Issue one addresses the social, political, economic and physical aspects of a community.
Sometime, no matter how much communities may want street trees, existing infrastructure discourages it. For this “downtown” area to accommodate street trees, something critical would need to be sacrificed…such as the entire downtown or the highway running through it!
Predicting the success of street tree landscapes is as much (if not more) about the social character of a neighborhood, the political climate of the community (is the city council “green”?) and the available funds for maintaining street trees as valued infrastructure. Aside from those restrictions, is there enough room for trees – above and below ground – and are the available planting sites even capable of supporting life? The time that you invest in answering and assessing these questions can save a lot of money and time later on.
Step one, determining the level of local support. A common mistake is to believe that the community has the same level of interest in street trees as you do…or perhaps they have the same lack of interest in street trees as you! Assuming that everyone thinks and values the same as the public works department or the city forester or the city planner is a gamble. The time invested in “inventorying” opinions and assessing the weight of those opinions is usually worth it.
Sometimes, a gauge of a community’s interests and attitudes can be determined by some basic behaviors. If the community has a comprehensive community plan, it should have a section on street trees, tree health, tree preservation…something that addresses the green half of the community infrastructure. Most community comprehensive plans were community inclusive and included a number of public brainstorming sessions, review sessions, focus groups, and community presentations. Information collected during those public response opportunities can reveal a lot about how a community values its natural resources, including its street trees.
Comprehensive Community Plans are public information and easy to obtain electronically.
Within most comprehensive plans, there will be appendices or sections that document public comments from public meetings, forums, focus groups or review meetings.
Take my word for it, no one mentioned a word about trees lining streets and sidewalks during these public sessions. This provides an opportunity to slowly expose the community to the potential benefits of street trees and how they can address issues such as “safe sidewalks between…and Gateway.”
Sometimes the necessary information just hasn’t been collected. Needs assessment surveys can be conducted to get specific, pertinent information, especially at the community level. These surveys can be conducted at neighborhood meetings, committee meetings, parks, schools or can be offered up on the community’s web site. Anything that can be done to get a better idea of how people feel about street trees and urban forests will be a good idea.
Visual surveys can be very revealing. Rather than asking people to respond to words or writing down wishes, ask them to react to different landscape photos. These are usually quick surveys, can be easily conducted during meetings or on the street interviews with individuals. People generally react to scenes better than descriptive phrases such as “Do you prefer a moderately canopied street or a heavily canopied street?”
Never underestimate the value of getting a clearer picture of how special interest groups view the street tree scene. Business owners that parallel streets and sidewalks are often very opinionated about the relative value of street and sidewalk trees. They are also often under-informed about the retail values that trees have been shown to return to the community. You won’t know any of this unless you ask them for their opinions.
After awhile, you’ll get a pretty good idea of the community’s attitudes and preferences towards street tree designs, different types of trees, and any “quality of life” benefits they may offer. With this knowledge, a campaign for either promoting the values of street trees or sustaining the interests in them should begin. With any community, the campaign starts with the constituency…those people that use, fund and benefit most from a well-planned and healthy streetscape. Visits to neighborhood functions such as block picnics, school functions such as Earth Day celebrations and short presentations to community service groups such as the Rotarians are all examples of time well-invested. Listen to the concerns and ideas of those public servants that will inherit the responsibilities for maintaining the streetscapes and keeping them healthy and safe. Finally, the ultimate decision-makers, who could range from the mayor to the city council to special interest commissions to the county or state highway departments. What are their concerns and questions? Keep them well-informed and the chances of a successful street tree master plan increase in kind.
The bottom line that we’re trying to promote is that street trees and their placements should benefit everyone, whether in a car, their home, on the sidewalks, or shopping.
Street tree designs should multi-task. Canopies for comfort, visual access for safety, and a climate that people are drawn to for recreation or commerce.
Simple illustrations such as this show the benefits of even simple street tree plans: a more human scale for shoppers, more comfort and protection from the hot sun and a feeling of a successful/affluent shopping area.
The next question: even if the community supports the idea of a street tree master plan and understands the benefits of trees, will they be willing to fund it? A lot of this willingness to fund a sustainable program depends on how you present the picture: Is it inclusive? Is it complete? Is it accurate?
Beyond the design phase of a street tree master plan, there are a lot of layers to fund which can also be promoted as opportunities for in-kind contributions, grant opportunities and other contributions.
One of the more insidious and unpredictable expenses associated with street tree landscapes is the extra cost associated with conducting business as usual without damaging the trees. Installing and maintaining infrastructure, plowing snow and keeping streets and sewers clean of debris are probably the last things people think of when they’re envisioning a verdant transportation corridor intersecting their town.
The green infrastructure of a community has two “facts-of-life” principles that are shared with the constructed infrastructure: 1. It requires maintenance to remain useful, and 2. Deferred maintenance doesn’t work. At some level, maintenance of a street landscape is an annual cost, even though individual trees may only be pruned every 5-10 years. And like other infrastructure, trees need to be replaced for one reason or another.
Presenting the cost:benefit analysis of street trees like this is a proposal doomed for failure. Each one of those benefit bullets should be detailed and expanded to illustrate how the benefits far outweigh the costs, especially with a well-planned street tree landscape.
One of the most effective message that appeals to a large segment of a community’s population is one that puts money in their pockets.
Without adequate space or physical properties that can support safe and healthy trees, a master plan for street tree design will be difficult to attain for an entire community.
The entrance to a lovely little community, but a scene that discourages street tree master plans! No curbs/gutters so no defined “tree lawn” area. Lots of overhead utility wires posing potential tree/utility conflicts. The entrance to this community is a state highway, so there are inherent restrictions on the placement of trees near the road in light of driver safety issues. No sidewalks. Steep drainage ditches. And finally, a good measure of rural forest remnants.
A street scene such as this presents some challenges to a comprehensive and cohesive street tree design. The boulevard widths are sufficient to support some trees, especially those that stay under 40 feet at maturity. Unfortunately on one side of the street, overhead utility lines…low, overhead utility lines will always compromise the tree selection and health of the trees as well as the overall balance of the design. The ginkgos under the power line to the left were not meant to be shaped as wings of an eagle.
A good example of a transportation corridor that is not (currently) street tree receptive. On the right, overhead power lines will restrict the size of plant materials used. On the left, remnant forests replace any space or need for street trees. Leave it alone. Although the criteria for wide and straight roads has been met, there’s no value in street tree plantings for this corridor.
This scene on the other hand offer many more possibilities for an effective street tree landscape. Relatively gentle topography, good sight lines, utilities that are well above the ultimate height of most street trees and generous soil volumes in both the median strip to the left and the boulevard to the right.
This is a relatively “ideal” community for providing the physical elements that support an effective street tree landscape. Boulevards and medians that are at least 6-8 feet wide, gentle topography and streets that are moderately curved.
Close to an ideal boulevard situation for a healthy street tree population. Boulevards 10 feet wide and more are boulevards that can support healthy, safe street trees. Most importantly, there is enough space for the cyclical replacement or improvement of buried utilities without the predictable damage to root systems.
Actually, this is less the fault of a narrow boulevard and more the fault of a tree species that has an abnormally high TDR (trunk:diameter ratio). This mature cottonwood has a trunk flare diameter of almost twice the diameter of the trunk above the flare. A great tree for open spaces but not so great for more size-restrictive boulevards. Obviously, the tree has affected the curb on this street and the damage that will happen to the tree as the curb is repaired will be too much for the tree to safely bear.
Although the photo to the left seems to show the same old mistakes being repeated – too little root space for big trees – the photo to the right shows the construction of vaults of soil that were constructed under the pavement before the trees were planted. Little surface area, but lots of rooting area.
This area is not quite so ideal. The trees are largely failing before they reach maturity on the commercial side of the street, primarily due to inadequate soil volumes. The trees live for a few years before environmental stress forces them into a rapid decline to death. An excellent example of how rooting volume impacts the success of a street tree landscape can be seen in the photo to the right, and the trees on the right hand side of the street. There, with more generous rooting volumes that support the trees, normal growth and health is obvious and the trees are actually green assets rather than brown liabilities.
This boulevard will never support a healthy street tree population. Less than 24 inches wide, susceptible to deicing salt residue in the soil…recipe for arboreal failure.
Finally, does the community even allow boulevard or street trees to be planted and maintained? If the restriction is an ordinance, it is a long and difficult process to change this legal document. If it’s part of the community’s policy or practice, this is a much more manageable situation, one that can more easily be amended with the cooperation of the community.
This series of “lessons” is based on the manual “The Road to a Thoughtful Street Tree Master Plan,” authored by Ken Simons and Gary Johnson. Funding for the production of the manual and this companion lesson series was provided by the Minnesota Local Road Research Board, the U.S. Forest Service/Northeastern Area, and the University of Minnesota/Department of Forest Resources.
Issue 1: Is Your Community Street Tree Receptive?
<ul><li>Is there local support? </li></ul><ul><li>Is funding adequate? </li></ul><ul><li>Is the landscape conducive to street trees? </li></ul><ul><li>Can boulevards and R.O.W.s support life? </li></ul><ul><li>Are street trees permitted? </li></ul>
<ul><li>EXISTING CLUES </li></ul><ul><li>Comprehensive Community Plan </li></ul><ul><li>Tree Ordinance or Policy </li></ul><ul><li>Tree Board </li></ul><ul><li>Tree City USA </li></ul><ul><li>City Forester </li></ul><ul><li>Tree Budget </li></ul>
<ul><li>LOOKING FOR CLUES </li></ul><ul><li>Surveys </li></ul><ul><li>Neighborhood Meetings </li></ul><ul><li>Council/Committee Meetings </li></ul><ul><li>Focus Groups </li></ul>
<ul><li>Bottom-Up Campaign </li></ul><ul><ul><li>Neighborhood/Block Groups </li></ul></ul><ul><ul><li>Schools </li></ul></ul><ul><ul><li>Businesses </li></ul></ul><ul><ul><li>Special Interest Groups </li></ul></ul><ul><li>Listen to City Employees </li></ul><ul><ul><li>Engineers and Planners </li></ul></ul><ul><ul><li>Law Enforcement </li></ul></ul><ul><li>Listen to Decision-Makers </li></ul>
<ul><li>Purchasing new trees </li></ul><ul><li>Planting new trees </li></ul><ul><li>Maintaining new trees </li></ul><ul><ul><li>Health </li></ul></ul><ul><ul><li>Safety </li></ul></ul><ul><li>Working around trees </li></ul><ul><ul><li>Parking </li></ul></ul><ul><ul><li>Construction </li></ul></ul><ul><li>Replacing trees </li></ul>
<ul><li>Costs </li></ul><ul><ul><li>Purchase Price </li></ul></ul><ul><ul><li>Installation </li></ul></ul><ul><ul><li>Watering and Pruning </li></ul></ul><ul><ul><li>Health Maintenance </li></ul></ul><ul><ul><li>Safety Maintenance </li></ul></ul><ul><ul><li>Sidewalk, Curb, Sewer Repair </li></ul></ul><ul><ul><li>Utility Maintenance </li></ul></ul><ul><ul><li>Removal </li></ul></ul><ul><li>Benefits </li></ul><ul><ul><li>Quality of Life </li></ul></ul><ul><ul><li>Environmental </li></ul></ul><ul><ul><li>Economic </li></ul></ul>
“… in Milwaukee the values of homes located directly on streets with landscaped boulevards are higher…A 2000 study found that they were worth about $1,600 more than those farther away, despite greater levels of traffic.” Wisconsin Academy Review, Winter 2005.
<ul><li>Curbs? </li></ul><ul><li>Urban Woodland? </li></ul><ul><li>Overhead Utilities? </li></ul><ul><li>Winding or Straight? </li></ul><ul><li>Broad or Narrow Right-of-Way? </li></ul>
<ul><li>Minimum width of 8 feet </li></ul><ul><li>Free of overhead utilities </li></ul><ul><li>Minimum of 300 cu. ft. of root volume </li></ul><ul><li>Minimal deicing salt </li></ul>