Just like other living organisms, trees can develop health problems. Health problems in trees are categorized as either biotic or abiotic disorders. Biotic disorders refer to health problems that develop when a tree adversely interacts with another organism. Abiotic disorders, on the other hand, refer to health problems when a tree adversely interacts with its inorganic surroundings.
In the case of biotic disorders, any time any other living organism attacks a tree it is considered a biotic disorder. For example, if a deer munches on your apple tree, this is a biotic disorder. Or, on the other hand, if gypsy moths devour the leaves on your tree, this is a biotic disorder. Simply put, treatment of the biotic disorder usually means getting the attacker to leave the tree alone but sometimes this is impractical, unwise or unnecessary. For example, it is impossible for you to eradicate the deer population from Lackawanna County. It would be unwise for you to destroy many benign insect populations just to stop the cyclical gypsy moths. It is unnecessary for a tree always to keep perfectly green leaves for the entire growing season.
In determining the treatment of biotic disorders, I recommend the following approach:
Step 1. Find out if the biotic disorder is killing the tree. Repeated removal of all the tree’s leaves will eventually kill the tree.
Step 2. Determine what is attacking the tree.
Step 3. Decide whether it is possible, practical or wise to eradicate the attacker.
Step 4. If the tree will not win the fight without lifelong extraordinary help from you, consider removing the tree and planting a species less vulnerable to attack. For example, as beautiful as ornamental flowering cherry trees are at this time of the year, I never recommend planting them because they are too susceptible to biotic disorders.
In the case of abiotic disorders, it is time to become Sherlock Holmes. Abiotic disorders can usually be traced to a “crime” against an otherwise healthy tree. Human beings, a living organism, are usually to blame for these crimes. If you find yourself asking, “Why did my tree, which was always so healthy, suddenly go into decline?” you need to look back in time, usually no more than five to ten years. “Do you mean that four years ago when we added that addition out back and the contractors were driving and parking all over the front lawn that might have damaged the tree? But the lawn is fine.” Did you replant the lawn? “Yes.” Well maybe now you will have to replant the trees.
The point is that with good questions, you can often trace the abiotic source of your tree problems. The good news is that you can avoid causing these problems. Treat your trees gently and they will most often adapt to their settings and thrive.
Joshua Arp is an ISA-certified Municipal Specialist, a Clarks Summit Tree Commissioner and an operator of a landscape maintenance business. He can be reached at firstname.lastname@example.org.