Contrasting effects of ocean warming on different components of plantherbivore interactions

Este artículo contiene 11 páginas, 6 figuras, 1 tabla.There is increasing uncertainty of how marine ecosystems will respond to rising temperatures. While studies have focused on the impacts of warming on individual species, knowledge of how species interactions are likely to respond is scant. The strength of even simple two-species interactions is influenced by several interacting mechanisms, each potentially changing with temperature. We used controlled experiments to assess how plantherbivore interactions respond to temperature for three structural dominant macrophytes in the Mediterranean and their principal sea urchin herbivore. Increasing temperature differentially influenced plant-specific growth, sea urchin growth and metabolism, consumption rates and herbivore preferences, but not movement behaviour. Evaluating these empirical observations against conceptual models of plant-herbivore performance, it appears likely that while the strength of herbivory may increase for the tested macroalga, for the two dominant seagrasses, the interaction strength may remain relatively unchanged or even weaken as temperatures rise. These results show a clear set of winners and losers in the warming Mediterranean as the complex factors driving species interactions change.The Spanish Ministry of Science and Innovation funded this research (projects CMT2010-22273- C02-01-02 and CMT2013-48027-C03-R) and supported JB (scholarship BES-2011-043630). The Spanish National Research Council supported RA's visitorship (CSIC-201330E062). TS was supported by an Australian Government Endeavour Fellowship. JFP acknowledges financial support from the Welsh Government and Higher Education Funding Council for Wales through the Sȇr Cymru National Research Network for Low Carbon, Energy and Environment. Support to FT was provided by the Ramón y Cajal Programme (RYC-2011-08572).Peer reviewe