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Dettmann, E. Turnover Time. Chapter n/a, Reference Module in Earth Systems and Environmental Sciences. Elsevier Online, New York, NY, , 1-7, (2013).
Ecosystems contain energy and materials such as carbon, nitrogen, phosphorus, and water, and are open to their flow-through. Turnover time refers to the amount of time required for replacement by flow-through of the energy or substance of interest contained in the system, and is calculated as the ratio of the system’s content of that substance to its flow-through rate. The system is often assumed to be in equilibrium (inflow rate equal to outflow rate), although the use of turnover time in system analysis is also useful when this is not the case. Turnover time is useful in conceptualizing the significance and interrelationships of fluxes, pool sizes, and replacement times of essential materials and contaminants in ecological systems and in understanding the dynamics of pool sizes in systems that are not in equilibrium. The concept of turnover, usually as a turnover rate (the inverse of the turnover time), is also used to analyze rates of appearance or extinction of species within localized ecosystems such as islands or patches of forest or other ecological units, and in quantifying harvest and replacement rates of individuals within the adult class of harvested populations, for example, marine fisheries.
The impact of this publication will be to make information on the concept of turnover time available to a broader audience, including students and water quality and ecological researchers.
Record Details:Record Type: DOCUMENT (BOOK CHAPTER)
Organization:U.S. ENVIRONMENTAL PROTECTION AGENCY
OFFICE OF RESEARCH AND DEVELOPMENT
NATIONAL HEALTH AND ENVIRONMENTAL EFFECTS RESEARCH LAB
ATLANTIC ECOLOGY DIVISION
WATERSHED DIAGNOSTICS BRANCH