Oecologia

, Volume 168, Issue 4, pp 1079–1090

Spatial dynamics of benthic competition on coral reefs

Community ecology - Methods Paper

DOI: 10.1007/s00442-011-2156-0

Cite this article as:
Sandin, S.A. & McNamara, D.E. Oecologia (2012) 168: 1079. doi:10.1007/s00442-011-2156-0

Abstract

The community structure of sedentary organisms is largely controlled by the outcome of direct competition for space. Understanding factors defining competitive outcomes among neighbors is thus critical for predicting large-scale changes, such as transitions to alternate states within coral reefs. Using a spatially explicit model, we explored the importance of variation in two spatial properties in benthic dynamics on coral reefs: (1) patterns of herbivory are spatially distinct between fishes and sea urchins and (2) there is wide variation in the areal extent into which different coral species can expand. We reveal that the size-specific, competitive asymmetry of corals versus fleshy algae highlights the significance of spatial patterning of herbivory and of coral growth. Spatial dynamics that alter the demographic importance of coral recruitment and maturation have profound effects on the emergent structure of the reef benthic community. Spatially constrained herbivory (as by sea urchins) is more effective than spatially unconstrained herbivory (as by many fish) at opening space for the time needed for corals to settle and to recruit to the adult population. Further, spatially unconstrained coral growth (as by many branching coral species) reduces the number of recruitment events needed to fill a habitat with coral relative to more spatially constrained growth (as by many massive species). Our model predicts that widespread mortality of branching corals (e.g., Acropora spp) and herbivorous sea urchins (particularly Diadema antillarum) in the Caribbean has greatly reduced the potential for restoration across the region.

Keywords

Competition–colonizationSpatial constraintsHerbivorySize-specificityCellular automata

Supplementary material

442_2011_2156_MOESM1_ESM.doc (19 kb)
Supplementary material 1 (DOC 18 kb)

Copyright information

© Springer-Verlag 2011

Authors and Affiliations

  1. 1.Center for Marine Biodiversity and ConservationScripps Institution of OceanographyLa JollaUSA
  2. 2.Department of Physics and Physical Oceanography/Center for Marine ScienceUniversity of North Carolina, WilmingtonWilmingtonUSA