CALCIUM AS AN INDICATOR OF URBAN ENVIRONMENTAL INFLUENCES

Urban land-use change can affect biogeochemical cycles through altered disturbance regimes, landscape management practices (e.g., irrigation and fertilization), built structures, altered environments (heat island effect, pollution, introduction of non-native species, loss of native species), and the importation of various materials. Calcium (Ca) is ubiquitous in urban areas because it is an important component of many building materials (e.g., cement and gypsum). We present case studies from the metropolitan areas of New York and Baltimore, and data from the literature that show the redistribution of Ca in urban landscapes (e.g., atmosphere, soil, and water) and suggest that this accumulation of Ca in soil and sediments can serve as a useful indicator of urban environmental influences on urban ecosystems. Moreover, we discuss the biological and geochemical importance of Ca accumulation in urban landscapes.