Standing belowground plant biomass from the Jena Experiment (Main Experiment, year 2011)

This data set contains measurements of standing belowground plant biomass. Data presented here is from the Main Experiment plots of a large grassland biodiversity experiment (the Jena Experiment; see further details below). In the Main experiment, 82 grassland plots of 20 x 20 m were established from a pool of 60 species belonging to four functional groups (grasses, legumes, tall and small herbs). In May 2002, varying numbers of plant species from this species pool were sown into the plots to create a gradient of plant species richness (1, 2, 4, 8, 16 and 60 species) and functional richness (1, 2, 3, 4 functional groups). Plots were maintained in general by bi-annual weeding and mowing. Since 2010, plots were weeded three times per year. Plot size was reduced to 5 x 6 m since 2010.
In 2011, standing root biomass was sampled in June. Three (two in few cases because of stones) soil cores with a 3.5 cm diameter per plot were taken to 40 cm depth and pooled plot-wise. The cores were immediately stored cool until further handling. The bulk material of the pooled cores was weighed and cut with scissors to < 1 cm pieces. For root washing, the bulk sample was soaked in water and then repeatedly rinsed with tap water over a 0.5 mm sieve. Remaining soil particles were removed by hand. Roots were dried at 60 - 70 °C and weighed subsequently. In 2011, soil cores were separated in depth increments of 0-5, 5-10, 10-20, 20-30 and 30 - 40 cm depth and the corresponding layers were pooled plot-wise. Roots were not seperated in coarse (diameter > 2 mm) and fine roots and only total root biomass is shown in this dataset.