| 1. |
- Hudson, Lawrence N., et al.
(författare)
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The PREDICTS database : a global database of how local terrestrial biodiversity responds to human impacts
- 2014
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Ingår i: Ecology and Evolution. - : Wiley. - 2045-7758. ; 4:24, s. 4701-4735
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Tidskriftsartikel (refereegranskat)abstract
- 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 - ). We make site-level summary data available alongside this article. The full database will be publicly available in 2015.
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| 2. |
- Samnegård, Ulrika, 1985-
(författare)
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Bees in a landscape context : what do bees need and who needs them?
- 2011
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- The interaction between plant and pollinator is generally mutualistic. The plant becomes pollinated or gets its pollen grains dispersed and the pollinator gets food rewards consisting of nectar or pollen. Many plants and crops are dependent on pollinators for fruit set and must therefore have efficient pollinators in their surroundings. There are many groups of animals that include pollinating species; however, bees are often referred to as the most effective pollinating group. Their effectiveness is partly because of their dependence on floral food resources both for larval development and adult survival. In addition to high abundance, high diversity of bees has been shown to be important for effective and stable pollination services of crops and wild plants. The importance of identifying what is affecting the bee composition and distribution in a landscape is therefore obvious. In addition to food resources, bees need suitable nesting habitats for reproduction and often external substrates for the construction of brood cells. On Earth, there are bees on every continent except Antarctica and 17,500 species are so far identified (Michener 2007). Despite the high diversity of bees with great variation in food and nesting requirements one factor has been found to frequently explain the diversity of bees; heterogeneity. In general, on a regional scale, bee diversity increases with higher heterogeneity in the landscape. Highly heterogeneous environments, provides high diversity of food and nesting resources, which can support more species. However, bee communities will differ in their response to changes in the landscape depending on species composition, habitat and continent. Therefore knowledge about the bees’ basic ecology and life-history is important for interpreting results and planning conservation measures.
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| 3. |
- Samnegård, Ulrika, et al.
(författare)
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Dominance of the semi-wild honeybee as coffee pollinator across a gradient of shade-tree structure in Ethiopia
- 2014
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Ingår i: Journal of Tropical Ecology. - 0266-4674 .- 1469-7831. ; 30, s. 401-408
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Tidskriftsartikel (refereegranskat)abstract
- Mass-flowering plant species are often pollinated by social bees that are able to use the abundant resource by recruiting workers from their colonies. In this study we surveyed pollinators on the mass-flowering perennial crop coffee (Coffea arabica) in its native range in Ethiopia. Previous studies in areas where coffee is introduced often find the social honeybee, Apis mellifera, to be the dominant pollinator. In those areas, the bee-species composition visiting coffee varies with a higher bee diversity closer to forest or in less modified habitats. We surveyed pollinators of coffee under different shade-tree structures, by collecting hoverflies and bees landing on coffee flowers in 19 sites in south-west Ethiopia. We found the native honeybee (A. mellifera) to be the dominant visitor of coffee flowers in all sites. Honeybee abundance was not affected by the local shade-tree structure, but was positively affected by the amount of coffee flower resources. Other pollinators were positively affected by complex shade-tree structures. To conclude, the honeybee is clearly the dominant pollinator of coffee in Ethiopia along the whole shade-tree structure gradient. Its high abundance could be a consequence of the provision of traditional bee hives in the landscape, which are colonized by wild swarming honeybees.
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| 4. |
- Samnegård, Ulrika, et al.
(författare)
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Local and Regional Variation in Local Frequency of Multiple Coffee Pests Across a Mosaic Landscape in Coffea arabica's Native Range
- 2014
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Ingår i: Biotropica. - : Wiley. - 0006-3606 .- 1744-7429. ; 46:3, s. 276-284
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Tidskriftsartikel (refereegranskat)abstract
- Shaded coffee has been highlighted for its potential to conserve biodiversity, and thus perhaps also a diversity of natural enemies that could control pest organisms. In southwestern Ethiopia, coffee is grown in shade both in contiguous forests and in forest patches with native trees surrounded by open fields. We hypothesized that coffee grown in contiguous forests, which is the natural habitat for coffee (Coffea arabica) and its interacting organisms, would have less pest damage due to high protection by natural enemies. We surveyed pests on coffee plants in plots within contiguous forests (10 sites) and in forest patches (21 sites). In general, the variation in number of damaged or attacked leaves by individual insect or fungal pests was larger between plants than between plots, which suggests that very local conditions or processes are important. The spatial signals were generally weak. Coffee rust and coffee blotch miner tended to have lower infestation rates in accordance with our hypothesis, while fruit flies in ripe berries were more abundant in forest patches closer to contiguous forest. Based on interviews, olive baboons showed a clear dependency on contiguous forest habitat and were regarded as a problem only in contiguous forests and forest patches close to contiguous forests. In conclusion, we found no support for a generally stronger top-down control on coffee pests in sites within, or with connectivity to, contiguous moist afromontane forests in the native range of coffee.
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