Searching for tipping points: are there thresholds in stream ecosystem function?

De Mendoza CONICET

Revisión a fecha de 19:05 19 mar 2012; Fcampon (Discusión | contribuciones)
(dif) ← Revisión anterior | Revisión actual (dif) | Revisión siguiente → (dif)

Abstract: An ecological threshold is defined as a condition beyond which there is an abrupt change in a quality or property of an ecosystem. Rather than responding to gradual changes in a smooth way, ecosystems may respond with sudden, discontinuous shifts to alternative states. This “tipping point” concept has considerable appeal to resource managers who desire specific management targets, but some argue that the value of thresholds is illusory and may lack widespread applicability. Nevertheless, rapid, human-induced changes are altering ecosystems and anticipating the rate of change is key to preserving and protecting natural systems. To take just one example, water is being extracted from streams in growing quantities worldwide to meet basic human needs, even as it becomes increasingly clear that water removal changes the way streams look, act and function. Abrupt phase shifts may occur when decreasing flow causes stream to fragment, which can lead to further physical and ecological changes within isolated segments. Alteration of stream flow is among the many serious threats to the ecological sustainability of streams and their associated communities, but we are only beginning to understand what causes a stream to “tip”. This talk is an exploration of some of these causes.

Herramientas personales