Biodiversity continues to decline in the face of increasing anthropogenic pressures such as habitat destruction, exploitation, pollution and introduction of alien species. Existing global databases of species’ threat status or population time series are dominated by charismatic species. The collation of datasets with broad taxonomic and biogeographic extents, and that support computation of a range of biodiversity indicators, is necessary to enable better understanding of historical declines and to project – and avert – future declines. We describe and assess a new database of more than 1.6 million samples from 78 countries representing over 28,000 species, collated from existing spatial comparisons of local-scale biodiversity exposed to different intensities and types of anthropogenic pressures, from terrestrial sites around the world. The database contains measurements taken in 208 (of 814) ecoregions, 13 (of 14) biomes, 25 (of 35) biodiversity hotspots and 16 (of 17) megadiverse countries. The database contains more than 1% of the total number of all species described, and more than 1% of the described species within many taxonomic groups – including flowering plants, gymnosperms, birds, mammals, reptiles, amphibians, beetles, lepidopterans and hymenopterans. The dataset, which is still being added to, is therefore already considerably larger and more representative than those used by previous quantitative models of biodiversity trends and responses. The database is being assembled as part of the PREDICTS project (Projecting Responses of Ecological Diversity In Changing Terrestrial Systems – http://www.predicts.org.uk). We make site-level summary data available alongside this article. The full database will be publicly available in 2015.

The PREDICTS project—Projecting Responses of Ecological Diversity In Changing Terrestrial Systems (www.predicts.org.uk)—has collated from published studies a large, reasonably representative database of comparable samples of biodiversity from multiple sites that differ in the nature or intensity of human impacts relating to land use. We have used this evidence base to develop global and regional statistical models of how local biodiversity responds to these measures. We describe and make freely available this 2016 release of the database, containing more than 3.2 million records sampled at over 26,000 locations and representing over 47,000 species. We outline how the database can help in answering a range of questions in ecology and conservation biology. To our knowledge, this is the largest and most geographically and taxonomically representative database of spatial comparisons of biodiversity that has been collated to date; it will be useful to researchers and international efforts wishing to model and understand the global status of biodiversity.

Abstract:Carbon and nitrogen stable isotope ratios (δ13C and δ15N) have been used to study the structure of food webs. However, few studies have examined how a terrestrial food web can be depicted by this technique. We measured δ13C and δ15N in various consumers of four trophic groups (detritivores, herbivores, omnivores and predators), including vertebrates and invertebrates (14 orders, ≥24 families), as well as canopy and understorey leaves in a tropical rain forest in Malaysia. We found that δ13C and δ15N of the consumers differed significantly among the trophic groups. The predators had significantly higher δ13C than the herbivores, and were similar in δ13C to the detritivores, suggesting that most predators examined depend largely on below-ground food webs. δ15N was higher in predators than detritivores by about 3‰. The comparison of δ13C in plant materials and herbivores suggests that most herbivores are dependent on C fixed in the canopy layers. The vertebrates had significantly higher δ15N and δ13C than the invertebrates of the same trophic group, likely reflecting differences in the physiological processes and/or feeding habits. This study indicates that stable isotope techniques can help better understanding of the terrestrial food webs in terms of both trophic level and the linkage of above- and below-ground systems.

High-strength and ultra-low-permeability concrete (HSULPC) is thought to be useful as a radioactive waste package. Thus, a high confining ability is desirable.For cementitious materials, sealing of cracks may occur in water due to the precipitation of calcium compounds. This can affect the confining ability. In this study, the sealing of a crack in HSULPC in water was investigated using microfocus X-ray computed tomography (CT). The sealing by precipitation occurred only around the end of the specimen. Sealed regions of the crack were identified using three-dimensional image registration and CT image subtraction of images obtained for the specimen before and after it was immersed in water to evaluate temporal changes of the sealing deposits in the crack. The sealing deposits increased as the HSULPC specimen was kept in water longer. It was concluded that cracks in HSULPC in water are sealed by precipitation.

Triaxial tests were conducted under confining pressures of 115 MPa at 295 K using an ultra-compact triaxial cell. The samples were held for 24 h under the target consolidation pressure, and then constant strain-rate compression was applied measuring permeability. The structural changes were measured by thin section image analysis and micro-focus X-ray computed tomography. For the Shikotsu welded tuff, the permeability decreased monotonously with axial compression. The decrease ratio of permeability increased with confining pressure mainly due to pore collapse. An equation representing the post-compression permeability with confining pressure was proposed. For the Kimachi sandstone, the permeability first decreased with increasing axial stress, then began to increase when the total lateral strain recovered its value before the application of confining pressure, and then maintained an almost constant value in the post-peak region.The minimum and final permeability decreased with increasing confining pressure mainly due to compaction and large plastic deformation of clay cementing materials. The final permeability was larger under small confining pressures and smaller under high confining pressures than the permeability before axial compression. Based on these observations, new equations were proposed representing the minimum and stable permeability and the strain at the permeability values with confining pressure. For the Inada granite, the tendency of permeability change during axial compression was almost the same as for the Kimachi sandstone. A new equation representing the minimum permeability mainly due to elastic deformation as a function of the confining pressure was proposed. The final permeability was larger than that before compression, and the permeability decreased with smaller confining pressure mainly due to a decrease in the number and width of rupture planes and the absence of axial cracks from biotite. The permeability, however, increased under larger confining pressures mainly due to the formation of subrupture planes caused by the high stress concentration at the rough and stiff rupture plane under large confining pressure.