Wherever you live...You Live in a Watershed
Watershed protection and the urban forest
Urban forests are essential for a cleaner, healthier Chesapeake Bay. The trees in our backyards, along the streets, and in city parks all help to prevent erosion and filter pollutants from rainwater runoff, resulting in cleaner water flowing to our rivers and the Bay.
When we speak of the "urban forest" we simply mean all trees and shrubs growing in populated areas. The urban forest includes trees in people's yards, along roadsides, in community parks, cemeteries, and commercial districts. An urban forest can be made up of just a few trees, or thousands of trees.
It might be difficult to understand that trees and the city can coexist, but a surprising number of trees do grow in urban areas. Although trees were cut and land cleared to make way for cities, many trees were saved or protected during construction and others were planted to replace trees that were lost.
Watershed protection in the urban environment is one of the most important functions of the urban forest. Often, when new houses, shopping centers, highways or industrial complexes are built, acres and acres of forests are removed. As bare land is exposed, more soil is washed away, surface temperatures increase and harsh eyesores are created. When trees are part of the landscape, their canopies interrupt and slow the rainfall and lessens its impact on the soil. The roots of the trees help to hold the soil together, and absorb and use water and excess nutrients that would otherwise pollute a nearby waterway. If everyone plants trees in his own watershed, a valuable contribution to the recovery and productivity of the Chesapeake Bay has been made.
A WATERSHED is an area where all the water, whether stream flow or ground water, flows to a common waterway. A watershed can be as small as the roof of a house where water drains into the gutter and downspout and from there to the yard. The water then flows to a storm drain or a stream and eventually, in Maryland, to the Bay.
A watershed can be as large as the entire Chesapeake Bay drainage basin, which covers 64,000 square miles. All precipitation falling on this six-state region eventually drains into the Chesapeake Bay . Actually, the Chesapeake Bay watershed is made up of millions of small watersheds and everyone living in these watersheds has an impact on the Bay. As rainwater flows over the ground, it carries with it oil and grime from parking lots, soil from construction sites, fertilizers from lawns, and chemicals from industrial discharges. The pollutants enter one of fifty major tributaries, and ultimately find their way to the Bay itself. Millions of people live in the watershed, and everyone's actions have an effect on the health of the Bay.
We did not always have the problem of having to protect our urban watersheds. When the first settlers first arrived in Maryland in the early 1600's, forests covered almost all the land. The water was clean, erosion was minimal, and animals flourished. As more colonists arrived, forests were cut to furnish lumber for homes, to clear homesites and crop fields, and to burn as fuel. Erosion increased and the decline of the Bay began.
We know that urban forests help protect our watersheds; they supply many other benefits as well. Trees properly located around homes and other buildings provide cooling summer shade, offer protection from chilling winter winds, and maximize energy gains from winter sunlight. Heating bills can be reduced by 30 percent, while cooling costs can be reduced by as much as 50 percent. Trees and shrubs can replace fences and walls by functioning as visual screens and sound barriers. Trees, with their spring blossoms and their fall foliage colors, add much to the beauty and tranquillity of a community. Trees soften harsh city landscapes by interrupting the vistas of steel and concrete. Birds and small animals find food and cover in the urban forest and often add to our enjoyment of being able to spend time "in the woods" without leaving the city. Through photosynthesis, trees convert carbon dioxide into oxygen, helping to control the greenhouse effect which leads to global warming. All these benefits to urban forests produce another attractive advantage - the increase in the real estate value of a home site or other property. The presence of trees has been known to add up to 20 percent to property values.
Benefits and Values A properly managed urban forest:
Few other community resources offer such a varied and extensive benefit package.
- improves water quality by reducing sediment and nutrient loading into tributaries of the Chesapeake Bay and the Bay itself;
- provides a suitable habitat for wildlife;
- reduces the atmospheric level of carbon dioxide, the primary culprit in the "greenhouse effect", and gives off oxygen for us to breathe;
- lowers energy costs - strategically placed trees can reduce summer cooling costs by up to 50 percent;
- when used as wind breaks, can reduce heating costs by as much as 30 percent;
- is aesthetically pleasing, creating an enjoyable environment in which to live and work;
- increases property values 5 to 20 percent, depending on such factors as size, number, species, and lot location of trees;
We are losing the benefits of the urban forest at an alarming rate as our forests disappear because of development, pollution, insects, disease and sadly, because of neglect. This loss of forest land is robbing us of the many good things they provide.
Land clearing for both residential and commercial development continues at a rapid pace all over the State of Maryland. Each year thousands of acres of forest land are removed to satisfy our insatiable appetite for progress - more houses, more shopping centers, more industrial parks and more roads. The modest tree planting efforts that accompany this development cannot begin to offset fully the loss of our forest resource. In addition to losing the trees and their many benefits we also lose valuable wildlife habitat, decrease the opportunities for outdoor recreation, degrade the aesthetic value of our surroundings and increase soil erosion and sediment and nutrient loading in the Chesapeake Bay.
As our urban areas continue to expand - they now cover 69 million acres nationwide and are increasing at a rate of 1.3 million acres per year - it becomes increasingly important that we strive to maintain and manage existing trees as well as initiate programs to plant new trees.
To assist communities, towns and developers in the proper management of this valuable resource, the MARYLAND DEPARTMENT OF NATURAL RESOURCES FOREST SERVICE has an Urban and Community Forestry Program. Maryland has a long history of urban tree management that dates back to 1914 and the establishment of the Roadside Tree Law, the oldest such law in the nation. In addition to enforcing this law, the Urban and Community Forestry program also provides a number of other services, free of charge, including the following:
Tree Preservation and Protection Around Development Areas: This program aims to preserve and protect trees, where possible, around development areas. Urban foresters are eager to talk with developers in the early planning stages, make recommendations about which trees to save and how to save them, and work cooperatively with developers to ensure the success and profitability of the project. In some instances, it might be impossible to save existing trees; in this case the urban foresters make recommendations about which trees to plant for replacement. The urban forester also conducts seminars for builders/developers to assist them with methods and techniques of tree protection around development areas.
Street Tree Inventories/Urban Forest Management Plan: In towns and communities with an established tree resource, street tree inventories are conducted to determine the condition of the resource. Information collected in the inventory includes tree location, species, size, condition and management needs (trimming, fertilization, etc.) The inventory is the first step in developing a comprehensive urban forest management plan. The management plan uses information contained in the inventory to make recommendations and put in place a plan of action. Urban foresters are available to assist towns and communities, regardless of size, in all phases of the inventory/management plan process and the implementation phase. Funding for such urban forestry projects is often available.
Conclusion Urban forests are as old as cities themselves, and have been providing benefits such as clean water, clean air, havens for wildlife, cooling shade, and beauty for ages. As forests of all types disappear, the importance of urban forests in Maryland has increased dramatically.
Urban forests will play an important role in protecting our watersheds and especially the Chesapeake Bay . As a developer, community member or homeowner, you have an opportunity to retain urban forest land, preserve your urban forest or initiate urban forest restoration by seeking the free assistance of the MARYLAND DEPARTMENT OF NATURAL RESOURCES FOREST SERVICE.
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