Trees require water as well as oxygen in the soil in order to maintain healthy growth. Construction activity (driving or parking vehicles, staging of materials, grading the soil, etc. under or around trees) compresses the soil, limiting the amount of pore space between the soil particles. The very fine roots of trees that are responsible for absorbing water, nutrients and oxygen grow in these tiny pore spaces between soil particles.
These types of construction activities not only damage the soil structure but also can crush and kill the fines roots. The purpose of this treatment is to loosen and aerify the soil, recreating the soil conditions conducive to the regrowth of the damaged roots and speeding the tree’s recovery. Because trees store energy, the effects of construction damage to the root zone often do not become apparent for a number of years. Often by the time damage is apparent in the canopy of the tree, it is too late to reverse the decline of the tree and the tree eventually dies.
Soil aerification /decompaction involves taking up the sod over the root area in long narrow trenches (or sometimes as pie-shaped wedges) radiating out from the stem of the tree to the edge of the canopy. Compressed air is then used to loosen the soil around the existing root system. Often times compost and/or organic-based fertilizer is added to enhance the existing soil structure and encourage redevelopment of the root system. The sod that was removed is then re-laid over the trenches.