Functionally richer communities improve ecosystem functioning: Dung removal and secondary seed dispersal by dung beetles in the Western Palaearctic

Aim: In several ecosystems, the diversity of functional species traits has been shown to have a stronger effect on ecosystem functioning than taxonomic diversity alone. However, few studies have explored this idea at a large geographical scale. In a multisite experiment, we unravelled the relationship between ecosystem function and functional completeness of species assemblages using dung beetles as a model group, focusing on dung removal and secondary seed dispersal. Location: Seventeen grassland locations across the Western Palaearctic. Methods: We used a randomized block design with different exclosure types to control the dung and seed removing activities of individual functional groups of the local dung beetle assemblage. We classified dung beetle species according to resource specialization and into functional groups based on dung processing behaviour (dwellers, tunnellers, rollers) and body size (small, large). Additionally, we assessed the role of other soil macro‐invertebrates. By sampling the dung beetle community and measuring the remaining dung and seeds after the experiment, the impact of each functional group was estimated. Results: Dung beetle assemblages differed along a north–south and east–west gradient. Dwellers dominated northernmost sites, whereas at lower latitudes we observed more tunnellers and rollers indicating a functional shift. Resource specialists were more abundant in southern and eastern areas. Overall, functional group diversity enhanced dung removal. More dung (+46.9%) and seeds (+32.1%) were removed in the southern sites and tunnellers and rollers were more effective. At the northernmost sites, where tunnellers were scarce or absent, other soil macro‐invertebrates removed the majority of dung. Main conclusions: The conservation of functionally complete dung beetle assemblages is crucial to maintain the ecosystem functions provided by dung beetles. Given the latitudinal variation in functional group diversity, it is reasonable to expect compositional changes due to climate change. These changes could lead to increased dung removal and a higher secondary seed dispersal rate in northern regions

Dung beetle assemblages, dung removal and secondary seed dispersal: data from a large-scale, multi-site experiment in the Western Palaearctic

By manipulating faeces during feeding and breeding, dung beetles (Coleoptera: Scarabaeidae) fulfil important ecosystem functions in terrestrial ecosystems throughout the world. In a pan-European multi-site experiment (MSE), we estimated the ecosystem functions of dung removal and secondary seed dispersal by differing combinations of dung beetle functional groups. Therefore, we classified dung beetles into five functional groups according to their body size and dung manipulation method: dwellers, large and small tunnelers, and large and small rollers. Furthermore, we set up a dung beetle sampling database containing all sampled dung beetles during the project. By identifying dung beetle specimens to the species level, we obtained a detailed insight into the dung beetle communities at each study location. By establishing experimental plots allowing and inhibiting specific combinations of functional groups in the local dung beetle assemblage from removing dung and seeds, we estimated the role of each group in dung removal and secondary seed dispersal during a 4-week period. We performed all experiments in grazed (semi-)natural grasslands, and used different dung types (cattle, horse, sheep, goat or red deer) to match the herbivore species grazing in close vicinity of each of the study areas. Simultaneously, we sampled dung beetle assemblages by using pitfalls baited with the same dung types as used in the experiments. This data paper documents two datasets collected in the framework of this MSE project. All the experiments took place between 2013 and 2016 at 17 study sites in 10 countries and 11 biogeographic zones. The entire dung beetle sampling dataset was published as a sampling event dataset at GBIF. The dataset includes the sampling results of all 17 study sites, which contain 1,050 sampling events and 4,362 occurrence records of 94 species. The second dataset contains the results of the dung removal and secondary seed dispersal experiments in which we used 11 experimental treatments and the five dung types mentioned above. This experimental results dataset holds all experimental results of the MSE project (11,537 records), and was published in the online data repository Zenodo

MRD-Cl potential surfaces using balanced basis sets. IV. The H2 molecule and the H3 surface

The utility of midbond functions in molecular calculations was tested in two cases where the correct results are known: the H2 potential curve and the collinear H3 potential surface. For H2, a variety of basis sets both with and without bond functions was compared to the exact nonrelativistic potential curve of Kolos and Wolniewicz [J. Chem. Phys. 43, 2429 (1965)]. It was found that optimally balanced basis sets at two levels of quality were the double zeta single polarization plus sp bond function basis (BF1) and the triple zeta double polarization plus two sets of sp bond function basis (BF2). These gave bond dissociation energies De=4.7341 and 4.7368 eV, respectively (expt. 4.7477 eV). Four basis sets were tested for basis set super-position errors, which were found to be small relative to basis set incompleteness and therefore did not affect any conclusions regarding basis set balance. Basis sets BF1 and BF2 were used to construct potential surfaces for collinear H3, along with the corresponding basis sets DZ*P and TZ*PP which contain no bond functions. Barrier heights of 12.52, 10.37, 10.06, and 9.96 kcal/mol were obtained for basis sets DZ*P, TZ*PP, BF1, and BF2, respectively, compared to an estimated limiting value of 9.60 kcal/mol. Difference maps, force constants, and relative rms deviations show that the bond functions improve the surface shape as well as the barrier height

Diagnostic Software with WEB Interface for Teaching Purposes

This paper describes a diagnostic software package called Turbo Tester. It contains a variety of tools related to the area of digital test. The range of tools includes test generators, logic and fault simulators, test optimizer, hazard analyzer, built-in self-test simulators, and design error diagnosis tools. The range of compatible diagnostic tools forms, via their interaction and complementary operation, a homogeneous research environment, which provides good possibilities for experimental research

MRD Cl calculation of the first and second ionization potential of OH

Multireference Cl calculations are reported for OH(2Π). OH+ (3Σ-), and OH2+ (4Σ-) using several basis sets. Ionization potentials derived from the potential curves are compared to previous calculations and to experimental values. We show that the errors obtained from the calculations can be traced to the difficulty in obtaining an accurate treatment of the ionization energy of the oxygen atom. No experimental artifact needs to be invoked to explain the discrepancy with the experimental results

Ground beetles as predators of oilseed rape pests : incidence, spatio-temporal distributions and feeding

Non peer reviewe

Characterization of self-assembled bilayers: silver-alkanethiolates

Layered materials composed of silver-alkanethiolate units are characterized and compared to self-assembled alkanethiolate monolayers and thiolate-capped nanoparticles. A comprehensive infrared spectroscopy study is presented for silver-alkanethiolate materials having chain lengths varying from 7 to 18 carbon atoms. The high level of definition in these spectra will make this a benchmark system for comparisons to other metal thiolate systems. An X-ray diffraction study of these same materials is used to determine the tilt angle of the chains, which is very close to that reported for the thiolate monolayers on Ag(111). These results are combined with a thorough characterization of the AgSC12 material using X-ray photoelectron spectroscopy, electronic spectroscopy, differential scanning calorimetry, and solid-state NMR. Overall, this provides a detailed description of the structure, the thermal stability, and the high degree of conformational order in these materials, which have not previously been extensively characterized at these chain lengths.NRC publication: Ye

The self-assembly of a layered material: metal-alkanethiolate bilayers

Peer reviewed: YesNRC publication: Ye