Prepared species distributions

Raster layers representing 31 species/population distributions that were prepared for: Johnson, C.A., Drever, R., Kirby, P. Neave, E. and Martin, A. E. Protecting boreal caribou habitat can help conserve biodiversity and safeguard large quantities of soil carbon in Canada See <strong>Read_me.pdf</strong> for full description. These prepared distributions were later combined with select distributions from the ‘Range map extents, species at risk, Canada’ dataset (ECCC, 2016) to estimate species richness, taxonomic diversity, and presence of species considered to be unique to the boreal caribou distribution. Most of the prepared distributions, provided here, were based on georeferencing maps/figures in status reports and hand digitizing the distribution. Others are based on assembling National Hydro Network work units to re-create distributions in status reports. Some distributions are based on convex hull generation around map features, similar to extent of occurrence boundaries. For hand digitized distributions, rather than tracing all shorelines, islands, administrative boundaries, or other features, some supplementary layers from the Atlas of Canada data sets were used (see Read_me.pdf: ‘Supporting layers, used in species distribution preparation’ section for layers used). <strong>NOTE</strong>: These distributions are not official representations of any given species or population. Many were heavily generalized in the source maps. Additional spatial error was introduced during map georeferencing and digitizing. <br> <br>

本数据集包含代表31个物种种群分布的栅格图层（raster layers），系为以下研究制作：Johnson, C.A.、Drever, R.、Kirby, P.、Neave, E.及Martin, A. E. 撰写的《保护加拿大北方驯鹿（boreal caribou）栖息地可助力生物多样性保护与土壤碳固存》。完整说明请参见<strong>"Read_me.pdf"</strong>。

后续将本数据集生成的物种分布图层，与"加拿大濒危物种分布范围数据集"（ECCC，2016）中的精选分布图层相结合，用以估算物种丰富度（species richness）、分类多样性（taxonomic diversity），以及仅分布于北方驯鹿分布区内的特有物种存在情况。

本次提供的多数分布图层，基于现状报告中的地图/图件经地理配准（georeferencing）后手动矢量化（hand digitizing）得到；其余图层则通过整合加拿大国家水文网络工作单元，重现了现状报告中的物种分布范围。部分分布图层则基于地图要素生成凸包（convex hull），其处理方式与实际出现范围边界的构建逻辑一致。

对于手动矢量化的分布图层，本次未逐一追踪海岸线、岛屿、行政边界或其他地理要素，而是使用了加拿大地图集数据集的补充图层（相关使用图层详情请参见<strong>"Read_me.pdf"</strong>中"物种分布制备所用支撑图层"章节）。

<strong>注意</strong>：本数据集的分布图层并非任一物种或种群的官方代表范围。多数图层在源地图中已进行了大幅简化，且在地图地理配准与矢量化过程中引入了额外的空间误差。