The graft point of the ‘Franklin Tree’ in 2008 prior to the suspected lighting strike, showing a healthy crown of Rusty Gum merging with the Pink Bloodwood branch. Photo by Trevor Franklin.
While recently visiting a Land for Wildlife property, I was shown a tree that had grafted to another. This natural phenomenon, although not so rare, can be hard to notice. The landholder, Trevor Franklin, led me to what looked like a Rusty Gum (Angophora leiocarpa) that changed to a Pink Bloodwood (Corymbia intermedia) halfway up. I stood astounded, looking at a free-standing tree with a trunk of one species and a crown of another. In fact, not just another species, but another genus, and it had all happened naturally.
Likely about 50 years ago, this Rusty Gum grew beside a smaller Pink Bloodwood. Possibly due to strong storm winds, the bloodwood fell eastward, onto the Rusty Gum. They then would have rubbed against each other’s trunks for some time, eventually wearing away their bark to uncover the cambium layer beneath. Somehow, they held still in this position long enough for a graft to form. This is like what is called an ‘approach graft’ in horticulture, albeit on a much larger scale and without the help of grafting knives and tape.
The Pink Bloodwood’s trunk then died, but the graft enabled the crown of the bloodwood to survive. The old leaning trunk had lost all sapwood through natural attrition, probably helped by termites, borers, and fungus. A thin heartwood core is all that remains of the bloodwood trunk, pointing to where it once stood upright decades before.
As for the Rusty Gum, a once healthy wide-spreading crown, as seen in a photo taken in 2008, is now completely dead above the graft union approximately five metres from the ground. A massive scar extends down the length of the merged tree, which appears to have been caused by a lightning strike. The graft union was amazingly spared, while the Rusty Gum’s top was so severely damaged that the Pink Bloodwood’s crown completely replaced it.
Just ponder what this tree has been through in its life. It was probably a handsome, perfectly formed, upstanding tree before any of this drama started to play out. Although it would not win any beauty contest now, like many of us, the good form of its youth has been more than surpassed by its interesting presence.
Many would not notice this venerable tree, but its existence is truly significant. I call it the ‘Franklin Tree’, after Trevor, who has owned this bush block for over 20 years. In the past he ran a native tree nursery in the corner of his block, near the ‘Franklin Tree’. He is a Land for Wildlife member, managing this 16-hectare block as wallum woodland, conserving this ecology in an area of rapid population growth and social change.
Jim Johnston
Land for Wildlife Officer
Fraser Coast Regional Council