These days, there is much discussion about how cities can and should be planned. Since the dawn of the Industrial Revolution, economic development has been a primary driver for how U.S. cities have grown. While cities have been reshaped to maximize the efficiency of manufacturing and transportation industries, these patterns of sprawl have created urban centers relatively devoid of trees.
Among modern city planning there is a stronger focus on the ways cities can incorporate methods of economic development which minimize negative environmental impacts. These methods, often referred to as "greening", are being adopted in cities across the United States at various levels of intensity and with various levels of success. One particular method, spurred by the emerging study of Urban Ecology, is assessing the density of tree canopy cover in a city, or Urban Tree Canopy (UTC).
As the map below shows, UTC density varies in different areas of the continent - even varying dramatically within individual states.
UTC is now being measured at many scales, with various levels of agency, and through many forms of creative collaboration. Within the United States, national tree canopy data is collected through the U.S.Geological Survey and as part of the National Land Cover Database. Individual states also collect data on tree cover, often through offices such as the Indiana Department of Natural Resources Forestry Division, which completed a statewide study in 2011. This study found that Indiana had an estimated statewide average Urban Tree Canopy Cover of 24.58%. It also subdivided the state, estimated the UTC of those nine regions as well as over Indiana 100 cities.
As trees in urban environments have been increasingly studied, they have been shown to provide many benefits to their cities and the people living therein. This blog series will take a closer look at the benefits provided by improving UTC and some of the strategies being used to categorize and increase tree canopy density.
Sources:
Davey Resource Group. (2011). Assessing and Addressing Indiana Urban Tree Canopy (Rep.). Retrieved from https://www.in.gov/dnr/forestry/files/fo-FinalINUTCSummaryRep.pdf Prepared for Indiana Department of Natural Resources Division of Forestry Pamela Loucks