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RevisedArboristReport.pdfApril 8, 2015 Kernen Lien Senior Planner City of Edmonds, 121 5th Avenue North, Edmonds, WA 98020 Kent Halverson 6615 214th Ave NE Redmond, WA 98053 Re: Meadowview Estates Tree cutting @ 15610 & 15620 72nd Ave West Dear Mr. Lien: I was contacted by Mr. Halverson on March 30th and asked to review a letter dated March 26th, 2015 from the City of Edmonds regarding several violations of the City's tree cutting regulations.* He retained me to perform a site visit and a response to the letter. On April 3rd, 2015, I visited the site and spent several hours tagging all the trees impacted by the pruning and assessing whether damage had occurred to the native vegetation. In summary I found the following: • Nineteen (19) trees of varying sizes were pruned or topped • One (1) tree has been made non-viable as a result of topping • Eighteen (18) trees are viable and will recover • Ground cover was not significantly damaged On October 19th, 2015, I revisited the site and found it much improved. New photos and table are highlighted in yellow. I have amended my original assessment to the following: • Nineteen (19) trees of varying sizes were pruned or topped • All are expected to survive • Ground cover was not significantly damaged I have included a detailed report of my findings. If you have any questions please contact me; I can be reached at 425.890.3808 or by email: sprjnce2fJ _ aol.corn. Warm regards, Susan Prince Creative Landscape Solutions ISA Certified Arborist: PNW: 1481-A TRAQ/TRACE Certified: #418 17518 NE 119th Way Redmond, WA 98052 Assignment: I was contacted by Mr. Halverson who requested I visit the site of a proposed short plat at 15610 & 15620 72nd Ave West, in Edmonds to assess whether trees pruned in the previous few weeks on the west side of the slope would recover of if they had been irreparably damaged. At that time, I examined and documented the slope vegetation to assess the health of the plants and to make recommendations for ensuring that viability of the tree and plant material. Personal qualifications, scope of work and methodology: To evaluate the trees and prepare the report, I drew on my formal college education in botany, preparation and training used to obtain my ISA certification in addition to my certification as a Tree Risk Assessor. I have been an ISA Certified Arborist for over fifteen years and have been TRACE/TRAQ certified for four years. I followed protocol delineated by the International Society of Arboriculture (ISA) for Visual Risk Assessment (VRA). By doing so, I am examining each tree independently as well as collectively as groups or stands of trees provide stability and can lower risk of independent tree failure. This scientific process examines tree health (e.g. size, vigor, and insect and disease process) as well as site conditions (soil moisture and composition, amount of impervious surfaces surrounding the tree etc.) Introduction: Identifying and managing the risks associated with trees is still largely a subjective process. Since the exact nature of tree failures remains largely unknown, our ability as scientists and arborists to predict which trees will fail and in what fashion remains limited. As currently practiced, the science of hazard tree evaluation involves examining a tree for structural defects, including genetic problems, those caused by the local environmental that the tree grows in and those attributed to man (pruning etc.). The assessment process involves evaluating three components: 1) a tree with the potential to fail, 2) an environment that may contribute to that failure, and 3) a person or object that would be injured or damaged (the target). By definition a defective tree cannot be considered hazardous without the presence of a target. All trees have a finite life -span though it is not pre-programmed internally in the same manner as annual plantings. As trees age they are less able to compartmentalize structural damage following injury from insects, disease or pruning. Trees in urban settings have a shorter life span than trees grown in an undisturbed habitat. Different species of trees grow differently. Evergreen trees have a "reputation" of growing slowly and defensively. These trees allocate a high proportion of their resources to defending themselves from pathogens, parasites and wounds. As a rule, trees with this type of growth tend to be long lived. Though like all other living things, they have a fairly predictable life span. Examples of this type of tree include the northwest Pseudotsuga menziesii - Douglas fir, and Thuja plicata - Western red cedar. Deciduous trees are trees that annually shed leaves or needles. These trees have a tendency to grow quickly and try to "outgrow" problems associated with insects, disease and wounds. They allocate a relatively small portion of their internal resources to defense and rely instead upon an ability to grow more quickly than the pathogens which infect them. However, as these trees age, their growth rate declines and the normal problems associated with decay begins to catch up and compromise the tree's structural integrity. Examples of this type of tree include Salix, Populus and Alnus. Knowledge of the growth and failure patterns of individual tree species is critical to effective hazard analysis. Species vary widely in their rates of failure. The hazard tree evaluation rating system used by most arborists was developed by the Colorado Urban Forest Council and recognizes this variation in species failure and includes a species component as part of the overall hazard evaluation. Site Observations: The site is a 2.2 acre site that "faces" to the west. There is a steep slope on the western portion of the property. Al Photo looking west at the slope drop off Offsite trees Potentially Impacted by Development: None Method's used to determine tree location and tree health: Trees were identified previously by numbered aluminum tags attached to the western side of the tree. All of the trees on site were examined using the Matheny and Clark' criteria for determining the potential hazard of trees in an urban environment as well as the Tree Risk Assessment in Urban Areas and The Urban/Rural Interface by Julian Dunster2. The tree diameter was measured using an aluminum "diameter tape measure." Tree canopy was measured from longest branch to longest branch with a cloth tape measure secured by a stake. Spreadsheet Legend: Tree tag #:........ Numbered aluminum tags attached to the trees in the field DBH:........ Diameter of the tree measured at 42" above grade Dripline Radius: ........ Measurement in feet of the tree canopy from tree trunk to outermost branch tip Health: ........ A measurement of overall tree vigor and vitality rated as excellent, good, and fair or poor based on an assessment of crown density, leaf color and size, active callusing, shoot growth rate, extent of crown dieback, cambium layer health, and tree age • Excellent: Tree is an ideal specimen for the species with no obvious flaws • Good: Tree has minimal structural or situational defects • OK: Minimal structural issues with poor • Fair: Tree has structural or health issues that predispose it to failure if further stressed • Poor: Tree has significant structural and/or health issues. It is exempt from total tree count. Defects/Concerns: ........a measure of the tree's structural stability and failure potential based on assessment of specific structural features, e.g., decay, conks, co -dominant trunks, included bark, abnormal lean, one-sided canopy, history of failure, prior construction impact, pruning history, etc. Proposed action: • Reta i n • Remove due to viability Species ID: ........ Spreadsheet contains common names of trees which correspond to scientific names as follows: • Apple: Malus sp. • American sycamore: Plantanus occidentalis • Austrian pine: Pinus nigra • Bigleaf maple: Acer macrophyllum • Birch: Betula nigra • Bitter Cherry: Prunus emarginata • Blue atlas cedar: Cedrus atlantica 'Glauca' • Cedar: Thuja plicata • Cherry: Prunus sp. • Dawn redwood: Chamaecyparis nootkatensis • Deodora cedar: Cedrus deodara • Colorado blue spruce: Picea pungens • Cottonwood: Populus trichocarpa • Dogwood: Cornus nuttaNii • Douglas fir: Pseudotsuga menziesii • English laurel: Prunus laurocerasus • Filbert: Corylus avellana var. • Grand fir: Abies grandis • Hemlock: Tsuga hetrophylla • Holly: Ilex aquifolium • Japanese maple: Acer palmatum • Leylandii cypress: Cupressocyparis leylandii • Lodgepole pine: Pinus contorta • Mountain ash: Sorbus americana • Pear: Pyrus sp. • Plum: Prunus • Red Alder: Alnus rubra • Red maple: Acer rubrum • Walnut: Juglans sp. • Western red cedar: Thuja plicata • Weeping Alaska cedar: Metasequoia glyptostrobides • White pine: Pinus strobus m ° ,E v° v �o E U -o m E m fo o-o� Ln .. ;. 3 (o fo � = a) a)- n- �.D� C U C M N fv v N �-0 fCo fJ fo r-1 Ln N C 4- fo V V) fo a) +� �_ V n t 4 U U a) a D E) -V u r�LO O N u EO .0 C CL a s (L�o Qo �� a oiaa)) �� a) o En aj >4J o E mew -0o E �'E o o° 3 u ro fo L C v a) L fa V) L a-' L d VI a) E U a U s v cn o o E o,E o- •� V E = oio'ac u Y a) O En -0 � 0� °o E > > L L a) QmE v 2 L ° in O !Z a) O> V) '0 L- r�o L E L @�-3+I :. 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U U) V) L a) w CU-0 L a) L a) L W u _ C -0 4 f6 Q) _� fu �_ _� v bio CL o E fa) (b aj OC a OO E C a) a N a) O) O 00 i 00 M r*4 l0 rl 00 V) f6 cn N a) H 01 01 l0 l0 l0 C L C 7 a) 0 N to N 00 m o a a N .ti ry m Photo documentation April 3, 2015: (700 Alder) 699 Bigleaf (698 Grand fir) 694 Bigleaf clump (693 Bigleaf) 623 Red alder 693 Bigleaf maple, limbs left intact 700: red alder clump 694: Bigleaf maple multi -trunks, some with advanced decay, normal and wound 974 topped at 25', decay at root crown. Close up of decay cavity and previous failures 973 Co -dominant leaders, one decayed 676 Red alder, torn leader from topping 681: Red alder, decay at root crown Photo documentation October 19, 2015 Ground cover regrowth New growth on Cherry Grand fir: approx. 14" new growth Observed vegetation species: Common name Botanical name Viable? Native? wwww.... Doualas fir Pseudotsuga menziesii _ WW... Yes Yes ....._ WWW Bigleaf maple Acer macrophvllum Yes Yes Red alder Alnus rubra Yes Yes Western Red Cedar Thuia nlicata Yes Yes Bitter cherry Prunus emarginata No Yes Cascara Rhamnus purshiana Yes Yes English holly Ilex aquifolium Yes No Himalavan blackberry Rubus discolor Yes No Salah Gaultheria shalon Yes Yes Sword fern Polvstichum munitum _ Yes Yes ........ _. Native blackberry Rubus ursinus Yes Yes Hazelnut Corvlus cornuta Yes Yes Lady's mantle Alchemilla vulgarisYes Yes Bleeding heart Dicentra spectabilis Yes Yes Salmon berry Rubus spectabilis Yes Yes Horsetail Eauisetum Yes Yes Discussion and Conclusion: On April 3rd, 2015 I examined the two sites noted above to determine the extent to which tree cutting had taken place, whether the trees growth remaining below the cuts were viable, and whether or not the vegetation growing on the slope had suffered any permanent damage. The view corridor is framed by native trees and vegetation. Above the slope and on the site to the west the site had a number of climax species trees growing on it (Douglas fir, Western red cedar) while the view corridor had only pioneer species growing on it. This indicates that the ecosystem of the slope is has been more recently or more consistently disturbed (there was a slide in 1997), followed by site improvements to control drainage. I found that small diameter clumps of trees (bigleaf maples and red alders) were located primarily at the top of the slope. These were cut cleanly at approximately 3-4' from the surface. As I travelled downhill to the west, the trees that had been topped, were larger in diameter (even in clumps) and were climbed and topped at higher heights. It is fortunate that this was the case, the small diameter clumps will continue to sprout more buds from the base of the tree, as well as from the area under the cuts where dormant lateral buds lie. The pruning of the three small diameter clumps will stimulate growth through the spring and early summer, no permanent damage was done. However, the trees should be thinned in the future of competing trunks to ensure healthy attachments. Likewise the larger trunk diameter clumps of Red alder and Bigleaf maples located mid - slope were cut at approximately 18'; most contained branches that will continue to sprout - these trees are moderately impacted. As pioneer species trees, they are almost always in the process of regenerating new trunk and limbs as their wood decays readily. As can be seen in the photographs, many of these trees contain significant amounts of decay already - this is typical of the species and new trunks are already growing from the base. Overall, the least impacted of the trees by the cutting, are the trees located near the base of the slope (the furthest west of the bluff) which have been cut to heights of about 25-30'. These trees retain many of their branches which will continue to grow and remain viable. There is one (1) tree that was negatively impacted by the pruning. Tree #624 is a Bitter cherry with a DBH of 10" and although it easily produces waterspouts in response to broken limbs, this is an older tree with no branches to support photosynthesis. It may recover, but more likely it will not. On the southwest site collectively, the trees were noted to have been limbed in the past and most of the trees are climax species trees that do not replace limbs. These trees do not appear to have been recently pruned; they are growing in well protected groves, do not appear to have any unusual structural flaws nor are they pruned to a point that they have a new "low live crown ratio". There does not appear to have been any attempt made to grub out vegetation, much of what I identified was perennial and is growing quickly. Ground cover is returning with Himalayan blackberries recovering most rapidly, when some of the leaves drop during winter months, remaining ground cover starts will likely be more visible. Strong new growth is visible on all the trees. Recommendation: Monitor the site at 6 months and 1 year to replace any material that the pruning killed, some of the trees were in fair condition to begin with and should they die, should remain on site as an animal habitat. The decrease in the song bird population over recent years is a result of the removing of dead wood. Continue to monitor the new growth every six months for a year to determine whether it is prudent to reshape any tree crowns. I am reluctant to recommend replanting of any kind at this time in order to see how the site responds. My experience on the slope has lead me to believe that the process of replanting (gaining access on the steep slope) may damage more native growth than any replanting will improve the site unless it is done in fall.