Why are Humans Blind to Understanding Trees?

I watched a terrific webinar hosted by Mr. Neville Fay, an gifted, learned arborist in England. Here are some takeaways from the Webinar.

Humans identify with other living animals because humans are animals. anthropomorphism, the interpretation of nonhuman things or events in terms of human characteristics, as when one senses malice in a computer or hears human voices in the wind. Anthropomorphism is a human characteristic hindering are ability to fully comprehend and understand the plant kingdom, particularly trees and plants.

Why are humans blind to the plant kingdom? Is it because humans have become increasingly separated from nature? Since we are a part of nature, indeed we came into existence in nature, what happens when we separate ourselves from nature, if we become alienated from nature are we alienated from our own self?

Our language and thoughts create and limit our world and influences our opinions. “The tree which moves some to tears of joy is, in the eyes of others, a green thing that stands in the way”. Our language limits how we think, how we view the world, and explains why we cannot fully understand and appreciate trees.

We often define a tree based on its location, aesthetics, function or monetary value. Trees in forests are viewed for the timber value. Old, mature, dying trees are viewed as dangerous threats to our well being. Trees life expectancy is often viewed from a “useful” perspective, usually resulting in damage, flawed or senescent trees being removed rather than allowed to progress through their lifespan? This may make sense in the urban environment, but what happens when a supposedly dying or dangerous tree is allowed to continue living beyond its “useful” lifespan?

These trees defy our attempts at defining what a tree is. They are remarkable living beings that have the ability to define or refine what a tree is, can or should be. Every tree pictured above has retrenched itself into a new being, growing new tree parts or new trees from original broken or decayed stems and trunks. Obviously they have no timber value, but appreciating there ability to survive and recreate is very inspirational.

Trees have several life stages, young to early mature, full to late maturity, ancient and or sessile. We frequently never allow trees to exist in their ancient life stage, especially in the urban environment.

As trees enter the ancient life stage, they undergo crown and root retrenchment, dramatically increasing their functional complexity and reiteration.

Here is an ancient olive tree, a tree completely hollowed out, the original trunk is gone, yet it has drawn upon resources to interweave multiple stems and roots into a retrenched healthy olive tree. Is this one tree or multiple trees or even a forest of trees? This tree has no timber value, and would most likely never be allowed to exist in an urban setting. Yet It can only be viewed as awe inspiring, magnificent.

While trees are a part of ecosystems, a single mature or ancient tree is in and of itself a complete ecosystem, supporting an abundance of animal, bird, insect, fungal and bacterial life.

Did plants and animals evolve from a single source? A theory called Endosymbiosis posits plants and animals evolved from the same original source. The Endosymbiotic Theory states that the mitochondria and chloroplast in eukaryotic cells were once aerobic bacteria (prokaryote) that were ingested by a large anaerobic bacteria (prokaryote). This theory explains the origin of eukaryotic cells.https://bio.libretexts.org/Bookshelves/Microbiology/Microbiology_(Kaiser)/Unit_4%3A_Eukaryotic_Microorganisms_and_Viruses/07%3A_The_Eukaryotic_Cell/7.8%3A_The_Endosymbiotic_Theory

The separation between animal and plant cells diverged when mitochondria evolved from bacteria evolving into animals versus chloroplasts developing from bacteria evolving into algae and plants. Records depict trees have lived and evolved with humans for thousands of years. Their existence and importance to humans cannot be overestimated.

Trees cannot escape where they grow, they become soil farmers, they are conductors of the soil orchestra of microorganisms. Soil is alive, a living breathing thing. Where trees are allowed to flourish, they enrich soils, thereby creating the endless cycle of life. When we develop and compact soils, we are killing a living environment. Mega agribusiness utilizes monocropping to produce our food, a practice that increases their profit while killing off biodiversity and depleting our soil resources. https://www.greenmatters.com/p/what-is-monocropping

Leonardo de Vinci understood the complexity of trees and their roots, positing the root structure being a mirror image of above grade stems and limbs.

Soil compaction is the single greatest threat to soils, thereby our future.

We need to embrace trees, eliminate bias views of trees based on our own anthropomorphic views. We cannot exist without trees, they provide the oxygen for our planet, without trees, humans would not survive. And even if somehow we managed to survive, I for one could not imagine a world without trees.

Tree Roots Lifting up Sidewalk?

Who is Better Qualified to Opine on Root Damage, Civil Engineer or Certified Arborist?

I was retained by a defendant attorney to determine whether her client’s tree was responsible for lifting the adjacent civil sidewalk that resulted in a plaintiff trip and fall lawsuit.  Based on the photographs and tree species, White mulberry (Morus alba), I was fairly certain her client’s tree was responsible for the sidewalk damage.

The attorney retained me and requested a site inspection and tree root assessment.  I trenched adjacent to the sidewalk and within a short time, encountered a three-inch diameter root growing under the sidewalk.  Further excavation revealed a network of two to four-inch diameter roots that had grown under the sidewalk, resulting in the tree roots lifting up the sidewalk panel, creating a hazardous condition resulting in a trip and fall accident.

I informed the attorney that tree roots lifting up the sidewalk, or root encroachment from her client’s tree resulted in the sidewalk damage, she said her civil engineer expert claimed it impossible for a tree root to lift a concrete sidewalk.  I questioned the engineers knowledge and experience with trees, was the civil engineer a certified arborist or horticulturist?

Although the answer was no, she felt his qualification as a civil engineer was superior to my qualifications as a certified arborist, tree risk assessor qualified, registered consulting arborist and a college educated horticulturist.  Her dilemma was having two experts who disagreed and she requested I alter my opinion.

I told the attorney altering my opinion to suit her needs was unethical, and I removed myself from the case.

What Causes Tree Roots To Lift up a Sidewalk?

The common myth is trees have tap roots that grow straight down into the soil.  While this may occur in very deep, loam soils, the reality is most containerized nursery grown trees lose their tap root in the container.  Once planted in our poor Southern California soils, when the tap root encounters physical soil obstructions, such as rock, clay or hardpan, the tap root divides and grows multiple roots around the obstacle, forming a fibrous root system.  Tap root grows into fibrous root system.

Trees require a spreading root system to maintain structural stability.  Trees dissipate energy generated during a storm or wind event by transmitting leaf, limb and trunk movement down to the roots.  A spreading root system anchors the tree movement and dissipates the energy far more effectively than a single tap root system.

Most tree roots grow within the top 24-inches of the soil horizon. Roots in top 24″ of soil.  Over time, structural tree roots (2-inch diameter and greater) growing within a shallow soil adjacent to sidewalks, footings, foundations, walls or othersub-surface infrastructure may cause damage.

Just as a twig grows into a branch, and then a limb, roots increase in length and circumference.  Irrigation water, sewer or water service leaks increase subsoil moisture beneath sidewalks or garage slabs, creating a perfect environment for root growth.

Cracked garage slab

As the root circumference increased, it exerts pressure on the concrete slab or footing above the root.  Depending on the species, root diameter might increase 1/8-1/4” annually.

Within five to eight years, a small feeder root may grow to one-inch in diameter or greater.

Ficus root cracked the garage slab

The root growth may be compared to the action of a hydraulic jack, as the circumference increases, the upward pressure on the sidewalk or slab may crack and or eventually cause tree roots to lift the sidewalk.  Concrete lifting may often occur at an expansion joint between concrete panels

Sidewalk lifted at expansion joint

Root network beneath sidewalk.

Roots seek out soil moisture, they can and will grow under walls, footings and garage slabs.  Roots are opportunistic, leaky plumbing, old cast iron sewer lateral or water services contribute to the soil moisture needed for roots to flourish. 

Sewer lateral root damage

Roots may infiltrate pvc, abs and cast-iron pipe through even the smallest of cracks or holes. 

Once inside, the roots expand in size and quantity, eventually completely clogging the utility.

If the tree crown has grown over a sidewalk or adjacent structure, it is a reasonable assumption structural roots (two-inch diameter and greater) have grown under the sidewalk, slab or footing.

Root growing under house footing

Planter areas confined by concrete pose one of the greatest risks for root damage.  City sidewalks often incorporate small, square planters within the sidewalk easement.

Roots lifting water meter and sidewalks

Confined planters quickly fill with structural roots, as well as damaging girdling root.  As the tree crown grows, so to do water absorbing feeder roots.  Over time, root mass and size increases, structural roots may begin to grow beneath concrete improvement while seeking out moisture.

Leaking water meter, high soil moisture, confined growing space.

The tree pictured above and to the right had a leaky water meter adjacent to the small sidewalk planter.  The leaky service provided idea soil moisture conditions for the roots to lift the water meter box, adjacent sidewalks and crack the curb and gutter.

Preventative measures to minimize root encroachment include a variety of root barrier methods.  All root barrier systems work best when the tree is installed.  Once roots have enlarged and matured, barrier mitigation is not successful.

In summary, our Southern California poor, shallow soils do not support deep tree tap root systems.  Most trees grow fibrous spreading root systems.  Structural roots emanating from the root collar extend to the edge of the tree crown, (drip line).  Most structural roots growing beneath sidewalks range from two to four inches in diameter, lifting sidewalk panels on average one-two inches. Trees growing in confined planters or adjacent to concrete, utilities or foundations may develop structural roots capable of lifting, cracking or damaging adjacent improvements.

Dealing with legal issues due to tree roots lifting up a sidewalk?

Attorneys should select an expert based on the case criteria, not simply a title, license or certificate. Choose an expert most appropriate to address the cause of the problem and develop opinions based on sound, industry practices.

Finally, A Turf Block Driveway With Thriving Turf!

Rarely have I seen a successful turf block driveway.  Turf block, turf stone, turf pavers are systems installed as living turf driveway alternatives.  The material provides structural support via plastic or concrete cells that are filled with a soil media for turf installation.  The block is designed to support vehicular traffic on driveways while providing a green alternative to concrete or asphalt driveways.

Turf blocks have been used for decades, but rarely have I seen thriving  turf grass within the block.  Not because of the product, but usually due to turf establishment and failure issues.  Due to reduced soil root area, soil compaction, irrigation infiltration and damaged soil structure result in poor turf establishment.  Soil preparation, drainage and proper irrigation coverage and operation are required to grow turf inside of a turf block system.

Lastly, using vigorous, warm season turf grasses that spread by horizontal solons, rhizomes, and rooting improves the successful establishment of turf grass, such as the Tiff hybrid Bermuda grasses developed for sports fields. Cool season turfs including rye, bluegrass and turf type fescues are clumping turfs that do not spread horizontally, thereby limiting establishment and healthy growth.  Cool season grasses are more susceptible to leaf and soil borne diseases, are easily stressed during hot summer months, nor are they tolerant of vehicular and pedestrian traffic and compaction conditions.  

Tiff hybrid Bermuda is well established within the turf block

A Horticulturists Local Neighborhood Walk

I took my usual walk through local neighborhoods surrounding Balboa Park in San Diego.  A glorious spring day, I couldn’t help but marvel at the beautiful ornamental landscape trees, shrubs and vines in bloom everywhere!  Very uplifting, glad plants are not affected by the virus!

Old Growth Redwood Destruction Continues

I read an L.A. Times article discussing ongoing logging of redwoods in Humboldt County.  In a battle spanning several generations, tree sitters and eco-activists are putting their bodies on limbs in redwood tree tops to prevent logging.

This is not the first time tree activists have climbed hundreds of feet up old growth redwoods to prevent logging the tree and surrounding trees.  It reminded me of a remarkable novel I read called “The Overstory” by Richard Powers.  The novel is about people and their interaction with and the affect specific trees and forests.

It primarily focuses on loss of old growth redwoods and firs in the pacific northwest and activists actions to prevent tree and habitat loss.  However, the novel was historical, taking place several decades ago.  Yet it appears old growth logging in Humboldt county continues to in present.

I recently visited, camped and explored the Jedediah Smith State and National Redwood park, not far from where present day logging takes place.  For me, the thought of logging off trees that are hundreds to over a thousand year old is difficult to accept.

We have commercial redwood farms for harvesting lumber.  Of course, it does not possess the grain, size, color and characteristics of true old growth redwood trees.  If we want future generations to be able to view and experience the incredible creation of a true, old growth tree, we MUST stop logging and preserve this resource.

The Benefits of the ANSI A300 Tree Care Standards for Tree Related Lawsuits

Guy + Chainsaw – Tree = Potential Lawsuit vs
ANSI A300 Tree Care Performance Standards

Does he know what he is doing?

Does he know what he is doing?

Background

Tree care professionals contracting for services are frequently members of the Tree Care Industry Association, (TCIA). The International Society of Arboriculture, (ISA), administers various types of arborist certification programs, including certified arborist or certified tree worker climber. The American Society of Consulting Arborist  offers arborists training and testing to become a registered consulting arborist, (RCA). These associations provide industry standards and best management practices for members to adopt into in their own practice.

Note the personal protective clothing, ropes, saddle etc.

Personal protective clothing, ropes, saddle etc.

In California, C-27 landscape contractors and D-49 tree service contractors are licensed by the state, both can legally perform tree care service. Prior to 1991, various industry associations, contractors and practitioners followed their own standards for tree care.

The industry recognized the need for a standardized, scientific approach and agreed to develop an official American National Standard, resulting in the American National Standards Institute (ANSI) A300 Tree Shrub, and Other Woody Plant Management Operations – Standard Practices.

They are voluntary industry consensus standards developed by TCIA and written by the Accredited Standards Committee (ASC) A300, whose mission is to develop consensus performance standards based on current research and sound practices for writing specifications to manage trees, shrubs, and other woody plants.

The ISA and ASCA are members of the ASC and their member practices should conform to the ANSI A300 tree care performance standards. The standards “apply to professionals who provide for, or supervise the management of trees, shrubs, and other woodsy landscape plants. Intended users include businesses, government agencies, property owners, property managers and utilities.” Many municipalities have adopted the ANSI A300 performance standards as part of their tree and landscape maintenance ordinance. The A300 standards are separated into 10 parts based on the tree care practice.

ANSI A300 Performance Standards for Legal Conflict Support

Arboriculture professionals adhere to the ANSI A300 performance standards for developing specifications for tree care. Gardeners, landscapers, designers, and handy men are not certified arborists and rarely have knowledge of industry standards. Even licensed landscape architects, civil engineers, general and landscape contractors may not be familiar with or have knowledge of the A300 standards. Ignorance of the standards is not a legal excuse for violating or ingnoring the standards.

The standards are separated into ten different parts. Through case experience, I have found three of the ANSI A300 standards applicable for plaintiff or defendant tree related legal actions. In conflicts I’ve been involved with, the civil engineer, landscape architects, general contractor, landscape and sub-contractors and even licensed tree care companies were not aware of the A300 standards. In some instances, industry professionals were aware of the standards but failed to adhere to the them.

Without proper planning and management, construction and development projects adjacent to existing trees commonly damage tree roots, trunks and limbs, increasing the risk of a potential tree failure and resultant lawsuit. ANSI A300 (Part 5) Standard Practices (Management of Trees and Shrubs During Site Planning, Site Development, and Construction) is the recognized industry standard for managing trees during construction and is the focus of this discussion.

The A300 Part 5 Performance Standard is intended for use for industry professionals, including all levels of government agencies, private entities including commercial, industrial and residential property owners and managers, engineers, architects and utilities for developing written specifications. The standards apply to any person or entity engaged in the management of trees, shrubs or other woody plants.

ANSI A300 Part 5 standard

ANSI A300 Part 5 standard

Without specifications for tree protection during construction and development, tree injuries occur. Depending on the severity of the injury, the defect may degrade the structural integrity of the tree. Over time, the injury may continue to decay, increasing the risk of failure and resultant damage to people and or property. The reason for the standard is to assess the level of risk and to provide information for risk mitigation.

Civil engineers, landscape architects and other professionals responsible for developing plans and specifications should be aware of the A300 standards. These professionals may not have the tree knowledge expertise, which is why the standard refers professionals to use a certified arborist qualified in tree management during site planning, development and construction.

The standard discusses implementation procedures that should be designed by a professional arborist including:
• Tree management plans in compliance with applicable ordinances and standards.
• Decision making should be based on the knowledge of health and safety of the tree resources present.
• Prime consultant and contractor should involve the arborist in the initial planning phases.
• Arborist site monitoring during construction should be specified to ensure compliance with plan requirement.
• Monitoring specifications should address demolition, grading, vertical construction, walks and pathways, playgrounds, excavations, trenching, drainage systems, and landscape.

For safety, the standard requires only arborists familiar with the standards, practices and hazards of arboriculture shall perform tree management. One of the objectives of the standard it to avoid damaging trees during construction; including damage caused by physical contact, grade changes and soil compaction. To achieve the defined objectives on any project, the arborist should be involved in the management of trees during all five phases of development including:
• Planning
• Design
• Pre-construction
• Construction
• Post-construction

Development and construction projects are complex, requiring planning and coordination among project shareholders. The prime consultant and or contractor should maintain arborist involvement throughout the various phases of the project in conjunction with the arborist developing specifications, resource assessment, conservation plans, monitoring and recommendations. The TCIA website has an exhibit of a Tree management plan flow chart defining what should occur during the development phases, arborist responsibility and development activity.

How the A300 Standard Applies in a Legal Context

The standard applies to all design and planning professionals such as civil engineers and landscape architects. These firms usually work as prime consultants and are responsible for producing the plans and specifications for development projects. They are responsible for knowing and adhering to the A300 performance standards. The same applies to prime contractors and their sub-contractors, and other project stakeholders.

Failing adherence to the A300 standards renders prime consultant(s), general and sub-consultants potentially liable if a tree related accident occurs. I used the A300 standard in a case involving a tree limb that fell from a tree onto an adjacent tot-lot.

A city decided to build a park within a former old growth forest. A civil engineer and landscape architect developed plans and specifications, including a grading plan with notes and a detail for tree protection. The general contractor, grading, and recreation equipment sub-contractors constructed the park. The design included a tot-lot with children play equipment built where trees were removed, with old, construction damaged trees remaining left intact at the edge of the tot-lot.

A few days after the park opened, a tree limb dropped onto the tot-lot, striking and killing a young child seated on a piece of play equipment. The parents sued the city, the design consultants and all the contractors because the defendants did not observe the city tree ordinance. The city ordinance adopted the A300 tree care standards as part of their tree ordinance, which the defendants ignored, arguing the standard did not apply to their trade(s). After extensive deposition testimony, using the standards in support of the Plaintiffs (parents of the deceased child), all the defendants settled rather than proceeding with a trial.

In another case, a property owner agreed to allow a guy to prune a tree. The guy claimed to have forestry experience. He had a rope tied around a limb that he cut just as a neighbor walked out of their house. The limb dropped, rebounded at the end of the rope causing it to swing and strike the neighbor in the face. In the resulting lawsuit, the A300 standards were used to support the plaintiff complaint with a resultant settlement from the insurer.

The A300 standards apply to tree care companies, certified and consulting arborists. Different standards may apply depending on the case. For example, A300 (Part 9), Tree Risk Assessment A. Tree Failure, provides performance standards for tree risk assessment and guidelines for establishing written specification and best management practices, (BMP).

As a certified and registered consulting arborist, tree risk assessment inspections and reports are consulting services I provide, I’ve incorporated this and other standards into my practice.  Tree care contractors might find other standards, such A300 (Part 1) Pruning, Part 5 (previously discussed) and Part 9 particularly applicable to their business.

In conclusion, the ANSI A300 Tree, Shrub, and Other Woody Plant Management Performance Standards are a powerful tool that may benefit a plaintiff or defendant involved in a tree related accident. The standards are broad reaching in scope and application to a wide variety of construction and development professionals. Attorneys and insures should consider the potential application of A300 performance standards in tree related cases.

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.