Competition Drives Clumpy Species Coexistence in Estuarine Phytoplankton.

Published in Scientific Reports, v. 3(1037)

Segura, A.M., Kruk, C., Calliari, D., García-Rodriguez, F., Conde, D., Widdicombe, C.E. and Fort, H.

Publication year 2013
  • Universidad de la Repu´blica, Facultad de Ciencias, Oceanography and Marine Ecology, Montevideo, Uruguay,
  • Functional Ecology of Aquatic Systems, Universidad de la Repu´blica, Uruguay
  • Universidad de la Repu´blica, Facultad de Ciencias, Institute of Ecology and Environmental Sciences, Limnology, Montevideo, Uruguay
  • Institute of Biological Research Clemente Estable - MEC, Laboratory of Ethology, Ecology and Evolution, Montevideo, Uruguay
  • Plymouth Marine Laboratory, Prospect Place, West Hoe, Plymouth PL1 3DH, UK
  • Universidad de la Repu´blica, Physics institute, Complex Systems Group, Montevideo, Uruguay


IAI Program


IAI Project CRN3070


Understanding the mechanisms that maintain biodiversity is a fundamental problem in ecology. Competition is thought to reduce diversity, but hundreds of microbial aquatic primary producers species coexist and compete for a few essential resources (e.g., nutrients and light). Here, we show that resource competition is a plausible mechanism for explaining clumpy distribution on individual species volume (a proxy for the niche) of estuarine phytoplankton communities ranging from North America to South America and Europe, supporting the Emergent Neutrality hypothesis. Furthermore, such a clumpy distribution was also observed throughout the Holocene in diatoms from a sediment core. A Lotka-Volterra competition model predicted position in the niche axis and functional affiliation of dominant species within and among clumps. Results support the coexistence of functionally equivalent species in ecosystems and indicate that resource competition may be a key process to shape the size structure of estuarine phytoplankton, which in turn drives ecosystem functioning.