Haobing Cao1,2,3, Zhenchang Zhu2,4, Rebecca James2, Peter M J Herman3,5, Liquan Zhang1, Lin Yuan1,6, Tjeerd J Bouma2,7. 1. State Key Laboratory of Estuarine and Coastal Research, East China Normal University, Shanghai, China. 2. NIOZ Royal Netherlands Institute for Sea Research, Department of Estuarine and Delta Systems, and Utrecht University, Yerseke, The Netherlands. 3. Hydraulic Engineering Department, Delft University of Technology, Delft, The Netherlands. 4. Institute of Environmental and Ecological Engineering, Guangdong University of Technology, Guangzhou, China. 5. Deltares, Delft, The Netherlands. 6. Institute of Eco-Chongming, East China Normal University, Shanghai, China. 7. Faculty of Geosciences, Utrecht University, Utrecht, The Netherlands.
Abstract
BACKGROUND AND AIMS: It is important to have an in-depth mechanistic understanding of tidal marsh establishment and dynamics to ensure the long-term persistence of these valuable ecosystems. As wave forcing may be expected to impact seedling establishment, we studied the effect of water-imposed drag forces on seedling survival, morphology and biomechanical properties of three marsh pioneer species that are dominant along the salinity gradient in many areas around the world: Spartina anglica (salt to brackish), Scirpus maritimus (brackish) and Phragmites australis (brackish to fresh). METHODS: Using a newly developed plant-shaking mesocosm (PSM) that mimicked water-imposed wave drag forces, the effect of wave stress on seedling survival was examined, together with impacts on morphology and biomechanical properties. KEY RESULTS: After 7 weeks of exposure to wave stress, lowered seedling survival and growth for all species was revealed. Wave treatments increased the root/shoot biomass ratio to enhance anchorage and made seedlings more flexible (i.e. reduced flexural rigidity), which might be regarded as a mixed outcome between a stress avoidance and stress tolerance strategy. CONCLUSIONS: The different biomechanical responses between the three dominant marsh pioneer species, overall, make them less resistant to external stress. Therefore, our results indicate that the likelihood of marshes becoming established is reduced if wave energy increases. Despite the different biomechanical response of these three pioneer species to waves, the seedlings of all species were found to have low resistance to external stresses.
BACKGROUND AND AIMS: It is important to have an in-depth mechanistic understanding of tidal marsh establishment and dynamics to ensure the long-term persistence of these valuable ecosystems. As wave forcing may be expected to impact seedling establishment, we studied the effect of water-imposed drag forces on seedling survival, morphology and biomechanical properties of three marsh pioneer species that are dominant along the salinity gradient in many areas around the world: Spartina anglica (salt to brackish), Scirpus maritimus (brackish) and Phragmites australis (brackish to fresh). METHODS: Using a newly developed plant-shaking mesocosm (PSM) that mimicked water-imposed wave drag forces, the effect of wave stress on seedling survival was examined, together with impacts on morphology and biomechanical properties. KEY RESULTS: After 7 weeks of exposure to wave stress, lowered seedling survival and growth for all species was revealed. Wave treatments increased the root/shoot biomass ratio to enhance anchorage and made seedlings more flexible (i.e. reduced flexural rigidity), which might be regarded as a mixed outcome between a stress avoidance and stress tolerance strategy. CONCLUSIONS: The different biomechanical responses between the three dominant marsh pioneer species, overall, make them less resistant to external stress. Therefore, our results indicate that the likelihood of marshes becoming established is reduced if wave energy increases. Despite the different biomechanical response of these three pioneer species to waves, the seedlings of all species were found to have low resistance to external stresses.
Authors: Daniel A Friess; Ken W Krauss; Erik M Horstman; Thorsten Balke; Tjeerd J Bouma; Demis Galli; Edward L Webb Journal: Biol Rev Camb Philos Soc Date: 2011-09-19
Authors: Sara Puijalon; Tjeerd J Bouma; Christophe J Douady; Jan van Groenendael; Niels P R Anten; Evelyne Martel; Gudrun Bornette Journal: New Phytol Date: 2011-05-17 Impact factor: 10.151
Authors: Alexandra Silinski; Maike Heuner; Jonas Schoelynck; Sara Puijalon; Uwe Schröder; Elmar Fuchs; Peter Troch; Tjeerd J Bouma; Patrick Meire; Stijn Temmerman Journal: PLoS One Date: 2015-03-23 Impact factor: 3.240