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Oecologia
2010 Oct 01;1642:489-98. doi: 10.1007/s00442-010-1666-5.
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Triggers and maintenance of multiple shifts in the state of a natural community.
Rassweiler A
,
Schmitt RJ
,
Holbrook SJ
.
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Ecological communities can undergo sudden and dramatic shifts between alternative persistent community states. Both ecological prediction and natural resource management rely on understanding the mechanisms that trigger such shifts and maintain each state. Differentiating between potential mechanisms is difficult, however, because shifts are often recognized only in hindsight and many occur on such large spatial scales that manipulative experiments to test their causes are difficult or impossible. Here we use an approach that focuses first on identifying changes in environmental factors that could have triggered a given state change, and second on examining whether these changes were sustained (and thus potentially maintained the new state) or transitory (explaining the shift but not its persistence). We use this approach to evaluate a community shift in which a benthic marine species of filter feeding sea cucumber (Pachythyone rubra) suddenly came to dominate subtidal rocky reefs that had previously supported high abundances of macroalgae, persisted for more than a decade, then abruptly declined. We found that a sustained period without large wave events coincided with the shift to sea cucumber dominance, but that the sea cucumbers persisted even after the end of this low wave period, indicating that different mechanisms maintained the new community. Additionally, the period of sea cucumber dominance occurred when their predators were rare, and increases in the abundance of these predators coincided with the end of sea cucumber dominance. These results underscore the complex nature of regime shifts and illustrate that focusing separately on the causes and maintenance of state change can be a productive first step for analyzing these shifts in a range of systems.
Fig. 1. Percent cover of a the sea cucumber Pachythyone rubra and b macroalgae at sites on the north shore of Santa Cruz Island, California, USA from 1982 to 2007. Circles represent mean cover measured at individual sites (the average of two transects per site per year), dashed lines connect circles representing subsequent observations at the same site, horizontal bars represent average cover within each regime
Fig. 2. Potential environmental drivers of regime shifts (mean ± SE) estimated for each 5- to 6-year period: a density of predatory sea stars Pycnopodia helianthoides, b biomass of lobster (Panulirus interruptus), c percent cover of sea urchins, d percent cover of Macrocystis pyrifera, e concentration of dissolved inorganic nitrogen (DIN), f frequency of high wave events
Fig. 3. Cover of sea urchins from 1982 to 2008 at sites on the north shore of Santa Cruz Island. Circles represent mean percent cover measured at individual sites (n = 2 transects per site per year)
Fig. 4. Frequency of winter storms from 1982 to 2008, measured as the number of days per year when maximum significant wave height was greater then 3.25 m at the east Santa Barbara buoy
Fig. 5. Density of the predatory sea star P. helianthoides at sites on the north shore of Santa Cruz Island from 1982 to 2008. Circles represent mean density measured at individual sites (n = 2 transects per site per year)
Andersen,
Ecological thresholds and regime shifts: approaches to identification.
2009, Pubmed
Andersen,
Ecological thresholds and regime shifts: approaches to identification.
2009,
Pubmed
Arkema,
Direct and indirect effects of giant kelp determine benthic community structure and dynamics.
2009,
Pubmed
Chase,
Community assembly: when should history matter?
2003,
Pubmed
Chavez,
From anchovies to sardines and back: multidecadal change in the Pacific Ocean.
2003,
Pubmed
Connell,
Negative effects overpower the positive of kelp to exclude invertebrates from the understorey community.
2003,
Pubmed
Hsieh,
Distinguishing random environmental fluctuations from ecological catastrophes for the North Pacific Ocean.
2005,
Pubmed
Hughes,
Phase shifts, herbivory, and the resilience of coral reefs to climate change.
2007,
Pubmed
Leinaas,
Effects of removing sea urchins (Strongylocentrotus droebachiensis): Stability of the barren state and succession of kelp forest recovery in the east Atlantic.
1996,
Pubmed
,
Echinobase
Ling,
Overfishing reduces resilience of kelp beds to climate-driven catastrophic phase shift.
2009,
Pubmed
,
Echinobase
Miller,
Shading facilitates sessile invertebrate dominance in the rocky subtidal Gulf of Maine.
2008,
Pubmed
Petraitis,
Experimental confirmation of multiple community states in a marine ecosystem.
2009,
Pubmed
Reed,
Biomass rather than growth rate determines variation in net primary production by giant kelp.
2008,
Pubmed
Ryther,
Nitrogen, phosphorus, and eutrophication in the coastal marine environment.
1971,
Pubmed
Scheffer,
Catastrophic shifts in ecosystems.
2001,
Pubmed
Scheffer,
Floating plant dominance as a stable state.
2003,
Pubmed
Schmitt,
Contrasting effects of giant kelp on dynamics of surfperch populations.
1990,
Pubmed
Schmitt,
Seasonally fluctuating resources and temporal variability of interspecific competition.
1986,
Pubmed
Suding,
Alternative states and positive feedbacks in restoration ecology.
2004,
Pubmed
deYoung,
Regime shifts in marine ecosystems: detection, prediction and management.
2008,
Pubmed