Correspondence trials between fresh and marine waters: opportunities from the Enveurope-Long Term Ecological Research network

The importance of agreed indicators or parameter sets based on common conceptual background is recognized and requested to promote an efficient governance of ecosystems. Long-term data appear fundamental to select the more easily measurable and most predictive indicators. In addition it is advocated the development of uniform methodologies and calibration systems based on which historical data might be elaborated and new data collected in a consistent way. Freshwater and marine ecosystems may represent a good starting point to test the efficacy of some selected indicators in the ecosystem comparison approach. Several attempts have been made using chlorophyll data to analyse the evolution of water quality. Indeed chlorophyll proved to be effective in describing the trophic state of both fresh and marine waters. Also optical properties can be compared and used to scale up ecosystem process to a global perspective, as for example by remote sensing. Although to date little used, a rising tool may be provided by the stoichiometric approach. The assessment of stoichiometric changes in the biomass of organisms seems also promising in view of the comparison between aquatic and terrestrial ecosystems. In this work we compare, as a case study from Italy, freshwater and marine ecosystems, included in the project EnvEurope and in E-LTER. We aim basically at investigating the opportunities of the trans-ecodomain approach, for: i) evaluating and understanding ecosystem changes through time, identifying common local and regional/global causes; ii) assessing the possibility to integrate and scaling up the environmental information; iii) developing joint scientific hypotheses.