016 Tree Evaluation Report, Greenline Building B, 6-26-2018
EVALUATION OF INTERIOR TREES
at the
GREENLINE BUILDING B SITE
Weyerhaeuser Way South
Federal Way, WA 98003
File #17-104236-UP & 17-104237-SE
Revised June 26, 2018
September 6, 2017
PREPARED FOR:
Federal Way Campus, LLC
Attn: Tom Messmer
11100 Santa Monica Boulevard
Los Angeles, CA 90025
PREPARED BY:
GILLES CONSULTING
Brian K. Gilles, Consulting Arborist
ISA Certified Arborist # PN-0260A
ASCA Registered Consulting Arborist # RCA-418
ISA TRAQ Qualified
ISA TRAQ Certified Instructor
Evaluation of Trees at the Greenline Building B Site
Weyerhaeuser Way South, Federal Way, WA 98003
Gilles Consulting
June 26, 2018
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CONTENTS
ASSIGNMENT .................................................................................................................. 3
SCOPE AND METHODOLOGY ................................................................................... 3
Evaluation of Trees & Status Determination .................................................................. 3
Additional Testing .......................................................................................................... 4
Failure ............................................................................................................................. 4
OBSERVATIONS ............................................................................................................. 4
Tall Trees Observed: ....................................................................................................... 4
Small Native Trees/Small Shrubs Observed ................................................................... 4
Low Growing Native Shrubs and Ground Covers Observed: ........................................ 5
Invasive Species Observed: ............................................................................................ 5
Tree Data ......................................................................................................................... 5
DISCUSSION .................................................................................................................... 5
Required Tree Retention ................................................................................................. 5
Minimum Tree Density Calculations .............................................................................. 6
Tree Protection Measures ............................................................................................... 7
WAIVER OF LIABILITY ............................................................................................... 7
ATTACHMENTS ............................................................................................................. 9
Evaluation of Trees at the Greenline Building B Site
Weyerhaeuser Way South, Federal Way, WA 98003
Gilles Consulting
June 26, 2018
Page 3 of 17
ASSIGNMENT
Tom Messmer, of the Federal Way Campus LLC, contracted with Gilles Consulting to
develop this report of the trees at the Greenline Building B Site on Weyerhaeuser Way South.
In compliance with the Weyerhaeuser Company Concomitant Pre-Annexation Developer
Agreement (Agreement), dated August 23, 1994, between the Weyerhaeuser Company and
the City of Federal Way, the 1994 definitions of “signi ficant trees” was utilized to measure
and evaluate the condition of the trees in the interior portion of the property.
Note: See Managed Forest Buffer Management Plan at the Greenline Building B Site, dated
June 26, 2018 for a discussion of the Managed Forest Buffer (MFB) on-site. See Tree Data
for 32 Acre Site, dated 26 June 2018 for a complete dataset of significant and non-significant
trees on the Building B Site.
SCOPE AND METHODOLOGY
Evaluation of Trees & Status Determination
First, an inventory of the existing vegetation of the property was conducted. This
included documenting the species present, their relative size, and their condition. Each
tree was tagged with a unique number and its trunk measured at 4.5 feet above the
average ground level to determine diameter, (DBH).
Following the 1994 Federal Way City Code (FWCC) Section 22-1568(c)(6), we used the
definition of a significant tree to determine the status of each tree encountered. As
defined in 1994 FWCC Sec. 22-1568(b) “a Significant Tree is a tree that is:
1) Twelve inches in diameter or 37 inches in circumference measured four and one-
half feet above the ground; and
2) In good health; and
3) Not detrimental to the community (e.g. is not diseased, dying, or likely of falling
into public open space or right-of-way, etc.) or obscuring safe sight distance
requirements. Significant trees shall not include red alder, cottonwood, poplar or
big leaf maple.”
Using 1994 FWCC Section 1568(c) Standards, calculations for significant tree retention
were calculated and a Tree Retention Plan has been included in the permit documents but
not as a part of the MFB Plan. This is because all of the trees in the MFB are to be
retained—unless they pose a threat to life and property. These retained trees shall be
protected as defined in the Tree Protection Measures section below.
Trees were also evaluated for risk to determine whether or not any of the trees proposed
for retention pose an unacceptable level of risk to life and property. The goal was to
identify any potential hazard trees and manage them down to a safe level during clearing
and grading phases of the project. We followed the protocol of the International Society
Evaluation of Trees at the Greenline Building B Site
Weyerhaeuser Way South, Federal Way, WA 98003
Gilles Consulting
June 26, 2018
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of Arboriculture known as Tree Risk Assessment Qualification, TRAQ. This is a
scientifically based process that includes a roots to shoots evaluation of each tree to
determine health, structural stability, and likelihood of failure. Trees were then rated as
Significant or Non-Significant based upon criteria a – c above and the size of their trunk
at 4.5 feet as measured with a diameter tape measure.
Additional Testing
The trees all presented signs and/or symptoms that were readily discernible using the
visual tree evaluation system of a Level II risk assessment. These signs and/or symptoms
indicate extensive internal decay and/or structural defects in some trees and solid trunks
and lack of disease in others. Therefore, no additional tests were performed during this
site visit.
Failure
While no one can predict with absolute certainty which trees will or will not fail, we can,
by using this scientific process, assess which trees are most likely to fail and take
appropriate action to minimize injury and damage.
OBSERVATIONS
Tall Trees Observed:
Big Leaf Maple, Acer macrophyllum
Cascara, Rhamnus purshiana
Douglas Fir, Pseudotsuga menziesii
Oregon Ash, Fraxinus latifolia
Pacific Madrone, Arbutus menziesii
Pacific Willow, Salix lasiandra
Paperbark Birch, Betula papyrifera
Red Alder, Alnus rubra
Western Hemlock, Tsuga heterophylla
Western Red Cedar, Thuja plicata
The trees were rated on a scale from Dead, to Dying, to Poor, to Fair, to Good, to
Very Good, to Excellent.
The shrub and ground cover layers consisted of plants typical of lowland Puget Sound
that include:
Small Native Trees/Small Shrubs Observed
Vine Maple, Acer circinatum
Western Hazelnut, Corylus cornuta
Indian Plum, Oemleria cerasiformis
They are all in Fair to Excellent Condition.
Evaluation of Trees at the Greenline Building B Site
Weyerhaeuser Way South, Federal Way, WA 98003
Gilles Consulting
June 26, 2018
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Low Growing Native Shrubs and Ground Covers Observed:
Salal, Gaultheria shallon
Trailing Blackberry, Rubus ursinus
Snowberry, Symphoricarpos albus
Oregon Grape, Mahonia nervosa
Bracken Fern, Pteridium aquilinum
They are all in Fair to Very Good Condition.
Invasive Species Observed:
Himalayan Blackberry, Rubus discolor
English Ivy, Hedera helix
English Holly, Ilex aquifolium.
While small in number they appear healthy at this time.
Data for Greenline Building B:
Building B
Significant Trees (Interior) 527
Significant Trees (MFB) 80
TOTAL 607
o A complete data set of all trees identified within both the Greenline
Building A and B projects can be found in the Tree Data for 32 Acre
Site dated 26 June 2018.
o There are a total of 527 significant trees in the interior of the Greenline
Building B site.
Tree Data
See Tree Data for 32 Acre Site, dated 26 June 2018, for a complete dataset of evaluated
significant trees on the property.
DISCUSSION
Required Tree Retention
Retention of course, needs to take into account the location of the trees and the location
of the proposed improvements. However, strongly advocate retaining as many more trees
as possible over the minimum required if development allows. This affords significant
flexibility during construction when unforeseen circumstances and events require the
removal of trees that were at first planned for retention. If there is a bank of extra
Evaluation of Trees at the Greenline Building B Site
Weyerhaeuser Way South, Federal Way, WA 98003
Gilles Consulting
June 26, 2018
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Significant Trees somewhere else on the property they can be switched out with a tree or
more that needs to be removed unexpectedly.
Minimum Tree Density Calculations
The 1994 FWCC Tree Code requires that each project have a minimum density of at least
25% of the Significant Trees retained. Acreages for project area can be found in
Attachment 1, Exhibits, Arborist Site Map.
32-acre Site (INTERIOR)
1245 significant trees/ 27.86 ac = 45 significant trees/ac (INTERIOR)
*1427 TOTAL SIGNIFICANT TREES ON-SITE (INTERIOR + MFB)
1572F (Building B)
Project Limits B MFB 2.51 ac
Project Limits B INTERIOR 11.79 ac
Project Limits B TOTAL 14.3 ac
Total Significant Trees B
Total Significant Trees B MFB 80
Total Significant Trees B
INTERIOR 45 x11.79 ac= 527
607
Preserved Area B 2.17 ac
Tree Preservation B 45 x2.17 ac= 97
Total Significant Trees
Preserved B
Tree Retention B 607 x25% 152
Total Significant Trees B MFB 80
Tree Preservation B 97
177
% Tree Retention 177/607= 0.292 OR 29.2%
Replacement Trees B 152-177= -25
Evaluation of Trees at the Greenline Building B Site
Weyerhaeuser Way South, Federal Way, WA 98003
Gilles Consulting
June 26, 2018
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Tree Protection Measures
In order for trees to survive the stresses placed upon them in the construction process,
tree protection must be planned in advance of equipment arrival on site. If tree protection
is not planned integral with the design and layout of the project, the trees will suffer
needlessly and possibly die. With proper preparation, often costing little or nothing extra
to the project budget, trees can survive and thrive after construction. This is critical for
tree survival because damage prevention is the single most effective treatment for trees
on construction sites. Once trees are damaged, the treatment options available are
limited.
The minimum Tree Protection Measures in Attachment 2, Tree Protection Measures are
on three separate sheets that can be copied and introduced into all relevant documents
such as site plans, permit applications and conditions of approval, and bid documents so
that everyone involved is aware of the requirements. These Tree Protection Measures are
intended to be generic in nature. They will need to be adjusted to the specific
circumstances of your site that takes into account the location of improvements and the
locations of the trees.
WAIVER OF LIABILITY
There are many conditions affecting a tree’s health and stability, which may be present
and cannot be ascertained, such as, root rot, previous or unexposed construction damage,
internal cracks, stem rot and more which may be hidden. Changes in circumstances and
conditions can also cause a rapid deterioration of a tree’s health and stability. Adverse
weather conditions can dramatically affect the health and safety of a tree in a very short
amount of time. While I have used every reasonable means to examine these trees, this
evaluation represents my opinion of the tree health at this point in time. These findings
do not guarantee future safety nor are they predictions of future events.
The tree evaluation consists of an external visual inspection of an individual tree’s root
flare, trunk, and canopy from the ground only unless otherwise specified. The inspection
may also consist of taking trunk or root soundings for sound comparisons to aid the
evaluator in determining the possible extent of decay within a tree. Soundings are only
an aid to the evaluation process and do not replace the use of other more sophisticated
diagnostic tools for determining the extent of decay within a tree.
As conditions change, it is the responsibility of the property owners to schedule
additional site visits by the necessary professionals to ensure that the long-term success
of the project is ensured. It is the responsibility of the property owner to obtain all
required permits from city, county, state, or federal agencies. It is the responsibility of
the property owner to comply with all applicable laws, regulations, and permit
conditions. If there is a homeowners association, it is the responsibility of the property
Evaluation of Trees at the Greenline Building B Site
Weyerhaeuser Way South, Federal Way, WA 98003
Gilles Consulting
June 26, 2018
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owner to comply with all Codes, Covenants, and Restrictions (CC&R’s) that apply to tree
pruning and tree removal.
This tree evaluation is to be used to inform and guide the client in the management of
their trees. This in no way implies that the evaluator is responsible for performing
recommended actions or using other methods or tools to further determine the extent of
internal tree problems without written authorization from the client. Furthermore, the
evaluator in no way holds that the opinions and recommendations are the only actions
required to insure that the tree will not fail. A second opinion is recommended. The
client shall hold the evaluator harmless for any and all injuries or damages incurred if the
evaluator’s recommendations are not followed or for acts of nature beyond the
evaluator’s reasonable expectations, such as severe winds, excessive rains, heavy snow
loads, etc.
This report and all attachments, enclosures, and references, are confidential and are for
the use of the client concerned. They may not be reproduced, used in any way, or
disseminated in any form without the prior consent of the client concerned and Gilles
Consulting.
Thank you for calling Gilles Consulting for your arboricultural needs.
Sincerely,
Brian K. Gilles, Consulting Arborist
ISA Certified Arborist # PN-0260A
ASCA Registered Consulting Arborist # RCA-418
ISA TRAQ Qualified
ISA TRAQ Certified Instructor
Evaluation of Trees at the Greenline Building B Site
Weyerhaeuser Way South, Federal Way, WA 98003
Gilles Consulting
June 26, 2018
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ATTACHMENTS
ATTACHMENT 1 - EXHIBITS .................................................................................... 10
ATTACHMENT 2 - TREE PROTECTION MEASURES ......................................... 11
ATTACHMENT 3 - BIBLIOGRAPHY........................................................................ 17
Evaluation of Trees at the Greenline Building B Site
Weyerhaeuser Way South, Federal Way, WA 98003
Gilles Consulting
June 26, 2018
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ATTACHMENT 1 - EXHIBITS
Evaluation of Trees at the Greenline Building B Site
Weyerhaeuser Way South, Federal Way, WA 98003
Gilles Consulting
June 26, 2018
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ATTACHMENT 2 - TREE PROTECTION MEASURES
In order for trees to survive the stresses placed upon them in the construction process,
tree protection must be planned in advance of equipment arrival on site. If tree protection
is not planned integral with the design and layout of the project, the trees will suffer
needlessly and will possibly die. With proper preparation, often costing little, or nothing
extra to the project budget, trees can survive and thrive after construction. This is critical
for tree survival because damage prevention is the single most effective treatment for
trees on construction sites. Once trees are damaged, the treatment options available are
limited.
The following minimum Tree Protection Measures are included on three separate sheets
so that they can be copied and introduced into all relevant documents such as site plans,
permit applications and conditions of approval, and bid documents so that everyone
involved is aware of the requirements. These Tree Protection Measures are intended to
be generic in nature. They will need to be adjusted to the specific circumstances of your
site that takes into account the location of improvements and the locations of the trees.
Evaluation of Trees at the Greenline Building B Site
Weyerhaeuser Way South, Federal Way, WA 98003
Gilles Consulting
June 26, 2018
Page 12 of 17
TREE PROTECTION MEASURES
1. Tree Protection Fencing:
a. Tree Protection Fences will need to be placed around each tree or group of
trees to be retained.
i. Tree Protection Fences are to be placed according to the approved
limits of clearing.
ii. The area inside the fences is the Tree Protection Zone.
iii. The area outside the fences is the work zone or the construction
zone.
iv. Tree Protection Fences must be inspected prior to the beginning of
any clearing, grading, or construction work activities.
v. Nothing must be parked or stored within the Tree Protection
Fences—no equipment, vehicles, soil, debris, or construction
supplies of any sorts.
b. Signs:
i. The Tree Protection Fences need to be clearly marked with the
following or similar text in four inch or larger letters:
“TREE PROTECTION FENCE
DO NOT ENTER THIS AREA
DO NOT PARK OR STORE MATERIALS
WITHIN THE PROTECTION AREA
Any questions or concerns, call Brian K. Gilles at Gilles
Consulting
@ 425-417-0850”
2. Cement Trucks:
a. Cement trucks must not be allowed to deposit waste or wash out materials
from their trucks within the Tree Protection Fences.
3. Canopy Pruning:
a. The canopies of the edge trees may need to properly pruned to allow
building and construction clearance.
b. The pruning must be done by an International Society of Arboriculture,
(ISA) Certified Arborist using current industry standard pruning
techniques. (ANSI A300 Pruning Standards and ANSI Z131.1 Safety
Standards as well as all OSHA, WISHA, and local standards must be
followed.)
c. The pruning must be done from a lift truck to allow tip pruning and he
smallest cuts possible or by using clean climbing techniques.
Evaluation of Trees at the Greenline Building B Site
Weyerhaeuser Way South, Federal Way, WA 98003
Gilles Consulting
June 26, 2018
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d. Plant debris can be chipped and utilized on site for the mulch under the
preserved/retained trees.
4. Excavation:
a. When excavation occurs within the driplines of trees that are scheduled for
retention, the following procedure must be followed to protect the long
term survivability of the tree:
b. An International Society of Arboriculture, (ISA) Certified Arborist must
be working with all equipment operators.
i. The Certified Arborist should be outfitted with a shovel, hand
pruners, a pair of loppers, a handsaw, and a power saw (a
“sawsall” is recommended).
ii. The arborist must also have an air spade and compressor to blow
the soil away and expose the roots for proper root pruning.
c. The Hoe:
i. The hoe used at first must be a small landscape sized hoe with a
thumb attachment.
ii. The hoe must be placed to gently lift and break the sidewalk and
pull pieces of sidewalk away from the trunks.
iii. The disposal trucks must be placed in the parking lot to receive the
debris.
iv. A larger hoe can be utilized in the parking lot to break up the
sidewalk into small enough pieces to be efficiently loaded into the
trucks and hauled away.
1. The hoes are not allowed to break up the sidewalk on
unbroken sidewalk or over the tree roots within the
canopy/driplines of the trees.
d. The small hoe can then excavate down to its limits of depth.
e. The larger hoe can then take over the excavation to the proper depth and
of the rest of the site.
5. Tree Protection Fences will need to be placed around each tree or group of trees
to be retained.
a. Tree Protection Fences are to be placed according to the attached drawing
at a distance of not less than 5 feet outside the dripline of the tree or group
of trees to be saved.
b. Tree Protection Fences must be inspected prior to the beginning of any
demolition or construction work activities.
c. Nothing must be parked or stored within the Tree Protection Fences—no
equipment, vehicles, soil, debris, or construction supplies of any sorts.
6. Cement trucks must not be allowed to deposit waste or wash out materials from
their trucks within the Tree Protection Fences.
Evaluation of Trees at the Greenline Building B Site
Weyerhaeuser Way South, Federal Way, WA 98003
Gilles Consulting
June 26, 2018
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7. The Tree Protection Fences need to be clearly marked with the following or
similar text in four inch or larger letters:
“TREE PROTECTION FENCE
DO NOT ENTER THIS AREA
DO NOT PARK OR STORE MATERIALS
WITHIN THE PROTECTION AREA
Any questions or concerns, call Brian K. Gilles at Gilles
Consulting
@ 425-417-0850”
8. When excavation occurs near trees that are scheduled for retention, the following
procedure must be followed to protect the long term survivability of the tree:
a. An International Society of Arboriculture, (ISA) Certified Arborist must
be working with all equipment operators.
i. The Certified Arborist should be outfitted with a shovel, hand
pruners, a pair of loppers, a handsaw, and a power saw (a
“sawsall” type reciprocating saw is recommended).
b. The hoe must be placed to “comb” the material directly away from the
trunk as opposed to cutting across the roots.
i. Combing is the gradual excavation of the ground cover plants and
soil in depths that only extend as deep as the tines of the hoe.
c. When any roots of one inch diameter or greater, of the tree to be retained,
is struck by the equipment, the Certified Arborist should stop the
equipment operator.
d. The Certified Arborist should then excavate around the tree root by
hand/shovel and cleanly cut the tree root.
i. The Certified Arborist should then instruct the equipment operator
to continue.
9. Putting Utilities Under the Root Zone:
a. If it is necessary to place utilities within the dripline, it must be
accomplished with trenchless technology such as boring under the root
systems of trees (and other vegetation). This work shall be done under the
supervision of an ISA Certified Arborist.
b. This is to be accomplished by excavating a limited trench or pit on each
side of the critical root zone of the tree and then hand digging or pushing
the pipe through the soil under the tree. The closest pit walls shall be a
minimum of 7 feet from the center of the tree and shall be sufficient depth
to lay the pipe at the grade as shown on the plan and profile.
Evaluation of Trees at the Greenline Building B Site
Weyerhaeuser Way South, Federal Way, WA 98003
Gilles Consulting
June 26, 2018
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c. Tunneling under the roots of trees shall be done under the supervision of
an ISA Certified Arborist in an open trench by carefully excavating and
hand digging around areas where large roots are exposed. No roots 1 inch
in diameter or larger shall be cut.
d. The contractor shall verify the vertical and horizontal location of existing
utilities to avoid conflicts and maintain minimum clearances; adjustment
shall be made to the grade of the new utility as required.
Evaluation of Trees at the Greenline Building B Site
Weyerhaeuser Way South, Federal Way, WA 98003
Gilles Consulting
June 26, 2018
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Evaluation of Trees at the Greenline Building B Site
Weyerhaeuser Way South, Federal Way, WA 98003
Gilles Consulting
June 26, 2018
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ATTACHMENT 3 - BIBLIOGRAPHY
1. Dirr, Michael A. Manual of Woody Landscape Plants, Their Identification, Ornamental
Characteristics, Culture, Propagation, and Uses. Champaign: Stipes Publishing Company, 1990.
2. Dunster, Dr. Julian A., R.P.F., M.C.I.P. Documenting Evidence, Practical Guidance for Arborists,
First Choice Books, Victoria, BC, Canada. 2014.
3. Eric Allen, et al. Common Tree Diseases of British Columbia. Victoria: Canadian Forest Service,
1996.
4. Goheen, Ellen Michaels and Elizabeth A Willhite, Field Guide to the Common Diseases and Insect
Pests of Oregon and Washington Conifers, R6-NR-FID-PR-01-06.2006. USDA Forest Service, Pacific
Northwest Region.
5. 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.
6. Link, Russell, Landscaping for Wildlife in the Pacific Northwest, The University of Washington Press,
Seattle, WA. 1999.
7. Matheny, Nelda P. and Clark, James R. Evaluation of Hazard Trees. 2nd ed. Savoy: The International
Society of Arboriculture Press, 1994.
8. Matheny, Nelda P. and Clark, James R. Trees & Development, A Technical Guide to Preservation of
Trees During Land Development. Savoy: The International Society of Arboriculture Press, 1998.
9. Mathews, Daniel. Cascade -- Olympic Natural History. Portland, Oregon: Raven Editions with the
Portland Audubon Society, 1992.
10. Mattheck, Claus and Breloer, Helge. The Body Language of Trees, A Handbook for Failure Analysis.
London: HMSO, 1994.
11. Pacific Northwest Chapter-ISA. Tree Risk Assessment in Urban Areas and the Urban/Rural Interface.
Course Manual. Release 1.5. PNW-ISA: Silverton, Oregon, 2011.
12. Petrides, George A. and Wehr, Janet. A Field Guide to Eastern Trees, Eastern United States and
Canada including the Midwest. New York: Houghton Mifflin Company, 1998.
13. Scharpf, Robert F. Diseases of Pacific Coast Conifers. Albany, California: USDA Forest Service,
Agriculture Handbook 521, rev. June 1993.
14. Sinclair, Wayne A., Lyon, Howard H., and Johnson, Warren T. Diseases of Trees and Shrubs. Ithaca,
New York: Cornell University Press, 1987.
15. 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 a. Tree Structure Assessment). The International Society of Arboriculture
Press. Champaign. IL. 2011.
16. Watson, Gary W., and Neely, Dan, eds. Trees & Building Sites. Savoy: The International Society of
Arboriculture Press, 1995.