It was one of those surprise phone calls.
Hi! I’m calling from Margaret River in Western Australia. I’ve got a blackwood plantation.
Now I’ve been to WA a few times and through Margaret River (MR) a few times. I thought I knew the country pretty well and I never dreamed of blackwood growing there. Other parts of the South West perhaps but not around MR. It’s mostly dry scrubby Jarrah/Marri country with a bit of taller Karri scattered about.
But as the phone conversation developed it became clear that something unique was happening. I certainly couldn’t believe what I was hearing.
Can you send me some photos? I asked.
A few days later the photos arrived in the email.
Blackwood (Acacia melanoxylon) is not native to Western Australia.
Here is a 0.7 ha blackwood plantation containing 900 trees, unthinned and pruned to just 1.8 metres. But the great form and the growth rate of these blackwoods shows there is potential for growing commercial blackwood at MR. The plantation is about 20 years old. The largest tree is 60cm diameter with 26% of the trees greater than 30 cm. The arithmetic mean diameter is 25.6, whilst the quadratic mean diameter is 26.6cm.
What’s more, the current basal area is 45 square metres (67 square metres per ha equivalent)!! This is a very productive site for blackwood.
If this plantation had been thinned and pruned on time it would now contain 140 trees well on the way to commercial maturity. That’s equates to about 210 cubic metres of premium blackwood sawlog at harvest.
So what can be done with this plantation in its current state?
I don’t regard this plantation as a failure. Quite the opposite. This is a brilliant first step on the way to success.
Having clearly demonstrated the potential of the site for growing commercial blackwood, a way needs to be found to salvage what value we can from the current crop of trees and gradually convert the plantation into a well managed profitable commercial blackwood plantation. There is even the opportunity for expansion.
Those dead branches in the photo potentially represent compromised wood quality. Some of these trees will need to be cut open so we can see what’s inside.
Luckily MR has a thriving wood craft industry so some of this wood will hopefully make its way to the craft market. MR also has a healthy firewood market so the thinnings from the plantation can be readily sold.
Stay tuned as we follow the progress of this extraordinary blackwood plantation in Western Australia.
For a 20 year-old unmanaged blackwood plantation that is an amazing sight!
PS. I need to emphasize that the extraordinary form of these blackwoods is not due to the close spacing of the trees in this plantation. That is a common belief that is not supported by science. Whatever the cause of this example of consistent good form (genetics, environment or GxE) it is very unusual. The usual recommendation to achieve good form in commercial blackwood is i) good site selection, and ii) pruning!! Tree spacing has only a small impact on blackwood stem form.