The main goal of my research is to understand the changes in the trophic and size structure and the composition of the phytoplankton community under the grazer resistance vs. competitive ability trade-off. The results found until now have shown me the importance of the second trait of this ratio, competitive ability, classically knows as bottom up control. Competition based on the ratio surface/volume, or in the r-K dichotomy, nutrients storage ability and alternative nutritional pathways as mixotrophy confer an amazing plasticity to the phytoplankton community, which allow its adaptation to almost any environment. In contrast, top-down control seems to be a secondary factor in environments where nutrients are scarce and only becomes a major factor when nutrient availability is insured.
In Mediterranean coastal lagoons, one of the most important factors on the regulation of nutrient availability is the hydrologic pattern. The combination of the frequency (circulation-confinement gradient) and the origin of the water inputs (salt-freshwater gradient) lead to a particular environment with its particular phytoplankton community. In this sense, the trophic strategy dominating the phytoplankton community will depend on the proportion of inorganic:organic nutrient availability.
The last decade several studies have reported the consequences of climatic change on coastal ecosystems, such as the increase of mean water temperature, increase of sea level and flooded inland surface, and changes in runoff frequency and intensity. The degree of these changes is difficult to evaluate, however it is certain that these changes in hydrological pattern will modify trophic relationships in aquatic ecosystems, at least at the level of the microbial loop. Thus, learning the processes by which the organisms of the microbial loop respond to the hydrological and climatic changes could help us understand the progressive transformation of the planktonic community.