title: Ecosystem Engineering by Plants on Wave-Exposed Intertidal Flats Is Governed by Relationships between Effect and Response Traits.
abstract: In hydrodynamically stressful environments, some species--known as ecosystem engineers--are able to modify the environment for their own benefit. Little is known however, about the interaction between functional plant traits and ecosystem engineering. We studied the responses of Scirpus tabernaemontani and Scirpus maritimus to wave impact in full-scale flume experiments. Stem density and biomass were used to predict the ecosystem engineering effect of wave attenuation. Also the drag force on plants, their bending angle after wave impact and the stem biomechanical properties were quantified as both responses of stress experienced and effects on ecosystem engineering. We analyzed lignin, cellulose, and silica contents as traits likely effecting stress resistance (avoidance, tolerance). Stem density and biomass were strong predictors for wave attenuation, S. maritimus showing a higher effect than S. tabernaemontani. The drag force and drag force per wet frontal area both differed significantly between the species at shallow water depths (20 cm). At greater depths (35 cm), drag forces and bending angles were significantly higher for S. maritimus than for S. tabernaemontani. However, they do not differ in drag force per wet frontal area due to the larger plant surface of S. maritimus. Stem resistance to breaking and stem flexibility were significantly higher in S. tabernaemontani, having a higher cellulose concentration and a larger cross-section in its basal stem parts. S. maritimus had clearly more lignin and silica contents in the basal stem parts than S. tabernaemontani. We concluded that the effect of biomass seems more relevant for the engineering effect of emergent macrophytes with leaves than species morphology: S. tabernaemontani has avoiding traits with minor effects on wave attenuation; S. maritimus has tolerating traits with larger effects. This implies that ecosystem engineering effects are directly linked with traits affecting species stress resistance and responding to stress experienced.
authors.affiliation: Department Ecological Interactions, Federal Institute of Hydrology, Koblenz, Germany; Geoinformation in Environmental Planning Lab, Technische Universität Berlin, Berlin, Berlin, Germany.
authors.forename: Maike
authors.initials: M
authors.lastname: Heuner
authors.affiliation: Department of Biology, Ecosystem Management Research Group, University of Antwerp, Wilrijk, Belgium.
authors.forename: Alexandra
authors.initials: A
authors.lastname: Silinski
authors.affiliation: Department of Biology, Ecosystem Management Research Group, University of Antwerp, Wilrijk, Belgium.
authors.forename: Jonas
authors.initials: J
authors.lastname: Schoelynck
authors.affiliation: Centre for Estuarine and Marine Ecology, Royal Netherlands Institute for Sea Research, Yerseke, The Netherlands.
authors.forename: Tjeerd J
authors.initials: TJ
authors.lastname: Bouma
authors.affiliation: UMR 5023 LEHNA, CNRS, Université Lyon 1, ENTPE, Villeurbanne, France.
authors.forename: Sara
authors.initials: S
authors.lastname: Puijalon
authors.affiliation: Department of Civil Engineering, Ghent University, Ghent, Belgium.
authors.forename: Peter
authors.initials: P
authors.lastname: Troch
authors.affiliation: Department Ecological Interactions, Federal Institute of Hydrology, Koblenz, Germany.
authors.forename: Elmar
authors.initials: E
authors.lastname: Fuchs
authors.affiliation: Institute of Geoecology, Environmental Systems Analysis, Technische Universität Braunschweig, Braunschweig, Germany; Berlin-Brandenburg Institute of Advanced Biodiversity Research (BBIB), Berlin, Germany.
authors.forename: Boris
authors.initials: B
authors.lastname: Schröder
authors.affiliation: Department Vegetation Studies & Landscape Management, Federal Institute of Hydrology, Koblenz, Germany.
authors.forename: Uwe
authors.initials: U
authors.lastname: Schröder
authors.affiliation: Department of Biology, Ecosystem Management Research Group, University of Antwerp, Wilrijk, Belgium.
authors.forename: Patrick
authors.initials: P
authors.lastname: Meire
authors.affiliation: Department of Biology, Ecosystem Management Research Group, University of Antwerp, Wilrijk, Belgium.
authors.forename: Stijn
authors.initials: S
authors.lastname: Temmerman
mesh_terms: D002482:Cellulose / Q000096:biosynthesis*; D029785:Cyperaceae / Q000254:growth & development*; D017753:Ecosystem; D018547:Plant Stems / Q000254:growth & development*; D055871:Tidal Waves
chemical_list: D002482:Cellulose