Lichen abundance on two tree species

Lichen_Names.csv: this is a csv file (34 rows, 2 columns), with a header line. The first column is lichen species scientific names. Species names are as listed in the most recent Checklist of North American Lichen (Esslinger 2019). The second column is the species codes as used in the associated manuscript. bF_abundanceTreeLevel.csv: this is a csv file (21 rows, 26 columns, with a header line). The data describe lichen abundance on 21 balsam fir (Abies balsamea) trees in the Central Avalon Ecoregion, island of Newfoundland, Canada. The first column is the TreeID. The remaining columns list the abundance (number of individual thalli) of each species found on each tree. Associated species names for each code are found in the Lichen_Names.csv file yB_abundanceTreeLevel.csv: this is a csv file (21 rows, 31columns, with a header line). The data describe lichen abundance on 21 yellow birch (Betula alleghaniensis) trees in the Central Avalon Ecoregion, island of Newfoundland, Canada. The first column is the TreeID. The remaining columns list the abundance (number of individual thalli) of each species found on each tree. Associated species names for each code are found in the Lichen_Names.csv file. TreeSiteData_BF.csv: this is a csv file (21 rows, 16 columns, with a header file). The data are the tree-and site level data for the 21 balsam fir (Abies balsamea) trees. TreeSiteData_YB.csv: this is a csv file (21 rows, 16 columns, with a header file). The data are the tree-and site level data for the 21 balsam fir (Betula alleghaniensis) trees. For the two “TreeSiteData” files, the column details are as follows · TreeID: The treeID number (same as in the lichen abundance datasets) · Texture: a categorical variable that ranks the bark texture from 1-3 (1 is relatively smooth, 2 is moderately ridged, 3 is deeply and heavily ridged) · Canopy1: This is the canopy cover (percent cover) at the tree base measured using a spherical densiometer · Height: This is the height of the tree, in metres, measured using a Suunto Clinometer · pH: This is the bark pH, measured following the procedure outlined in the manuscript · Age: The is the age of the tree, as measured using an increment borer · Age_AG: The age of the tree as measured by a second technician who checked the tree cores · Slope: This is the slope (percent) of the plot taken at the centre of the plot, measured with a Suunto clinometer · Positon: These are categorical values to describe the slope positon on which the tree is found on; 1: upper slope, 2: mid slope, 3: lower slope, 4: toe, or 5: level. · Aspect: Compass aspect (0-360°) adjusted for declination at which the slope faces · Adj_aspect: Compass aspect adjusted to absolute from North (values 0-180°) · Cardinal: The cardinal direction of the slope face (taken from Aspect) but adjusted as categorical data; 1: north, 2: northeast, 3: east, 4: southeast, 5: south, 6: southwest, 7: west, 8 northwest. · Distance: Distance between the two trees at the site. · Canopy2: Average canopy density taken at the centre of the site (mid-way point between the two tree species sampled · Density: Stem density in the stand, measured using the point-quarter method, as outlined in the methods section of the manuscript.

Lichen_Names.csv：该文件为逗号分隔值（CSV）文件，共34行、2列，包含表头行。第一列为地衣物种的学名，所有物种名称均采用最新版《北美地衣名录》（Esslinger 2019）中的记载；第二列为关联研究论文中使用的物种代码。
bF_abundanceTreeLevel.csv：该文件为CSV文件，共21行、26列，包含表头行。数据集记录了加拿大纽芬兰岛中央阿瓦隆生态区21株香脂冷杉（*Abies balsamea*）上的地衣丰度情况。第一列为树木编号（TreeID），其余列分别列出每株树木上检出的各物种的个体地衣体（thallus）数量；各代码对应的物种学名可在Lichen_Names.csv文件中查询。
yB_abundanceTreeLevel.csv：该文件为CSV文件，共21行、31列，包含表头行。数据集记录了加拿大纽芬兰岛中央阿瓦隆生态区21株黄桦（*Betula alleghaniensis*）上的地衣丰度情况。第一列为树木编号（TreeID），其余列分别列出每株树木上检出的各物种的个体地衣体数量；各代码对应的物种学名可在Lichen_Names.csv文件中查询。
TreeSiteData_BF.csv：该文件为CSV文件，共21行、16列，包含表头行。数据集包含上述21株香脂冷杉的树木及样地水平的相关数据。
TreeSiteData_YB.csv：该文件为CSV文件，共21行、16列，包含表头行。数据集包含上述21株黄桦的树木及样地水平的相关数据。
两个“TreeSiteData”数据集的列详细说明如下：
1. TreeID：树木编号，与地衣丰度数据集内的编号一致
2. Texture：树皮纹理等级分类变量，取值范围为1~3（1代表相对光滑，2代表中等褶皱，3代表深且密集的褶皱）
3. Canopy1：使用球面密度仪测定的树木基部冠层盖度（百分比）
4. Height：使用Suunto测高仪测定的树高，单位为米
5. pH：树皮pH值，测定方法遵循研究论文中记载的操作流程
6. Age：通过树木钻芯器（increment borer）获取树芯后测定的树木树龄
7. Age_AG：由第二名技术人员复检树芯后得到的树木树龄
8. Slope：样地中心处的坡度（百分比），采用Suunto测高仪测定
9. Positon：描述树木所处坡度位置的分类变量，取值对应如下：1为上坡位，2为中坡位，3为下坡位，4为坡趾，5为平坡
10. Aspect：经磁偏角校正后的坡向罗盘方位角（0~360°）
11. Adj_aspect：校正为以北为基准的绝对方位角（取值范围0~180°）
12. Cardinal：由Aspect转换得到的坡向方位分类变量，对应关系为：1为北，2为东北，3为东，4为东南，5为南，6为西南，7为西，8为西北
13. Distance：样地内两棵目标树木之间的距离
14. Canopy2：在样地中心（两种目标树种采样点的中点）测定的平均冠层密度
15. Density：林分茎干密度，采用研究论文方法部分记载的点四分法测定。