A landscape approach to conserving wetland bird habitat in the Prairie Pothole Region of eastern South Dakota
A landscape approach to conserving wetland bird habitat in the Prairie Pothole Region of eastern South Dakota
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保护南达科他州东部草原坑洼地区湿地鸟类栖息地的景观方法
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发表时间：
2000
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通讯作者：
K. F. Higgins
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作者：
D. Naugle;Rex R. Johnson;Michael E. Estey;K. F. Higgins
资源管理者面临着在破碎景观中保护草原湿地鸟类生态系统的问题，需要进行景观研究，以指导在广泛地理区域内的保护工作。通过将遥感湿地和土地覆盖数据与湿地鸟类栖息地模型相结合，研究了局地和景观因素对生境适宜性的影响。我们将栖息地模型与地役权和收费湿地的位置联系起来，以评估受保护的适宜栖息地的空间位置和范围。我们还模拟了小湿地的消失对使用多个湿地的流动物种的大湿地适宜性的影响。最后，我们评估了水禽栖息地规划在保护非名目湿地鸟类栖息地方面的效果，以推荐最大化区域景观连通性的策略。为本研究构建的区域数据库表明，美国南达科他州东部的地役权和收费地役权覆盖了13.9%（120万公顷）的土地面积，保护了19.8%的湿地。受保护的湿地比例最高的是半永久性湿地（32.3%），中等的是季节性湿地（25.6%），最低的是临时湿地（15.8%）。采用分层两阶段聚类抽样方法，随机选择1995年和1996年调查的834个半永久性和季节性湿地进行鸟类调查。Logistic分析表明，一些物种（如维吉那州秧鸡、嘴嘴鹭）的栖息地适宜性与湿地内的当地植被条件有关，而另一些物种（如北方尖尾鸟、黑燕鸥）的适宜性与更大尺度的景观结构有关。因此，未破碎化的草原湿地景观（即在高地草原中嵌入湿地复合体的地区）比在农田中孤立的湿地为更多的物种提供了栖息地。利用调查湿地开发的模型对南达科他州东部所有半永久性和季节性湿地的生境适宜性进行了分类。小湿地是影响大湿地生境适宜性的周边景观的重要组成部分。小型湿地（<0.5 ha）消失后，用于对大型剩余湿地适宜性进行重新分类的模型表明，最易受小型湿地损失影响的物种是在大空间尺度上开发资源的脆弱物种。当<0.5 ha的湿地被移除时，适合北方尖尾鱼的湿地数量减少了20.7%。北方尖尾鱼是一种在一个季节内使用多个湿地的流动物种。水禽栖息地保护工作的历史范例也保护了非名鸟物种的栖息地。认识到小型浅水湿地对水禽繁殖的重要性的现代范例已经将保护的重点转移到保护占据更丰富的季节性湿地的物种的栖息地上。停止保护工作将导致区域湿地景观进一步破碎化。我们建议，获取湿地不仅是为了巩固核心保护区内适宜的栖息地，而且要确保核心保护区之间的联结，以保持区域湿地景观之间的连通性。
Resource managers confronted with preserving ecosystems for prairie wetland birds in fragmented landscapes require landscape studies that direct conservation efforts over broad geographic regions. We investigated the role of local and landscape factors affecting habitat suitability by integrating remotely sensed wetland and land-cover data with wetland bird habitat models. We linked habitat models with locations of easement and fee-title wetlands to evaluate spatial location and extent of protected, suitable habitat. We also simulated impacts of the loss of small wetlands on suitability of larger wetlands for mobile species that use multiple wetlands. Lastly, we evaluated the efficacy of waterfowl habitat programs in preserving suitable habitat for nongame wetland bird species to recommend strategies for maximizing regional landscape connectivity. Regional databases constructed for this study indicate that easement and fee-title tracts encompass 13.9% (1.2 million ha) of land area and protect 19.8% of the wetlands in eastern South Dakota, USA Proportion of protected wetlands is highest for semi-permanent (32.3%), intermediate for seasonal (25.6%), and lowest for temporary wetlands (15.8%). A stratified, two-stage cluster sample was used to randomly select 834 semi-permanent and seasonal wetlands that were surveyed for birds in 1995 and 1996. Logistic analyses indicate that habitat suitability for some species (e.g., Virginia rail, pied-billed grebe) is related to local vegetation conditions within wetlands, while suitability for others (e.g., northern pintail, black tern) is related to landscape structure at larger scales. As a result, unfragmented prairie wetland landscapes (i.e., areas with wetland complexes embedded within upland grasslands) provide habitat for more species than isolated wetlands in tillage fields. Models developed from survey wetlands were used to classify habitat suitability for all semi-permanent and seasonal wetlands in eastern South Dakota. Small wetlands are critical components of the surrounding landscape that influence habitat suitability of larger wetlands. Models used to reclassify suitability of larger remaining wetlands after small wetlands (<0.5 ha) were removed indicate that species most vulnerable to loss of small wetlands are vagile species that exploit resources over broad spatial scales. Number of wetlands suitable for northern pintails, a mobile species that uses multiple wetlands within a season, decreased 20.7% when wetlands <0.5 ha were removed. Historic paradigms dictating waterfowl habitat protection efforts also have conserved habitat for nongame bird species. Modern paradigms that acknowledge the importance of small shallow wetlands to breeding waterfowl have shifted the focus of protection towards preserving habitat for species that occupy more abundant seasonal wetlands. Cessation of protection efforts would result in further fragmentation of regional wetland landscapes. We recommend that wetlands be acquired not only to consolidate suitable habitat within protected core areas but also to ensure that core areas coalesce to preserve connectivity among regional wetland landscapes.