EXTENSION REPORT

Preparing and Restoring our Urban Forest for Storms

Storms are a way of life in Alabama, somewhere each year, a natural disaster will occur and change forever the face of a city, town, community, or neighborhood.  No person or place is immune. 

Urban forests are also a way of life in Alabama.  Our cities and towns have more urban trees than any other state except Georgia.  Yet when storms and urban trees collide, the results can be severe.  Storm-damaged trees may topple over or break apart. The results can be clogged streets, disrupted utility service, damaged property, and a threat to public safety.  No matter what our opinions are about urban trees, we learn that nature’s forces can turn unmanaged and ignored trees into a problem for both people and the places they live. 

How to prepare and repair trees after storms?

Following a major storm or hurricane, impacted trees need immediate attention and care.  High winds, ample rain, and lightning can cause a variety of problems in trees.  Storm damage can impact the entire tree, trunk, limbs, roots, and in many cases lead to the eventual decline and mortality of the tree.  In an effort to improve the health and safety of trees it is important to conduct thorough assessment before and after storms. 

An urban tree assessment is the process of thoroughly inspecting a tree for signs of damage that might cause safety risks and impact tree health and survivability.  Assessments provide the homeowner with the knowledge necessary for developing a management course to improve the safety and health of trees in the urban forest. It is important to conduct an assessment in the months before and after hurricanes to remediate any problems that high winds will cause. 

Conducting the Assessment

Several factors must be considered and information collected to ensure right decisions are made.  Whether you will be repairing trees yourself or hiring a professional arborist, the following information must be collected:

Tree species:  Noting tree species is important because some trees are more problem prone and may have characteristics that aren’t worth the effort. 

Location:Describe if the tree is near any “targets” (i.e. structures, power lines) that it could damage. Depending, if a tree is near potential targets, impacts management considerations.  It may not be wise to attempt and preserve a dangerous tree that could damage valuable property or impact public safety.

Tree Condition:  Determine the tree ’s health, condition, and risk to people, property, and places before making an informed decision whether to repair or remove the tree.

Assessing Tree Condition

It is important to view the tree first from a distance and then from several different angles.  This will help you identity any leans and is the best vantage point for estimating percentage of lost limbs and foliage.  After a thorough walk around, move in closer and closely examine the trunk, major limbs, and roots system for problems.

1.  Assessing the Main Stem or Trunk

The trunk of the tree is the primary stem between the roots and the limbs and foliage above.  The trunk conducts water and nutrients while supporting the total above ground weight of the tree. Trunk damage can be exceedingly dangerous and damaging to the health of the tree.

Start by carefully walking around the tree looking for cracks, twisted wood, torn or ripped bark, or breaks.  Note the severity of the damage to provide the proper management technique.  Below is a chart to help quantify damage and to determine management actions. 

Broken, Cracked or Twisted Trunk:

                Source: http://www.treesafterthestorm.org/

2.  Assessing Branches

Most branch damage will be obvious at a glance.  However, it is important to look at branches from all angles.  Assess your larger branches first, because of their potential for the greatest danger to people.  Look for cracks, torn or twisted bark and branches pointing at odd irregular angles.  For a detailed assessment, an ISA Certified Arborist ia needed to climb and inspect the tree more closely.  Some damage may only be visible from above.

Source: http://www.treesafterthestorm.org/.

3.  Assessing the Roots

Roots are often ignored because damage below ground is less visible.  Roots provide two primary functions in trees.  They anchor the tree. They also absorb water and nutrient.  When roots are damaged trees will have a reduced capacity to support the needs of the tree canopy.   This structural loss of stability increases a tree’s risk hazard for failure.

When assessing roots carefully inspect the soil around your tree.  Look for recently exposed roots.  In the case of leaning trees a raise hump in the soil on the back side of the tree combined with  a soil indentation on the inside of the lean  will indicate that there is likely to be broken roots which can lead to future tree failure.  Hiring a consulting or ISA Certified Arborist is advised.

Inspect the soil for damage and estimate the percentage of the ground surface that appears damaged.  It is important to note that roots will often extend twice as far as a tree’ s branches.  When damage occurs inside the tree’s drip-line, or furthermost branches, the tree must be closely monitored because there is likely substantial root damage.  Use the bellow chart for a rough guide:

Source: http://www.treesafterthestorm.org/ 

After some major storms you may encounter leaning trees.  Trees that are leaning may have broken roots and may need to be removed.  There are two questions you should consider when assessing your lean.  First, did the tree lean before the storm? And second has the lean increased substantially?  Just because a tree is leaning it doesn’t mean you have a hazardous tree.  However, leans caused by high winds must be assessed for failure potent ial.  Use the chart below to quantify your lean and derive a recommended management:

Source: http://www.treesafterthestorm.org/ 

Hiring an Arborist

After a storm, it is advisable to hire a professional arborist to help repair and remove damaged trees.  Always hire qualified arborists, with the latest information and techniques for quality work.  Remember you don’t take your dog to an untrained veterinarian or go to an unlicensed dentist, tree are living and also need a professional eye.  When contracting an arborist look for the following qualifications and information to be provided:

Minimum qualifications for professional tree care worker

Bonded

Insured – Ask to see proof

List of references - Be specific!

Detailed work plan and cost estimate in writing

Expected dates of work

International Society of Arboriculture (ISA) Certified Arborist

For additional information contact Beau Brodbeck at the Baldwin County Extension Office in Bay Minette Alabama by email at brodbam@auburn.edu or by phone at 251-937-7176.

Email address: brodbam@auburn.edu
Phone: 937-7176 or 943-5611, ext. 2222

Issued in furtherance of Cooperative Extension work in agriculture and home economics, Acts of May 8 and June 30, 1914, and other related acts, in cooperation with the U.S. Department of Agriculture. The Alabama Cooperative Extension System (Alabama A&M University and Auburn University) offers educational programs, materials, and equal opportunity employment to all people without regard to race, color, national origin, religion, sex, age, veteran status, or disability.