In a 12-year old biodiversity experiment (Jena Experiment) comprising 80 grassland communities with six levels of plant species richness (1, 2, 4, 8, 16 and 60 species) and four levels of functional groups richness (1, 2, 3 and 4 functional groups), we studied populations of 38 dicotyledonous forb species (N = 1,683 plant individuals).

The sampled individuals represented three plant functional groups (legumes, small herbs, tall herbs) and two different growth forms (species with long-lived primary roots, or clonal species with rhizomes/stolons). We assessed the age of plant individuals by means of growth ring analysis and related the age of plant populations to their temporal stability in terms of peak biomass production.

Variable description:

ID: identification number for sampled individuals
Plot: plot of the biodiversity experiment
Block: block of the biodiversity experiment
SR: sown species richness
Species: species name
FG.ID: functional group identity of sampled individual (le = legume, sh = small herb, th = tall herb)
Growth: growth form of species tr = taproot, cl = clonal (stolons or rhizomes)
Dis: discernibility of growth rings 1 = perfect discernibility, 2 = good discernibility, 3 = low discernibility, 4 = growth rings not visible
Age: age of sampled individual based on growth ring counts in years
Used: samples included in analysis 0 = no, 1 = yes
Missing values are identified by NA