Abstract
Biological invasions are a major component of the ongoing change in biotic communities. In this project, we will explore the trophic interactions between three introduced seaweed species and their native herbivores in order to evaluate the importance of these interactions for invasion success and on the effects of invading species on ecosystem processes. Firstly, we will test the hypothesis that plants from invading populations allocate relatively more resources to defence and relatively less to growth compared to plants from the native range, by growing plants from native and introduced populations in a common-garden experiment. Secondly, we will use mesocosm experiments and coupled field experiments to explore the consequences of such a difference for two important ecosystem processes: community-level primary production and the transfer of energy to the next trophic level. Since invasions often result in an increase in local biodiversity, the experiments are constructed to test also the more general hypothesis that community diversity affects production and consumption. We expect that the project will contribute to the development of tools for predicting invasion success and ecosystem effects of invasions, apart from elucidating the effect of three introduced macroalgae on the Swedish coastal ecosystem.
Sweden