NPP Grassland: Dickinson, USA, 1970, R1

This data set contains three ASCII files (.txt format). Two files contain above- and below-ground biomass and productivity data for a northern mixed prairie grassland, one file for an ungrazed treatment and the other for a heavily grazed treatment. The study site (46.90 N, -102.82 W, Elevation 784 m) is located in the northern Great Plains, near the city of Dickinson, about 160-km west of Bismarck, North Dakota. The third file contains climate data for the period 1891-1994 obtained from a weather station near Dickinson (46.88 N, -102.80 W, Elevation 750 m).

Dynamics of above-ground living and dead plant biomass were monitored by the harvest technique at roughly 2-week intervals during the growing season of 1970. Total below-ground biomass was sampled at the same intervals by manual coring within the harvested plots to a depth sufficient to include at least 90% of the root mass. Data were collected as part of a coordinated study over 1-3 years at ten grassland sites of the central and western United States, under the US Grassland Biome Project of the International Biological Program (IBP).

Above-ground net primary productivity (ANPP) was estimated conservatively by summing peak biomass of individual species. These values were 351 g/m2/year for ungrazed and 302 g/m2/year for grazed grassland plots. Below-ground net primary productivity (BNPP) was estimated as the sum of positive increments in total root biomass (including root crowns); 932 g/m2/year for ungrazed and 958 g/m2/year for grazed grassland plots. Revision Notes: Only the documentation for this data set has been modified. The files have been checked for accuracy and are identical to those originally published in 1998.

本数据集包含三个 ASCII 文件（.txt 格式）。其中两个文件分别记录了北方混合草原地上生物量和生产力数据，一个针对未放牧处理，另一个针对重度放牧处理。研究地点（北纬 46.90，西经 -102.82，海拔 784 米）位于北美大平原北部，靠近北达科他州的迪金森市，位于比斯马克市西侧约 160 公里处。第三个文件包含了 1891-1994 年间从迪金森附近（北纬 46.88，西经 -102.80，海拔 750 米）气象站获取的气候数据。

通过收获技术，在 1970 年生长季节中每隔大约两周对地上存活和死亡的植物生物量进行监测。通过在收获区手动钻取样芯，以包含至少 90% 的根质量为深度，在相同的时间间隔内对地下生物量进行采样。这些数据是在美国国际生物计划（IBP）下的美国草原生物群落项目框架内，对中西部十个草原地点进行为期 1-3 年的协调研究的一部分。

通过累加单个物种的峰值生物量，保守地估计了地上净初级生产力（ANPP）。未放牧和放牧草原地块的这些值分别为 351 克/平方米/年和 302 克/平方米/年。地下净初级生产力（BNPP）估计为总根生物量（包括根冠）的正增量之和；未放牧和放牧草原地块的这些值分别为 932 克/平方米/年和 958 克/平方米/年。修订说明：仅对该数据集的文档进行了修改。文件已检查以确保准确性，与 1998 年最初发表的内容完全一致。