Age and stem anatomical traits of Galium mollugo (collected between 2017-2019 in three regions of Germany)

Life span of plants is a key demographic trait important for the life history of plant species, the persistence and stability of plant populations and plant species` responses to environmental changes. However, information on the longevity of plant individuals (or ramets) and specifically its variation dependent on environmental conditions such as land use or regional differences in climatic conditions is not available for a large number of grassland species. Stem anatomical traits related to functions such as transport, storage and mechanical support are largely ignored in ecological studies of herbaceous species and therefore it is not known how sensitively these traits respond to variation in environmental conditions.<br>The data contain the age and stem anatomical traits of Galium mollugo, which was sampled with 20 individuals in 64 populations (in four cases with less individuals) located on grassland experimental plots (EP) in the three German regions (Schwäbische Alb, Hainich-Dün, Schorfheide-Chorin) chosen to represent different land-use intensities in each region to get an estimate of age distribution within populations. The age was determined by counting growth rings at the oldest part of plant samples (root crown, or distal part of rhizoms) in thin cross sections made with a microtome; the width of the stem anatomical tissues (diameter of the pith, and width of phellem, cortex, phloem, xylem and individual growth rings) was also measured at the cross sections. The data collection was part of the project ForbAge within the framework of the DFG-funded joint project Biodiversity Exploratories (https://www.biodiversity-exploratories.de).