Waterbird responses to experimental drawdown: implications for the multispecies management of wetland mosaics
Waterbird responses to experimental drawdown: implications for the multispecies management of wetland mosaics
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DOI：
10.1046/j.1365-2664.2002.00763.x
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发表时间：
2002-12-01
影响因子：
5.7
通讯作者：
Safran, RJ
中科院分区：
文献类型：
--
作者：
Taft, OW;Colwell, MA;Safran, RJ
1.全球湿地的丧失和人为改变强调了有效管理的重要性。对于为非繁殖水鸟提供栖息地的湿地，这种管理通常旨在支持丰富和丰富的水鸟社区。在世界上许多季节性的湿地中，每年冬天的洪水之后是春天的降水，以鼓励水禽食物植物的发芽。关于如何最好地为多个物种维持淹没湿地的建议大多是理论上的，而缩编管理通常侧重于春季迁徙的滨鸟。冬季浅水管理的利弊尚未得到研究，特别是在相当大的越冬水鸟和水鸟种群一起出现的地方。我们认为，草原生态区在加州的中央谷，美国，作为一个模型湿地复合体，以评估最佳的冬季洪水深度多物种使用。我们还研究了每个水鸟组的相对效益（e。G.滨鸟和水禽）的下降进行了冬季和春季。我们在1994-95年的冬季和春季对测量地形的湿地进行了实验性脱水，记录了水鸟物种丰富度和丰度的变化，这些变化与栖息地多样性和可用性的日常变化有关。结果表明，有限的区域提供的浅水栖息地在整个景观在冬季，但不是春季，作为使用的滨鸟和水鸭在冬季下降的湿地增加。在两个季节的消退后期，深水鸭子和潜水水鸟的使用量有所下降，但直到滨鸟和水鸭的使用量达到顶峰。在地形梯度为30-40 cm的湿地上，水鸟的最大多样性和丰度出现在平均深度为10-20 cm处。这项研究具有重要的意义，冬季管理的季节性湿地复合体，特别是湿地土壤系统的管理人员提供栖息地的不同水鸟群体（从滨鸟潜水水鸟）同时。一般来说，地形是可变的（e。G.最深和最浅区域之间的差异为30-40厘米），平均深度为15-20厘米的湿地应能容纳最丰富的水鸟。
1. The loss and human modification of wetlands world-wide underscores the importance of efficient management. For wetlands that provide habitats for non-breeding waterbirds, such management often aims to support a rich and abundant waterbird community.2. Among the world's many seasonal, moist-soil managed wetlands, annual winter flooding is followed by spring drawdown to encourage germination of waterfowl food plants. Recommendations on how best to maintain flooded wetlands for multiple species are mostly theoretical, and drawdown management typically focuses on spring for migrating shorebirds. The benefits and drawbacks of shallow-water management in winter have not been examined, especially where sizeable populations of wintering shorebirds and waterfowl occur together.3. We considered The Grasslands Ecological Area in California's Central Valley, USA, as a model wetland complex in which to assess optimal winter flood-depth for multispecies use. We also examined the relative benefits for each waterbird group (e. g. shorebirds and waterfowl) of drawdowns conducted in winter and spring. We experimentally dewatered wetlands of measured topography in the winter and spring of 1994-95, documenting changes in waterbird species richness and abundance associated with daily changes in habitat diversity and availability.4. Results indicated limited regional availability of shallow-water habitat across the landscape in winter but not spring, as use by shorebirds and teal increased on drawn-down wetlands in winter only. Use by deeper-water dabbling ducks and diving waterbirds declined during the later stages of drawdown in both seasons, but not until use by shorebirds and teal had peaked. The maximum diversity and abundance of waterbirds occurred at average depths of 10-20 cm on wetlands with topographic gradients of 30-40 cm.5. This study has important implications for the winter management of seasonal wetland complexes, especially moist-soil systems where managers provide habitat for different waterbird groups (from shorebirds to diving waterbirds) simultaneously. In general, where topography is variable (e. g. a difference of 30-40 cm between the deepest and shallowest zones), wetlands flooded to average depths of 15-20 cm should accommodate the greatest richness and abundance of waterbirds.