@article {3325, title = {Biogenic reefs affect multiple components of intertidal soft-bottom benthic assemblages: the Lanice conchilega case study}, journal = {Estuarine, Coastal and Shelf Science}, volume = {152}, year = {2015}, month = {01/2015}, pages = {44-55}, abstract = {

Biogenic reefs composed of the tube-building polychaete Lanice conchilega are important from a conservation point of view because they noticeably increase the biodiversity in otherwise species poor
environments. However, up to now, little or no attention has been paid to the intertidal epi- and hyperbenthic communities associated with the reefs. Therefore, this is the first study which focuses on
the effect of L. conchilega reefs on the entire bentho-pelagic community at two different locations. Environmental variables were measured and macro-, epi- and hyperbenthic communities were sampled
within a L. conchilega reef and a control area at two locations in France: the bay of the Mont Saint-Michel (BMSM) and Boulogne-sur-Mer (Boulogne). The effect of the reef presence on the benthic community
was studied with a 3-factor (Reef, Location and Period) Permanova. In addition, the relationship between the benthic community and the environmental variables was investigated using Distance-based linear
models (DistLM). Most collected organisms were sampled in the reef area (macrobenthos: 91\%, epibenthos: 81\% and hyperbenthos: 78.5\%) indicating that, independent of the location, the L. conchilega
reefs positively affect all three associated benthic communities. However, the extent of the effect seems to be most pronounced for the macrobenthos and less distinct in case of the hyperbenthos. The macro-,
and epibenthos are mainly structured by biotic variables (L. conchilega density and macrobenthic food availability respectively), while the hyperbenthos is rather structured by environmental variables. In
general, L. conchilega reefs do not only affect abundances and diversity but they substantially steer the structure of the intertidal benthic sandy beach ecosystem.

}, keywords = {beaches, benthos, biogenic reefs, community composition, Lanice conchilega, tidal flats}, doi = {doi:10.1016/j.ecss.2014.11.002}, author = {De Smet, Bart and D{\textquoteright}Hondt, An Sophie and Pieterjan, Verhelst and J{\'e}r{\^o}me Fournier and Laurent Godet and Nicolas Desroy and Rabaut, Marijn and Magda, Vincx and Jan, Vanaverbeke} } @article {Passarelli2013, title = {{Organisms as cooperative ecosystem engineers in intertidal flats}}, journal = {Journal of Sea Research}, volume = {92}, year = {2014}, month = {09/2014}, pages = {92-101}, abstract = {

The importance of facilitative interactions and organismal ecosystem engineering for establishing the structure of communities is increasingly being recognised for many different ecosystems. For example, soft-bottom tidal flats host a wide range of ecosystem engineers, probably because the harsh physico-chemical environmental conditions render these species of particular importance for community structure and function. These environments are therefore interesting when focusing on how ecosystem engineers interact and the consequences of these interactions on community dynamics. In this review, we initially detail the influence on benthic systems of two kinds of ecosystem engineers that are particularly common in tidal flats. Firstly, we examine species providing biogenic structures, which are often the only source of habitat complexity in these environments. Secondly, we focus on species whose activities alter sediment stability, which is a crucial feature structuring the dynamics of communities in tidal flats. The impacts of these engineers on both environment and communities were assessed but in addition the interaction between ecosystem engineers was examined. Habitat cascades occur when one engineer favours the development of another, which in turn creates or modifies and improves habitat for other species. Non-hierarchical interactions have often been shown to display non-additive effects, so that the effects of the association cannot be predicted from the effects of individual organisms. Here we propose the term of {\textquotedblleft}cooperative ecosystem engineering{\textquotedblright} when two species interact in a way which enhances habitat suitability as a result of a combined engineering effect. Finally, we conclude by describing the potential threats for ecosystem engineers in intertidal areas, potential effects on their interactions and their influence on communities and ecosystem function.

}, keywords = {Biogenic Structure, Cooperative Ecosystem Engineers, Habitat Cascade, Sediment stability, tidal flats}, doi = {10.1016/j.seares.2013.07.010}, author = {Passarelli, C and Fr{\'e}d{\'e}ric Olivier and Paterson, D M and Tarik Meziane and C{\'e}dric Hubas} }