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.

The monoculture data belongs to the Jena Experiment data set representing all species sown in the main experiment on the field site of the Jena Experiment. There are two types of missing values contained in the dataset. Empty cells represent missing values that result from the design of the experiment when the respective value does not occur and could thus not be measured. For example, the columns of half of the cells are left blank since 2008 when on the plot replicates was given up. Missing values that resulted from methodological problems, sampling errors, or lost samples/data are marked with “-9999”.This datasets is part of a collection of time series of biomass measurements in the Jena Experiment since 2002 (doi:10.1594/PANGAEA.866358). Similar data from other experiments (e.g. Main Experiment, Dominance Experiment; see details above), other years, or other methods quantifying related data might be available in this collection.