalow Belt bioregion takes its name from the Aboriginal word “brigalow” that describes the region’s dominant tree species (Acacia harpophylla). Brigalow trees can grow up to 25 metres in height and are characterised by their silver foliage.

Brigalow trees – a relative of the golden wattle, Australia’s national floral emblem.
Rocio Ponce-Reyes, Author provided

Brigalow ecosystems once formed extensive open-forest woodlands that covered 30% of the region, but since the mid-19th century about 95% of their original extent has been cleared, mostly for farming. The remaining 600,000 hectares of relatively small, isolated and fragmented remnants of brigalow forest are now protected as an endangered ecological community. The Semi-Evergreen Vine Thicket, or bottle tree scrub, is also listed.

Mammals are the most threatened group of the region. Eight species are already extinct, some of them locally (such as the eastern quoll and northern bettong) and others globally (such as the Darling Downs hopping mouse).

Other iconic mammals in the region include the bridled nail-tail wallaby and the northern hairy-nosed wombat. Both are listed as endangered at federal and state levels.

Long history of transformation

Traditional owners managed the region, including through burning practices, until the arrival of the first European settlers in the 1840s. Since then, management practices have changed markedly, especially with the establishment of the Brigalow and Other Lands Development Scheme in the 1950s.

This scheme provided new settlers, including many soldiers returning from the second world war, with infrastructure, financial assistance and a block of bushland. In return, they were expected to clear their land and establish a farm within 15 years to support the growing Queensland population.

Since then, the rate of clearing of Brigalow has varied in response to changes in legislation through time.

The black-throated finches of the Brigalow are regarded as endangered.
Eric Vanderduys, Author provided

The Brigalow’s silver lining

There are many ways of dealing with the threats facing the Brigalow’s biodiversity. But which gives us the most bang for our buck?

We worked with 40 key stakeholders from the region to answer this question.

You might think there’s a simple answer: stop development. However, native plants and animals in the Brigalow region are threatened by an accumulation of past, current and future land uses, and all need to be addressed to save these species.

Stakeholders focused on the strategies they believed to be the most feasible and achievable for minimising negative impacts and managing threats arising from all land uses in the region. The strategies, listed below, target several threats posed by industries in the region, such as agriculture, grazing, coal mining and coal seam gas.

  1. Protect remnant vegetation
  2. Protect important regrowth vegetation
  3. Establish key biodiversity areas, such as identify and manage areas of critical habitat
  4. Restore key habitats
  5. Manage pest animals such as feral cats, pigs and noisy miners
  6. Manage invasive plants
  7. Manage fire
  8. Manage grazing
  9. Manage water
  10. Manage pollution
  11. Build a common vision

The stakeholders included a strategy to “build a common vision” because they saw this as vital to achieving the other strategies. This common vision would be built by stakeholders to identify shared goals that balance environmental, social and economic considerations, such as the extent and nature of future developments.

Not a snake, but a legless lizard: the Brigalow scaly foot.
Eric Vanderduys, Author provided

We discovered that managing fire and invasive plant species would provide the best bang for our buck in terms of protecting the Brigalow Belt’s threatened plants and animals. Protecting remaining stands of vegetation offered high benefits to native wildlife, but came at high economic costs. We also discovered that building a common vision will improve the effectiveness of the other management strategies.

Experts estimated that it would cost about A$57.5 million each year to implement all 11 proposed management strategies in the Brigalow Belt. This is around A$1.60 per hectare each year.

If we don’t make this investment, it’s likely 21 species will disappear from the region over the next 50 years. But if we implement the 11 strategies, 12 of these species will likely survive (including the regent honeyeater, northern quoll and bridled nail-tail wallaby) and the outlook of many other species will improve. Species-specific recovery plans may help stop the other nine species (such as the northern-hairy nosed wombat and the swift parrot) from being lost from the region.

When it comes to saving species, working together with a common vision to balance the needs of wildlife and people will deliver the best outcomes in this contested region.

The Conversation

Rocio Ponce-Reyes, Postdoctoral Research Fellow, CSIRO; Danial Stratford, Senior experimental scientist, CSIRO; Iadine Chadès, Senior research scientist, CSIRO; Jennifer Firn, Associate professor, Queensland University of Technology; Josie Carwardine, Research Scientist, Ecosystem Sciences, CSIRO; Sam Nicol, Postdoctoral Researcher, Ecosystem Sciences, CSIRO; Stuart Whitten, Group Leader, Economics and Future Pathways, CSIRO, and Tara Martin, Principal Research Scientist, CSIRO

This article was originally published on The Conversation. Read the original article.

Protecting Australia’s Lake Eyre basin means getting our priorities right

The yellow-footed rock wallaby is just one of the rare species found in the Lake Eyre Basin. Angus Emmott, Author provided.

Jennifer Firn, Queensland University of Technology; Andrew Reeson, CSIRO; Belinda Walters, CSIRO; Hugh Possingham, The University of Queensland; Iadine Chadès, CSIRO; Jean-Baptiste Pichancourt, CSIRO; Josie Carwardine, CSIRO; Ramona Maggini, The University of Queensland; Rocio Ponce-Reyes, CSIRO; Sam Nicol, CSIRO, and Tara Martin, CSIRO

Australia’s Lake Eyre is perhaps best known as the continent’s largest lake, and for the rare floods that bring the desert to life.

But Lake Eyre is much more than a lake. Taking into account the rivers that drain into it and where they come from, the Lake Eyre Basin is one of largest inland draining systems in the world, the size of Germany, France and Italy combined. It is home to many natural wonders, such as Uluru, and many species of threatened wildlife.

It is also threatened by invasive animals and plants, and climate change. How can we best protect the basin, given finite funds?

In two studies (published this week in Global Change Biology and the Journal of Applied Ecology) and in two CSIRO reports we show that managing feral pigs is one of the most effective ways to ensure the basin remains healthy in the future.

Introducing Lake Eyre (Kati Thanda)

Ecosystems in the Lake Eyre Basin are intimately connected when rainfall is high and water is flowing through three major river systems. Decisions within the four states that manage the basin – Northern Territory, Queensland, South Australia and New South Wales – will impact neighbouring habitats.

Australia’s Lake Eyre Basin covers 120 million hectares. This huge area of the outback has a rich and thriving Indigenous culture stretching back tens of thousands of years, with Indigenous people making up 40-90% of the population.

Firn et al.

The basin contains natural and cultural assets such as Kati Thanda-Lake Eyre, Uluru, Coongie Lakes and other internationally important wetlands.

There are threatened “mound springs” (EPBC Act 1999, which are permanent wetlands in arid ecosystems fed by the water from the Great Artesian Basin that provide refuge for at least 13 plant species and 65 animal species that occur nowhere else on earth.

The basin is also home to many other unique, rare, threatened species such as the greater bilby, yellow-footed rock wallaby, night parrot, grey falcon and letter-winged kite.

Mound springs are home to many unique species.
Angus Emmott, Author provided

Threats to the basin

Invasive species and climate change are two things scientists are most concerned about in the Lake Eyre Basin.

The basin is already characterised by a highly variable climate and climate change impacts are predicted to increase this variability.

Grey Falcon
Angus Emmott, Author provided

Significant pressures are threatening the natural systems of the Lake Eyre basin, with exotic animals’ and plants’ establishment and spread being major concerns.

Climate change is also a major concern as it is altering the habitat suitability for many native species and may increase the severity of other threats, such as invasive species.

Invasive animals can reproduce and spread quickly, as they are highly adaptable to changing weather and biotic conditions. This combined pressure from climate change and invasive animals will impact on threatened native species already disadvantaged by habitat and environmental conditions.

We estimated that 29 species (including the greater bilby) would be at risk of extinction thanks to climate change, unless we manage other threats.

Getting our priorities right

Letter winged kite
Angus Emmott, Author provided

Management across such a large area like the basin is expensive, so smart decisions are necessary to make sure resources are used as efficiently as possible.

So we want to know managing which invasive species will give us the most bang for our buck. And we want to know that it will continue to pay off under a changing climate.

We combined local knowledge, scientific data and analyses to develop an efficient and rational set of strategies for managing the negative impacts of invasive species – the priority threat management approach.

After comparing 11 different strategies for managing invasive species (including dogs, cats, camels and rabbits) we found managing feral pigs proved the most cost-effective strategy overall.

Pigs impact many different native species (including flora and fauna). Experts estimated that pig control would have the highest uptake, a moderate cost and one of the highest benefits for threatened species.

Managing feral pigs would make the most difference at the least cost to the Lake Eyre Basin.
Angus Emmott, Author provided

The benefit for threatened native wildlife of controlling pigs was estimated to decrease when the climate change scenario was considered.

While managing pigs overall was the best strategy, if we focus on threatened mammals we find, perhaps unsurprisingly, that managing feral predators such as cats, dogs, and foxes is the best option.

Invasive animals also impact on agriculture so managing them for biodiversity increases agricultural productivity. We found that managing predators (cats, dogs and foxes), goats and rabbits, would potentially increase agricultural productivity by 10% or more.

We also found we would need to reduce invasive plants by 30% to reduce their impact, particularly parkinsonia, chinee apple and mesquite.

We have limited funds for protecting Australia’s environment. Prioritising what action we take can help preserve our unique biodiversity now and into the future.

The Conversation

Jennifer Firn, Associate professor, Queensland University of Technology; Andrew Reeson, Behavioural Economist, CSIRO; Belinda Walters, Research Support Officer, CSIRO; Hugh Possingham, Director ARC Centre of Excellence for Environmental Decisions, The University of Queensland; Iadine Chadès, Senior research scientist, CSIRO; Jean-Baptiste Pichancourt, Senior Research Fellow in Ecology, CSIRO; Josie Carwardine, Research Scientist, Ecosystem Sciences, CSIRO; Ramona Maggini, Honorary Research Fellow, The University of Queensland; Rocio Ponce-Reyes, Postdoctoral Research Fellow, CSIRO; Sam Nicol, Postdoctoral Researcher, Ecosystem Sciences, CSIRO, and Tara Martin, Senior Research Scientist, CSIRO

This article was originally published on The Conversation. Read the original article.