Aboveground species-specific plant biomass from the Jena Trait Based Experiment (year 2012)@en

This data set contains aboveground plant biomass (Sown plant species, Weed plant biomass, the biomass of dead plant material, and the biomass of unidentified plant material) per plots collected in 2012 from a grassland trait diversity experiment (the Jena Trait Based Experiment). The experiment consists of 20 plant species that were assigned to one of three species pools: 1. Species that vary along a gradient of spatial leaf and root trait similarity, 2. Species that vary along a gradient of phenological trait similarity and 3. Species that vary along a gradient of both spatial and phenological similarity (see Ebeling et al. 2014). The experiment consists of 138 grassland plots 3 x 3 m in size that was established within the Jena Experiment, Germany, in 2011. Plots vary in plant species richness (1, 2, 4, or 8 species) and functional diversity (1, 2, 3, 4 functional diversity levels, where 1 indicates species are most similar and 4 being most dissimilar in functional traits). Plots were maintained by manual weeding in March, July and September. Biomass was harvested twice in 2012 (during peak standing biomass in late May and in late August) on all experimental plots. Plots were mown to the same height directly following biomass harvest. Plant biomass was harvested by clipping the vegetation at 3 cm above ground in two 0.2 x 0.5 m quadrats 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. the central 10 x 15 m). The positions of the rectangles within plots were identical for all plots. The harvested biomass was sorted into categories: individual species of the sown plant species, 'Weed' plant species (species not sown in a plot), detached 'Dead' plant material, and remaining plant material that could not be assigned to any category ('Rest'). All biomass was dried to constant weight (70°C, >= 48 h) and weighed. The data from individual quadrats were averaged.

本数据集包含2012年取自耶拿功能性状驱动草地实验（Jena Trait Based Experiment）的样地地上植物生物量数据，具体涵盖播种植物物种生物量、杂草植物生物量、枯落植物材料生物量及未鉴定植物材料生物量。
该实验共选用20种植物，将其划分为3个物种库：1. 沿叶片与根系空间性状相似性梯度变化的物种；2. 沿物候性状相似性梯度变化的物种；3. 同时沿空间与物候性状相似性梯度变化的物种（详见Ebeling等2014年研究）。
本实验于2011年在德国耶拿实验场内建立，共设置138块3×3米的草地样地。样地的植物物种丰富度（1、2、4或8种）与功能多样性（1、2、3、4个功能多样性水平，其中1代表物种功能性状相似度最高，4代表相似度最低）存在差异。
样地分别于每年3月、7月和9月通过人工除草进行维护。2012年，所有实验样地均在两次地上生物量峰值期（5月末与8月末）开展生物量收割作业，收割后所有样地均被统一修剪至相同高度。
每块样地内选取两个0.2×0.5米的样方，在距地面3厘米处剪除植被以采集植物生物量。每次收割前，通过在样地核心区域（即中央10×15米范围）内随机选取坐标确定样方位置，且所有样地的样方位置均保持一致。
收割得到的生物量被分为以下类别：播种的目标植物物种个体、“杂草”物种（即样地中未被播种的植物）、脱落的“枯落”植物材料，以及无法归类的剩余植物材料（"Rest"）。所有生物样本均置于70℃环境下烘干至恒重（时长≥48小时）后称重，最后对单个样方的生物量数据取平均值。