This story is based on the first tree-ring study of a wood sample collected in December 2000 from a fallen tree of Wollemi Pine. The study of tree rings is called dendrochronology.
“I am a Wollemi Pine. I was found in one of the sinuous canyons of the Wollemi National Park, about 200km from Sydney.
My life history has been imprinted in my tree-rings waiting to be read by those who understand trees. I was a tall, stately tree standing proud in this isolated grove with my identical siblings. But my living is now over and I lay decaying on the floor of the canyon with my nutrients being recycled. This canyon has been both my protector and my enemy. Let me explain.
The canyon where you found us in 1994 has afforded us protection from the great drying that progressively wiped out the extensive continent-wide rainforests that were once our home. In this canyon, our safe haven, we survived. However, we still have environmental enemies that periodically threaten us.
But let’s start at the beginning. I began my life some 300 years ago in a circle of siblings growing out from a common rootstock. Over past centuries this rootstock has produced many predecessors. As I grew, competing seedlings fell by the wayside as they couldn’t produce root systems fast enough to compete with my already existing system. I grew fast, adding as much as 1.0 m in height each year as I out-competed my identical siblings for the limited resources scavenged in this nutrient poor environment.
My antecedents had learnt long ago in the Cretaceous rainforests to wait patiently on the forest floor for a gap in the canopy to appear to provide the essential sunlight before they could race to push their leafy crowns out into the open space above; just as my relatives, the Hoop and Bunya-Bunya Pines, still do today. But the best example is the Klinkii Pine in New Guinea which reaches 70 m towering above the surrounding rainforest.
By around age 60 I had reached my maximum height of 40 m and began to add to my girth, but competition had now set in and it was a slow process. In some years I couldn’t add a complete tree-ring to the previous year’s growth. This growth in girth lasted for 100 years.
Towards the end of this time there was a rock fall from the cliff above, a large boulder hit my trunk high up in the crown gouging out the bark and exposing living tissue. Before I could seal it with my sticky milk-like sap, bacteria and fungi settled in and began to stain and rot my woody tissues.
A rare fire passed by but didn’t damage me as my thick basal bark protected me. It had started in the dry forest on the plateau above with pieces of burning debris falling into the canyon and igniting scattered dry fuels along the canyon. It soon extinguished itself.
After my 200th birthday I got a new lease of life when a violent windstorm accelerated up the canyon smashing into our grove. I was thrown about. My branches were torn from my crown and I was bent over so far that internal damage occurred when a shear-stress failure, or wind-shake, occurred. This persists today as a large semi-circular crack extending for meters along my trunk.
My older branches, as they died, remained attached to my trunk and as it expanded, little by little each year, they were enveloped and became part of the trunk. You can see them on the cross section as traces which have persisted for over 200 years.
But worse was to happen to my siblings. One or more of them, I can’t recall how many, were smashed thundering to the floor of the canyon. This was more than 80 years ago. They have long since decayed leaving no trace. I know this because soon afterwards I was able to grow rapidly again in response to the surge of nutrients and space that became available to me.
Some 20 years ago there was another of those terrible turbulent windstorms and without the mutual protection of my siblings, I was bent double and finally my base split asunder. I crashed to the ground and this is where you found me decaying amongst my offspring which have sprung from the rootstock to repeat another life cycle.”
With thanks to Associate Professor Cris Brack, one of the authors of this story, for permission to reproduce it here.