East Aurora, New York - A Village of Green

Village of East Aurora Community Forestry Management Plan

Executive Summary

Trees are recognized as significantly important to the quality of life enjoyed in East Aurora, and are considered integral to the right-of-way infrastructure. This plan defines this right-of-way infrastructure (street) to include pavement, curbs, utility strip or tree lawn, and trees. This Community Forest Management Plan (CFMP) is structured as a living document. Although the initial consideration is for fifteen (15) years, some components (e.g. monitoring trees significantly in decline) will require periodic, even annual, evaluation. Other details, such as site identification, will remain the same for several plans into the future.

The Community Forest Inventory completed in 2001 shall serve as the basis for management planning. Of the 5,423 sites evaluated, 3,278 sites were occupied with trees and present or future planting sites numbered 2,145. Evaluation of program implementation shall be based on this inventory providing the baseline site data. This assures consistency in future evaluations.

East Aurora has more trees per linear street mile than do most communities of Western New York. Properly located sites are to be maintained with trees, as possible. Poor sites will diminish over time, as tree replacements will not be made. A full complement of trees for the village allows for up to 3,954 trees of various sizes and species. Plan objective is to retain, or exceed, 3,278 trees in 2017.

Species diversity needs strengthening. Overall, a single genus should represent no more than 10% of the village tree population. At present, Acer, Maple genus represents 63% of trees in East Aurora. Tree size, ranging from newly planted to large, mature trees is reasonable, indicating many years of consistent tree care in the village. General vitality and tree vigor, however, indicate an aging population destined to require increased attention and resources. Due to past plantings by homeowners, many trees are too close, preventing many from expressing the dominant form desirable of the species. Competition for limited resources increases when trees lack adequate planting space.

Tree health is acceptable. Of the 3,278 trees evaluated, 79% were considered generally healthy. Only 6% were considered for immediate removal due to irreversible decline or death. One of the more serious threats to tree health in East Aurora is the cumulative decay effect caused by cutting roots to accommodate sidewalks. This policy must be reviewed. Cutting into the tree root collar area to allow placement of a new sidewalk may result in tree failure many years later. Stopping the practice of cutting into root collars is recommended. Twenty-five to 50 years will pass before the increasing risk from this practice is minimized.

Six hundred twenty-three (623) planting sites are available presently. An additional 1,522 potential sites cannot now be planted due to a recognized current site limitation. As the limitations diminish, these sites become available for planting. Of the 1,522 encumbered sites, most will not become available for planting during this 15-year planning period.

There are three aspects to implementation of the CFMP: tree planting, tree maintenance and tree removal. Recommendation is made to review at least three new policy areas: (1) Tree planting needs may require establishment of a fall planting program; (2) Tree maintenance should include early, routine raising of clear trunks to provide safe, but not excessive, street clearance for construction vehicles; and (3) Root-cutting to allow sidewalk maintenance is creating significant future problems.

Tree Planting

Stocking Levels - Potential for planting exists in all site categories (1, 2, 3, 4, 8, 9, and 10) except those deemed undesirable for the duration of this plan and beyond (5, 6, and 7). Please see Appendix for site category definitions. With a fully implemented management plan, East Aurora would manage approximately 3954 healthy trees, occupying only desirable sites. Currently, 1474 are in that category, establishing a stocking level of 37%. This is the figure that should be used for evaluation of the program in the future. It does not represent the actual stocking level in the village because many trees are currently present in sites that are not desirable. Also, some desirable sites are occupied with trees declining or dead.

Considering tree numbers only, East Aurora is 78% stocked. The role of tree planting is to place trees in desirable sites to supplement those already occupied. Over time, as trees decline and are removed, replacements will take place only in desired sites. Undesirable sites will not be replanted. One objective of this plan is to increase the stocking level in desirable sites. There will be little noticeable change in the village-wide canopy structure or in tree numbers over the next 15 years. Essentially, a gradual shifting to more desirable sites will be realized. When completely implemented, 100% of desirable sites will be occupied with healthy trees, while poorly located or declining trees will be minimal.

Planting Sites

East Aurora has a significant planting site advantage. Most street rights-of-way include space behind the sidewalk adequate for tree planting. Whenever possible, the primary planting site should be in this location. Trees will be able to develop without constraints of sidewalks or curbs, and will likely have significant longevity benefit. Few limits of eventual tree size must be considered.

The second category, planting sites defined between curb and sidewalk, are more restrictive sites. Minimum width for planting requires four feet, with the tree placed two feet from curb and sidewalk. Many trees maturing at short heights are not suitable for such sites due to spreading into sidewalk or street passageways. Sites less than eight feet between curb and sidewalk with overhead utilities should be planted with columnar trees directed to avoid wires.

The third planting site category is a combination of the above. Several blocks have primary planting sites identified behind the sidewalk. When the tree-lawn width is eight feet, or more, plantings should be made within the tree lawn in addition to plantings behind the sidewalks. Spacing is to be made considering tree location behind the sidewalk. Tree form must relate to limitations of each site.

Restricted sites exit in commercial areas and along Buffalo Road, Main and Olean Streets. Behind sidewalk plantings should be made whenever possible. In some commercial areas (e.g. Gray Street, Boise Alley) adequate planting space no longer exists. These sites should be considered on individual merit, and planted only if short-lived planting investments can be justified. All plantings in such sites are relatively high risk with short life expectancy.

Program Needs

The planting objective is to keep pace with tree decline and removals. This plan projects the assumption that at least 702 declining trees will be dead over a period of the next 15 years. Of those, 367 would be replaced in new locations (from site codes 8 and 10), with 335 replaced in or near the current site. Because so many EA trees are mature, a realistic rate of decline will approach .67% per year, or 10% over the fifteen-year life of the plan. A sustainable planting rate of 64 tree plantings per year will be necessary to keep pace. These numbers do not include special projects (e.g. NYDOT Main St).

East Aurora currently relies on two spring planting programs, the 'Share-the-Cost' and the Rotary Club projects to accomplish plantings at a rate of approximately 40 per year. Both programs should continue. Further analysis is necessary to determine if the 'Share-the-Cost' plantings are equally distributed. Projected annual tree planting costs for 64 trees is $9600. Six hundred twenty-three (623) open sites are available for planting. To plant trees at all sites would require an estimated $93,450.

This plan calls for the initiation of a fall planting program. Although it could be an extension of the Share-the-Cost program, it more likely should be a budgeted expense, filling the gap between accomplishments of the spring programs and the sustainability target of 64 trees per year. A fall planting program will coincide with the later efforts of the ongoing leaf pick-up, and may create some personnel adjustment or, more likely, contract planting. Numbers of trees planted may be variable, determined by the collective effectiveness of the spring planting programs. It would be desirable to accomplish all planting in the spring. A fall planting program would assure that plantings would keep pace with removals. Sites to be planted during the fall would be identified primarily based on desired equal distribution of new plantings (Ordinance 85-4 B).

Tree Species Diversity

Although East Aurora has diverse representation by many tree species, more than 50 species are present in numbers representing less than 1% each. Maples, including Sugar, Norway, Red and Silver represent 63% of all species.

This plan recommends greater diversity in all plantings. Maples should represent only 5-10% of new plantings. Many years will be required to achieve a reduction in the dominance of maples, but is best accomplished by reduced input, rather than a prolonged moratorium.

Increased use of ashes, oaks and various lesser-known species is recommended. Distribution of each species should be widely spread (e.g. Thornless Honeylocust trees may be appropriate in sites other than 'downtown'). Species selections for plantings are to be based on Street Tree Fact Sheets, edited by Henry D. Gerhold, Norman L. Lacasse, and Willet N. Wandell, Pennsylvania State University, 1993, or similar publication.

The ambient nature of the forest canopy in East Aurora has been affected historically by many factors. The result is a pleasant mix of trees of various species and sizes. This plan retains the diversity of this planting scheme. Very few newly developed streets currently display entire-street planting using same species and sizes. This theme will be retained during the duration of this plan.

Tree Maintenance

Although tree maintenance begins with planting and does not end until the tree is removed, this plan focuses on maintenance directly minimizing future problems or reducing current risk.

A significant problem exists with the number of trees with weakly joined co-dominant stems. Each is identified in the forest inventory. By the time the tree is large, corrective measures are either ineffective or invasive into other parts of the tree. Most treatments become costly. Treatment to remove co-dominant stems is accomplished best when the tree is small. This plan recommends the structural review of all trees within five years of planting. Weakest co-dominant stems are to be removed. This action will add years to tree longevity, as well as potentially saving many thousands of dollars in advanced maintenance and removal costs.

A second early maintenance activity relates to pruning in order to train a leader, or create a leader where one does not exist. This leader can be directed to grow away from wires while maintaining acceptable tree form. Early training often removes the need for expensive pruning when branches interfere with utilities. This early pruning is necessary around signs. Many smaller maturing trees can be trained to be slightly taller and less broad through corrective pruning.

A third maintenance problem relates to the timeliness of pruning for street clearance. This type of maintenance is done routinely as major street work is accomplished (e.g. repaving), often resulting in severe pruning with its related shock to the tree. The intensity of this pruning directly relates to lack of any pruning or delay of adequate maintenance clearing. Early maintenance to 'raise' the amount of clear trunk while reducing branches projecting into the street right-of-way is the best answer.

Recommendation is made to review street clearance policy. Is it possible to use trucks with lower overall raised-bed heights when working on certain residential streets? On State and County streets, clearance needs might be greater. Establishing a routine pruning schedule to raise trunk heights over several years, instead of severe one-time pruning at a time of great tree stress, will significantly benefit trees biologically.

Routine maintenance is considered highly desirable and would be conducted as funds become available. Routine maintenance would be defined as it relates to shaping or thinning tree crowns. Although desirable, this type of work must be postponed to accommodate highest priority specific tree problems. Whenever tree maintenance or removal work is done, neighboring trees should be reviewed. If appropriate, routine maintenance may be done at that time.

Priority maintenance applies to trees in decline containing large decaying areas or a dead co-dominant stem. In many instances of irreversible decline, the entire tree should be removed, but limited budgets require some method of prioritization. Whenever a significant risk exists, the tree should be treated at least to the extent of removing that risk. Within a few years the site may be revisited with the remainder of the tree removed. Five hundred sixteen (516) trees are classed as declining. Priority maintenance, including backlog, is estimated at $103,200 at current level. Over time, many such trees will move into categories of removal.

A maintenance problem closely related to, and affecting trees is sidewalk construction and repair. Indeed, this problem is very widespread. Evidence shown at the damaged root collars of many trees suggests at least two major efforts of sidewalk restoration work have taken place within the past 30 years. Street infrastructure must include pavement, curb, tree lawn, sidewalk, and trees.

Recommendation is made to review sidewalk policy. Each sidewalk construction project must include the evaluation of trees possibly affected. Firstly, some declining trees might be removed before construction, the sidewalk replaced, and new trees are planted as replacements. Secondly, trees with root collars into the sidewalk must be critically reviewed. If the tree is generally healthy, the root collar should be protected. One method would create a dish into the sidewalk to bypass the root collar. A second method would create a temporary ramp over the root collar. To create a safe, gentle rise, several sidewalk blocks might be removed and replaced with asphalt or elevated concrete. Although a temporary treatment, neither the sidewalk nor the tree increases risk liability.

Tree Removal

Highest risk and declining or dead trees have been identified by site in the 2001 inventory. At least 186 trees of various sizes are designated for immediate removal. Highest priority for removal within this group shall be large trees overshadowing a significant target (e.g. playground, house). Trees leaning or top-heavy to the street are considered lower priority inasmuch as they present lower risk. A significant number of these trees have been removed during the time between inventory completion and the development of this plan.

Cost of tree removal is approximately $500 per tree and stump, requiring $93,000 to fully address current removal needs. This plan suggests three years may be needed to accomplish this task. Over the life of the plan, removals will equal replacements. Beyond this 15-year plan, as healthy trees occupy desirable sites, plantings will equal or exceed the removal rate. This objective is possible prior to 15 years. Periodic evaluations may show an adjusted timetable is possible.

In recognition of the fact that some trees exist in sites that are considered poor, recommendation is made to review the Tree Ordinance section 85-8, Removal of Trees and Stumps. The following should be deleted: Trees removed by the Department of Public Works, or by natural causes shall be replaced on a one-for-one basis within one year.

General Considerations

Village Tree Board - In consideration of increased responsibility (e.g. tree planting and greater review considerations of tree-impacting projects), recommendation is made to increase the size of the Village Tree Board, currently with only five members. Efficient and timely attention to tree planting requests and project reviews are best served with the community divided into four units. With each unit assigned to two members and the Chairperson, nine board members may be needed.

Research and action recommendations from the Village Tree Board to DPW or the Office of the Mayor should become routine procedure for all projects with potential tree impact.

Recommendation is made that the Village Tree Board review its annual program activities, and submit an annual support budget request.

Certain community forestry circumstances may require services of an arborist or other tree care professional. Such activities may include updates of segments of the forest inventory, planting specifications, or establishing value appraisals of damaged trees. Technical assistance, provided on an occasional or scheduled basis, could add to the effectiveness of the Village Tree Board or the DPW. Recommendation is made to consider a budget item for such services either on a per diem or hourly rate.

Appendix - Definitions

Canopy structure - the extent of spread and density of tree branches for an individual tree, or the collective spread and density of a tree community, especially when viewed from above.

Co-dominant Stem - two or more leading stems divide but continue growing essentially as two trees nearly joined at the base. Bark may be trapped and crushed at the base, leading to decay and weakness. An upward-curving ridge between the stems at the point of union usually indicates strong stems not subject to bark trapping.

Community Forest Inventory - a scientific evaluation, completed in 2001, lists attributes of trees and sites. Inventory data is supported by mapping, and forms the baseline for planning and evaluations.

Leader - the focal point of growth at the end of a main stem results in a tree with a strong, single trunk. Lack of a strong leader results in co-dominant stems.

Risk - an expression of propensity of a tree to fail. As risk increases, the ability to retain the tree within a management system must decrease. Trees of highest risks may be termed 'hazard trees'.

Site - the physical location where a tree may exist, or may be planted. Site categories used in the inventory and plan include:
Site 1- a healthy tree exists in a good location; retain at this location.
Site 2- a declining tree exists in a good location; replace at this location when removed.
Site 3- a tree in irreversible decline, or dead tree exists in a good location; replace.
Site 4- a healthy tree on public property exists in good location, but with significant competition from a tree in another site on private property; retain planting only when competition gone.
Site 5- a healthy tree exists in poor site; do not replace when removed
Site 6- a declining tree exists in a poor location; do not replace when removed.
Site 7- a tree in irreversible decline, or dead exists in poor location; do not replace
Site 8- no tree exists in good location; plant as possible
Site 9- no tree exists in good location, but competition or other limitation forces delay of planting
Site 10- no tree exists in good location, but competition or other limitation is soon to be removed. Anticipate scheduling planting.

Stocking Level - expressed as a percentage of how many healthy trees in good locations exist in a given area compared to how many could exist under full theoretical conditions (100%).

Street - a unit of infrastructure including the paved right-of-way, curbs, tree lawns, sidewalks and trees.

Tree Lawn - also called utility strip, generally refers to space between sidewalk and curb. When neither sidewalk nor curb exists, a measurement is assigned relating to right-of-way width.