Magic dirt: bringing biodiversity back

Sustainable City At Work

A failure to mow the lawn usually doesn’t deliver anything good except when you discover a rare native Australian grass that’s been hiding in plain sight.

This is one of the terrific tales of biodiversity in the Adelaide Park Lands shared by Gemma Bataille, Leading Hand of the City of Adelaide’s Biodiversity Team. She’s imparting her horticulture wisdom to a group of people who have come for a guided tour of a corner of the Park Lands. It’s a rainy morning but that hasn’t dampened our spirits or the evident passion she has for her work.

“We are so lucky to have Park Lands in Adelaide. To be a capital city surrounded by park is really important and the only reason the remnant vegetation we have has been protected is because of people’s investment.”

- Gemma Bataille, Leading Hand, Biodiversity Team

Gemma horticulture

GEMMA BATAILLE SHARING THE LATIN NAMES OF ALL THE NATIVE SPECIES

Park tour group

THE WEATHER RESILIENT TOUR GROUP

Gemma and her small team have the lofty task of looking after and advancing the areas of native landscape in the park lands. The importance of the work of her team cannot be overstated. They have revegetated, revived and preserved sites that pre-date European colonisation (remnant sites).

One of the Park Lands most prominent remnant sites is the grassland in Victoria Park / Pakapakanthi. Post-European colonisation, it had many land uses including a football oval and grazing land. By luck, during a lengthy period when the mowing team weren’t able to access the area, the grass had an opportunity to grow long enough to be identified as native species.

“It’s a testament to the resilience of native species—they can be mowed every six weeks for 50 years, they can be grazed, they can have all kinds of land uses on top of them and they still come back with the right land management techniques.”

- Gemma Bataille, Leading Hand, Biodiversity Team

This grassland is not the only surprise that the Biodiversity Team has managed to unearth. “Once you start revegetation, native species start to pop back up. We have a series of wetlands in GS Kingston Park / Wirrarninthi that were constructed as flood mitigation. The re-entry of water and a little bit of revegetation created the opportunity to remnant reed species to come back."

"We have an endangered species that has just come back because we created the right environment for it. It’s incredible what the dirt can hold.”

- Gemma Bataille, Leading Hand, Biodiversity Team

So why is this biodiversity so important? Gemma delved into that question by touring the group along the Bunyip Trail in Bonython Park / Tulya Wodli. While not a remnant site, the trail showcases some of the Park Lands’ native species (as well as a very sweet children’s story trail).

This site underwent revegetation in 2005 as part of the Million Trees Project in partnership with the State Government. This revegetation transformed this site into one that is closer to what existed before European colonisation, when the Kaurna People of the Adelaide Plains lived in harmony with the land. 

THE TORRENS RIVER / KARRAWIRRA PARI IN 2003 and 2005 BEFORE and after REVEGETATION 

In 2016 there was a flood event that severely damaged this particular site and resulted in the loss of the small and medium sized trees (the bottom and mid-story canopy) and resulted in the revegetation needing to be completely redone. The loss of the mid-story means there is no longer a protective habitat for small birds, which are crucial to maintaining tree health. 

Bonython river flood

THE TORRENS RIVER / KARRAWIRRA PARI DURING THE 2016 FLOOD

Gemma shows us a gum tree with leaves covered in sugar lerps, left by insects leaching fluid from the tree, and black marks that indicate disease. If there were small birds in this area, they would eat those insects and this tree would be healthier.

So how do we attract more small birds? It comes down to habitat—grow it and they will come. Many of the small birds that these trees need only have a short home range, meaning they can only travel short distances from their nesting tree for food. So when there is once again a mid-story canopy for the birds to call home, they can return and save the trees. 

“Creating a habitat for certain species is really important to maintaining the loop of an ecosystem.”

- Gemma Bataille, Leading Hand, Biodiversity Team

THE TORRENS RIVER / KARRAWIRRA PARI 2003 and 2020 BEFORE AND AFTER TWO ROUNDS OF REVEGETATION AND YEARS OF RECOVERY

This is why the work of Gemma and her team is so important, some of the environmental damage of European colonisation needs to be repaired to faciliate that loop. While the trees are slowly regrowing, the team work to revegetate the surrounding area with a diverse range of shrubs and ground covers. The aim is to replicate what is found in natural woodland and forest habitats and to provide a range of food sources, primarily nectar and insects, that can be used by birds.

This is slow growing but crucial work. It's not just this one site that is getting this treatment either, the team are doing this across the entire Adelaide Park Lands. They’re removing weeds by hand to give native species room to grow, they’re revegetating creek beds, they’re planting food for the native bees… it goes on.

A selection of the native flowers you can find along the Bunyip Trail.

But it’s all for a good cause, and not just for the animals says Gemma.

“The Park Lands are a really nice place to bring kids to play... I really love to see families bringing a picnic down here, kids on their bikes and running through the bush and throwing sticks in the river and having a childhood that is more familiar to me as someone from the country. I really value seeing kids getting that experience.”


Learn more about biodiversity projects in the city of Adelaide.

Find out more about getting involved in biodiversity and the grasslands in Victoria Park / Pakapakanthi.

This tour was part of a free series offered by the horticulture team, if you would like to stay up to date with upcoming events in the city sign up to the City of Adelaide What's On Newsletter or visit the webpage.

CITY OF ADELAIDE STRATEGIC PLAN CONTEXT

Outcome 3: Dynamic City Culture -Council will continue to create a beautiful, diverse city that celebrates its natural, cultural and built heritage.

Article by

Georgie Smith

Georgie Smith

Maker and curator of things

Georgie has been BFFs with Adelaide her whole life. They’ve shared many special moments: over cheese platters at art exhibitions, cycling through the park lands and immersed in sequin-clad theatre shows.