Climate change in salt marshes - Effects of hydrodynamic forcing and higher temperatures on coastal vegetation

盐沼的气候变化 - 水动力强迫和高温对沿海植被的影响

• 批准号: 401564364
• 负责人: Professor Dr. Kai Jensen
• 金额: --
• 依托单位: Abteilung Angewandte Pflanzenökologie
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2018
• 资助国家: 德国
• 起止时间: 2017-12-31 至 2021-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/401564364?language=en
• 关键词: Climate; change; salt; marshes; Effects

Salt marshes and other coastal ecosystems provide important ecosystem services such as coastal protection, as the vegetation acts as an obstruction to hydrodynamic forces, thus leading to wave attenuation. While most studies so far have focused on the effects of vegetation on hydrodynamics, crucial knowledge on how hydrodynamics in turn affect and potentially damage salt marsh plants are missing. Additionally, effects of global warming on biophysical properties of marsh plants, which determine their wave attenuation capacity, are unknown. We will (i) quantify hydrodynamic forces using wave recording stations at the margin of Wadden Sea salt marshes and determine its spatial and temporal variation at sites differing in exposure. In parallel, vegetation structure and the eventual loss of biomass will be non-destructively determined and correlated to the recorded hydrodynamic conditions. Under controlled experimental conditions (ii) thresholds of hydrodynamic forces beyond which salt marsh plants suffer physical damage will be assessed in a true to scale flume study. We expect thresholds to be species specific, as plant species in salt marshes significantly differ in their biophysical properties such as plant flexibility. Furthermore, seasonal changes in these thresholds due to different plant development stages and differences in thresholds between single individuals of certain species and those associated in complex vegetation canopies will be determined. Finally, we will (iii) analyse effects of rising temperatures on biophysical properties and thus wave attenuation capacity of marsh plants in a world-unique whole ecosystem salt-marsh warming experiment. We expect that warming will increase above- and belowground biomass, prolong the growing season and increase the lignin content of plants. Overall, this might increase the coastal protection function of salt marshes in a warmer world. The results will be made available to be fed into both hydrodynamic models of wave impact on land-ward lying sea defences as well as into models of marsh evolution under different climate change and sea level rise scenarios. The findings will thus help to assess the coastal protection function of salt marshes adequately in the future and to better deal with impacts of ecological stochasticity and extreme events such as storm surges on coastal salt marshes.

盐沼和其他沿海生态系统提供了重要的生态系统服务，如海岸保护，因为植被阻碍了水动力，从而导致波浪衰减。虽然到目前为止，大多数研究都集中在植被对水动力学的影响上，但关于水动力学如何反过来影响和潜在破坏盐沼植物的关键知识却缺失了。此外，全球变暖对沼泽植物的生物物理特性的影响是未知的，这决定了它们的波衰减能力。我们将（i）使用瓦登海盐沼边缘的波浪记录站量化水动力，并确定其在不同暴露地点的空间和时间变化。与此同时，将以非破坏性方式确定植被结构和生物量的最终损失，并将其与记录的水动力条件相关联。在受控的实验条件下（二）阈值的水动力超过盐沼植物遭受物理损害将在一个真正的规模水槽研究进行评估。我们期望阈值是物种特异性的，因为盐沼中的植物物种在其生物物理特性如植物灵活性方面存在显着差异。此外，这些阈值的季节性变化，由于不同的植物发育阶段和某些物种的单个个体之间的阈值和那些在复杂的植被冠层相关的差异将被确定。最后，我们将（iii）分析生物物理特性的温度上升的影响，从而波衰减能力的沼泽植物在世界上唯一的整个生态系统的盐沼变暖实验。我们预计，变暖将增加地上和地下生物量，延长生长季节，增加植物的木质素含量。总的来说，这可能会增加盐沼在温暖世界中的海岸保护功能。研究结果将提供给波浪对向陆的海堤影响的水动力学模型以及不同气候变化和海平面上升情景下的沼泽演变模型。研究结果将有助于今后充分评估盐沼的海岸防护功能，更好地应对生态随机性和风暴潮等极端事件对海岸盐沼的影响。

项目成果

Survival of the thickest? Impacts of extreme wave‐forcing on marsh seedlings are mediated by species morphology

• DOI: 10.1002/lno.11850
• 发表时间: 2021-05
• 期刊: Limnology and Oceanography
• 影响因子: 4.5
• 作者: K. Schoutens;Svenja Reents;S. Nolte;B. Evans;M. Paul;M. Kudella;T. Bouma;I. Möller;S. Temmerman