ALBERT

Description: This supplement contains results of fossil diatom counting and results and methodology of XRF analysis of a sediment core (RK12) from Lake Kushu (Rebun Island) as well as modern water chemistry data and modern diatom counts of samples from Lake Kushu and Hime-numa Pond (Rishiri Island) in northern Hokkaido, Japan.

Description: This collection contains measurements of physical and chemical soil properties 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 in general by bi-annual weeding and mowing. Since 2010, plot size was reduced to 5 x 6 m and plots were weeded three times per year. The following series of datasets are contained in this collection: 1. Physical soil properties - Soil texture: Proportion of sand, silt and clay in the fine soil was measured in April 2002 before plot establishment at 27 locations distributed throughout the experimental site. Undisturbed soil cores were taken to 100 cm depth and separated in depth increments with a resolution of 10 to 20 cm. Grain size fractions according to DIN 19683-2 were then determined by a combined sieve and hydrometer analysis. Values for each plot were interpolated by ordinary kriging. - Bulk density: Bulk density was sampled down to 100 cm depth in 2002 and 30 cm depth in 2004, 2006 and 2008. Several undisturbed soil cores were taken per plot and separated in depth increments before the bulk material was sieved, dried and weighed. - Soil hydraulic properties: Field capacity and permanent wilting point at 10, 20 and 30 cm depth were derived from soil texture data of 2002 and bulk density 2006 by using pedotransfer functions. Applied was equation four and five of Zacharias and Wessolek (2007) to derive parameters of the water retention curve. Water contents at field capacity and permanent wilting point were obtained using the van Genuchte Eq (e.g. eq 1 in Zacharias and Wessolek), and calculating water contents at - 330 cm matric potential (field capacity, 1/3 of atmospheric pressure) and at -15000 cm. -Soil porosity: the fraction of total volume occupied by pores or voids measured at matric potential 0, already published on https://doi.pangaea.de/10.1594/PANGAEA.865254. 2. Chemical soil properties - Lime content: Percentage of CaCO3 in the soil was measured in April 2002 before plot establishment at 27 locations distributed throughout the experimental site. Undisturbed soil cores were taken to 100 cm depth and separated in depth increments with a resolution of 10 to 20 cm. The bulk material was sieved and CaCO3 content of the fine soil was determined as volumetric determination according to DIN 19684-5. - Soil organic matter: Percentage of soil organic matter was measured in April 2002 before plot establishment at 27 locations distributed throughout the experimental site. Undisturbed soil cores were taken to 100 cm depth and separated in depth increments with a resolution of 10 to 20 cm. The bulk material was sieved and organic content of the fine soil was determined using a loss-on-ignition method. - Soil pH value: soil pH value was determined 2002 and 2010 in water and 2002 also in calcium chloride. Five soil samples were taken per plot and bulk material was diluted in water and calcium chloride. PH values were then measured with an electrode.

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.