Random observation during a forest walk allowed scientists to prove that trees can keep each other alive by sharing water and other resources – a kind of "superorganism" that works together to keep humans alive.
In this way, a tree stump could survive even without its own leaves and circulate water.
Ecologists Sebastian Leuzinger and Martin Bader discovered the seemingly dead Kauri Pine Stump ( Agathis australis ) in one of the forests of New Zealand's North Island, but it did show something dead trees do not have: sap flowing through them ,
By measuring the flow of water in the tree stump and in the surrounding trees, the researchers found that they fit together closely, suggesting that the closest neighbors of the kauri pine tree are living them. That raises another question ̵
"For the stump, the advantages are obvious – he would be dead without the transplants because he does not have his own green tissue," says Leuzinger.
But why should the green trees keep their grandpa alive on the forest floor while he seems to offer nothing for his host trees?
Leuzinger and his colleagues believe that the roots of the tree stump have been grafted with the roots of other trees, something that is known to happen when trees feel they can share resources with the trees around them In these grafts, trees can form a kind of "superorganism" in a forest and help clumps of trees to improve their collective stability.
But it rarely happens in dying, living stumps – scientists have guessed that it continues to do so, but earlier research is decades old and inconclusive in terms of underlying mechanisms: it has never been seen in kauri trees.
Water is normally pulled through trees because it evaporates from the leaves and This can not happen in the tree stump, but the water continues to flow – albeit at a slower rate than the surrounding ones Trees.
"This differs from the functioning of normal trees, where the water flow is driven by the water potential of the atmosphere," says Leuzinger.
"In this case, the stump must follow what the rest of the trees do, or it must use osmotic pressure to propel the water flow as it lacks transpiring leaves, and it escapes the atmospheric draft."
Es It's still not clear what the surrounding trees will do to a shop like this. It is possible, according to the researchers, that the connections were made when the tree stump was still a healthy tree, and that you simply can not let go.
Perhaps the surrounding trees can expand their own root networks and collect more water and nutrients by maintaining contact with the stump.
More research is needed to be sure. In the meantime, the study proves that trees are more interconnected than we might have thought – and that they also look after the retirees of the tree community.
In times of rapidly changing climate, such research could be crucial in finding out how forests and forests will adapt over the coming years.
"This has far-reaching consequences for our perception of trees – we may not really be dealing with trees as individuals, but with the forest as a super-organism," says Leuzinger.
The study was published in iScience .