Propagule pressure and functional diversity interactive effects on a macroalgal invasion process

• Published in: Marine ecology. Progress series (Halstenbek) Vol. 471; pp. 51 - 60
• Main Authors: Vaz-Pinto, Fátima, Olabarria, Celia, Arenas, Francisco
• Format: Journal Article
• Language: English
• Published: Oldendorf Inter-Research 19-12-2012
• Subjects: Animal and plant ecology; Animal, plant and microbial ecology; Applied ecology; Biological and medical sciences; Biological invasions; Colonization; Colonizing ability; Conservation, protection and management of environment and wildlife; Ecological invasion; Functional diversity; Functional groups; Fundamental and applied biological sciences. Psychology; General aspects; Marine ecology; Modeling; Mortality; Parks, reserves, wildlife conservation. Endangered species: population survey and restocking; Photosynthetically active radiation; Sea water ecosystems; Synecology; Marine environment; Sargassum muticum; Biological invasion; Propagule; Macroalgae; Marine alga; Propagule pressure; Resources; Environmental monitoring; Invasion success; Functional diversity; Environmental protection
• ISSN: 0171-8630; 1616-1599
• DOI: 10.3354/meps10024

Invasive species are considered an increasing global threat to marine ecosystems. Understanding which factors can accelerate or reduce invasion success is one of the main goals of invasion ecology. The present study investigated the interactive effects of propagule pressure and native functional diversity on the invasion success of the invasive algaSargassum muticum(Yendo) Fensholt over a 1 yr invasion process (i.e. settlement, recruitment and colonisation). The invasibility of macroalgal assemblages with different functional diversity was assessed under high and low propagule pressure. Synthetic assemblages resembling natural marine macroalgal assemblages were built and used as model systems. Recruitment discs were used to record early settlement in the assemblages. Recruitment and colonisation success were monitored in the field 2 and 10 mo after exposure to propagule rain in the laboratory. The availability of resources (space and photosynthetically active radiation [PAR]) was also monitored for each assemblage and used as predictive variables in the analyses. The effects of propagule pressure and functional diversity varied among the invasion stages. Space availability did not play a significant role in the recruitment success of the invader. However, PAR was a key resource in its invasion success. Overall, the invasion success ofS. muticumwas influenced differently by different traits of the recipient assemblages. Hence, invasion success may be better explained by the interaction of environmental factors that co-vary with species diversity and identity at different invasion stages.