Jornada Experimental Range (USDA-ARS) monthly stocking data and pasture shape files from 1915 to 1952

This data package contains two types of data for the Jornada
Experimental Range (JER) from 1915 to 1952: 1) shape files
containing polygons and attribute tables that represent the pasture
configurations on the Jornada Experimental Range and 2) monthly
stocking data from these pastures. The livestock represented in the
stocking data comprise cattle, horse, sheep, and goats. Grazing
goats were infrequent and are grouped with sheep in the source data.
As such for this data set, they are included in the sheep category.
Stocking data are expressed in animal unit months (AUM), which is
based on metabolic weight. This data package provides finer resolution AUM data than
knb-lter-jrn.210412001, which presents the annual stocking data for
the entire JER from 1916 to 2001. The stocking data in this package
begins in June of 1915 and continues through December of 1952, the
last year for which the researchers on this project have verified
and digitized historical pasture configurations on the JER. https://portal.edirepository.org/nis/mapbrowse?scope=knb-lter-jrn&identifier=210412001

本数据包收录了1915年至1952年约霍马实验牧场（Jornada Experimental Range, JER）的两类数据：
1) 包含多边形要素与属性表的形状文件（shape files），用于表征约霍马实验牧场的牧场区划布局；
2) 对应各该牧场的月度载畜数据。

该载畜数据涵盖的畜禽包括牛、马、绵羊与山羊。源数据中因山羊放牧频次极低，故将其与绵羊合并归类，本数据集沿用该分类规则，将山羊归入绵羊类别。

载畜量以动物单位月（animal unit months, AUM）为计量单位，其计算基于代谢体重。

本数据包提供的动物单位月数据分辨率高于数据集knb-lter-jrn.210412001——该数据集收录了1916年至2001年约霍马实验牧场全域的年度载畜数据。

本数据包的载畜数据起始于1915年6月，截至1952年12月，这也是本项目研究人员完成验证与数字化的约霍马实验牧场历史牧场区划布局的最后一年。相关链接：https://portal.edirepository.org/nis/mapbrowse?scope=knb-lter-jrn&identifier=210412001