It’s relatively easy to see the limb that needs to be pruned, the leaf that is yellowing, or the borer hole in the bark. However, it isn’t exactly easy to get a glimpse at the issues that lie beneath the soil: roots girdling your tree’s trunk, being attacked by root rot and decay fungi, or suffocating under compacted soils. Fortunately, arborists can see beneath the soil — thanks to a process called air excavation.
It is no surprise that the root system plays a vital role to the health of your tree. We all learned in grade school that a tree’s roots absorb water and nutrients from the soil. But they do more: a root system stores the tree’s energy reserves, offers structural support, and allows for the exchange of gasses.
What many do not realize is that 80% of a tree’s roots are located within 2-3 feet of the soil surface and spread as much as 2 to 3 times the height of the tree. A tree’s root system is massive, but it is also delicate. Because of its size and placement, a tree’s root system is quite susceptible to stresses induced by compacted soils, poor planting conditions, or construction work.
Until recently, the only way to inspect a tree’s roots was to conduct a sort of archeological dig. The process was time consuming and had the potential of doing more harm than good. However, through the use of compressed air and the process of air excavation, a tree’s roots can be exposed with minimal damage to the root structure.
It seems odd. You would think that highly pressurized air shot at a tree’s roots would cause some sort of damage. However, because tree roots are not porous, they are not disturbed by air excavation. The procedure has proven to be invaluable in performing a number of diagnostic evaluations. Air excavation can be used to inspect root collars, prevent and mitigate construction damage, perform soil replacement therapy, transplant trees, conduct arboricultural research, or even deter the spread of diseases like Dutch elm disease and oak wilt by uncovering root grafts.
The information learned from actually looking at the roots can help arborists take the steps necessary to safeguard your tree’s health and avoid much more costly issues in the future. During a root collar inspection, an arborist is able to determine if the tree was planted too deeply, to diagnose root rot or existing root injuries, and to remove girdling roots. At construction sites — before or after you build that addition to your home — the process makes it possible to properly prune roots that are at risk of being damaged, to install utilities around roots, and to relieve soil compaction.
It’s amazing how much can be accomplished when you can actually see the task at hand!