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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 plication Nun iber(s) Approva I Body: Director / S1 aff Approva I Date (gMs N 20' E 20' i� Signature 1 Catht n0 S 20' W 20' 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 T W Tree Status Alive Common Name Coast live oak 2022 DBH 33 OAIA IABLt I N1X1:h1VIEW SERVICE REQUEST REPORT SHARE Communty Development Department Plan ing Division — Cupertino CUPERTINO r APPRDUED Case # Approva I Body: Director / Staff A In t 9.,2 pprova a e Signature c T Freers applied T x lqwv a,Y