If you’re worried about bushfires but want to keep your leafy garden, follow these tips

Shutterstock/autau

Philip Gibbons, Australian National University and Geoff Cary, Australian National University

As we witnessed last summer, the number of houses destroyed during bushfires in Australia has not been stemmed by advances in weather forecasting, building design and the increased use of large water-bombing aircraft.

At the latest count, more than 3,500 homes were destroyed the summer just gone, which makes this the most destructive bushfire season in Australia’s history.

The principal reason for the continually high rate of destruction is that so many homes are being built close to bushland. An estimated 85% of all houses destroyed in bushfires in Australia are within 100m of the bush.

It follows that clearing vegetation around houses is at the forefront of advice provided by fire authorities to homeowners in bushfire-prone areas.

A home without trees and shrubs around it is the safest option during a bushfire. But realistically, many people will want to retain some vegetation. And there are ways to do this sensibly.

Is clearing bushland the solution?

Research shows houses close to bushland are more effectively protected by clearing trees and shrubs within approximately 40m of the home.

There are laws in most states and territories, such as New South Wales’ 10/50 Vegetation Clearing Scheme, that permit this to some extent.

But if all homeowners in bushfire-prone areas exercised their right to clear trees and shrubs, places such as the Blue Mountains, Perth Hills, Mount Lofty Ranges, Dandenongs and our coastal towns like Mallacoota, Margaret River and Batemans Bay would be vastly different in character.

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Residents and tourists are attracted to these areas for the aesthetics, privacy, wildlife and shade native trees and shrubs provide.

A study of rural-residential areas north of Melbourne found property values were higher where there was a considerable cover of native vegetation. We not only like our native bush, we are prepared to pay for it.

Because many people value trees and shrubs around their homes, it is not realistic to expect uniformly low fuel loads within bushfire-prone parts of Australia.

Can we have our cake and eat it?

We analysed data collected before and after the 2009 Black Saturday Fires, in which 2,133 houses were destroyed.

We found that the extent of “greenness” of vegetation surrounding homes had a bearing on whether the structure withstood fire.

Greenness refers to the extent to which plants are actively growing. Houses with trees and shrubs within 40m were slightly less likely to be destroyed if the vegetation had relatively high values of “greenness”, as compared to houses surrounded by vegetation with low greenness value.

This makes sense because greener vegetation, typically with higher moisture content, has lower flammability, requires more energy to ignite and therefore can reduce the intensity of a fire.

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Thus, watering your garden through summer, if this is feasible, or choosing plants with high moisture content (such as succulents) may reduce the bushfire risk compared with the same amount of vegetation with a lower moisture content.

We also found the risk to houses during bushfire was slightly less where trees and shrubs within 40m were not continuous, but instead arranged as discrete patches separated by a ground layer with low fuel hazard, such as mown grass.

As trees and shrubs become less continuous the heat transfer between patches becomes less efficient and the intensity of the fire is likely to decline.

Provided bushfires in your area come from a predictable direction, retaining more trees and shrubs downwind of this direction from your house poses less risk than the same cover of trees and shrubs retained upwind from your house.

This makes sense because burning embers, which are the main cause of house losses during bushfires, travel in the direction of the wind.

You can’t eliminate risk from bushfires

We must emphasise that while these strategies can strike a balance between retaining trees and shrubs and preparing for bushfires, they will not guarantee your home will survive a bushfire – especially in severe fire weather.

So in addition to vegetation management, other strategies – such as building design, adequate insurance and evacuating early to a safer place – should be considered in every household’s bushfire planning.

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Read more:
12 simple ways you can reduce bushfire risk to older homes

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Philip Gibbons, Professor, Australian National University and Geoff Cary, Associate Professor, Bushfire Science, Fenner School of Environment and Society, Australian National University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

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The phoenix factor: what home gardeners can learn from nature’s rebirth after fire

Kingsley Dixon, Curtin University

A startling phenomenon occurs after a bushfire tears through a landscape. From the blackened soil springs an extraordinary natural revival – synchronised germination that carpets the landscape in flowers and colour.

So what is it in bushfires that gives plants this kiss of life? The answer is smoke, and it is increasingly transforming everything from large-scale land regeneration to nurseries and home gardening.

The mystery of seed germination

Burnt plants survive bushfires in various ways. Some are protected by woody rootstocks and bark-coated stems; others resprout from underground buds. But most plants awaken their soil seed bank, which may have lain dormant for decades, or even a century.

However, this smoke-induced seed germination is not easily replicated by humans trying to grow the plants themselves. Traditionally, many native Australian flora species – from fringe-lilies to flannel flowers and trigger plants – could not be grown easily or at all from seed.

The fringe-lily, the seed of which has been found to germinate after smoke treatment.
Flickr

In recent decades this has meant the plants were absent from restoration programs and home gardens, reducing biodiversity.

In 1989, South African botanist and double-PhD Dr Johannes de Lange grappled with a similar conundrum. He was trying to save the critically rare Audonia capitata, which was down to a handful of plants growing around Cape Town. The seed he collected could not be germinated, even after heat and ash treatments from fire. Extinction looked inevitable.

But during a small experimental fire, a wind change enveloped de Langer in thick
smoke. With watering eyes, he realised that smoke might be the mysterious phoenix factor that would coax the seeds to life. By 1990 he had shown puffing smoke onto soil germinated his rare species in astonishing numbers.

The technique is simple. Create a smouldering fire of dry and green leafy material and pass the smoke into an enclosed area where seed has been sown into seed trays or spread as a thin layer. Leave for one hour and water sparingly for ten days to prevent the smoke from washing out of the seed mix. The rest is up to nature.

Diagram showing the various ways that smoke is applied to seeds.
Supplied by Simone Pedrini

Taking smoke germination to the world

Soon after the de Lange discovery, I visited the Kirstenbosch National Botanic Garden in Cape Town. I was shown a few trays of seedlings out the back – some from seeds treated with smoke, some without. The difference was stark. Smoke-treated seeds produced a riot of green, compared to others that resulted in sparse, straggling seedlings.

A tray of seedlings where seed was treated with smoke, left, compared to a non-treated tray.
Supplied by author

But was smoke just an isolated African phenomenon, I wondered? Would 150 years of frustrated efforts to germinate some of Australia’s most spectacular and colourful species – from grevillea and fan-flowers to rare native heaths – also be transformed by smoke?

At first, the answer appeared to be no, as every attempt with Australian wildflower seed failed. But after many trials, which I oversaw as Director of Science at the Western Australian Botanic Garden, success came in 1993. Extra time in the smoke house and a serendipitous failure in the automated watering system resulted in the germination of 25 different species with seedlings. Some were thought to have never been germinated by humans before, such as wild-picked yellow bells (Geleznowia verrucosa) or the giant feather rush (Loxocarya gigas).

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This discovery meant for the first time smoke could be used for difficult-to-germinate species for the home gardener and cut flower growers. These days more than 400 species of native seeds, and potentially more than 1,000, respond to smoke treatment. They include kangaroo paw, cotton-tails, spinifex, native bush food tomatoes and fragrant boronias.

Highway plantings, mine site restoration and, importantly, efforts to save threatened plant species now also benefit greatly from the smoke germination technique. For example, smoke houses are now a regular part of many nurseries, which also purchase smoke water to soak seeds for sowing later.

Kangaroo paw seeds respond well to smoke treatment.
Supplied by the author

In mine site restoration, direct application of smoke to seeds dramatically improves germination performance. This translates into multimillion-dollar savings in the cost of seed.

Smoke is also a powerful research tool used to audit native soil seed banks, which includes demonstrating the adverse affects of prescribed burning in winter and spring on native species survival.

Collaboration with research groups in the US, China, Europe and South America has expanded the use of smoke to germinate similarly stubborn seed around the world.

So what is smoke’s secret ingredient?

In 2013, an Australian research team made a breakthrough in determining which of the 4,000 chemicals in a puff of smoke resulted in such starting germination. They patented the chemical and published the discovery in the journal Science.

The smoke chemical, part of the butenolide group of molecules, was named karrikinolide, inspired by the local Indigenous Noongar word for smoke, karrik.

Karrikinolide is no shrinking violet of a molecule: just half a teaspoon is enough to germinate a hectare of bushland, which equates to 20 million seeds.

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How the land recovers from wildfires – an expert’s view

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Smoke is sold to home gardeners and for commercial use in the form of smoke water, smoke-impregnated disks, or smoke granules. All contain the magical karrikinolide molecule.

Why not try it at home?

Home gardeners can try smoking their own seeds – but what you burn matters. Wood smoke can be toxic to seeds. Making your own smoke from leafy material and dry straw ensures you have the right combustible materials for germination.

At least 400 native seed species, and possibly up to 1,000, have been found to respond to smoke treatment.
Supplied by author

For the home gardener, having a bottle of smoke water on hand or constructing your own smokehouse can make all the difference to germinating many species – including those stubborn parsley seeds. To find out more, a webinar at this link shows you how to use smoke and even construct your own smoke apparatus.

Kingsley Dixon, John Curtin Distinguished Professor, Curtin University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Old man’s beard is a star climber for Australian gardens

John Tann/Flickr, CC BY-SA

Gregory Moore, University of Melbourne

Sign up to Beating Around the Bush, a series that profiles native plants: part gardening column, part dispatches from country, entirely Australian.

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Clematis aristata is a gem of a native climbing plant. Commonly known as Australian clematis, goatsbeard or old man’s beard, these names and the species name aristata (Latin for bearded) all refer to the bristle-like appendages to the fruit.

Although there are more than 300 Clematis species worldwide, only six are native to Australia. Old man’s beard’s flowers are a little more modest than its cousins.

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Clematis aristata is widely distributed in southeastern Australia and has been recorded in all of the eastern mainland states, as well as in Tasmania and South Australia. There is a record of it in Western Australia from around a century ago, but this has not been confirmed in recent times.

With such a wide natural range, it is not surprising that in occurs in many different habitats and soil types. Herein lies one of the great attributes of C. aristata: it has many local forms and is easy to propagate and grow in almost any climate or soil type.

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The Conversation, CC BY

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Its flowers are white or cream-coloured, and while they are only 2-3cm across they occur in such great numbers they make a fine show. As a climber, they do have the capacity to smother a host, but more often than not the two plants live long lives together without doing harm. In the garden, with a little careful management and pruning, old man’s beard can grow for decades without causing problems while putting on a fine floral display each spring.

One of the wonders of seeing old man’s beard in it natural habitat is the diverse places and spaces it occupies. In the tall wet forests of the east coast you can see it flowering high in the canopies of 60-metre eucalypts, but on the clays of the windswept basalt plains, it appears as flowering orb growing over a shrubby acacia or grevillea. You can also find it growing on an old fence, a rocky outcrop, or simply growing as a scrambler.

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In some parts of Australia, the roots of the species were used as a food source by Indigeneous communities. Its sinuous branches were used like string or laces by some early settlers, and it is hard to imagine that Indigenous people did not use it in this way on some occasions. However, it breaks easily and becomes quite brittle as it dries, and so is useful only in short lengths and for short periods.

It is easy to propagate from seed, and in some places it self-seeds readily and young seedlings can be dug up and grown on with good success rates. It can also be grown from semi-hardwood cuttings in a good propagating mix and a little shelter. You may have heard old man’s beard likes cool roots, good sun and moist soil, but this depends on where you source your plants and seeds.

Clematis aristata growing in Werribee Gorge State Park, Victoria.
Rexness/Flickr, CC BY-SA

Different populations of old man’s beard have adapted to their local environments and so it is always worth getting your plants and seeds from your local native nursery.

The old man’s beard from the temperate forest of the east coast does not do well on the basalt plains, but then again the plants from the basalt plains do not grow well on good soils in cooler, rainy sites. One of the joys of working with old man’s beard is that if you use locally indigenous plants, they will grow quickly without the need for much care and they are usually free of pests and disease. In the poorly structured clay soils of the great basalt plain, with the annual rainfall often below 600mm, it is amazing to see it grow so well without the need for irrigation.

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Like most plants, if you are growing old man’s beard in garden beds it will benefit from a 75-100mm layer of organic mulch containing both fine and coarse material – a mix of native plant leaf litter and twigs will do nicely. Once they have flowered, they can look a bit untidy and some people do not like the look of the bristly fruits as they dry, so a bit of light pruning can be beneficial. Annual pruning will also keep old man’s beard growing where you want it and ensure it is not causing problems to other plants in your garden.

So if you want a native climbing plant that will give you years of spectacular and worry-free flowering, give C. aristata some thought. All you have to do is get hold of a locally growing variant, plant it, and step back before it starts growing over you!

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Sign up to Beating Around the Bush, a series that profiles native plants: part gardening column, part dispatches from country, entirely Australian.. Read previous instalments here.

Gregory Moore, Doctor of Botany, University of Melbourne

This article is republished from The Conversation under a Creative Commons license. Read the original article.

How the Wardian case revolutionised the plant trade – and Australian gardens

Melburnians admire the first primrose to arrive in the colony, transported by a Wardian case, in Edward Hopley’s A Primrose from England, circa 1855.
Bendigo Art Gallery, Gift of Mr and Mrs Leonard Lansell 1964.

Luke Keogh, Deakin University

The first journey of a Wardian case was an experiment. In 1829, the surgeon and amateur naturalist Nathanial Bagshaw Ward accidentally discovered that plants enclosed in airtight glass cases can survive for long periods without watering. Four years later he decided to test his invention by transporting two of his cases filled with a selection of ferns, mosses and grasses from London to Sydney, the longest sea journey then known.

On November 23 1833, Ward received a letter from Charles Mallard, the ship captain responsible for the two cases, telling him: “your experiment for the preservation of plants alive … has fully succeeded”.

Gleichenia microphylla.
Krzysztof Ziarnek, Kenraiz/Wikimedia Commons, CC BY

The next challenge was the return journey. In February 1834, the cases were replanted with specimens from Australia. Eight months later, when Ward and friend George Loddiges, a well-known nurseryman, went aboard the ship in London they inspected the healthy fronds of a delicate coral fern (Gleichenia microphylla), an Australian plant never before seen in Britain. The experiment was a success.

The Wardian case, as it would become known, revolutionised the movement of live plants around the globe. They were shaped like a miniature greenhouse, made of timber and had glass inserts in the roof. In the cases, plants had a greater chance of survival when in transit.

Wardian cases full of cycads from Rockhampton, Queensland, arrive at the Missouri Botanic Gardens after a long journey via London and New York, c.1920.
Missouri Botanic Gardens.

Often thought of as only a product of the gardening crazes of the Victorian era, the Wardian case was actually a notorious prime mover of plants. Some of the key uses of the case include moving tea from China to India to lay the foundations of the Assam and Darjeeling tea districts; helping move rubber from Brazil and transporting it via London to Asia, which is now the leading producer of the crop; and repeatedly moving bananas over many decades to the Pacific Islands, Central America and the Caribbean.

A tea plantation in India: the cases moved tea from China to India to lay the foundations of the Assam and Darjeeling tea districts.
Wikimedia Commons

The Wardian case resolved a major bottleneck in the transport of live plant species, but it also had major consequences for environmental relationships in the 19th and 20th centuries.

An untold story

Botanists and horticulturalists used this simple box for over a century to carry hundreds of thousands of plants around the globe, whether they were in England or the United States, France or India, Russia or Japan. The Australian story of the Wardian case is an important and untold one.

Wardian cases line the paths at the Adelaide Botanic Gardens.
Adelaide Botanic Gardens.

Each state has an important connection to it. New South Wales received the first plants from Ward himself. The Royal Botanic Gardens, Kew, sent its first Wardian cases, full of fruit trees and ornamental plants, to Western Australia. The Adelaide Botanic Gardens even had a path lined with Wardian cases. Tasmania was vital in the 19th-century fern trade. And Queensland used the Wardian case to transport the cactoblastis moth to help solve the prickly pear infestation.

Victoria’s connection to the case is unsurprisingly one of gardeners and ornamental plants. Today, Victoria is home to Australia’s largest nursery industry, by some reports worth more than $1.6 billion annually and employing more than 11,000 people. The industry today cannot be separated from the long global history of moving beautiful and useful plants to Australia more than a century ago. Two examples illuminate the thriving early trade in Victoria.

Preparing to send live plants in Wardian cases at the Jardin d’Agronomie Tropicale, Paris, c.1910.
Image courtesy Bibliothèque historique du CIRAD.

Published in 1855, Charles Mackay’s widely circulated poem The Primrose was about the landing in Melbourne of a beautiful rare flower and the procession from the docks to an exhibition location in the city. It read, in part:
“She has cross’d the stormy ocean/A pilgrim, to our shore/As fresh as Youth and Beauty/And dear as days of yore.”

By some reports, more than 3,000 people turned out to see the floral traveller. Police were called in to restore order to Melbourne’s streets during the procession. News of the fanfare was carried in major international newspapers including Harper’s Weekly and the Illustrated London News.

The British artist Edward Hopley painted the scene, A Primrose from England (1855), to memorialise both the moment of the plant arriving in Melbourne and, in typical Hopley style, the social milieu of the period.

The technology for moving the plant was not lost on either artist. The primrose that Mackay so eloquently lyricised and Hopley so captivatingly brought to life arrived in Melbourne in a specially designed Wardian case. It would not have arrived without this technology for moving plants. It was not just the primrose. In the decades following 1858, the Wardian case played a major role in shaping the aesthetics and species available in the Victorian landscape.

Melbourne, the Garden Capital of Victoria, Australia, by James Northfield.
State Library Victoria.

In early April 1862, three decades after Ward’s invention, the well-known Victorian nurseryman Thomas Lang delivered a lecture to the Ballarat Horticultural society titled “On Wardian, or Plant Cases”. Lang began by describing his first encounter with the cases in Edinburgh. He went on to detail the many useful plants, such as the giant Californian redwood, that he had introduced with the help of the case. By his own estimate, Lang transported nearly a million plants to Victoria in just one decade in the late 19th century, a staggering number by just one nurseryman.

Californian redwoods in Victoria’s Great Otway National Park.
Shutterstock

Now living in regional Victoria, after many years of travel researching a book on the Wardian case, I often think about Lang and the enthusiasm colonists had for bringing over beautiful plants. Lang proclaimed in his lecture of 1862: “The comfort, the pleasures, the commercial interests, the happiness of mankind are promoted by the use of Wardian cases.”

To move beautiful ornamental plants here was very much part of the home-making process for colonists.

But it was always a trade. While beautiful plants came into Australia, many useful ones went out. Often we forget that the beauty of our gardens is as much about moving plants, as it is about the hard work of tilling the soil.

Next time your hands are covered in soil, it might be good to wonder where that camellia or fuchsia or rose or apple or kiwi fruit or lemon originated – chances are it travelled in a Wardian case.

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Luke Keogh’s book The Wardian Case will be published next year by the University of Chicago Press. He delivers the Redmond Barry Fellowship Presentation at the University of Melbourne on July 25 2018.

Luke Keogh, Visiting Scholar, Deakin University

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

The secret agents protecting our crops and gardens

Lacewings are fantastic predators and are easy to rear and release.
Dan Papacek & Tony Meredith (Bugs for Bugs), Author provided

Lizzy Lowe, Macquarie University and Manu Saunders, University of New England

Insect pests cause a huge amount of damage to crops globally. In Australia alone, pests are responsible for around A$360 million of crop losses a year. Controlling pest outbreaks is crucial for food security and human health. Since the 1940s, our primary defence against crop pests has been synthetic pesticides. But using pesticides comes at a huge cost.

Not all bugs are bad!

Bees, flies and butterflies help to pollinate our plants. Decomposers like beetles and worms help break down wastes and return nutrients to the soil. Meanwhile, predators and parasites help control the species that are pests. One of the biggest environmental problems with pesticides is that they can affect these beneficial species as well as the pests they’re targeting.

Predatory insects and spiders control pests with none of the health and environmental risks of chemicals. So when we kill these species with insecticides, we are shooting ourselves in the foot.

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Losing insects also has flow-on effects for larger animals that rely on them for food. Because invertebrates have such important roles to play in our environment, losing them to insecticides can completely change how ecosystems function.

An alternative to insecticides

Biological control (or biocontrol) relies on “secret agents” – the natural enemies (predators and parasitoids) of pests that live freely in the ecosystems around us.

There is a huge range of predatory invertebrates that eat pests. They include dragonflies, preying mantids, beetles (including ladybugs), lacewings, spiders, mites, wasps, and even some flies.

Parasitoids, meanwhile, are insects that lay their eggs in the bodies of other invertebrates. Their larvae extract nutrients from the host during their development, which ultimately kills the host. Wasps are best known for this strategy but there are also parasitoid flies and beetles.

Lady birds are voracious predators ready to eat pests in crops and gardens.
Manu Saunders

Predators and parasitoids are useful because they use pest insects, like caterpillars and aphids, as food to reproduce and grow their populations. We walk past many of these hard working agents every day without knowing it.

One biocontrol method that gardeners and land managers use is called augmentation. This simply means raising lots of live individuals of particular natural enemies, like ladybirds or wasps, and releasing them into an area to control pests.

Alternatively, gardeners might change the local environment to encourage these natural enemies to move in on their own. They might include natural insectariums or planting different types of vegetation to encourage diverse invertebrate communities. There is increasing evidence of the success of these strategies in organic farming so we should be thinking about using them more broadly.

Selecting your insects

If you want to release biocontrol agents, you need to choose them carefully, just like human special agents. Like any introduced plant or animal, there is a risk that good bugs could become pests (if they feed on the wrong insects, for example).

Selecting biological control agents requires close collaboration between managers, skilled entomologists and other scientists. For each new species, they identify the pest and some potential predators. They look at the predator’s life cycle and resource needs, and consider how it interacts not just with pests, but with other insects too. If agents are coming in from overseas, they also need to be cleared by government biosecurity.

Parasiotid wasps, lacewings, predatory mites, ladybird beetles, and nematodes are all common biocontrol agents. These species are relatively easy to raise in large numbers and work well when released into the field. Spiders are also a really important predator of many pest insects, but they’re often overlooked in the biocontrol game because they are harder to breed – and for some reason people don’t always like releasing large numbers of spiders.

Many biocontrol agents are enemies of pests in general, preying on aphids, caterpillars and fruit flies alike. It’s important to have generalists around for every day pest control, but sometimes a more targeted approach is needed. This is when specialised predators or parasitoids come in. These are species that only target specific pests like leaf miners, beetles, scale insects or spider mites. This way the target pest can be managed with no risk of the parasitoids accidentally attacking other beneficial invertebrates.

Raising good bugs

It’s very exciting to get live insects in the mail!
Lizzy Lowe

Once a biocontrol agent has been selected, greenhouses or lab facilities start raising a large population. This is an emerging market in Australia, but there are already a number of companies in Australia who specialise in rearing biological control agents.

This is a tricky job because demand for the product is variable and is not easy to predict. Warmer seasons are the peak time for most pests, but problems can arise at any time of the year. In most cases the biocontrol company will maintain breeding colonies throughout the year and will be ready to ramp up production at a moment’s notice when a farmer identifies a pest problem. Each company usually provides 10-20 different biocontrol agents and are always looking for new species that might be useful.

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When it comes to getting the agents to the farmers, the bugs can be shipped as eggs (ready to hatch on arrival), or as live adults ready to disperse and lay their own eggs. The packages are express posted in boxes designed to keep the insects cool and safe.

Once the farmer or natural resource manager receives the bugs, applying them is quite simple. The secret agents are released among the crops, usually by hand, but in some special cases they may be airlifted in via specialised drones!

Drones can be used to deploy biological control agents.
Nathan Roy (Aerobugs)

It’s important to monitor the pests and the biological control agents after release to check that the agents are working. Some farmers are happy to do this themselves but most biological control companies have experts to visit the farms and keep an eye on all parties.

Can I use good bugs in my garden?

If you have a problem with a pest like aphids it is possible to buy predators such as ladybirds or lacewings to quickly deal with the problem. But for long term pest control, there are probably already some natural enemies living in your garden! The easiest and cheapest way to help them is to put the insecticides away and ensure your garden is a friendly environment for secret agents.

Lizzy Lowe, Postdoctoral researcher, Macquarie University and Manu Saunders, Research fellow, University of New England

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

Stop the miners: you can help Australia’s birds by planting native gardens

Kathryn Teare Ada Lambert, University of New England

Some Australian birds are pushing out other species, and even damaging trees. Noisy and bell miners are two of Australia’s most aggressive bird species. Found throughout eastern Australia, in recent years their numbers have increased at the expense of our smaller birds.

Both species are spreading to new areas, largely due to human destruction of habitat. Noisy miners are able to invade areas where habitat has been modified, particularly gardens.

Bell miners, meanwhile, can invade areas that have invasions of weeds in the understorey such as blackberry and lantana that they use for nesting.

The good news is we can help stop the spread of these birds, by putting native plants in our gardens.

Masked mobster: noisy miners are increasing in number and spreading at the expense of smaller birds.
Kathryn Lambert, Author provided

Good birds gone bad

Both species of these miners (genus Manorina) have been found to reduce bird diversity through their aggressive behaviour, and have been associated with eucalypt dieback.

Human disturbance has been linked to increasing numbers of noisy miners. One study in the box-ironbark forests of southeast Australia, found that noisy miners an move into areas of smaller fragments and unhealthy trees.

They then chase away other birds, reducing the number of species and potentially having knock-on effects on ecosystems. The problem is so serious that noisy miners are listed as a national threatening process.

More research is needed to find out why bell miners are becoming more common. But our research has found that bell miners show similar behaviour to noisy miners. They have a distinctive call that travels for tens of metres through the forest.

Bell miners cause Bell Miner Associated Dieback in trees. It is thought that their feeding and breeding behaviours lead to the death of eucalypts on the east coast of Australia. They also take over habitat that would be used by other birds.

Bell miners are known for their loud calls.
Sascha Wenninger/Flickr, CC BY-SA

Are the birds to blame?

Where miners are normally found in lower numbers, disturbances by people can tip the balance in their favour. This includes increasing noise levels, removing corridors of connecting native vegetation, creating gardens with exotic plants, building cities, houses, parks, logging and introducing invasive species that create thick understories.

These disturbances increase the habitat available for these two species, allowing them to increase in number and drive out the smaller birds that compete for their food sources.

Noisy miners particularly favour open areas that don’t have thickets of shrubs of smaller trees underneath the canopy. Conversely, bell miners prefer thick understoreys, particularly those create by introduced weeds such as lantana.

So if we are causing these birds to increase in number, how can we reduce their numbers and re-create the original habitat where all species could co-exist?

Build a bird-friendly garden

You need to create a multi-layered habitat of ground covers, small and medium shrubs, and trees that provide food and shelter locations all year for a variety of species.

These plant species need to have diverse structures, and should be close together to form dense, protective thickets, including climbers within medium-to-tall shrubs and trees, nectar-bearing and seed-bearing plants. Mulch can also encourage insect life for insectivorous birds.

Plants should also be local species that grow naturally in the area and are suited to the climate. Native birds that live in the area will then visit your garden as another food source in their territory.

A bird-friendly garden.
Karthryn Lambert, Author provided

Reducing weeds in your garden and neighbouring bushland (many weeds are derived from garden plants) can help native species. General natives can also be planted if you can’t find local natives in your local nursery.

Even in gardens where noisy miners dominate, smaller birds can survive in a dense understorey.

Meanwhile, a thin midstorey with fewer leaves may help to reduce bell miner abundance, as suggested by our recent study near Kyogle, New South Wales.

You should also consider the timing of flower and fruit production, to ensure that there is always food available for birds. You should also remove fruiting plants such as cotoneaster and blackberry that attract predators such as currawongs, to help reduce predation on smaller bird species.

Using chemical-free weed and pest control and mulching garden waste can also increase the food available for birds.

Lawns can also be replaced with native grasses that produce seed to attract finches and other seed-eaters such as crimson rosellas. Birds also need fresh water, which you can provide with a pond or bird bath. This should be placed within vegetation to ensure birds feel safe from predators.

Why are native gardens important?

Local biodiversity can be maintained by native gardens, ensuring long-term ecological sustainability. Small birds and other wildlife benefit from planting native species.

Many species are negatively affected by the current structure of gardens such as lawns, few scattered trees and the placement of concrete and houses without any access to nesting habitat.

Gardening in Australia needs to be changed to favour more native species and provide structure on a landscape scale that includes a variety of gardens.

Kathryn Teare Ada Lambert, Research Associate, University of New England

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

USA: Climate Change Rooftop Farmers

The link below is to an article on climate change in the USA and how urban dwellers are planting rooftop gardens in response.

For more visit:
http://tv.msnbc.com/2013/02/23/urbanites-combat-climate-change-with-rooftop-farms/

Hunter Region Botanic Gardens

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ABOVE: The Southern Wetlands Boardwalk – Hunter Region Botanic Gardens

Late last week I decided I should do something with the final day of my annual leave that I had taken this time round, so I thought I’d pop into the Hunter Region Botanic Gardens near Raymond Terrace in New South Wales, Australia. I had been here before, but that was a long time ago. I wasn’t impressed on that first visit, so after more then a decade had it improved? Well that was the question I was keen to answer.

ABOVE: The Rotunda  BELOW: Succulents Section

There was a $4.00 ‘escape’ fee, which would allow a token to be purchased and then the boom gate would rise once it was placed into the proper slot at the exit. So no entrance fee, just an exit fee. I was willing to pay this for a quick look and…

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Birds: Feeding Birds not a Good Thing?

Many people love to have native birds visit their gardens. To achieve this we feed birds in a variety of ways. Feeding wild birds does have consequences for the long term survival of the birds being fed. The following link is to an article with more on this subject.

For more visit:
http://www.nwf.org/News-and-Magazines/National-Wildlife/Birds/Archives/2011/Effects-of-Bird-Feeding.aspx

 

Dharug National Park: Myrtle Rust Brings Closure of the Mill Creek Camping Area

The introduced fungal infection ‘Myrtle Rust’ has spread from gardens and nurseries into the Dharug National Park. The Mill Creek Camping Area has been temporarily closed in consequence of the spread, with National Park and Wildlife Service staff carrying our control measures during the closure in an attempt to prevent any further spread of the disease.

For more information see:

http://www.environment.nsw.gov.au/media/DecMedia10112604.htm