Benthic foraminifera in surface sediments of the Arabian Sea

Assemblages of living deep-sea benthic foraminifera, their densities, vertical distribution pattern, and diversity, were investigated in the intermonsoon period after the northeast monsoon in the Arabian Sea in spring 1997. Foraminiferal numbers show a distinct gradient from north to south, with a maximum of 623 foraminifera in 50 cm**3 at the northern site. High percentages of small foraminifera were found in the western and northern part of the Arabian Sea. Most stations show a typical vertical distribution with a maximum in the first centimeter and decreasing numbers with increasing sediment depths. But at the central station, high densities can be found even in deeper sediment layers. Diversity is very high at the northern and western sites, but reduced at the central and southern stations. Data and faunal assemblages were compared with studies carried out in 1995. A principal component analysis of intermonsoon assemblages shows that the living benthic foraminifera can be characterized by five principal component communities. Dominant communities influencing each site differ strongly between the two years. In spring 1997, stations in the north, west and central Arabian Sea were dominated by opportunistic species, indicating the influence of fresh sedimentation pulses or enhanced organic carbon fluxes after the northeast monsoon.

Benthic foraminifera in surface sediments of the Gulf of Lions

Surface sediment was sampled at two bathyal sites in the southwestern Gulf of Lions in the western Mediterranean Sea in February and August 1997 to study the distribution and microhabitat of living (Rose Bengal stained) deep sea benthic foraminifera. Both standing stock and diversity of the faunas, and the microhabitat of distinct species mirror the trophic situation and the depth of the oxidised layer at the different sites. Our results suggest that the faunas do not comprise highly opportunistic species and are adapted to rather stable environments. In the axial channel of the Lacaze-Duthiers Canyon, organic matter fluxes are enhanced due to advective transport of organic matter resulting in elevated oxygen consumption rates in the surface sediment and a rather thin oxidised layer. The corresponding benthic foraminiferal fauna is characterised by rather high standing stock and diversity, and a well-developed deep infauna. In addition to freshly deposited phytodetritus, more degraded organic matter seems to be an important food source. In contrast, at the open slope, organic matter fluxes and oxygen consumption rates in the surface sediment are lower and the oxidised layer is much thicker than inside the canyon. The corresponding benthic foraminiferal fauna comprises mainly epifaunal and shallow-infaunal species with much lower standing stocks and clear differences between February and August. In August standing stocks are higher and the average living depths of most species shift towards the sediment surface. These differences can be attributed to patchiness or represent a seasonal trophic signal.

Aboveground community and species-specific plant biomass from the Jena Experiment (Main Experiment, year 2003)

This data set contains aboveground community biomass (Sown plant community, Weed plant community, Dead plant material, and Unidentified plant material; all measured in biomass as dry weight) and species-specific biomass from the sown species of 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. Aboveground community biomass was harvested twice in 2003 just prior to mowing (during peak standing biomass in late May and in late August) on all experimental plots of the main experiment. This was done by clipping the vegetation at 3 cm above ground in four rectangles of 0.2 x 0.5 m per large 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 for the sown plant species, weed plant species (species not sown at the particular plot), detached dead plant material (i.e., dead plant material in the data file), and remaining plant material that could not be assigned to any category (i.e., unidentified plant material in the data file). All biomass was dried to constant weight (70°C, >= 48 h) and weighed. Sown plant community biomass was calculated as the sum of the biomass of the individual sown species. The data for individual samples and the mean over samples for the biomass measures on the community level are given. Overall, analyses of the community biomass data have identified species richness as well as functional group composition as important drivers of a positive biodiversity-productivity relationship.

Aboveground community and species-specific plant biomass from the Jena Experiment (Dominance Experiment, year 2006)

This data set contains aboveground community plant biomass (Sown plant community, Weed plant community, Dead plant material, and Unidentified plant material; all measured in biomass as dry weight) and species-specific biomass from the sown species of the dominance experiment plots of a large grassland biodiversity experiment (the Jena Experiment; see further details below). In the dominance experiment, 206 grassland plots of 3.5 x 3.5 m were established from a pool of 9 plant species that can be dominant in semi-natural grassland communities of the study region. 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, 3, 4, 6, and 9 species). Plots were maintained by bi-annual weeding and mowing. Aboveground community biomass was harvested twice in May and August 2006 on all experimental plots of the dominance experiment. This was done by clipping the vegetation at 3 cm above ground in two rectangles of 0.2 x 0.5 m per experimental plot. The location of these rectangles was assigned by random selection of coordinates within the central area of the plots (excluding an outer edge of 50cm). The positions of the rectangles within plots were identical for all plots. The harvested biomass was sorted into categories: individual species for the sown plant species, weed plant species (species not sown at the particular plot), detached dead plant material, and remaining plant material that could not be assigned to any category. All biomass was dried to constant weight (70°C, >= 48 h) and weighed. Sown plant community biomass was calculated as the sum of the biomass of the individual sown species. The mean of both samples per plot and the individual measurements are provided in the data file. Overall, analyses of the community biomass data have identified species richness and the presence of particular species as an important driver of a positive biodiversity-productivity relationship.

Species-specific plant height along the plant diversity gradient in the Jena Experiment (Main Experiment, year 2002)

This data set contains measurements of species-specific plant height: vegetative height (non-flowering indviduals) and regenerative height (flowering individuals) measured for all sown species separetly in 2002. Data was recorded in 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. In 2002, plant height was recorded two times: in late July (vegetative height) and just before biomass harvest during peak standing biomass in late August (vegetative and regenerative height). For each plot and each sown species in the species pool, 3 plant individuals (if present) from the central area of the plots were randomly selected and used to measure vegetative height (non-flowering indviduals) and regenerative height (flowering individuals) as stretched height. Provided are the means over the three measuremnts per plant species per plot.

Aboveground community and species-specific plant biomass from the Jena Experiment (Dominance Experiment, year 2003)

This data set contains aboveground community plant biomass (Sown plant community, Weed plant community, and Dead plant material; all measured in biomass as dry weight) and species-specific biomass from the sown species of the dominance experiment plots of a large grassland biodiversity experiment (the Jena Experiment; see further details below). In the dominance experiment, 206 grassland plots of 3.5 x 3.5 m were established from a pool of 9 plant species that can be dominant in semi-natural grassland communities of the study region. 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, 3, 4, 6, and 9 species). Plots were maintained by bi-annual weeding and mowing. Aboveground community biomass was harvested twice in May and August 2003 on all experimental plots of the dominance experiment. This was done by clipping the vegetation at 3 cm above ground in two rectangles of 0.2 x 0.5 m per experimental plot. The location of these rectangles was assigned by random selection of coordinates within the central area of the plots (excluding an outer edge of 50cm). The positions of the rectangles within plots were identical for all plots. The harvested biomass was sorted into categories: individual species for the sown plant species, weed plant species (species not sown at the particular plot), detached dead plant material, and remaining plant material that could not be assigned to any category. All biomass was dried to constant weight (70°C, >= 48 h) and weighed. Sown plant community biomass was calculated as the sum of the biomass of the individual sown species. The mean of both samples per plot and the individual measurements are provided in the data file. Overall, analyses of the community biomass data have identified species richness and the presence of particular species as an important driver of a positive biodiversity-productivity relationship.

Aboveground community and species-specific plant biomass from the Jena Experiment (Main Experiment, year 2005)

This data set contains aboveground community biomass (Sown plant community, Weed plant community, Dead plant material, and Unidentified plant material; all measured in biomass as dry weight) and species-specific biomass from the sown species of 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. Aboveground community biomass was harvested twice in 2005 just prior to mowing (during peak standing biomass in late May and in late August) on all experimental plots of the main experiment. This was done by clipping the vegetation at 3 cm above ground in three (in May 2005) and four (August 2005) rectangles of 0.2 x 0.5 m per large 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 for the sown plant species, weed plant species (species not sown at the particular plot), detached dead plant material (i.e., dead plant material in the data file), and remaining plant material that could not be assigned to any category (i.e., unidentified plant material in the data file). All biomass was dried to constant weight (70°C, >= 48 h) and weighed. Sown plant community biomass was calculated as the sum of the biomass of the individual sown species. The data for individual samples and the mean over samples for the biomass measures on the community level are given. Overall, analyses of the community biomass data have identified species richness as well as functional group composition as important drivers of a positive biodiversity-productivity relationship.

Benthic foraminifera of the Labrador Sea and Buffin Bay

Trigger weight (TWC) and piston (PC) cores obtained from surveys of the three sites drilled during Ocean Drilling Program (ODP) Leg 105 were studied in detail for benthic foraminiferal assemblages, total carbonate (all sites), planktonic foraminiferal abundances (Sites 645 and 647), and stable isotopes (Sites 646 and 647). These high-resolution data provide the link between modern environmental conditions represented by the sediment in the TWC and the uppermost cores of the ODP holes. This link provides essential control data for interpretating late Pleistocene paleoceanographic records from these core holes. At Site 645 in Baffin Bay, local correlation is difficult because the area is dominated by ice-rafted deposits and by debris flows and/or turbidite sedimentation. At the two Labrador Sea sites (646 and 647), the survey cores and uppermost ODP cores can be correlated. High-resolution data from the site survey cores also provide biostratigraphic data that refine the interpretations compiled from core-catcher samples at each ODP site.

Aboveground community and species-specific plant biomass from the Jena Experiment (Main Experiment, year 2002)

This data set contains aboveground community biomass (Sown plant community, measured in biomass as dry weight) and species-specific biomass from the sown species of 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. Aboveground community biomass was harvested in September 2002 just prior to mowing (during peak standing biomass) on all experimental plots of the main experiment. This was done by clipping the vegetation at 3 cm above ground in one rectangle of 0.2 x 0.5 m per large plot. The location of the rectangle was assigned prior to 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 rectangle within plots were identical for all plots. The harvested biomass was sorted into categories: in 2002 only individual species for the sown plant species were separated and processed. All biomass was dried to constant weight (70°C, >= 48 h) and weighed. Sown plant community biomass was calculated as the sum of the biomass of the individual sown species. Overall, analyses of the community biomass data have identified species richness as well as functional group composition as important drivers of a positive biodiversity-productivity relationship.

Aboveground community and species-specific plant biomass from the Jena Experiment (Main Experiment, time series since 2002)

This data set comprises a time series of aboveground community plant biomass (Sown plant community, Weed plant community, Dead plant material, and Unidentified plant material; all measured in biomass as dry weight) and species-specific biomass from the sown species of 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. Aboveground community biomass was harvested twice a year just prior to mowing (during peak standing biomass twice a year, generally in May and August; in 2002 only once in September) on all experimental plots of the main experiment. This was done by clipping the vegetation at 3 cm above ground in up to four rectangles of 0.2 x 0.5 m per large plot. The location of these rectangles was assigned by random selection of new coordinates every year 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 for the sown plant species, weed plant species (species not sown at the particular plot), detached dead plant material (i.e., dead plant material in the data file), and remaining plant material that could not be assigned to any category (i.e., unidentified plant material in the data file). All biomass was dried to constant weight (70°C, >= 48 h) and weighed. Sown plant community biomass was calculated as the sum of the biomass of the individual sown species. The data for individual samples and the mean over samples for the biomass measures on the community level are given. Overall, analyses of the community biomass data have identified species richness as well as functional group composition as important drivers of a positive biodiversity-productivity relationship.

Foraminiferal assemblages of the Mackenzie-Beaufort Sea Slope and Amundsen Gulf

Two cores, one from the Beaufort Sea Slope at 1000 m water depth (core 750) and one from the Amundsen Gulf at 426 m (core 124), were collected to help determine paleo-ice cover in the Holocene and late glacial of this area. Site 750 is particularly sensitive to changes in paleo-ice cover because it rests beneath the present ice margin of the permanent Arctic ice pack. Core 124 was sampled just in front of the former glacier that moved out into the Amundsen Gulf and started to recede about 13 ka B.P. Both cores have a strong occurrence of calcareous foraminifera in the upper few centimeters, but these disappear throughout most of the Holocene, suggesting more open water in that time period than present. In the sediments representing the end of the last glacial period (dated at ~11,500-14,000 calibrated years B.P. (cal B.P.)) a calcareous fauna with an abundant planktic foraminiferal fauna suggests a return to almost permanent ice cover, much like the central Arctic today. Together with the foraminifera there was also abundant ice-rafted debris (IRD) in both cores between 12,000 cal B.P. and ~14,000 cal B.P., but those units are of different ages between cores, suggesting different events. The IRD in both cores appears to have the same magnetic and chemical signals, but their origins cannot be determined exactly until clay mineralogy is completed. There is abundant organic debris in both cores below the IRD units: the organics in core 750 are very diffuse and not visually identifiable, but the organic material in core 124 is clearly identifiable with terrestrial root fragments; these are 14C dated at over 37,000 years B.P. This is a marine unit as it also has glacial front foraminifera in the sediment with the organic debris that must have been originating from subglacial streams. The seismic and multibeam data both indicate glaciers did not cross the core 124 site.

Aboveground community and species-specific plant biomass from the Jena Experiment (Dominance Experiment, year 2007)

This data set contains aboveground community plant biomass (Sown plant community, Weed plant community, Dead plant material, and Unidentified plant material; all measured in biomass as dry weight) and species-specific biomass from the sown species of the dominance experiment plots of a large grassland biodiversity experiment (the Jena Experiment; see further details below). In the dominance experiment, 206 grassland plots of 3.5 x 3.5 m were established from a pool of 9 plant species that can be dominant in semi-natural grassland communities of the study region. 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, 3, 4, 6, and 9 species). Plots were maintained by bi-annual weeding and mowing. Aboveground community biomass was harvested twice in May and August 2007 on all experimental plots of the dominance experiment. This was done by clipping the vegetation at 3 cm above ground in two rectangles of 0.2 x 0.5 m per experimental plot. The location of these rectangles was assigned by random selection of coordinates within the central area of the plots (excluding an outer edge of 50cm). The positions of the rectangles within plots were identical for all plots. The harvested biomass was sorted into categories: individual species for the sown plant species, weed plant species (species not sown at the particular plot), detached dead plant material, and remaining plant material that could not be assigned to any category. All biomass was dried to constant weight (70°C, >= 48 h) and weighed. Sown plant community biomass was calculated as the sum of the biomass of the individual sown species. The mean of both samples per plot and the individual measurements are provided in the data file. Overall, analyses of the community biomass data have identified species richness and the presence of particular species as an important driver of a positive biodiversity-productivity relationship.

Aboveground community and species-specific plant biomass from the Jena Experiment (Dominance Experiment, time series since 2002)

This data set comprises a time series of aboveground community plant biomass (Sown plant community, Weed plant community, Dead plant material, and Unidentified plant material; all measured in biomass as dry weight) and species-specific biomass from the sown species of the dominance experiment plots of a large grassland biodiversity experiment (the Jena Experiment; see further details below). In the dominance experiment, 206 grassland plots of 3.5 x 3.5 m were established from a pool of 9 species that can be dominant in semi-natural grassland communities of the study region. 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, 3, 4, 6, and 9 species). Plots were maintained by bi-annual weeding and mowing. Aboveground community biomass was harvested twice a year, generally in May and August (in 2002 only once in September) on all experimental plots of the dominance experiment. This was done by clipping the vegetation at 3 cm above ground in two rectangles of 0.2 x 0.5 m per experimental plot. The location of these rectangles was assigned by random selection of new coordinates every year within the central area of the plots (excluding an outer edge of 50cm). The positions of the rectangles within plots were identical for all plots. The harvested biomass was sorted into categories: individual species for the sown plant species, weed plant species (species not sown at the particular plot), detached dead plant material, and remaining plant material that could not be assigned to any category. Biomass was dried to constant weight (70°C, >= 48 h) and weighed. Sown plant community biomass was calculated as the sum of the biomass of the individual sown species. The mean of both samples per plot and the individual measurements are provided in the data file. Overall, analyses of the community biomass data have identified species richness and the presence of particular species as an important driver of a positive biodiversity-productivity relationship.