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，例如沿海保护，因为植被起到了流体动力的阻塞，从而导致波浪衰减。尽管到目前为止的大多数研究都集中在植被对流体动力学的影响上，但有关流体动力学的关键知识又如何影响和潜在地损害盐沼植物。另外，全球变暖对沼泽植物生物物理特性的影响（决定其波浪衰减能力）是未知的。我们将（i）使用波浪记录站在Wadden海盐沼泽地的边缘量化流体动力，并确定其在暴露量不同的地点的空间和时间变化。同时，植被结构和最终的生物量丧失将是非破坏性确定的，并与记录的流体动力条件相关。在受控的实验条件下（ii），盐沼植物遭受物理损害的流体动力阈值将在规模水槽研究中评估。我们预计阈值是特定于物种的，因为盐沼泽中的植物物种在其生物物理特性（例如植物柔韧性）上显着差异。此外，将确定某些物种的单个个体与复杂植被檐篷相关的单个个体之间的不同植物发育阶段以及阈值的差异，这些阈值的季节性变化将得到确定。最后，我们将（iii）分析温度升高对生物物理特性的影响，从而在世界唯一的整个生态系统盐 - 盐 - 沼泽变暖实验中沼泽植物的波衰减能力。我们预计，变暖将增加高于和地下生物量，延长生长季节并增加植物的木质素含量。总体而言，这可能会增加温暖世界中盐沼的沿海保护功能。结果将被送入对陆地上撒谎的海洋防御措施的流动动力模型，以及在不同的气候变化和海平面上升场景下的沼泽进化模型。因此，这些发现将有助于将来充分评估盐沼的沿海保护功能，并更好地应对生态随机性和极端事件的影响，例如暴风雨对沿海盐沼泽的影响。

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