GRCAPruningGuideline_20140909_0001.pdf

Grand Canyon National Park Pruning Protocols

Authority Information contained in this brochure was adapted from the International Society of Arboriculture’s (www.ISA-ARBOR.com) Best Management Practices on Tree Health and Pruning and National Park Service Management Policies.

Grand Canyon Contact Information Hazard Tree Coordinator:

Phone: (928) 638-7617

Vegetation Program Manager:

Lori_Makarick@nps.gov Phone: (928) 638-7455

Fax: (928) 638-7492

1/9/2014

1. Do you have authority to cut? Check with your supervisor that you have approval. Be sure this is part of your job and you have the proper training, the right tools, the appropriate PPE, and that you understand all potential site hazards. Make safety a priority.

2. Is cutting necessary? How will this benefit the tree? human safety? Think before you cut.

Work with the vegetation and avoid pruning whenever possible. Every cut you make could change the growth of the tree. Never prune more than 20% of the total canopy (the green leaf or needle-bearing area of branches).

3. Time of year dictates when pruning is performed. Depending on plant species , growth habit, region, and insect and disease life cycles, consult with a professional on the best time to prune to encourage plant health and achieve the best aesthetic result.

4. Proper technique is essential. Poor pruning causes damage that lasts for the life of the tree. Know where to cut and make clean cuts.

5. Trees do not heal the way people do. When a tree is cut (wounded), it must grow over and compartmentalize the wound. Improper cuts can lead to tissue death, cracks, decay, and insect and disease infestations.

6. Smalls cuts damage a tree less than large cuts. Avoid removing large branch sections first. Start by removing smaller sections of the branch; more can be removed if required.

Small cuts heal more quickly than large cuts. If you think a tree will need pruning in the future, prune the tree now when it is young.

7. Sharp and sanitized tool edges produce clean cuts. Sharp, clean tools minimize wound surface area and reduce the potential of transferring harmful plant pathogens.

When plants are pruned properly, they are more likely to thrive. Improper or excessive pruning harms plant health and structure. Wounds encourage forest and insect disease and shorten the plant’s life span. Prune prudently and only remove branches that threaten safety or negatively impact infrastructure. You are responsible for being a good steward of park lands– learn the protocols in this brochure and take care of our trees.

Why prune?

Pruning is done to reduce hazards, provide safe or adequate structure clearance, correct storm-damaged wounds, and enhance the structure and health of the tree.

When is pruning permitted?

Pruning is permitted only when it is covered under an approved park management project with current compliance, which includes inter-divisional review.

Who is authorized to prune?

Only employees or workers with proper training and authorization from Grand Canyon National Park managers are allowed to prune vegetation.

All personnel pruning vegetation must review the appropriate JHAs and wear required PPE.

Who is NOT authorized to prune?

• Residents

• Visitors/Hikers/Campers

• Tour Guides/Bus Drivers

• Employees that do not have training or do not have pruning listed in their position description and scope of duties

Think before you cut! “The location of the pruning cut is the most important aspect of pruning. The location of the cut influences growth and minimizes the length of time required to callus (heal).”

-Dr. Alex Shigo, PhD, “Father of Modern Arboriculture” Biologist & Plant Pathologist for

USFS

Proper pruning removes an unwanted branch at its attachment point to the trunk or another branch.

This is the branch collar.

Branch Bark Ridge – area of a branch crotch where growth and development of the limb push the bark into a ridge shape.

Branch collar – “shoulder” area where a branch joins another branch or trunk created by the overlapping xylem tissues.

Where to Cut?

Required Cutting

Method:

Root Pruning & Care

A tree‘s roots should be pruned if they are exposed during a project. It is important for tree survival to not remove more than 33% of a tree’s roots and not remove more than 20% from one side.

• Roots tend to be flexible. The best tools for root pruning are sharp loppers, shears, or pruners. The quick slicing action of these tools makes cleaner cuts than saws, which tend to shred and fray pliable roots. Only use saws if roots are stiff and woody and if root diameter exceeds the size of available pruners and shears.

• Sanitize tools with bleach to prevent the spread of fungus or disease, and maintain sharp blades to avoid frayed cuts.

• Cut exposed and frayed roots cleanly after excavation to promote wound closure and prevent the spread of disease. Sharp, clean cutting edges make cutting easier and minimize wound surface area.

• Roots may be damaged by mechanical impact (i.e. trenching), changes in hydrology, and compaction of soil by machinery, vehicles, and foot traffic. Soil compaction inhibits root growth, reduces soil aeration and water infiltration, thereby “suffocating” the tree. Root damage, infection, and decay cause 75% of tree failures.

Branch Bark Ridge

Branch Collar

Always sharpen the cutting edge of your tool to prevent frayed cuts and make cutting easier

1. Undercut below the limb away from the branch collar. This eliminates the chance of bark peeling from the trunk.

2. Top cut farther out (one to two inches) from the undercut to remove the branch. This cut will leave a stub.

3. Complete final collar cut clean and smooth.

This cut removes the branch stub.

INCORRECT! Do not leave stubs

Flush cuts against the main stem leave a large wound and do not close well. They are a major contributor to decay in trees.

INCORRECT! Do not flush cut branches

Proper cut location at the branch collar. The branch collar remains intact.

CORRECT!

Proper final cut at branch collar

Typical root mass of a tree in relation to canopy drip line.

This cut will leave a stub or result in weak stem attachments of new branch growth.

CORRECT: Branch collar remains intact.

INCORRECT: Flush cut removes the branch collar.