Climatic niche data for presences and pseudo-absences of four desert plant species

Presence data for four plant species (<em>Bromus rubens</em>, <em>Layia platyglossa</em>, <em>Phacelia tanacetifolia</em>, and <em>Salvia columbariae</em>) scraped from the Global Biodiversity Information Facility for a section of Southern California along with matching climatic data from WorldClim. Pseudo absences were randomly selected within the same extent as the presence data (latitude: 35.28531- 36.56198; longitude: -120.2184- -116.7162) using the biomod2 package in R. WorldClim version 2.1 climate data was extracted at a resolution of 0.5 minutes (~1 km2) and pseudo absences were selected from the raster pixels not containing any presences. The number of pseudo absences selected was based on three times the number of presences for each species. All temperatures are in degrees Celsius. <br> Data Headings: long = longitude lat = latitude ops_type = whether obersavation is a true presence or psuedo absence species = plant species presence = 1 for presence, 0 for absence bio1 = Mean annual temperature bio2 = Mean diurnal range (mean of max temp - min temp) bio3 = Isothermality (bio2/bio7) (* 100) bio4 = Temperature seasonality (standard deviation *100) bio5 = Max temperature of warmest month bio6 = Min temperature of coldest month bio7 = Temperature annual range (bio5-bio6) bio8 = Mean temperature of the wettest quarter bio9 = Mean temperature of driest quarter bio10 = Mean temperature of warmest quarter bio11 = Mean temperature of coldest quarter bio12 = Total (annual) precipitation bio13 = Precipitation of wettest month bio14 = Precipitation of driest month bio15 = Precipitation seasonality (coefficient of variation) bio16 = Precipitation of wettest quarter bio17 = Precipitation of driest quarter bio18 = Precipitation of warmest quarter bio19 = Precipitation of coldest quarter

本数据集包含4种植物（<em>Bromus rubens</em>、<em>Layia platyglossa</em>、<em>Phacelia tanacetifolia</em>、<em>Salvia columbariae</em>）的分布记录数据，爬取自全球生物多样性信息设施（Global Biodiversity Information Facility），覆盖美国加利福尼亚南部区域，同时配套了与该分布区域匹配的世界气候数据集（WorldClim）气候数据。

本数据集通过R语言的biomod2包，在与真实分布记录相同的空间范围（纬度：35.28531~36.56198；经度：-120.2184~-116.7162）内，随机选取伪缺席样本（pseudo absences）。所用世界气候数据集版本为2.1，气候数据提取分辨率为0.5角分（约1平方千米），伪缺席样本仅从未包含任何真实分布记录的栅格像素中选取，且每个物种对应的伪缺席样本数量为其真实分布记录数的3倍。所有温度单位均为摄氏度（℃）。

数据字段说明如下：
long：经度（longitude）；lat：纬度（latitude）；ops_type：用于标注观测为真实分布记录还是伪缺席样本；species：植物物种名称；presence：取值为1时代表真实分布记录，取值为0时代表伪缺席样本；
bio1：年平均温度；
bio2：昼夜温差范围（最高温与最低温的均值差）；
bio3：等温性（bio2/bio7 ×100）；
bio4：温度季节性（标准差×100）；
bio5：最热月最高温；
bio6：最冷月最低温；
bio7：年温度极差（bio5-bio6）；
bio8：湿季平均温度；
bio9：干季平均温度；
bio10：暖季平均温度；
bio11：冷季平均温度；
bio12：年总降水量；
bio13：最湿月降水量；
bio14：最干月降水量；
bio15：降水季节性（变异系数）；
bio16：湿季降水量；
bio17：干季降水量；
bio18：暖季降水量；
bio19：冷季降水量。