Details

Autor(en) / Beteiligte

• Abadie, Arnaud
• Gobert, Sylvie
• Bonacorsi, Marina
• Lejeune, Pierre
• Pergent, Gérard
• Pergent-Martini, Christine

Titel

Marine space ecology and seagrasses. Does patch type matter in Posidonia oceanica seascapes?

Ist Teil von

• Ecological indicators, 2015-10, Vol.57, p.435-446

Ort / Verlag

Elsevier Ltd

Erscheinungsjahr

2015

Link zum Volltext

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• •11 types of patches of natural or human origin are described and classified.•Main P. oceanica seascapes characteristics are driven by few types of patches.•Natural patches follow a singular distribution from the lower limit of the meadow.•We create an index that assesses the patchiness source for seagrass meadows. The use of landscape tools in the study of seagrass meadows (seascapes) begins to be widely spread but still require the establishment of several basis, i.e. a patch type classification based on numerical characteristics. Thanks to the complex seascapes created by the Posidonia oceanica meadows, they appear to be suitable for a study at a patch type level (class), which bring a new insight of their arrangement at the whole seascape scale. By interpreting side scan sonar images from the Corsican coast (France) through a GIS software, it was possible to describe 11 types of patches and to evaluate their natural or anthropogenic origin. Comparison of different landscape metrics and wave exposure (Relative wave Exposure Index, REI) at the seascape and the patch level showed that the particularity of P. oceanica seascapes are mainly characterized by certain types of patches often of anthropogenic origin. Furthermore the REI seems not to be a relevant index for a study at a class scale. A bathymetrical succession of natural patches was outlined from the lower to the upper limit of the meadow, with a long-term dynamic opposed to a shorter one concerning anthropogenic patches. In order to assess the origin (natural or induced by human activities) of the patches in P. oceanica meadows, as well as in any other seagrass, a Patchiness Source Index (PaSI), ranging from 0 to 1, was defined.