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HomeMy WebLinkAboutArborist Report - Aberdeen Tree Plan Report Arborist Report 2525 Aberdeen Ave NE Renton, WA January 27th, 2016 Revised February 12th, 2016 American Forest Management 2/12/2016 Table of Contents 1. Introduction .............................................................................................................. 1 2. Description ............................................................................................................... 1 3. Methodology ............................................................................................................ 1 4. Observations ........................................................................................................... 2 5. Discussion ............................................................................................................... 2 6. Tree Retention ......................................................................................................... 3 7. Tree Replacement .................................................................................................. .3 8. Tree Protection Measures…………………………………………………………………4 Appendix Site/Tree Photos – pages 5 – 11 Tree Summary Table - attached Tree Plan Map – attached 2525 Aberdeen Ave NE Arborist Report Page 1 American Forest Management 2/12/2016 1. Introduction American Forest Management, Inc. was contacted by Bill Hegger, and was asked to compile an ‘Arborist Report’ for two parcels located within the City of Renton. The proposed 4-Lot short plat encompasses the property at 2525 Aberdeen Ave NE. Our assignment is to prepare a written report on present tree conditions, which is to be filed with the preliminary permit application. This report encompasses all of the criteria set forth under City of Renton code section 4-4-130. The tree retention requirement is 30% of significant trees. Date of Field Examination: January 25th, 2016 2. Description 54 significant trees were identified and assessed on the property. These are comprised of a mix of native species and planted ornamental species. According to City of Renton code, a significant tree is a “tree with a caliper of at least six inches (6"), or an alder or cottonwood tree with a caliper of at least eight inches (8"). Trees qualified as dangerous shall not be considered significant. Trees planted within the most recent ten (10) years shall qualify as significant trees, regardless of the actual caliper.” A numbered aluminum tag was placed on the lower trunks of the subject trees by the surveying crew. These numbers were used for this assessment. Tree tag numbers correspond with the numbers on the Tree Summary Tables and copy of the attached site survey. There is one neighboring tree with a drip line that extends over the property line . 3. Methodology Each tree in this report was visited. Tree diameters were measured by tape. The tree heights were measured using a Spiegel Relaskop. Each tree was visually examined for defects and vigor. The tree assessment procedure involves the examination of many factors:  The crown of the tree is examined for current vigor. This is comprised of inspecting the crown (foliage, buds and branches) for color, density, form, and annual shoot growth, limb dieback and disease. The percentage of live crown is estimated for conifer ous species only and scored appropriately.  The bole or main stem of the tree is inspected for decay, which includes cavities, wounds, fruiting bodies of decay (conks or mushrooms), seams, insects, bleeding, callus development, broken or dead tops, structural defects and unnatural leans. Structural defects include crooks, forks with V-shaped crotches, multiple attachments, and excessive sweep.  The root collar and roots are inspected for the presence of decay, insects and/or damage, as well as if they have been injured, undermined or exposed, or original grade has been altered. Based on these factors a determination of viability is made. Trees considered ‘non-viable’ are trees that are in poor condition due to disease, extensive decay and/or cumulative structural defects, which exacerbate failure potential. A ‘viable’ tree is a tree found to be in good health, in a sound condition with minimal defects and is suitable for its location. Also, it will be wind firm if isolated or left as part of a grou ping or grove of trees. A ‘borderline’ viable tree is a tree where its viability is in question. These are trees that are beginning to display symptoms of decline due to age and or species related problems. Borderline trees are not expected to positivel y contribute to the landscape for the long-term and are not recommended for retention. The attached site plan/tree map indicates the viability of the subject trees. 2525 Aberdeen Ave NE Arborist Report Page 2 American Forest Management 2/12/2016 4. Observations The subject trees are comprised of a mix of native and planted species. The native tree species are primarily in the access easement and in Lot 1. Specific tree information can be found on the attached tree table. Douglas-fir trees The Douglas-fir trees vary in age and condition. Some of the common defects incl ude broken tops, crooked trunks and small live crowns. The Douglas-fir trees in Lot 1 are growing very closely together , a few have poor trunk taper and small crowns as a result of this. Additionally, many of the trees exhibit signs of suppression. Big leaf maple trees The big leaf maple trees on the property are in fair to poor condition. Structural defects such as co-dominant stems with poor attachment, crooks in the trunk and leaning trunks were common. Decay was also observed in a few of the maple trees. Pacific madrone trees The pacific madrone trees on the property are generally in decline. Concerning defects observed included stem cankers and branch dieback. The pacific madrone trees range from fair to fair -poor condition. Western red cedar trees The western red cedars on the property are young and have good vigor. The two western red cedars are both in good condition and are viable. Other concerning trees Tree #115 is a European white birch planted in the center of the property. This tree has an over exposed root flare. This tree additionally has significant trunk decay. This tree is in poor condition and is non -viable. Tree #117 is a flowering cherry tree planted in the center of the property. This tree has a co -dominant stem that forks 5’ from the base of the trunk. The attachment between the two main stems is a weak, v shaped attachment and there is decay at the area of attachment. This tree is in poor condition and is non-viable. Tree #118 is a grand fir on the south edge of the property. This tree has moderate dieback in over 30% of the crown. No concerning defects were observed on the trunk of the tree. This tree is in decline and is in fair to poor condition. The subject tree is borderline viable. Tree #122 is a cherry plum in the center of the property. This tree has a large, visible, column of decay in 8 feet of the lower trunk. This tree is in poor condition and is non-viable. Neighboring Trees Tree #201 is a young lodge pole pine north of the property line. This tree has a full crown and good taper. No concerning defects were observed. 5. Discussion The grade in most of Lot 1 will be lowered by a few feet to match the grade of the rest of the property. Grade changes should not occur within the limits of disturbance for trees that will be retained. Lowering the grade near trees removes and damages roots, which reduces the ability of the tree to absorb water and nutrients and maintain vigor. Grade changes can also reduce the structural integrity of trees. Finished landscaping work within the drip-lines of retained trees shall maintain existing grades and not disturb fine root mass at the ground surface. Finish landscape with beauty bark or new lawn on top of existing grade. Add no more than 2” to 4” of mulch/beauty bark or 2” of composted soil to establish new lawn. The extent of drip-lines (farthest reaching branches) for the subject trees can be found on the tree summary tables at the back of this report. These have also been delineated on a copy of the site survey for viable/healthy trees proposed for retention. The information plotted on the attached survey plan may need to be transferred to 2525 Aberdeen Ave NE Arborist Report Page 3 American Forest Management 2/12/2016 a final tree retention/protection plan to meet City submittal requirements. The trees that are to be removed shall be shown “X’d” out on the final plan. The Limits of Disturbance (LOD) measurements can also be found on the tree summary table. This is the recommended distance of the closest impact (soil excavation) to the trunk face. These should be referenced when determining tree retention feasibility. The LOD measurements are based on species, age, condition, drip - line, prior improvements, proposed impacts and the anticipated cumulative impacts to the entire root zone. Tree Protection fencing shall be located beyond the drip -line edge of retained trees, and only moved back to the LOD when work is authorized. There are no major conflicts concerning neighboring trees. Tree #201 is on the north perimeter and with tree protection fencing, no major root damage is expected. 6. Tree Retention A total of 54 significant trees were identified on the subject property. Five of the significant trees are in poor condition and three are in fair -poor condition. These eight borderline to non-viable trees were not included in the tree calculation. Landmark trees and tree groves were prioritized when selecting trees for retention, per the City of Renton tree code 4-4-130. Tree Calculation based on 46, healthy, viable, significant trees Viable Trees proposed for removal – 30 (65%) Viable Trees proposed for retention – 16 (35%) 7. Tree Replacement Replacements trees may be required. Consult your city planner for tree replacement requirements. All replacement trees are to be planted on site. For planting and maintenance specifications, refer to Section 4-4- 130 of the Renton Tree Ordinances. Tree Type Removal Retained Total Landmark # 2 3 5 Landmark % 40% 60% 11% Significant # 28 13 41 Significant % 68% 32% 89% Total # 30 16 46 Total % 65% 35% 100% 2525 Aberdeen Ave NE Arborist Report Page 4 American Forest Management 2/12/2016 8. Tree Protection Measures The following guidelines are recommended to ensure that the designated space set aside for the preserved trees are protected and construction impacts are kept to a minimum.  Tree protection barriers shall be initially erected at 5’ outside of the drip-line prior to moving any heavy equipment on site.  Tree protection fencing shall only be moved where necessary to install improvements, but only as close as the Limits of Disturbance, as indicated on the attached plan.  Excavation limits should be laid out in paint on the ground to avoid over excavating.  Excavations within the drip-lines shall be monitored by a qualified tree professional so necessary precautions can be taken to decrease impacts to tree parts. A qualified tree professional shall monitor excavations when work is required and allowed up to the “Limits of Disturbance”.  To establish sub grade for foundations, curbs and pavement sections near the trees, soil should be removed parallel to the roots and not at 90 degree angles to avoid breaking and tea ring roots that lead back to the trunk within the drip-line. Any roots damaged during these excavations should be exposed to sound tissue and cut cleanly with a saw. Cutting tools should be sterilized with alcohol.  Areas excavated within the drip-line of retained trees should be thoroughly irrigated weekly during dry periods.  Preparations for final landscaping shall be accomplished by hand within the drip -lines of retained trees. Plantings within the drip lines shall be limited. Large equipment shall be kept outside of the tree protection zones. There is no warranty suggested for any of the trees subject to this report. Weather, latent tree conditions, and future man-caused activities could cause physiologic changes and deteriorating tree condition. Over time, deteriorating tree conditions may appear and there may be conditions, which are not now visible which, could cause tree failure. This report or the verbal comments made at the site in no way warrant the structural stability or long term condition of any tree, but represent my opinion based on the observations made. Nearly all trees in any condition standing within reach of improvements or human use areas represent hazards that could lead to damage or injury. Please call if you have any questions or I can be of further assistance. Sincerely, Kelly Wilkinson ISA Certified Arborist #PN-7673A ISA Tree Risk Assessment Qualified 2525 Aberdeen Ave NE Arborist Report Page 5 American Forest Management 2/12/2016 Photos Tree #103, #102 and #101 – Douglas-fir trees on east side of Lot 4 Tree #110 – pacific madrone with co-dominant stems and stem cankers 2525 Aberdeen Ave NE Arborist Report Page 6 American Forest Management 2/12/2016 Lot 1 Tree #115, #116 and #117 – ornamental trees planted in Lot 3 and 4 2525 Aberdeen Ave NE Arborist Report Page 7 American Forest Management 2/12/2016 Tree #115 – European white birch with an over exposed root flare Tree #117 – flowering cherry with decay and co dominant stems 2525 Aberdeen Ave NE Arborist Report Page 8 American Forest Management 2/12/2016 View of Lot 1 from the east Tree #118 – grand fir with moderate limb dieback 2525 Aberdeen Ave NE Arborist Report Page 9 American Forest Management 2/12/2016 Tree #120 – black oak Tree #122 – cherry plum with severe decay 2525 Aberdeen Ave NE Arborist Report Page 10 American Forest Management 2/12/2016 Tree #127 – big leaf maple, co dominant stems with poor attachment South end of Lot 1 2525 Aberdeen Ave NE Arborist Report Page 11 American Forest Management 2/12/2016 Tree #146 – pacific madrone with Nattrassia canker South perimeter of Lot 1 and 2 Tree Summary Table American Forest Management, Inc. For:2525 Aberdeen Ave NE Date:1/25/2015 City of Renton Inspector:Wilkinson Tree/DBH Height Tag #Species (inches)(feet)Condition Viability Comments Proposal N S E W 129 Douglas-fir 12 84 8 5 8 fair viable remove 130 Douglas-fir 12 85 5 5 17 fair viable remove 131 Douglas-fir 15 86 9 15 fair viable remove 132 Douglas-fir 10 41 8 12 fair viable suppressed remove 133 Douglas-fir 12 88 8 9 fair viable remove 134 Douglas-fir 6 31 8 3 2 10 fair viable suppressed remove 135 Douglas-fir 14 90 10 7 3 fair viable remove 136 Douglas-fir 6 42 3 4 12 2 fair viable remove 137 Douglas-fir 16 92 6 5 15 fair viable remove 138 Douglas-fir 10 51 7 6 2 8 poor non-viable broken top, 30% live crown remove 139 Douglas-fir 10 76 3 7 4 3 fair viable remove 140 Lombardy poplar 16 90 6 6 5 7 fair viable remove 141 Douglas-fir 7 68 7 6 4 4 fair viable remove 142 big leaf maple 7 47 8 6 9 3 fair viable remove 143 Douglas-fir 8 62 8 / 5 0 / 5 15 / 5 fair viable suppressed retain 144 Douglas-fir 20 95 7 / 10 13 / 10 11 / 10 14 / 10 fair viable retain 145 Douglas-fir 9 51 2 / 5 10 / 5 7 / 5 4 / 5 fair viable retain 146 pacific madrone 13 48 fair-poor borderline decay, 50% dieback remove 147 Lombardy poplar 10 58 2 / 5 4 / 5 4 / 5 fair viable retain 148 Lombardy poplar 9 62 3 / 5 4 / 5 4 / 5 fair viable retain 149 Douglas-fir 8 30 8 7 11 2 fair-poor borderline broken top, small live crown remove 150 Douglas-fir 17 95 10 / 8 11 / 8 15 / 8 12 / 8 fair viable retain 151 Douglas-fir 12 60 4 / 6 16 / 6 10 / 6 fair viable retain 152 Douglas-fir 11 58 7 / 6 17 / 6 fair viable 10 deg lean E retain 153 western larch 6 32 7 / 5 8 / 5 6 / 5 good viable retain 154 Lombardy poplar 37 101 6 / 15 7 / 15 7 / 15 fair viable landmark retain 201 lodgepole pine 9 32 6 / 5 good viable Drip-Line and Limits of Disturbance measurements from face of trunk Drip-Line/Limits of Disturbance (feet) Trees on neighboring properties - Drip-line and Limits of Disturbance measurements from property lines Neighboring Tree Tree Summary Table American Forest Management, Inc. For:2525 Aberdeen Ave NE Date:1/25/2015 City of Renton Inspector:Wilkinson Tree/DBH Height Tag #Species (inches)(feet)Condition Viability Comments Proposal N S E W 101 Douglas-fir 31 90 11 / 12 16 / 12 11 / 12 22 / 12 fair viable broken top, landmark retain 102 Douglas-fir 23 65 8 / 10 12 / 10 18 / 10 10 / 10 fair viable crooked trunk retain 103 Douglas-fir 32 115 9 / 12 11 / 12 8 / 12 15 / 12 good viable landmark retain 104 western red cedar 6 22 6 5 6 5 good viable remove 105 Douglas-fir 36 107 18 20 22 good viable landmark remove 106 big leaf maple 12, 20 61 9 9 12 poor non-viable one stem dead, the other declining remove 107 lodgepole pine 8 36 8 9 8 11 fair viable remove 108 western red cedar 6 28 6 8 10 fair viable remove 109 Douglas-fir 17 63 11 11 12 fair viable dieback remove 110 pacific madrone 21 46 14 9 22 fair viable decay, 10% dieback, forks at 5'remove 111 pacific madrone 13 52 2 fair viable 20% dieback remove 112 Douglas-fir 6 26 8 9 10 fair viable remove 113 Douglas-fir 17 87 13 8 12 fair viable remove 114 Douglas-fir 16 91 14 14 8 fair viable remove 115 European white birch 9 35 11 6 10 12 poor non-viable over exposed root flare, decay remove 116 honey locust 10 39 8 18 12 8 fair viable over exposed root flare remove 117 flowering cherry 16 37 14 16 12 12 poor non-viable severe decay, forked trunk remove 118 grand fir 41 104 18 21 18 fair-poor borderline severe dieback remove 119 giant sequoia 11, 11 46 8 / 10 6 / 10 10 / 10 fair viable forks at 1'retain 120 black oak 25 76 25 21 27 fair viable retain 121 honey locust 9 29 0 / 5 0 / 5 0 / 5 fair viable leans S retain 122 cherry plum 20 27 poor non-viable severe decay remove 123 Douglas-fir 24 96 11 / 10 12 / 10 good viable remove 124 big leaf maple 8 34 20 / 5 0 / 5 0 / 5 24 / 5 fair viable crooked, leans NW remove 125 Douglas-fir 14 59 13 5 8 5 fair viable crook at 7'remove 126 big leaf maple 11 58 7 3 16 12 fair viable remove 127 big leaf maple 12, 6, 14 61 18 16 6 17 fair viable forks at 2', poor attachment remove 128 Douglas-fir 17 88 9 11 18 fair viable remove Drip-Line and Limits of Disturbance measurements from face of trunk Drip-Line/Limits of Disturbance (feet) Trees on neighboring properties - Drip-line and Limits of Disturbance measurements from property lines