Experimental Evidence for Spatial Self-Organization and Its Emergent Effects in Mussel Bed Ecosystems

Abstract

Spatial self-organization is the main theoretical explanation for the global occurrence of regular or otherwise coherent spatial patterns in ecosystems. Using mussel beds as a model ecosystem, we provide an experimental demonstration of spatial self-organization. Under homogeneous laboratory conditions, mussels developed regular patterns, similar to those in the field. An individual-based model derived from our experiments showed that interactions between individuals explained the observed patterns. Furthermore, a field study showed that pattern formation affected ecosystem-level processes in terms of improved growth and resistance to wave action. Our results imply that spatial self-organization is an important determinant of the structure and functioning of ecosystems, and it needs to be considered in their conservation.

Delay driven spatiotemporal chaos in single species population dynamics models

“…Self-organised patterns are noted in beds of blue mussel populations, Mytilus edulis, on intertidal ats with signi cant variability in mussel density observed on larger scales of meters, but with no apparent within-cluster di erence. It is suggested that the interaction between individual mussels is the only underlying mechanism of such pattern formation (Gascoigne et al 2005, van de Koppel et al 2008). In the quest of revealing irregular spatial distributions, the most intuitive starting point would be amongst cyclic populations, as they tend to be regulated by highly nonlinear interactions (Bjørnstad et al 2002).…”

Why mussels stick together: spatial self-organization affects the evolution of cooperation

“…In these systems, the number of potentially cooperating neighbours depends on the spatial scale and distribution pattern of the population. In many systems, the spatial pattern results from the active movement of organisms (Theraulaz et al 2003;Jeanson et al 2005;van de Koppel et al 2008;de Jager et al 2011;Hemelrijk and Hildenbrandt 2012). Accordingly, the movement strategies of these organisms can indirectly affect the number of neighbours an individual will encounter.…”

“…First, we investigate how the aggregation strategy of mussels affects the spatial pattern and, in particular, the number of neighbours available for cooperation. Aggregation in mussels typically leads to the formation of a spatial pattern consisting of regularly spaced strings and clumps (van de Koppel et al 2005. With an individual-based model (IBM), we investigate how the number of neighbours a mussel experiences is related to this self-organized pattern.…”

“…Systems as diverse as mussel beds, coral reefs, marsh tussocks, tidal wetlands, peat lands, arid ecosystems, and ribbon forests are highly structured in space due to the interplay of local facilitation and long-range inhibition (Klausmeier 1999;Mistr and Bercovici 2003;Rietkerk et al 2004a, b;van de Koppel et al 2005van de Koppel et al , 2008van de Koppel and Crain 2006;Rietkerk and Van de Koppel 2008;Eppinga et al 2009). In these systems, the number of potentially cooperating neighbours depends on the spatial scale and distribution pattern of the population.…”

“…Mussels self-organize into large-scale labyrinth-like patterns (van de Koppel et al 2005. They use their foot to aggregate into a group of conspecifics after wide dispersion by the currents during the larval stage (Geesteranus 1942).…”