Tree protection zones – why we need them Prior to commencing with any construction activity on your property it is important that you consult with an ISA Certified Arborist or Consulting Arborist determine the type and condition of the trees on your property and surrounding properties and to become aware of the tree protection by-laws that could impact your proposal. During construction project there are typically three types of injury that can occur, and knowing the proper and adequate protection for each is important. Physical Injury: This is damage to the main stem or branches of a tree, and typically is mechanical damage caused by large equipment on site. Root Cutting: This can impact tree health both short and long term, and many contractors and architects do not understand the risks to the tree health. In fact it has now been proven that many trees which were attempted to be saved in the project goals were seriously compromised. See our article on root disease or root rot – as many construction damages cause issues only seen 10 or 20 years later. It should be noted that the majority of roots are in the upper 30 to 60 cm of soil, and any work within that soil area is injurious to the tree and potentially can put the trees survival at risk. When working around root areas, it may be necessary to locate an Arborist who has a specialised tool called an “Air Spade” to perform the work for you, this tool allows for non-intrusive excavation. Compaction: one of the leading causes of tree decline in the urban area is soil compaction. Compaction occurs from vehicles and equipment moving across the root zone, packing the soil and preventing the passage of moisture or oxygen to the root zone. Without this ability for moisture and air to move, the roots smother and essentially die. This same effect can also be caused by adding a few inches of soil over the root zone. Protecting trees on your property The best thing you can do is find an ISA Certified Arborist to help with your project. A professional can better advise you on the protection required now, and the long term maintenance. See why do I need an arborist article for further information. The hiring of an ISA Certified Arborist is the 1st thing you should do. They will take an inventory, plot this information on a computer and work with you to develop a plan that works. This involves the development of a “Tree Protection Zone” during the actual project timeframe, and monitoring of trees during entire project.
Minimum Tree Protection Zones – Note these should be expanded for some species. Diameter at 140 cm Minimum protection Less than 10 cm 1.2m 10 – 29 cm 1.8 m 30 – 40 cm 2.4 m 41 – 50 cm 3.0 m 51 – 60 cm 3.6 m 61 – 70 cm 4.2 m 71 – 80 cm 4.8 m 81 – 90 cm 5.4 m 91 – 100 cm 6.0 m Over 100 cm 6 cm for each 1 cm diameter
An ISA Certified Arborist can also help you to design the necessary protection fence, usually out of plywood, but always out of something sufficient to keep equipment and materials out of the zone area. Within the tree protection zone there can be no: Construction Altering of grade by adding fill, excavating, trenching, scraping, dumping or any type of disturbance Storage of equipment, soil, materials, waste, debris or liquids Disposal of any materials, including but not limited to concrete sleuth, gasoline, oil or paint Movement of vehicles, pedestrians or equipment of any kind Parking of vehicles or machinery Note: Directional tunneling or boring may be permitted if approval is obtained Note: open face cuts outside of tree protection zone are required, however they may require root pruning done by an ISA Certified Arborist. Digging by a air spade or hydro vac may be necessary as well during this process. Call us for further information: Simcoe Muskoka Tree Services Inc. www.simcoemuskokatreeservices.ca