Population dynamics of the brown alga Himanthalia elongata under harvesting pressure

Doriane Stagnol (1) , Renaud Michel (1) , Dominique Davoult (1)

1 EFEB - Ecogéochimie et Fonctionnement des Ecosystèmes Benthiques

Through experimental harvesting, followed by a 12-month monitoring of demographic attributes, we tested the influence of harvesting on the population dynamics of Himanthalia elongata. We further explore the data to test the hypothesis that the canopy would exert a negative effect on the other developmental stages (intraspecific competition) throughout the recovery cycle of the population. This showed that the H. elongata canopy plays a marked seasonal role not by precluding the presence of other developmental stages but by delaying or preventing their growth and development. The removal of the canopy facilitates the transition from one developmental stage to another, eventually permitting a fast recovery of size structure in the population. This study allows us to integrate population dynamics and intraspecific relationships in our understanding of macroalgal recovery patterns.

Mots clés: intraspecific relationships; intertidal; management; population dynamics; restoration

Domaines: Biodiversité et Ecologie

Doriane Stagnol, Renaud Michel, Dominique Davoult. Population dynamics of the brown alga Himanthalia elongata under harvesting pressure. Estuarine, Coastal and Shelf Science, 2016, 174, pp.65-70. ⟨10.1016/j.ecss.2016.03.014⟩. ⟨hal-01297341⟩