Settlement Trees, Wisconsin Level 0

We provide a Level 0 record of trees in Wisconsin transcribed from Public Land Surveys conducted by surveyors from the General Land Office of the United States in the 1800s. Posts were set every half mile in townships that were typically 6 miles by 6 miles square. Surveyors recorded details about the one to four trees closest (but typically recorded information for the two closest trees) to the posts and included information about the tree name (taxonomic specificity ranged by surveyor), tree diameter (inches), and distance and bearing from the post. Our records include the tree information and the location of the posts from which the tree information came from. These Level 0 tree data were aggregated to the 8km grid resolution Level 1 product (see msb-paleon.26 package). That product was then statistically smoothed using a statistical model that accounts for zero-inflated continuous data with smoothing based on generalized additive modeling techniques and approximate Bayesian uncertainty estimates for the Level 2 products estimating aboveground biomass (msb-paleon.23), density (msb-paleon.24), and basal area (msb-paleon.25). The data processing steps and associated code are available in the GitHub repository: https://github.com/PalEON-Project/PLS_products. These products are used in the manucript, Paciorek et al., 2020, Statistically-estimated tree biomass, stem, and basal area for the upper Midwestern United States at the time of Euro-American settlement (https://www.biorxiv.org/content/10.1101/856526v1). This material is based upon work supported by the National Science Foundation under grants #DEB-1241874, 1241868, 1241870, 1241851, 1241891, 1241846, 1241856, 1241930.

本数据集提供美国19世纪时期由美国总土地局（General Land Office）测绘人员开展的公共土地调查所转录的威斯康星州树木0级（Level 0）记录。此次公共土地调查的镇区通常为6英里见方的正方形区域，区内每半英里设置一根标杆。测绘人员会记录标杆周边1至4棵（通常记录最靠近的2棵）树木的相关信息，包括树木名称（分类学精度因测绘人员而异）、胸径（单位：英寸），以及该树木相对于标杆的距离与方位角。本数据集收录上述树木信息及对应标杆的位置坐标。上述0级树木数据被聚合为8km网格分辨率的1级（Level 1）产品（详见msb-paleon.26数据包）。随后，针对该1级产品，研究人员采用适配零膨胀连续数据的统计模型进行平滑处理（平滑方法基于广义加性模型（Generalized Additive Model, GAM）技术），并通过近似贝叶斯不确定性估计生成2级（Level 2）产品，包括地上生物量（msb-paleon.23）、树木密度（msb-paleon.24）与断面积（msb-paleon.25）。本数据集的处理流程及配套代码可从GitHub仓库获取：https://github.com/PalEON-Project/PLS_products。上述数据集产品已应用于Paciorek等人2020年发表的论文《欧美殖民时期美国中西部北部地区树木生物量、茎干与断面积的统计估算》（https://www.biorxiv.org/content/10.1101/856526v1）。本研究工作受美国国家科学基金会资助，项目编号分别为DEB-1241874、1241868、1241870、1241851、1241891、1241846、1241856、1241930。