This data set contains measurements of ant abundance (number of individuals observed at the baits) and ant occurrence (binary data) measured in the Main Experiment plots of a large grassland biodiversity experiment (the Jena Experiment; see further details below). Ants were sampled in 80 plots of the Main Experiment using baited traps in July 2006. In each plot two petri dishes were set on the ground, one received ~10g of Tuna the other ~10g of sugar (Sucrose). After 30min the occurrence (presence = 1 / absence = 0) and abundance (number) of ants at the two baits was recorded. Given is, per plot, the sum of ants attracted to the two different baits. 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 in the plots to create a gradient of plant species richness (1, 2, 4, 8, 16 and 60 species) and functional richness (1, 2, 3, or 4 functional groups). Plots were maintained by bi-annual weeding and mowing.
The main experiment on the field site of the Jena Experiment comprises a split-plot design in which additional treatments (e.g. no weeding allowing for invasion of other species, or application of fertilizer) have been applied to subplots along the outer margin of the plots (see Treatment description in the section “further details”). While in this dataset only data from the core area (mown and weeding of all none-sown species twice a year, no additional treatments) is reported, all potential treatments are listed as the first parameters in the data file to guarantee compatibility with other datasets that include different treatments.This dataset is part of a collection of measurements on invertebrate abundances and diversities in the Jena Experiment. Data for other taxonomic groups, from other experiments (e.g. Main Experiment, Dominance Experiment; see details above), other years, or other methods quantifying related data might be available (doi:10.1594/PANGAEA.865172).
