#cook pine

THE CURIOUS CASE OF THE LEANING COOK PINE

When I was much younger, I remember there being a pine tree in our front yard and we would play for hours in its shade. It was known as the Christmas tree because it resembled one so closely. Unfortunately, my father had to cut it down because it was very tall and leaned toward our house, threatening to demolish it. It turns out what might have been growing in my front yard was a Cook Pine (Auricaria columnaris).

The Cook Pine was first described from specimens collected on Captain Cooks 2nd circumnavigation voyage. They originate in New Caledonia, a group of archipelagos in the Pacific, east of Australia. They are, however, planted in many public areas around the world including Australia, New Zealand, California, Mexico and Hawaii. If you’ve ever seen one of them, you would’ve noticed that it has a very interesting quirk. Cook pines lean to one side, in a very Tower of Pisa fashion. Scientists have discovered that that this behaviour is non-random and after sampling 256 trees across the globe, each located more than 500 km away from the other, they found that 91 % demonstrated leaning towards the equator. This means that Cook Pines in the north lean southwards whereas those in the south lean northward. This effect was also found to be more pronounced at higher latitudes, with trees appearing more slanted. The leaning characteristic among Cook Pines is so ubiquitous that it was used to distinguish the species from related members of its family.

Why does the Cook Pine grow in this manner? Researchers are still trying to figure this out. The factors governing the vertical form of a tree is well studied and has been shown to have genetic and environmental controls. Vertical shoot growth is also influenced negatively by gravity (gravitropism) and positively by light (phototropism). This is basically how shoots grow upward, and roots into the soil. Many molecular processes govern the orientation of a plant and the genes for some of these have been identified. However, it is still uncertain how these processes work or what exactly controls them. Non-vertical growth does occur in some plants that are exposed to extreme environmental conditions. An example of this are the the crooked appearance of trees at Slope Point in New Zealand caused by extreme windy conditions. Changes in the direction of solar illumination may also influence the vertical orientation of shoot growth. Another anomaly among pine trees are those of the Crooked Forest in Poland which consists of trees whose trunks are all bent at 90 degrees. This however, is thought to be the work of human interference, although the reason is unknown. What’s interesting about the trees in Poland is that although the base of the trunk is bent, the tree form is still vertical, perhaps indicating the strong influence of phototropism. The authors believe that the characteristic leaning of Cook Pines may have occurred due to the adaptation of the plant to different incident angles of sunlight in the topics or earth’s magnetism, or the interaction of both these factors. These findings have led to further enquiry about the underlying mechanisms of the leaning characteristic and have given us much more to consider in determining the effects of the environment on plant physiology.

KR.

References and Further Reading: http://onlinelibrary.wiley.com/doi/10.1002/ecy.1850/full http://bit.ly/2s4gXAe http://www.thisiscolossal.com/2015/11/crooked-forest-poland/ http://www.sciencealert.com/welcome-to-slope-point-where-the-winds-are-so-fierce-the-trees-are-blown-back

Coral Reef Araucaria/Cook Araucaria. This one is in located in the pacific section of the gondwana arboretum, Auckland, New Zealand. its in a bit of an odd spot but I expect predates other plantings. Lovely tree with cones at the top you can see what is left of last seasons cone with the cone spikes, they are a lot bigger and the new cones growing in currently. The trunk curve is pointing pretty much north as they tend to do. cool tree!

Coral reef Araucaria by the old radio tower/booster “the drum tower” on the edge of Long Bay and Northcross, Auckland, New Zealand. Really cool with the classic lean, almost angled north! Super cool tree.