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

• Published in: PloS one Vol. 13; no. 1; p. e0191346
• Main Authors: Capdevila, Pol, Linares, Cristina, Aspillaga, Eneko, Riera, Joan Lluís, Hereu, Bernat
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 12.01.2018; Public Library of Science (PLoS)
• Subjects: Algae; Algues marines; Biodiversity; Biology and Life Sciences; Brown algae; Connectivity; Conservation of Natural Resources; Cystoseira; Distribution; Ecologia marina; Ecosystem; Ecosystems; Environmental management; Environmental research; Forests; Fucales; Laminariales; Lessonia; Marine algae; Marine ecology; Mediterranean Sea; Mediterrània (Mar); Phaeophyceae; Phaeophyceae - growth & development; Phaeophyceae - physiology; Physical Sciences; Plant Dispersal; Population; Research and Analysis Methods; Sargassum; Studies; Survival Analysis; Weibull distribution
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0191346

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.