Populus tremula chorology

Distribution map of Eurasian aspen (Populus tremula)These maps were produced by combining numerous and heterogeneous data collected from atlas monographs providing complete species distribution maps, from national to regional atlases, occurrence geo-databases, scientific and grey literature.The maps were created using ESRI shapefiles (*.shp, *.shx, *.dbf, *.prj files) archived in the ZIP file. Species range is mapped with polygon features (name suffix "plg"), which define continuous areas of occupancy of the species, and with point features (name suffix "pnt"), which identify more fragmented and isolated populations. If synanthropic occurrences are reported outside the species natural range, additional point and/or polygon shapefiles are also present (suffix "syn"). Polygon borders delimiting species ranges are generalized across the mainland and sea boundaries. This offers the possibility to mask sea areas or to clip and extract the terrestrial range parts using GIS data layers of the users' choice. An additional version of polygon ranges are clipped with a coastline (name suffix "clip"), which have been derived from Natural Earth dataset "Admin 0 - Countries" 1:50M version 4.1.0 (https://www.naturalearthdata.com). Please cite as:Caudullo, G., Welk, E., San-Miguel-Ayanz, J., 2017. Chorological maps for the main European woody species. Data in Brief 12, 662-666. DOI: doi.org/10.1016/j.dib.2017.05.007 Additional information and used references are on 'supplementary materials' document:https://doi.org/10.6084/m9.figshare.5091901Chorological maps are part of the "European Atlas of Forest Tree Species" project:https://w3id.org/mtv/FISE-Comm/v01欧洲山杨（Populus tremula）分布格局图。本数据集的分布图由多源异构数据整合制作而成，数据来源包括覆盖全国至区域尺度的完整物种分布图集专题专著、物种出现点地理数据库，以及正式科学文献与灰色文献。所有地图以ESRI形状文件（*.shp, *.shx, *.dbf, *.prj）打包归档于ZIP压缩包内。物种分布范围通过两类要素表征：其一为多边形要素（名称后缀"plg"），用于划定物种的连续栖息区域；其二为点要素（名称后缀"pnt"），用于标识更为破碎孤立的种群。若存在物种自然分布区外的人为伴生出现记录，则将附带额外的点和/或多边形形状文件（后缀"syn"）。物种分布范围的多边形边界已针对大陆与海洋界线进行概化处理，支持使用者通过自定义GIS数据图层掩膜海洋区域，或裁切提取陆域分布范围部分。另有经海岸线裁切的多边形范围版本（名称后缀"clip"），其海岸线数据源自Natural Earth数据集"Admin 0 - Countries"1:50M 4.1.0版（https://www.naturalearthdata.com）。引用格式如下：Caudullo, G., Welk, E., San-Miguel-Ayanz, J., 2017. 欧洲主要木本植物物种分布区图集. Data in Brief 12, 662-666. DOI: doi.org/10.1016/j.dib.2017.05.007。更多补充信息与参考文献详见补充材料文档：https://doi.org/10.6084/m9.figshare.5091901。本分布区图集为"欧洲林木树种图集"项目的组成部分：https://w3id.org/mtv/FISE-Comm/v01