Modelling growth of Ruppia cirrhosa

The main objectives of this work were to synthesise information on the auto ecology of Ruppia cirrhosa Petagna (Grande) in a mathematical model and to use the model to simulate its growth, production and harvest. Model paramet ers were allowed to vary as a result of acclimation, following experimental data reported in the literature. Biomass data from Santo Andre lagoon (SW Portugal) were used to calibrate the model. Validation was carried out with independent data sets from Santo Andre lagoon and from Tancada lagoon (NE Spain). Model simulations show a reasonable agreement with observed data wi th a similar biomass temporal dynamics and peaks. Self-shading appears to b e an important self-regulating mechanism of biomass growth and production. The results obtained predict an annual net primary production of 361 g DW m (-2)well within the estimates based on harvesting techniques (295-589 g DW m(-2)). Model results suggest that controlled harvesting of macrophyte biom ass may be carried out without affecting macrophyte real net production, th rough the reduction of Light limitation under the plant canopy. (C) 2000 El sevier Science B.V. All rights reserved.