How Australia’s animals and plants are changing to keep up with the climate



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Flora and fauna can adapt to climate change, but some are more successful than others.
allstars/shutterstock

Ary Hoffmann, University of Melbourne

Climate change is one of the greatest threats facing Australia’s wildlife, plants and ecosystems, a point driven home by two consecutive years of mass coral bleaching on the Great Barrier Reef. The Conversation

Yet among this growing destruction there is a degree of resilience to climate change, as Australian animals and plants evolve and adapt.

Some of this resilience is genetic, at the DNA level. Natural selection favours forms of genes that help organisms withstand hotter and drier conditions more effectively.

Over time, the environmental selection for certain forms of genes over others leads to genetic changes. These genetic changes can be complex, involving many genes interacting together, but they are sufficient to make organisms highly tolerant to extreme conditions.

Some of this resilience is unrelated to DNA. These are “plastic” changes – temporary changes in organisms’ physical and biochemical functions that help them deal with adverse conditions or shifts in the timing of environmental events.

Plastic changes occur more quickly than genetic changes but are not permanent – the organisms return to their previous state once the environment shifts back. These changes also may not be enough to protect organisms from even more extreme climates.

What about Australia?

In Australia there is evidence of both genetic and plastic adaptation.

Some of the first evidence of genetic adaptation under climate change have been in vinegar flies on the east coast of Australia. These flies have a gene that encodes the enzyme alcohol dehydrogenase. This gene has two major forms: the tropical form and the temperate form. Over the past 30 years, the tropical form of the gene has become more common at the expense of the temperate one.

Plastic adaptation due to climate change has been demonstrated in common brown butterflies in southern Australia. Female butterflies are emerging from their cocoons earlier as higher temperatures have been speeding up their growth and development by 1.6 days every decade. According to overseas research, this faster development allows butterfly caterpillars to take advantage of earlier plant growth.

Higher temperatures are causing the common brown butterflies in southern Australia to come out of their cocoons earlier.
John Tann/Wikimedia Commons, CC BY-SA

In many cases, it is not clear if the adaptation is genetic or plastic.

The average body size of Australian birds has changed over the the past 100 years. Usually, when comparing birds of the same species, birds from the tropics are smaller than those from temperate areas. In several widespread species, however, the birds from temperate areas have recently become smaller. This might be the direct result of environmental changes or a consequence of natural selection on the genes that affect size.

In the case of long-lived species like eucalypts, it is hard to see any adaptive changes. However, there is evidence from experimental plots that eucalypts have the potential to adapt.

Different eucalypt species from across Australia were planted together in experimental forestry plots located in various environments. These plots have unwittingly become climate change adaptation experiments. By monitoring the plots, we can identify species that are better at growing and surviving in extreme climatic conditions.

Plot results together with other forms of DNA-based evidence indicate that some trees unexpectedly grow and survive much better, and are therefore likely to survive into the future.

What’s next?

We still have much to learn about the resilience of our flora and fauna.

There will always be species with low resilience or slow adaptive ability. Nevertheless, plastic and genetic changes can provide some resilience, which will change the predictions of likely losses in biodiversity.

Much like how our worst weeds and pests adapted to local climate conditions, as demonstrated many years ago, our local plants and animals will also adapt.

Species with short generation times – a short time between one generation (the parent) and the next (the offspring) – are able to adapt more quickly than species with longer lifespans and generation times.

For species with short generation times, recent models suggest that the ability to adapt may help reduce the impacts of climate change and decrease local extinction rates.

However, species with long generation times and species that cannot easily move to more habitable environments continue to have a high risk of extinction under climate change.

In those cases, management strategies, such as increasing the prevalence of gene forms helpful for surviving extreme conditions and moving species to locations to which they are better adapted, can help species survive.

Unfortunately, this means doing more than simply protecting nature, the hallmark of our biodiversity strategy to date. We need to act quickly to help our animals and plants adapt and survive.

Ary Hoffmann, Professor, School of BioSciences and Bio21 Institute, University of Melbourne

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

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Plastic fantastic: how lotteries could revolutionise recycling



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So many ways to win.
Bignai/Shutterstock.com

Ian A. MacKenzie, The University of Queensland

In July 2018, Queensland will launch a container refund scheme, in a bid to boost recycling and reduce litter and pollution. The Conversation

It will join South Australia, the Northern Territory, New South Wales (later this year) and other places around the world in offering a small refund on all eligible drink containers deposited at designated collection points.

Many of the details have been decided already, including the size of the refund: 10c a bottle.

But is Queensland missing a trick here? Economic evidence suggests that the scheme could be cheaper to run, and boost recycling more, if it was run as a lottery instead, with every recycled bottle representing a “ticket” to a prize draw.

In it to win it

Boosting recycling relies on people changing their behaviour. One of the strongest drivers of behavioural change is economics; that’s why container refund schemes exist at all.

But economists also know that the type and size of this financial reward can have a large bearing on people’s behaviour. For many decades, researchers have focused on working out which rewards prompt the most effort. One key question is whether participants respond better to small, reliable rewards, or to being offered a chance of a big windfall.

Research suggests that contests can be easily designed to incite higher levels of effort than the more humdrum piece-rate rewards. Such contests have already been shown to work well in other environmental contexts, such as allocating pollution permits to companies.

Instead of getting 10c per container, Queenslanders could instead be given an electronic ticket for each container recycled. These tickets – which could perhaps be linked to a householder’s council rates account or other personal identifier – could then be entered into a quarterly lottery. The state government would need to decide on the size and number of prizes, as well as the eligibility rules.

Eyes on the prize

Several benefits are clear. First, there is evidence that it is very easy to incite more recycling using a contest approach.

Lotteries are also more flexible – the prizes can be adjusted relatively easily to increase or decrease participation. If recycling rates are too low, the prize value in the next lottery could be increased. In contrast, adjusting the 10c container refund would be far more difficult once it has already been set up.

The scheme might end up costing less overall, too. As the lottery may have only one prize (or a few), the administrative costs would be minimal compared with a per-unit payment. Depending on the size and number of the prizes, the prize fund could also be smaller than the cost of paying millions of 10c refunds.

Finally, the government can control the geographical placement of container points. This would allow it to influence the number of participants and also the ability to focus on citizens that may have certain preferences for recycling, or risk preferences that enjoy lottery contests. Indeed, research shows that risk attitudes and citizens’ preferences have an important impact on contest outcomes.

Lucky chance

A poorly designed lottery might conceivably work too well – recycling rates might become so high that they overwhelm the infrastructure or cause a glut of recycled materials. This has been shown to be possible when lottery-style contests are used in other environmental regulatory contexts. For example, contests that use pollution reduction as a lottery criterion can be too successful – driving down emissions hugely but at a significant cost to economic output.

Choosing the right-sized prize is crucial. If it’s too small, few people will be enticed to change their behaviour and take part. But if it’s too big, many people might stop using their kerbside recycling facilities altogether, “saving up” their recycling for the lottery. This would present a problem of “additionality”: the scheme would be capturing lots of bottles that would have been recycled anyway.

These are mere details, and the challenges of getting it right shouldn’t stop the Queensland government seriously considering giving the idea a go. It might make recycling a whole lot more exciting.

Ian A. MacKenzie, Senior Lecturer in Economics, The University of Queensland

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