The Central Arizona-Phoenix Long-Term Ecological Research (CAP LTER) project is one of 26 LTER sites funded by the National Science Foundation. Launched in 1997 along with the Baltimore Ecosystem Study (BES) as the first urban LTER sites, CAP LTER has been instrumental in establishing urban ecology as a recognized and important area of ecological inquiry. The central research question that guides the project's research is: How do the services provided by evolving urban ecosystems affect human outcomes and behavior, and how does human action (responses) alter patterns of ecosystem structure and function, and ultimately, urban sustainability, in a dynamic environment? With an emphasis on ecosystem services, sustainability, and change, we ask three subsidiary research questions corresponding to different portions of our conceptual framework:
In addressing these questions, CAP LTER researchers focus on a broad geographic area in central Arizona and metropolitan Phoenix where two major desert tributaries of the Colorado River, the Salt and Gila Rivers, converge. The edges of this geographic focal area remain fluid to allow scientists to investigate urban influences beyond these boundaries, conduct comparative work, and examine issues related to the growing megapolitan area between the greater Phoenix and Tucson areas. CAP LTER's conceptual framework illustrates the major press and pulse events that drive changes in the geophysical and socio-cultural-economic templates. Land-use change, land-cover change, and legacies are important foci for CAP research. Other changes to the desert ecosystem through housing and urban infrastructure development, the construction and management of urban landscapes, and alterations to the hydrologic system are also important press events. CAP addresses these issues through a series of long-term monitoring and experimentation efforts as well as other projects to elucidate patterns and processes in the urban socioecosystem.