Ecologische regime shift

In the Resilience theory, ecosystems do not have one equilibrium state, but possess more than one stable state, also called regimes, or basins/domains of attraction. Regime shifts are transitions between alternative stable states (Scheffer 2001). These shifts occur when a threshold has been passed and the feedback systems within the ecosystem changes into a different direction, towards a different stable state (Folke et al., 2004 and the references therein). The idea of alternative stable states was already introduced by Holling in 1973, but it took a few decades before the theory gained momentum. Folke et al. (2004) reviewed the evidence of regime shifts in terrestrial and aquatic ecosystems, and indicated that the regime shifts are more likely to increase when human pressure decreases resilience. Changes from one alternative stable state into another may be sudden and dramatic (e.g. the change of a clear shallow lake into a turbid lake), or gradual (e.g. the shift from a grass dominated into a shrub dominated rangeland). A change into another stable state implies a change in structure of and processes within the ecosystem in question. And this, in its turn, may lead to a change in ecosystem services generated (Folke 2004). Pressures that may lead to regime shifts are, amongst other things, removal of functional diversity, or even removal of whole functional groups removal of trophic levels, increase in frequency, rate or duration of disturbances, climate change, etc. and/or a combination of these factors (Folke et al., 2004).

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Holling, C.S., Resilience and Stability of Ecological Systems, Annual Review of Ecology and Systematics, 1973 4: 1-23 Folke , C. et al., Regime shifts, Resilience and Biodiversity in Ecosystem Management, Annual Review of Ecol. Evol. Syst. 2004. 35:557–81 Scheffer, M. et al., Catastrophic shifts in ecosystems, 2001 Nature 413:591–96

Ecologische regime shift

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