Survival of the thickest? Impacts of extreme wave‐forcing on marsh seedlings are mediated by species morphology
Survival of the thickest? Impacts of extreme wave‐forcing on marsh seedlings are mediated by species morphology
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DOI：
10.1002/lno.11850
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发表时间：
2021-05
影响因子：
4.5
通讯作者：
K. Schoutens;Svenja Reents;S. Nolte;B. Evans;M. Paul;M. Kudella;T. Bouma;I. Möller;S. Temmerman
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文献类型：
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作者：
K. Schoutens;Svenja Reents;S. Nolte;B. Evans;M. Paul;M. Kudella;T. Bouma;I. Möller;S. Temmerman
虽然潮汐沼泽在风暴潮期间具有海岸防御功能，但人们对极端海浪强迫对潮汐沼泽发育的影响知之甚少。幼苗在萌发后的第一个季节存活，这可能涉及到极端海浪事件，对沼泽的自然建立和人类恢复至关重要。我们推测，物种特有的植物性状在幼苗的存活和对波浪诱导的胁迫的响应中发挥着重要作用，即通过茎弯曲和连根拔起。为了验证这一假设，将生物物理特性不同的先锋物种(BolBoschoenus maritimus、Schoenopectus tabernaemontani、Spartina Anglica和Puccinellia maritima)的幼苗放置在德国汉诺威的大浪槽中，并暴露在暴风浪条件下。马尾松和马尾松幼苗在波浪暴露后的损失率和弯曲角均低于马尾松，尤其是马尾松。较高的损失率是由于茎底部周围较深的冲刷造成的。直径越大、抗弯能力越强的树干，冲刷深度越大。在这里，B.maritimus和S.taberneemontani的茎都比S.Anglica和P.maritima更粗和更硬。我们的结果表明，特别是茎粗的幼苗遭受侵蚀和冲刷，在极端海浪事件中丢失的风险最高。这表明，对于成功的育苗和最终建立成熟的潮汐湿地植被来说，物种组成和它们应对风浪干扰的能力是至关重要的。
Although tidal marshes are known for their coastal defense function during storm surges, the impact of extreme wave forcing on tidal marsh development is poorly understood. Seedling survival in the first season after germination, which may involve exposure to extreme wave events, is crucial for the natural establishment and human restoration of marshes. We hypothesize that species‐specific plant traits plays a significant role in seedlings survival and response to wave induced stress, i.e., through stem bending and uprooting. To test this hypothesis, seedlings of pioneer species (Bolboschoenus maritimus, Schoenoplectus tabernaemontani, Spartina anglica, and Puccinellia maritima) with contrasting biophysical traits were placed in the Large Wave Flume in Hannover (Germany) and exposed to storm wave conditions. Seedlings of P. maritima and S. anglica experienced a lower loss rate and bending angle after wave exposure compared to S. tabernaemontani and especially B. maritimus. The higher loss rates of B. maritimus and S. tabernaemontani result from deeper scouring around the stem base. Scouring depth was larger around stems of greater diameter and higher resistance to bending. Here, B. maritimus and S. tabernaemontani have both thicker and stiffer stems than S. anglica and P. maritima. Our results show that especially seedlings with thicker stems suffer from erosion and scouring, and have the highest risk of being lost during extreme wave events. This implies that for successful seedling establishment and eventually the establishment of a mature tidal marsh vegetation, the species composition and their capacity to cope with storm wave disturbances is crucial.