Welcome to the second edition of Double Trouble, part of the Invasive Species Council’s work raising awareness about the dangers posed by weeds and pest animals to Australia’s natural environment under climate change.
Below you’ll find a list of the stories in our second edition, we hope you find them both interesting and useful. We’ve also introducing a new section called Dig it, which will focus on earlier science published about the issues surrounding invasive species and climate change.
You’ll know you’ve hit a “dig it” story because it will carry the Dig it logo!
Carol Booth, Invasive Species Council Project Officer
Some of Australia’s weeds and pest animals could turn into climate change “super invaders” if we continue to import new strains of already established invasive species.
One big danger in bringing new forms of established invasive species into the country is the risk of arming weeds and pest animals with the genetic variability needed to quickly adapt to changing conditions under climate change.
Environment groups from across Australia have joined forces to launch the Stop Invasive Species Alliance, a coalition of 17 conservation groups calling on the Federal Government to usher in reforms equal to protecting the country’s environment from invasive species threats.
The alliance says invasive species are one of the top threats to global biodiversity and have been the number one cause of animal extinctions in Australia.
The increasing fire risk for southeast Australia under climate change has, not surprisingly, become a hot topic. But most of the popular discussion of the Victorian fires and climate change has ignored the issue of how weeds can greatly influence fire risk.
Recent research in Alaska by Philip Higuera, from the University of Washington, and colleagues has demonstrated that vegetation can substantially alter the direct effects of climate change on fire regimes.
An introduced pasture grass planted as livestock feed in arid and semi-arid Australia is one of several weedy invaders being blamed for an increase in unnatural wildfires across American deserts and national parks.
Speaking during an investigation into the impacts of climate change on America’s national parks Thomas Swetnam, a professor of dendrochronology from the University of Arizona, warned that buffel grass is one of several invasive grass species fuelling increasingly hot desert wildfires that are wiping out cactus and other native species in the US.
The invasive frog-killing pathogen chytrid fungus (Batrachochytrium dendrobatidis) kills some amphibians by compromising their growth rather than killing them directly, new research from Spain has found.
Trenton Garner, of the Zoological Society of London, and colleagues found that common toads (Alytes obstetricans) died after exposure to the chytrid fungus even when there was no detectable infection at the time of death.
The University of Sydney’s Richard Russell has contested claims that climate change will greatly increase mosquito-borne diseases in Australia.
The professor of medical entomology says the claims, based on the impacts of rising temperatures, fail to adequately consider other implications of climate change and factors about the diseases, how they are spread and the ability of health services to deal with new infections.
Increasingly warmer oceans could kickstart a dramatic shift in global marine diversity by fast-tracking the dominance of our seas by invasive alien species and accelerating the loss of biodiversity.
That warning is one of many dire predictions made by the Secretariat of the UN’s Convention on Biological Diversity ahead of this year’s International Day for Biological Diversity, which will be held on May 22 to highlight the damage being done to the world’s ecosystems and human wellbeing by invasive species.
Southeastern and southwestern Australia will be hardest hit by new weeds, according to climate change modelling undertaken by the CSIRO.
John Scott and co-workers have modelled the potential distribution of 41 sleeper/alert weeds (species that have naturalised but not spread widely) in Australia under various climate change scenarios to predict which species would be favoured.
Bacterial infections causing a devastating disease killing off corals in the Caribbean, and more recently the Pacific, have been linked to global warming.
James Cervino, a professor at Pace University and research scientist at Woods Hole Oceanographic Institute, and co-workers have identified a group of four new vibrio bacteria that combine with existing vibrio to attack zooxanthellae (algae that function as photosynthetic symbionts for coral). If their zooxanthellae die, the corals starve.
Climate change has stimulated demand for models of how changing weather patterns will affect the distribution of both native and exotic species.
But a 2007 research paper finds that predictions for invasive species based on the climatic conditions in their native ranges are apt to be wrong.
A study of sea squirts (ascidians) shows that increasing water temperatures could favour invasive forms by helping them outcompete native populations of these marine invertebrates.
In work conducted from 1991 to 2001, John Stachowicz, from the University of California, and colleagues compared the colonisation of tiles by native and introduced sea squirts at a study site in southern New England (US) where mean annual ocean surface temperatures had increased over the previous quarter-century.
The role global shipping plays in spreading microorganisms (including a toxic algae that causes frequent closures of Tasmanian aquaculture farms) has come under the spotlight of researchers analysing ballast water flowing into the lower Chesapeake Bay in the US.
And although Lisa Drake from the US Coast Guard Academy and her team have not focused on climate change they note that rising sea temperatures are likely to see tropical micro-ogranisms, including pathogens, expand their distribution.
Climate change and invasive species are major drivers of change in marine environments, implicated in the decline and even collapse of several ecosystems.
In her review of marine invasions and climate change, Anna Occhipinti-Ambrogi, from the Universita` degli Studi di Pavia, highlights examples from the Mediterranean, where warming is regarded as particularly important in the establishment of alien species.
The plants and animals that make their home in the world’s alpine ecosystems are some of the most threatened by climate change.
Unlike other regions, where species can migrate to escape warmer temperatures, plants and animals living at higher altitudes are often at the top of their range, and have nowhere to go if they are to survive climate change.
An important 2008 CSIRO review of the impacts of climate change on Australia’s national reserve system highlighted interactions with invasive species.
Authors Michael Dunlop and Peter Brown noted that exotic species are one of the reasons future climate change will be unlike any experienced previously.
Jessica Hellman, from the University of Notre Dame, and colleagues have identified five categories of interactions between climate change and invasive species, operating at different stages of the “invasion pathway”.