Clark's Nutcracker Predicted Habitat - CWHR B350 [ds2246]

The datasets used in the creation of the predicted Habitat Suitability models includes the CWHR range maps of Californias regularly-occurring vertebrates which were digitized as GIS layers to support the predictions of the CWHR System software. These vector datasets of CWHR range maps are one component of California Wildlife Habitat Relationships (CWHR), a comprehensive information system and predictive model for Californias wildlife. The CWHR System was developed to support habitat conservation and management, land use planning, impact assessment, education, and research involving terrestrial vertebrates in California. CWHR contains information on life history, management status, geographic distribution, and habitat relationships for wildlife species known to occur regularly in California. Range maps represent the maximum, current geographic extent of each species within California. They were originally delineated at a scale of 1:5,000,000 by species-level experts and have gradually been revised at a scale of 1:1,000,000. For more information about CWHR, visit the CWHR webpage (https://www.wildlife.ca.gov/Data/CWHR). The webpage provides links to download CWHR data and user documents such as a look up table of available range maps including species code, species name, and range map revision history; a full set of CWHR GIS data; .pdf files of each range map or species life history accounts; and a User Guide.The models also used the CALFIRE-FRAP compiled "best available" land cover data known as Fveg. This compilation dataset was created as a single data layer, to support the various analyses required for the Forest and Rangeland Assessment, a legislatively mandated function. These data are being updated to support on-going analyses and to prepare for the next FRAP assessment in 2015. An accurate depiction of the spatial distribution of habitat types within California is required for a variety of legislatively-mandated government functions. The California Department of Forestry and Fire Protections CALFIRE Fire and Resource Assessment Program (FRAP), in cooperation with California Department of Fish and Wildlife VegCamp program and extensive use of USDA Forest Service Region 5 Remote Sensing Laboratory (RSL) data, has compiled the "best available" land cover data available for California into a single comprehensive statewide data set. The data span a period from approximately 1990 to 2014. Typically the most current, detailed and consistent data were collected for various regions of the state. Decision rules were developed that controlled which layers were given priority in areas of overlap. Cross-walks were used to compile the various sources into the common classification scheme, the California Wildlife Habitat Relationships (CWHR) system.CWHR range data was used together with the FVEG vegetation maps and CWHR habitat suitability ranks to create Predicted Habitat Suitability maps for species. The Predicted Habitat Suitability maps show the mean habitat suitability score for the species, as defined in CWHR. CWHR defines habitat suitability as NO SUITABILITY (0), LOW (0.33), MEDIUM (0.66), or HIGH (1) for reproduction, cover, and feeding for each species in each habitat stage (habitat type, size, and density combination). The mean is the average of the reproduction, cover, and feeding scores, and can be interpreted as LOW (less than 0.34), MEDIUM (0.34-0.66), and HIGH (greater than 0.66) suitability. Note that habitat suitability ranks were developed based on habitat patch sizes >40 acres in size, and are best interpreted for habitat patches >200 acres in size. The CWHR Predicted Habitat Suitability rasters are named according to the 4 digit alpha-numeric species CWHR ID code. The CWHR Species Lookup Table contains a record for each species including its CWHR ID, scientific name, common name, and range map revision history (available for download at https://www.wildlife.ca.gov/Data/CWHR).

用于构建生境适宜性预测模型的数据集，包含加州常态化分布脊椎动物的CWHR（California Wildlife Habitat Relationships，加州野生生物生境关系）分布范围图。此类分布图已被数字化为地理信息系统（GIS）图层，以支撑CWHR系统软件的预测工作。
该CWHR分布范围图的矢量数据集，是加州野生生物生境关系系统的组成部分之一。CWHR是一套面向加州野生生物的综合性信息系统与预测模型，其开发初衷是为支撑涉及加州陆生脊椎动物的生境保护与管理、土地利用规划、环境影响评价、科普教育及科学研究等工作。CWHR收录了已知在加州常态化分布的野生生物物种的生活史、管理现状、地理分布以及生境关联信息。分布范围图表征了各物种在加州境内当前的最大地理分布范围，最初由物种专家以1:5,000,000的比例尺绘制，后逐步修订为1:1,000,000的比例尺。如需了解CWHR的更多信息，请访问CWHR官方网页（https://www.wildlife.ca.gov/Data/CWHR）。该网页提供了CWHR数据与用户文档的下载链接，包括涵盖物种代码、物种名称及分布范围图修订历史的可用分布图查询表、全套CWHR地理信息系统数据、各分布范围图或物种生活史说明的PDF文件，以及《用户指南》。
本模型同时使用了由CALFIRE-FRAP汇编的“最佳可用”土地覆被数据Fveg，其中CALFIRE即加州森林与消防局，FRAP即火灾与资源评估项目。该汇编数据集被制作为单一数据图层，以支撑《森林与牧场评估》所需的各类分析工作——这是一项由立法强制要求的政府职能。当前该数据集正处于更新阶段，以支撑持续开展的分析工作，并为2015年的下一轮FRAP评估做准备。准确表征加州境内生境类型的空间分布，是多项由立法强制要求的政府职能的必要前提。加州森林与消防局火灾与资源评估项目（FRAP）联合加州鱼类与野生动物局VegCamp项目，并大量使用美国农业部（USDA）林务局第五区遥感实验室（RSL）的数据，将加州境内可获取的“最佳可用”土地覆被数据整合为一套综合性全州范围数据集。该数据集的时间跨度约为1990年至2014年，通常针对加州各区域采集了最新、最详细且一致性最强的数据。研究人员制定了决策规则，用于在图层重叠区域确定优先采用的图层；同时通过统一映射规则将各类源数据整合至统一的分类体系，即加州野生生物生境关系（CWHR）系统。
研究人员将CWHR分布数据与FVEG植被图、CWHR生境适宜性等级相结合，为各物种生成了生境适宜性预测分布图。该分布图展示了该物种的平均生境适宜性得分，其定义遵循CWHR标准。CWHR将生境适宜性按各物种在各生境阶段（生境类型、面积与密度的组合）下的繁殖、栖息与觅食需求划分为四个等级：无适宜性（0分）、低适宜性（0.33分）、中适宜性（0.66分）与高适宜性（1分）。平均得分为繁殖、栖息与觅食得分的平均值，可按以下区间解读：低适宜性（得分低于0.34）、中适宜性（0.34-0.66）与高适宜性（得分高于0.66）。需注意，生境适宜性等级的制定基于面积大于40英亩的生境斑块，其适用的最佳场景为面积大于200英亩的生境斑块。CWHR生境适宜性预测栅格数据的命名遵循4位字母数字混合的CWHR物种ID代码规则。CWHR物种查询表包含各物种的记录，涵盖其CWHR ID、学名、通用名及分布范围图修订历史（可在https://www.wildlife.ca.gov/Data/CWHR下载）。