DNS BLD2021-1719+TRA+12.21.2021_1.19.54_PM+2586070LOT 2
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September 14, 2021
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Kayla Clark Nichols
Project Coordinator
CM
Select Homes, Inc.
0
206.963.3365
N
Site: 7918 203rd St SW
N
Edmonds, WA 98029
N
TPN: 27041900112700
ti
Size of area: .51 acres
Re: RFI Dated August 241h, 2021
Dear Kayla:
RECEIVED
Dec 28 2021
CITY OF EDMONDS
DEVELOPMENT SERVICES
DEPARTMENT
BLD2021-1719
Creative Landscape Solutions 1
7918 203rd St SW
Thank you for requesting my services. On April 5th, 2021, we visited the site located above in
Edmonds, WA to perform a Level 2 Tree Risk Assessment (TRA) for all onsite trees as well as offsite
trees with driplines that extend over the site. The information gathered and included in this report is
necessary to apply for a short -plat permit.
In summary:
Tree Density Calculations
Total number of onsite trees
35
Total number of non -viable trees
4
Total number of viable trees
31
Total number of trees removed for site improvements
12
Total number of tree credits
35
Total number of viable tree creds
31
Total number of required tree credits (35*.3)
11
Total number of retained tree credits
19
Mitigation
26
I have included a detailed report of my findings. If you have any questions, please call me. I can be
reached on my cell phone: 425.890.3808 or by email: sprince202@aol.com.
Warm regards,
Susan Prince
Creative Landscape Solutions
ISA Certified Arborist: PN #1418A
TRACE Certified Arborist: #418
17518 NE 119th Way
Redmond, WA 98052
* Per City of Edmonds 23.10.020(P) Significant Tree - A tree that is at least six (6) inches in diameter at breast
height (DBH) as measured at 4.5 feet from the ground. For trees with multiple leaders at four and one-half (4.5)
feet height, the DBH shall be the combined cumulative total of branches greater than six (6) inches diameter at
four and one-half (4.5) feet above the average grade. If a tree has been removed and only the stump remains that
is below four and one-half (4.5) feet tall, the size of the tree shall be the diameter of the top of the stump.
Creative Landscape Solutions 2
7918 203rd St SW
Personal qualifications, scope of work and methodology
My examination was limited to a visual one, and did not involve any root excavation, trunk
or limb coring, or any soil testing. 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 worked in the
field of arboriculture since 1996, have been an ISA Certified Arborist for since 1999, and
have been TRACE/TRAQ certified since 2009.
I followed protocol delineated by the International Society of Arboriculture (ISA) for Tree
Risk Assessment (TRA). 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, insect, and
disease process) as well as site conditions (soil moisture and composition, the quantity 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). 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.
Each species and variety of tree grows 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
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 tend 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.
Creative Landscape Solutions 3
7918 203rd St SW
Methods 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 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. Tree
diameters were measured at DSH (diameter standard height - 4.5' above ground) using a
logger's tape. Tree driplines were measured using a PRO Laser RangefinderTM.
Spreadsheet Legend:
1. Tree tag #: Numbered aluminum tags attached to the trees in the field*'
2. Species: The Latin and common name five a tree
Species: 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: Corpus nuttallii
• 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
• Nobel fir: Abies procera
• 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 fir: Abies concolor
• White pine: Pinus strobus4. DBH: Diameter of the tree measured at 42" above grade
5. Adjusted Diameter of the tree: Calculated equivalent for multi -stemmed tree
6. Dripline Radius: Measurement in feet of the tree canopy from tree trunk to outermost branch tip
7.A. Windfirm: Whether the tree as a single retained tree has the trunk taper and buttress roots to
enable it to withstand strong gusts of
7.B. OK in Grove: the tree might not be windfirm as a stand-alone tree, however, it might be able to
be retained if it is located within a retained grove of 3+ trees with touching canopies.
8. 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
Creative Landscape Solutions 4
7918 203rd St SW
• Excellent: Tree is an ideal specimen for the species with no obvious flaws
• Good: Tree has minimal structural or situational defects
• OK: Tree has minimal structural defects AND minimal environmental concerns
• 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.
9. Defects/Concerns: A measure of the tree's structural stability and failure potential and rated as
good, fair or poor 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.
10. Proposed action:
• Retain
• Remove due to viability
• Remove due to planned development (tree is otherwise healthy)
11. Limits of disturbance: The area surrounding the tree that defines the area that surrounds the
trunk that cannot be encroached upon during construction. This may be a multiple of the trunk
diameter (1 -1.5 times the trunk diameter converted to feet.) or it may be related to the width
of the canopy. It is always determined by tree species and environment and is up to the
discretion of the ISA Certified Arborist to determine.
12. Tree Value: The measure of the tree by the municipality. Value maybe determined by the tree
SBH or it may be based on a table of corresponding tree credits, or it may be a % of the
number of trees on site.
Creative Landscape Solutions
7918 203rd St SW
Specific Offsite Tree Observations:
1
2
3
4
5
6
7
8
9
10
11
12
13
Proposed
Action
CRZ/TPZ/LOD
Retain
Remove
Radius in feet
m
Drip-
v
L_
_
#
Tree
TagDBH
Species
DBH
AdI'
line
Wind-
OK in
Health
Defects/Comments
m
a) *'
v
v
~
T
_0
a)
n3
#
ID
(in)
in
radius
firm
Grove
N
=
0)
N
W
E
S
=
a)0
c
o o
i
z
0
z
E
1
577
Douglas
fir
14
14
14
OK
Typical of species
1
14
14
14
14
1
1
2
2
578
Douglas
12
12
12
OK
Co -dominant canopy,
1
12
12
12
12
1
1
2
fir
typical of species
Asymmetric canopy towards
3
579
Madrona
6
6
9
OK
east, lean towards east,
1
9
9
9
9
1
1
1
typical of species
Lean towards east,
4
581
Madrona
8
8
12
OK
asymmetric canopy towards
1
12
12
12
12
1
1
1
east, typical of species
Bigleaf
Dead top, asymmetric
5
582
maple
10
10
8
Poor
canopy towards east, dead
1
8
8
8
8
1
wood, broken branches
Calloused wound @ 10,
6
583
Elm
10
10
15
Fair
towards west, lean towards
1
15
15
15
15
1
1
1
west, typical of species
Western
7
584
red
32
32
21
OK
Typical of species
1
21
21
21
21
1
1
3
cedar
Western
Thin canopy, asymmetric
8
585
red
17
17
12
OK
canopy towards east,
1
12
12
12
12
1
1
1
cedar
typical of species
Western
9
586
red
9
9
9
OK
Typical of species
1
9
9
9
9
1
1
1
cedar
Creative Landscape Solutions
7918 203rd St SW
1
2
3
4
5
6
7
8
9
10
11
12
13
Proposed
Action
CRZ/TPZ/LOD
Retain
Remove
Radius in feet
m
v
Tree
Add'
Drip-
v
cu
;v
~
_
#
TagDBH
Species
DBH
line
Wind-
OK in
Health
Defects Comments
'0
#
ID
(in)
in
radius
firm
Grove
N Q)
H
S
vM
N
W
E
S
=
c
0 o
1 L
0
Z
0
Z
Douglas
Thin canopy, previous top
10
587
fir
31
31
16
OK
loss, elongated branches,
1
16
16
16
16
1
1
1
typical of species
Suppressed canopy,
11
588
Douglas
8
8
8
OK
asymmetric canopy towards
1
8
8
8
8
1
1
1
fir
west, free flowing sap,
typical of species
Douglas
Asymmetric canopy towards
12
589
fir
22
22
14
OK
south, free flowing sap,
1
14
14
14
14
1
1
1
typical of species
Asymmetric canopy towards
13
590
Douglas
20
20
15
Fair
south, low live crown ratio
1
15
15
15
15
1
1
1
fir
<30%, exposed roots,
typical of species
Low live crown ratio <20%,
Douglas
horizontal crack @ 50'
14
591
fir
19
19
12
Fair
towards east, typical of
1
12
12
12
12
1
1
1
species, bulge @ 4' towards
north
Western
Co -dominant leaders with
15
592
red
14
14
14
Fair
included bark x2 @ 10',
1
14
14
14
14
1
1
1
cedar
hanger, typical of species
Bigleaf
Moss and lichen, previous
16
701
maple
36
36
22
Poor
scaffold lost @ 40' towards
1
22
22
22
22
1
east
Douglas
Asymmetric canopy towards
17
702
fir
23
23
16
OK
south, dead wood, broken
1
16
16
16
16
1
1
1
branches, typical of species
Creative Landscape Solutions
7918 203rd St SW
1
2
3
4
5
6
7
8
9
10
11
12
13
Proposed
Action
CRZ/TPZ/LOD
Retain
Remove
Radius in feet
Tree
Add'
Drip-
~
v
#
TagDBH
Species
DBH
line
Wind-
OK in
Health
Defects/Comments
a
#
ID
(in)
(in)
)
radius
firm
Grove
(ft)
ra
>
r
>
E
> v
N
W
E
S
j
c
c
o >
o
=
a
z
z°
Q) CI
Low live crown ratio <30%,
18
703
Douglas
13
13
14
OK
asymmetric canopy towards
1
14
14
14
14
1
1
1
fir
southwest, typical of
species
Douglas
Previous top loss, elongated
19
704
fir
24
24
16
OK
branches, thin canopy,
1
16
16
16
16
1
1
1
typical of species
Western
Calloused wound @ 4'
20
705
red
16
16
14
OK
towards north, thin canopy,
1
14
14
14
14
1
1
1
cedar
typical of species
21
706
Western
red
10
10
8
OK
Suppressed canopy, typical
1
8
8
8
8
1
1
1
cedar
of species
Western
Thin canopy, asymmetric
22
707
red
25
25
12
OK
canopy towards south,
1
12
12
12
12
1
1
1
cedar
typical of species
Douglas
Previous top loss, elongated
23
708
fir
16
16
18
Fair
branches, weak laterals,
1
18
18
18
18
1
1
1
exposed roots
24
709
Western
red
10
10
14
OK
Co -dominant canopy, thin
1
14
14
14
14
1
1
1
cedar
canopy, typical of species
Girdling roots, cavity @ root
25
710
Bigleaf
32
32
22
OK
crown, co -dominant leaders
1
22
22
22
22
1
1
1
maple
with included bark x2 @
25', strong leaders
Western
Column of decay @ root
26
711
red
22
22
14
OK
crown up to 8' towards
1
14
14
14
14
1
1
1
cedar
northeast, thin canopy,
typical of species
Creative Landscape Solutions
7918 203rd St SW
1
2
3
4
5
6
7
8
9
10
11
12
13
Proposed
Action
CRZ/TPZ/LOD
Retain
Remove
Radius in feet
m
v
Tree
Add'
Drip-
v
cu
~
C:
o
#
TagDBH
Species
DBH
line
Wind-
OK in
Health
Defects/Comments
m
v
#
ID
(in)
in
radius
firm
Grove
Z
:E
N Q)
H
S
v)
N
W
E
S
=
0 o
L
0
Z
0
Z
Western
27
712
red
6
6
8
OK
Typical of species
1
8
8
8
8
1
1
1
cedar
Douglas
Typical of species,
28
713
fir
14
14
12
OK
asymmetric canopy towards
1
12
12
12
12
1
1
2
west
29
714
Douglas
24
24
18
OK
Typical of species
1
18
18
18
18
1
1
3
Self -corrected lean towards
Douglas
north, asymmetric canopy
30
715
fir
16
16
16
OK
towards north, dead wood,
1
16
16
16
16
1
1
2
broken branches, dead
twigs, typical of species
Western
31
716
red
21
21
15
OK
Typical of species
1
15
15
15
15
1
1
3
cedar
Western
Topped @ 12', strong
32
717
red
16
16
14
OK
leader, typical of species
1
14
14
14
14
1
1
3
cedar
Western
33
718
red
18
18
16
OK
Typical of species
1
16
16
16
16
1
1
3
cedar
34
719
Bitter
cherry
10
10
18
Poor
Failing towards northwest
1
18
18
18
18
1
Moss and lichen, dead
Norway
wood, broken branches,
35
720
maple
14
14
10
Poor
cavity @ root crown up to 2'
1
10
10
10
10
1
towards south, horizontal
crack @ 5' towards south
35 19 0 4 12 35 31 19 26
Creative Landscape Solutions
7918 203rd St SW
Offske Trees:
1
2
3
4
5
6
7
8
9
10
11
Proposed
CRZ/TPZ/LOD
Action
Retain
Radius in feet
Tree
Add'
Drip-
#
Tag
Species
DBH
DBH
line
Wind-
OK in
Health
Defects/Comments
#
ID
inches
inches
radius
firm
Grove
0
feet
5
N
W
E
S
c
0
z
1
A
pinlee
20
20
20
OK
Typical of species
1
20
20
20
20
2
B
Douglas
18
18
15
OK
Previous top loss, coning,
1
15
15
15
15
fir
typical of species
6
Previous top loss,
3
C
Hemlock
14
14
over
Poor
asymmetric canopy towards
1
6
6
6
6
fence
west
Western
15
4
D
red
20
20
over
OK
Typical of species
1
15
15
15
15
cedar
fence
Douglas
12
5
E
fir
22
22
over
OK
Typical of species
1
12
12
12
12
fence
Creative Landscape Solutions 10
7918 203rd St SW
Aerial View:
Creative Landscape Solutions 11
7918 203rd St SW
Proposed Site Improvements: (For reference only; See Civil plans for specifics)
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Creative Landscape Solutions 12
7918 203rd St SW
Discussion/Calculations/Conclusion:
Tree Density Calculations
Total number of onsite trees
35
Total number of non -viable trees
4
Total number of viable trees
31
Total number of trees removed for site improvements
12
Total number of tree credits
35
Total number of viable tree creds
31
Total number of required tree credits (35*.3)
11
Total number of retained tree credits
19
Mitigation
26
The .51-acre site has thirty-five (35) onsite trees. The applicant proposes to divide the site into two
(2) single family residential (SFR) lots. The south side of the property is a dedicated tree retention
area.
Of the thirty-five (35) site trees, four (4) of the trees are considered non -viable or not suitable for
retention due to structural, health, or soil conditions. Thirty-one (31) trees are viable. The Edmonds
Municipal Code (EMC 23.10.060. C.1) requires that 30% of the significant onsite trees be retained (35
* .3 = 11). The proposed site improvements retain nineteen (19) significant trees, exceeding the tree
density code by eight (8) trees. Because the proposed site improvements include a 50% tree retention
no fee in lieu of is required.
Mitigation for removed viable trees is twenty-six (26) trees.
Specific responses to RFI: (responses are highlighted in yellow)
Trees: The following comments are based on compliance with tree Ordinance No. 4227:
a. Additional Tree Retention: The arborist report notes that utility lines will be installed
within the driplines of trees 577 - 584 and so they are proposed to be removed from the
eastern property line area. Tree 582 is in poor health, but the others are OK or Fair. Could the
healthy trees be retained by shifting the utility easement slightly to the west and/or avoiding
trenching within the driplines? In any event, the proposed work appears to be nearly outside
or just inside the critical root zone of tree 584. This idea was considered and rejected by RAM
Engineering and me, there is not enough space between the proposed home and the property
line to make a difference in tree retention. The trees will be shown to be removed.
At the same time, trees 701 and 708 are shown to be removed from within the proposed tree
protection area. While they are described as being in Poor health, they should be retained
unless they pose a hazard. Please provide additional justification for removing these two trees.
Tree # 708 is now shown to be retained, it does not present a high risk to the area, however,
tree # 701 was considered to be at high risk of failure by both Tom Hanson (ISA Certified
arborist) and myself. It can be cut to habitat height, but it cannot be retained as is filled with
advanced decay.
b. Off -site trees: Tree C is off -site but proposed to be removed; provide confirmation that
the tree's owner approves of the proposed removal. Trees A, B, D, and E would also appear to
be impacted by proposed construction of utility lines or paving within their critical root zones.
The City strongly encourages you to contact those neighbors about the proposed development
and potential impacts to those boundary trees. Tree "C" was unintentionally shown to be
Creative Landscape Solutions 13
7918 203rd St SW
removed, I have revised the headings column of the offsite trees to show that the tree is not
viable, however, it is not shown to be removed.
C. Appraisals for tree 24 DBH and larger: For each significant tree with a 24-inch DBH
that will be removed, a fee based on an appraisal of the tree value using the trunk formula
method of the Guide for Plant Appraisal is required per ECDC 23.10.080.E.3. There are three
of these trees (584, 701, and 714). If they are still proposed to be removed (see Comment A
for tree 584 and 701), please provide tree appraisals for these trees. Information provided by
Tom Hanson.
d. Replacement: ECDC 23.10.080.13.1 notes that no replacement is required for trees
that are hazardous, dead, diseased, injured, or in a declining condition with no reasonable
assurance of regaining vigor (trees in Poor health fall into this category and do not require
replacement). At the same time, removal of trees with a 24-inch DBH or larger do not require
replacement trees since a fee based on their value is required to be paid into the tree fund if
they are removed (if tree 584 is still to be removed - see Comment A).
The arborist report submitted with the current application changed several trees (701, 708,
and 720) from Fair health to Poor compared to the previous report submitted with the
withdrawn application under file number PLN2021-0023. The condition of the tree was not
changed, rather it was noted that the change was made "to better comply with the verbiage of
the City of Edmonds Tree Protection Code." Fair is one of the general health conditions
referenced in ECDC 23.10.060.B.2.iv. It is uncertain why trees 701 and 708 were changed
since they are in grove marked for retention (see Comment A). Please clarify. Tree # 708 is
now shown to be retained. Advanced decay was found by Tom Hanson (ISA Certified arborist)
confirming the decay in the dead scaffold continued into the trunk and put it at high risk of
failure.
e. Fee -in -lieu: Since more than 50% of the significant trees on the site are being
retained (18 out of 35), a fee -in -lieu is not required per ECDC 23.10.060.G. Noted.
f. Replacement tree plan: The preliminary submittal did not include a plan showing
where replacement trees required by ECDC 23.10.080.A are proposed to be planted. This can
either be provided during civil review or with building permits if a phased review is used. This
will be shown during the building permit phase, applicant is submitting a phased review.
Mitigations: Per ECDC 23.10.080.A (1-3)
A. Replacement required. Tree replacement is required for tree cutting permits required by this
chapter and/or for tree removal associated with the development types identified in ECDC
23.10.060.A. Each significant tree to be removed shall be replaced as follows:
1. For each significant tree between 6 inches and 10 inches DBH removed, one (1)
replacement tree is required.
2. For each significant tree between 10.1 inches and 14 inches in DBH removed, two (2)
replacement trees are required.
3. For each significant tree greater than 14 inches in DBH removed, three (3) replacement
trees are required.
Replacement Specifications:
1. Minimum sizes for replacement trees shall be:
a. one -and -one -half -inch caliper for deciduous trees;
b. Six feet in height for evergreen trees.
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2. The director may consider smaller -sized replacement trees if the applicant can demonstrate that
smaller trees are more suited to the species, the site conditions, and the purposes of this section,
and that such trees will be planted in sufficient quantities to meet the intent of this section.
3. Replacement trees shall be primarily native species.
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Tree Protection Fencing: Tree Protection fencing should be erected prior to any site grading
First, protect roots that lie in the path of construction. Approximately 90 to 95 percent of a tree's root
system is in the top three feet of soil, and more than half is in the top one foot. Construction activities
should be avoided in this area. Protect as much of the area beyond the tree's dripline as possible.
Some healthy trees survive after losing half of their roots. However, other species are extremely
sensitive to root damage even outside the dripline.
Do not disturb the Critical Root Zone (CRZ). The CRZ is defined by its "critical root radius." Cde
requirements vary. In some municipalities the CRZ is the trees dripline, in other cities it is a function
of the DBH. To calculate critical root radius, measure the tree's diameter (DBH) in inches, 4.5 feet
above the ground. For each inch, allow for 1 to 1.5 feet of critical root radius. If a tree's DBH is ten
inches, its critical root radius is 10 to 15 feet. In practical field work, the arborist may extend or
reduce the trees CRZ measure based on site growing conditions, tree species, and tree shape for
example having an asymmetric canopy.
In addition to the CRZ, it is important to determine the Limits of Disturbance (LOD) for preserved
trees. Generally, this approximates the CRZ however in previously excavated areas around the dripline
the LOD may be smaller, or in the case of a tree situated on a slope the LOD may be larger. The
determination of LOD is also subject to the tree species. Some tree species do better than others after
root disturbance.
Tree protection is advised throughout the duration of any construction activities whenever the critical
root zone or leaf canopy many be encroached upon by such activities.
The Critical Root Zone (CRZ) or LOD should be protected with fencing adequate to hinder access to
people vehicles and equipment. Fencing detail is provided. It should consist of continuous 4 ft. high
temporary chain -link fencing with posts sec at 10' on center or polyethylene laminar safety fencing or
similar. The fencing must contain fencing signage detailing that the tree protection area cannot be
trespassed on.
Soil compaction is one of the most common killers of urban trees. Stockpiled materials, heavy
machinery and excessive foot traffic damage soil structure and reduce soil pore space. The effected
tree roots suffocate. When construction takes place close to the protected CRZ, cover the site with 4
inches of bark to reduce soil compaction
Tree Protection fencing must be erected prior to soil excavation, boring, grading or fill operations. It
is erected at the LOD. If it is necessary to run utilities within the LOD, the utilities should be combined
into one cut, as practical. Trenching is not allowed in the LOD. In these areas, boring or tunneling
techniques should be used. If roots greater than 1" diameter near the LOD are damaged or torn, it is
necessary to hand trim them to a clean cut. Any roots that are exposed during construction should be
covered with soil as soon as possible.
During drought conditions, trees must be adequately watered. Site should be visited regularly by a
qualified ISA Certified Arborist to ensure the health of the trees. Tree protection fencing is the last
item to be removed from the site after construction is completed.
After construction, has been completed, evaluate the remaining trees. Look for signs and symptoms of
damage or stress. It may take several years for severe problems to appear.
If fencing around portions of the CRZ of a tree to be retained are not practical to erect due to
construction or obstacles, tree protection fencing should be placed three feet laterally from the
obstruction (ex. three feet back of a curb, building, or other existing or planned permanent
infrastructure.
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Glossary:
ANSI A300: American National Standards Institute (ANSI) standards for tree care
Chlorotic: discoloration caused by lack of chlorophyll in the foliage
Conifer: A tree that bears cones and has evergreen needles or scales
Crown: the above ground portion of the tree comprised of branches and their foliage
Crown raise pruning: a pruning technique where the lower branches are removed, thus
raising the overall height of the crown from the ground
DBH or DSH: diameter at breast or standard height; the diameter of the trunk measured 54
inches (4.5 feet) above grade
Deciduous: tree or other plant that loses its leaves annually and remains leafless generally
during the cold season
Epicormic: arising from latent or adventitious buds
Evergreen: tree or plant that keeps its needles or leaves year-round; this means for more
than one growing season
Increment: the amount of new wood fiber added to a tree in a given period, normally one
yea r.
ISA: International Society of Arboriculture
Landscape function: the environmental, aesthetic, or architectural functions that a plant can
have
Lateral: secondary or subordinate branch
Limits of disturbance: The boundary of minimum protection around a tree, the area that
cannot be encroached upon without possible permanent damage to the tree. It is a
distance determined by a qualified professional and is based on the age of the tree,
its health, the tree species tolerance to disruption and the type of disturbance. It
also considers soil and environmental condition and previous impacts. It is unique to
each tree in its location.
Limited visual assessment: a visual assessment from a specified perspective such as foot,
vehicle, or aerial (airborne) patrol of an individual tree or a population of trees near
specified targets to identify specified conditions or obvious defects (ISA 2013)
Live crown ratio: the percentage of living tissue in the canopy versus the tree's height. It is
a good indicator of overall tree health and the trees growing conditions. Trees with
less than a 30% Crown ratio often lack the necessary quantity of photosynthetic
material necessary to sustain the roots; consequently, the tree may exhibit low vigor
and poor health.
Monitoring: keeping a close watch; performing regular checks or inspections
Owner/manager: the person or entity responsible for tree management or the controlling
authority that regulates tree management
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Pathogen: causal agent of disease
Phototropic growth: growth toward light source or stimulant
ROW: Right-of-way; generally referring to a tree that is located offsite on a city easement
Reaction wood: Specialized secondary xylem which develops in response to a lean or similar
mechanical stress, it serves to help restore the stem to a vertical position
Self -corrected lean: a tree whose trunk is at an angle to the grade but whose trunk and
canopy changes to become upright/vertical
Significant tree: a tree measuring a specific diameter determined by the municipality the
tree grows in. Some municipalities deem that only healthy trees can be significant,
other municipalities consider both healthy and unhealthy trees of a determined
diameter to be significant
Snag: a tree left partially standing for the primary purpose of providing habitat for wildlife
Soil structure: the size of particles and their arrangement; considers the soil, water, and air
space
Sounding: process of striking a tree with a mallet or other appropriate tool and listening for
tones that indicate dead bark, a thin layer of wood outside a cavity, or cracks in
wood
Structural defects: flaws, decay, or other faults in the trunk, branches, or root collar of a
tree, which may lead to failure; may be genetic, or environmental
Tree credit: A number assigned to a tree by a municipality that may be equal to the
diameter of the tree or a numerical count of the tree, or related to diameter by a
factor conveyed in a table of the municipal code
Trunk area: the cross -sectional area of the trunk based upon measurement at 54 inches
(4.5 ft.) above grade
Visual Tree Assessment (VTA): method of evaluating structural defects and stability in trees
by noting the pattern of growth. Developed by Claus Mattheck (Harris, et al 1999)
detailed visual inspection of a tree and surrounding site that may include the use of
simple tools. It requires that a tree risk assessor walk completely around the tree
trunk looking at the site, aboveground roots, trunk, and branches (ISA 2013)
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References
Dirr, Michael A. Manual of Woody Landscape Plants, Their Identification, Ornamental
Characteristics, Culture, Propagation, and Uses. Champaign: Stipes Publishing
Company, 1990.
Dunster & Associates Environmental Consultants Ltd. Assessing Trees in Urban Areas and
the Urban -Rural Interface. US Release 1.0. Silverton: Pacific Northwest Chapter ISA,
2006.
Dunster, J. A. 2003. Preliminary Species Profiles for Tree Failure Assessment. Bowen Island:
Dunster & Associates Environmental Consultants Ltd.
Dunster, Julian A., E. Thomas Smiley, Nelda Matheny and Sharon Lilly. Tree Risk
Assessment Manual. Champaign, Illinois: International Society of Arboriculture,
2013.
Harris, Richard W, James Clark, and Nelda Matheny. Arboriculture, Integrated Management
of Landscape Trees, Shrubs, and Vines. 4th ed. Upper Saddle River: Prentice Hall,
2004.
Lilly, Sharon. Arborists' Certification Study Guide. Champaign, IL: The International Society
of Arboriculture, 2001.
Matheny, Nelda and Clark, James R. A Photographic Guide to the Evaluation of
Hazard Trees in Urban Areas. Second Edition. Champaign, IL: The International
Society of Arboriculture, 1994.
Matheny, Nelda and Clark, James R. Trees and Development: A Technical Guide to
Preservation of Trees During Land Development. Champaign, IL: The
International Society of Arboriculture, 1998.
Mattheck, Claus and Breloer, Helge. The Body Language of Trees: A Handbook for Failure
Analysis. London: HMSO, 1994
Schwarze, Francis W.M.R. Diagnosis and Prognosis of the Development of Wood Decay in
Urban Trees. Australia: ENSPEC Pty Ltd. 2008
Sinclair, Wayne A., Lyon, Howard H., and Johnson, Warren T. Diseases of Trees and Shrubs.
Ithaca, New York: Cornell University Press, 1987.
Smiley, E. Thomas, Nelda Matheny, and Sharon Lilly, Tree Risk Assessment Best
Management Practices, ANSI A300 Part 9: Tree, Shrub, and Other Woody Plant
Management —Standard Practices (Tree Risk Assessment: Tree Structure
Assessment). The International Society of Arboriculture Press. Champaign. IL. 2011.
Thies, Walter G. and Sturrock, Rona N. Laminated root rot in Western North American.
United States Department of Agriculture. Pacific Northwest. Resource Bulletin PNW-
GTR-349. April 1995.
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Assumptions and Limiting Conditions
1. Any legal description provided to the consultant/appraiser is assumed to be correct. Any titles
and ownerships to any property are assumed to be good and marketable. No responsibility is
assumed for matters legal in character. Any and all property is appraised or evaluated as thou
free and clear, under responsible ownership and competent management.
2. It is assumed that any property is not in violation of any applicable codes, ordinances, statutes
or other governmental regulations.
3. Care has been taken to obtain all information from reliable sources. All data has been verified
insofar as possible; however, the consultant/appraiser can neither guarantee nor be
responsible for the accuracy of information provided by others.
4. The consultant/appraiser shall not be required to give testimony or to attend court by reason
of the report unless subsequent contractual arrangements are made including payment of an
additional fee for such services as described in the fee schedule and contract of engagement.
5. Loss or alteration of any part of this report invalidates the entire report.
6. Possession of this report or a copy thereof does not imply right of publication or use for any
purpose by any other than the person to whom it is addressed, without the prior expressed
written or verbal consent of the consultant/appraiser.
7. Neither all nor any part of the contents of the report, nor copy thereof, shall be conveyed by
anyone, including the client to the public through advertising, public relations, news, sales or
other media, without the prior expressed written or verbal consent of the consultant/appraiser
- particularly as to value conclusions, identity of the consultant/appraiser, or any reference to
any professional society or instate or to any initialed designation conferred upon the
consultant/appraiser as stated in her qualification.
8. The report and any values expressed herein represent the opinion of the consultant/appraiser,
and the consultant's/appraiser's fee is in no way contingent upon the reporting of a specified
value, a stipulated result, the occurrence of subsequent event, nor upon any finding to be
reported.
9. Sketches, diagrams, graphs and photographs in this report, being intended as visual aid, are
not necessarily to scale and should not be construed as engineering or architectural reports or
survey.
10. Unless expressed otherwise: 1) information contained in this report covers only those items
that were examined and reflects the condition of those items at the time of inspection; and 2:
the inspection is limited to visual examination of accessible items without dissection,
excavation, probing or coring. There is not warranty or guarantee, expressed or implied, that
problems or deficiencies of the plants or property in question may not arise in the future.