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Approved Documents - Arborist Report■�e Com- Div' ' - - opment Department Pla Cupertino CUPERTIN}}O TREEARj Case # �yD1 v1Expe,,endT Rd �g'1�1) �g,k Application Number(s) Approva I BodV i rec9tdrr u/i a fY18/19) Approva I Date 09/27/19 Signature Ms.MRhsR&QWhnan Director, Praiprat)pMoaagement Hunter Properties, Inc. 10121 Miller Avenue, Suite 200 Cupertino, CA 95014 Phone: (408) 255-4100 Email: melissa@hunterproperties.com Re: Arborist Report- Monterey Pines- 10121 Miller Avenue, Cupertino Dear Ms. Cullinan: At your request, I visited the above -referenced property on July 25, 2019. The reason for the consultation was to evaluate the health and condition of two (2) mature Monterey Pine (Pinus radiata) trees. The goal of the evaluation is to determine the recommended course of action to best ensure the safety of people (residents and tenants) as well as their homes and personal property/vehicles. During my inspection I made no attempt to climb the trees nor excavate any soil. This report, and the referenced attachments, serves as a summary of my evaluation. The two Monterey Pines are amongst a larger population of trees located on the property. Pine #1 has a 33" diameter at breast height (DBH) and a crown height and crown spread of approximately 80' and 50', respectively. Pine #1 is located against the fence line in the southwest corner of the property (see Attachment 1: Site Map). Pine #2 has a 27" DBH and a crown height and crown spread of approximately 60' and 40" respectively. Pine #2 is located against the fence line approximately 20 feet north of Pine #1 (see Attachment 1: Tree Location Map). Both Pine trees are adjacent to and extend over high voltage power lines, residential properties and subject property parking lot. The high voltage power lines run north to south along the west perimeter property line and adjacent to/under both Pine trees. A second set of high voltage power lines run east to west along the south perimeter property line and adjacent to/under Pine #1 (see Attachment 2: Pine Tree Pictures). The limbs on the lower half of each tree have been removed. The tree was likely "skirted" to maintain the crown at a height higher than the high voltage power lines. When the lower limbs exist the wind goes through the tree and around the tree. When the lower crown is removed it allows the wind to get under the raised crown of the tree creating an upward pressure that increases the potential for structural failure. A predominant amount of limbs that remain on each tree have been "lions tailed." Lions tailing is a particularly destructive pruning practice where an excessive amount of the interior branches are removed leaving only growth toward the tips of the limbs. Lions tailing negatively affects the health and structural integrity of the trees. Removing excessive amounts of needles reduces the trees' ability to Tree Tech Inc. 1 3633 Woodley Drive, San Jose, CA 95148 1 (408) 568-5408 1 alex@tree-tech.net generate food to help support and grow its root system. In addition, exposing previously shaded bark to full sun increases the risk of sun scald and splitting which weakens the limb and increases the risk of limb CoM Mp.ity Development Department Planning Division — Cupertino tUPERTINO Historically, Idc_��il. gees have reportedly experienced limb failure. Both Pine trees were recently pruned in MRRa��rrcnnh 2Q01 to help address the trees' structural deficiencies. In the subsequent 3 months Case # Pina W h�k�f�� P62" m, additional I0rr,b failures. Both limbs fell into neighboring residential yards causingWPJ:R�WMW One neighbor has recently communicated their safety concerns with the Approval BBr e ecpoer.7gg X escribed the property damage they incurred as a result of the limb failures and asd fo����s to removed (see Attachment 3: Neighboring Resident Property Damage). Approva I Date Signature TheR ke Reesdae currently being attacked by Red Turpentine Beetles (Dendroctonus valens). This is evidenced byratlaMaoigerpink-white pitch tubes on the lower trunks (see Attachment 2: Pine Tree Pictures) as well as accumulations of reddish -brown sawdust at the bases of the trunks. Beetles frequently attack stressed trees weakened by drought, disease, injuries or malpruning. Stressed Monterey Pine trees give off a chemical odor that attracts the Red Turpentine Beetle. The attacking beetles will release a pheromone attracting other Red Turpentine Beetles to the tree. The attack is usually more than a tree can overcome, especially for a tree that is already stressed. Except for general cultural practices that improve tree vigor, little can be done to control the Red Turpentine Beetle once a tree has been attacked. Because beetles live in the protected area beneath the bark, it is difficult to control them with insecticidal treatments. Treatments can be effective when applied consistently in a preventative manner prior to initial beetle attack. However, when the treatments are applied in a retroactive manner after the beetles have aggregated and penetrated the bark, it is generally found to slow, but not deter, its destructive progress. Beetle infested trees should be removed as they serve as a host to a population of beetles that will emerge and attack other nearby host trees. Pursuant to the evaluation detailed above, the Pine trees pose a significant hazard. The potential targets should additional limbs, or the tree itself, fail include high voltage power lines, neighboring residents, subject property employees as well as neighboring homes and personal property/vehicles. The recommendation is to remove the Monterey Pine trees and replace them with a species with a better - suited for the location and property. Native California Coast Redwoods (Sequoia Sempervirens) would be a recommended replacement species better -suited for the location and the property. The Property Owner desires shade for its parking lot as well as a privacy screen along the west perimeter property line. Coast Redwoods currently exist along the west perimeter property line for these purposes. The addition of two 36" box Coast Redwoods would complement the plant palette for this location as well as the property as a whole (see Attachment 1: Site Plan). Please feel free to contact me should you have questions or need clarification. Respectfully submitted, David �r 041.e2 David Gardner ISA Certified Arborist WE-7853A Attachments (3) Tree Tech Inc. 1 3633 Woodley Drive, San Jose, CA 95148 1 (408) 568-5408 1 alex@tree-tech.net ■o� DevelopmerltbDe&eporf Attachments- Hunter Properties- 10121 Miller Avenue Planning Division — Perimeter- rear Cupertino Pine Tree Pictures Pine p2- poor structure: crown skirted, lions tailed pruned, significant amount of stub cuts c� Attachment 2 . Wkw- a 6 Ave lift , . �14 IF 4 I