Before we can fully understand how to promote urban forestry through the planning process we must define the “urban forest” concept. From a planner's perspective, the urban forest encompasses the total plant environment in the community with tree plantings as the primary elements. The urban forest is a people-oriented forest designed to enhance the quality of life aesthetically, ecologically, and economically. The urban forest consists of public plantings, such as street trees, roadside plantings, parkways, neighborhood parks, traffic median plantings, public parking lot landscaping, and landscape easements. Some have classified this as the “community” forest. The urban forest also includes plantings on private residential, commercial, and industrial properties. Some have referred to this as the " domestic" or “commercial” forest. Simply defined, the urban forest is the overall “green” environment in the community, whether it be public or private plantings.
Key factors
In order to encourage the development of the urban forest and ensure its survival there are certain key factors that we must strive for:
There must be commitment on the part of the local governmental agency and its staff. The local governmental agency must set the pace and serve as an example to the private sector in the community.
Information must be communicated to the general public regarding the value of the urban forest in order to realize full support in the community.
Teamwork is essential between local agency departments, especially those related to engineering, planning, building, recreation, parks, street trees, and public works. All disciplines must work together to achieve common goals and objectives for a healthier, more beautiful environment.
Enforcement of regulations and design standards for new development is necessary in order to attain long-term results.
Santa Maria, California: A Case Study
In Santa Maria the urban forest is less complex than other communities. The City was developed on a treeless floodplain without the benefit of natural woodlands or vegetation. However, the City has made great efforts to promote and develop its urban forest through various means within a relatively short period of time. Some methods would be considered quite traditional and others rather innovative.
Traditional methods
In the late 1950’s, a street tree ordinance was adopted that outlined the policies, procedures, and enforcement capabilities concerning street trees in the City of Santa Maria. This led to the establishment of a formal street tree program in 1960. The current inventory under the program is 16,843 street trees. With a current population of 50,000 plus, the City still has a way to go to achieve its goal of one street tree per capita.
In 1967, the City launched an aggressive downtown tree planting program. Street trees were planted in all commercial areas in the sidewalk. Rather than the traditional forty foot on center, the trees were planted in clusters using the deep-well planting method unique to Santa Maria. The trees were planted eighteen inches below grade in a 36¼″ ×42¼″ well with concrete walls. A pre-cast concrete aggregate lid fits into a lip on top of the well so that it is flush with the sidewalk. This method prevails in all commercial and industrial areas where street trees are planted in the sidewalk area. After nineteen years of experience with the deep well method, these deep well plantings have caused little or no damage to surrounding sidewalks and street improvements.
In residential areas, the earlier street trees were planted as surface plantings in a typical four-footwide parkway. In recent years, the traditional parkway system has been abandoned in favor of a reverse parkway or a ten-foot-wide tree-planting easement behind the sidewalk, which is now installed directly adjacent to the curb. This allows for easier maintenance of the ground cover and watering of the street tree by the property owner.
Street trees are also planted along arterial streets that border residential subdivisions. A block wall, which is used to mitigate noise impacts from the street traffic, usually separates the street and sidewalk from the backyards of the interior lots. While several wall pocket designs were experimented with, none was particularly successful. The City is now requiring eight-foot-wide sidewalks to accommodate clusters of deep well plantings adjacent to the curb and still provide adequate space for pedestrian access.
All street trees, as well as deficient public improvements, are required to be installed by the subdivider or developer, in accordance with City specifications, as a condition of approval for new development.
The City has also developed and maintains a considerable amount of plantings in parkways and traffic medians. Quite notably, the City maintains a landscaped, setback area around the periphery of a regional shopping mall, a senior citizen housing project, and a low-income family housing project in a downtown redevelopment area. The City's current effort is to replant existing traffic medians, as well as new ones, with drought-tolerant plant materials.
The City maintains a park system of approximately one hundred sixty-one acres with several new parks now under development. The City assesses a residential development tax to each new dwelling unit built in the City. A park land acquisition fee in the amount of $424 per dwelling unit is collected at the time of subdivision. This fee is collected in lieu of the subdivider dedicating land for park purposes. In addition, a fee in the amount of $442 per dwelling unit is collected at the time of building permit issuance for the development and improvement of park land. These assessments are reviewed and established annually by the City Council.
As part of a downtown commercial revitalization project, that was a joint public/private venture, the City developed public parking lots in the downtown area in exchange for sixty percent agreement from the property owners to facelift and rehabilitate their buildings. The parking lot development was funded through the Federal Community Development Block Grant Program. These parking lots are people-oriented and include extensive landscaping, seating areas, and attractive walkway paving.
Innovative planning
In 1976, the City adopted the Entrada Specific Plan which provides specific development standards for architectural treatment, parking lot development, and landscape design for those properties adjacent to the major entrance-ways into the City. This plan was due to the development of the Central City and Central Plaza urban renewal projects which generated interest in developing adjacent properties for commercial and office uses, the plan attempts to create a unified design and identity for the Central business district.
In 1980, the City formed the South Miller Street and South College Drive Landscape Maintenance District pursuant to the Landscaping and Lighting Act of 1972. In addition, design standards were adopted as a specific plan establishing City policy regarding the treatment of walls, sidewalks, street landscaping, drainage facilities, and traffic medians along approximately two miles of Miller Street and three miles of College Drive.
The intent of the plan is to provide a uniform design theme for both street corridors that will serve as a buffer between the street and adjacent land uses. The planting concept is to create an informal woodland setting that will provide an attractive view for pedestrians and motorists.
The plan applies to both residential and commercial properties. The property owners are required, at such time as they wish to develop their property, to provide a landscape and pedestrian access easement and install improvements within the easement area. The maintenance of the improvements along residential property and retardation basins is the responsibility of the City with funds generated by tax assessment through the maintenance district established at the time of development. The maintenance of landscaping along commercial property is the obligation of the property owners.
On September 3, 1985, the City adopted an “Urban Forest” section as part of the Environmental Resource Management Element of the General Plan. The Conservation and Open Space Elements are two of several General Plan Elements mandated by the State of California. Santa Maria has elected to integrate the Conservation, Open Space, and Scenic Highway Elements into one document known as the ERME. With adoption of the Urban Forest section, the future of Santa Maria's urban forest is protected and encouraged as a valuable natural and cultural resource.
For quite a number of years the City's Planning Department has required the submittal and approval of landscape plans as a condition of approval for use permit, zone change, or development plan applications related to the development of private property. Ongoing landscape maintenance is also a condition of approval requiring follow-up field inspections by City staff. The on-site landscaping, irrigation, street trees, and other zoning requirements must be installed prior to the granting of occupancy and approval for utility service for a new building. This procedure requires cooperation between the Planning, Building, Public Works, and Recreation & Parks Departments.
In December 1985, the City Council adopted Uniform Landscape Guidelines that prescribe the policies and regulations for landscape development in all zoning districts in the City with the exception of R-1 (Single-Family Residential). The guidelines have been adopted as a separate chapter of the Zoning Ordinance which provides the enforcement capability needed in terms of design and development. Some of the highlights of the guidelines are:
For the purpose of buffering and screening between two adjoining incompatible land uses, the common yard areas should include not less than a ten foot minimum planted area.
In commercial and manufacturing districts, not less than 15% of the site area shall be planted area.
In multi-family residential districts, not less than 20% of the site area shall be planted area.
Water conservation shall be considered in the selection of plant material and design of the irrigation system. In parking areas, a minimum of one 15 gallon tree per six parking spaces must be provided.
In parking areas, a minimum of 200 square feet of planter area is required per every twenty parking spaces.
Concerning building wall treatment, a minimum of one 15 gallon tree is required per thirty linear feet of building wall.
Preservation of existing trees in excess of six inches in diameter is required unless the trees present a hazard to the health, safety, and general welfare of the public or cannot be reasonably accommodated by the proposed development. If approved for removal, the trees must be replaced with box sized plantings.
In closing, the following is a quote from a favorite modern day philosopher, Andy Rooney of 60 Minutes, that sums up the need for promoting and protecting the urban forest in our communities. He unhappily relates the story of how his neighbor has cut down a perfectly healthy hundred-year-old maple tree. He says, I liked the tree our neighbor cut down even though it wasn't really mine. I say “really mine” because I think of old trees in a neighborhood as common assets that are not so much owned by anyone but shared by all.
If we are to enjoy a healthy, attractive environment in our communities we must work together to ensure that these “common assets” are provided for, nurtured, and protected so that they may, in fact, be shared by all for generations to come.
- © 1987, International Society of Arboriculture. All rights reserved.