Modelling Ecosystem Functions and Properties at Different Tme and Spatial Scales in Shallow Coastal Lagoons: An Application of the LOICZ Biogeochemical Model

The LOICZ biogeochemical model (LBM) was applied at different temporal and spatial scales in 17 Italian lagoons of the LaguNet network. The LBM was first revised taking into account benthic vegetation and sedimentary fluxes in the Sacca di Goro lagoon. This application was then compared with the classical LBM approach at different time scales. The reliability of the LBM application to the 17 Italian lagoons was tested through the comparison with the global LOICZ database. Among the LOICZ sites, we selected a pool of shallow coastal systems which are comparable for depth and size with the Italian sites. The nutrient loads of the Italian sites can be considered relatively low, in particular for DIP. Median values of ¿DIP and ¿DIN of the LaguNet sites were comparable with the LOICZ database, but the positive and negative extreme values were one order of magnitude lower. Overall, the LBM applications to the Italian sites gave good quality budgets of shallow systems subjected to relatively low nutrient inputs and with a wide range of primary producer communities, spanning seagrass, macroalgae and phytoplankton. The use of the C:N:P stoichiometry of the different primary producer group allowed a series of relationships to be identified between nutrient loads and ecosystem functions, which cannot be detected with the classical LBM approach. The latter, which generally uses the Redfield stoichiometry, seems suitable mainly in deep and turbid systems where benthic vegetation plays a negligible role. To some extent, the LBM application at monthly and seasonal time scales, as shown for the Sacca di Goro lagoon, can simulate the internal variability which depends upon the life cycle of the dominant primary producer components. Therefore, the modified LBM seems also capable to represent the wide range of trophic conditions which usually occur within and among shallow coastal systems.

GIORDANI G.;  AUSTONI Martina;  ZALDIVAR COMENGES Jose';  SWANEY Dennis;  VIAROLI P.; 

2008-03-03

ACADEMIC PRESS LTD ELSEVIER SCIENCE LTD

JRC40918

0272-7714,   

https://publications.jrc.ec.europa.eu/repository/handle/JRC40918,   

10.1016/j.ecss.2007.09.017,