Montane riparian meadows foster biodiversity and support critical ecosystem services. A history of exploitation has left most riparianmeadows throughout theMountainWest of the United States with incised channels, severely compromising their functionality. Hydrologic restoration of riparian meadows aims to increase overbank flow during spring run-off and elevate groundwater levels in the dry season. Outcome-based evaluations of the dominant meadow restoration methods are lacking and needed to ensure objectives are being met and to guide modifications where needed. We completed 1,282 point count surveys from 2009 to 2017 at 173 sampling locations across 31 montane riparian meadows in California restored using partial channel fill techniques (e.g. pond-and-plug) to evaluate the expected outcome of increased abundance of meadow birds. We analyzed trends in abundance for 12 focal bird species from 1 to 18 years after hydrologic restoration, substituting space for time in our mixed effects Poisson regression models that included covariates for the amount of riparian deciduous vegetation (RDV) before restoration, stream flow, precipitation, and temperature.We found evidence for a positive effect of time since restoration on abundance for 6 of the 12 species. Although pre-restoration RDV cover was the most frequently supported predictor of abundance, high pre-restoration cover of RDV slowed response rates for only two species, suggesting other elements of hydrologic function are also important for meadow birds. Drawing on our results, we provide suggestions for enhancing hydrologic restoration efforts in riparian meadows so that benefits may accrue more quickly to more bird species.

中文翻译：

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鸟类对山地河岸草甸水文恢复的反应

山地河岸草甸促进生物多样性并支持关键的生态系统服务。开发的历史使整个美国西部山区的大多数河岸草甸都有切割通道，严重损害了它们的功能。河岸草甸的水文恢复旨在增加春季径流期间的溢流，并在旱季提高地下水位。缺乏并需要对主要草地恢复方法进行基于结果的评估，以确保实现目标并在需要时指导修改。从 2009 年到 2017 年，我们在加利福尼亚州 31 个山地河岸草甸的 173 个采样点完成了 1,282 点计数调查，这些采样点使用部分渠道填充技术（例如池塘和塞子）恢复，以评估草甸鸟类数量增加的预期结果。我们分析了水文恢复后 1 到 18 年 12 种重点鸟类的丰度趋势，在我们的混合效应泊松回归模型中用空间代替时间，其中包括恢复前河岸落叶植被 (RDV) 数量的协变量、河流流量、降水和温度。我们发现了自恢复以来时间对 12 个物种中 6 个物种的丰度有积极影响的证据。尽管恢复前的 RDV 覆盖率是最常被支持的丰度预测因子，但恢复前 RDV 的高覆盖率仅减慢了两个物种的响应速度，这表明水文功能的其他要素对草甸鸟类也很重要。根据我们的结果，