Aboveground plant biomass from the Jena Experiment (Monocultures, year 2002)

This data set contains aboveground plant biomass in 2002 (Sown plant community; measured in biomass as dry weight) of the monoculture plots of a large grassland biodiversity experiment (the Jena Experiment). In the monoculture plots the biomass of the sown plant community contains only a single species per plot and this species is a different one for each plot. Which species has been sown in which plot is stated in the plot information table for monocultures (see further details below). The monoculture plots of 3.5 x 3.5 m were established for all of the 60 plant species of the Jena Experiment species pool with two replicates per species. These 60 species comprising the species pool of the Jena Experiment belong to four functional groups (grasses, legumes, tall and small herbs). Plots were sown in May 2002 and are since maintained by bi-annual weeding and mowing.
Aboveground plant biomass was harvested twice in 2002 just prior to mowing (during peak standing biomass in early June and in late August) on all experimental plots of the monocultures. This was done by clipping the vegetation at 3 cm above ground in 2 rectangles of 0.2 x 0.5 m per plot. The location of these rectangles was assigned prior to each harvest by random selection of coordinates within the core area of the plots (i.e. excluding an outer edge of 0.5 m). The positions of the rectangles within plots were identical for all plots. From the harvested biomass only the separated biomass of the sown plant species was kept. All biomass was dried to constant weight (70°C, >= 48 h) and weighed. The data for individual subsamples (i.e. rectangles) and the mean over samples for all biomass measures are given.

本数据集包含2002年某大型草原生物多样性实验——耶拿实验（Jena Experiment）的单播样地地上植物生物量数据（播撒植物群落，以干重生物量计量）。单播样地内，每个样地的播撒植物群落仅包含单一物种，且各单播样地的播撒物种互不相同。各单播样地对应的播撒物种信息，详见单播样地信息表（详见下文补充说明）。该实验针对耶拿实验植物物种库的全部60个植物物种，设置了规格为3.5×3.5米的单播样地，每个物种设置2个重复样地。构成耶拿实验物种库的这60个物种，隶属于4个功能群：禾本科草本、豆科草本、高大草本与矮小草本。所有样地于2002年5月完成播撒，并通过每年两次的除草与刈割进行管护。
2002年，所有单播实验样地均于刈割前的两个地上生物量峰值期（6月初与8月底）进行了两次地上生物量取样。取样方式为：在每个样地内的两个0.2×0.5米矩形区域中，于地面3厘米高度处剪除植被。每次取样前，均在样地核心区域（即排除0.5米外围边缘后的区域）内随机选取坐标以确定矩形取样区的位置，且所有样地内的矩形取样区位置保持一致。仅留存取样得到的生物量中播撒植物物种的部分。所有生物量样品均经70℃烘干≥48小时至恒重后称重。数据集同时提供了单个子样品（即矩形取样区）的测定数据，以及所有生物量测定指标的样地平均值。