Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
6296017 | Ecological Modelling | 2016 | 6 Pages |
Abstract
An ecosystem may abruptly switch into a contrasting stable state at a critical threshold under the effect of external drivers, a phenomenon called regime shifts. However, drivers are generally assumed to be independent of system states, and thus associated driver-system state interaction is largely ignored when studying regime shifts. With dryland ecosystems as study objective, this study used a mean field model with drift potential as driver to investigate the influences of driver-system state interaction on dynamics of regime shifts. Our results showed following three aspects of influences of the interaction. (1) The interaction pushed the equilibria of regime shifts as a whole into higher drift potential, especially for the forward path. Under annual rainfall of 150Â mm, 300Â mm and 500Â mm, tipping points of the upper branches moved forward 140Â VU, 151Â VU and 152Â VU with strength of the interaction of 200Â VU relative to these with strength of the interaction of 0Â VU, respectively. (2) The interaction could expand the bi-stability region of regime shifts in driver space, e.g., from 125Â VU (annual rainfall of 150Â mm), 181Â VU (annual rainfall of 300Â mm) and 209Â VU (annual rainfall of 500Â mm) under the interaction of 0Â VU up to 145Â VU, 257Â VU and 290Â VU under the interaction of 200Â VU, respectively. (3) The interaction might repel ecosystems away from the middle range of system states. These results suggest that the driver-system state interaction should be considered in the studies of regime shifts, and thus to better understand, predict and combat desertification in practice.
Related Topics
Life Sciences
Agricultural and Biological Sciences
Ecology, Evolution, Behavior and Systematics
Authors
Ning Chen, Xin-ping Wang,