Ants and their plants
A childhood spent playing in the wild and conducting experiments at home set the foundation for Melinda Greenfield’s love of science. However, rather than following the common route to becoming a scientist, her wanderlust inspired her to travel the world. Melinda explains how volunteering led to her becoming a scientist and why it’s never too late to follow your passion.
“The one thing all ant-plants have in common is that they are plants that provide a nesting place in which ants can live,” she says. “In ant-plants from other parts of the world, the nest is provided in their leaves or their stems. With our Australian ant-plants, the nest is provided within this spiky structure, called the domatia.”
Melinda explores the hidden chambers of the domatia of the ant-plant Myrmecodia beccarii. Some of the tunnels and chambers of this ant-plant are dark black because the Golden Ants use these areas as toilets and waste chambers. Other chambers are yellow and this is where the ant colony keeps their brood (eggs, larvae and pupae).
“About 40 years ago, some fungi were found in the chambers but nobody has looked at what those fungi are, how it gets there, what the ants are doing with it and whether the fungi have a role to play in this ant-plant mutualism,” Melinda says. “This is a mutualism — the plant provides the ants with somewhere to live and the ants deposit their waste in the plant, effectively fertilising the plant. What we don’t know is whether or not the fungi are important in the transfer of the nutrients to the plant or if the ants are farming fungi.”
More than just ants and plants
Melinda has travelled to Cardwell, Cowley Beach, Port Douglas, Annan River and Kutini-Payamu (Iron Range) National Park to collect ant-plants for her research. Her work involves cutting open the spiky plants, collecting the fungi and ants out of them and then extracting DNA from the fungal samples.
“In nature, fungi are often involved in nutrient transfer so I think the fungi are going to have something to do with nutrient transfer in this ant-plant and that is really cool,” she says. “Fungi have been ignored for a long time and discovering their role in this ant-plant could change the way we view these mutualisms, which is a big deal. There’s so much more to it than just ants and plants.”
That something more includes the possibility of discovering species of fungi that have not yet been described. Making that discovery will help to inform the management of the ant-plant, which is listed as vulnerable.
“The main threats are habitat loss,” she says. “Finding out if fungi are important will help in future revegetation projects, where it could be vital to ensure the fungi are present.”
Scenic route to research
Despite having developed a love of science and exploration as a child, Melinda did not immediately follow the traditional path to becoming a scientist.
She grew up on a semi-rural five acre property in western Sydney and loved being out in the natural world. She remembers watching The Curiosity Show and following their instructions to conduct mini-experiments at home. However, a passion for travel took precedence over science during her teenage years.
“I got distracted by wanting to travel and ended up leaving school after Year 10,” she says. “I went to secretarial college to learn administrative skills and began working as a legal secretary, but I never felt like I belonged. I was not ‘corporate law firm’ material and I never really liked it, at all, but it was good money and allowed me to travel around the world. It got me doing what I really wanted to do at that time.”
In her late 20s, Melinda started thinking about what she wanted to do in life. This prompted her to join WWF and the Australian Conservation Foundation. She took part in volunteering projects, including weeding in national parks.
“Then I joined Earth Watch and spent a weekend catching frogs in the Watagan Mountains, near Newcastle, north of Sydney,” she says. “So off I go with this group of volunteers, a professor and his PhD students, and we ran around the forest at night catching frogs, measuring them, weighing them, microchipping them — I had a ball. I loved it and had so much fun.”
That night, Melinda talked to a PhD student about the future and what she really wanted to do. The conversation sparked a thought process that ended with Melinda enrolling in TAFE six months later. She then completed a Bachelor of Science at JCU, which led to completing honours and being approached to do a PhD.
“I never thought I’d get this far,” she says. “I grew up in an area where very few kids went to university, only one friend went. It wasn’t really part of the conversation.”
Not only did Melinda go to university, but she continues to excel at JCU. The chance to explore microcosms and the variety of her work drives Melinda in her research. While it took her a while to figure out what she wanted to do with life, she feels grateful to have the chance to delve into the little-known world of fungi.
“A lot of people think, ‘oh fungi, it’s something that grows in the compost or between the toes’, but there is so much more to fungi than people realise. It often interacts with other species in many different ways, both positive and negative,” she says. “I think it’s a real privilege to do a PhD. I get to study this system that we don’t understand, it’s been ignored for so long, and I get to investigate it. I feel very fortunate that I get to do that and that I have support to do that.”
Melinda’s advice for people is to have a go at whatever they find fascinating, whether that’s working in nature, in a lab, in a creative studio or something else.
“Go out in the field and you’ll soon find out whether or not it’s for you,” she says. “That’s why volunteering and talking to an advisor helps. If you think you might like doing something, try to volunteer. You don’t know until you try.”