Urban tree crown health assessment system: a tool for communities and citizen foresters
Trees are important assets to urban communities. In addition to the aesthetic values that urban trees provide, they also aid in such things as erosion control, pollution removal, and rainfall interception. The urban environment, however, can often produce stresses to these trees. Soil compaction, limited root growth, and groundwater contamination are just a few of the factors that can influence tree health. In order to preserve the health of urban trees, an effective monitoring regime is necessary. Communities often seek the help of citizen foresters (concerned volunteers from the community) to aid in data collections of this type. Unfortunately, these volunteers have limited tools and resources that an arborist or other tree professional might have. An effective urban tree monitoring regime is one that uses tools available to the average citizen and allows for minimal knowledge of urban forestry. The U.S. Forest Service Southern Research Station in Blacksburg, Virginia is in the process of constructing a web-based tool that will allow urban foresters, citizen foresters, and other concerned individuals to assess the health of urban trees using digital photographs. The assessment will be based on tree crown characteristics, which serve as good indicators of overall tree health. The tool will allow individuals to upload digital images of urban trees, have those images processed using crown analysis software, and return to the user the results of the analysis. The software developed by the Forest Service will provide estimates of tree length, crown diameter, live crown ratio, crown volume, crown density, and foliage transparency. The database driven website will allow users to monitor individual tree crown characteristics over time and assist in diagnosing declining tree health.