| 1. |
- Bommarco, Riccardo, et al.
(author)
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Genetic and phenotypic differences between thistle populations in response to habitat and weed management practices
- 2010
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In: Biological Journal of the Linnean Society. - : Oxford University Press (OUP). - 0024-4066 .- 1095-8312. ; 99:4, s. 797-807
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Journal article (peer-reviewed)abstract
- Rapid evolutionary change is increasingly being recognized as commonplace, but the evolutionary consequences for species and ecosystems under human-induced selection regimes have not been explored in detail, although many species occur in such environments. In a common garden experiment and with amplified fragment length polymorphism markers, we examined whether genetic differentiation has taken place between spatially intermixed populations of creeping thistles Cirsium arvense (Asteraceae) collected from a natural habitat (maritime shores), a semi-natural habitat (road verges) and arable fields under two management regimes: conventional and organic farming. Populations of C. arvense have altered genetically and locally adapted their growth patterns with changed land use. Although plants from different habitats showed similar total biomass production, shoot and root production was higher for maritime populations, suggesting selection for increased competitive ability. Competitive ability then declined in the order semi-natural, conventional farms and organic farms. Thistles in arable fields may be more selected for tolerance against disturbances from herbicides and mechanical weed control. In addition, early shoot sprouting and genetic analysis showed differentiation between plants originating from conventional farms and farms that were converted to organic 9–30 years ago, suggesting some adaptation to altered crop cultivation practices
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| 2. |
- Bommarco, Riccardo, et al.
(author)
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Outbreak suppression by predators depends on spatial distribution of prey
- 2007
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In: Ecological Modelling. - : Elsevier BV. - 0304-3800 .- 1872-7026. ; 201:2, s. 163-170
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Journal article (peer-reviewed)abstract
- The capacity of a predator population to suppress a prey population that varies in abundance and spatial distribution is explored in a lattice simulation model. The model is based on empirically derived parameters for particular species. Within season predation by Pterostichus cupreus (Coleoptera: Carabidae) of varying densities and distributions of the prey Rhopalosiphum padi (Homoptera: Aphididae) in spring cereals was simulated. From these spatially explicit simulations prey population suppression was found to be largely dependent on the spatial distribution of the prey. A possible mechanism was that high degrees of prey aggregation provided refuge for the prey that, when aggregated, escaped detection by P. cupreus. In contrast, P. cupreus was found to efficiently suppress incipient outbreaks for evenly distributed prey populations, even at high prey densities. A higher predator density compensated for the lowered control ability of the predators for highly aggregated prey populations and hastened the decline of the prey population.
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| 3. |
- Lundin, Ola, et al.
(author)
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Neonicotinoid Insecticides and Their Impacts on Bees: A Systematic Review of Research Approaches and Identification of Knowledge Gaps.
- 2015
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In: PLoS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 10:8
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Journal article (peer-reviewed)abstract
- It has been suggested that the widespread use of neonicotinoid insecticides threatens bees, but research on this topic has been surrounded by controversy. In order to synthesize which research approaches have been used to examine the effect of neonicotinoids on bees and to identify knowledge gaps, we systematically reviewed research on this subject that was available on the Web of Science and PubMed in June 2015. Most of the 216 primary research studies were conducted in Europe or North America (82%), involved the neonicotinoid imidacloprid (78%), and concerned the western honey bee Apis mellifera (75%). Thus, little seems to be known about neonicotinoids and bees in areas outside Europe and North America. Furthermore, because there is considerable variation in ecological traits among bee taxa, studies on honey bees are not likely to fully predict impacts of neonicotinoids on other species. Studies on crops were dominated by seed-treated maize, oilseed rape (canola) and sunflower, whereas less is known about potential side effects on bees from the use of other application methods on insect pollinated fruit and vegetable crops, or on lawns and ornamental plants. Laboratory approaches were most common, and we suggest that their capability to infer real-world consequences are improved when combined with information from field studies about realistic exposures to neonicotinoids. Studies using field approaches often examined only bee exposure to neonicotinoids and more field studies are needed that measure impacts of exposure. Most studies measured effects on individual bees. We suggest that effects on the individual bee should be linked to both mechanisms at the sub-individual level and also to the consequences for the colony and wider bee populations. As bees are increasingly facing multiple interacting pressures future research needs to clarify the role of neonicotinoids in relative to other drivers of bee declines.
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| 4. |
- Wootton, Kate, et al.
(author)
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Beyond body size-new traits for new heights in trait-based modelling of predator-prey dynamics
- 2022
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In: PLOS ONE. - : Public Library of Science. - 1932-6203. ; 17:7 July
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Journal article (peer-reviewed)abstract
- Food webs map feeding interactions among species, providing a valuable tool for understanding and predicting community dynamics. Using species' body sizes is a promising avenue for parameterizing food-web models, but such approaches have not yet been able to fully recover observed community dynamics. Such discrepancies suggest that traits other than body size also play important roles. For example, differences in species' use of microhabitat or non-consumptive effects of intraguild predators may affect dynamics in ways not captured by body size. In Laubmeier et al. (2018), we developed a dynamic food-web model incorporating microhabitat and non-consumptive predator effects in addition to body size, and used simulations to suggest an optimal sampling design of a mesocosm experiment to test the model. Here, we perform the mesocosm experiment to generate empirical timeseries of insect herbivore and predator abundance dynamics. We minimize least squares error between the model and time-series to determine parameter values of four alternative models, which differ in terms of including vs excluding microhabitat use and non-consumptive predator-predator effects. We use both statistical and expert-knowledge criteria to compare the models and find including both microhabitat use and non-consumptive predatorpredator effects best explains observed aphid and predator population dynamics, followed by the model including microhabitat alone. This ranking suggests that microhabitat plays a larger role in driving population dynamics than non-consumptive predator-predator effects, although both are clearly important. Our results illustrate the importance of additional traits alongside body size in driving trophic interactions. They also point to the need to consider trophic interactions and population dynamics in a wider community context, where non-trophic impacts can dramatically modify the interplay between multiple predators and prey. Overall, we demonstrate the potential for utilizing traits beyond body size to improve traitbased models and the value of iterative cycling between theory, data and experiment to hone current insights into how traits affect food-web dynamics. © 2022 Wootton et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
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| 5. |
- Birkhofer, Klaus, et al.
(author)
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A framework to identify indicator species for ecosystem services in agricultural landscapes
- 2018
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In: Ecological Indicators. - : Elsevier BV. - 1470-160X .- 1872-7034. ; 91, s. 278-286
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Journal article (peer-reviewed)abstract
- Improving our understanding of the relationships between biodiversity and the delivery of ecosystem services is crucial for the development of sustainable agriculture. We introduce a novel framework that is based on the identification of indicator species for single or multiple ecosystem services across taxonomic groups based on indicator species analyses. We utilize multi-species community data (unlike previous single species approaches) without giving up information about the identity of species in our framework (unlike previous species richness approaches). We compiled a comprehensive community dataset including abundances of 683 invertebrate, vertebrate and plant species to identify indicator species that were either positively or negatively related to biological control, diversity of red-listed species or crop yield in agricultural landscapes in southern Sweden. Our results demonstrate that some taxonomic groups include significantly higher percentages of indicator species for these ecosystem services. Spider communities for example included a higher percentage of significant positive indicator species for biological control than ground or rove beetle communities. Bundles of indicator species for the analysed ecosystem service potentials usually included species that could be linked to the respective ecosystem service based on their functional role in local communities. Several of these species are conspicuous enough to be monitored by trained amateurs and could be used in bundles that are either crucial for the provision of individual ecosystem services or indicate agricultural landscapes with high value for red-listed species or crop yields. The use of bundles of characteristic indicator species for the simultaneous assessment of ecosystem services may reduce the amount of labour, time and cost in future assessments. In addition, future analysis using our framework in other ecosystems or with other subsets of ecosystem services and taxonomic groups will improve our understanding of service-providing species in local communities. In any case, expert knowledge is needed to select species from the identified subsets of significant indicator species and these species should be validated by existing data or additional sampling prior to being used for ecosystem service monitoring.
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| 6. |
- Birkhofer, Klaus, et al.
(author)
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Relationships between multiple biodiversity components and ecosystem services along a landscape complexity gradient
- 2018
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In: Biological Conservation. - : Elsevier BV. - 0006-3207 .- 1873-2917. ; 218, s. 247-253
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Journal article (peer-reviewed)abstract
- The assessment of effects of anthropogenic disturbance on biodiversity (BD) and ecosystem services (ES) and their relationships are key priorities of the Intergovernmental Panel for Biodiversity and Ecosystem Services. Agricultural landscapes and their associated BD provide multiple ES and it is crucial to understand how relationships between ES and BD components change along gradients of landscape complexity. In this study, we related eight ES potentials to the species richness of five invertebrate, vertebrate and plant taxonomic groups in cereal farming systems. The landscape complexity gradient ranged from areas dominated by annually tilled arable land to areas with high proportions of unfertilized, non-rotational pastures and uncultivated field borders. We show that after accounting for landscape complexity relationships between yield and bird richness or biological control became more positive, but relationships between bird richness and biological control became less positive. The relationship between bird and plant richness turned from positive to negative. Multidiversity (overall biodiversity), was positively related to landscape complexity, whereas multifunctionality (overall ES provision), was not significantly related to either one of these. Our results suggest that multidiversity can be promoted by increasing landscape complexity; however; we found no support for a simultaneous increase of several individual ES, BD components or multifunctionality. These results challenge the assumption that bio-diversity-friendly landscape management will always simultaneously promote multiple ES in agricultural landscapes. Future studies need to verify this pattern by using multi-year data, larger sets of ES and BD components and a study design that is appropriate to address larger spatial scales and relationships in several regions.
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| 7. |
- Clough, Yann, et al.
(author)
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Density of insect-pollinated grassland plants decreases with increasing surrounding land-use intensity
- 2014
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In: Ecology Letters. - : Wiley. - 1461-023X .- 1461-0248. ; 17:9, s. 1168-1177
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Journal article (peer-reviewed)abstract
- Pollinator declines have raised concerns about the persistence of plant species that depend on insect pollination, in particular by bees, for their reproduction. The impact of pollinator declines remains unknown for species-rich plant communities found in temperate seminatural grasslands. We investigated effects of land-use intensity in the surrounding landscape on the distribution of plant traits related to insect pollination in 239 European seminatural grasslands. Increasing arable land use in the surrounding landscape consistently reduced the density of plants depending on bee and insect pollination. Similarly, the relative abundance of bee-pollination-dependent plants increased with higher proportions of non-arable agricultural land (e.g. permanent grassland). This was paralleled by an overall increase in bee abundance and diversity. By isolating the impact of the surrounding landscape from effects of local habitat quality, we show for the first time that grassland plants dependent on insect pollination are particularly susceptible to increasing land-use intensity in the landscape.
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| 8. |
- Garibaldi, Lucas A., et al.
(author)
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Wild Pollinators Enhance Fruit Set of Crops Regardless of Honey Bee Abundance
- 2013
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In: Science. - : American Association for the Advancement of Science (AAAS). - 0036-8075 .- 1095-9203. ; 339:6127, s. 1608-1611
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Journal article (peer-reviewed)abstract
- The diversity and abundance of wild insect pollinators have declined in many agricultural landscapes. Whether such declines reduce crop yields, or are mitigated by managed pollinators such as honey bees, is unclear. We found universally positive associations of fruit set with flower visitation by wild insects in 41 crop systems worldwide. In contrast, fruit set increased significantly with flower visitation by honey bees in only 14% of the systems surveyed. Overall, wild insects pollinated crops more effectively; an increase in wild insect visitation enhanced fruit set by twice as much as an equivalent increase in honey bee visitation. Visitation by wild insects and honey bees promoted fruit set independently, so pollination by managed honey bees supplemented, rather than substituted for, pollination by wild insects. Our results suggest that new practices for integrated management of both honey bees and diverse wild insect assemblages will enhance global crop yields.
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| 9. |
- Gonzalez-Varo, Juan P., et al.
(author)
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Combined effects of global change pressures on animal-mediated pollination
- 2013
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In: Trends in Ecology & Evolution. - : Elsevier BV. - 1872-8383 .- 0169-5347. ; 28:9, s. 524-530
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Journal article (peer-reviewed)abstract
- Pollination is an essential process in the sexual reproduction of seed plants and a key ecosystem service to human welfare. Animal pollinators decline as a consequence of five major global change pressures: climate change, landscape alteration, agricultural intensification, non-native species, and spread of pathogens. These pressures, which differ in their biotic or abiotic nature and their spatiotemporal scales, can interact in nonadditive ways (synergistically or antagonistically), but are rarely considered together in studies of pollinator and/or pollination decline. Management actions aimed at buffering the impacts of a particular pressure could thereby prove ineffective if another pressure is present. Here, we focus on empirical evidence of the combined effects of global change pressures on pollination, highlighting gaps in current knowledge and future research needs.
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| 10. |
- Lindborg, Regina, et al.
(author)
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How spatial scale shapes the generation and management of multiple ecosystem services
- 2017
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In: Ecosphere. - : Wiley. - 2150-8925. ; 8:4
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Journal article (peer-reviewed)abstract
- The spatial extent of ecological processes has consequences for the generation of ecosystem services related to them. However, management often fails to consider issues of scale when targeting ecological processes underpinning ecosystem services generation. Here, we present a framework for conceptualizing how the amount and spatial scale (here discussed in terms of extent) of management interventions alter interactions among multiple ecosystem services. First, we identify four types of responses of ecosystem service generation: linear, exponential, saturating, and sigmoid, and how these are related to the amount of management intervention at a particular spatial scale. Second, using examples from multiple ecosystem services in agricultural landscapes, we examine how the shape of these relationships can vary with the spatial scale at which the management interventions are implemented. Third, we examine the resulting scale-dependent consequences for trade-offs and synergies between ecosystem services as a consequence of interventions. Finally, to inform guidelines for management of multiple ecosystem services in real landscapes, we end with a discussion linking the theoretical relationships with how landscape configurations and placement of interventions can alter the scale at which synergies and trade-offs among services occur.
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