Urban. Ecological Processes
Change is continuous in the American city.
The means through which the distribution of Has this pattern peen true of most major cities in the United States? Communitypeople and activities change are known as ecological processes. To understand them we must begin with the natural area, a collection of people and activities which are drawn together in mutual interdependence within a limited area. The district of flophouses and cheap hotels, cheap restaurants, pawn shops, pornography shops, taverns, and missions, all catering to the needs of low-income homeless” men and women, is an example of a natural area. Other natural areas include the department-store section (formerly; most have .now moved to the shopping centers), theentertainment area, the communities of recent immigrants, the rooming-house district, the college students’ residential area, tile warehouse district, and many others. Natural areas , are unpanned. They arise from choice of individuals. Persons having similar needs and preferences are drawn together into an area where these are most ‘easily fulfilled, and this creates a natural area. The neighborhood, unlike the natural area, may be either planned or unplanned. A neighborhood is an area where people neighbor,and not all areas are neighborhoods. Th is very little neighboring in some areas, such as the rooming-house district, and more neighboring in the ethnic communities and family-residence areas. Some urban neighborhoodsare consciously planned, with housing, communication, shopping, and recreation facilities deliberately arranged to encourage neighboring. More often the neighborhood is an unplanned product of people’s need for social relations. Neighboring is greatest in family-residence areas where people face common problems of child rearing and crabgrass fighting. Neighborhoods and natural areas are constantly being formed, dissolved,
and relocated through the urban ecological processes of concentration, centralization, decentralization, segregation, , and . Concentration is the tendency for people and activities to gather where conditions are favorable. It produces the growth of cities. Centralization is the clustering together of the economic and service functions within the city. People come together to work, to play, to shop; then they return to other areas to
live. The shopping district; the factory district, and the entertainment district are empty of .people for a part of each day or night. The central business district is a prime example of centralization. Decentralization is the tendency of people and organizations to desert the center of the city for outlying areas where congestion is less and land values are lower . The automobile and motor truck and electric power have greatly encouraged residential, commercial, and industrial decentralization tendency which greatly complicates the task of anyone who seeks to diagram the pattern
of the city. Segregation refers to the concentration of certain types of people or activities within a particular area. The “Gold Coast,” the ghetto,
and the produce market areas are examples, along with the hotel and banking districts, the theajer distric, and “used-car row.” Segregation may be either voluntary or involuntary’. Most immigrant groups voluntarily
segrega ted the nselves, for life was more-comfortable that way. The ethnic neighborhood in the large American cities was partly voluntary and partly involuntary [Wirth, 1928]. The ghetto is an example of involuntary segregation, as low income, shortages of moderately priced housing, and a variety-of threats and intimidations combine to confine most blacks to certain residential areas [Abrams, 1955; Grier and Grier, 1960; Foley, 1973]. Invasion takes place when a new kind of people, organization, or activity enters an area. Residential area’> may be invaded by business, a business area may be invaded by a new kind of business residents or a different class level or ethnic group may move into aresidential area. Generally the invasion is of a higher-status area by a lower-status group or activity. This direction of invasion is a normal outcome of the process of city growth and of aging. A once-exclusive residential area of homes which are no longer fashionable is invaded by people a class level below the present occupants. A generation later the same area may be invaded by persons still another class level lower, or by blacks or other ethnics, or by secondhand stores and other business houses. Occasionally the direction
is reversed. As stated earlier, there are areas where dilapidated housing is being renovated or rebuilt into an upper-class residential area (gentrification). Many upper-income people have fled to the suburbs because attractive new housing is located there. Many would like to remain close to the city’s center if satisfactory housing were available. Some areas have therefore traveled the complete cycle of upper-class residence to slum to upper-class residence. In all likelihood, the cycle will now be repeated . Succession is the final stage, in which the changeover to new people or activities becomes completed. The area may remain’ in a disorganized and chaotic state or may become well organized around it!’. new residents or land use. This invasion process is continuously in operation in every American city. The processes of growth and aging make it inevitable. It is a costly process in terms of human frustration and economic waste–but no one has suggested a practical alternative. Zoning is not an alternative-it is simply a technique for making invasion and succession more deliberate and orderly and for protecting vested interests in the process [Ballcock, 1966;Taylor, 1980, pp. 76-77]. It is through these ecological processes that the city continues to change. City planners today are trying to control and direct the processes in order to make them less wasteful and painful.