Identifying Hydro-Geomorphological Conditions for State Shifts from Bare Tidal Flats to Vegetated Tidal Marshes
Identifying Hydro-Geomorphological Conditions for State Shifts from Bare Tidal Flats to Vegetated Tidal Marshes
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DOI：
10.3390/rs12142316
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发表时间：
2020-07-01
期刊：
影响因子：
5
通讯作者：
Temmerman, Stijn
中科院分区：
文献类型：
--
作者：
Wang, Chen;Smolders, Sven;Temmerman, Stijn
高海拔植被沼泽和低海拔裸露滩涂是潮间带生态系统的两种稳定状态。能够确定的条件，使这两个稳定状态之间的转换是非常重要的生态系统管理，特别是恢复潮沼生态系统。然而，调查从裸露的泥滩到植被沼泽的状态转变条件的研究数量仍然相对较低。我们开发了一个GIS的方法来确定的位置，从裸露的潮间带植被沼泽沿着一个大的河口（西斯海尔德河口，荷兰西南部），通过分析植被生物量，海拔，潮流和风浪的空间格局之间的相互作用。我们分析了用于定位沼泽的假彩色航空图像，基于激光雷达的数字高程模型，以及整个河口尺度（类似于326 km（2））的潮流和风浪的空间模型模拟。我们的结果表明：（1）植被生物量与潮间高程的双峰性共存;（2）在低海拔裸露状态与高海拔植被状态的过渡期，潮流和风浪发生突变。这些研究结果表明，植被生长，电流，波浪和沉积物动力学之间的生态反馈导致的状态从裸露的泥滩植被沼泽。我们的研究结果转化为GIS方法（逻辑回归），以确定在研究期间的海拔，电流和波轨道速度的空间模式的基础上，从裸露到植被状态的转变的位置。该方法可为滩涂的管理和恢复提供科学依据。
High-lying vegetated marshes and low-lying bare mudflats have been suggested to be two stable states in intertidal ecosystems. Being able to identify the conditions enabling the shifts between these two stable states is of great importance for ecosystem management in general and the restoration of tidal marsh ecosystems in particular. However, the number of studies investigating the conditions for state shifts from bare mudflats to vegetated marshes remains relatively low. We developed a GIS approach to identify the locations of expected shifts from bare intertidal flats to vegetated marshes along a large estuary (Western Scheldt estuary, SW Netherlands), by analyzing the interactions between spatial patterns of vegetation biomass, elevation, tidal currents, and wind waves. We analyzed false-color aerial images for locating marshes, LIDAR-based digital elevation models, and spatial model simulations of tidal currents and wind waves at the whole estuary scale (similar to 326 km(2)). Our results demonstrate that: (1) Bimodality in vegetation biomass and intertidal elevation co-occur; (2) the tidal currents and wind waves change abruptly at the transitions between the low-elevation bare state and high-elevation vegetated state. These findings suggest that biogeomorphic feedback between vegetation growth, currents, waves, and sediment dynamics causes the state shifts from bare mudflats to vegetated marshes. Our findings are translated into a GIS approach (logistic regression) to identify the locations of shifts from bare to vegetated states during the studied period based on spatial patterns of elevation, current, and wave orbital velocities. This GIS approach can provide a scientific basis for the management and restoration of tidal marshes.