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  • 1. De Palma, Adriana
    et al.
    Abrahamczyk, Stefan
    Aizen, Marcelo A.
    Albrecht, Matthias
    Basset, Yves
    Bates, Adam
    Blake, Robin J.
    Boutin, Celine
    Bugter, Rob
    Connop, Stuart
    Cruz-Lopez, Leopoldo
    Cunningham, Saul A.
    Darvill, Ben
    Diekoetter, Tim
    Dorn, Silvia
    Downing, Nicola
    Entling, Martin H.
    Farwig, Nina
    Felicioli, Antonio
    Fonte, Steven J.
    Fowler, Robert
    Franzen, Markus
    Goulson, Dave
    Grass, Ingo
    Hanley, Mick E.
    Hendrix, Stephen D.
    Herrmann, Farina
    Herzog, Felix
    Holzschuh, Andrea
    Jauker, Birgit
    Kessler, Michael
    Knight, M. E.
    Kruess, Andreas
    Lavelle, Patrick
    Le Feon, Violette
    Lentini, Pia
    Malone, Louise A.
    Marshall, Jon
    Pachon, Eliana Martinez
    McFrederick, Quinn S.
    Morales, Carolina L.
    Mudri-Stojnic, Sonja
    Nates-Parra, Guiomar
    Nilsson, Sven G.
    Ockinger, Erik
    Osgathorpe, Lynne
    Parra-H, Alejandro
    Peres, Carlos A.
    Persson, Anna S.
    Petanidou, Theodora
    Poveda, Katja
    Power, Eileen F.
    Quaranta, Marino
    Quintero, Carolina
    Rader, Romina
    Richards, Miriam H.
    Roulston, T'ai
    Rousseau, Laurent
    Sadler, Jonathan P.
    Samnegård, Ulrika
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och botanik.
    Schellhorn, Nancy A.
    Schuepp, Christof
    Schweiger, Oliver
    Smith-Pardo, Allan H.
    Steffan-Dewenter, Ingolf
    Stout, Jane C.
    Tonietto, Rebecca K.
    Tscharntke, Teja
    Tylianakis, Jason M.
    Verboven, Hans A. F.
    Vergara, Carlos H.
    Verhulst, Jort
    Westphal, Catrin
    Yoon, Hyung Joo
    Purvis, Andy
    Predicting bee community responses to land-use changes: Effects of geographic and taxonomic biases2016Inngår i: Scientific Reports, ISSN 2045-2322, E-ISSN 2045-2322, Vol. 6, artikkel-id 31153Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Land-use change and intensification threaten bee populations worldwide, imperilling pollination services. Global models are needed to better characterise, project, and mitigate bees' responses to these human impacts. The available data are, however, geographically and taxonomically unrepresentative; most data are from North America and Western Europe, overrepresenting bumblebees and raising concerns that model results may not be generalizable to other regions and taxa. To assess whether the geographic and taxonomic biases of data could undermine effectiveness of models for conservation policy, we have collated from the published literature a global dataset of bee diversity at sites facing land-use change and intensification, and assess whether bee responses to these pressures vary across 11 regions (Western, Northern, Eastern and Southern Europe; North, Central and South America; Australia and New Zealand; South East Asia; Middle and Southern Africa) and between bumblebees and other bees. Our analyses highlight strong regionally-based responses of total abundance, species richness and Simpson's diversity to land use, caused by variation in the sensitivity of species and potentially in the nature of threats. These results suggest that global extrapolation of models based on geographically and taxonomically restricted data may underestimate the true uncertainty, increasing the risk of ecological surprises.

  • 2. Hudson, Lawrence N.
    et al.
    Hylander, Kristoffer
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och botanik.
    Samnegård, Ulrika
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och botanik. Lund University, Sweden.
    The database of the PREDICTS (Projecting Responses of Ecological Diversity In Changing Terrestrial Systems) project2017Inngår i: Ecology and Evolution, ISSN 2045-7758, E-ISSN 2045-7758, Vol. 7, nr 1, s. 145-188Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    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.

  • 3. Hudson, Lawrence N.
    et al.
    Newbold, Tim
    Contu, Sara
    Hill, Samantha L. L.
    Lysenko, Igor
    De Palma, Adriana
    Phillips, Helen R. P.
    Senior, Rebecca A.
    Bennett, Dominic J.
    Booth, Hollie
    Choimes, Argyrios
    Correia, David L. P.
    Day, Julie
    Echeverria-Londono, Susy
    Garon, Morgan
    Harrison, Michelle L. K.
    Ingram, Daniel J.
    Jung, Martin
    Kemp, Victoria
    Kirkpatrick, Lucinda
    Martin, Callum D.
    Pan, Yuan
    White, Hannah J.
    Aben, Job
    Abrahamczyk, Stefan
    Adum, Gilbert B.
    Aguilar-Barquero, Virginia
    Aizen, Marcelo A.
    Ancrenaz, Marc
    Arbelaez-Cortes, Enrique
    Armbrecht, Inge
    Azhar, Badrul
    Azpiroz, Adrian B.
    Baeten, Lander
    Baldi, Andras
    Banks, John E.
    Barlow, Jos
    Batary, Peter
    Bates, Adam J.
    Bayne, Erin M.
    Beja, Pedro
    Berg, Ake
    Berry, Nicholas J.
    Bicknell, Jake E.
    Bihn, Jochen H.
    Boehning-Gaese, Katrin
    Boekhout, Teun
    Boutin, Celine
    Bouyer, Jeremy
    Brearley, Francis Q.
    Brito, Isabel
    Brunet, Joerg
    Buczkowski, Grzegorz
    Buscardo, Erika
    Cabra-Garcia, Jimmy
    Calvino-Cancela, Maria
    Cameron, Sydney A.
    Cancello, Eliana M.
    Carrijo, Tiago F.
    Carvalho, Anelena L.
    Castro, Helena
    Castro-Luna, Alejandro A.
    Cerda, Rolando
    Cerezo, Alexis
    Chauvat, Matthieu
    Clarke, Frank M.
    Cleary, Daniel F. R.
    Connop, Stuart P.
    D'Aniello, Biagio
    da Silva, Pedro Giovani
    Darvill, Ben
    Dauber, Jens
    Dejean, Alain
    Diekoetter, Tim
    Dominguez-Haydar, Yamileth
    Dormann, Carsten F.
    Dumont, Bertrand
    Dures, Simon G.
    Dynesius, Mats
    Edenius, Lars
    Elek, Zoltan
    Entling, Martin H.
    Farwig, Nina
    Fayle, Tom M.
    Felicioli, Antonio
    Felton, Annika M.
    Ficetola, Gentile F.
    Filgueiras, Bruno K. C.
    Fonte, Steven J.
    Fraser, Lauchlan H.
    Fukuda, Daisuke
    Furlani, Dario
    Ganzhorn, Joerg U.
    Garden, Jenni G.
    Gheler-Costa, Carla
    Giordani, Paolo
    Giordano, Simonetta
    Gottschalk, Marco S.
    Goulson, Dave
    Gove, Aaron D.
    Grogan, James
    Hanley, Mick E.
    Hanson, Thor
    Hashim, Nor R.
    Hawes, Joseph E.
    Hebert, Christian
    Helden, Alvin J.
    Henden, John-Andre
    Hernandez, Lionel
    Herzog, Felix
    Higuera-Diaz, Diego
    Hilje, Branko
    Horgan, Finbarr G.
    Horvath, Roland
    Hylander, Kristoffer
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och botanik.
    Isaacs-Cubides, Paola
    Ishitani, Masahiro
    Jacobs, Carmen T.
    Jaramillo, Victor J.
    Jauker, Birgit
    Jonsell, Mats
    Jung, Thomas S.
    Kapoor, Vena
    Kati, Vassiliki
    Katovai, Eric
    Kessler, Michael
    Knop, Eva
    Kolb, Annette
    Koroesi, Adam
    Lachat, Thibault
    Lantschner, Victoria
    Le Feon, Violette
    LeBuhn, Gretchen
    Legare, Jean-Philippe
    Letcher, Susan G.
    Littlewood, Nick A.
    Lopez-Quintero, Carlos A.
    Louhaichi, Mounir
    Loevei, Gabor L.
    Lucas-Borja, Manuel Esteban
    Luja, Victor H.
    Maeto, Kaoru
    Magura, Tibor
    Mallari, Neil Aldrin
    Marin-Spiotta, Erika
    Marshall, E. J. P.
    Martinez, Eliana
    Mayfield, Margaret M.
    Mikusinski, Grzegorz
    Milder, Jeffrey C.
    Miller, James R.
    Morales, Carolina L.
    Muchane, Mary N.
    Muchane, Muchai
    Naidoo, Robin
    Nakamura, Akihiro
    Naoe, Shoji
    Nates-Parra, Guiomar
    Navarrete Gutierrez, Dario A.
    Neuschulz, Eike L.
    Noreika, Norbertas
    Norfolk, Olivia
    Noriega, Jorge Ari
    Noeske, Nicole M.
    O'Dea, Niall
    Oduro, William
    Ofori-Boateng, Caleb
    Oke, Chris O.
    Osgathorpe, Lynne M.
    Paritsis, Juan
    Parra-H, Alejandro
    Pelegrin, Nicolas
    Peres, Carlos A.
    Persson, Anna S.
    Petanidou, Theodora
    Phalan, Ben
    Philips, T. Keith
    Poveda, Katja
    Power, Eileen F.
    Presley, Steven J.
    Proenca, Vania
    Quaranta, Marino
    Quintero, Carolina
    Redpath-Downing, Nicola A.
    Reid, J. Leighton
    Reis, Yana T.
    Ribeiro, Danilo B.
    Richardson, Barbara A.
    Richardson, Michael J.
    Robles, Carolina A.
    Roembke, Joerg
    Romero-Duque, Luz Piedad
    Rosselli, Loreta
    Rossiter, Stephen J.
    Roulston, T'ai H.
    Rousseau, Laurent
    Sadler, Jonathan P.
    Safian, Szabolcs
    Saldana-Vazquez, Romeo A.
    Samnegård, Ulrika
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och botanik.
    Schueepp, Christof
    Schweiger, Oliver
    Sedlock, Jodi L.
    Shahabuddin, Ghazala
    Sheil, Douglas
    Silva, Fernando A. B.
    Slade, Eleanor M.
    Smith-Pardo, Allan H.
    Sodhi, Navjot S.
    Somarriba, Eduardo J.
    Sosa, Ramon A.
    Stout, Jane C.
    Struebig, Matthew J.
    Sung, Yik-Hei
    Threlfall, Caragh G.
    Tonietto, Rebecca
    Tothmeresz, Bela
    Tscharntke, Teja
    Turner, Edgar C.
    Tylianakis, Jason M.
    Vanbergen, Adam J.
    Vassilev, Kiril
    Verboven, Hans A. F.
    Vergara, Carlos H.
    Vergara, Pablo M.
    Verhulst, Jort
    Walker, Tony R.
    Wang, Yanping
    Watling, James I.
    Wells, Konstans
    Williams, Christopher D.
    Willig, Michael R.
    Woinarski, John C. Z.
    Wolf, Jan H. D.
    Woodcock, Ben A.
    Yu, Douglas W.
    Zaitsev, Andrey S.
    Collen, Ben
    Ewers, Rob M.
    Mace, Georgina M.
    Purves, Drew W.
    Scharlemann, Joern P. W.
    Purvis, Andy
    The PREDICTS database: a global database of how local terrestrial biodiversity responds to human impacts2014Inngår i: Ecology and Evolution, ISSN 2045-7758, E-ISSN 2045-7758, Vol. 4, nr 24, s. 4701-4735Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    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.

  • 4. Lemessa, Debissa
    et al.
    Samnegård, Ulrika
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och botanik.
    Hambäck, Peter A.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och botanik.
    Hylander, Kristoffer
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och botanik.
    Tree cover mediates the effect on rapeseed leaf damage of excluding predatory arthropods, but in an unexpected way2015Inngår i: Agriculture, Ecosystems & Environment, ISSN 0167-8809, E-ISSN 1873-2305, Vol. 211, s. 57-64Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Birds and predatory arthropods are often implicated in pest control, but their relative impact and how this is mediated by variation in tree cover requires elucidation. We excluded birds and ground predatory arthropods from rapeseed plants in 2.5 x 1 m plots in 26 homegardens in Ethiopia, leaving the same sized control plots. From six groups of plants in bird exclosure and control plots, respectively, three groups were excluded from ground predatory arthropods. Data on leaf damage were surveyed four times at weekly intervals. The tree cover and land-use composition within 100 x 100 m surrounding each plots were recorded in the field and from a satellite image within 200 and 500 m buffer zones. The results show that the mean leaf damage was higher on rapeseed plants from which predatory arthropods were excluded than on control plants. However, excluding birds had no or only a weak impact on leaf damage. The mean leaf damage within predatory arthropod exclosures decreased with increasing tree, forest and perennial cover but increased with increasing grazing land cover and annual crop cover, while on control plants it was low across the tree cover variation. This pattern may indicate the presence of a higher density of herbivores on rapeseed plants and also more predatory arthropods (i.e., to control them) in tree-poor homegardens compared to tree-rich homegardens. Hence, tree-poor homegardens in this landscape have sufficient habitat heterogeneity to support natural enemies to deliver significant pest control on rapeseed. Our results show that there was variation in the dynamics of pests and predatory arthropods across the tree cover variation, suggesting changes in landscape composition could affect the pest control services and the outcomes for local farmers.

  • 5.
    Samnegård, Ulrika
    Stockholms universitet, Naturvetenskapliga fakulteten, Botaniska institutionen.
    Bees in a landscape context: what do bees need and who needs them?2011Rapport (Annet vitenskapelig)
    Abstract [en]

    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.

  • 6.
    Samnegård, Ulrika
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och botanik.
    The impact of forest on pest damage, pollinators and pollination services in an Ethiopian agricultural landscape2016Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    The distribution of wild biodiversity in agroecosystems affect crop performance and yield in various ways. In this thesis I have studied the impact of wild biodiversity, in terms of trees and forest structures, on crop pests, pollinators and the pollination services provided in a heterogeneous landscape in southwestern Ethiopia. 

    Coffee, Coffea arabica, is a forest shrub native to Ethiopia and is grown in most wooded areas in the landscape where I conducted my studies. Wild coffee is still found in remote parts of the forests in the landscape. For my first paper, I surveyed pest damage on coffee in coffee forest sites, where some sites were situated in continuous forest and some in isolated forest patches. I found the variation in pest damage frequency to mainly be among coffee plants within a site, rather than among sites, which indicates the importance of local processes. However, some pests were clearly connected to the forest habitat, such as the olive baboon.

    In my second study, I surveyed pollinators visiting coffee flowers across a gradient of shade-tree structures. I found the semi-wild honeybee to be the dominating flower visitor. The abundance of the honeybee was not related to shade-tree structures, but to amount of coffee flower resources in the site. On the other hand, other pollinators, which included other bee species and hoverflies, were positively affected by more shade trees in the site.

    In my third study I investigated how the forest cover affected local bee communities in the agricultural landscape. Moreover, I investigated if this relationship differed between the dry and rainy season. The distribution of food resources for bees changes between the seasons, which may affect the bees. Most trees, fruit trees and coffee, which are patchy resources, flowers in the dry season, whereas most herbs and annual crops, which are more evenly spread resources, flowers during the rainy season. I found a clear turnover in bee species composition between the dry and rainy season, with more mobile species in the dry season. Increased forest cover in the surrounding landscape had a positive impact on bee abundance and species richness. However, the impact did not change between seasons.

    In my fourth study I evaluated the pollination success and pollen limitation of a common oil crop in the landscape in relation to forest cover. I found severe pollen limitation across the landscape, which may be related to the observed low bee abundances. The pollen limitation was not related to surrounding forest cover.

    In conclusion, I have found the forest and wooded habitats to impact several mobile animals and pathogens in our study landscape, which in turn affect people. However, there is large complexity in nature and general relationships between forest structures and all crop related organisms may be unlikely to find. Various species are dependent on different resources, at different spatial scales and are interacting with several other species. To develop management strategies for increased pollination services, for reduced pest damage or for conservation in the landscape, more species-specific knowledge is needed.

  • 7.
    Samnegård, Ulrika
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och botanik.
    Hambäck, Peter A.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och botanik.
    Eardley, Connal
    Nemomissa, Sileshi
    Hylander, Kristoffer
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och botanik.
    Turnover in bee species composition and functional trait distributions between seasons in a tropical agricultural landscape2015Inngår i: Agriculture, Ecosystems & Environment, ISSN 0167-8809, E-ISSN 1873-2305, Vol. 211, s. 185-194Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A comprehensive understanding of how spatial variation across landscapes regulates local abundances and species richness also needs to consider possible temporal changes in such relationships. In many tropical areas, the contrast between dry and rainy season is pronounced and the types and distributions of the main floral resources differ (herbs vs trees). This shift in resources could result in different pollinator abundances, species richness and trait compositions between seasons, as well as in how these components are spatially distributed. We compared the bee species composition between dry and rainy season in an agricultural mosaic landscape in southwestern Ethiopia, and analyzed it in relation to forest cover. We sampled bees for 67 days in the dry season and 86 days in the rainy season with pan and vane traps in 28 homegardens covering a gradient from low to high tree cover in the surrounding area. We found a clear shift in species composition between seasons, with more small bee species and more below-ground nesting bees in the rainy season compared to the dry season. The distribution of height at which the bees were foraging shifted between seasons with a higher proportion of the bees foraging at tree level in the dry season. Bee abundance and richness were generally positively affected by higher forest cover surrounding the homegardens, but there were no clear interaction effects between seasons, in contrast to our hypothesis. The clear turnover in species composition between seasons and the positive effect of forest cover show that mechanisms acting both at spatial and temporal scales are important in regulating local bee communities.

  • 8.
    Samnegård, Ulrika
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och botanik. Lund University, Sweden.
    Hambäck, Peter A.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och botanik.
    Lemessa, Debissa
    Nemomissa, Sileshi
    Hylander, Kristoffer
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och botanik.
    A heterogeneous landscape does not guarantee high crop pollination2016Inngår i: Proceedings of the Royal Society of London. Biological Sciences, ISSN 0962-8452, E-ISSN 1471-2954, Vol. 283, nr 1838, artikkel-id 20161472Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The expansion of pollinator-dependent crops, especially in the developing world, together with reports of worldwide pollinator declines, raises concern of possible yield gaps. Farmers directly reliant on pollination services for food supply often live in regions where our knowledge of pollination services is poor. In a manipulative experiment replicated at 23 sites across an Ethiopian agricultural landscape, we found poor pollination services and severe pollen limitation in a common oil crop. With supplementary pollination, the yield increased on average by 91%. Despite the heterogeneous agricultural matrix, we found a low bee abundance, which may explain poor pollination services. The variation in pollen limitation was unrelated to surrounding forest cover, local bee richness and bee abundance. While practices that commonly increase pollinators (restricted pesticide use, flower strips) are an integral part of the landscape, these elements are apparently insufficient. Management to increase pollination services is therefore in need of urgent investigation.

  • 9.
    Samnegård, Ulrika
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och botanik.
    Hambäck, Peter A.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och botanik.
    Nemomissa, Sileshi
    Hylander, Kristoffer
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och botanik.
    Dominance of the semi-wild honeybee as coffee pollinator across a gradient of shade-tree structure in Ethiopia2014Inngår i: Journal of Tropical Ecology, ISSN 0266-4674, E-ISSN 1469-7831, Vol. 30, s. 401-408Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    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.

  • 10.
    Samnegård, Ulrika
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och botanik.
    Hambäck, Peter A.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och botanik.
    Nemomissa, Sileshi
    Hylander, Kristoffer
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och botanik.
    Local and Regional Variation in Local Frequency of Multiple Coffee Pests Across a Mosaic Landscape in Coffea arabica's Native Range2014Inngår i: Biotropica, ISSN 0006-3606, E-ISSN 1744-7429, Vol. 46, nr 3, s. 276-284Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    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.

  • 11.
    Samnegård, Ulrika
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och botanik.
    Hambäck, Peter
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och botanik.
    Lemessa, Debissa
    Nemomissa, Sileshi
    Hylander, Kristoffer
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och botanik.
    A heterogeneous landscape does not guarantee high crop pollinationManuskript (preprint) (Annet vitenskapelig)
    Abstract [en]

    The expansion of pollinator-dependent crops, especially in the developing world, together with reports of world-wide pollinator declines, raises concern of possible yield gaps. Farmers directly reliant on pollination services for food supply often live in regions where our knowledge of pollination services is poor. In a manipulative experiment replicated at 23 sites across an Ethiopian agricultural landscape, we found poor pollination services and severe pollen limitation in a common oil crop. With supplementary pollination, the yield increased on average by 91%. Despite the heterogeneous agricultural matrix, we found a low bee abundance, which may explain poor pollination services. The variation in pollen limitation was unrelated to surrounding forest cover, local bee richness and bee abundance. While practices that commonly increase pollinators (e.g. organic farming, flower strips) are an integral part of the landscape, these elements are apparently insufficient. Management to increase pollination services is therefore in need of urgent investigation.

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