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HomeMy WebLinkAboutAGENDA REPORT 2012 0606 CC REG ITEM 10N ITEM 10.N. City Councii Meeting ' - CIA MOORPARK CITY COUNCIL _ AGENDA REPORT TO: The Honorable City Council FROM: Allen M. Walter, Parks and Landscape Superintendent DATE: May 9, 2012 (CC Meeting of June 6, 2012) SUBJECT: Consider Approval of the High Street Pepper Tree Recommendation Plan for the Removal of Fourteen (14) California Pepper Trees with a High Risk of Structural Failure SUMMARY In December 2011, licensed arborist Kerry Norman provided the 2011 High Street Annual Pepper Tree Evaluation report to the City (see attachment 2). The Annual Report recommended the removal of twelve (12) high risk Pepper trees that contain advanced decay or large cavities and are at risk of structural failure, and one (1) dead from Armillaria root disease. Since the December report, two (2) additional younger Pepper trees succumbed to Armillaria root disease and died bringing the total to fourteen (14) Pepper trees. The High Street Pepper tree population, protected under the 2007 California Pepper Tree Maintenance Plan and the 2006 Environmental Impact Report, and the Ventura County Historical Landmark Number 72, provides procedures for the management of the Pepper trees. Therefore, the arborist recommendation was forwarded to the City Attorney to determine consistency with the Annual Arborist Report, the 2007 California Pepper Tree Maintenance Plan, the 2006 Environmental Impact Report (EIR), and related October 2004 Settlement Agreement. Council is being asked to consider and approve recommendations in the High Street 2011 Arborist Annual Report for the removal of eleven senescent Pepper trees and three dead Pepper trees over a period of three years beginning in July 2012. BACKGROUND In 2004 the City removed 5 diseased pepper trees. The City was subsequently challenged on this action as being inconsistent with the Historical designation of the 246 Honorable City Council June 6, 2012 Page 2 High Street Pepper Trees and an October 2004 Settlement Agreement resulted in the preparation of an EIR and the Pepper Tree Management Plan In 2007, licensed arborist Michael Mahoney prepared the High Street California Pepper Tree Management Plan. The Tree Management Plan approved by City Council as Resolution No. 2007-2584, currently provides procedures for the management of the High Street Pepper trees. The California Pepper Tree Maintenance Plan and Environmental Impact Report (EIR) guidelines (Resolution No. 2007-2584) were developed to maintain the Pepper tree population on High Street. The guidelines provided for an annual arborist Pepper tree evaluation report, Pepper tree maintenance (trimming, thinning, and replacement) and wildlife inspection to protect any wildlife or migratory bird nesting in the Pepper trees. Arborist Mahoney was contacted to perform the annual High Street Pepper tree evaluation in 2009. However, Mr. Mahoney relocated to Northern California and was unable to perform the evaluation. Mahoney recommended licensed arborist Kerry Norman, an arborist with specialized knowledge of California Pepper tree traits and the inherent risk involved in the aging (senescent) of Pepper trees, as his replacement. In 2009, Arborist Kerry Norman replaced Mahoney and in 2009, 2010, and 2011 reviewed and prepared the High Street Pepper Tree Annual Report. In the 2007 California Pepper Tree Maintenance Plan, Mr. Mahoney identified five (5) senescent Pepper trees with conditions of instability that cannot be mitigated and that these five trees should be removed at the earliest opportunity. However, before a removal plan could be developed, the trees were lost to decay compounded by environmental conditions (wind, rain, etc.) and replaced. In the 2009, 2010, and 2011 Annual High Street Pepper Tree Evaluation, additional senescent Pepper trees were identified with the same or similar instabilities that were identified in the five senescent Pepper trees listed in the 2007 California Pepper Tree Maintenance Plan for removal. In all reports the Pepper tree conditions could not be mitigated and removal was the only option. The arborist (Norman) strongly recommended that the senescent Pepper trees should be removed because they pose an imminent risk for structural failure that cannot be reasonably mitigated, therefore, the trees should be removed. In the 2011 Annual Arborist report, there were eleven (11) senescent high risk Pepper trees evaluated as having conditions of instability, which place the Pepper trees at risk for structural failure and should be removed immediately based on the size of the trees' cavities, advanced level of decay, condition of the wood in the decayed areas, and the presence of wood decay pathogens, all indicating a high probability of tree structural failure. 247 Honorable City Council June 6, 2012 Page 3 Staff reviewed the 2007 California Pepper Tree Maintenance Plan for High Street, the 2006 Environmental Impact Report, and the Ventura County Historical Landmark guidelines and procedures and found the eleven trees recommended for removal had the same conditions seen in the five trees listed in the 2007 High Street California Pepper Tree Management Plan for immediate removal. The 2011 High Street Annual Pepper Tree Evaluation report was sent to the City Attorney to determine if the 2007 California Pepper Tree Maintenance Plan and the 2006 Environmental Impact Report supported mitigation of future tree removals listed under 2007 High Street California Pepper Tree Management Plan for senescent trees allowed for immediate removal. The City Attorney's review found the mitigation measure and language in the plans supported the environmental impacts of future Pepper tree removals. After considering all the factors noted in the 2011 High Street Annual Pepper Tree Report, aggressive and timely pruning being implemented over the past three years is only temporary relief of the serious Pepper tree problems on High Street, and Pepper tree removal is now needed to mitigate high probability of structural failure. DISCUSSION Staff maintains the Pepper tree grove along High Street in a safe and aesthetically pleasing manner, consistent with standard tree care practices. High Street currently has 52 California Pepper trees of various ages and health conditions that are continually monitored for changes in structure and health. The High Street Pepper Tree Management from 2007 to 2011 is as follows: Tree Maintenance (Grid Trimming) All High Street California Pepper Trees Trimmed: March 12, 2007 All High Street California Pepper Trees Trimmed: October 1, 2007 All High Street California Pepper Trees Trimmed: June 20, 2008 All High Street California Pepper Trees Trimmed: November 14, 2008 All High Street California Pepper Trees Trimmed: August 20, 2009 All High Street California Pepper Trees Trimmed: August 27, 2010 All High Street California Pepper Trees Trimmed: January 31, 2011 Removals and Replacements 105 High Street-Removed / replaced October 2007 192 High Street-Removed / replaced October 2007 260 High Street-Removed / replaced October 2007 310 High Street-Removed / replaced November 2007 248 Honorable City Council June 6, 2012 Page 4 310 High Street-Removed / replaced October 2007 349 High Street-Removed / replaced January 2008 No Removals or Replacements in 2009 No Removals or Replacements in 2010 193 High Street — Removed / Replaced September 2011 220 High Street — Removed / Replaced February 2011 The eleven high risk trees detailed in the 2011 Annual Pepper Tree Evaluation Report are in decline and ongoing aggressive pruning and canopy reduction may reduce tree or limb failure, but it does not reduce or slow disease and pathogen activity inside the tree. In fact it reduces the tree's ability to defend against it. Therefore, the only solution is to remove the failing tree under regulations set forth in the 2007 California Pepper Tree Maintenance Plan, the 2006 Environmental Impact Report, and the Ventura County Historical Landmark Number 72 conditions. After determining the 2007 California Pepper Tree Maintenance Plan and the 2006 Environmental Impact Report supported the environmental impacts of future pepper tree removals, staff's proposed plan is to remove all eleven high risk and three dead Pepper trees (fourteen trees) on High Street, over three (3) one (1) year phases. The tree removals will be spaced out throughout High Street to avoid three (3) large open spaces with three (3) small replacement Pepper trees. Instead the replacement trees will blend in with the existing older Pepper trees. This will provide one (1) to three (3) years of growth before removal of an additional high risk tree within that same area. The proposed three (3) one (1) year tree removal plan is as follows: Phase I: FY 2012/13 Six (6) Pepper Trees 137 High Street, Tree Tag Number: 06 — Dead - Non-Historic (8"DBH) 137 High Street, Tree Tag Number: 07 — Dead - Non-Historic (11"DBH) 220 High Street, Tree Tag Number: 49 — Dead - Historic (51" DBH) 233 High Street, Tree Tag Number: 14 — Mature - Non Historic (25" DBH) 310 High Street, Tree Tag Number: 30 — Historic- (43"DBH) 293 High Street, Tree Tag Number: 33 — Mature - (35"DBH Phase II: FY 2013/14 Three (3) Trees 165 High Street, Tree Tag Number: 09 — Historic- (40"DBH) 294 High Street, Tree Tag Number: 32 — Mature - (26"DBH) 270 High Street, Tree Tag Number: 35 — Historic- (34"DBH) Phase III: FY 2014115 Five (5) Trees 192 High Street, Tree Tag Number: 46 — Historic - (41"DBH) 213 High Street, Tree Tag Number: 13 — Historic - (43"DBH) 230 High Street, Tree Tag Number: 36 — Historic- (59"DBH) 294 High Street, Tree Tag Number: 31 — Historic - (42"DBH) 249 Honorable City Council June 6, 2012 Page 5 165 High Street, Tree Tag Number: 08 — Historic— (38" DBH) See Attachment 1, street plan for Pepper tree removal locations on High Street. Once the Pepper tree has been removed and stump grinding is complete, a 24" box (Schinus molle) Pepper tree replacement will be planted per the High Street California Pepper Tree Maintenance Plan requirements. Acknowledging the community's regard for preserving the Historic High Street Pepper trees though not required by the October 2004 Settlement Agreement, staff contacted the involved party and they concurred with the City's planned action to remove the 11 diseased and 3 dead pepper trees. A second issue to be addressed is the diagnosed Armillaria Root Disease present throughout the Pepper trees population on High Street that has recently killed three (3) Pepper trees. The disease has no cure and is caused by fungi, which lives as parasites on living host tissue or as saprophytes on dead woody material. As parasites, the fungi cause mortality, wood decay, and growth reduction. It spreads primarily by new host root contact with infected roots or by airborne fungi spores, and may live in the soil from one (1) to two (2) years. The only effective removal of the fungi is the removal of all trees, fumigate soil, and expose the soil to sunlight for one (1) to two (2) years. That option is not available to the City to eradicate the fungi. Therefore, the only option is to manage and limit the disease buildup and reduce its impact. The recommended treatment where individual trees are of high value is to limit the disease buildup and reduce its impact through the use of chemical fumigants, such as chloropicrin, methyl bromide, and carbon disulfide to reduce the infection level. These fumigants are applied in and around the base of infected stems or in holes left after trees have been uprooted. However, the use of these "highly" toxic fumigates will not work in a residential and commercial area such as High Street. The only option available to manage and limit the disease buildup and reduce its impact on the protected High Street Pepper trees is by removing the three the (3) dead Pepper trees, remove as much of the contaminated soil and roots as possible (sidewalk constraints) apply systemic fungicide to open hole soil surface, leave the exposed holes to atmospheric conditions for fourteen (14) days, replant trees, and backfill with new fungi free soil with additional systemic fungicide added. Unfortunately the widespread fatal Armillaria Root Disease infecting most of the historic Pepper trees on High Street is not treatable; however, staff will continue to prolong life as long as possible to preserve these trees through constant monitoring and maintenance practices. 250 Honorable City Council June 6, 2012 Page 6 FISCAL IMPACT The removal and replanting of fourteen (14) High Street Pepper trees estimated cost is $9,524.00 paid over a three fiscal year period. High Street Pepper Tree removal and replanting cost estimates are as follows: Fiscal Year Removal Cost Replanting Cost Total FY 2011-2012 $2,376.00 $1,212.00 $3,588.00 FY 2012-2013 $1,350.00 $ 606.00 $1,956.00 FY 2013-2014 $2,970.00 $1,010.00 $3,980.00 Totals $6,696.00 $2,828.00 $9,524.00 The Citywide tree services maintenance budget fund 2300.7900.7900.9330 will be impacted $6,696 over three fiscal year periods to fund the Pepper tree removal as shown above. Boething Tree Lease will provide the fourteen, 24 inch box replacement Pepper trees under their lease agreement. West Coast Arborist will replant the 24 inch box replacement trees, per the 2007 High Street Pepper Tree Maintenance Plan, impacting the fiscal year budget over three years by $2,828. RECOMMENDATION: ROLL CALL VOTE Approve High Street Pepper tree removal plan of fourteen high risk senescent Pepper trees identified in the report over the next three years. Attachments: 1. High Street Pepper tree three year removal plan 2. 2011 High Street Annual Pepper Tree Evaluation Report 251 Moorpark Av. ATTACHMENT 1 (rear s tag#1 ;IrNf�. r tag 112 lag#52 ' lag#3 tag 1151 Y tag 114 lag 1150 Walnut St. tag 115 137 High St. •tag#6 t' Wo/r (market) tag#49 ' 44'o/c 5J•Oh lag#48 �, • lag 117 (vacant lot) 192 High St (professional building)45'n/c (old station) 11W, tag 1147 16•hg 118 zoo/ 165 High St. tag 1146 r, 5l Or t • lag#9 9#45 to F (storefront) � r . 500/r 1 p1r ( tag#10 (storefront) 38.o/. tag#44 •1,p'15I :I��. tag#11 (storefront) . tag#43 '�:/11} .1•Ml, tag 1112 tag#42 ; (restaurant) (slorrlront lag#41 �W., s tag#40 o, Bard St. r�•, lr= lag#13 44'o/c 213 High St. tag#38 c`}?IW 1. (vacant building) tag#37 r } 56'o/r tag#36 tag#14 233 Fligh St. (professional building) tag#15 tag#35 I I li'tag#16 57'0/ 255 Fligh St. (mulrhe(I tot) (storefront) tag#34 I f. < tag#17 273 High St. (residence) tag 1133 (fre station) tag#32 0 11 tag 1131 Magnolia SL tag#20 (restaurant) tag#30 (parking 101) r r_ 1 'Ir. tag #29 tag#21 (residence) tag 028 tag#27 ;vi1 1�U'Ic_lag#22 349 Fligh St. tag#26 i,..r<< ,t` (blacksmith s shop) Symbol Type of Tree` #-of Trees II 361 Fligh St. Young 10 lag#23 (vacant lot) Shade 23 tag#24 Veteran 11 415 High St. �} £ Senescent _- 5 -- I!. I tag 1125 (vacant lot L S A ZSI • PHASE I l [C;UIZI� 3.2 (5Mn1.1.1{ti SIZIO 511n1)1•:'I'I(KF (I.nit(:1.R517.t:.) PHASE II VETERAN (I.At(GF:lt SIZF.> PHASE III SI•:NI-SCEN'TTREI,: C;<rfifi)rrliu PepJ)cr'Gecs Nfainten(uu'('flan (LA ltcl:u sli.r:) Enuit-onmenfal Impact Repoo ti(IIIM 1•:('A1.11-ORNIAI'PI'I'h.R nti;l�SM:VNIPNAN('Itl'I.AN.III(i1151'I(lil•:'I•,b1Onitl'AItK.('A C)alil'ol•llia Pepper Tree IIIusU•ative Plan R:.All'Kit(1'.(i:Rgvntstlillt'gxpprr tree pl:ul.cdr(I J/27lIIbl 252 ATTACHMENT 2 December 29, 2011 Mr. Allen Walter City of Moorpark 799 Moorpark Avenue Moorpark, CA 93021 Regarding: High Street Pepper Trees Moorpark, CA Dear Mr. Walter, At your request I visited the above referenced site December 15,2010. The purpose of this visit was to perform a visual inspection of the California pepper trees (Schinus molle) along High Street. I was asked to assess their general health and structural condition,and identify trees that are considered to be at high risk of structural failure. Included are my report,tree photos and matrix spreadsheets summarizing tree conditions and recommendations. Summary and background A total of(50) pepper trees were inspected as part of this study. Overall the trees appear to be in healthy condition and most display good color and signs of average seasonal shoot growth. Keep in mind that tree health and structure are two completely different characteristics and that a tree displaying signs of good health and vigor may contain severe structural defects and also be at high risk for structural failure. With the exception of recent pruning,it appears that few if any recommendations from my previous report have been implemented; this mostly pertains to correction of soil grade and replacement of some of some of the younger more recently planted trees. Based on my visual inspection I have identified (12) trees that contain multiple defects such as advanced decay and or large cavities, and are considered to be at risk of structural failure; these include trees #8,9, 13, 14,30, 31,32, 33, 35,36,46 & 49. The twelve trees identified above are recommended for removal due to serious problems relating to trunk and limb stability and their high risk for structural failure. 253 High Street Pepper Trees December 29, 2011 Moorpark,CA Page 2 Trees #9, 13,30,31,32,33 & 36 identified for removal are also cited in the 2006 report prepared by Michael Mahony,as having major to extreme defects and problems with trunk,root and or scaffold limb stability. Defects in trees#8, 14, 35,46 &49 have progressively worsened over time and all 12 trees have reached the point where conditions of instability cannot be reasonably mitigated,much like those trees lost in the original Mahoney report section 12.1 "Senescent Trees Removals and Replacements". Overall very little change in condition was observed in the trees,structural defects do not appear to have significantly worsened and the trees are basically in the same condition as in my 2009 inspection. I have included a few photos to update the condition or additional findings in some trees. Tree#49 has considerably declined since my inspection in 2010, visually diagnostic signs of oak root fungus (Armillaria mellea) was observed in the cambium layer at the base of the trunk; the tree is all but dead and it is recommended that it be removed as soon as possible. Decay and cavities were identified in several other trees,however I believe these trees can remain in place with relatively low to moderate risks that can be mitigated by regular inspections,pruning and ongoing maintenance. Several of the small more recently planted pepper trees display signs of defective/girdled root systems. Signs include excess movement at the root crown when pushing on the trunk or trunk lean. These trees should be checked and replaced as needed,as they will certainly be problematic in the future if the roots are in fact girdled as I suspect. Many of these trees also appear to have excess soil atop their rootballs with the root collar buried. Soil grade must be checked and corrected as needed to the proper grade. Since my last inspection some of these trees anchorage seems to have improved but I remain skeptical about of their stability for the future. Limitations Visual tree inspection was performed from ground level. No extensive or invasion diagnostic procedures were implemented as part of this study. Lower portions of the trunks were sounded using a rubber mallet to help identify cavities and areas of decay, and a metal probe was used to measure depth and level of cavities and or decayed wood. There are no formulas or tests that determine with certainty whether or when a tree might fail. The practitioner must primarily rely on his or her education and experience when performing tree risk assessments. It is has been found that visual assessments based on professional experience (application of procedures to assess hazard, application of procedures to assess health and stability) and measurement of individual trees using scientific instruments such as a Resistograph measurements is subjective based on individual interpretation and can produce highly variable information. 254 High Street Pepper Trees December 29, 2011 Moorpark,CA Page 3 Structural Condition Rating System A—A healthy,sound and vigorous tree characteristic of its species with no apparent structural defects B—A healthy,sound and vigorous tree with visual signs of only minor structural problems such as codominant stems and dead twigs C —Although healthy in overall appearance there exists an abnormal amount structural problems such as small cavities and or pockets of decay in main stem and or scaffold branches D This tree is characterized by a high degree of structural problems such as large cavities, areas of decay, visual signs of wood decay fungi, dead or damaged roots, codominant stems with included bark, excessive trunk lean and or areas that display cracks in wood. Trees in this category also have defects that exceed the threshold of what is considered for a tree that can be expected to reasonably support itself. Observations and Details on trees of highest concern Photos depicting individual trees and specific defects are provided following the report. Tree#2 is a mature tree that displays a history of limb failure on west side of tree. There is a 12" + horizontal cavity and area of decayed wood at site of limb failure with a column of decay that runs down into the main stem. Wood strength in the wound area is significantly compromised and the remaining limb is at risk of failure. In order to reduce risk keep excess weight trimmed off lateral limbs. Tree#8 is an historic senescent tree. Although the tree appears to be healthy and displays average vigor with new shoot growth, it also contains severe structural defects that compromise its structural stability. Signs indicate a history of limb failure on the south side of the tree. The NW lower lateral limb contains a large wound site with cavities and pockets of decay that affect limb stability. A large cavity and area of decay was observed at the base of the trunk on the south side;the trunk of the tree measures 47 inches in diameter just above the soil and the cavity measures 41 inches in depth; in this case I would consider trunk stability severely compromised. The crown of the tree is unbalanced with the majority of its canopy to the north side the trunk. This tree contains severe structural defects with an estimated 6 inches of sound wood in the outer shell of the trunk in the area of the cavity. I believe this tree poses a high risk for structural failure and due to conditions of instability that cannot be reasonably mitigated the tree should be removed immediately. If the tree is to remain in place I recommend a root crown excavation and inspection,and possibly dill testing to measure decay/cavities. Tree#9 is an historic veteran tree that is senescent. Although the tree appears to be healthy and displays good vigor with average new shoot growth, it also contains severe structural defects. The trunk contains a large cavity and area of decay on the SW side approx.9' up from the ground,this is the site of a past limb failure or removal. Sounding of the trunk revealed a distinct hollow sound that indicates advanced internal decay/cavity. By use of a metal probe,multiple deep cavities were confirmed on the south side of the tree just above soil level. 255 High Street Pepper Trees December 29, 2011 Moorpark,CA Page 4 A cavity in the upper portion of the trunk on the SW side likely has column of decay/cavity running all the way to ground level. Clusters of winged insects on the base of the trunk have been visually identified,as subterranean termites and are an indication of dead decayed wood above and or below ground. Tree#9 contains severe structural defects such as cavities and decay in its main stem, which severely compromise its structural stability and its ability to reasonably support itself. I believe this tree poses a high risk for structural failure and due to conditions of instability that cannot be reasonably mitigated the tree should be removed immediately. Should you decide to keep the tree in place it is recommended that a root crown excavation and inspection be performed to help identify and measure defects and better assess risk. Tree#13 is an historic veteran tree that is senescent. Although the tree appears to be healthy and displays good vigor with abundant new shoot growth,it also contains severe structural defects that deem it unstable. There is a large area of deadwood on the lower south side of the trunk. Soft decayed wood and cavities were observed and detected in various areas around the lower trunk. Probing revealed a 31" deep cavity on the south side of the tree at the base of the trunk,a 26" deep cavity on the north side 3 feet above the ground,and a 19" deep cavity on the SE side at 6.5 feet above the ground. Due to the number and severity of defects I consider the stability of this tree to be extremely compromised. Tree#13 contains severe structural defects such as cavities and decay that seriously compromise its trunk and scaffold limb stability. I believe this tree poses a high risk for structural failure and due to conditions of instability that cannot be reasonably mitigated the tree should be removed immediately. Should you decide to keep the tree in place it is recommended that a root crown excavation and inspection be performed to help identify and measure defects and better assess risk. Keep leaf debris cleared from base of trunk to expose root collar. Tree#14 is a large mature senescent tree. Although the tree appears to be healthy and displays good vigor with new shoot growth, it also contains severe structural defects that seriously compromise it structural stability. There is a 13"deep cavity on the SE side of the trunk approx. 6 feet above the ground,an 18" deep cavity on the west side at approx. 6 feet above the ground, a 27" deep cavity on the west side at 12 inches above the ground,a 25" deep cavity on the north side and the base of the trunk, and several other areas of potential decay and internal cavities were detected higher up in the trunk through sounding. The sum of defects describes a tree with serious stability problems in the trunk,scaffold and smaller branches in the crown. Tree#14 contains severe structural defects such as cavities and decay that affect tree stability. I believe this tree poses a high risk for structural failure, and due to conditions of instability that cannot be reasonably mitigated the tree should be removed immediately. Should you decide to keep the tree in place I recommend root crown inspection and major heading of the canopy to reduce excess weight. 256 High Street Pepper Trees December 29, 2011 Moorpark,CA Page 5 Tree#30 is a 43" diameter historic veteran tree that is senescent. Although the tree appears to be healthy and displays good vigor with new shoot growth,it also contains severe structural defects that seriously compromise its structural stability. This tree has significant trunk lean to the east with the majority of its canopy on the east side of the trunk. The tree also displays a history of limb failure. There is a large cavity on the west side of the trunk at 7 feet above the ground,with additional signs of cavities and decay higher up on the trunk. A distinct hollow sound was detected on the west side of the trunk with a column of decay and a 26"-35" deep cavity running from the upper cavity to the ground. A cavity was also observed on the west of the tree at 12 inches above the ground. Tree#30 contains severe structural defects such as cavities and decay that create severe problems relating to trunk stability. I believe this tree poses a high risk for structural failure and due to conditions of instability that cannot be reasonably mitigated the tree should be removed immediately. Should you decide to keep this tree in place,I strongly recommend that it be headed back significantly to reduce excess weight in the canopy and help reduce risk. Tree#31 is a 42" diameter historic veteran tree that is senescent. Although the tree appears to be healthy and displays good vigor with new shoot growth,it also contains severe structural defects that seriously compromise its structural stability. The tree has codominant stems. There are two beehives in the tree on the east side of the trunk at 8' and 14' above the ground. The presence of bees prevented a thorough inspection of the tree. The tree contains a 23" deep cavity in the trunk just below the lower beehive. It is very likely that the site of the two hives and opening below all converge into one large cavity. Tree#31 contains severe structural defects such as cavities and decay creating serious problems and lack of stability in the main stem and large limbs. I believe this tree poses a high risk for structural failure and due to conditions of instability that cannot be reasonably mitigated the tree should be removed immediately. Should you decide to keep the tree in place,I strongly recommend that it be headed back significantly to reduce excess weight in the canopy and help reduce risk. Tree#32 is a 26" diameter historic tree that is senescent. The tree appears to be in good health but contains severe structural defects,and is one-sided with its entire canopy on the north side of the trunk. Tree#32 displays a history of limb failure on the south side. An 18" deep cavity was observed at the base of the trunk on the south side and another cavity was observed in the trunk at approx. 14-feet above the ground. This tree has serious problems relating to trunk stability. Due to an extremely unbalanced crown,history of limb failure and deep cavities in the trunk I believe this tree poses a high risk for structural failure,and due to conditions of instability that cannot be reasonably mitigated the tree should be removed immediately. Should you decide to keep the tree in place, I strongly recommend that it be headed back significantly to reduce excess weight in the canopy and help reduce risk. 257 High Street Pepper Trees December 29, 2011 Moorpark, CA Page 6 Tree#33 is a 35"diameter historic tree that is senescent. Although the tree appears to be healthy and displays good vigor with new shoot growth, it also contains severe structural defects that seriously compromise its trunk stability. The tree has codominant stems with a deep sunken area at approx. 9 feet on the south side of the trunk,which is an indication of defects or internal decay. A distinct hollow sound was detected on the SW side of the trunk at 7 feet above the ground. The tree also contains a 20" deep cavity at the base of the trunk on the SW side,a 25" deep cavity on the north side at the base of the trunk,a 17" deep cavity on the SW side at 6 feet above the ground, and a large area of decay on the south side of the trunk at 9 feet above the ground. Compounding factor result in a tree that is considered seriously unstable. Tree#33 contains severe structural defects such as cavities and decay. I believe this tree poses a high risk for structural failure and due to conditions of instability that cannot be reasonably mitigated the tree should be removed immediately. Should you decide to keep the tree in place,I strongly recommend that it be headed back significantly to reduce excess weight in the canopy and help reduce risk. Tree#35 is a 34" diameter historic veteran tree that is senescent. Although the tree appears to be healthy and displays good vigor with new shoot growth,it also contains severe structural defects that seriously compromise its structural stability in the main trunk. Several hollow decayed areas were detected in the lower trunk area through sounding. Cavities and decay were also observed in the lower south side of the trunk. There is a 37" deep cavity on the SW side of the tree at the base of the trunk, a 33" deep cavity on the east side at 1.5 feet above the ground,a 23" deep cavity 4 feet above the ground on the SE side of the trunk, and a large wound and cavity at 7 feet above the ground on the south side of the trunk. Tree#35 contains severe structural defects such as cavities and decay that affect stability of the main trunk. I believe this tree poses a high risk for structural failure and due to conditions of instability that cannot be reasonably mitigated the tree should be removed immediately. Should you decide to keep the tree in place, I strongly recommend that it be headed back significantly to reduce excess weight in the canopy and help reduce risk. Tree#36 is an historic senescent veteran tree and is probably the largest of the population. Based on foliage growth the tree appears to be fairly healthy but contains a huge cavity and area of decay on the south side of the trunk. There is a general hollow sound in the SW lh of the trunk when sounded and general area of sound wood is very thin. Wood inside the large cavity is soft,punky and rotted,indicating the presence of wood decay fungi. Compounding data is indicative of a tree with severe problems relating to trunk stability. Unfortunately the cavity and decay at the base of the trunk of tree #36 has advanced to the point that I believe the tree cannot reasonably support itself and poses a high risk for structural failure. I believe this tree poses a high risk for structural failure and due to conditions of instability that cannot be reasonably mitigated the tree should be removed immediately. Should you decide to keep the tree in place, I strongly recommend that it be headed back significantly to reduce excess weight in the canopy and help reduce risk. 258 High Street Pepper Trees December 29, 2011 Moorpark,CA Page 7 Tree#46 is a 41"diameter historic veteran tree that is also senescent. Although the tree appears to be healthy and displays good vigor with new shoot growth, it also contains severe structural defects that seriously compromise stability in the trunk and large scaffold limbs. There is a beehive in the south lateral limb at approx. 15 feet up in the tree. Multiple small cavities and pockets of decay observed in both the large N & S lateral limbs directly over High street. The tree also contains a large cavity on the east side of the trunk at 5.5 feet above the ground near the point of connection of the two large codominant scaffold limbs. There is also a cavity on the south side of the trunk with a column of decay that likely runs all the way to ground level also running upward into the north lateral limb. Tree#46 contains severe structural defects such as cavities and decay. I believe this tree poses a high risk for structural failure and due to conditions of instability that cannot be reasonably mitigated the tree should be removed immediately. Should you decide to keep the tree in place,I strongly recommend that it be headed back significantly (not less than 50%)to reduce excess weight in the canopy and help reduce risk. This tree has serious stability problems in the main trunk and large limbs and is at high risk for failure. Tree#49 has all but failed due to oak root rot disease and should be removed as soon as possible to eliminate the risk of unexpected structural failure. Root rot seriously affects the integrity of root and tree stability. Discussion It is unfortunate that these highly valued and revered trees cannot live forever. I stand very firm in my opinion that the specified trees pose a high and probable risk for structural failure and should be removed immediately. Should you choose to keep the trees in place,I highly recommend that they be headed back significantly to reduce crown size and weight in the canopy,this may reduce risk should a failure occur. Major cavities and areas of decay clearly identified in several of the trees are an indication that the trees stability and ability to reasonably support their selves is highly questionable. Based on the size of cavities,advanced level of decay and condition of the wood in the decayed areas,and the presence of wood decay pathogens structural failure is highly probable. The history of tree failures and removals in the area is also a telling story as to the future of these magnificent trees. Guidelines and recognized standards from the text"The Body Language of Trees" by Claus Mattheck 1994,use a formula referred to as t/r; the thickness of remaining wall t is divided by the external radius R as the ratio t/R. Studies showed that trees with a shell wall thickness to trunk radius ratio of less than .03 had a high incident of failure. Generally speaking this would mean that a tree that has a sound shell wall thickness measuring less than 1/3'the trunk radius is at high risk for failure,especially during high winds or storms. Another industry guideline is related to the size of open cavities. In the text "Tree Risk Assessment in Urban Areas" by Julian Dunster, it is written that a cavity opening measuring more than 30% of stem circumference is structurally unstable and at high risk for failure. 259 High Street Pepper Trees December 29,2011 Moorpark, CA Page 8 The problem with the trees that are recommended for removal is that they all have multiple compounding defects,and although a tree may have only one defect that falls into the high -risk category,it is the combination of multiple defects that is very concerning to me. The location of the trees being near a highly traveled road where vehicles are frequently parked,sidewalks for retail storefronts frequented by pedestrians are all high valued targets. A tree failure in this type of setting could result in catastrophic property damage, personal injury or death. It is possible but not recommended,that should the city or community decide to preserve some of the trees awhile longer I recommend that previous recommendations from Michael Mahoney's report regarding pruning be implemented. I do believe however that pruning recommendations should be implemented in an even more aggressive and timely manor to remove excess weight,and remove potentially hazardous limbs in the crown of the trees to reduce the risk and or damages should a failure occur. My inspection of the younger more recently planted peppers revealed clear signs and indications that the trees were planted improperly and may have root defects such as girdling roots. The root collars of the trees was not clearly visible in most cases and when the trunks were pushed slightly,excess movement was observed at the soil line indicating the trees have not sufficiently rooted/anchored into the ground. It is recommended that root crown excavation be performed on these trees to check for proper planting depth and root defects, and defective trees be replaced with good quality nursery stock. If left in place,trees with girdling roots will never properly anchor into the ground, will have future health problems,and be at risk of failure during high winds or storms. It was also noted that vehicles are parking within the dripline and near the trunks of pepper trees in the dirt lot west of the paved lot used for the Metrolink,and those at the west end of High street adjacent to the Mexican restaurant. Parking of vehicles within the critical root zone can have significant impacts on tree health due to soil compaction. It is recommended that protective fencing or some type of barrier be installed to prevent vehicles from parking in this area. A minimum protection zone of 15-20 feet from the trunk of these trees should be established. A thick layer of organic plant debris and applied mulch has built up around the base of the trunks on several of the large peppers. It is recommended that debris and excess mulch be removed to fully expose the root collars of the trees. Recommendations Due to a serious problem and lack in structural stability in the trunk and or limbs, it is my recommendation that pepper trees#8,9, 13, 14,30, 31,32, 35, 36,46 &49 be removed due to their high probability for structural failure,and the potential for such failure to result in major property damage,personal injury or death. 260 High Street Pepper Trees December 29, 2011 Moorpark,CA Page 9 Tree #49 immediately as it is failing due to incurable root rot disease. Remove plant debris and excess mulch from around the base of trunks of pepper trees as needed to fully expose the root collar. Excess build up of leaf debris at the base of the trunk can hold excess moisture,which can favor disease. Perform root collar excavation on the small most recently planted pepper trees to check for girdling or other root defects,and to check planting depth. Replace those tree found to be defective and correct soil grade around those to remain to fully expose the root collar. Install protective fencing on the south side of pepper trees adjacent to unpaved parking lot west of paved Metro link lot and those adjacent to the Mexican restaurant to prevent vehicles from parking on top of the root zone of the trees and compacting soil. A minimum 15-20 foot protection zone is recommended. To help mitigate risk,prune trees as required reducing excess weight and tension stress on large limbs and to reduce height as recommended in report the from Michael Mahoney dated December 2003. It is recommended that all trees be inspected and evaluated not less than once a year to identify and monitor defects,assess risk,and to provide maintenance recommendations. Conclusion Most of the historic veteran trees contain severe and sometimes multiple structural defects that have compromised their structural integrity and stability leaving them at risk of failure. Remove the (12) specified tree immediately to eliminate the risk of structural failure that could result in property damage,personal injury or death. It is recommended that trees to remain be inspected not less than once a year to assess risk associated with the defects, and to make recommendations to help mitigate risk and help maintain their condition. It should be noted that the study of trees is not an exact science and arboriculture does not detect or predict with any certainty. The arborist therefore is not responsible for tree defects or soil conditions that cannot be identified by a prudent and reasonable inspection. If you have any questions or require other services please contact me at the number listed below. Respectfully, Arbor Essence Kerry Norman ASCA, Registered Consulting Arborist#471 ISA Board-Certified Master Arborist #WE-3643B 261 Date: December 15, 2011 Arbor Essence Job name: High Street Peppers Tree Survey Moorpark, CA -ree # Description Structural Observations Risk level Recommendations Condition California pepper Mature tree. No visual decay or Prune to reduce end weight. B Low Drill test defect on lower (Schinus mol%) cavities. east side of trunk Mature tree. History of limb failure, Keep excess weight trimmed Z California pepper C decay/cavity at wound site. Moderate-High off Ig. lateral limbs Mature tree. No apparent or 3 California pepper B Low None at this time obvious defects Mature tree. Notable trunk lean to 4 California pepper B west. No apparent or obvious Low None at this time defects California pepper, Young tree. Minor trunk lean to High for future Replace tree with good 5 9" diameter C north. Defective root system, if girdled quality nursery stock. girdled Remove stakes Younger tree. Excessive trunk Check root structure and 6 California pepper, C movement at soil, defective root High for future replace with good quality 8" diameter system probable, root collar not if girdled nursery stock if needed, visible correct soil grade Younger recently planted. Planted California pepper, Correct soil grade to expose 7 11" diameter C too deep. Lack of buttress Low at present root collar formation Senescent Historic Veteran tree. Recommend removal due to California pepper, h conditions of instability that 8 38" diameter D Multiple severe structural defects, High cannot be reasonably cavities and decay mitigated Senescent Historic Veteran tree. Recommend removal due to California pepper, High to conditions of instability that 9 40" diameter D Multiple severe structural defects, extreme cannot be reasonably cavities and decay mitigated California pepper, Young mature tree. Minor lean to o 10 16" diameter B NW. One-sided with 90% of crown Low-Moderate None at this time on N side of trunk. Young but mature tree. Circling California pepper B Low None at this time girdling roots north side of trunk oung 1501 mature tree. NO apparent problems. Vehicle 2 California pepper B Low None at this time damage to limbs on street side of Senescent Historic Veteran tree. Recommend removal due to California pepper, High to conditions of instability that � 3 43" diameter D Multiple severe structural defects, extreme cannot be reasonably cavities and decay mitigated Senescent large mature tree. Recommend removal due to California pepper, High to conditions of instability that 14 25" diameter D Multiple severe defects, deep extreme cannot be reasonably cavities and areas of decay mitigated 262 Date: December 15, 2011 Arbor Essence Job name: High Street Peppers Tree Surve Moorpark, CA Structural -ree # Description Condition Observations Risk level Recommendations 15 California pepper A Young but mature tree Low None at this time Senescent Historic Veteran tree. History of Ig. limb failure E side of tree. Codominant stems. Several Maintenance prune to keep 16 California pepper C Moderate excess weight off large limbs small cavities and areas of decay on west side in crown of tree. 12" cavity at root collar Young tree. Excessive trunk Check root structure and movement at soil, poss. High for future replace with good quality 17 California pepper C defective/girdled root system, if girdled nursery stock if needed, planted too deep, root collar not correct soil grade visible 20 California pepper, B Young but mature tree. No Low None at this time 23" diameter apparent problems 21 California pepper, B Young but mature tree. No Low None at this time 21" diameter apparent problems Check root structure an er e California pepper, Young tree. Excessive trunk High for future replace with good quality 22 C movement at soil, poss. nursery stock if needed. 8" diameter defective/girdled root system if girdled Correct soil grade and Young tree. Excessive trunk California pepper, movement at soil, High for future Check root structure and 23 5" diameter B defective/girdled root system if girdled replace with good quality nursery stock if needed probable Young tree. Excessive trunk High Check root structure and 24 California pepper, B movement at soil, g for future replace with good quality 4.5" diameter defective/girdled root system if girdled probable, 4"-5" too deep nursery stock if needed Young tree. Planted too deep, may Check root system and A 25 California pepper, have girdled roots. Excessive Low at present replace tree if needed. 7" diameter movement at soil, girdled roots Correct soil grade to expose probable root collar Young tree. Excessive trunk California pepper, movement at soil, High for future Check root structure and 26 7" diameter B defective/girdled root system if girdled replace with good quality nursery stock if needed probable 27 California pepper B Young but mature tree. No Low Keep ground cover trimmed apparent problems back from trunk 2' min. Young but mature tree. No Keep ground cover trimmed 2$ California pepper B apparent problems Low back from trunk 2' min. Young tree. Excessive trunk Check root system and 29 California pepper, B movement at soil, poss. High for future replace tree if needed. 8" diameter defective/girdled root system, if girdled Correct soil grade to expose root collar buried root collar 263 Date: December 15, 2011 Arbor Essence Job name: High Street Peppers Tree Survey Moorpark, CA �ree # Description Structural Observations Risk level Recommendations Condition Senescent Historic Veteran tree. Multiple severe structural defects, Recommend removal due to 30 California pepper, D cavities and decay. Trunk lean to E High-extreme conditions of instability that 43" diameter cannot be reasonably with majority of crown of east side mitigated of trunk Senescent Historic Veteran tree. Recommend removal due to California pepper, Two cavities with beehives. conditions of instability that 31 42" diameter D Codominant stems. Large cavity in High-extreme cannot be reasonably main stem just below beehive mitigated Old mature senescent tree. Recommend removal due to California pepper, Multiple defects, cavities and conditions of instability that 32 26" diameter D decay. One-sided with entire High-extreme cannot be reasonably crown on N side of trunk mitigated Old mature senescent tree. Recommend removal due to 33 California pepper, D Codominant stems. Multiple High conditions of instability that 35" diameter defects and deep cavities in main cannot be reasonably trunk mitigated Young tree. Excessive trunk Check root system and 34 California pepper, B movement at soil, High for future replace tree if needed. 8" diameter defective/girdled root system if girdled Correct soil grade to expose probable. Planted too deep root collar Recommend removal due to Senescent Historic Veteran tree. High to conditions of instability that g y 3 5 34" diameter California pepper, D Multiple severe structural defects, extreme cannot be reasonably cavities and decay mitigated Senescent Historic Veteran tree. Multiple severe structural defects, Recommend removal due to California pepper, High to conditions of instability that 36 D cavities and decay. Huge cavity 59 diameter and area of decay lower trunk, 112 extreme cannot be reasonably trunk hollow mitigated California pepper, 37 2" diameter B Newly planted tree Low None at this time Young but mature tree. Beginning Remove concrete from 38 California pepper B to crack concrete at base of trunk Low around base of trunk to provide 2' clearance Young tree. Excessive trunk Check root structure and 39 California pepper, B movement at soil, defective root High for future replace with good quality 5" diameter system probable, root collar not if girdled nursery stock if needed, visible correct soil grade Young but mature tree. Root collar Check soil grade and correct 40 California pepper B not clearly visible Low as needed to expose root collar Young but mature tree. Root collar 41 California pepper B not clearly visible Low as needed to expose root 42 California pepper No tree in this location/space 264 Date: December 15, 2011 Arbor Essence Job name: High Street Peppers Tree Surve Moorpark, CA ree # Description Structural Observations Risk level Recommendations Condition Historic Veteran tree. Few small cavities S/E side of tree. Minor 43 California pepper C dieback. No major defects Low-moderate None at this time observed Senescent Historic Veteran tree. No major defects observed. Small Recommend drill test in main 44 California pepper C cavities in large limbs. Possible Moderate trunk, and inspection of internal decay detected through cavities higher up in tree sounding Young tree. Excessive trunk Check root system and 45 California pepper, B movement at soil, poss. High for future replace tree if needed. 8" diameter defective/girdled root system, if girdled Correct soil grade to expose root collar buried root collar Senescent Historic Veteran tree. High to Recommend removal due to California pepper, Multiple severe structural defects, extreme for conditions of instability that 46 41" diameter cavities and decay. Growing over cannot be reasonably street, very thin shell wall limb failure mitigated Senescent Historic Veteran tree. Large cavity lower N/W side of Maintenance prune to keep 47 California pepper C Moderate-high excess weight off large trunk, deep cavity S/E side at base of trunk. limbs. Young tree. Root collar not clearly Check soil grade and correct 48 California pepper B Low as needed to expose root visible, may be planted too deep collar Senescent Historic Veteran tree. Cavities in large lateral limbs Recommend removal due to D 49 California pepper, above street. Potential internal Moderate-high conditions of instability that 51" diameter decay detected through sounding. cannot be reasonably Tree failing due to armillaria root mitigated rot disease Young mature tree. Trunk lean to 50 California pepper B S/W Low None at this time Young mature tree. No apparent $1 California pepper B Low None at this time problems Young mature tree. No apparent 52 California pepper B Low None at this time problems Recommended tree removals 265 Y '9 k j h Y. 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