Abstract A time-series (1990–2013) of classified vegetation cover maps was produced for Netley-Libau Marsh, a 26,000 ha coastal wetland on Lake Winnipeg, to assess its current status and verify earlier trends of emergent vegetation loss. Open water area in the marsh was measured from late-summer Landsat images for 20 years; three classes of vegetation types (emergents, wet meadows, upland) could also be identified for 12 images covering the same period. Temporal changes in area and distribution of marsh vegetation were related to adjoining Lake Winnipeg water-level and Red River discharge, as well as marsh connectivity and bathymetry. From 1990 to 2002, an increase in open-water areas and decrease in emergent vegetation coincided with rising levels and flows. The year 2003 marked major wetland regeneration and a decrease of open-water area under extremely low water-levels and flows. From 2005 to 2013, open-water area remained consistent, under high but variable levels and flows. A strong negative correlation was found between area of emergent vegetation and mean Red River discharge in the previous June-July. Superimposition of the limit of new emergent vegetation observed in 2003 with depth contours surveyed in 2010 revealed the dynamic nature of marsh bathymetry. Periods of extremely low water as short as one year (2003) induced a marked expansion in emergent vegetation cover that persisted over the next ten years despite higher water-levels. Rather than being gradual, changes in the spatial extent of Netley-Libau Marsh vegetation appeared to proceed by fits and starts, wherein periods of relative stasis were disrupted by major changes in abundance.

中文翻译：

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Netley-Libau Marsh 中的新兴植被：与温尼伯湖水位和红河流量相关的覆盖的时间变化（1990-2013）

摘要 为 Netley-Libau Marsh（温尼伯湖上 26,000 公顷的沿海湿地）制作了分类植被覆盖图的时间序列（1990-2013），以评估其现状并验证新兴植被损失的早期趋势。沼泽中的开阔水域面积是根据 20 年的夏末 Landsat 图像测量的；对于覆盖同一时期的 12 张图像，还可以识别三类植被类型（新兴、湿草甸、高地）。沼泽植被面积和分布的时间变化与毗邻的温尼伯湖水位和红河流量以及沼泽连通性和水深有关。从 1990 年到 2002 年，开阔水域的增加和挺水植被的减少与水位和流量的上升同时发生。2003年是湿地大面积更新和极低水位流下开放水域面积减少的一年。从 2005 年到 2013 年，开放水域保持一致，处于高水平和可变水平和流量。前 6-7 月，挺水植被面积与红河平均流量呈显着负相关。2003 年观察到的新出现植被的极限与 2010 年调查的深度等值线的叠加揭示了沼泽测深的动态性质。尽管水位较高，但短至一年（2003 年）的极低水期导致挺水植被覆盖显着扩大，并在接下来的十年中持续存在。Netley-Libau Marsh 植被空间范围的变化不是渐进的，而是断断续续地进行，