Ecological Armageddon in forest fragments

Malaysian rainforest. Image – jswakins/Flickr

An international team of scientists including the University of Adelaide’s Professor Corey Bradshaw has found that species living in rainforest fragments could be far more likely to disappear than was previously assumed.

Published today in the leading journal Science, the researchers outlined a study spanning two decades in which they witnessed the near-complete extinction of native small mammals on forest islands created by a large hydroelectric reservoir in Thailand.

“Tropical forests remain one of the last great bastions of biodiversity, but they continue to be felled and fragmented into small ‘islands’ around the world,” says co-author Professor Corey Bradshaw, Director Ecological Modelling at the University of Adelaide’s Environment Institute.

“This study shows we need to be even more concerned than we thought – the speed at which there was near-total loss of native small mammals was alarming and shows that leaving fragments of forest behind is not nearly enough to protect these species.”

“It was like ecological Armageddon,” says Luke Gibson from the National University of Singapore, who led the study. “Nobody imagined we’d see such catastrophic local extinctions.”

The study was motivated by a desire to understand how long species can live in forest fragments. If they persist for many decades, then this gives conservationists a window of time to create wildlife corridors or restore surrounding forests to reduce the harmful effects of forest isolation.

However, the researchers saw native small mammals almost vanish at great speed, with just a handful remaining – on average, less than one individual per island – after 25 years.

As well as suffering the effects of population isolation, the small mammals also had to deal with a devastating invader – the Malayan field rat. In just a few years, the invading rat virtually displaced all native small mammals. The field rat normally favours villages and agricultural lands, but will also invade disturbed forests.

“This tells us that the double whammy of habitat fragmentation and invading species can be fatal for native wildlife,” says Dr Antony Lynam, from the US-based Wildlife Conservation Society. “And that’s frightening because invaders are increasing in disturbed and fragmented habitats around the world.”

“The bottom line is that we must conserve large, intact habitats for nature,” says Luke Gibson. “That’s the only way we can ensure biodiversity will survive.”

Near-complete extinction of native small mammal fauna 25 years after forest fragmentation is published in Science and is available at www.sciencemag.org.

Prevention is better than the cure: Research priorities for global biosecurity

The Environment Institute (University of Adelaide) are delighted to present a public seminar by Professor David Lodge, University of Notre Dame, Indiana.

Professor David Lodge

Date: Tuesday October 8^th 2013 5pm

Venue: Ira Raymond Exhibition Room, Barr Smith Library, University of Adelaide North Terrace Campus, Adelaide SA 5005

Contact details: environment@adelaide.edu.au

BOOK HERE 

Professor Lodge is one of the world’s leading researchers working in global change biology and invasion ecology. With expertise in land-water links, invasive species, and environmental policy, his research critically examines how our activities impact, and continue to change, the habitats that provide us with drinking water, recreation and fisheries, and valuable biodiversity. Some of the key questions that Professor Lodge’s research addresses include:

• What has led to the global eutrophication of inland lakes and seas?
• What is the impact of changes in biodiversity, and the increasing dominance of invasive species, on aquatic systems?
• When the costs to control invasive species far exceed the cost to prevent, why don’t we invest more in prevention?

In Australia, the threats to environmental resources and amenities are multiplying, putting pressure on our communities and economies. These pressures are predicted to accelerate with increasing human use of the landscape and limited water supplies, as well as the human-assisted movement of plant and animal species from one place to another. What are the risks to our health and wellbeing?

Come listen and learn from Professor Lodge as he shares his international insights on biological invasions and biosecurity risk.

Predicting publishing success in scientists.

Men with printing press circa 1930s
Image – Flickr/ Seattle Municipal Archives.

A provocative new study suggests it is straightforward to predict which academics will succeed as publishing scientists.

Those who publish earlier and more often while young are typically the long-term winners.

“We were really surprised,” said Professor William Laurance of James Cook University in Cairns, Australia, who led the study.

“It doesn’t matter if you go to Harvard or a low-ranked university. If you begin publishing scientific articles when you’re still a graduate student, you are far more likely to succeed in the long run.”

Laurance’s team scrutinized more than 1400 biologists on four continents, and then selected 182 to study intensively.

They found the researchers varied greatly – by almost a hundred-fold – in the number of scientific articles they published during their careers.

“For reasons that are not totally clear, some people just ‘get’ the publishing game early in their careers, and it’s these scientists who are most likely to keep on publishing strong research,” said Professor Corey Bradshaw of the University of Adelaide’s Environment Institute in South Australia.

Another finding was that women faced some disadvantages in publishing research, even those who overcame the well-documented attrition of senior female academics.

“Women have to jump a lot of hurdles in science,” said Carolina Useche of the Humboldt Institute in Colombia. “Family responsibilities weigh heavily on them, and they don’t seem to promote themselves as aggressively as some men do.”

Language also plays a role, according to Ms Useche. “Those who grow up speaking and writing English have an advantage, because most scientific journals are in English,” she said.

The research team reached two key conclusions.

First, far too few women make it to the top in science, in large part because they do not, on average, publish as often as men.

“For women scientists, it’s just not a level playing field, and we need to find ways to help them advance professionally,” Professor Bradshaw said.

Second, those who publish early and often are most likely to become scientific superstars, regardless of the international standing of the universities where they obtained their PhD.

“We need to pay a lot of attention to the early training of scientists,” Professor Laurance said. “If we do a good job, we can give them a head start that will last their whole lives. This research gives us a good evidence base for our efforts.”

 

Predicting publication success for biologists by William F. Laurance, D. Carolina Useche, Susan G. Laurance, and Corey J. A. Bradshaw was just published online in BioScience: http://www.jstor.org/discover/10.1525/bio.2013.63.10.9?uid=3737720&uid=2129&uid=2134&uid=2&uid=70&uid=4&sid=21102642299977

 

Further evidence on human global warming

Professor Tim Wigley

A team of international climate scientists including University of Adelaide’s Professor Tom Wigley has today reported further strong evidence of the human influence on climate change.

Published today in the Proceedings of the National Academy of Sciences of the USA (PNAS), the researchers have detailed a comprehensive study investigating the causes of temperature changes in Earth’s atmosphere.

They have analysed satellite temperature data over 34 years and compared these data with results from more than 20 different climate models, focussing on the vertical structure of atmospheric temperature change (from the troposphere or lower levels of the atmosphere through to the stratosphere or upper reaches of the atmosphere).

The study was led by scientists from the Lawrence Livermore National Laboratory in the United States and builds on work published in 1996 by the same group. The 1996 Nature paper, ‘A search for human influences on the thermal structure of the atmosphere’, was the first published work to clearly identify the human fingerprint in observed temperature changes.

“With this paper we have built on our earlier work with another 20 years of data that adds further strong evidence for the human impact on our climate,” says Professor Wigley, ARC Fellow with the University of Adelaide’s Environment Institute.

Professor Wigley says the study is more much comprehensive than other published studies and has been able to better define the human ‘signal’ in atmospheric temperature change. There is a clear pattern of warming temperatures in the troposphere and cooling temperatures in the stratosphere, changes that are the characteristic signature of human activity.

“The main thing is that we can identify what is called a human fingerprint, or a distinctive pattern of change in the observational record, and that pattern is derived from climate modelling experiments,” he said.

“We look at patterns of change that can be attributed to other things, such as changing output of the sun for example, and we show that those cannot be identified in the observational record. 

“We can see the human fingerprint, we can’t see the fingerprint of any other cause, and so it’s pretty obvious that the only explanation is there’s been a very distinctive human influence on the patterns of climate change.”

The scientists said more had been done to tackle ozone depletion than the effects of greenhouse gases.

“Greenhouses gases trap the warmth in, they allow radiation from the sun to penetrate to the lower layers of the atmosphere, but they don’t allow as much outgoing radiation and that’s what’s called the greenhouse effect,” Professor Wigley said.

“One of the standard skeptic ‘arguments’ is that all the observed changes are caused by natural variability, and often supposed to be due to solar activity,” says Professor Wigley.

“What we have shown beyond a shadow of doubt is that the climate changes we are observing cannot be due to the Sun or any other natural factors.

“There is simply no other way to explain the changes that have occurred since 1979 (when special research satellites were introduced by the US National Oceanic and Atmospheric Administration) other than as a result of human influences – primarily greenhouse gases and related pollutants like sulphur dioxide emissions and gases that affect the atmospheric concentrations of ozone.

“Other published work has already shown a convincing and growing pile of pebbles of evidence for the dominant role of humans in climate change. Our paper adds a huge boulder to that pile.”

Find the paper here. 

Read a longer interview with Professor Wigley here. 

Barry Brook wins prestigious Scopus award.

 Professor Barry Brook, one of our leaders at the Environment Institute has won the Life Sciences category of the 2013 Scopus Young Researcher Awards.

The Scopus award recognizes researchers under the age of 40 for their output, impact and contribution to their field. Recently, Barry’s work has focused on climate change and biodiversity loss.

Not only has Barry authored over 240 papers, he is in the top 0.1% of cited scientists in environmental and ecology research in the past decade and has attracted more than $18M in funding.

On top of producing all this work, Barry is dedicated to science communication and outreach. His blog Brave New Climate has received over 3.5 million hits since it started in 2008.

“Impact matters, and citations of publications are a vital metric for measuring effectiveness of a scientist. It’s great to be recognised by the Scopus Young Researchers Award 2013 as being someone whose work is being used and built upon by the world’s research community,” says Barry

“For me to be awarded the Life Sciences prize communicates clearly to potential future research stars — from aspiring high-school kids to postgraduate science students — that ecology and conservation biology is an exciting and high-impact discipline where you can make a real difference. It’s a great area in which to work.

“I always try to ensure that my research findings have the highest likelihood of reaching a wide audience. My view is that whether your goal as a scientist is to inform and fascinate the general public, or to change on-ground management practices and influence policy, quality publications and good communication are key.”

Below Barry explains some of his research and its impact with Professor Corey Bradshaw.

Dingo wrongly blamed for extinctions

Dingo , Fraser Island. Image – ogwens/Flickr

Dingoes have been unjustly blamed for the extinctions on the Australian mainland of the Tasmanian tiger (or thylacine) and the Tasmanian devil, a University of Adelaide study has found.

In a paper published in the journal Ecology, the researchers say that despite popular belief that the Australian dingo was to blame for the demise of thylacines and devils on the mainland about 3000 years ago, in fact Aboriginal populations and a shift in climate were more likely responsible.

“Perhaps because the public perception of dingoes as ‘sheep-killers’ is so firmly entrenched, it has been commonly assumed that dingoes killed off the thylacines and devils on mainland Australia,” says researcher Dr Thomas Prowse, Research Associate in the School of Earth and Environmental Sciences and the Environment Institute.

“There was anecdotal evidence too: both thylacines and devils lasted for over 40,000 years following the arrival of humans in Australia; their mainland extinction about 3000 years ago was just after dingoes were introduced to Australia; and the fact that thylacines and devils persisted on Tasmania, which was never colonised by dingoes.

“However, and unfortunately for the dingo, most people have overlooked that about the same time as dingoes came along, the climate changed rather abruptly and Aboriginal populations were going through a major period of intensification in terms of population growth and technological advances.”

The researchers built a complex series of mathematical models to recreate the dynamic interaction between the main potential drivers of extinction (dingoes, climate and humans), the long-term response of herbivore prey, and the viability of the thylacine and devil populations.

The models included interactions and competition between predators as well as the influence of climate on vegetation and prey populations.

The simulations showed that while dingoes had some impact, growth and development in human populations, possibly intensified by climate change, was the most likely extinction driver.

“Our multi-species models showed that dingoes could reduce thylacine and devil populations through both competition and direct predation, but there was low probability that they could have been the sole extinction driver,” Dr Prowse says.

“Our results support the notion that thylacines and devils persisted on Tasmania not because the dingo was absent, but because human density remained low there and Tasmania was less affected by abrupt climate changes.”

The study ‘An ecological regime shift resulting from disrupted predator-prey interactions in Holocene Australia’ also involved Professors Corey Bradshaw and Barry Brook from the University of Adelaide’s Environment Institute and Professor Chris Johnson from the University of Tasmania.

World’s rarest cat under threat from a changing climate.

Image – Iberia Nature

A new international study including members of the Environment Institute, Damien Fordham and Barry Brook, has found the world’s most endangered cat species, the Iberian lynx, could be driven to extinction within 50 years due to climate change.  Published today in Nature Climate Change,

“We show that climate change could lead to a rapid and severe decrease in lynx abundance in coming decades, and probably lead to its extinction in the wild within 50 years,” says lead author Dr Damien Fordham. “Current management efforts could be futile if they don’t take into account the combined effects of climate change, land use and prey abundance on population dynamics of the Iberian lynx.

Estimates indicate only 250 individuals survive in two populations on the Iberian Peninsula.  Its decline has been linked to sharp regional reductions in its main prey species, the European Rabbit.

“Models used to investigate how climate change will affect biodiversity have so far been unable to capture the dynamic and complex feedbacks of species interactions,” says Dr Miguel Araújo, senior author and Spanish Research Council (CSIC) Senior Researcher at the National Museum of Natural Sciences in Madrid. “By developing new forecasting methods, we have managed, for the first time, to simulate demographic responses of lynx to spatial patterns of rabbit abundance conditioned by disease, climate change, and land use modification.”

Since 1994 over €90 million has been spent on saving the Iberian lynx including reintroductions into suitable habitats. Although there is evidence that lynx numbers have increased in the last ten years in response to intensive management, this study warns that the ongoing conservation strategies could buy just a few decades before the species goes extinct. This study is the most comprehensive conservation-management model yet developed of the effects of climate change on a predator and its prey.

CSIC researcher at the Estación Biológica de Doñana in Seville, Dr Alejandro Rodríguez, says: “Habitat in the south-west of the Iberian Peninsula, where the two existing populations of lynx persist, is most likely to be inhospitable to lynx by the middle of this century.”

“That the numbers of Iberian lynx are currently increasing suggests that intensive management of habitat and rabbit populations have worked as effective short-term conservation strategies, but small population size means that the species is still threatened and susceptible to future population declines,” says Professor Barry Brook, Chair of Climate Science at the University of Adelaide. “This means that the species is extremely vulnerable to shifts in habitat quality or to changes in the abundance of their rabbit prey due to climate change.”

The researchers say climate-change-informed decisions should be a common part of conservation practice.

Read the publication here.

Making national parks truly national.

Kakadu National Park – Flickr/Marc Dalmulder

Environment Insitute member Corey Bradshaw co-authored this piece on The Conversation on June 14, 2013.

Australia boasts over 500 national parks covering 28 million hectares of land, or about 3.6% of Australia. You could be forgiven for thinking we’re doing well in the biodiversity-conservation game.

But did you know that of those more than 500 national parks, only six are managed by the Commonwealth Government? For marine parks, it’s a little more: 61 of the 130-plus are managed primarily by the Commonwealth. This means that the majority of our important biodiversity refuges are managed exclusively by state and territory governments. In other words, our national parks aren’t “national” at all.

In a world of perfect governance, this wouldn’t matter. But we’re seeing the rapid “relaxation” of laws designed to protect our “national” and marine parks by many state governments. Would making all of them truly national do more to conserve biodiversity?

One silly decision resulting in a major ecosystem disturbance in a national park can take decades if not hundreds of years to heal. Ecosystems are complex interactions of millions of species that take a long time to evolve – they cannot be easily repaired once the damage is done.

The full article can be accessed here.

Overgrazed land restoration study underway

 

Monarto Zoo is playing host to an overgrazed land restoration study led by the University of Adelaide, with partners including Zoos South Australia and the University of Queensland.

The purpose of the study, which will take 30 years to complete, is to identify the most effective methods in restoring overgrazed land back to native woodland. 10 hectares of previously farmed land is being planted with a variety of native species at different planting densities. The focus for this study is on the restoration of the woodland areas of the Mount Lofty Ranges.

Environment Institute member and Project Leader Professor Corey Bradshaw says, “Across Australia we’ve lost 40% of our forest cover, but in the Mount Lofty Ranges we’ve lost 90% and the fragments that are left are so small that they don’t provide adequate habitats for native fauna. We’ve already lost about 130 species of plants and animals and there are major extinctions to come.

“What we are asking is how many different species – and in what densities – are required to restore a native woodland from an over-grazed paddock, to provide the biggest long-term biodiversity and carbon benefits simultaneously for the lowest cost.”

Zoos SA Australian Conservation Manager Dr Phillip Ainsley says, “We want to understand what produces the best carbon production outcomes and biodiversity responses and do this in the best and most cost effective way possible.”

The plantings will be based around the Mallee box gum, South Australian blue gum and various shrubby species. Survival and growth rates will be monitored along with the presence of native fauna – invertebrates, reptiles and eventually birds.

More from Prof Corey Bradshaw can be found on his blog Conservation Bytes.

A Brave New Green World: does a price on carbon help protect Australia’s biodiversity?

Phot by: Kris*M (Flickr)

As Australia shifts to cut greenhouse gas emissions is it also possible to enhance our biodiversity? A new peer-reviewed paper by Environment Institute members Corey Bradshaw and Barry Brook (with others) directly addresses this question, showing “biodiversity-related enhancement schemes (including environmental plantings and invasive species reduction) can be compatible with carbon-sequestration initiatives”.

The authors find that most land-management options to reduce or capture greenhouse gas emissions will offer clear advantages for biodiversity. These advantages increase the viability of native biodiversity. However, there are potential negative outcomes. The authors discuss what needs to be considered if biodiversity is to benefit from the new carbon economy.

Issues and opportunities include:

• Carbon plantings will only have real biodiversity value if they comprise appropriate native tree species and provide suitable habitats and resources for valued fauna.
• Plantings risk severely altering local water availability, quality and/or water movement.
• Fire can assist with some positive carbon outcomes such as prescribed burning to reduce the frequency of high-intensity wildfires in northern Australia, However, in southern Australia fire is currently unlikely to help but will become increasingly important for biodiversity conservation as the climate warms.
• Carbon price changes to agriculture can benefit biodiversity. Such changes include reductions in tillage frequency and livestock densities, reductions in fertiliser use, and retention and regeneration of native shrubs.

This is a complex area but “as long as biodiversity persistence is taken into account at the planning and implementation stages”, it is the authors’ opinions that carbon and biodiversity “goals are not mutually exclusive”. To achieve this “careful amalgamation of such carbon-mitigation approaches with other incentive schemes such as biodiversity offsets … will be required.”

The full findings, issues and opportunities are in the complete paper Brave new green world – Consequences of a carbon economy for the conservation of Australian biodiversity.

Highlights

► Australia’s new carbon price will have profound implications for land-use change. ► Major changes will arise from environmental plantings and regrowth & fire management. ► Other changes will affect forestry, agriculture and feral animal control. ► Most anticipated land-use changes should benefit biodiversity. ► Negative biodiversity outcomes could arise if changes focus exclusively on carbon.

To see the slide show of this presentation, visit Corey’s SlideShare page.