From ecophysiology to ecosystem restoration of Posidonia oceanica meadows – a mechanistic modelling journey

In the restoration of complex ecosystems, the reliance on heuristic models, based on collections of failures and successes, hinders the prediction of system evolution, the estimation of the associated uncertainties and the adoption of timely adaptive measures. Mechanistic approaches can overcome these limitations by allowing the scaling up from individuals to ecosystems, but their reliance on clear understanding and mathematical description of species ecophysiology still limits their wide adoption. This is the case even of extensively studied taxa, such as Posidonia oceanica, where the lack of comprehensive strategies for data acquisition resulted in a striking shortage of data useful for model development. With the aim to move from heuristic to mechanistic approaches to the ecological restoration of P. oceanica meadows, the research focused on developing an individual-based model of meadow evolution where Dynamic Energy Budget theory describes plant ecophysiology and purposely acquired data are used for model development and parametrization. Specifically, data on carbon allocation in leaves, rhizomes and roots along a depth gradient, together with data on morphology and photosynthetic pigments are used to functionally describe and parametrize the environment-driven variations in the fluxes of photosynthetic carbon acquisition, maintenance and translocation. Such a circular strategy, where model’s requirements guide the acquisition of data embedded in clear theoretical processes, in turn allowing model refinement, jointly ensures a better understanding of species ecological plasticity, the effectiveness of data acquisition and the successfulness of ecosystem restoration.