The large beech tree in the right of this photo is as sensitive as the skin of a newborn baby. We didn't allow any trucks or equipment within its drip line.
DEAR TIM: We built our home on a wooded lot 4 years ago. Within the past 6 months over 50 percent of the trees on our lot have died. Several other trees appear unhealthy. I seem to remember that the excess dirt from the excavation was spread around the lot. My builder confirmed this and added that this is a common practice. Could this have caused the problem? Is there anything I could have done to save my trees? R.C.
DEAR R. C.: Your builder should be arraigned and charged with involuntary tree slaughter. The spreading of excess dirt could very likely have been the main factor in the death and sickness of your trees. There is a strong possibility that other construction events hurt your trees as well.
The root systems of trees can be severely damaged by construction activities. Soil compaction is one of the biggest problems. Prior to construction, the undisturbed top soil on your lot contained vast amounts of oxygen. The trees use this oxygen when they extract nutrients from the soil. Excavation equipment, concrete trucks, delivery trucks, even light pickup trucks squeeze this oxygen out of the soil. Soil compaction affects soil moisture content. Rain water is more likely to runoff than be absorbed. Soils containing high amounts of clay compact more readily than sandy soils.
In your case, the extra excavation dirt was the kiss of death. There is no doubt that the soil was compacted beneath the trees, as the loader or dump trucks had to drive beneath the trees to dump the dirt. This extra soil then made it virtually impossible for air and water to get to the buried tree roots.
Shallow trenching and excavating activities can cut into root systems. A majority of tree roots are in the top 2 - 3 feet of soil. Tree root systems serve two primary functions. They provide the nutrients and moisture for the tree and also act as an energy storehouse. Root systems are a two way street. Nutrients and water from the soil are transported by the roots, up through the tree, and into the leaves. The leaves are miniature factories. They transform the nutrients and water into energy, some of which is sent back down the tree into the roots. This energy is used each spring to produce leaves and seeds.
Your soil chemistry may have changed as well. It is possible that some of your trees died because the soil pH level became too alkaline. The most common causes of this result from the washout of concrete trucks and bricklayer's mortar mixers. Burying scrap drywall also can change soil chemistry.
If you could go back in time, you should have hired a certified arborist. This individual would most likely have developed a plan to protect all of your trees before the first shovelful of dirt was turned.
Secure fencing would have been placed around all trees that required protection. Financial penalties could have been included in contracts for any workman who violated a fenced area.
A system of aeration and watering pipes could have been placed beneath the soil which was placed over the tree roots. An arborist could have saved your trees. My wife was smart enough to call one years ago, before we built our house. Every tree on our lot is alive and healthy.
This is my own home. The large trees were on the lot before I started. They are in perfect health because I listened to Kathy my wife. She insisted we call in a certified arborist to tell us what to do.
