Coping with wave effects: Plasticity in physiology and biomechanics of Suaeda salsa colonization in the Yellow River Delta

Abstract

In order to enhance the ecological security of the coastal ecosystem, the Chinese government has initiated a comprehensive program for the removal of Spartina alterniflora. Upon completion of the removal project, the area underwent a notable transformation, transitioning from its original vegetated state to a predominantly bare salt marsh landscape. This transformation has the potential to give rise to new ecological security issues and facilitate the re-invasion of Spartina alterniflora. At the time of writing, restoration work is underway in the restoration area, with the aim of reinstating native vegetation, specifically Suaeda salsa. Nevertheless, the survival strategies that the target species, Suaeda salsa, may employ to adapt to the challenging wave environment remain unknown, potentially introducing unforeseen challenges to the revegetation efforts. To address this issue, we conducted a study to examine the impact of water-imposed drag forces on the physiological and biomechanical properties of Suaeda salsa, with the aim of defining its survival strategies in wave environments. Our research findings indicate that Suaeda salsa exhibits limited sensitivity to wave disturbance. Suaeda salsa is relatively rigid and thus finds it difficult to adjust its shape flexibly in order to withstand the mechanical force caused by wave motion. As the intensity of the wave increases, Suaeda salsa exhibits a tolerance strategy. In the optimal wave environment (before the failure of plant tissue under extreme wave drag force), enhanced waves can stimulate the growth of Suaeda salsa, thus potentially contributing positively to the restoration efforts of the Yellow River Delta.