In the truest sense of the word, trees don’t “heal.” they are doing not repair and regenerate tissue as animals do; rather they compartmentalize damaged tissue with specialized cells, and grow new healthy wood around the damage. The damage itself isn’t repaired; it’s simply separated by a physical barrier of cells to stay any infection from spreading to the remainder of the tree. These barrier cells are called woundwood or callus tissue. Example of Compartmentalization of Decay
The Branch Defense Zone
The term for this process is “CODIT,” or Compartmentalization Of Decay In Trees, coined by renowned arboricultural scientist Dr. Alex Shigo in 1986. While trees can create woundwood anywhere the damage occurs, the method is fast and effective when it’s triggered within the collar (the swollen ring where the branch meets another branch or the trunk). The collar contains specialized cells called the branch defense zone, which activate the expansion of woundwood. When making pruning cuts, it’s essential that the collar never is damaged within the process. If the branch defense zone is broken, it’ll prevent the right growth of woundwood round the cut. this will cause improper compartmentalization, decay and even death of the tree. Branch collar. The branch defense zone is that the tree’s natural emergency decides to save the remainder of its “body” if a limb is severely damaged: it’ll seal off that limb from the remainder of the tree by creating a layer of barrier cells at the limb’s junction. Once sealed, the remainder of the limb won’t receive any longer nutrient flow and can eventually die. Should woodpeckers, insects, fungus, or other creatures create further damage during this deadwood, it’ll not affect the remainder of the tree, and maybe pruned off or will eventually fall off and be recycled as an organic matter within the soil.
Sapwood versus Heartwood
However, not all branch damage leads to the compartmentalization and decay of entire limbs. this is often partially thanks to the differences within the wood composition. Sapwood, the outer region through which nutrients and water flow, is very immune to decay and is thus less likely to be compartmentalized than heartwood, which has no resistance to decay. Branches that are but 2 inches in diameter are typically composed entirely of sapwood. At around 4 inches, the high percentage of heartwood within the branch makes it highly vulnerable to decay. pruning a little branch. This science is often applied when making decisions on where to form a pruning cut. Since small branches heal easiest, and with the smallest amount risk of infection and decay, it’s best whenever possible to form pruning cuts that are but 2 inches diameter. you ought to train your young tree to its final shape within the first few years of its life, while the branches are still small. If you are doing got to make a bigger pruning cut, you’ll help your tree to heal as absolute best by fertilizing properly, providing adequate water, aerating the soil if it’s compacted, and treating any diseases and pests as required. By keeping your tree in good overall health and reducing stress, it’ll have a far better chance of surviving a potentially dangerous large cut.