Flow-resistance adaptations of rigid-stemmed aquatic macrophytes in simulated water channels

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• 作者：Shiang-Yuarn Chen
• 关键词：Interspecific difference ; Flow ; resistance mechanism ; Morphological adaptation ; Slope stability ; Artificial flume ; Ecological engineering
• 刊名：Landscape and Ecological Engineering
• 出版年：2017
• 出版时间：January 2017
• 年：2017
• 卷：13
• 期：1
• 页码：157-167
• 全文大小：
• 刊物类别：Earth and Environmental Science
• 刊物主题：Landscape Ecology; Nature Conservation; Civil Engineering; Environmental Management; Landscape/Regional and Urban Planning; Plant Ecology;
• 出版者：Springer Japan
• ISSN：1860-188X
• 卷排序：13

文摘

This study investigated the development of interspecific adaptations of flow-resistance mechanisms to higher flow rates in rigid-stemmed Hygrophila salicifolia (Vahl) Nees (willow leaf Hygrophila sp.) plants placed in simulated water channels. The results indicate that adaptations to higher flow rates include a reduction in: growth rate, average fresh weight, average dry weight, and average diameter; but an increase in the number of parallel shoots. These effects combine to create a streamlined profile, reduce plant damage, and increase propagation through adventitious budding. Higher flow rates also reduced the ratio of average plant height to average root length in rigid-stemmed Hygrophila sp. The increased root length, strengthening of plant anchors, and reduction of uprooting seen at higher flow rates are likely to increase slope stability and reduce riverbank topsoil runoff. Moreover, rigid-stemmed aquatic macrophytes develop different adaptations than flexible-stemmed water plants (e.g., water celery); for these plants, higher flow velocities trigger an increase in the average density of vascular bundles and a reduction of the average root length, which results in uprooting and movement to different locations. These results suggest that different aquatic macrophytes play different roles in water channels. Our methods and findings can inform further investigations into the roles played by different aquatic macrophytes in ecological engineering and help to identify optimal planting materials or precursors for riverbanks.