Flow Velocity and Morphology of a Submerged Patch of the Aquatic Species Veronica anagallis-aquatica L

The interaction between macrophytes and hydrodynamic conditions is animportant feature in many aquatic ecosystems. Submerged macrophytes can formmonospecific patches that interact with the flow and alter current velocity; withinthe same vegetation patch, plants are exposed to different levels of hydrodynamicstress. Due to the high morphological variability of aquatic plants, we expect differentarchitectural and morphological traits to emerge for individuals located atdifferent positions within the same patch. In this study, we have measured the flowvelocity around a patch of Veronica anagallis-aquatica in submerged conditionsand measured the morphological traits of individuals along a gradient of exposureto flow velocity within the patch. Results show that the more exposed individualspresent smaller sizes than the sheltered ones, lower relative allocation to stems,higher allocation to roots and reduced water content in roots and stems. Theknowledge obtained helps to clarify the role of morphological adaptations to flowstress in the context of plant-flow interactions.