TR-2023-012 - Arborist Report_1 Apple ParkwayCommunity Development Department WOOD
Planning Division — Cupertino ARCH IT CC T 41 R E
CUPERTINO APPROVED
Case # TR-2023-012
Application Number(s)
January 19th, 2023
Approval Body: Director / Staff
Approva I Date 04/03/23
Community Development Department 10300 Torre Avenue Cupertino, CA 95014
Signature Catherine Tarone
SUBJECT: ARRMST REPORT FOR PROPERTY AT: 1 Apple Parkway
This arborist report includes the observations and assessment of one (1) Quercus agrifolia tree
along Calabasas Creek on the SE side of the Apple Park Campus. The site was visited on
Wednesday, January 4, 2023.
Assignment: Review one (1) dead Quercus agrifolia tree at 1 Apple Parkway.
The assignment requires the following activities: visit the site, verify the tree, list the tree
species, diameter, crown radius, tree condition, impacts to the property, and mitigation options.
Observations: The tree tag number is 4421, and the tree's history is found in TreePlotter,
Apple's tree inventory program. The tools used were diameter tape, a screwdriver as a probe
and hammer. Crown height and radius were estimated. A diameter tape is used to measure the
trunk diameter at approximately 4.5 feet above grade. The tree was assessed and rated for
health and structure, and overall condition considering branch structure, decay, leaf quality,
vitality, dieback, lean, and other issues that affect the state of the tree.
The tree health condition rating was determined by observing the tree foliage, twig growth, leaf
density, and dead branches. The structure rating was determined by observing branch
attachment, crown structure, trunk flare, surface roots, decay, insects and diseases, growth
habit, and any physical damages. The overall condition combines the health and the structure
ratings based on the most significant conditions.
The rating system used for both health, structure, and overall condition is:
1. 0% dead;
2. 1-20% very poor/severe decline;
3. 21-40% poor/declining
4. 41-60% fair;
5. 61-80% good; and
6. 81-100% excellent.
The matrix below shows the data found during the site inspection.
Community Development Department
Planni
g Division
— Cupertino
CUPERTINO
Rating
AP.PR
Species
VELDk Diameter
Height
Crown
Radius
Case #
R-2023
Orloes
Feet
Feet
A
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Approva I Body:
Director
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Approva I Date
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Signature
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Case Manger
Condition I Comments
The tree is in
No severe decline
recovery with 95% of
possible the crown
dead.
Discussion: The property is 1 Apple Parkway, Cupertino, CA 95014. The Quercus agrifolia tree
assessed is located along the perimeter of Calabasas Creek. This Quercus agrifolia was
transplanted from on -site in early 2014. This was a very large Coast Live Oak transplant that was
growing on the site before redevelopment. The success vs. failure of transplanted trees depends
on the prep work before the transplant, the volume of roots retained in the root ball, and the
aftercare. With a tree of this size and age, all the above items must be perfect for long-term
success. Likely, the amount of root mass readily available to move was less than required for
long-term success.
The tree shows signs of stress, including thinning of the crown, change in foliage color, and
borer infestation along cracks in the bark on the trunk fairly soon after transplanting. This tree
started its decline in health in August 2015. The crown continued thinning over time.
Boring insects are attracted to wounded areas and trees under physiological stress. I did not
excavate the bark to look for larvae. However, based on the appearance of the exit holes and
the frass, the most likely insect is the Western Sycamore Borer (Synanthedon resplendens), a
common native insect found on Coast Live Oak. Eggs, laid in small cracks in the bark, hatch in
the summer and tunnel into the inner bark. The damage is considered to be of minor
importance to the overall health of the tree. The decline is more likely due to insufficient root
volume at the time of transplant.
A great effort to turn the tree around was made. The tree was placed on its own irrigation valve
to make it feasible to control irrigation frequency and volume. The irrigation application was
changed from a flood system to a drip system to improve water distribution. A soil moisture
sensor was installed to improve moisture monitoring. The tree was inspected weekly with a
visual inspection and soil probe to manually check soil moisture and compare it with the
reading of the soil moisture sensor. Regardless of the effort, the decline continued until it hit the
point of no return. This tree is dead for all practical purposes.
Conclusion: The Quercus agrifolia tree was determined to be in decline to such an extent that
its demise is imminent, with no opportunity for recovery or repair, with less than 5% of the
crown alive. Per the City of Cupertino's ordinance, CHAPTER 14.18: PROTECTED TREES, section
14.18.020 Definitions this is considered to be a "Dead Tree."
Community Development Department
NPAWqg:ffj� Rjc3n3fi!'dW&yjff6us agrifolia tree in the same general location to mitigate the
tUPERTINO loss of the r,$rff8F�%ercus agrifolia tree.
Case # R-2023-012
A plication Numbers)
Ty on Carroll
Approva I B�YLQB�TJWW.Lertifiecl Arborist
Approva I Date 04/03/23
Signature Catherine Tarone
Case Manager
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Tree
Status Alive
Common Name Coast live oak
2022 DBH 33
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SERVICE REQUEST REPORT SHARE
Communty Development Department
Plan ing Division — Cupertino
CUPERTINO r APPRDUED
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