HomeMy WebLinkAboutArborist Report
Protected Tree Report:
Tree Survey, Encroachment,
Protection and Mitigation
758 Hampton Road
Arcadia, CA 91006
Prepared For: Mr. Tony Tang
(626) 353-8686
chaoyintang@yahoo.com.tw
Prepared By: Michael Crane
Arbor Care, Inc.
P.O. Box 51122
Pasadena, CA 91115
Tel: (626) 737-4007
Fax: (626) 737-4007
Email: info@arborcareinc.net
February 2017
Revised March 2018, July 2018
Table of Contents
Summary of Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Background and Purpose of Report . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Project Location, Description & Tree Ordinance . . . . . . . . . . . . . . . . . . . . . . . . 2
Observations & Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Tree Characteristics & Health Matrix . . . . . . . . . . . . . . . . . . . . . 8
Construction Impact Matrix . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Findings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Further Recommendations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Appendix A - Photos . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Appendix B - Protected Tree Construction Impact Guidelines . . . . . . . . . . . . . . 19
Author’s Certifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Certification of Performance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Topographical Conceptual Site Plan . . . . . . . . . . . . . . . . . . . . . . . . . Pocket at back
Protected Tree Report: Survey, Encroachment and Protection Plan
758 Hampton Rd., Arcadia, 91006
Michael Crane, RCA #440. July 2018
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SUMMARY OF DATA
BACKGROUND & PURPOSE
I was retained by the Project Designer and Manager, Mr. Tony Tang, Inc. to be the consulting
arborist for the planned redevelopment of the property located at 758 Hampton Rd. There are
Protected Trees located on the property, and encroaching over the property from off-site. The
proposed construction may impact these trees and this report will serve to both notify the City of
Arcadia Planning Division of the extent of the potential impacts as well as to inform the builder
of the proper protection measures which must be taken in order to preserve the trees. As part of
my preparation for this report I made a site visit to the property on January 31, 2017. I met with
Mr. Tang at that time to view and discuss the proposed construction plans as they relate to the
preservation of the Protected Trees. I was given a conceptual site plan for my analysis.
Revisions to the report were made in March 2018 and again in July 2018 to address the
protection status of Tree #14 and the hazard rating of Tree #5.
Total number of healthy Protected Trees on property including street trees
located in the adjacent public right-of-way area . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Total number of off-site Protected Oak and Sycamore Trees
with canopies (driplines) encroaching onto the property . . . . . . . . . . . . . . . . . . . . 1
Total number of diseased/hazardous Protected Trees on site
proposed for removal (Tree #5) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Total number of healthy Protected Trees to be preserved . . . . . . . . . . . . . . . . . . . 10
Total number of healthy Protected Trees to be removed . . . . . . . . . . . . . . . . . . . 2
Total number of Protected Trees that will be preserved, which will
be impacted by construction within dripline (encroached) . . . . . . . . . . . . . . . . . . 10
Total number of Protected Trees with no dripline encroachments . . . . . . . . . . . 0
Total number of proposed mitigation trees to be planted on site . . . . . . . . . . . . . . 2
Protected Tree Report: Survey, Encroachment and Protection Plan
758 Hampton Rd., Arcadia, 91006
Michael Crane, RCA #440. July 2018
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PROJECT LOCATION, DESCRIPTION & TREE ORDINANCE
758 Hampton Road is easily accessed from N. Baldwin Ave., three blocks north of
W. Foothill Blvd. The property is one half block west of N. Baldwin. Above map
courtesy of Apple Maps.
The property consists of a one story single-family residence that appears to be in fair condition.
The home will be demolished and the property redeveloped into a two story single family home.
N
Protected Tree Report: Survey, Encroachment and Protection Plan
758 Hampton Rd., Arcadia, 91006
Michael Crane, RCA #440. July 2018
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The landscape is maintained and the woody plants and trees are in fair to good condition. The
Protected Trees range in condition from poor to good. The landscape will be renovated and
most of the Protected Trees will be incorporated into the new design.
2
N
1
3
4
6
5
7 8
9
10
11
12 13
14
Protected Tree Report: Survey, Encroachment and Protection Plan
758 Hampton Rd., Arcadia, 91006
Michael Crane, RCA #440. July 2018
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This aerial view (courtesy of Apple Maps) has been illustrated to show the
approximate boundary lines (orange). The locations of the Protected Trees are
numbered in yellow.
City of Arcadia Tree Ordinance
Oaks, Sycamore, and many other tree species are Protected under the various tree
ordinances. Here is a summary of the tree protection laws.
On January 21, 1992 the City Council adopted Ordinance No. 1962 recognizing oak trees as significant aesthetic
and ecological resources and establishing criteria for the preservation of oak trees. The regulations (Chapter 7 of
the Arcadia Municipal Code) provide that the following oak trees shall not be removed, relocated, damaged, or
have their protected zones encroached upon unless an Oak Tree Permit is granted:
• Engelmann Oaks (Quercus engelmannii) or Coast Live Oak, California Live Oak (Quercus agrifolia)
which have a trunk diameter larger than four (4) inches measured at a point four and one half (4 ½) feet
above the crown root, or, two (2) or more trunks measuring three (3) inches each or greater in diameter,
measured at a point four and one half (4 ½) feet above the crown root.
• Any other living oak tree with a trunk diameter larger than twelve (12) inches measured at a point four
and one half (4 ½) feet above the crown root, or, two (2) or more trunks measuring ten (10) inches each
or greater in diameter measured at a point four and one half (4 ½) feet above the crown root.
On March 3, 2015, the City Council adopted Ordinance No. 2323 amending the code to add Sycamore trees to the
list of City's Tree Preservation Regulations. The protected trees are Oak and Sycamore trees. Protected Sycamore
trees are defined as:
• Plantanus racemosa (Sycamore) with a trunk diameter larger than six (6) inches measured at a point four
and one-half (4½) feet above the root crown, or two (2) or more trunks measuring four (4) inches each or
greater in diameter, measured at a point four and one-half (4½) feet above the root crown.
On August 2, 2016, The City Council adopted Ordinance No. 2338 to add additional protected trees and unprotected
trees to the City’s tree preservation regulations. In September, the City began protecting mature trees that are located
within a required front, side, street-side, or rear yard setback area that are either larger than 12 inches in diameter or
larger than 10 inches in diameter if there are multiple trunks.
Below is a list of the unprotected trees:
1. Fruit trees
2. Fraxinus uhdei (Shamel Ash)
3. Ficuses – Exception: Ficus macrophylla (Moreton Bay Fig)
4. Eucalyptus
5. Ailanthus altissima (Tree of Heaven)
6. Arecaceae (Palm Tree)
7. Schinus terebinthifolius (Brazilian Pepper)
8. Ceratonia siliqua (Carob)
9. Betula pendula (European White Birch)
10. Grevillea robusta (Silk Oak)
11. Morus (Mulberry)
12. Acer saccharinum (Silver Maple)
13. Cupressus sempervirens (Italian cypress)
14. Populus Fremontii (Western Cottonwood)
Protected Tree Report: Survey, Encroachment and Protection Plan
758 Hampton Rd., Arcadia, 91006
Michael Crane, RCA #440. July 2018
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15. Alnus rhombifolia (White Alder)
16. Populus trichocarpa (Black Cottonwood)
17. Populus ‘Highland’ hybrid
18. Salix lasiolepis (Arroyo Willow)
19. Liquidambars (Sweet Gum)
FIELD OBSERVATIONS & DESIGN ANALYSIS
Refer to Site Plan located in pocket at back of this report, Tree Characteristics and
Health Matrix on page 8, Construction Impacts Matrix on page 10 and Photos in
Appendix A, page 14.
Analysis regarding rootzone impacts are based on the type of impact, e.g, soil compaction,
grading, and excavation; as well as the distance from the trunk that the impacts will occur. It is
commonly accepted among professional arborists that a distance equal to three times a trunks
diameter contains the structural roots responsible for keeping the tree upright. This critical
rootzone area is defined as the root plate. Beyond the root plate the roots typically taper off into
smaller, less significant sizes. These smaller roots are usually two inches in diameter or smaller
and make up the rootmass responsible for water and nutrient uptake. Although roots of these
sizes can be cut without significantly impacting health and stability it is advised that no more
than 30 percent of the rootmass within the dripline is severed. The bulk of the rootmass is
located within the top three feet of soil and root growth slows or halts when soil bulk density
exceeds 1.60 g/cm3 for most soils. More information regarding rootzone impacts is provided in
the Excavation and Root Pruning section of the Construction Impact Guidelines, Appendix B.
Tree #1 – 26” Coast Live Oak: The tree is located off-site on the property to the east. It is
located in the public right-of-way setback and the trunk is approximately three feet from the east
property line. It is assumed that the existing garden wall located on the property line will
remain. No construction related encroachments will occur. Typical landscape renovations will
encroach. No pruning of the live crown is required to complete the project.
Tree #2 – 24” Chinese Elm: This tree is located in the front yard. No construction related
encroachments will occur. Typical landscape renovations will encroach. No pruning of the live
crown is required to complete the project.
Tree #3 – 18” Aleppo Pine: This tree is located within a couple feet of the east property line in
the front yard. It is assumed that the existing garden wall located on the property line will
remain. No construction related encroachments will occur. Typical landscape renovations will
encroach. No pruning of the live crown is required to complete the project.
Tree #4 – 19” Aleppo Pine: This tree is located in the front yard, within three feet of the east
property line. The foundation for the new house will be built 17 feet from the trunk on its south
side. The assumed five foot overexcavation will come as close as 12 feet and all excavation will
Protected Tree Report: Survey, Encroachment and Protection Plan
758 Hampton Rd., Arcadia, 91006
Michael Crane, RCA #440. July 2018
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be done in the footprint of the existing home. It is assumed that the existing garden wall located
on the property line will remain. No pruning of the live crown is required to complete the
project.
Tree #5 – 13” Carrotwood: This tree is located in the area that will become a side yard. The
foundation for the home will be built within a foot from the trunk and the required
overexcavation will occur where the tree is located. The tree is hazardous and is planned for
removal. The tree is in poor structural condition with several large wounds caused by large
branch failures. Advanced decay is visible in the cavities at the point of failure and the
attachment points of the other branches in the crown are very close to this decay. The resulting
column of decay has made the branch attachments weak and the probability of failure of each
branch is high.
Tree #6 – 14” Carrotwood: This tree is located in the back yard. The foundation for the new
house will be built 16 feet from the trunk on its south side. The assumed five foot
overexcavation will come as close as 11 feet. No pruning of the live crown is required to
complete the project.
Tree #7 – 10” Victorian Box: This tree is located in the southwest corner of the back yard,
within a foot of the south property line. It is assumed that the existing concrete block wall
located on this property line will remain. No construction related encroachments will occur.
Typical landscape renovations will encroach. No pruning of the live crown is required to
complete the project.
Tree #8 – 13” Victorian Box: This tree is located in the southwest corner of the back yard,
within a foot of the south and west property lines. It is assumed that the existing concrete block
wall located on these property lines will remain. No construction related encroachments will
occur. Typical landscape renovations will encroach. No pruning of the live crown is required to
complete the project.
Tree #9 – 10” Victorian Box: This tree is located in the southwest corner of the back yard,
within two feet of the west property line. It is assumed that the existing concrete block wall
located on this property line will remain. No construction related encroachments will occur.
The foundation for the home will be built 20 feet from the trunk and the assumed five-foot
overexcavation will come within 15 feet, just outside the dripline. Typical landscape renovations
will encroach. No pruning of the live crown is required to complete the project.
.
Tree #10 – 14” Victorian Box: This tree is located in the back yard, two feet from the west
property line. The foundation for the new house will be built 13 feet from the trunk on its south
side. The assumed five foot overexcavation will come as close as 8 feet. It is assumed that the
Protected Tree Report: Survey, Encroachment and Protection Plan
758 Hampton Rd., Arcadia, 91006
Michael Crane, RCA #440. July 2018
7
existing concrete block wall located on this property line will remain. Typical landscape
renovations will encroach. Some minor crown raising and reduction type pruning will be
required to accommodate the roofline and exterior walls.
Tree #11 – 12” Carrotwood: This tree is located in the back yard, seven feet from the west
property line. The foundation for the new house will be built 7 feet from the trunk on its south
side. An assumed five foot overexcavation will come as close as 2 feet, which may impact the
tree’s stability. If the overexcavation is not reduced by the soil engineer to three feet or less, than
the foundation shall be constructed with a deeper footing to allow for a further distance from the
trunk. Typical landscape renovations will encroach. Some minor crown raising and reduction
type pruning will be required to accommodate the roofline and exterior walls.
Tree #12 – 13” Chinese Elm: This tree is located in the area that will become the side yard.
The foundation for the home will be built within two feet of the trunk, and overexcavation will
occur where the tree is located. It will be removed. It has structural defects that prevent it from
being a candidate for relocation, and the best mitigation is replacing it with a quality nursery-
grown specimen.
Tree #13 – 15” Chinese Elm: This tree is located in the area that will become the side yard.
The foundation for the home will be built within two feet of the trunk, and overexcavation will
occur where the tree is located. It will be removed. It has structural defects that prevent it from
being a candidate for relocation, and the best mitigation is replacing it with a quality nursery-
grown specimen.
Tree #14 – 16” Olive: The tree is located near the east property line in the side yard area. The
existing home’s foundation is located within five feet of the trunk and the proposed home’s
foundation will have a similar setback, but the assumed overexcavation to construct the building
pad may come within a foot of the trunk. This would be a severe encroachment on most all
broadleaf trees but olives are extremely tolerant of root pruning so the encroachment will be
tolerable. The current plans have a planter area designed on center of the tree and this design will
accommodate the tree very well. No changes to the design are required and the protective fence
that will be set for the adjacent pine tree (Tree #4) can easily be extended to incorporate the
olive.
One of the primary reasons that olives are used in landscapes, particularly redesigned ones, is
their tolerance of root pruning. Mature olives are commonly dug from orchards with a rootball
that is just a foot or several inches from the exposed buttress area. This greatly reduces the
overall installation cost and allows for large mature trees to be planted in a new design at a
relatively low cost. Since the subject tree will not be encroached on one side and not brought
through the rigors of a typical transplanting it is very likely that the tree will be unaffected by the
construction.
Protected Tree Report: Survey, Encroachment and Protection Plan
758 Hampton Rd., Arcadia, 91006
Michael Crane, RCA #440. July 2018
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This chart includes all Protected Trees that are either located or encroaching on the property. It provides physical data collected from
field observations. The trees have been surveyed and numbers correspond to the Site Plan included in this report. Tree numbers with
an “os” indicate that the specimen is located off-site and a portion of the canopy extends over the subject property. Trunk diameters
with an asterisk (*) indicate that the tree is a multi-trunked specimen and the measurement is for the largest leader or trunk.
TREE CHARACTERISTICS & HEALTH MATRIX
CHARACTERISTICS HEALTH
SIZE FORM CROWN
CLASS
AGE
CLASS
FOLIAGE
DENSITY
SHOOT
GROWTH
WOUND
DEFENSE
VIGOR
CLASS TREE NUMBER SPECIES TRUNK DIAMETER (INCHES) APPROXIMATE HEIGHT (FEET) AVERAGE SPREAD (FEET) SYMMETRIC ASYMMETRIC DOMINANT CO-DOMINANT SUPPRESED YOUNG MATURE OVERMATURE NORMAL SPARSE DISEASE / INSECT AVERAGE POOR TWIG DIEBACK NORMAL POOR WOOD DECAY GOOD POOR DISEASED/HAZARDOUS 1os Quercus agrifolia 26 45 50
X
X
X
X
X
X
X
2 Ulmus parvifolia 24 40 40 X
X
X
X
X
X
X
3 Pinus halepensis 18 50 30
X
X
X
X
X
X
X
4 Pinus halepensis 19 50 30
X
X
X
X
X
X
X
5 Cupaniopsis anacardioides 13 25 20 X
X
X
X
X
X X
X X
6 Cupaniopsis anacardioides 14 30 20 X
X
X
X
X
X
X
7 Pittosporum undulatum 10* 35 20
X
X
X X
X X X
X
Protected Tree Report: Survey, Encroachment and Protection Plan
758 Hampton Rd., Arcadia, 91006
Michael Crane, RCA #440. July 2018
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TREE CHARACTERISTICS & HEALTH MATRIX (continued)
CHARACTERISTICS HEALTH
SIZE FORM CROWN
CLASS
AGE
CLASS
FOLIAGE
DENSITY
SHOOT
GROWTH
WOUND
DEFENSE
VIGOR
CLASS TREE NUMBER SPECIES TRUNK DIAMETER (INCHES) APPROXIMATE HEIGHT (FEET) AVERAGE SPREAD (FEET) SYMMETRIC ASYMMETRIC DOMINANT CO-DOMINANT SUPPRESED YOUNG MATURE OVERMATURE NORMAL SPARSE DISEASE / INSECT AVERAGE POOR TWIG DIEBACK NORMAL POOR WOOD DECAY GOOD POOR DISEASED/HAZARDOUS 8 Pittosporum undulatum 13 35 20
X
X
X X
X X X
X
9 Pittosporum undulatum 10* 35 20
X
X
X X
X X X
X
10 Pittosporum undulatum 14 35 20
X
X
X X
X X X
X
11 Cupaniopsis anacardioides 12 30 20 X
X
X
X
X
X
X
12 Ulmus parvifolia 13* 35 30
X
X
X
X
X
X
X
13 Ulmus parvifolia 15 35 30
X
X
X
X
X
X
X
14 Olea europea 16 20 20
X
X
X
X
X
X
X
Protected Tree Report: Survey, Encroachment and Protection Plan
758 Hampton Rd., Arcadia, 91006
Michael Crane, RCA #440. July 2018
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This section includes all Protected Trees that are either located or encroaching on the property. It provides data collected from the
analysis of construction plans. The tree has been surveyed and numbers correspond to the Site Plan included in this report. Tree
numbers with an “os” indicate that the specimen is located off-site and a portion of the canopy extends over the subject property.
CONSTRUCTION IMPACTS MATRIX
TREE SPECIES SIZE &
CONDITION ROOTZONE IMPACTS REQUIRED PRUNING OF
LIVE CROWN TREE NUMBER Protected Trees:
• Quercus agrifolia,
engelmannii, and any
other species of
Quercus genus larger
than 12”
• Platanus racemosa
• Any tree located in the
public right-of-way
• All other species 12” or
larger that are not on
the exemption list TRUNK DIAMETER (DBH) CONDITION Sides of tree where excavation (six inches or deeper) will occur Sides where excavation impacts are buffered by existing infrastructure Excavation will remain a distance of at least 10 X DBH from trunk Excavation will remain a distance of at least 5 X DBH from trunk Excavation will remain a distance of at least 3 X DBH from the trunk Removal or Relocation Additional light grading less than 6" deep to occur within dripline Estimated % of total root mass to be removed or severed No Pruning Required Pruning not to exceed 10% Pruning not to exceed 30% Number of cuts larger than 3" in diameter required Diameter of cuts for branch removals 1 Quercus agrifolia 26 Good - W Yes <10 0 N/A
2 Ulmus parvifolia 24 Good - - Yes <10 0 N/A
3 Pinus halepensis 18 Good - - Yes <10 0 N/A
4 Pinus halepensis 19 Good S S Yes <20 0 N/A
5 Cupaniopsis anacardioides 13 Poor All - - - - - - - -
6 Cupaniopsis anacardioides 14 Good N - Yes <10 0 N/A
7 Pittosporum undulatum 10 Fair - - Yes <10 0 N/A
Protected Tree Report: Survey, Encroachment and Protection Plan
758 Hampton Rd., Arcadia, 91006
Michael Crane, RCA #440. July 2018
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CONSTRUCTION IMPACTS MATRIX (continued)
TREE SPECIES SIZE &
CONDITION ROOTZONE IMPACTS REQUIRED PRUNING OF
LIVE CROWN TREE NUMBER Protected Trees:
• Quercus agrifolia,
engelmannii, and any
other species of
Quercus genus larger
than 12”
• Platanus racemosa
• Any tree located in the
public right-of-way
• All other species 12” or
larger that are not on
the exemption list TRUNK DIAMETER (DBH) CONDITION Sides of tree where excavation (six inches or deeper) will occur Sides where excavation impacts are buffered by existing infrastructure Excavation will remain a distance of at least 10 X DBH from trunk Excavation will remain a distance of at least 5 X DBH from trunk Excavation will remain a distance of at least 3 X DBH from the trunk Removal or Relocation Additional light grading less than 6" deep to occur within dripline Estimated % of total root mass to be removed or severed No Pruning Required Pruning not to exceed 10% Pruning not to exceed 30% Number of cuts larger than 3" in diameter required Diameter of cuts for branch removals 8 Pittosporum undulatum 13 Fair - - Yes <10 0 N/A
9 Pittosporum undulatum 10 Fair N - Yes <10 0 N/A
10 Pittosporum undulatum 14 Fair E - Yes <20 0 N/A
11 Cupaniopsis anacardioides 12 Good N N Yes <30 0 N/A
12 Ulmus parvifolia 13 Good All - - - - - - - -
13 Ulmus parvifolia 15 Good All - - - - - - - -
14 Olea europea 15 Good W W Yes <30 0 N/A
Protected Tree Report: Survey, Encroachment and Protection Plan
758 Hampton Rd., Arcadia, 91006
Michael Crane, RCA #440. July 2018
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FINDINGS
• Trees #5, #12 and #13 will be removed. Removals will occur to accommodate the
primary dwelling structure and not any secondary structure or other infrastructure,
e.g., pool house, pool, motor court, or sports court. None of these trees are of
exceptional quality that would justify relocating them to another area on the
property. Tree #5 has extensive decay coupled with poor branch structure and is
hazardous. Replacing each tree with a nursery quality tree would achieve an
adequate mitigation.
• A typical five-foot overexcavation near Tree #11 would impact the health and
stability. An effort should be made to reduce the overexcavation as much as
possible.
• The close excavation near Tree #14 is tolerable. Olives are extremely tolerant of
root pruning.
• All required excavation for the other nine Protected Trees will occur on one side
of each tree and it is at tolerable distances from the trunks of both Protected
Trees; at least a distance equal to five times the trunk diameter.
RECOMMENDATIONS
As with many construction projects, soil compaction is the most preventable impact that
will need to be monitored in order to provide reliable protection and long-term
preservation of the trees. To prevent unnecessary soil compaction a protective fence
must be installed around the Protected Trees before any demolition occurs. The goal is to
enclose the largest possible amount of space underneath the tree so that the heavy
equipment required for demolition and construction can be routed away from root zones.
The recommended fence placements are drawn in dashed lines on the Site Plan of this
report. The main haul route for the demolition phase and into most of the construction
phase shall be the existing driveway.
• Prior to demolition the contractor and consulting arborist shall meet on site to
make sure fences are properly placed and installed and to review the goals for the
tree protection plan. The location of the protective fences are drawn with a
dashed line on the Site Plan included in this report.
• Tree Protection Zone fences shall be at least four feet tall and constructed of chain
link fencing secured on metal posts.
• The fenced protection zones may be altered during construction; however, any
alterations of the fenced protection zones must be approved by the arborist of
record.
Protected Tree Report: Survey, Encroachment and Protection Plan
758 Hampton Rd., Arcadia, 91006
Michael Crane, RCA #440. July 2018
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• Maintain the fences throughout the completion of the project. No staging of
materials or equipment or washing-out is to occur within the fenced protected
zones.
• The removal of existing turfgrass and other vegetation near the Protected Trees
shall be done by hand. No rototilling or other deep cultivation or grading shall
occur within the driplines.
• Refer to the Construction Impact Guidelines in Appendix B for important general
preservation measures concerning the different elements of this project.
Protected Tree Report: Survey, Encroachment and Protection Plan
758 Hampton Rd., Arcadia, 91006
Michael Crane, RCA #440. July 2018
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APPENDIX A – Photos
ABOVE: Looking east at Trees #1 and #2. No construction will encroach.
BELOW: The trunk of Tree #1 is just off-site. The garden wall on the
property line will most likely remain.
1 2
1
Protected Tree Report: Survey, Encroachment and Protection Plan
758 Hampton Rd., Arcadia, 91006
Michael Crane, RCA #440. July 2018
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ABOVE: The trunk of Tree #4 is located several feet from the existing
home. The new house will have a further setback. BELOW: Looking north
along the east property line at Tree #14. The new home will have a similar
setback and the tree will be situated in a planter.
4
14
Protected Tree Report: Survey, Encroachment and Protection Plan
758 Hampton Rd., Arcadia, 91006
Michael Crane, RCA #440. July 2018
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ABOVE: The required overexcavation for the foundation of the house will
occur where Tree #5 is located. It will be removed and replaced. BELOW:
Tree #5 has structural defects resulting from several large branch failures. It
is a high hazard and should be removed.
5
5
Protected Tree Report: Survey, Encroachment and Protection Plan
758 Hampton Rd., Arcadia, 91006
Michael Crane, RCA #440. July 2018
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ABOVE: Tree #6 is located in the back yard. No construction related
encroachments will occur. BELOW: Trees #7-#11 are grouped in the
southwest quadrant of the property. All trees will be preserved.
6
7 8 9 10 11
Protected Tree Report: Survey, Encroachment and Protection Plan
758 Hampton Rd., Arcadia, 91006
Michael Crane, RCA #440. July 2018
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ABOVE and BELOW: The required overexcavation for the foundation of
the new home will occur where Trees #12 and #13 are located. Both will be
removed and replaced. Both trees have structural elements that prevents
them from being good candidate for relocation.
12 13
13 12
Protected Tree Report: Survey, Encroachment and Protection Plan
758 Hampton Rd., Arcadia, 91006
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APPENDIX B - Protected Tree Construction Impact Guidelines
Size and Distribution of Tree Roots – Taken from Arboriculture, Integrated
Management of Landscape Trees Shrubs and Vines. Harris, R.W., Clark, J.W., Matheny
N.P. Prentice Hall 2004.
Roots of most plants, including large trees, grow primarily in the top meter (3 ft) of soil
(see figure below). Most plants concentrate the majority of their small absorbing roots in
the upper 150 mm (6 in.) of soil if the surface is protected by a mulch or forest litter. In
the absence of a protective mulch, exposed bare soil can become so hot near the surface
that roots do not grow in the upper 200 to 250 mm (8 to 10 in.). Under forest and many
landscape situations, however, soil near the surface is most favorable for root growth. In
addition, roots tend to grow at about the same soil depth regardless of the slope of the soil
surface.
Although root growth is greatly influenced by soil conditions, individual roots seem to
have an inherent guidance mechanism. Large roots with vigorous tips usually grow
horizontally. Similar roots lateral to the large roots grow at many angles to the vertical,
and some grow up into the surface soil. However, few roots in a root system actually
grow down.
Protected Tree Report: Survey, Encroachment and Protection Plan
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The importance of soil
Soil supports and anchors tree roots and provides water, minerals and oxygen.
Furthermore, soil is a habitat for soil microorganisms that enhance root function. A soil’s
ability to sustain tree growth is largely determined by its texture, structure (bulk density),
organic matter, water and mineral content, salinity, aeration, and soil-microbe abundance
and diversity.
Soil physical properties
Soil texture – the relative proportion of sand, silt and clay, is important because it affects
water – and nutrient-holding capacity, drainage and aeration (gaseous diffusion). Soil
structure is the arrangement of individual soil particles into clumps (aggregates). The net
result is the formulation of larger voids between the aggregates which serve as channels
for gaseous diffusion, movement of water and root penetration. Unfortunately, soil
aggregates are readily destroyed by activities that compact the soil (increase bulk
density). When this occurs, gaseous exchange, permeability, drainage and root growth
are restricted.
The influence of the organic matter content of soil properties is quiet significant. Its
decomposition by soil organisms releases substances that bind soil particles into larger
granules, which improves both soil aeration, and drainage. In essence, the breakdown of
organic matter improves water – and nutrient-holding capacity and reduces bulk density.
Furthermore, it is the primary source of nitrogen and a major source of nitrogen and a
major source of phosphorus and sulfur. Without organic matter soil organisms could not
survive and most biochemical processes in the soil would cease.
Soil aeration, the movement and the availability of oxygen, is determined by both soil
texture and structure. In general, compacted and finer soils, due to a higher proportion of
small pore spaces (micropores), tend to drain slowly and hold less air than coarser, sandy,
or well-structured find soils. Water retained in the small pores displaces oxygen and
inhibits gaseous diffusion.
The availability of soil water is largely determined by the size of the pore spaces between
the soil particles and the larger aggregates in which water is held. Most of the water in
the larger pore spaces drains readily due to gravitational forces. A relatively thin film of
water, which is readily available to plant roots, remains following drainage. Much of
water held within the smaller pore spaces resists uptake by plant roots because it is held
tightly on the soil surfaces.
Plant roots require an adequate supply of oxygen for development. Injury or dysfunction
results when oxygen availability drops below a critical level. Root respiration is the first
process to be restricted, followed by disruptions in growth, metabolism, nutrient and
water uptake, and photosynthesis. Furthermore, the accumulation of high levels of
carbon dioxide, produced by the roots during respiration can also impair root function.
Reduced soil aeration resulting from soil compaction, flooding, excess irrigation, or
Protected Tree Report: Survey, Encroachment and Protection Plan
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impervious pavement favors the development of crown rot (Phytophthora root disease).
It also inhibits mycorrhizal fungi that enhance water and nutrient uptake and resist root
pathogens.
The forest floor under a canopy in most undeveloped forests and woodland settings is
typically covered by a layer of fallen leaves and other woody debris. It is usually cool,
shady, well-aerated, and relatively moist – conditions that favor normal root growth.
When the natural leaf litter is removed and when a tree’s lower canopy is pruned up to
provide clearance, the absorbing roots in the upper few inches of the soil experience
higher soil temperatures and increased desiccation due to direct exposure to sunlight.
Minimizing the Effects of Construction and Development on Tree Root Systems
Activities that injure roots or adversely affect the root zone should be avoided or kept as
far from the trunk as possible. Design changes or alternative building practices that avoid
or minimize construction-related impacts should be considered and proposed when
applicable.
Soil Compaction
Soils are intentionally compacted under structures, sidewalks, reads, parking areas, and
load-bearing fill to prevent subsidence, and to prevent soil movement on slopes.
Although unintentional, soil within the root zone of trees is often compacted by
unrestricted foot traffic, parking of vehicles, operation of heavy equipment, and during
installation of fill. Compaction destroys the soil’s natural porosity by eliminating much
of the air space contained within it. It leaves the soil hardm impenetrable and largely
unfavorable for root growth. The soil’s natural porosity, which allows for water
movement and storage, gaseous exchange, and root penetration, is greatly reduced.
Consequently, root growth and tree health suffer. Soil compaction is best managed by
preventing it.
Bulk density is used to describe a soil’s porosity, or the amount of space between soil
particles and aggregates. High bulk densities indicate a low percentage of total pore
space.
Pavement
Paving over the root systems of trees is another serious problem because it reduces the
gaseous diffusion and soil moisture. Most paving materials are relatively impervious to
water penetration and typically divert water away from a tree’s root zone. Cracks and
expansion joints do, though, allow for some water infiltration into the soil below. Of
greater concern, is the loss of roots from excavation to achieve the required grade, and
the necessary compaction to prevent subsidence. Once the soil surface is compacted, a
base material is then added and compacted as well. With that done, the surface can then
be paved. Thus, pavement within the root zones of trees can damage roots and create
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unfavorable soil conditions. One alternative to minimize pavement impacts is to consider
placing the pavement on the natural grade over a layer of minimally compacted base
material. To reduce sub-grade compaction, consider using reinforced concrete or asphalt
over a goetextile blanket to help stabilize the soil. On-grade patios or paving that covers
more than one-third of the tree protection zone (TPZ) should be constructed using
permeable materials that allow aeration and water penetration. Soil under permeable
surfaces should not be compacted to more than 80 percent.
Excavation and root pruning
Excavation within the root zones of trees should be avoided as much as possible. The
extent of root pruning (selective) or cutting (non-selective) should be based on the
species growth characteristics and adaptive traits, environmental conditions, age, health,
crown size, density, live crown ration and structural condition of the tree. The timing of
the root pruning or cutting is another important consideration. Moderate to severe root
loss during droughts or particularly hot periods can cause serious water-deficit injury or
death.
When root pruning/ cutting is unavoidable, roots should be pruned or cut as far from the
trunk as possible. Cutting roots on more than one side of a tree should also be avoided.
Root cutting extending more than half-way around a tree should generally be no closer
than about 10 times the trunk diameter. Recommended distances range from as little as 6
times trunk diameter (DBH) for young trees to 12 times trunk diameter for mature trees.
The size of the TPZ should, however, be increased for over mature and declining trees
and species that are sensitive to root loss.
The minimum distance from the trunk that roots can be cut on one side of the tree without
destabilizing it, is a distance equal to about three times the diameter (DBH) of the trunk.
Roots severed within that distance provide little or no structural support. Root pruning or
cutting distances from the trunk should be greater for trees that lean and/ or those
growing on shallow or wet soil.
In cases where the proposed grading will adversely affect trees designated for retention,
special attention should be given to proper root pruning and post-construction care for
injured trees. Where structural footings are required for foundations, retaining walls, etc.,
and roots larger than 2 inches in diameter will be impacted, consider design changes or
alternative building methods.
When excavation within 5 times trunk diameter is unavoidable, roots greater than 1 ½
inches in diameter should be located prior to excavation and then pruned to avoid
unnecessary damage. Hand-digging or use of a hydraulic or pneumatic soil excavation
tool is the least disruptive way to locate roots for pruning. Although mechanical root
pruners make clean cuts, they are non-selective. A backhoe bucket, dozer blade or
trencher will typically pull, rip or shatter the larger root, causing additional damage
toward the tree. Once the roots that interfere with the structure being built, e.g.,
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foundations, footings, retaining wall, curbs, etc., are exposed, they should then be cut
perpendicular to their long axis using a hand-saw, ‘carbide-tipped chainsaw’ or sharp ax,
depending on size. Roots that are pruned in this manner typically regenerate new roots
from near the cut. Roots exposed by excavation should be protected from exposure to
sun and desiccation. Exposed roots that can not be covered with soil by the end of the
day should be covered with moistened burlap or similar material.
Roots can generally be cut in a non-selective manner when excavating near of beyond the
dripline. Ripped, splintered or fractured portions of roots however, should be re-cut. The
damaged portion should be removed using sharp tools. The cut should be flat across the
root with the adjacent bark intact. Wound dressings should not be applied to pruned or
damaged roots except when recommended for disease, insect or sprout control.
The best approach to avoid water-deficit injury following root loss during the growing
season is to provide ample irrigation. Irrigation should be considered prior to, during,
and after root pruning. Watering schedules should also consider local soil conditions,
climate, topography, time of year, species adaptability, extent of root pruning and tree
health. If possible, irrigate the tree 7 to 10 days prior to excavation so that there is an
adequate reservoir of soil water. Water can be delivered to large construction sites via
water-tank trucks and applied directly to affected trees or stored nearby in plastic tanks.
On relatively flat terrain, a 6 to 8 inch soil berm at the tree’s dripline should be
constructed to act as a watering basin. On steep terrain, soaker hoses should be used.
They can be placed across the slope or spirally around the trunk, from about six feet away
to the dripline. In addition, a two to four inch layer of wood chip mulch should be
applied to as much of the root zone as possible to retard soil water loss.
Pruning foliage to compensate for root loss is not supported by scientific research and
likely to result in slower recovery. Fertilization to stimulate root growth is generally
unwarranted and may be counterproductive.
Trenching within the Tree Protection Zone
Trenching for underground utilities should be routed around the TPZ. When this is
unavoidable, trenching within the TPZ should be done by ‘hand’ or using a pneumatic or
hydraulic soil excavation tool, carefully working around larger roots. Roots larger than
1 ½ inches in diameter should not be cut. Dig below these roots to route utilities or
install drains. A combination of tools can also produce satisfactory results, for example,
a skillful backhoe operator under the arborist’s supervision can dig down several inches
at a time and detect larger roots by ‘feel’ (resistance). At that point, as assistant can
expose the root and dig around it. In this manner, the backhoe can then continue
extending the trench though the TPZ. Tunneling (boring) through the TPZ is the
preferable alternative. For most large trees, tunneling depth should be at least 36 inches.
Tunneling should begin at the edge of the TPZ, but no closer than a distance equal to one
foot of clearance for each inch of tree DBH. Tunnels should also be offset to either side
of the trunk. For trenching that extends only part way into TPZ, consider trenching
radially to the tree trunk, as this is less harmful than tangential trenching. All trenches
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made within the TPZ should be backfilled as quickly as possible to prevent root and soil
desiccation.
Managing Root Injured Trees
Root-pruned trees should be monitored for symptoms of water-deficit injury for a
specified period following root pruning. Irrigation should be considered prior to, during,
and after root pruning. Irrigation schedules should consider local soil conditions, climate,
topography, time of year, species tolerance, extent of root pruning and tree health.
Grade Change: Fill Soil
Fill soil placed within the root zones of trees can have an adverse effect, particularly if
the soil is compacted to support a structure or pavement. Soil compaction reduces
aeration and water infiltration. Fill soil, die to textural changes, can also prevent water
from penetrating the original soil layer below where the roots are. Furthermore, soil
placed against the root crown and lower trunk can lead to root disease problems,
especially if the soil near the trunk remains moist during the summer from irrigation.
Alternatives to placing fills over roots zones shall be considered and proposed as
appropriate.
Protected Tree Report: Survey, Encroachment and Protection Plan
758 Hampton Rd., Arcadia, 91006
Michael Crane, RCA #440. July 2018
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AUTHOR’S CREDENTIALS
Protected Tree Report: Survey, Encroachment and Protection Plan
758 Hampton Rd., Arcadia, 91006
Michael Crane, RCA #440. July 2018
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CERTIFICATION OF PERFORMANCE
I, Michael Crane, certify that:
• I have personally inspected the tree(s) and the property referred to in this report and have
stated my findings accurately.
• I have no current or prospective interest in the vegetation or the property that is the
subject of this report and have no personal interest or bias with respect to the parties
involved.
• The analysis, opinions, and conclusions stated herein are my own and are based on
current scientific procedures and facts.
• My analysis, opinions, and conclusions were developed and this report has been prepared
according to commonly accepted arboricultural practices.
• No one provided significant professional assistance to me, except as indicated within the
report.
• My compensation is not contingent upon the reporting of a predetermined conclusion that
favors the cause of the client or any other party not upon the results of the assessment, the
attainment of stipulated results, or the occurrence of any subsequent events.
I further certify that I am a member in good standing of the American Society of
Consulting Arborists and the International Society of Arboriculture. I have been
involved in the field of Horticulture in a full-time capacity for a period of more than 25
years.
Signed: ____________________________
Registered Consulting Arborist #440; American Society of Consulting Arborist
Board Certified Master Arborist #WE 6643B; International Society of Arboriculture
Licensed California Agricultural Pest Control Adviser #AA08269
July 27, 2018
Date: ______________________________