Description: This data collection contains species-specific aboveground plant biomass that was collected from the Trait Based Experiment in 2012. (Sown plant species, Weed plant biomass, the biomass of dead plant material, and the biomass of unidentified plant material) per plots collected in 2012 from a grassland trait diversity experiment (the Jena Trait Based Experiment). The data collection also contains the traits of the species measured in their monoculture. The experiment consists of 20 plant species that were assigned to one of three species pools: 1. Species that vary along a gradient of spatial leaf and root trait similarity, 2. Species that vary along a gradient of phenological trait similarity and 3. Species that vary along a gradient of both spatial and phenological similarity (see Ebeling et al. 2014). The experiment consists of 138 grassland plots 3 x 3 m in size that was established within the Jena Experiment, Germany, in 2011. Plots vary in plant species richness (1, 2, 4, or 8 species) and functional diversity (1, 2, 3, 4 functional diversity levels, where 1 indicates species are most similar and 4 being most dissimilar in functional traits). Plots were maintained by manual weeding in March, July and September. Biomass was harvested twice in 2012 (during peak standing biomass in late May and in late August) on all experimental plots. Plots were mown to the same height directly following biomass harvest. Plant biomass was harvested by clipping the vegetation at 3 cm above ground in two 0.2 x 0.5 m quadrats per plot. The harvested biomass was sorted into categories: individual species of the sown plant species, 'Weed' plant species (species not sown in a plot), detached 'Dead' plant material, and remaining plant material that could not be assigned to any category ('Rest'). All biomass was dried to constant weight (70°C, 〉= 48 h) and weighed. The data from individual quadrats were averaged. The traits measured are: Flowering initiation, Flowering cessation, specific leaf area (SLA), leaf dry matter content (LDMC), leaf area, maximum canopy height, specific root length (SRL), mean rooting depth (MRD), root mass density (RMD) and root length density (RLD). Flowering initiation and cessation were measured respectively as the week in which flowering was first observed and flowering senesce had completed throughout the plot. Leaf area, leaf fresh mass were measured on approximately five fully expanded leaves from different individuals. These leaves were dried at 65°C for over 48 hours and massed to calculate the specific leaf area (SLA, area per dry mass), and the leaf dry matter content (LDMC, dry mass per fresh mass). Maximum canopy height was measured during peak biomass in May by taking the average of five measurements along a transect. Root traits were measured by taking soil cores, 4 cm in diameter and 40 cm deep and sectioned by depth: 0-5, 5-10, 10-20, 20-30 and 30-40 cm. Roots were washed and roots 〈 2 mm in diameter were stored in 70 % ethanol. Root length was determined by scanning stained roots with neutral red and scanning roots using WinRhizo software. Root traits were only measured in species pool 1 and 2. Roots were then dried at 65°C for over 48 hours and massed to determine the specific root length (SRL, root length per mass), mean rooting depth (MRD, the average depth weighed by root mass per depth), root mass density (RMD, the average root mass per cubic cm volume) and root length density (RLD, root mass per root length).

Description: This data set contains plant species traits: Flowering initiation, Flowering cessation, specific leaf area (SLA), leaf dry matter content (LDMC), leaf area, maximum canopy height, specific root length (SRL), mean rooting depth (MRD), root mass density (RMD) and root length density (RLD). The traits were measured during the summer of 2012 on the plants grown in monoculture within a grassland trait diversity experiment (the Jena Trait Based Experiment). The experiment consists of 20 plant species that were assigned to one of three species pools: 1. Species that vary along a gradient of spatial leaf and root trait similarity, 2. Species that vary along a gradient of phenological trait similarity and 3. Species that vary along a gradient of both spatial and phenological similarity (see Ebeling et al. 2014). The plots were 3 x 3 m in size and established within the Jena Experiment, Germany, in 2011. Plots were maintained by manual weeding in March, July and September. Traits were measured during the summer of 2012. Flowering initiation and cessation were measured respectively as the week in which flowering was first observed and flowering senesce had completed throughout the plot. Leaf area, leaf fresh mass were measured on approximately five fully expanded leaves from different individuals. These leaves were dried at 65 C for over 48 hours and massed to calculate the specific leaf area (SLA, area per dry mass), and the leaf dry matter content (LDMC, dry mass per fresh mass). Maximum canopy height was measured during peak biomass in May by taking the average of five measurements along a transect. Root traits were measured by taking soil cores, 4 cm in diameter and 40 cm deep and sectioned by depth: 0-5, 5-10, 10-20, 20-30 and 30-40 cm. Roots were washed and roots 〈 2 mm in diameter were stored in 70 % ethanol. Root length was determined by scanning stained roots with neutral red and scanning roots using WinRhizo software. Root traits were only measured in species pool 1 and 2. Roots were then dried at 65 C for over 48 hours and massed to determine the specific root length (SRL, root length per mass), mean rooting depth (MRD, the average depth weighed by root mass per depth), root mass density (RMD, the average root mass per cubic cm volume) and root length density (RLD, root mass per root length).

Description: This collection contains measurements of element concentrations in plants on 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 by bi-annual weeding and mowing. The following series of datasets are contained in this collection: 1. Carbon and nitrogen concentration in plants: C and N concentration in aboveground plant biomass was measured twice a year (once in 2002 and 2009) from 2002 to 2012. Plants were clipped at 3 cm above ground level in three or four rectangles of 20 x 50 cm size per plot. Target species were pooled per plot and harvest, dried at 70 °C for at least 48 h and cut up with an analysis mill (Kinematica, Littau, Schweiz). The cut material was milled in a ball-mill and carbon and nitrogen concentration was determined with an elemental analyzer. In 2010, phosphorous and potassium concentration was measured additionally. For this purpose, a subsample of the dried and cut material was milled and digested with HNO3 at 200 °C and at about 600-700 MPa using the microwave-assisted high pressure digestion unit (Ethos, Mikrowellen-Laborsysteme (MLS), Leutkirch, Germany). Phosphorus concentrations were determined in a Continuous Flow Analyzer, AA3-system (Bran and Lübbe, Hamburg-Norderstedt, Germany). For K measurement, atom absorption spectroscopy (AAS, Zeenit 700P, Analytik Jena, Jena, Germany) was used. 2. Carbon and nitrogen concentration in plants of the drought experiment: C and N concentration in aboveground plant biomass was measured once a year in 2008 and 2009 on the subplots of the drought experiment. Plants were harvested in rectangles of 20 x 50 cm size. Target species were dried at 70 °C for 48 h, grounded to powder and analyzed with an elemental analyzer. 3. Element analysis of phosphorous (P), calcium (Ca), potassium (K), sodium (Na) and magnesium (Mg) in plants: P, Ca, K, Na and Mg concentrations in aboveground plant biomass were measured twice a year (once in 2004) from 2003 to 2007. Plants were clipped at 3 cm above ground level in three or four rectangles of 20 x 50 cm size per plot. Target species were pooled per plot and harvest, dried at 70 °C for at least 48 h, shredded and milled. Each sample was digested with HNO3 at 200 °C and at about 600-700 MPa using the microwave-assisted high pressure digestion unit (Mars 5 Express, CEM, Lintfort, Germany). Phosphorus concentrations were determined in a Continuous Flow Analyzer, AA3-system (Bran and Lübbe, Hamburg-Norderstedt, Germany). For Ca, K, Na and Mg measurement, atom absorption spectroscopy (AAS, AS240FS Fast Sequential AAS, Varian, Palo Alto, USA) was used.

Description: This data set contains aboveground plant biomass (Sown plant species, Weed plant biomass, the biomass of dead plant material, and the biomass of unidentified plant material) per plots collected in 2012 from a grassland trait diversity experiment (the Jena Trait Based Experiment). The experiment consists of 20 plant species that were assigned to one of three species pools: 1. Species that vary along a gradient of spatial leaf and root trait similarity, 2. Species that vary along a gradient of phenological trait similarity and 3. Species that vary along a gradient of both spatial and phenological similarity (see Ebeling et al. 2014). The experiment consists of 138 grassland plots 3 x 3 m in size that was established within the Jena Experiment, Germany, in 2011. Plots vary in plant species richness (1, 2, 4, or 8 species) and functional diversity (1, 2, 3, 4 functional diversity levels, where 1 indicates species are most similar and 4 being most dissimilar in functional traits). Plots were maintained by manual weeding in March, July and September. Biomass was harvested twice in 2012 (during peak standing biomass in late May and in late August) on all experimental plots. Plots were mown to the same height directly following biomass harvest. Plant biomass was harvested by clipping the vegetation at 3 cm above ground in two 0.2 x 0.5 m quadrats 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. the central 10 x 15 m). The positions of the rectangles within plots were identical for all plots. The harvested biomass was sorted into categories: individual species of the sown plant species, 'Weed' plant species (species not sown in a plot), detached 'Dead' plant material, and remaining plant material that could not be assigned to any category ('Rest'). All biomass was dried to constant weight (70°C, 〉= 48 h) and weighed. The data from individual quadrats were averaged.

Description: Data presented here were collected between November 2014 to April 2017 within the BEFmate project (Biodiversity - Ecosystem Functioning across marine and terrestrial ecosystems; https://www.icbm.de/verbundprojekte/befmate/) of the Universities of Oldenburg and Göttingen and the Nationalparkverwaltung Niedersächsisches Wattenmeer. Experimental islands and saltmarsh control plots were created in the back barrier tidal flat and in the saltmarsh zone of Spiekeroog island. Data were measured with a local installed weatherstation near the experimental setup. The weatherstation system used is a ClimaSensor US (Adolf Thies GmbH & Co. KG, D-Göttingen). The sensors were pre-calibrated by the manufacturer. Data were recorded with the Meteo-Online (V4.5.0.20253) software and processed using MATLAB (R2012b). Data were visually checked and outliers removed. The position was derived from the intern GPS-system. Date and Time is given in UTC.