Why are Humans Blind to Understanding Trees?

Posted on August 3, 2023 by landscapeexpert

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.

Saving the Giant Sequoia Forest

Posted on June 13, 2023 by landscapeexpert

For several years, climate change and drought created conditions for uncontrolled California wildfires. These wildfires burned with such intensity, several Giant Sequoia, (Sequoiadendron giganteum), forests were heavily damaged. We have lost approximately 20% of the entire species, over 10,000 Giant Sequoias have been destroyed the past three years alone.

Although these magnificent trees are fire adapted, with an incredibly thick outer bark protecting the cambium within, the recent fires burned with such incredible intensity scores of trees were incinerated. Another fire adaptation are the Sequoia cones that normally open after a fire, distributing thousands of seeds that germinate and replenish the burned groves. Yet the fires were so hot, even the cones were destroyed, so the trees produced no new seedlings.

All of the groves are located in a relatively small band on the western slope of the southern Sierra range. Due to climate change, the southern Sierra range has become a dryer environment, very different than 2,000 years ago when these magnificent trees first germinated. As the forest regenerates, shrubs, fir, and cedar have replaced the Sequoias.

Sequoia seedlings require a lot of water to germinate and grow into juvenile trees. The hotter, drier climate and competition with other less favorable species, reduces Sequoia germination and ultimately, the survival of the species. Imagine Sequoia National Park without any Sequoia trees. Your kids and grandchildren might end up never being able to visit and enjoy these incredible trees. My father took me to the park when I was a child. My love for this species influenced my decision to study horticulture, eventually making my profession, first as a landscape contractor, later as a consultant and expert witness as certified and registered consulting arborist.

Fortunately, the Save the Redwoods League has teamed with the US Forest Service and National Park Service undertaking replanting thousands of redwood seedlings throughout several burned forest areas. The goal is to reestablish groves that can be managed to become fire resistant again. It is a massive undertaking, that has never been tried before. While the odds of any seedling becoming a massive, thousand year old monarch are depressingly low, (one in 10 billion), it is the morally right undertaking for mankind. Without restoration, the redwood groves will convert to shrub lands, a sad ending for the official state tree of California.

Read about the restoration efforts in this article from the Los Angeles Times.https://landscapeexpertwitness.com/wp-content/uploads/2023/06/Los-Angeles-Times-eNewspaper.pdf

Bromeliads in the Landscape

Posted on January 14, 2023 by landscapeexpert

With spring time on the horizon, it was time to start sprucing up my landscape garden. I try to make the garden interesting using a variety of plant materials with differing form, texture and foliage color. My latest planting incorporates bromeliads into the landscape. There are countless species to select from, their form, leaf color, texture and flowering are extremely unique and incredibly beautiful. Fortunately, there is a fantastic nursery in north San Diego County specializing in bromeliads and tillandsia, www.birdrocktropicals.com

Visits are by reservation only, but well worth it. Although I’m a horticulturist, bromeliads are a specialty species I had little actual knowledge on species planting and maintenance requirements. I have a very difficult planter area that is full shade in the winter, full sun in the summer. Another planter changes varies from shade to part shade seasonally.

I received a great education while guided through the nursery, learned a great deal about bromeliad breeding, potting and maintenance. Another great tip they provided was leaving the plant in the container while planting in the landscape. Bromeliads, similar to orchids, are tropical understory plants. They are adapted to very poor, thin tropical soils and do not like heavy, clay poorly drained soils. Unlike typical ornamentals. they also prefer contained environments, smaller plants do not like being potted into large containers. They should remain in smaller containers until they grow multiple pups, filling the container to the point where watering becomes difficult.

Another advantage of planting them in their containers is being able to remove them if the environment becomes to shady or sunny for the individual plant. I’m excited about these beautiful plants, hoping they grow and multiply!

Top 10 List: What we have learned about trees

Posted on July 28, 2021 by landscapeexpert

While reading the Western Arborist, an tree industry publication, I came across a top ten list of what we have learned about trees by Nelda Matheny and Jim Clark, both very well known researchers, teachers, lecturers and industry titans. I have had the honor to meet both, read their work and attend their workshops. So when I came across their top ten list, I felt compelled to share it with you.

10. Our view of trees has evolved from being niceties to being necessities.
9. Tree preservation requires space.
8. Tree care practices can have either positive or negative consequences.
7. Soil health is vital to tree health and requires protection and nurturing .
6. Structural defects in mature trees can largely be prevented through selection and early care.
5. Trees are both biological organisms and mechanical structures.
4. Tree care applies general information to specific genotypes.
3. Tree risk assessment is an imprecise endeavor.
2. We must use science to guide tree management.
1. Education is a lifelong process.

Bonus: It’s not enough to know about trees.
We have to know things that affect trees and things trees affect.
We have to describe and present our work.
CERTAINTIES
1. Trees will continue to grow and require care.
2. Trees will become more important to people and cities.
3. If you stop learning the world will pass you by.
Nelda Matheny & Jim Clark, Western Arborist, Fall 2020

As a certified arborist, tree risk assessor qualified, registered consulting arborist, C-27 landscape contractor and professional horticulturist, I have spent my personal and professional life involved with trees. They are my passion and profession, I’m extremely grateful for spending a lifetime with trees. For me, trees provide beauty, aesthetics and functional benefits. But most important, trees provide me an emotional connection to our planet. We could exist without trees. They bring me happiness and beauty, they uplift me and provide calm and peacefulness in times of need. They are truly magnificent biologic organisms we should maintain, share, and protect for future generations.

Tree Roots Lifting up Sidewalk?

Posted on August 11, 2020 by landscapeexpert

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!

Posted on June 23, 2020 by landscapeexpert

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

Trip, Slip and Fall Hazard: Hidden Depressions in Grade

Posted on May 19, 2020 by landscapeexpert

Successful landscapes require:

Proper grading, drainage and amended soil.
An automatic irrigation system achieving 100% head to head coverage.
Properly installed, high quality plant material.

Each of these functions may require a specific type component, installed at a specific height or location to reduce the potential of creating a site hazard that may result in an accident. In commercial applications, landscape plans usually include details and specifications dictating type of product and how it should be installed.

Many common landscape products may be improperly installed including:

Pop up heads may be incorrectly set to grade against a sidewalk.
Valve or drainage boxes set too high or low relative to finish grade.
Shrub head installed on a riser adjacent to concrete improvement.
Hidden, obscured depressions in grade due to substandard compaction, settlement and subsidence.
Drainage box set too low.

Improper product selection or substandard installation practices may appear obvious. A pop up sprinkler head set above the top of adjacent concrete sidewalk creates a trip hazard. A drainage structure set well below the turf grade creates a trip slip and fall hazard. Selecting and installing a spray head on a rigid riser next to a pedestrian sidewalk is a sub-standard industry practice that creates a trip and fall hazard.

Spray head on a riser next to a sidewalk creates a trip hazard.

Not all landscape hazards are visible. Turf areas may have grade depressions or holes that are hidden by overgrown turf grass. Depending on the cause and time period, turf grass may completely hide the depth, location and size of the depression or hole, creating a hidden hazard.

A depression, rut or hole may result from several factors. Repeated mowing on saturated turf may create ruts. Overwatering may cause irrigation or utility trench settlement. A dead tree removed from a turf area may result in a future depression if the grade is not properly backfilled and compacted.

A seven inch deep hole hidden by turf grass.

Bermuda grass is a fast horizontal spreading turf-grass used in parks and recreation facilities throughout the country. Unless regularly aerated and de-thatched, Bermuda grass in known to grow a thick layer of thatch. Over time, the thatch layer can increase the turf grade several inches above adjacent sidewalk and curbs.

The backfill in utility trenches installed across pre-existing turf may settle, creating a depression in the sub-grade. The photo depicts the edge of a trench cut across an asphalt driveway, across a turf area. The trench backfill eventually settled, creating a trench sub-grade depression hidden by the Bermuda grass.

Thatch, hidden depression and sanded turf.

The depression resulted in a trip and fall accident. After the accident, several hidden turf depressions were “sanded” to fill depressions to proper grade.

Not all landscape hazards are open and obvious. Even a perfectly installed landscape may develop hazardous conditions if not regularly inspected and maintained.

Irrigation systems should be monitored, inspected, tested and adjusted monthly. Turf should be trimmed around utility boxes and vaults regularly, aerated and de-thatched annually to maintain optimum performance and minimize grade changes. Drainage structures should be grade adjusted, repaired or replaced when damaged. Valve, electrical and junction boxes should be monitored for grade changes and adjusted as required. Bark mulch thickness should be monitored and supplemented annually to maintain proper coverage and grade.

In summary, a properly installed landscape is composed of several systems and components that require regular ongoing maintenance for optimum performance, efficiency and safety. Pro-active landscape maintenance may reduce potential hazards, resultant accidents and lawsuits. These actions demonstrates an Owner’s recognition of protecting the health and safety of the public, pedestrians, friends and family who may visit and use the site and may prove useful in a legal action.

A Horticulturists Local Neighborhood Walk

Posted on May 13, 2020 by landscapeexpert

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!

Online Site Inspections with Corona Virus: A New Paradigm?

Posted on April 24, 2020 by landscapeexpert

The corona virus and resulting stay at home order has prevented me from scheduling or attending site inspections. I require site inspection for most forms of consulting work, including as a consulting arborist or expert witness.

Tree failures, health and risk assessment
Tree inventories
Tree and nursery appraisals
Tree roots and infrastructure damage.
Landscape appurtenances creating trip and fall hazard.
Obscured landscape hazards, grade changes
Irrigation operation, maintenance issues

A client wanted me to attend and observe asphalt paving taking place adjacent to an 80 year old Torrey Pine. I had previously consulted on preserving this tree during construction on an adjacent property. The client was repaving his driveway on the alley, the pine is right on the edge of the paving.

Due to California stay at home orders, I informed the client I could not be present to observe the paving to make recommendations, so we used the Facetime app and did an online site observation whereby I watched in real time as the work was being performed. I was able to give the client recommendations in real time.

Moistened towel protect surface roots

He was concerned about root damage, and rightly so. Some of large buttress roots would be impacted by the paving. Instead of cutting, I recommended covering the roots with wet towels, fabric etc, then placing moistened sand base, then pave over the roots.

Moistened sand placed over protected roots

As terrible as it is, the corona virus has created many new ways for industries to re-invent how they do their business. This was the first time I have attempted on online site inspection and it worked! This may not be applicable for the types of investigations I perform, but there is a great new tool I can use for certain types of investigations during stay at home and even beyond.

Asphalt paving over protected roots

The financial savings for the client are obvious. Travel costs for me to travel to Los Angeles, Orange or Inland Empire typically range from $500 to $1000 or more if hotel stay is required.

Not all inspections can be performed remotely. Forensic investigations that require measurements, excavations, sampling, testing etc may not be applicable.

Since this is new to me, it will take some real time client cases for me to determine how and when I can utilize this new tool.

Joshua Tree Extinction by End of Century?

Posted on April 14, 2020 by landscapeexpert

I just read an article in the Los Angeles Times about a potential listing of the Joshua tree as an endangered species. The western Joshua tree, Yucca brevifolia, is one of two genetically distinct species that occur in California. It range extends from Joshua Tree national park westward along the northern slope of the San Bernardino and San Gabriel mountains, northward along the eastern flank of the Sierra Nevada and eastward to Death Valley.

Approximately 40% of the western tree range is on private land, the eastern range is centered in the Mojave National Preserve and eastward into Nevada.

After decades of climate change, development, drought and wildfires, the species is facing a rapidly increased the risk of extinction. State Department of Fish and Wildlife Commission will decide in June whether to accept the department’s recommendation to declare the tree an endangered.

As usual, there are two sides to the issue. Conservationists see this as a triumph of state environmental law while critics claim it as a misguided overreach because Joshua trees are already protected under many city and county ordinances and within the 800,000 acre national park.

Environmentalists argue existing state and local ordinances are largely inadequate at protecting species habitat loss, the endangered species listing will finally provide a statewide protection for the species, including requiring wildlife managers devise a recovery plant for the species, which could limit development in SoCal real estate.

The Joshua tree exists in high desert communities such as Yucca Valley or Hesperia, communities with lower average median household incomes. They are concerned the listing would impose additional burdens to real estate development, making it tougher to improve their property or curtail new development in their communities.

However, researchers warn time is running out. The tree’s range is contracting at lower elevations, its reproduction has come to a halt. Trees are failing to reproduce at lower, hotter elevations. They could become extinct in California by the end of the century!

This would be a terrible outcome for a truly incredible species. This remarkable species deserves protection. I believe this tree, in its own way is as majestic in its high desert setting as the coast redwood. These are species distinct to our California heritage. The Joshua tree deserves protection for our future generations to enjoy, marvel and be uplifted by this unique species.

Download a pdf of the article here: Los Angeles Times – eNewspaper