Did You Take the Right Photo?

I receive inquiries about tree failures from attorneys, insurers, HOA’s, commercial and residential property owners.  Unfortunately, many inquiries concern a failure that already occurred, resulting in personal injury, property damage or both.  Potential legal clients want to know the cause of the failure and whether the Owner or contractor satisfied the standard of care.

Forensic investigation to determine the cause of a tree failure may be difficult.  Whether a limb or whole tree failure, the tree is usually removed and the accident site cleaned in a short period of time.  Without actual evidence of the failed part to examine, determining the cause of the failure is impossible.  Or is it?

If the Client took effective photographs of the tree failure at the time of the accident or shortly thereafter, a skilled arborist might be able to examine the failure for clues that could determine it’s cause.  Unfortunately, most people take pictures that have limited or no value for forensic analysis.

Whole tree failure due to root disease. (Photo by JoeLaForest)

Failure due to root disease. (Photo by JoeLaForest)

There are several types of failures to distinguish.

Root failures, usually due to a root rotting fungus, resulting in loss of anchorage, entire tree failure may occur, particularly during inclement weather. Blackened broken off roots may protrude out of grade.

 

Soil failure, the entire root ball rotates or heaves out of grade, typically occurs during wet, windy weather. In a soil failure, root protrusion from the soil mass is limited.

Soil failure resulted in tree loss.

Soil failure resulted in tree loss.

 

Collar and basal stem injuries may result in the tree snapping off at the base.  Collar injuries may occur from mechanical sources, such as string trimmers, mowers, or edgers.  Trees grown in small, confined planters, such as cutouts in sidewalk may develop girdling roots resulting in poor root development and anchorage.

Restricted root zone results in collar failures

Restricted root zone results in collar failures

Within five years, tree trunk diameter may outgrow the opening within a tree grate.  Construction activities that raise or lower the grade may also damage the root collar and surrounding surface roots.

Trunk failures may occur due to co-dominant trunks, two trunks of equal size sharing the same attachment.  Co-dominant trunks may develop included bark, which weakens the trunk attachment, resulting in the trunk cracking or completing splitting apart along the weakened plane of included bark.

Co-dominant stems crack. (by Cherokee Tree Care).

Co-dominant stems crack. (by Cherokee Tree Care).

Limb failures are perhaps the most common type of failure. Limbs may drop for a number of reasons.  Typically, limbs fail due to weak attachments to the other larger limbs or the trunk.  Multiple limbs attached at the same point, poor architecture, excess load, cracks, and cankers inevitably start to decay.  As the decay decreases the structural stability of the attachment, the limb is susceptible to breakage or detachment from the tree, typically during inclement weather events.

Weak limb attachments. (by Randy Cyr)

Weak limb attachments. (by Randy Cyr)

However, sudden and summer limb drop are syndromes whereby healthy limb failure occurs during calm weather, usually May-October.  The syndrome is still not fully understood or how to manage.

Although not a tree failure, surface roots may be responsible for damaging infrastructure, particularly lifting and cracking concrete sidewalks and patios, a major source of trip, slip and fall accidents.

Roots lifted sidewalk

Roots lifted sidewalk

 

Sidewalk replacement due to root damage

Sidewalk replacement due to root damage

As roots age, they increase in diameter, just like a branch or trunk.  As roots grow under a sidewalk age, they increase in diameter, slowing lifting sidewalk panels over time.

Trees typically fail suddenly,with little warning.  The resulting impact may cause extraordinary property damage and possible personal injury or death.  When an event occurs, emergency workers, media and the public are focused on the event, saving life or restoring traffic, not on taking forensic photographs of the accident.

By SD Union Tribune

Emergency crews at work. (by SD Union Tribune)

Forensic reconstruction of a tree failure relies upon factual evidence.  If the failed tree or limb has been disposed, it is impossible to assess why the failure occurred unless well taken photographs exist.  If a tree limb fell due to a cavity or defect, photographs showing the limb lying on the ground are of limited value.

Forensic photographs should depict the condition of the failed limb or whole tree.  While a photo of the limb lying on the ground adds some context, it does not depict the cause of the failure.

Limb failed due to an old decaying canker.

Limb failed due to an old decaying canker.

Photographs should show the end of limb that broke off the tree and the scar or injury left on the tree trunk. Sometimes, it takes a long time for a limb canker to decay. Over time, the decay weakens the attachment of the limb which eventually fails.  A photo showing the broken end of the limb and the damaged trunk area could prove invaluable.

Considerations for effective forensic tree failure photographs:

  • Timing:
    • Take as soon as possible from date of the accident.
    • Take photographs of changes in condition, ie:  the tree stump remained one day but was removed a week later.
    • If case extends over time, take photographs over the time period, this may help establish original tree wounds and healing rate.
    • If using a digital device, turn on the date stamp for photographs.
  • Include Photographs of The Site:
    • Establish the overall accident perspective with wide angle photographs depicting the entire site, street, park etc.
    • Overhead or underground utilities, adjacent structures, construction activity.
    • The presence of irrigation system.
    • Damp, wet, moist, standing water conditions.
    • Planter size, confined by curb, gutter, sidewalks, asphalt paving, driveways or other obstructions.
    • Grade condition, accumulation of tree litter, mulch or compost placed around tree trunk and roots.
    • Add a tape measure for scale
  • Include Photographs of the Subject Tree or Part:
    • The entire tree or limb from one end to the other.
    • Surrounding trees of same species for comparison.
    • The broken end of the limb
    • The  torn, damaged area on the trunk the limb detached from.
    • The root condition.
    • The planter or turf area the tree was growing within.
    • The soil conditions.
    • Add tape measurements for scale and dimensions.

Tree failures occur infrequently, but when a failure occurs, consequences may be severe. The first reaction of emergency responders and the general public is to assist in an emergency, not document the cause.  Since most tree failures are cleaned up and removed within a short period of time after the accident, valuable forensic evidence may be lost.

Photographs shown in this blog show the location of the failure, not the end result of the failure.  Effective forensic photography should depict the failed tree component(s), including trunk scars, injuries, failed or torn limb ends.  Tape measurements included in the photograph may prove very helpful.

When the tree or limb has been cut up and hauled to the landfill, the only effective evidence might be photographs taken at the time of the accident that depict defects that might establish the cause of a failure.  An arborists requires evidence and facts to assess why a tree failed.  Well taken photographs are often the most effective forensic tool available for analysis.  So, take the right picture!

Spring Madness

The beauty of spring is all around us, take a moment to enjoy it.  Take a walk through any of our coastal canyons, parks and open spaces.  You’ll be rewarded!

Not a field of poppies but still...

Not a field of poppies but still…

Wow

Wow

Get out there!

Get out there!

One of the Best Flowering Trees!

Back in my college days at Cal Poly Pomona, I took several plant identification courses as part of the educational requirements for Ornamental Horticulture.  Two trees from the same genus always stood out for their outstanding floral display and landscape use.  Back then, the genus was called Tabebuia, since changed to Handroanthus. The two useful landscape species are Handroanthus impetiginosa,(Pink trumpet tree) and H. chrysotrichus, (Golden trumpet tree).

The Pink trumpet tree in full bloom

While taking a walk, I came across a beautiful pink trumpet tree in full bloom.  I then started noticing a few other trumpet trees scattered about the neighborhoods in North Park.  I’m not to sure why, but in my view, this species is an under utilized ornamental landscape tree.  Perhaps due to a slow growth rate, medium appetite for water or its deciduous nature, the species is not heavily promoted by the nursery industry.  But it has many beneficial characteristics making it a useful ornamental landscape tree.

The pink trumpet tree requires full sunlight to part shade and grows to approximately 25-feet in height in Southern California.  The non-aggressive rooting system makes it a good choice for use in smaller confined planter areas such as a parkway strip.  It performs well in the urban environment.  Like most trees, it prefers well drained fertile soils however I see this tree flourishing under less than ideal conditions.  No noted pests or disease, hardy to 24º F, damaged below 18º F.  After spring flowering, it grows a green to brown colored pod.

A close relative to the pink trumpet tree but faster growing

A close relative to the pink trumpet tree but faster growing.  By M.Ritter, W. Mark, J. Reimer, C. Stubler

Unlike the pink trumpet tree, the closely relate golden trumpet tree is a more rapid, larger growing tree.  It too is deciduous, and like the pink trumpet, it flowers in the spring with an impressive display of brilliant, fragrant yellow trumpet flowers.

This tree grows to a larger size than the pink trumpet, up to 50-feet tall and similar width.  It has a spreading, low canopy that matures into a broad, round-headed or vase shaped crown.  It prefers full sun to part shade.

Branch strength is rated as medium to somewhat weak and root growth is more aggressive than the pink trumpet.  Unlike the pink trumpet, the golden trumpet tree should not be used in a confined planter are.

Both these trees perform well in our mediterranean climate and their different growth characteristics allow for varied use,  one in more confined areas, the other requires more room to grow.  Once established, both are relatively drought tolerant.

Hope you find this helpful, let me know if you have any questions!

 

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Worried About Your Tree?

We have gone from record drought to record amounts of snow and rain throughout California.  While the winter storms have wreaked havoc on our infra-structure (Oroville dam spillway, flooding in San Jose, etc, they have been a blessing for drought starved trees throughout the west.  Years of inadequate rainfall reduced soil moisture leading to an incredible dieback of trees numbering over tens of millions within the state.

The urban environment creates stresses not normally encountered in the wild.  In cities and suburbs, trees contend with confined planter area, compacted soils, improper or inadequate irrigation, poor maintenance practices, improper pruning, shading by homes or buildings.   Stresses created by the urban environment reduce tree life expectancy, sometimes by as much as 50%.

During the drought, I have seen an increase in tree failure, whether a limb drop or whole tree failure.  In most instances, crown, limbs, branch and twig dieback were the obvious symptoms of the drought.  Many times, clients mistakenly thought the dieback was caused by disease or insect, however root dieback from minimal soil moisture was the cause of crown dieback.

Now, with the heavy rainfall and wind, tree failure due to saturated soils are on the increase.  Trees remain upright due to their root system.  Structural and buttress roots grow outward from the trunk at the (root crown), out to the edge of the crown (known as the dripline).  At the dripline, the structural roots are 1-2″ in diameter.  They continue to grow outward, branching into the small, fine feeder roots that absorb moisture and nutrients.  Depending on local conditions, tree roots may extend 1.5 times the tree crown diameter.  Based on San Diego soil conditions, most roots grow within the upper three feet, typically 80% of the roots are within the top 18-24″ of the soil.

Roots in dry soil are held in place by friction.  However, when rain saturates the ground, it acts as a lubricant, lessening the soil friction holding roots in place.  When wind combines with excess weight from rain or snow, the energy is transmitted down the trunk to the roots.  Soil root friction reduced by saturation causes roots to loose anchorage, resulting in a failure.  When roots fail to support the tree, it is assessed as a root failure.  When the entire root ball rotates up from the soil, it is a soil failure.

Homeowners with large trees in close proximity to their property should examine their trees for any change in condition as a warning sign of a potential problem.  Changes to be aware of include:

  • Is the tree leaning?
  • Are there soil cracks at the base of the tree?
  • Is the soil lifting, tilting or rippling at the tree base?
  • Are there dead limbs or branches in the crown?
  • Is there a progression of twig, branch and limb dieback?
  • Did the tree drop it’s leaves abnormally early?
  • Did the tree not leaf out as in the past?
  • Any obvious open cavities, cracks or splits?
  • Any animals or insects nesting within a hollow, cavity or crack?
  • Any fluids, abnormal sap flow or other discharges from the tree?
  • Has irrigation been reduced or eliminated to the tree?
  • Has there been construction activity near the tree?
  • Have the roots been disturbed by any nearby utility or sidewalk work?
  • Is the tree sitting in water, is there proper drainage?
  • Has there been a change in grade near the tree?

If you can say yes to any of the above, your tree may have acquired defects that increase the risk of failure.  The increased risk of failure may result in property damage or personal injury to your family, friends, or any pedestrian near the tree.  A tree with a history of previous failures possesses an increased risk of failing.  Trees may not present any obvious signs or symptoms of a defect.  Unseen decay may exist within a limb or trunk, or as a root rot.

Whether commercial or residential property, if you are concerned about the health and safety of your trees, you should contact an arborist certified by the International Society of Arboriculture, (ISA).  Once certified, the ISA allows arborists to enroll in specialized training to earn the credential of a Tree Risk Assessor Qualified.  While anyone may attempt to assess the health and structural integrity of a tree, certified arborists who are qualified in tree risk assessment represent the industry standard and best management practice for tree risk assessment.

Tree risk assessment is the current best management practice to determine tree risk of failure associated with defects.  The assessment utilizes a level two basic visual assessment and a two page ISA format for the assessment protocol.  The assessor may determine more advanced assessment techniques are required, however usually a basic visual assessment will suffice.

If you have noticed a change in the health or condition of your tree, take proactive measures before a catastrophic accident, call a certified arborist knowledgeable in tree risk assessment.

Click here to read an article published in the LA Times Risk Assessment article.

What is an RCA?

When I tell people I’m a consulting arborist they often ask what is that? Everyone is familiar with tree care companies, but not so much what the role of a consulting arborist. The common conception is when there is a tree problem, call up a tree contractor and have them do the work.

Yet, there are many tree problems that require expertise beyond a tree care company. When a tree has a change in condition or conflicts with infrastructure, a consulting arborist is required to assess the situation and make recommendations.

Consulting arborists have one or more certifications.  The primary designation is a certified arborist.  This designation is administered through the International Society of Arboriculture (ISA).  The second and more difficult designation to obtain is that of Registered Consulting Arborist (RCA), administered through the American Society of Consulting Arborists (ASCA). Consulting arborists with the RCA designation are the preeminent authorities on tree related matters.

To receive the RCA designation, an individual must already be a certified arborist.  Once they meet the experience and education requirements, an applicant must enroll in the Consulting Academy.  This rigorous training focuses on technical and report writing. Applicants who receive their RCA designation are trained to produce the highest quality written reports and work product, a terrific benefit for attorneys, insurers and professional consultants.

To learn more about registered consulting arborists, please click on the link below.

What is an RCA

Landscape and Tree Contractors, Minimize Lawsuits, Understand Your Duty of Care!

If you are a landscape or tree care contractor, you should be aware of the potential liability you face by an unhappy client. This awareness begins when you understand your “duty of care” as a landscape or tree care professional.

What is “duty of care”? It is a very important legal concept that simply stated means a person or organization has the legal obligation to avoid acts or omissions that could harm others. The duty of care extends to your actions or lack of action that would cause harm to your client or their property, perhaps even extending to adjacent properties and utilities.

Licensed contractors should understand their client hired them for their expertise and professionalism. The client is reliant upon the contractor to provide a product and service that conforms to industry standards. It is incumbent upon the contractor to satisfy all contractual obligations and satisfy the industry standard of care, or face a possible lawsuit.

If you are a landscape, maintenance or tree contractor interested in learning how to minimize you legal exposure and reduce your liability, please read the full article at:

Reduce Liability by Understanding Your Duty of Care