Efectes d’un incendi sobre el metabolisme de la llacuna del Ter Vell

Abstract

In this study, we have described the ecosystem metabolism of Ter Vell, a coastal lagoon located between Torroella de Montgrí and l'Estartit which suffered a wildfire at the end of 2021. We have estimated metabolic rates by applying a Bayesian model to data collected over a period of 9 months. Our objective was to assess the impact of the fire on the metabolism of the lagoon by examining the metabolic rates of production and respiration which are described as good indicators of metabolism in these ecosystems. We also wanted to analyze the seasonal metabolic changes by quantifying the concentration of dissolved oxygen and the ecological state of Ter Vell by comparing the metabolism of the year of the wildfire with that of other previous years. We have observed how during summer months, as light intensity and temperature increase, both production (GPP) and respiration (ER) reach higher values than the rest of the seasons. However, after the fire has occurred, there are also peaks in the GPP. Temperature shows a low and non-significant relationship along production. Comparing GPP with the same rate without the effects of light intensity

(GPPmax) we observe that during wildfire it reaches values as high as in summer. GPPmax shows how the wildfire affects the production of the lagoon and therefore its metabolism, although not directly due to the influence of other factors. A similar pattern is also observed in the saturation of dissolved oxygen, which undergoes greater oscillations with higher values during summer months and after the wildfire occurred, reaching the same conclusion. Finally, we compared the PR quotient and GPP with data from 2 previous years, where the meteorological conditions were completely different from those of our study to assessthe ecological state of Ter Vell. PR quotient was identified as the best quality indicator of Ter Vell due to the variations in between the different periods analysed