Effective dispersal and density-dependence in mesophotic macroalgal forests: Insights from the Mediterranean species Cystoseira zosteroides

PLoS One. 2018 Jan 12;13(1):e0191346. doi: 10.1371/journal.pone.0191346. eCollection 2018.

Abstract

Dispersal and recruitment are fundamental processes for population recovery following disturbances in sessile species. While both processes are well understood for many terrestrial species, they still remain poorly resolved for some macroalgal species. Here we experimentally investigated the effective dispersal and recruit survival of a mesophotic Mediterranean fucoid, Cystoseira zosteroides. In three isolated populations, four sets of settlement collectors were placed at increasing distances (from 0 to 10 m) and different orientations (North, South, East and West). We observed that effective dispersal was restricted to populations' vicinity, with an average of 6.43 m and not further than 13.33 m, following a Weibull distribution. During their first year of life, survival was up to 50%, but it was lower underneath the adult canopy, suggesting a negative density-dependence. To put our results in a broader context we compared the effective dispersal of other fucoid and kelp species reported in the literature, which confirmed the low dispersal ability of brown algae, in particular for fucoids, with an effective dispersal of few meters. Given the importance of recruitment for the persistence and recovery of populations after disturbances, these results underline the vulnerability of C. zosteroides and other fucoid species to escalating threats.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Conservation of Natural Resources
  • Ecosystem
  • Forests*
  • Phaeophyceae / growth & development
  • Phaeophyceae / physiology*
  • Plant Dispersal*
  • Survival Analysis

Grants and funding

Funding was provided by the Spanish MINECO (CGL2012-32194) and the European Union’s Horizon 2020 research and innovation program under grant agreement No 689518 (MERCES). Support for this work was provided by an FI-DRG grant from the Secretaria d’Universitats i Recerca from the Economy and Knowledge Department of the Generalitat de Catalunya to Pol Capdevila and by a Ramon y Cajal research contract (RyC-2011-08134) to Cristina Linares. The authors are part of the Marine Biodiversity Conservation research group (2014SGR1297, www.medrecover.org) from Generalitat de Catalunya. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.