Southern Mountain Yellow-Legged Frog (South CA DPS) Predicted Habitat - CWHR A044b [ds3321]

<div style='text-align:Left;'><div><div><p><span>CWHR Predicted Habitat Models represent areas of predicted suitable habitat for each species within its range. These models are built from the following principal inputs: </span></p><p><span>1) a statewide, best-available vegetation map (FVEG); </span></p><p><span>2) GIS data representing a species’ range; </span></p><p><span>3) the CWHR database of habitat suitability values for over 700 terrestrial vertebrate species. </span></p><p><span>Habitat suitability ranks of Low (non-zero values less than 0.34), Medium (0.34-0.66), and High (greater than 0.66) are based on the maximum suitability value across the 3 species life requisites: reproduction, feeding, and cover. Note that previous versions of these Predicted Habitat Models used an average across the 3 life requisites in order to obtain an overall suitability score for each habitat type and stage class. Habitat suitability scores were developed based on habitat patch sizes greater than 40 acres in size and are best interpreted for habitat patches greater than 200 acres in size. The FVEG landcover dataset is an aggregation of multiple statewide landcover and regional vegetation mapping efforts, conducted at different points in time (approximately 1990 up to time of publishing) and at various resolutions, compiled by the California Department of Forestry and Fire Protection (CALFIRE). FVEG uses the most current and consistent data available for each region of the state. Decision rules were developed that controlled which layers were given priority in areas of overlap. Crosswalks were used to attribute the various data sources according to the CWHR habitat-type classification system. Attributing FVEG with CWHR habitat types allows for the extraction of areas with non-zero suitability values for each species within the bounds of its range, creating a series of maps of predicted suitable habitat which are species-specific. Because FVEG is an amalgam of disparate landcover assessment efforts across the state, the predictive power for determining suitable habitat will vary between species, and possibly even regionally for species which are widely distributed. While these maps represent CDFW’s best estimate of the presence of suitable habitat for any given species in the CWHR system, these maps are also limited by several factors: 1) the accuracy and resolution of vegetation maps in a given region; 2) the dynamic nature of the landscape in which fire and other disturbance events alter conditions at a greater frequency than mapping efforts can track; 3) the currency of expert knowledge, particularly as species adapt to changing land and climate conditions and the shifting of other species’ ranges; 4) the frequency of species-specific surveys across a representative sample of a species’ entire range; 5) metapopulation dynamics, which describes the shifting of populations within their environment as result of numerous types of interactions and responses. </span></p><p><span>CWHR GIS data representing predicted suitable habitat should not be used to indicate the presence or absence of a particular species at any specific site. CWHR predicted habitat models are named according to the 4-character alpha-numeric CWHR ID assigned to each species (5 characters in the case of subspecies or other sub-taxa). There is also a “CWHR Revision Tracking Table” containing a record for each species, its CWHR ID, scientific name, common name, and range and habitat model data revision history. CWHR species range models, predicted habitat models, and GIS data of the statewide distribution of all CWHR habitat types, along with the CWHR revision tracking table, are available for download at </span><a href='https://www.wildlife.ca.gov/Data/CWHR' target='_blank' style='text-decoration:underline;' rel='nofollow ugc noopener noreferrer'><span>https://www.wildlife.ca.gov/Data/CWHR</span></a><span>. </span></p></div></div></div>

<p><span>CWHR预测生境模型（CWHR Predicted Habitat Models）代表了各物种在其分布范围内的潜在适宜生境区域。此类模型基于以下核心输入项构建：</span></p><p><span>1) 全州范围内可获取的最优植被地图（FVEG）；</span></p><p><span>2) 代表物种分布范围的地理信息系统（GIS）数据；</span></p><p><span>3) 涵盖700余种陆生脊椎动物生境适宜性分值的CWHR数据库。</span></p><p><span>生境适宜性等级划分为低（非零分值小于0.34）、中（0.34~0.66）和高（大于0.66），该划分基于物种3项生存必需条件——繁殖、觅食与隐蔽——对应的适宜性分值的最大值。需注意，此前版本的此类预测生境模型曾通过计算3项生存必需条件的平均分值，来获取每种生境类型与演替阶段的综合适宜性评分。生境适宜性评分基于面积大于40英亩的生境斑块制定，其解释效力在面积大于200英亩的生境斑块中最优。</span></p><p><span>FVEG土地覆盖数据集由加州林业与消防局（California Department of Forestry and Fire Protection, CALFIRE）汇编而成，整合了多次全州范围及区域尺度的植被测绘工作成果，这些测绘工作于不同时间（大致为1990年至发布时）开展，且分辨率各异。FVEG针对全州各区域采用当前可获取的最新且一致的数据。研究制定了决策规则，用于确定重叠区域内各数据图层的优先级。通过属性转换对照表（Crosswalks），依据CWHR生境类型分类系统对各类数据源进行属性赋值。将FVEG数据赋予CWHR生境类型属性后，即可在各物种的分布范围内提取出具有非零适宜性分值的区域，从而生成一系列针对特定物种的预测适宜生境地图。</span></p><p><span>由于FVEG是全州范围内不同土地覆盖评估工作的整合成果，因此其在确定适宜生境方面的预测能力会因物种而异，对于分布广泛的物种，其预测能力甚至可能因区域不同而存在差异。尽管此类地图代表了加州鱼类与野生动物部（California Department of Fish and Wildlife, CDFW）对CWHR体系中各物种适宜生境存在情况的最优估算，但这些地图仍受以下若干因素限制：1）特定区域内植被地图的精度与分辨率；2）景观的动态性：火灾与其他干扰事件改变生境条件的频率高于测绘工作的追踪速率；3）专家知识的时效性：尤其是在物种适应土地与气候条件变化、以及其他物种分布范围发生转移的背景下；4）针对物种全分布范围的代表性样地开展物种专项调查的频次；5）集合种群动态（metapopulation dynamics）：该概念描述了种群因各类相互作用与响应而在其生存环境中发生的位移变化。</span></p><p><span>代表预测适宜生境的CWHR地理信息系统数据不得用于判定某一特定地点是否存在某一物种。CWHR预测生境模型的命名依据为分配给各物种的4位字母数字混合CWHR标识符（亚种或其他亚类群的标识符为5位）。此外还设有“CWHR修订追踪表”，其中包含各物种的相关记录，包括其CWHR标识符、学名、通用名、分布范围以及生境模型数据的修订历史。CWHR物种分布模型、预测生境模型、涵盖所有CWHR生境类型全州分布的地理信息系统数据，以及CWHR修订追踪表，均可从以下网址下载：<a href='https://www.wildlife.ca.gov/Data/CWHR' target='_blank' style='text-decoration:underline;' rel='nofollow ugc noopener noreferrer'><span>https://www.wildlife.ca.gov/Data/CWHR</span></a>。</span></p>