Comparing ecosystem processes among rivers, lagoons and sea: an experiment in aquatic ecosystems of Corfù island (Greece)

In aquatic ecosystems, the decomposition of organic detritus represents one of the most important ecosystem functions, which support the detritus-based food webs. The rate of decomposition is usually calculated to recognized the process, being a synthetic measure that take in to account both abiotic and biotic factors. Decomposition rates have been also applied to evaluate the ecological status in terms of ecological functionality. Even if the researches on detritus decomposition have been carried out in all aquatic ecosystems including rivers, transitional waters and sea, no comparative study regarding the variation of decomposition rates among these ecosystems is available, to date. Here, we compare decomposition rates from rivers, lagoons and sea. Five sampling sites were fixed in each of the 3 of the most important rivers and in lagoons of Corfù island (Greece); other 5 sampling sites were fixed in the sea around the island. Twelve leaf packs containing 3 g of dried Phragmites australis leaves were submerged in April 2014 and retrieved after 30 days. Abiotic parameters were recorded in both sampling dates. Macroinvertebrates were removed from the retrieved leaf packs, counted, identified at lower taxonomic level and weighted. Leaf pack decomposition rates were calculated, and their variability was compared within each aquatic ecosystem, within each ecosystem typology (river, lagoon, sea) and among ecosystem typology. The results are going to be presented on the poster.