Many beautiful beasties live in wet sclerophyll forest, including those that dwell or nest in the hollows of venerable old trees. Gliding possums that eat leaves, blossoms or trees sap; owls, tree-creepers and parrots; bats, snakes and antechinuses¹. As I started drawing my next forest portrait, the shape of the tree branches reminded me of these hollows, and the beasts that might be dozing within. I had decided to draw another ‘flavour’ of wet sclerophyll forest: one dominated by the blackbutt, Eucalyptus pilularis. Blackbutts, like many other eucalypts, develop ‘bayonet’ and ‘elbow’ -type branches, which often produce hollows as they age.
It’s hard to find large old trees in our forests, since so many places have either been logged over or burnt in the last 100 years or so. (And these blackbutts only start forming hollows well after their 100th birthday. A remarkable study by Mackowski² estimates that hollow formation only really gets going when these trees are 144 to 194 years old.) Often the only large, old trees that remain are those that were too gnarled and crooked to be useful for timber. Here’s one that the lovely Ray and I found when we went looking for big blackbutt trees in Bellthorpe State Forest. Can you spot the bayonet and elbow branches?
This forest portrait would be different from the first in a number of ways. Most obviously, it would feature blackbutts instead of flooded gums, but I also wanted to capture the misty atmosphere of a drizzly winter day – just like it was out in the forest when I was doing my preliminary sketches. It would also have a grassy understorey, which I find intriguing – since I’m more familiar with the dark, dense, shrubby understory of wet sclerophyll forests in Victoria. The wet sclerophyll forests here in south east Queensland can have either a grassy or a rainforesty/shrubby understorey. Both understorey types, and the ecotones they create, provide important habitat for threatened species such as the eastern bristlebird and Hastings River mouse.
As always, it was important to include people in the picture to provide scale. I was first introduced to these grassy-understoreyed forests by the Queensland Herbarium botanists – so who better to include in the picture? Here’s a couple of them hard at work:
So once again, I took all my sketches, photos and mental images back home and started drawing. After many days, this is what emerged:
What do you think of this next forest portrait? The intense green of the grass is the actual colour we get up here, in subtropical Queensland – even (or maybe especially) on a cloudy day. The rainforest plants – including two different types of palm – are hanging in there, on the left-hand-side of the picture. These fire-sensitive plants will spread out to colonise the grassy area if there are no fires for a while. You can see evidence of a fairly recent fire in the black charcoal marks at the bases of the trees on the right. And there are a probably a number of hollows in these old, bumpy trees, including in their elbow branches. Who knows what creatures might be snug and fast asleep, high above those busy botanists way below?
1. Small marsupials that look somewhat like rodents, but are fearsome predators.
2. Mackowski,C.M. (1984) The ontogeny of hollows in blackbutt (Eucalyptus pilularis) and its relevance to the management of forests for possums, gliders and timber. pp. 553-67 in A.P. Smith and I.D. Hume Possums and gliders, Australian Mammal Society, Sydney.