CODIT or Compartmentalization of Decay in Trees What is CODIT and why do you care? CODIT is a term first defined by Dr Alex Shigo. We had the privilege of meeting Alex in person, however much has been learned and built upon his original theories. Ensuring optimal care of trees is why it is mandatory that you only consider an ISA Certified Arborist (or higher credentials) for your tree(s). See our article on what is an arborist. Trees have the miraculous ability to protect themselves from injury or wounds, and are able to do it with varying degrees. Some items which impact how well they are able to protect themselves depends upon the time of year or season, the species of tree and the location and extent of wound or injury. In the later 19th century we had theories on tree decay, which were modified in the first half of the 20th century and have been recently modified again due to recent science and learning. We now know that when trees are wounded, many organisms infect the tree at different times and in different ways. Trees respond to these infections with both chemical and physical changes, discoloured and decayed wood is often the result. The impact of this discolouration and decay is limited due to compartmentalization. In the CODIT theory, there are four protection walls and two zones. The first three walls are in the first zone and the last wall is the second zone. Wall One: the first wall is formed by filling the normally porous vascular tissue above and below the injury, preventing vertical expansion of the injured area. This is the weakest of the 4 walls. Wall Two: the second wall is formed by forming a barrier on the inner growth ring, interior to the wound or injury, and preventing inner spread of the injury. This is the second weakest wall. Wall Three: the third wall is formed by the ray cells; these form a maze like barrier preventing lateral spread of the wound or injury. This is the strongest wall at the time of wounding and the strongest wall in the first zone. Wall Four: is created by new growth over the exterior of the tree. This isolates the tissue at time of infection, blocking oxygen and moisture entry into the area. This is the strongest of the walls and is the Barrier Zone, often preventing or halting the spread of infection. When this is the only wall that remains intact, you end up with a tree that appears solid but is completely rotted on the interior. It is important to understand CODIT, how a tree responds and why. How to properly cut a tree in a way that best ensures its ability to heal successfully. This is a case of where lowest cost is not best value, almost always! You see the long term health of your tree is at stake. Would you hire the lowest cost doctor to operate on your own leg? Why would you do the same for your tree? Simcoe Muskoka Tree Services Inc.
www.simcoemuskokatreeservices.ca