Sammanfattning

Habitat characteristics, predation and competition are known to interactively drive population dynamics. Highly complex habitats, for example, may reduce predation and competition, allowing more individuals living together in a certain area. However, the strength and direction of such interactions can differ strongly and are context dependent. Furthermore, as habitat characteristics are rapidly changing due to anthropogenic impacts, it becomes increasingly important to understand such interactions. Here, we studied the interactive effects of predation and competition on common cockle (Cerastoderma edule) recruitment, growth and survival under different habitat characteristics in the Wadden Sea, one of the world's largest intertidal ecosystems. In a predator-exclosure experiment, we manipulated cockle densities (100 vs. 1000 individuals m(-2)) and shorebird predation at two sites differing in habitat characteristics, namely at the wake of a blue mussel bed (Mytilus edulis) and at an adjacent sandy site. We found that recruitment was higher in the mussel-modified habitat, most likely due to reduction of hydrodynamic stress. Although bird predation strongly reduced recruit density, the combined effects still yielded more recruitment at the vicinity of the mussel bed compared to the sandy area. Furthermore, we found that high cockle densities combined with high densities of other potential prey (i.e. mussels) at the mussel-modified site, mitigated predation effects for adult cockles. Apart from these positive effects on adults, mussel-modified habitat reduced cockle growth, most likely by reducing hydrodynamics in the wake of the mussel bed and by increasing inter-specific competition for food. Our study experimentally underpins the importance of habitat characteristics, competition and predation in interactively structuring intertidal communities.

Nyckelord

Predation; Intraspecific and interspecific competition; Ecosystem engineer; Population responses; Mytilus edulis; Cerastoderma edule; Shorebirds; Wadden Sea

Publicerad i

Journal of Experimental Marine Biology and Ecology
2020, Volym: 523, artikelnummer: 151267

SLU författare

• Donadi, Serena

  • Institutionen för akvatiska resurser (SLU Aqua), Sveriges lantbruksuniversitet
    

Globala målen

SDG14 Bevara och nyttja haven och de marina resurserna på ett hållbart sätt för en hållbar utveckling


UKÄ forskningsämne

Ekologi


Publikationens identifierare

DOI: https://doi.org/10.1016/j.jembe.2019.151267

Permanent länk till denna sida (URI)

https://res.slu.se/id/publ/102712