The vegetation communities within semi-permanent or ephemeral montane marshes colloquially known as lagoons are an under investigated wetland type of the New England Tablelands Bioregion (NETB) yet they are listed (Upland Wetlands) on both state and federal acts as endangered. Lack of survey and analysis of plot data has meant that the variation in vegetation due to zonation, seasonality and unpredictable wetting and drying cycles are poorly understood. Here, 317 full floristic 2 × 2-m plots were placed across 13 lagoons. The plot data were classified to allow description of native and novel vegetation types using the hierarchical EcoVeg schema. The updated classification includes one Division and Macrogroup with 15 Alliances and 47 Associations. Permanent 50-m transects with a 1 × 1-m plot at every 5 m (10 per transect) were placed within lagoons. Five lagoons were resurveyed annually for 3 years. Within transects, each plot was assigned an Association after each survey period. Approximately one third of transect plots changed in vegetation type each year, often at the Alliance level. Over the 3-year period the number of Associations reduced by ~30% across transects associated with increasing drought and drying out of the wetlands. Transitional environments with the greatest level of hydrological periodicity had the greatest variety of Associations recorded. Highly dynamic systems with increased temporal turnover are likely to require increased sampling effort both spatially and temporally than more stable vegetated systems. The constant changing nature of these communities poses significant issues for management and conservation planning, including benchmarking and offsetting, which may require novel solutions.

半永久性或临时性山地沼泽中的植被群落俗称泻湖，是新英格兰平原生物区（NETB）的一项经过调查的湿地类型，但在州和联邦政府中均被列为（高地湿地）濒危物种。缺乏对地块数据的调查和分析意味着人们对由于分区，季节性和不可预测的湿润和干燥周期造成的植被变化知之甚少。在这里，在13个泻湖上放置了317个全植物区系2×2-m样地。对地块数据进行分类，以允许使用分层的EcoVeg模式描述原生和新型植被类型。更新后的分类包括一个分区和宏组，以及15个联盟和47个协会。在每5 m上以1×1-m绘制的永久50 m样带（每个样带10个）放置在泻湖中。每年对五个泻湖进行重新调查，历时3年。在样条线内，在每个调查期后为每个地块分配一个关联。每年大约有三分之一的样地改变了植被类型，通常是在联盟级别。在过去的三年中，与干旱增加和湿地干燥有关的样带协会数量减少了约30％。具有最大水文周期性的过渡环境记录的协会种类最多。与更稳定的植被系统相比，具有更高时间转换的高度动态系统可能在空间和时间上都需要增加采样工作。这些社区不断变化的性质对管理和保护规划提出了重要问题，包括基准测试和补偿，