- Tree roots are shallow. (Image 1)
- Ninety percent of the fine, water- and mineral-absorbing roots of a tree are in the
upper six to twelve inches of soil. Piling soil over a root system or increasing a
soil grade can smother roots. Cutting or removing too many roots is also harmful.
(Image 1)
- Tree roots are extensive and go 2 to 3 times past the canopy drip line. (Image 1)
- Severed roots even if it is just one major root can add up to a tree loosing 5 to
20 percent of its entire root system.
- Boring when applicable in lieu of traditional trenches can save tree roots and help
assure healthier, longer-lived trees in the landscape. (Image 2)
- Physical injury to the trunk, limbs, and branches can lead to disease and decay. (Image
3)
- The ability to repair construction damage to trees is ineffective. The single most
important action OSU can take is tree protection.
- Barriers with fence panels will be constructed to keep tree roots and trunks protected.
The area will be known as the “Tree Protection Root Zone”. The fence barriers must
be installed as directed prior to any equipment arrival to the site. (Image 4)
- The fence should be placed to allow for a protected root zone of 1 to 1.5 foot of
space from the trunk for each inch of trunk diameter measured 4.5 ft. from the ground.
A twelve-inch tree needs a twelve-foot diameter fenced off area around the trunk.
- The fence protects the arial parts of the tree as well as the underground root system.
Construction traffic causes soil compaction and be detrimental to the root system.
(Image 5)
- Soil compaction caused by increased foot traffic and heavy machinery decreases soil
oxygen and water pores, inhibiting root penetration and resulting in tree health decline.
- Construction personnel must remain off limits in the fenced areas and keep the area
clear of building materials, waste, excess soil, and porta potties. No trenching or
other soil disturbances should be allowed in the fenced areas. The fence must not
be moved during construction.
- Site clearing by adding or grading away soil, damages tree roots causing lasting negative
impacts even death.
- Construction site visits will occur by FMLS staff to evaluate the tree protection
efforts.
- TREE Protection will be strictly enforced as noted on the bid and contract documents.
Work will be stopped and fines assessed should guidelines not be practiced or damage
occurs.
Full OSU Tree Care Plan and Standards
