If you have ever enjoyed the quiet of a hike on the plateau above the Illawarra Escarpment, you will know how enchanting it is when the afternoon’s golden light twists through Eucalyptus trees, black cockatoos soaring overhead. Lorikeets pick at banksias, perched like sentries atop pastel-coloured branches. Vibrant yellow wattles burst through the understorey, while Gymea lilies and grass trees chatter in the breeze. Time does not exist here. Ancient species have remained rooted to this place through droughts and floods, with millions of years remembered in their genes.

You don’t have to go all the way up the Escarpment. The legacy of ancient forests is preserved in the trees scattered across our urban landscape on the coastal plain and escarpment foothills from Kiama to Coalcliff, and beyond.

“Just go for a drive!" says Leon Fuller, author of Wollongong’s Native Trees. "You’ll see the rainforests and the Eucalypts on the Escarpment, and when you go to Sydney, you’ll see the vegetation profile of the Hawkesbury sandstone at the top of the escarpment cliffs. Near the beaches, you see coastal species."

Leon is a retired horticulturist and self-proclaimed “plant nerd”. Since discovering his passion for plants in the 1970s, he has built a legacy integrating the Illawarra’s wild species into urban landscapes like the University of Wollongong. He has also shared his knowledge generously, guiding many people through gullies of the Escarpment, and recording every leaf shape, flower and fruit along the way. His first book, Wollongong’s Native Trees, was reprinted in 2021, and continues to be celebrated as one of the best regional tree ID and appreciation guides.

“I did all that because I saw all these amazing plants around the Illawarra," he says. 

"Truly, I really was in awe of them all. I could look at these rainforest trees and see all the beautiful details in the leaves and flowers and fruits, and I just wanted everyone else to see what I was seeing.”

There is a huge diversity of plants in the Illawarra. Our flora form distinct communities separated by environmental factors like soil and elevation. Plant communities have adaptations, each for surviving in a particular subset of environmental conditions. This is why the characteristics and traits of tree species found in the gullies and creek lines of the Illawarra are so different from those found on the dunes and ridgelines.

Leon explains how these adaptations came about: “The plants in Wollongong are mostly here because they arrived in Australia from the north or moved with Australia from Gondwanaland. They’ve evolved over 30 million years, so they’ve been through a fair few changes in the climate. That’s reflected in their morphology in the fact that they have small leaves, small fruits and small flowers. They fruit in the colder times of the year as to not lose too much water; so, they are pre-adapted for heat.

"Somewhere in their genes, they are probably adapted to all sorts of other conditions including some we can’t even imagine, because the species that are here now have survived all types of variations.”

If the native plants of the Illawarra are adapted to a specific set of environmental conditions, then climate change may shift their distribution, Leon points out.

“As the continent heats up, the high temperatures are going to move further south.”

Theoretically, this would restrict cold-adapted species to more southern latitudes, reducing the area of suitable habitat and threatening their survival. The more specialised a plant species is, the higher its risk of extinction. So, which of our local plants will be most vulnerable?

“The thing about climate change is, we don’t know what will happen, and some species will be affected, for sure," Leon says. "It’s the eucalypts that are more vulnerable than the rainforest plants for instance, because eucalypts are much more sensitive to things like temperature, altitude and water availability.”

Acknowledging the concerns of scientists and conservationists, Leon has come to appreciate the resilience of the Illawarra’s plant species, and believes they will persist with or without our help.

“I’m not worried about our local species. I have a great deal of faith in their adaptability. I’ve been watching these plants for nearly the last 80 years, and they’re really tough," he says.

"As an example, when I was in the Berkeley Hills in the middle of a drought, all these introduced species were dying. The lantana looked sick. The Cotoneaster looked really sick. All these weeds looked really sick, and in the middle of it there was this one local rainforest tree, Guioa, sticking out of the middle of it all looking very happy. That was very symbolic to me of the adaptability of our local species.

“The natural east coast distribution of many (74%) of the Illawarra rainforest species extend into Queensland, with many being found right up into North Queensland and some beyond. Some “dry rainforest” species grow well up to 200km from the coast in Queensland. These occurrences are a tribute to their tolerance of a great range of climatic conditions, including hot, dry conditions.”

Leon has demonstrated that the trees have much wisdom to offer us, if we are willing to listen. They have survived mass extinctions and natural disasters, and they have survived us. If we can learn to change with our environment, finding our place in nature’s story; then we can be less afraid and better equipped to face the perils of climate change.

This is a story of awe and respect for the resilience of the amazing natural world around us.

If you want to learn more about our native species, including how to bring them into your homes and communities, go to the Growing Illawarra Natives webpage.

Love local flora?

There are three treats on this weekend:

• Spring Open Days at Illawarra Grevillea Park Botanic Gardens with expansive native display gardens; a rainforest walk; picnic areas; a sensory trail and extensive range of plants for sale, including hard to find grafted grevilleas. From 10am-4pm on the first two weekends of September.
• Terra Motion, an exhibition by Ash Frost and Hal Pratt, will be at Clifton School of Arts until September 7, enquiries to 0410 888 964. Works celebrating the Wodi Wodi Track: 200 million years of landscape, wildlife, and enduring natural wonder. Art in motion, shaped by the escarpment’s timeless geology and living rainforest.
• Volunteers at The Illawarra Rhododendron and Rainforest Gardens will offer free guided rainforest walks to visitors every Saturday and Sunday in September. Read more here