Cool facts on kauri from Bruce Burns and Sarah Wyse on day 2, accompanied by Harry Twyford and Simon Randall. Photo by Mels Barton
1. All plants need nitrogen but kauri can thrive on less than almost any other. They have an amazing ability to do well in poor soil. That is not to say they like infertile soil. In fact there is a myth that kauri are slow growers. Planted in rich soil in good conditions kauri can grow very fast.
2. Kauri forest accumulates biomass faster than most forests anywhere in the world. It grows more wood – bigger trees and more of them.
3. The kauri ecosystem is the most diverse forest type in New Zealand. Kauri forest includes around 70 plant species in a 400 sq m plot. Compare that with South Island mountain beech which has only 2-3 species. This has implications for kauri dieback because if we lose the kauri then the bush will become a lot more homogenous and less interesting.
4. The kauri has powerful anti-competitive strategies that allow it to dominate other species. Kauri leaves and bark fall to the ground producing a litter that is acidic, slow to break down, and low in nutrients, making it hard for other species to compete in the same space.
5. The kauri has evolved a continuous self-pruning mechanism. The lower branches continually drop off leaving the tree with a smooth trunk and timber without knots. This is what made kauri so prized by the British navy for masts in the early 1800s. Missionary Samuel Marsden organised for ships that had transported convicts to Australia to call by New Zealand to pick up masts to take back to Britain.
6. Northern Maori used to chew kauri gum as an aphrodisiac, a natural Kiwi viagra. (I got this from a good source; unverified but in my view worth including).
Day 2 on the trail – Several hours walking from Huia to Mt Donald McLean with Bruce Burns who is senior lecturer in plant ecology at Auckland University, and PhD candidate Sarah Wyse who is doing her thesis on kauri ecosystems. It was a rare privilege to walk in the bush with people who know so much about it. Then we walked the Omanawanui Trail down to Whatipu – a three hour gutbuster with stunning views across the Manukau heads and out to the bar. Tomorrow we walk from Whatipu to Karekare.
Still a way to go to Whatipu from the Puriri Ridge Track. Photo: Mels Barton
Manukau Heads from the Omanawanui Track. Photo: Mels Barton