STUDY PROVES VILLAGE PERMANENTLY DAMAGED TREES
WITH 2001 SEVERE PRUNING POLICY

In October 2001 residents funded a study of "Area A" after the Village rejected repeated requests for a study. Residents were shocked by the findings of Dr. Thomas Green Ph.D. While they knew their trees had been disfigured, they had no idea of the extent of the damage the severe pruning had caused to the health of the trees. Green warns that the pruning was needlessly severe, violated professional pruning standards, and that the Village needs to allocate resources to the damaged area to save the trees. To date the Village has not responded to the findings of Dr. Green's study. In fact, a letter from the citizens forestry commission states that commission members, who are not tree experts, do not agree with Dr. Green's findings. The butchering of "Area A" by the Village, the reasons for the butchering and who is responsible, has never been discussed in a public forum.

THOMAS L GREEN Ph.D.
Plant Pathologist & Tree Pest Consultant
103 E 1000 Macomb, IL 61455
(309) 833?5415

RE: Evaluation of Oak Park Tree Pruning
On 26 October 2001, at the request of the Oak Park Citizen's Tree Rescue I conducted an evaluation of the recent pruning of some of Oak Park's parkway trees.

OVERVIEW
1. A majority of the trees recently pruned on S. Scoville, S. Elmwood, E. Pleasant, E. Randolph and E. Washington have been incorrectly pruned in accordance with ANSI A 300, TreePruning Guidelines, and the Oak Park Tree TRIMMING SPECIFICATIONS

2. Some trees trimmed by Village of Oak Park employees have been incorrectly pruned in accordance with ANSI A 300 and Tree Pruning Guidelines.

3. The TRIMMING SPECIFICATIONS that the Village of Oak Park uses for outside contractors are vague and need to be more specific.

4. The pruning of the parkway trees mentioned in #1 & # 2 above is considered to be too severe for a 4-year cycle. Many of the trees will be adversely affected as a consequence of such a severe pruning. Large branches were removed unnecessarily that will provide entry points for decay fungi resulting in hazardous trees in the future.

5. The trees pruned in the 100 block of S. East St. should be used as a model for future parkway tree pruning in Oak Park.

Response to questions asked by Kathryn Jonas in 16 October 2001 letter
"Specifically, we would like you to address the following matter as they relate to compliance with the contract pruning heights and ANSI 300 tree pruning practices which have been accepted by the Illinois Arborist Association, the National Arborist Association and the International Society of Arboriculture:

1. Q: the sidewalk and streetside pruning heights in light of a 4 year pruning cycle.
Few communities are able to prune their trees on a 4-year cycle; many have a 5-year cycle or longer. Considering the size of Oak Park, it is possible to have a 4-year cycle. The trees that I observed pruned on S. Scoville, S. Elmwood, E. Pleasant, E. Randolph and E. Washington have been pruned much too severely for a 4-year cycle. Only a few branches need to be pruned if you are coming back to the tree in 4 years. The type of pruning observed is considered to be too severe for even a longer than 4-year cycle.

2. Q: the amount of canopy, foliage removed from the trees.
ANSI A300, ISA's Tree Pruning Guidelines, and other references state that less than 25% of the foliage should be removed within an annual growing season. Almost all of the trees pruned on S. Scoville, S. Elmwood, E. Pleasant, E. Randolph and E. Washington had more than 25% of their foliage removed at the time they were pruned. Also, trees pruned by Oak Park Village employees exceeded 25% (see Table 1).

3. Q: the location of the remaining foliage on the trees
ANSI A300, ISA's Tree Pruning Guidelines, and other references state that 50% of the foliage should be in the bottom 2/3 of the tree. Most all of the trees pruned on S. Scoville, S. Elmwood, E. Pleasant, E. Randolph and E. Washington have 100% of their foliage in the upper 1/2. Some have 100% of their foliage in the upper 1/3. Also, most of the trees listed in Table 1 pruned by Oak Park Village employees have violated the 2.3 rule. Many of the trees are lions-tailed. Oak Park's TRIMMING SPECIFICATIONS are vague in that it says "B. Raise all lower branches and hanging branches to a minimum height of 16feet where practicable. Balance tree evenly. Prune to maintain 8' pedestrian clearance and 16' vehicular clearance for a four year period." There was no need to prune above 16' on the street side or 8' on the sidewalk side. Branches that are parallel with the parkway and do not extend into the street or sidewalk do not necessarily need to be pruned. Most trees were pruned to 20' or higher on all sides resulting in lions tailing and violation of the 2/3 rule.

4. Q: the structure, character of the individual tree species following pruning
It appears all trees were uniformly raised (lower branches removed for low clearance) regardless of individual characteristics. For example, some of the pyramidal Littleleaf Linden trees have been pruned to their top half or less leaving a very small crown resulting in deformation. Likewise, several Ginkgos were deformed by raising to their top half or top third. The trees pruned in the 100 block of S. East street were pruned according to their individual species leaving trees representative of their species

5. Q: the number and location of cuts made
As mentioned above cuts above 16' on the street side and 8' on the sidewalk side were unnecessary. In many cases branches with close vertical spacing were removed. Branches with close vertical spacing should not be removed in the same year.

6. Q: any effects on the health, vigor, storm susceptibility, or lifespan of the pruned trees that we can expect to see in the next few years
Pruning >25%: Probably the most serious problem that can cause immediate effects is the removal of greater than 25% of the foliage in one year. The scientific literature shows that when more than 25% is removed it can cause stress, tree decline and death. In some cases more than 50% was removed. Removal of foliage reduces the sugar the tree produces needed for its survival. Moving all of the sugar production to the top and end of branches reduces the sugar going to the trunk and branches necessary for taper and restricts the amount going to the roots at the other end. The lack of foliage shading the trunk can result in higher bark temperatures resulting in sunscald of the bark. Newly exposed branches can also sunscald in the winter. Sunscald can kill the bark. Stressed trees are more prone to attack by canker fungi and wood boring insects. Stressed trees lack the water and other chemicals needed to keep the canker fungi from attacking branch and trunk bark. Stressed trees send out chemicals that attract wood boring insects. Streets, sidewalks, utility infrastructure, salt, grass competition and other restrictions, limit the tree roots in parkways. Now, there will be more light and heat in the root zone. In July and August, when it is hot and dry, lack of water can cause leaf scorch (i.e. loss of water faster from leaves than it is being absorbed by roots). Scorched leaves have dead tissue on leaf margins and/or between the veins. The dead tissue means an additional loss of sugar production.

Lion's Tailing: Lion's Tailing is the removal of an excessive number of inner, lateral branches from parent (scaffold) branches. According to ISA's Tree-Pruning Guidelines, and other references lion's tailing is not an acceptable pruning practice. The loss of foliage along the trunk and branches means they get less sugar for wood growth. Wood growth is important for scaffold branches so they have taper. Taper (wider at the base) is necessary for strength. Lion's tailed branches have all the foliage on the end. High winds, ice and heavy snow loads on the ends of the branches can produce enough force to break the skinny branches. Those interior small branches help break up wind and produce sugar for taper. I would expect more broken branches on the trees that have been lion's tailed.

Unnecessary removal of permanent branches and decay: ISA's Tree Pruning Guidelines provides information on how to train newly planted trees. Temporary branches are to be removed when they are small. Permanent branches are left to provide the support of the crown. Permanent branches should not be removed. They leave large wounds that seldom close before the open wood begins to decay. Decay in trees is governed by the genetics of the species. Some compartmentalize decay well and others do not. With all the wounds from the removal of the permanent branches it is expected to cause decay in many of these trees. Decay within the trees will weaken the tree's ability to support itself, resulting in some trees becoming hazardous. Also, the removal of branches with little vertical spacing in the same year can result in the death of the bark between the branches making a larger wound than just the branch wound. In the next 5-20 years I expect loss of trees from decay as a consequence of the pruning of branches that did not need to be removed.

7. Q: explanation of excessive suckering on pruned trees
Suckers are new shoots that arise from the roots or understock. Watersprouts are new shoots that arise from the trunk or branches (above the understock). Many trees respond to excessive pruning by producing watersprouts and/or suckers. Watersprouts are weakly attached branches and are often vigorous and vertical. I expect to see many trees producing watersprouts, most of which should be pruned annually. If not pruned until 4 years from now, many will become large enough to leave open wounds that will permit decay fungi to enter. On severely pruned trees individual watersprouts that are growing horizontally in the proper direction should be left to reestablish the 2/3 rule, produce sugar for branch taper and help the branches recover from lion's tailing. These should be selected next year rather than wait until the next pruning cycle. Typically and incorrectly, municipalities require contractors to remove all watersprouts. This often causes the removal of the lateral branches on the scaffold branches resulting in lion's tailing. A watersprout growing horizontally and in the right direction or interior lateral branch does not need to be removed. Bottomline: the excessive pruning may result in a need to prune the trees before their 4-year cycle.

8. Q: What do you think about how the large elms were pruned in relation to the Village specifications, their health and Dutch elm disease?
I observed that many of the Village's large elms were pruned much higher than necessary according to the TRIMMUNG SPECIFICATIONS, i. e. above the first main crotch (C.). The elms can be trimmed so the "cathedral arch" effect is achieved without removing watersprouts, and inner lateral branches resulting in lion's tailing and unnecessary removal of permanent branches above 16'. Fall pruning will prevent the spread of Dutch elm disease because the bark beetles are not active. However, too severe of a pruning, e.g. removal of more than 25% of the foliage, could create stress which may make the tree attractive to bark beetles next summer that can bring in DED. Starting the pruning on 1 November is past the beetle period and when the tree is dormant. However, this is also the period that the fungal decay organisms (spores) are most abundant which increases the chances of their colonization in the open wounds. The best time for pruning is after Thanksgiving until just before budbreak in the late winter. The fungal decay spores are less active in cold weather and other non-decay microorganisms colonize the open wounds and produce chemicals that inhibit the decay fungi.

RECOMMENDATIONS:
1. More Comprehensive Tree Pruning Specifications: In answering your questions I hope you can encourage your Village to write more comprehensive tree pruning specifications for any future tree pruning. I would recommend using Downers Grove or Highland Park pruning specifications as a model.

Experience: I am familiar with several communities that require outside contractors to have had previous experience with trimming parkway trees. Their experience of trimming trees on private property within the Village, or doing emergency storm damage cleanup, or clearance for developers should not qualify them for such experience.

ISA Certified Arborist: The specifications should include proof of ISA Certification and that an ISA Certified Arborist be present at all times when a crew is doing work.

Proficiency in English: There should be a requirement that at least one crew member be proficient in speaking English. Reference to ANSI Standards and other technical references: The specifications should refer to ANSI 2133.1-2000, ANSI A300 (Part 1)-2001, ISA's Tree-Pruning Guidelines, OSHA Regulations and other appropriate technical publications

Prebid Inspections: Contractors who can qualify for bidding should be shown what is to be pruned and what the expected results should look like at a prebid meeting. This is where the 100 block of S. East Ave. can be used as a model for expected results (I believe that there are a few branches on several trees on this block that still need to be raised before it is used as a model).

Other: There are other specifications that need to be included as needed so that the trees are pruned the way the Village desires to have them pruned without interpretation by the contractor.

2. Municipal Pruning: Tree pruned by municipal employees should not remove > 20% of the foliage, should not violate the 2/3 rule, should not lion's tail or otherwise be contrary to ANSI 2133.1?2000, ANSI A300 (Part 1)-2001 and ISA's Tree-Pruning Guidelines.

3. More Education for Citizens' Forestry Commission, Village Residents and Village Employees: The Village budget should provide funding for its forestry employees to attend professional meetings (e.g. annual IAA meeting) and the various educational training programs offered in the Chicago region. The Village should support and encourage ISA Certification for all forestry employees. Members of the Citizens' Forestry Commission should be encouraged to join the Illinois Arborist Association, attend professional meetings, participate in educational training programs and actively work to learn more about arboriculture. The Village, the Citizens' Advisory Commission, and interested residents should work together to develop a comprehensive Oak Park Arboriculture Manual. This manual should provide all Village ordinance information, specifications for pruning, planting, removal and other tree maintenance, special tree programs, and information about tree care. This can provide a useful educational tool for all Village residents. It can be made available to all with copies at City Hall, the Library and on the Internet. The manual used in Downers Grove is excellent and can serve as a model.

4. Hiring an Outside Certified Arborist to Oversee Tree Pruning: If the next pruning cycle for municipal trees is using original specifications, it may be necessary to bring in someone knowledgeable in municipal tree trimming and who can ensure trees are trimmed in compliance with ANSI A300 and, ISA's Tree-Pruning Guidelines. Whoever is doing the pruning should have the trees look like those in the 100 block of S. East Ave. when they are finished pruning. It should be noted that there are trees (Maples) in the 100 block of S. East Ave. that have been lion's tailed during a pruning prior to those recently done, and these trees should not be considered as a model for pruning.

5. Young Tree Pruning Program and Subordination: Each young (immature) tree planted should be on a regular pruning program to remove temporary branches and develop the permanent tree structure (see, ISA's Tree-Pruning Guidelines). Once permanent branches are developed they should not be removed without good reason. Young trees with codominant stems should be pruned by subordination pruning. Information on subordination pruning can be found in An Illustrated Guide to Pruning by Ed Gilman and is available from the ISA. People doing the pruning of immature and mature trees should be knowledgeable in the principle of subordination. The ISA's Tree Pruning Guidelines provides information on pruning mature trees.

TABLE 1.

Observations of individual trees pruned
(back to Question 2)

REMARKS:
>25%: This means that more than 25% of the foliage was removed when pruned.

2/3 rule: This means that the tree does not meet the 2/3 rule where '/Z of the foliage is in the lower 2/3 of the tree.

Lion's Tail: This means that all the interior and lower lateral branches have been removed leaving all of the foliage on the end of the branch.

Watersprouts: These are weakly attached new shoots that grow in response to severe pruning and exposure of adventitious buds to light.

Who is Dr Green?

Thomas L. Green Ph.D.
Associate Professor, Agriculture Department,
College of Business and Technology
Western Illinois University
Macomb, IL 61455

EDUCATION:
Ph.D. 1979 Iowa State University, Plant Pathology Dissertation title: Symbiotic Relationships Among Alnus and its Mycorrhizae and Actinorhizae

M.S. 1971 Western Illinois University, Botany B.S. 1969 Western Illinois University, Zoology

TEACHING:
Fall 1993 - Present
Fall Forestry 208, Dendrology; Forestry 306 Arboriculture; Horticulture 486 Nursery Management (even yrs); Horticulture 387 Commercial Fruit Production (odd yrs) Spring Forestry 200, Introduction to Forestry; Forestry 209, Basic Tree Worker Skills; Forestry 407, Urban Forest Management; Forestry 409 Arborist Supervisor Practicum

EXPERIENCE:
1980-2001 Consulting Arborist; specialization in tree inventory; plant health care
1980-1993 Research Plant Pathologist, Morton Arboretum, Lisle, IL
1979-1980 City Forester, Burlington, Iowa
1974-1979 Graduate Assistant, Dept. Plant Pathology, Iowa State University
1971-1974 Assistant S2, 49`h Air Defense Artillery Group, Ft. Lawton, WA

PROFESSIONAL ACTIVITIES:
Professional association positions:
President, Illinois Arborist Association, Sept. 1998- Nov. 1999
President Elect, Illinois Arborist Association, Nov. 1997-Sept. 1998
Vice President, Illinois Arborist Association, Nov. 1996 -Nov. 1997
Executive Director, International Ornamental Crabapple Society, 1984-1997

Professional association memberships:
International Society of Arboriculture 1979-present
Illinois Arborist Association 1983-present
National Arbor Day Foundation
International Ornamental Crabapple Society
International Oak Society
National Association of Colleges and Teachers of Agriculture
Association for Temperate Agroforestry
Society of American Foresters
The Midwest Association of Golf Course Superintendents
National Association of Biology Teachers

OTHER ACTIVITIES
Scoutmaster Troop 303, Macomb, IL

TREE INVENTORIES CONDUCTED BY THOMAS L. GREEN
GOLF COURSE TREE INVENTORIES:
Arrowhead Golf Club 1984
Aura Country Club 1989
Biltmore Country Club 1987
Bryn Mawr Country Club 1989
Butler National Country Club 1993
Butterfield Country Club 1994
Edgewood Valley Country Club 1994
Elgin Country Club 1990
Forest Hills Country Club 1990
Glen Oak Country Club 1989
Green Acres Country Club 1999
Hinsdale Golf Club 1990
Itasca Country Club 1992
Ivanhoe Club 1993
Janesville Country Club 1998
Joliet Country Club 1991
LaGrange Country Club 1991
Lake Shore Country Club 1997
Medinah Country Club Course 3 1984
Medinah Country Club Courses 1 & 2 1988
Old Elm Club 1992
Ozaukee Country Club 1986
Pottawatomie Golf Course 1992
Ravisloe Country Club 1995
Ridge Country Club 1994
Ridgemoor Country Club 1987
West Point Military Academy Golf Course 2000

TREE PRESERVATION FOR GOLF COURSES UNDER CONSTRUCTION
Geneva National Golf Club, Lake Geneva, Wisconsin 1990
Ivanhoe Country Club, Ivanhoe, IL 1987-88
Oak Brook Hills Golf Club, Westmont, IL 1985
St Charles Country Club, 1987

COLLEGE CAMPUS TREE INVENTORY
Lake Forest College, Lake Forest, IL 1990-92
Northeastern Illinois University, Chicago, IL 1989
United States Military Academy, West Point, NY 1996-7 and 2000

PARK TREE INVENTORY
Lincoln Park, Chicago, IL 1991
Reed Keppler Park, West Chicago, IL 1982
Sayre Park, Chicago, IL 1985

CEMETERY TREE INVENTORY
Graceland Cemetery, Chicago, IL

OTHER
Palos Community Hospital, Palos Heights, IL