Modelling biomass and nutrient dynamics in eelgrass (Zostera marina L.): applications to the Lagoon of Venice (Italy) and Oresund (Denmark)

A model to describe the seasonal cycle of eelgrass biomass and to quantify the presence of Zostera mai ina in coastal areas, depending upon environmental conditions, is presented in this paper. This model is characterised by a simple structure and it can easily be coupled with other models considering other compartments of the ecosystem. The simulation of internal nutrient dynamics, peculiar to this model, allows a more comprehensive description of eelgrass physiology. The first goal of this study is the understanding of the growth cycle of Zostera mai ina in the Lagoon of Venice and the comparison with other environmental situations. Secondly, this work aims to provide a tool to study the competition between marine phanerogams and floating macroalgae in the Lagoon of Venice. The model is calibrated with a set of experimental data collected ad hoc in the Lagoon of Venice and quantitatively tested with another set of data reported in literature for a Danish shallow water area. A sensitivity analysis was carried out, the most sensitive parameter, accounting for shoots respiration, was used to tune the model for both environmental situations. A statistical analysis of the results is finally shown. (C) 1997 Elsevier Science B.V.