658 research outputs found
Biodiversity data in different land uses, for Mediterranean and dryland environments
No full textAbundance and occurrence data for species that underlie the publication 'Assessing the effects of land use on biodiversity in the world's drylands and Mediterranean environments' by Diego Garcia-Vega and Tim Newbold.<br
Site-level biodiversity estimates for sites in different land uses, for Mediterranean and dryland environments
No full textSite-level estimates of biodiversity (total abundance, species richness, Simpson diversity index, Berger-Parker dominance index and average species range size) that underlie the publication
'Assessing the effects of land use on biodiversity in the world's
drylands and Mediterranean environments' by Diego Garcia-Vega and Tim
Newbold
Development of climate tipping damage metric for life-cycle assessment - the influence of increased warming from the tipping
No full textPurpose: The multiple climate tipping points potential (MCTP) is a novel metric in life-cycle assessment (LCA). It addresses the contribution of greenhouse gas emissions to disturb those processes in the Earth system, which could pass a tipping point and thereby trigger large, abrupt and potentially irreversible changes. The MCTP, however, does not represent ecosystems damage. Here, we further develop this midpoint metric by linking it to losses of terrestrial species biodiversity at either local or global scales. Method: A mathematical framework was developed to translate midpoint impacts to temperature increase, first, and then to potential loss of species resulting from the temperature increase, using available data on the potentially disappeared fraction of species due to a unit change in global average temperature. Results and discussion: The resulting damage MCTP expresses the impacts on ecosystems quality in terms of potential loss of terrestrial species resulting from the contribution of GHG emissions to cross climatic tipping points. The MCTP values range from 2.3·10–17 to 1.1·10–15 PDF (potentially disappeared fraction of species) for the global scale and from 2.7·10–17 to 1.1·10–15 PDF per 1 kg of CO2 emitted for the local scale. They are time-dependent, and the largest values are found for emissions occurring between 2030 and 2045, generally declining for emissions occurring toward the end of the century. Conclusions: The developed metric complements existing damage-level metrics used in LCA, and its application is expected to be especially relevant for products where time-differentiation of emissions is possible. To enable direct comparisons between our damage MCTP and the damage caused by other environmental impacts or other climate-related impact categories, further efforts are needed to harmonize MCTP units with those of the compared damage metrics
A well-conserved Plasmodium falciparum var gene shows an unusual stage-specific transcript pattern
No full textThe var multicopy gene family encodes Plasmodium falciparum erythrocyte membrane protein 1 (PfEMP1) variant antigens, which, through their ability to adhere to a variety of host receptors, are thought to be important virulence factors. The predominant expression of a single cytoadherent PfEMP1 type on an infected red blood cell, and the switching between different PfEMP1 types to evade host protective antibody responses, are processes thought to be controlled at the transcriptional level. Contradictory data have been published on the timing of var gene transcription. Reverse transcription-polymerase chain reaction (RT-PCR) data suggested that transcription of the predominant var gene occurs in the later (pigmented trophozoite) stages, whereas Northern blot data indicated such transcripts only in early (ring) stages. We investigated this discrepancy by Northern blot, with probes covering a diverse var gene repertoire. We confirm that almost all var transcript types were detected only in ring stages. However, one type, the well-conserved varCSA transcript, was present constitutively in different laboratory parasites and does not appear to undergo antigenic variation. Although varCSA has been shown to encode a chondroitin sulphate A (CSA)-binding PfEMP1, we find that the presence of full-length varCSA transcripts does not correlate with the CSA-binding phenotype
Impact of Crop Type on Biodiversity Globally
No full textABSTRACT The negative impact of agricultural land on biodiversity is widely recognized. However, there remains a knowledge gap regarding the role of different crop types in maintaining biodiversity within the agricultural landscape. By extracting biodiversity data from global datasets and classifying different crop types, we quantified the contribution of different crop types to biodiversity. Our results indicate that biodiversity levels vary widely among crop types. We found a general loss of biodiversity when natural vegetation is converted to agricultural land, and highest losses in fiber crops, cereals and oil crops, and least in other crops (such as coffee or cocoa) and in mixed crops. In general, perennial crops retain more biodiversity than annual crops. Losses of biodiversity can be mitigated through mixed cropping of multiple crop types, especially by combining annual and perennial crops. The negative impact of converting natural vegetation to agriculture is greater in tropical than in nontropical areas, and hence, the import of commodities from these biodiversity‐rich regions may be particularly detrimental. Given the ongoing increase in biodiversity losses from global intensification and expansion of agricultural land, maintaining or restoring natural vegetation, rating the crop‐type‐specific biodiversity, diversifying crops, and preferring perennial over annual crops, particularly in the tropics, need to be better considered and implemented in global agri‐environmental schemes.National Key Research and Development Program of China https://doi.org/10.13039/501100012166National Natural Science Foundation of China https://doi.org/10.13039/501100001809China Scholarship Council https://doi.org/10.13039/501100004543Natural Environment Research Council https://doi.org/10.13039/50110000027
The PREDICTS database: a global database of how local terrestrial biodiversity responds to human impacts
No full textBiodiversity 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 – www.predicts.org.uk)
The database of the PREDICTS (Projecting Responses of Ecological Diversity In Changing Terrestrial Systems) Project Supporting File S1
No full textdatase
Rainout at the tennis courts, 1970.
No full textRainout at the tennis courts, 1970. The little boy is Daniel Timberlake, and the women are Mrs. Tim Timberlake and Mrs. J. S. Newbold
Traits influence responses to land-use and climate change in terrestrial vertebrates
No full textHuman activities have profoundly impacted global biodiversity. Currently, anthropogenic land-use and climate change figure among the major threats to the world’s fauna. However, not all species respond similarly to these pressures. Interspecific variability in responses to human threats is notably underpinned by the fact that different species possess different ecological characteristics, some of them allowing species to cope with environmental changes, while others confer a disadvantage to species in modified environments. Understanding what renders species sensitive to anthropogenic pressures is vital to inform and prioritise conservation efforts. Yet, in terrestrial vertebrates, a group for which ecological data are the most abundant, it remains unclear which traits are associated with higher sensitivity to human pressures. The aims of my thesis are to investigate whether and which traits are associated with land-use responses and climate-change sensitivity in terrestrial vertebrates, and to highlight some of the consequences for ecosystem functioning. I first assess the global availability of ecological trait data for terrestrial vertebrates, identifying understudied groups and regions (e.g., Central-African reptiles). I then show that, at global scales, disturbed land uses negatively impact the functional diversity of vertebrate assemblages. Further, I find that in all classes, higher sensitivity to land-use and climate change is associated with narrower ranges, smaller habitat breadth and inability to use human-modified habitats. Both land-use responses and climate-change sensitivity are unevenly distributed among dietary groups, highlighting potential food-web disruptions in assemblages under pressure. Finally, I show that land-use responses are influenced by species’ energetic requirements, so that energetic fluxes within vertebrate assemblages are likely modified under human-driven land-use change. Although the large-scale consequences of biodiversity changes for ecosystem functioning remain to be fully understood, my thesis highlights a compositional reshaping of vertebrate assemblages under human pressure and furthers our understanding of anthropogenic impacts on biodiversity
- …
