New Zealand is home to the world's third largest species of tree. The kauri, or agathis australis, can grow to heights of up to 50 meters and have a width of more than 15 meters. But the monumental size of these trees isn't what has scientists excited. Instead, it's the amazing discovery of a living kauri stump that is challenging common knowledge of how trees and forests interact.
It has always been believed that stumps are just the grim remains of a deceased tree, but with the discovery of the living kauri pine stump, scientists are now questioning everything they know about the interworking of the forest system.
While using a popular walking trail, Sebastian Leuzinger and his colleague Martin Bader came across the stump. "Ninety-nine percent of the population would probably walk past it and think it's a dead tree," Dr. Leuzinger told ABC in an interview. But the scientists from Auckland University of Technology noticed colors on the stump that implied it was still living.
Their study was recently featured in the journal iScience. This type of life support system has never been recorded in any species of tree, and if confirmed, could essentially rewrite just how forests are understood to work.
The ideology that a forest may in fact be a superorganism is at the forefront as one of the possible explanations for the living stump. As a superorganism the forest would act as one living system connected through roots and sustaining tree life, rather than individual trees solely living on their own.
If this is the case, and the other, healthier trees are some how keeping the stump alive, what is the purpose? This is the question that has scientists "stumped". Scientists believe that the stump was originally connected to the root lifeline when it was still bearing leaves and that it may actually assist in the water and nutrient collection for the other, still growing, trees nearby.
Plant physiologist Brendan Choat, from Western Sydney University, had this to say regarding the research of which he was not a part of, "This is certainly the first time I'm aware of a [study] showing really concrete hydraulic connections between a stump and a surrounding tree."
But this isn't necessarily good news for kauri pines. If the kauri pines are in fact using their roots to share water, that would imply that there's a risk of also sharing disease throughout the forest. The kauri are currently threatened by a pathogen known as Phytophthora agathidicida, which has caused diebacks.
It has long been believed that the disease was spread from tree to tree on the shoes of loggers and other visitors to the forest, but with this new discovery, that may not be the case.