0000000000131156
AUTHOR
Gérard Pergent
Nouvelles connaissances sur les herbiers tigrés de Méditerranée.
International audience; Les herbiers à Posidonia oceanica présentent plusieurs types morpho-structuraux généralement conditionnés par les conditions de milieu (profondeur, hydrodynamisme, substrat, pente, turbidité, sédimentation). Du fait de leur rareté, deux structures particulières, les récifs barrière et les herbiers tigrés, sont considérées depuis une vingtaine d'années comme des paysages marins menacés. Initialement décrits dans le golfe de Gabés, à proximité des îles Kerkennah, les herbiers tigrés se présentent sous forme " de rubans assez étroits qui se développent entre 0.5 et 3 m de profondeur sur matte ". La mise en place de nouveaux programmes d'études …
Climate change and Mediterranean seagrass meadows: a synopsis for environmental managers
12 páginas, 3 figuras
Unpublished Mediterranean records of marine alien and cryptogenic species
Este artículo contiene 18 páginas, 4 figuras.
Geospatial modelling and map analysis allowed measuring regression of the upper limit of Posidonia oceanica seagrass meadows under human pressure
Abstract Marine coastal ecosystems are facing structural and functional changes due to the increasing human footprint worldwide, and the assessment of their long-term changes becomes particularly challenging. Measures of change can be done by comparing the observed ecosystem status to a purposely defined reference condition. In this paper, a geospatial modelling approach based on 2D mapping and morphodynamic data was used to predict the natural position of the upper limit (i.e., the landward continuous front) of Posidonia oceanica seagrass meadows settled on soft bottom. This predictive model, formerly developed at the regional spatial scale, was here applied for the first time at the Medit…
Towards a framework for assessment and management of cumulative human impacts on marine food webs
Effective ecosystem-based management requires understanding ecosystem responses to multiple human threats, rather than focusing on single threats. To understand ecosystem responses to anthropogenic threats holistically, it is necessary to know how threats affect different components within ecosystems and ultimately alter ecosystem functioning. We used a case study of a Mediterranean seagrass (Posidonia oceanica) food web and expert knowledge elicitation in an application of the initial steps of a framework for assessment of cumulative human impacts on food webs. We produced a conceptual seagrass food web model, determined the main trophic relationships, identified the main threats to the fo…