Critical slowing down: vegetation height, cover and composition assess resilience of tidal fresh, brackish and salt marshes following experimental disturbance at twelve sites across the estuarine landscape

We investigated the relative recovery rates of vegetation cover, vegetation height and community composition over a period of >10 years after experimental disturbance in 12 tidal marshes (two oligohaline, three mesohaline and seven polyhaline sites) across the estuarine landscape on the coast of Georgia, USA. Vegetation was removed from three by three meter plots (four per site) with herbicide in 2006 followed by repeated clipping through 2009. Vegetation height, cover and composition was assessed in experimental and control plots (4 of each per site) from 2010 to 2020. The goal of the study was to assess how quickly the sites recovered from disturbance, how this varied in different types of marshes, and how results varied depending on whether recovery was assessed by vegetation height, cover or composition.

本研究针对美国佐治亚州海岸河口沿岸的12处潮汐盐沼（tidal marshes）展开，其中包含2处寡盐沼（oligohaline）、3处中盐沼（mesohaline）及7处多盐沼（polyhaline）样点，旨在探究实验性干扰（experimental disturbance）发生后，时长超10年的周期内植被盖度、植被高度与群落组成的相对恢复速率。2006年，研究人员通过除草剂清除了每个样点内4块3米×3米样地的植被，并在2009年前持续开展刈割处理。2010年至2020年期间，研究人员对每个样点的4块实验样地与4块对照样地的植被高度、盖度及群落组成进行了测定评估。本研究的核心目标为：明确各盐沼样点受干扰后的恢复速度，探究不同类型盐沼的恢复差异，以及基于植被高度、盖度或群落组成这三类不同评估指标所得出的恢复结果差异。