5 research outputs found
Benchmarking plant diversity of Palaearctic grasslands and other open habitats
Abstract
Aims: Understanding fine-grain diversity patterns across large spatial extents is fundamental for macroecological research and biodiversity conservation. Using the GrassPlot database, we provide benchmarks of fine-grain richness values of Palaearctic open habitats for vascular plants, bryophytes, lichens and complete vegetation (i.e., the sum of the former three groups).
Location: Palaearctic biogeographic realm.
Methods: We used 126,524 plots of eight standard grain sizes from the GrassPlot database: 0.0001, 0.001, 0.01, 0.1, 1, 10, 100 and 1,000 m² and calculated the mean richness and standard deviations, as well as maximum, minimum, median, and first and third quartiles for each combination of grain size, taxonomic group, biome, region, vegetation type and phytosociological class.
Results: Patterns of plant diversity in vegetation types and biomes differ across grain sizes and taxonomic groups. Overall, secondary (mostly semi-natural) grasslands and natural grasslands are the richest vegetation type. The open-access file ”GrassPlot Diversity Benchmarks” and the web tool “GrassPlot Diversity Explorer” are now available online (https://edgg.org/databases/GrasslandDiversityExplorer) and provide more insights into species richness patterns in the Palaearctic open habitats.
Conclusions: The GrassPlot Diversity Benchmarks provide high-quality data on species richness in open habitat types across the Palaearctic. These benchmark data can be used in vegetation ecology, macroecology, biodiversity conservation and data quality checking. While the amount of data in the underlying GrassPlot database and their spatial coverage are smaller than in other extensive vegetation-plot databases, species recordings in GrassPlot are on average more complete, making it a valuable complementary data source in macroecology
Strong Constraints on the Rare Decays B-s(0) -> mu(+)mu(-) and B-0 -> mu(+)mu(-)
A search for B-s(0) -> mu(+)mu(-) and B-0 -> mu(+)mu(-) decays is performed using 1.0 fb(-1) of pp collision data collected at root s = 7 TeV with the LHCb experiment at the Large Hadron Collider. For both decays, the number of observed events is consistent with expectation from background and standard model signal predictions. Upper limits on the branching fractions are determined to be B(B-s(0) -> mu(+)mu(-)) mu(+)mu(-)) < 1.0(0.81) x 10(-9) at 95% (90%) confidence level
Measurement of relative branching fractions of B decays to psi(2S) and J/psi mesons
The relative rates of B-meson decays into J/psi and psi(2S) mesons are measured for the three decay modes in pp collisions recorded with the LHCb detector. The ratios of branching fractions (B) are measured to be B(B+ -> psi(2S)K+)/B(B+ -> J/psi K+) = 0.594 +/- 0.006(stat) +/- 0.016(syst) +/- 0.015(R-psi), B(B-0 -> psi(2S)K*(0))/B(B-0 -> J/psi K*(0)) = 0.476 +/- 0.014(stat) +/- 0.010(syst) +/- 0.012(R-psi), B(B-s(0) -> psi(2S)phi)/B(B-s(0) -> J/psi phi) = 0.489 +/- 0.026(stat) +/- 0.021(syst) +/- 0.012(R-psi), where the third uncertainty is from the ratio of the psi(2S) and J/psi branching fractions to mu(+)mu(-)
First Observation of the Decays (B)over-bar(0) -> D+K-pi(+)pi(-) and B- -> (DK-)-K-0 pi(+)pi(-)
First observations of the Cabibbo-suppressed decays (B) over bar (0) -> D+K-pi(+)pi(-) and B- -> (DK-)-K-0 pi(+)pi(-) are reported using 35 pb(-1) of data collected with the LHCb detector. Their branching fractions are measured with respect to the corresponding Cabibbo-favored decays, from which we obtain B((B) over bar (0) -> D+K-pi(+)pi(-))/B((B) over bar (0) -> D+pi(-)pi(+)pi(-) = (5.9 +/- 1.1 +/- 0.5) x 10(-2) and B(B- -> (DK-)-K-0 pi(+)pi(-))/B(B- -> D-0 pi(-)pi(+)pi(-)) = (0.9 +/- 1.3 +/- 0.9) x 10(-2), where the uncertainties are statistical and systematic, respectively. The B- -> (DK-)-K-0 pi(+)pi(-) decay is particularly interesting, as it can be used in a similar way to B- -> (DK-)-K-0 to measure the Cabibbo-Kobayashi-Maskawa phase gamma
Search for the rare decays B-s(0) -> mu(+)mu(-) and B-0 -> mu(+)mu(-)
A search for the decays B-s(0) -> mu(+)mu(-) and B-0 -> mu(+)mu(-) is performed with 0.37 fb(-1) of pp collisions at root s = 7 TeV collected by the LHCb experiment in 2011. The upper limits on the branching fractions are B(B-s(0) -> mu(+)mu(-)) mu(+)mu(-)) mu(+)mu(-)) mu(+)mu(-)) < 3.2 x 10(-9) at 95% confidence level