Zarnetske Phoebe L, Ruggiero Peter, Seabloom Eric W, Hacker Sally D
Department of Integrative Biology, Oregon State University, 3029 Cordley Hall, Corvallis, OR 97331, USA
College of Earth, Ocean, and Atmospheric Sciences, Oregon State University, 104 CEOAS Administration Building, Corvallis, OR 97331, USA.
J R Soc Interface. 2015 May 6;12(106). doi: 10.1098/rsif.2015.0017.
Biophysical feedbacks between vegetation and sediment are important for forming and modifying landscape features and their ecosystem services. These feedbacks are especially important where landscape features differ in their provision of ecosystem services. For example, the shape of coastal foredunes, a product of both physical and biological forces, determines their ability to protect communities from rising seas and changing patterns of storminess. Here we assessed how sand supply and changes in vegetation over interannual (3 year) and decadal (21 year) scales influenced foredune shape along 100 km of coastline in the US Pacific Northwest. Across 21 years, vegetation switched from one congeneric non-native beachgrass to another (Ammophila arenaria to A. breviligulata) while sand supply rates were positive. At interannual timescales, sand supply rates explained the majority of change in foredune height (64-69%) and width (56-80%). However, at decadal scales, change in vegetation explained the majority of the change in foredune width (62-68%), whereas sand supply rates explained most of the change in foredune height (88-90%). In areas with lower shoreline change rates (±2 m yr(-1)), the change in vegetation explained the majority of decadal changes in foredune width (56-57%) and height (59-76%). Foredune shape directly impacts coastal protection, thus our findings are pertinent to coastal management given pressures of development and climate change.
植被与沉积物之间的生物物理反馈对于形成和改变景观特征及其生态系统服务至关重要。在景观特征在提供生态系统服务方面存在差异的地方，这些反馈尤为重要。例如，海岸前沙丘的形状是物理和生物力量共同作用的产物，它决定了其保护社区免受海平面上升和风暴模式变化影响的能力。在这里，我们评估了在年际（3年）和年代际（21年）尺度上，沙子供应和植被变化如何影响美国太平洋西北部100公里海岸线沿线的前沙丘形状。在21年的时间里，植被从一种同属的非本地海滩草转变为另一种（沙蚕草变为短叶沙蚕草），而沙子供应率为正值。在年际时间尺度上，沙子供应率解释了前沙丘高度变化的大部分（64 - 69%）和宽度变化的大部分（56 - 80%）。然而，在年代际尺度上，植被变化解释了前沙丘宽度变化的大部分（62 - 68%），而沙子供应率解释了前沙丘高度变化的大部分（88 - 90%）。在海岸线变化率较低（±2米/年）的地区，植被变化解释了前沙丘宽度年代际变化的大部分（56 - 57%）和高度年代际变化的大部分（59 - 76%）。前沙丘形状直接影响海岸保护，因此鉴于发展和气候变化的压力，我们的研究结果与海岸管理相关。
