Playas (Southeast Blueprint Indicator)
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Reason for Selection The unique wet-dry cycle that characterizes this important wetland ecosystem makes playas a biodiversity hotspot within the Great Plains. Playas support a rich community of wetland plants and invertebrates, providing habitat and food for migrating waterfowl, shorebirds, and resident prairie birds, as well as many mammal and amphibian species. Healthy playas “provide a sustainable water source for communities and rain-fed operations, water filtration, flood control, livestock forage, and recreation” (PLJV 2022). They play a particularly critical role in groundwater recharge and filtration that improve the quantity and quality of water in the region’s aquifers. Sediment accumulation due to agriculture in and around playas, as well as modification from construction and hydrologic alteration, have significantly degraded and continue to threaten the habitat and ecosystem services that playas provide (PLJV website). Input Data Base Blueprint 2022 extent Playa Lakes Joint Venture probable playas dataset v5, accessed 5-25-2022 This dataset is a regional compilation of several data sources including the National Wetlands Inventory, Soil Survey Geographic database, and satellite imagery. Specific details on methods are in the release notes. This dataset defines a healthy playa as one that is not farmed, has no hydrological modifications, is not within a wind farm, and is not sedimented. It defines playa clusters by identifying areas with either high playa density or high playa surface area, according to duck abundance data collected on playas. Playa Lakes Joint Venture (JV) boundary extracted from the North American Joint Venture Boundary dataset Southeast Blueprint 2023 extent Mapping Steps From the Playa Lakes JV probable playas v5 data, convert polygons to raster and use the fields “healthy” and “cluster” to identify healthy playas and those that are part of a larger cluster. Assign zero values to all pixels not identified as a playa above. Zero values are intended to help users better understand the extent of this indicator and make it perform better in online tools. Convert the Playa Lakes JV boundary to raster, giving it a value of 1. Limit the playas data (values of 0, 1, 2, and 3) to the Playa Lakes JV boundary by taking the playa raster times the JV raster. Clip to the spatial extent of Base Blueprint 2022. As a final step, clip to the spatial extent of Southeast Blueprint 2023. Note: For more details on the mapping steps, code used to create this layer is available in the Southeast Blueprint Data Download under > 6_Code. Final indicator values Indicator values are assigned as follows: 3 = Healthy playa and part of a larger cluster 2 = Healthy playa 1 = Other playa 0 = Not identified as a playa Known Issues This indicator underrepresents playas, especially those smaller than 2 acres, in the eastern half of Beaver, Oklahoma. NWI data were missing from that area and the additional data sources used tend to underestimate playas, especially those less than 2 acres in size. Disclaimer: Comparing with Older Indicator Versions There are numerous problems with using Southeast Blueprint indicators for change analysis. Please consult Blueprint staff if you would like to do this (email hilary_morris@fws.gov). Literature Cited Playa Lakes Joint Venture. Playas of the high plains: Providing water for wildlife and people. [https://pljv.org/docs/What_Are_Playas.pdf]. Playa Lakes Joint Venture probable playas dataset v5. Playa Lakes Joint Venture. Accessed May 25, 2022. [https://pljv.org/playas/playa-tools/]. Playa Lakes Joint Venture website. 2022. Playas Benefit Wildlife and People. [https://pljv.org/playas/]. U.S. Fish and Wildlife Service. FWS Migratory Bird North American Joint Ventures Boundaries. [https://gis-fws.opendata.arcgis.com/datasets/d34bd6ebd33543d68a00fc7d412890fa_0/about].
选择依据 本数据集所依托的独特干湿循环特征，使普拉亚湿地（playa）成为大平原地区极具代表性的湿地生态系统与生物多样性热点区域。普拉亚湿地孕育了丰富的湿地植物与无脊椎动物群落，为迁徙水禽、滨鸟、居留草原鸟类以及诸多哺乳类和两栖类物种提供栖息场所与食物来源。健康的普拉亚湿地“可为社区与雨养农业提供可持续水源、实现水体净化、调控洪水、作为畜牧饲草场地并提供休闲场所”（PLJV 2022）。其在地下水补给与过滤方面发挥着尤为关键的作用，能够改善区域含水层的水量与水质。然而，普拉亚湿地及其周边因农业活动导致的沉积物堆积，以及工程建设与水文改造带来的干扰，已对普拉亚湿地所能提供的栖息地与生态系统服务造成严重破坏，并持续构成威胁（PLJV 官网）。 2022年基础蓝图数据集范围 本数据集基于2022年5月25日获取的《普拉亚湖联合倡议（Playa Lakes Joint Venture, PLJV）疑似普拉亚湿地数据集v5》制作，整合了包括国家湿地清单（National Wetlands Inventory, NWI）、土壤调查地理数据库（Soil Survey Geographic database）与卫星影像在内的多源区域数据。具体方法细节详见发布说明。 该数据集将健康普拉亚湿地定义为未被耕作、未经历水文改造、不在风电场范围内且未发生沉积物淤积的湿地。其通过结合基于普拉亚湿地观测的鸭类丰度数据，以高普拉亚湿地密度或高普拉亚湿地表面积为标准，划定普拉亚湿地集群。 普拉亚湖联合倡议边界数据源自北美联合倡议边界数据集。 2023年东南蓝图范围 制图流程 1. 从PLJV疑似普拉亚湿地v5数据中，将矢量多边形转换为栅格，并利用字段“healthy”（健康属性）与“cluster”（集群属性）识别健康普拉亚湿地及隶属于更大集群的普拉亚湿地。 2. 为所有未被识别为普拉亚湿地的像素赋值为0，以帮助用户更清晰地了解该指标的覆盖范围，并提升其在在线工具中的运行性能。 3. 将PLJV边界转换为栅格，赋值为1。 4. 通过将普拉亚湿地栅格与PLJV边界栅格相乘，将普拉亚湿地数据（取值为0、1、2、3）限定在PLJV边界范围内。 5. 裁剪至2022年基础蓝图的空间范围。 6. 最后，裁剪至2023年东南蓝图的空间范围。 注：有关制图步骤的更多细节，可在“东南蓝图数据下载”的“6_Code”路径下获取用于生成该图层的代码。 最终指标取值规则 指标赋值规则如下： 3 = 健康普拉亚湿地且隶属于更大集群 2 = 健康普拉亚湿地 1 = 其他普拉亚湿地 0 = 未被识别为普拉亚湿地 已知问题 本指标对普拉亚湿地的覆盖存在低估情况，尤其是在俄克拉荷马州比弗县东部区域，该区域缺失国家湿地清单（NWI）数据，且所使用的补充数据源往往会低估面积小于2英亩的普拉亚湿地。 关于与旧版指标对比的免责声明 使用东南蓝图指标进行变化分析存在诸多问题。若需开展此类工作，请咨询蓝图项目工作人员（邮箱：hilary_morris@fws.gov）。 参考文献 1. 普拉亚湖联合倡议. 大平原地区的普拉亚湿地：为野生生物与人类供水. [https://pljv.org/docs/What_Are_Playas.pdf] 2. 普拉亚湖联合倡议疑似普拉亚湿地数据集v5. 普拉亚湖联合倡议. 2022年5月25日获取. [https://pljv.org/playas/playa-tools/] 3. 普拉亚湖联合倡议官网. 2022. 普拉亚湿地惠及野生生物与人类. [https://pljv.org/playas/] 4. 美国鱼类和野生动物管理局（U.S. Fish and Wildlife Service, FWS）. FWS迁徙鸟类北美联合倡议边界数据集. [https://gis-fws.opendata.arcgis.com/datasets/d34bd6ebd33543d68a00fc7d412890fa_0/about]
