Biogeomorphology of the Mediterranean Posidonia oceanica seagrass meadows

Abstract

Here we review the multiple interactions between the endemic Mediterranean seagrass, Posidonia oceanica, and coastal geomorphologic processes as an outstanding example of biogeomorphology, taking into account recent advances in the field. Seagrass meadows are among the most important elements for the functioning of marine coastal ecosystems, and represent a major focus for research and conservation. Being considered a priority habitat, P. oceanica meadows are protected by several European Union directives and national laws. In this paper we examine: the role of sedimentary features in controlling the development of the meadows; the interplay between P. oceanica leaf litter (i.e. beached necromass) cast ashore and erosional-depositional processes on the beaches; the interactions between meadows and nearshore hydrodynamics, and; possible linkages between geomorphological features of the seafloor and the architecture of meadows. Finally, we provide perspectives for future research on P. oceanica and other Mediterranean seagrass meadows in a biogeomorphological context with specific reference to climate change.

Seascape ecology in Posidonia oceanica seagrass meadows: Linking structure and ecological processes for management

“…References to in situ studies were extracted from previous reviews concerning seagrass seascapes (Boström et al, 2006(Boström et al, , 2011Connolly and Hindell, 2006;Grober-Dunsmore et al, 2009;Heck et al, 2008;Horinouchi, 2007;Kendrick et al, 2005a;Vacchi et al, 2017). To complete this first approach, a search was then performed using the Scopus and Google Scholar data bases, using the keywords 'seagrass'; 'landscape'; 'seascape'; 'patch'; 'structure' and 'architecture'.…”

“…At greater water depths, even if negligible, currents derived from wave energy result in a decrease of meadow cover resulting in the generation of patches of different bottom type (bare matte or sandy bottom) (Abadie et al, 2017;Gobert et al, 2016;Vacchi et al, 2010). Furthermore, P. oceanica meadows enhance sediment stabilization of sandy patches present in their vicinity (Vacchi et al, 2017). At the large spatial scale, sandy patches intermixed within a P. oceanica meadow are clearly recognizable, as shown by side scan sonar images, and can occupy from 2% to 16% of the total seagrass meadow area Clabaut et al, 2014;Pasqualini et al, 2000;Pasqualini et al, 1999).…”

“…7). Through export of primary production and their influence on water movement (Vacchi et al, 2017), P. oceanica meadows interact with other habitats, both marine and terrestrial (Heck et al, 2008), thus connecting with the whole Mediterranean coastal landscape and seascape.…”

Morphodynamics of a Mediterranean microtidal wave-dominated beach: forms, processes and insights for coastal management

“…The ecogeomorphological role of P. oceanica meadow in Mediterranean coastal environments has been inves- Simeone, De Muro, & De Falco, 2013;Tecchiato, Buosi, Ibba, Ryan, & De Muro, 2016;Vacchi, De Falco et al, 2016). P. oceanica meadow occurs along the whole studied coastal sector.…”

“…This plays a crucial role in the physical equilibrium of the Mediterranean coast (Vacchi, De Falco et al, 2016). The worldwide regression of the P. oceanica meadow ecosystem is one of the most pressing issues in marine environments (Boudouresque, Bernard, Pergent, Shili, & Verlaque, 2009).…”