Macro- and mesoherbivores prefer native seaweeds over the invasive brown seaweed Sargassum muticum : a potential regulat
- PDF / 594,612 Bytes
- 11 Pages / 595 x 791 pts Page_size
- 25 Downloads / 173 Views
ORIGINAL PAPER
Macro- and mesoherbivores prefer native seaweeds over the invasive brown seaweed Sargassum muticum: a potential regulating role on invasions Carla A. Monteiro · Aschwin H. Engelen · Rui O. P. Santos
Received: 28 April 2009 / Accepted: 28 July 2009 / Published online: 19 August 2009 © Springer-Verlag 2009
Abstract Herbivory has a strong impact on algal distribution, abundance and community structure and may inXuence the establishment and spread of introduced seaweed species. In this study, we assess the potential regulating role of herbivory on one of the most invasive brown seaweeds: Sargassum muticum. Multiple choice feeding experiments were conducted with 13 native seaweeds, S. muticum and 5 herbivore species from the Northwest, Southwest and South of Portugal. S. muticum was always the least or among the least preferred seaweeds and attained one of the highest growth rates of the tested seaweeds, with and without herbivores. The addition of herbivores increased the number of cases by 40% in which the invader had higher growth rates. Our results suggest that low grazing pressure on S. muticum by the recipient herbivore community may give the invader a competitive advantage over at least part of the native seaweed community, thereby contributing to the invasiveness of S. muticum along the Portuguese coast.
Communicated by S. D. Connell. Carla A. Monteiro and Aschwin H. Engelen have equal authorship. C. A. Monteiro · A. H. Engelen (&) · R. O. P. Santos ALGAE-Marine Plant Ecology Research Group, CCMAR, CIMAR-Laboratório Associado, Universidade do Algarve, FCMA, Campus de Gambelas, 8005-139 Faro, Portugal e-mail: [email protected] C. A. Monteiro e-mail: [email protected] R. O. P. Santos e-mail: [email protected]
Introduction Species invasions threaten the integrity of natural ecosystems and annually cause billions of dollars of economic losses worldwide (Mack et al. 2000). Human activity, by providing the required dispersal vectors and increasing the susceptibility of natural communities, has a pronounced inXuence on the number of introductions and consequently on the number of successful invasions. Biological invasions are a global problem. Because introduced species can cause such harm, and because the processes by which introduced species succeed address fundamental ecological theory, much recent attention has been devoted to understanding invasion biology (Mack et al. 2000; Torchin and Mitchell 2004). The success of non-indigenous species is dependent on a complex combination of (1) intrinsic characteristics of nonindigenous species (see Engelen and Santos 2009), which often have broad ecological requirements and tolerance (e.g. large geographical range), r-selected life histories (Baker 1974), association with disturbed or anthropogenic habitats (Sakai et al. 2001) in combination with propagule pressure (Britton-Simmons and Abbott 2008) and origins from large continents with diverse biotas and (2) characteristics of recipient ecosystems, in particular, the biological environment, e.g. the absence
Data Loading...
