Leek orchids are beautiful, endangered and we have no idea how to grow them

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Marc Freestone/The Conversation

Marc Freestone, Australian National University

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Leek orchids don’t have many friends. Maybe it’s because they lack the drop-dead gorgeous looks of many of their fellow family members. Or perhaps it’s because they’re always the first to leave the party: as soon as sheep or weeds encroach on their territory, they’re out of there. Whatever the reason, you don’t see leek orchids around very often.

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Leek orchids are small, ground-dwelling native Australian orchids, so called for their single spring-onion-like leaf, which shoots up from an underground tuber each autumn. In the spring, if there’s been enough rain, they produce a spike of small brown, green or white flowers.

Like many native orchids, they are battling extinction. My research involves trying to find the secret to propagating them – something we still don’t fully understand.

Marc Freestone/The Conversation


Australia is quite rich in orchids with more than 1,300 native species (by contrast, there are only about 200 species in all of North America). About 140 of these are leek orchids, and most live in bushland remnants across the south of Australia.

With a preference for fertile soils and relatively high rainfall, these little plants suffered severely during the period of agricultural expansion in the southeast of the country during the first half of last century. Rabbits, weeds, inappropriate fire regimes, and declining rainfall patterns continue to plague those that survive, which often hang on in narrow roadsides, beside rail lines or in rural cemeteries – tiny pockets of land that were never ploughed.

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Almost one-third of all leek orchid species are at risk of extinction. Some are already extinct, such as the Lilac Leek-orchid (Prasophyllum colemaniae). It once grew in Melbourne’s outer eastern suburbs, but disappeared when an upgrade of a rail line in the 1970s destroyed the last population. Standing half a metre tall, with fragrant purple-white flowers, it was said to be the most beautiful of all leek orchids.

Collecting seed in the Alpine region.
Marc Freestone

Native orchids are rebounding – but not leek orchids

Fast forward to 2018 and things have changed. The Royal Botanic Gardens Victoria now hosts the largest orchid conservation program in the world. Dozens of critically endangered native orchids from the southeast mainland are being brought back from the brink of extinction through propagation and reintroduction programs.

But not leek orchids.

That’s because we still don’t know how to grow leek orchids successfully. In fact, growing any type of orchid is hard work. For a start, orchid seed is microscopic. It is so small it doesn’t contain any food for the germinating orchid seedling.

Instead, all orchids rely on symbiotic fungi that live in their roots and the surrounding soil and are required to inoculate the orchid seed – the fungus literally pumps food into the seeds to get them to germinate. We have no idea why these fungi do this, but we can replicate this scenario in the lab by carefully extracting fungi from the roots of a wild orchid plant, growing the fungi in a petri dish, and sprinkling in the orchid seed. But for some reason, leek orchid seed rarely germinates, and if it does, the young seedlings usually brown off and die.

Three month old baby leek orchid seedlings. Of the few seeds that germinate, most won’t survive past this point.
Marc Freestone

How to grow leek orchids is the subject of my PhD project with the Australian National University, based at the Royal Botanic Gardens Victoria. We have many theories about what might be going on and we’re looking at seed viability, growing conditions, and the relationship between leek orchids and their symbiotic fungi.

It’s a race against time to work out how to grow them before more species – like the Shelford Leek-orchid (Prasophyllum fosteri) from western Victoria, which is now down to only a handful of wild plants – go extinct.

Why should we care?

At first glance, leek orchids do not appear to be particularly useful for anything. They can’t cure cancer or be traded for Bitcoin. So who cares if they go extinct?

There are only a few hundred coast leek orchids remaining.
Marc Freestone

Well, the first point is we don’t know enough about leek orchids to be able to conclude that they are indeed completely useless to the human race. Second, leek orchids probably used to play an important ecosystem role in the lowland grasslands of southeastern Australia.

Up in the Australian Alps there are several species of leek orchid that are still very common, their flowers providing an important food source for insects. Seeing the massed flowering of the Alpine Leek-orchid (Prasophyllum tadgellianum) in summer really gives you a feel for what the lowland grasslands would have been like once upon a time, when species like the Gaping Leek-orchid (Prasophyllum correctum) would have numbered in the millions. Now there are perhaps 10 plants left.

If it goes extinct, Australia will have lost part of what makes it unique. A small part, perhaps, but when added to all the other threatened species in this country, a significant part.

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Personally, I find leek orchids delicate and utterly defenceless against humans, who have engulfed their world. Ironically, some species are now totally dependent on us for their survival. I feel a great sense of responsibility to help them.

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

Marc Freestone, PhD Candidate, Australian National University

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


How biomethane can help turn gas into a renewable energy source

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Are there greener pastures ahead for gas?

Bernadette McCabe, University of Southern Queensland

Australia’s report card on reducing its greenhouse gas emissions is not exactly glowing, but there are ample opportunities to get it on track during this period of rapid change in the energy sector. Greater use of renewable electricity sources like wind and solar are playing a large part in reducing emissions, and gas can also lift its game.

Gas provides nearly one quarter of Australia’s total energy supply. Around 130,000 commercial businesses rely on gas, and it delivers 44% of Australia’s household energy to more than 6.5 million homes which use natural gas for hot water, domestic heating, or cooking.

Gas has lower greenhouse emissions than most other fuels, and the gas used in power generation has about half the emissions of the current electricity grid.

Even so, natural gas can do more to help Australia meet its carbon-reduction targets.

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An industry document released last year, Gas Vision 2050, explains how new technologies such as biomethane and hydrogen can make that happen, by replacing conventional natural gas with low-emission alternative fuels.

Around the world

Worldwide, renewable natural gas is dominated by biomethane, which can be generated from organic materials and residues from agriculture, food production and waste processing.

Multiple products of anaerobic digestion.
Modified from ADBA with permission

The top biomethane-producing countries include Germany, the UK, Sweden, France and the United States, and many others are planning to use renewable gas more widely.

A 2017 report suggests that renewable natural gas could meet 76% of Europe’s natural gas demand by 2050.

What is biomethane?

Biomethane is a clean form of biogas that is 98% methane. Also known as green gas, it can be used interchangeably with conventional fossil-fuel natural gas.

Biogas is a mixture of around 60% methane and 40% carbon dioxide, plus traces of other contaminants. Turning biogas into biomethane requires technology that scrubs out the carbon dioxide.

Biomethane’s benefits include:

  • Net zero emissions
  • Interchangeability with existing natural gas usage
  • Ability to capture methane emissions from other processes such as landfill and manure production
  • Potential economic opportunity for regional areas
  • Generation of skilled jobs in planning, engineering, operating and maintenance of biogas and biomethane plants.

Australia’s potential for biomethane

While Australia currently does not have any upgrading plants, the production of biomethane can provide a huge boost to Australia’s nascent biogas industry.

The main use for biogas in Australia is for electricity production, heat, and combined heat and power.

Australia’s biogas sector has more than 240 anaerobic digestion (AD) plants, most of which are associated with landfill gas power units and municipal wastewater treatment. They also include:

  • about 20 agricultural AD plants, which use waste manure from piggeries
  • about 18 industrial AD plants, which use wastewater from red meat processing and rendering as feedstock for biogas production;

There is also manure from around one million head of cattle in feedlots, which is currently not used to produce biogas, but is stockpiled for use as fertiliser on agricultural land.

Australian biogas facilities.

There are untapped opportunities to produce biomethane using municipal sewage sludge, red meat processing waste, residues from breweries and distilleries, food waste, and poultry and cattle manure.

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The Australian Renewable Energy Agency is currently supporting the Australian Biomass for Bioenergy (ABBA) project. The Australian Renewable Energy Mapping Infrastructure (AREMI) platform will map existing and projected biomass resource data from the ABBA project, alongside other parameters such as existing network and transport infrastructure, land-use capability, and demographic data.

This topic and many others related to biogas and bioenergy more widely will be discussed at this week’s Annual Bioenergy Australia conference.

Of course, biomethane is just one way in which Australia can make the transition to a low-emissions future. But as natural gas is already touted as a “transition fuel” to a low-carbon economy, these new technologies can help ensure that existing gas infrastructure can still be used in the future.The Conversation

Bernadette McCabe, Associate Professor and Principal Scientist, University of Southern Queensland

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

How catching malaria gave me a new perspective on saving gorillas

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Mountain and lowland gorillas are vulnerable to malaria.
Zoos Victoria

Marissa Parrott, University of Melbourne

Conservationists are in a desperate fight to save the last of the world’s gorillas. Numbers of some subspecies are so low that organisations are literally saving the species one gorilla at a time.

A perhaps unlikely foe in this battle is human-borne disease, including malaria, which has the potential for transmission from people to gorillas via bites from female Anopheles mosquitoes. Central Africa, the home of the gorillas, is highly susceptible to this disease, driving poverty and desperation amongst its communities.

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As human populations expand and deforestation increases, gorillas are brought into closer contact with people and the risk of disease transmission rises – with devastating effects.

Malaria infects people and our great ape cousins

A male mountain gorilla in Virunga National Park.
Marissa Parrott/Zoos Victoria, Author provided

In 2012 and 2017, I was lucky to see the magnificent, gentle and intelligent gorillas up close in both Bwindi Impenetrable Forest in Uganda, and Virunga National Park in the Democratic Republic of Congo.

I learned about the vital work of Zoos Victoria’s partner, Gorilla Doctors, in the protection and veterinary treatment of gorillas.

Malaria is the biggest disease killer of humans of all time, having claimed billions of human lives. Roughly half of the world’s population is at risk, and around half a million people die from the disease each year.

While the effects of malaria on human communities are horrifying, the effects of this and other human-borne diseases on gorillas, with so few remaining, pose the threat of extinction.

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At least 10 species of malaria can infect gorillas, with three being the same or highly similar to those found in humans. In one study, more than 30% of gorillas were infected with malaria parasites. However, difficulties in studying the often remote and critically endangered gorillas means potential transmission pathways remain unknown. More research is required to determine the effects of this disease and how to protect gorillas in the future.

My own battle against malaria

Despite never feeling or seeing a mosquito bite, I learned about these issues first-hand when I caught malaria myself.

During my PhD, I taught practical classes on malaria, and it was this knowledge that led me to believe I was in trouble in 2017.

The author wearing a face mask to protect gorillas in Virunga National Park.
Marissa Parrott/Zoos Victoria

Despite taking malaria-prevention medication, I had encountered one of the few diseases found in both humans and gorillas: Plasmodium ovale, a parasite that appears to be growing a resistance to some medications.

My local Australian doctors had never encountered this species, and despite blood tests showing massive liver damage, I was not diagnosed for weeks. I spent a week in hospital, hooked to intravenous fluids, and left in a wheelchair.

The effects of malaria are horrific. P. ovale has a 49-hour life cycle, bursting in their millions out of blood cells to infect and multiply. The first sign is nerve pain – every touch feels like sandpaper – followed by a loss of circulation to your arms and legs, then crippling fevers, sometimes over 41℃. You shake so violently and uncontrollably that you tear your muscles. In the aftermath, your blood pressure drops, in my case close to half of what it should have been.

Malaria is also called “Blackwater Disease”, because your urine turns the colour of Coca Cola while your body excretes all your destroyed blood cells. On one hand this was fascinating to see. On the other, it was terrifying. I really needed those blood cells.

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Twelve months on, I’ve been lucky with my recovery. We don’t know whether a gorilla infected with P. ovale would suffer the same symptoms, but I can’t fathom the fear a gorilla could feel with this crippling disease. Or the pain a mother could feel while watching her baby convulse with fevers. As with human children, malaria and other diseases are often most prevalent in younger gorillas.

To protect gorillas, you must protect people

Thankfully, there is hope. Gorilla Doctors monitor Eastern Lowland and Mountain Gorilla families deep in the jungles for signs of illness and injury. They deliver hands-on treatment for viral, parasitic and bacterial diseases, often via darts, or in severe cases under anaesthetic. They also support research, with PhD students studying a variety of diseases including malaria.

A young mountain gorilla in Virunga National Park.
ZoosVictoria/Marissa Parrott, Author provided

With such devastating diseases, the work of organisations to protect both local communities and gorillas is paramount. Ecotourism brings new people, and potentially new diseases in contact with gorillas. But it also brings crucial funding for the species and management of national parks. It is a delicate balancing act.

Studies suggest the greatest risk of disease transmission comes from local communities. Gorillas Doctors support One Health Initiatives for local communities and their domestic livestock. You cannot care for wildlife without caring for local communities and the health of staff who work in the national parks to protect the great apes.

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Visiting national parks and supporting well-run ecotourism brings much-needed income and attention to these areas, although you should see your doctor for appropriate malaria prophylaxis. Zoos Victoria also supports Gorilla Doctors’ work in the wild through their mobile-phone recycling program “They’re Calling on You”.

Support organisations to protect gorillas and the people who care for and live beside them.The Conversation

Marissa Parrott, Reproductive Biologist, Wildlife Conservation & Science, Zoos Victoria, and Honorary Research Associate, BioSciences, University of Melbourne

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