| 1. |
- Karp, Daniel S., et al.
(författare)
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Crop pests and predators exhibit inconsistent responses to surrounding landscape composition
- 2018
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Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - : Proceedings of the National Academy of Sciences. - 1091-6490 .- 0027-8424. ; 115:33, s. 7863-7870
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Tidskriftsartikel (refereegranskat)abstract
- The idea that noncrop habitat enhances pest control and represents a win–win opportunity to conserve biodiversity and bolster yields has emerged as an agroecological paradigm. However, while noncrop habitat in landscapes surrounding farms sometimes benefits pest predators, natural enemy responses remain heterogeneous across studies and effects on pests are inconclusive. The observed heterogeneity in species responses to noncrop habitat may be biological in origin or could result from variation in how habitat and biocontrol are measured. Here, we use a pest-control database encompassing 132 studies and 6,759 sites worldwide to model natural enemy and pest abundances, predation rates, and crop damage as a function of landscape composition. Our results showed that although landscape composition explained significant variation within studies, pest and enemy abundances, predation rates, crop damage, and yields each exhibited different responses across studies, sometimes increasing and sometimes decreasing in landscapes with more noncrop habitat but overall showing no consistent trend. Thus, models that used landscape-composition variables to predict pest-control dynamics demonstrated little potential to explain variation across studies, though prediction did improve when comparing studies with similar crop and landscape features. Overall, our work shows that surrounding noncrop habitat does not consistently improve pest management, meaning habitat conservation may bolster production in some systems and depress yields in others. Future efforts to develop tools that inform farmers when habitat conservation truly represents a win–win would benefit from increased understanding of how landscape effects are modulated by local farm management and the biology of pests and their enemies. © 2018 National Academy of Sciences. All rights reserved.
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| 2. |
- Alexandridis, Nikolaos, et al.
(författare)
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Archetype models upscale understanding of natural pest control response to land-use change
- 2022
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Ingår i: Ecological Applications. - : Wiley. - 1051-0761 .- 1939-5582. ; 32:8
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Tidskriftsartikel (refereegranskat)abstract
- Control of crop pests by shifting host plant availability and natural enemy activity at landscape scales has great potential to enhance the sustainability of agriculture. However, mainstreaming natural pest control requires improved understanding of how its benefits can be realized across a variety of agroecological contexts. Empirical studies suggest significant but highly variable responses of natural pest control to land-use change. Current ecological models are either too specific to provide insight across agroecosystems, or too generic to guide management with actionable predictions. We suggest getting the full benefit of available empirical, theoretical and methodological knowledge, by combining trait-mediated understanding from correlative studies with the explicit representation of causal relationships achieved by mechanistic modeling. To link these frameworks, we adapt the concept of archetypes, or context-specific generalizations, from sustainability science. Similar responses of natural pest control to land-use gradients across cases that share key attributes, such as functional traits of focal organisms, indicate general processes that drive system behavior in a context-sensitive manner. Based on such observations of natural pest control, a systematic definition of archetypes can provide the basis for mechanistic models of intermediate generality that cover all major agroecosystems worldwide. Example applications demonstrate the potential for upscaling understanding and improving prediction of natural pest control, based on knowledge transfer and scientific synthesis. A broader application of this mechanistic archetype approach promises to enhance ecology's contribution to natural resource management across diverse regions and social-ecological contexts.
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| 3. |
- Kardum Hjort, Cecilia, et al.
(författare)
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Genomic divergence and a lack of recent introgression between commercial and wild bumblebees (Bombus terrestris)
- 2022
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Ingår i: Evolutionary Applications. - : Wiley. - 1752-4571. ; 15:3, s. 365-382
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Tidskriftsartikel (refereegranskat)abstract
- The global movement of bees for agricultural pollination services can affect local pollinator populations via hybridization. When commercial bumblebees are of the same species but of different geographic origin, intraspecific hybridization may result in beneficial integration of new genetic variation, or alternatively may disrupt locally adapted gene complexes. However, neither the existence nor the extent of genomic introgression and evolutionary divergence between wild and commercial bumblebees is fully understood. We obtained whole-genome sequencing data from wild and commercial Bombus terrestris collected from sites in Southern Sweden with and without long-term use of commercially imported B. terrestris. We search for evidence of introgression, dispersal and genome-wide differentiation in a comparative genomic analysis of wild and commercial bumblebees. Commercial B. terrestris were found in natural environments near sites where commercial bumblebees were used, as well as drifting wild B. terrestris in commercial bumblebee colonies. However, we found no evidence for widespread, recent genomic introgression of commercial B. terrestris into local wild conspecific populations. We found that wild B. terrestris had significantly higher nucleotide diversity (Nei's pi, π), while the number of segregating sites (Watterson's theta, θw) was higher in commercial B. terrestris. A highly divergent region on chromosome 11 was identified in commercial B. terrestris and found to be enriched with structural variants. The genes present in this region are involved in flight muscle contraction and structure and pathogen immune response, providing evidence for differing evolutionary processes operating in wild and commercial B. terrestris. We did not find evidence for recent introgression, suggesting that co-occurring commercial B. terrestris have not disrupted evolutionary processes in wild B. terrestris populations.
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| 4. |
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| 5. |
- Dänhardt, Juliana, et al.
(författare)
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Ekologiska fokusarealer i samverkan : Utvärdering av effekter på ekosystemtjänster, jordbruk och administration
- 2017
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- I den här studien utvärderar vi konsekvenserna av så kallat gemensamt genomförande av ekologiska fokusarealer enlig artikel 46:5 och 46:6 i EU:s direktstödsförordning. Genom bredare analyser beaktar vi även andra former av samverkan och justerade skötselvillkor. Att främja sammanhängande områden med ekologiskt fokus är en del av EU:s satsning på grön infrastruktur. Sverige tillämpar inte gemensamt genomförande i dagsläget. Ekologisk-ekonomisk modellering, workshop med jordbrukare och intervjuer med tjänstemän ligger till grund för studiens resultat. Fokus i våra analyser är effekter på pollinering och biologisk skadedjursbekämpning, båda ekosystemtjänster till nytta för jordbruket.Jordbrukare positiva till samverkan, tjänstemän befarar högre kostnaderGenerellt är de medverkande jordbrukarna positiva till samverkan. Tydligare och mer konkret koppling mellan godkända fokusarealer, skötselvillkor och miljönytta behövs dock för att skapa acceptans hos jordbrukarna. Tjänstemän med erfarenhet av samverkan är generellt positiva, medan personer utan erfarenhet är mer tveksamma. På svenska myndigheter befaras ökade transaktionskostnader, trots att fungerande exempel på samverkan i Europa finns. Vi rekommenderar att inspiration och kunskap hämtas från dessa lyckade exempel.Små miljöeffekter med dagens fokusarealerAtt med dagens regelverk införa gemensamt genomförande av ekologiska fokusarealer ger små miljöeffekter. Miljöeffekten förblir svag eftersom möjligheten att välja fokusarealer med låg miljöeffekt kvarstår, och eftersom generösa viktningsfaktorer minskar den faktiskt avsatta arealen av fokusarealer med högre miljönytta. Dessutom finns incitament att placera fokusarealerna på lågproduktiv mark, där behovet av fokusarealer som gynnar ekosystemtjänster är lägre. I dag godkänns också fokusarealer som ingår i det normala brukandet, vilket skapar dödvikt. Våra modeller visar att möjligheten till samverkan inte löser dessa problem.Bättre miljöeffekt med rätt fokusarealer och krav på kvalitetFör att uppnå en bättre miljöeffekt behövs en utformning av reglerna som premierar de mest miljöeffektiva fokusarealerna. Först och främst bör menyn av fokusarealer innehålla miljöeffektiva åtgärder. Dessutom bör viktningssystemet omvärderas så att den mest effektiva fokusarealen används som referens. Slutligen bör placeringen av ekologiska fokusarealer göras i ett landskapsperspektiv för att säkerställa fokusarealernas bidrag till grön infrastruktur. På gårdsnivå bör fokusarealerna genom information och rådgivning styras till platser där potentialen för miljönytta är störst, exempelvis intill grödor som gynnas av pollinering och biologisk skadedjursbekämpning. Ett effektivt sätt att gynna just dessa ekosystemtjänster vore att begränsa menyn av valbara fokusarealer till träda och obrukade fältkanter och samtidigt ha krav på att så in blommande växter.
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| 6. |
- Lindström, Sandra A M, et al.
(författare)
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Experimental evidence that honeybees depress wild insect densities in a flowering crop
- 2016
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Ingår i: Proceedings of the Royal Society B: Biological Sciences. - : The Royal Society. - 0962-8452 .- 1471-2954. ; 283:1843
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Tidskriftsartikel (refereegranskat)abstract
- While addition of managed honeybees (Apis mellifera) improves pollination of many entomophilous crops, it is unknown if it simultaneously suppresses the densities of wild insects through competition. To investigate this, we added 624 honeybee hives to 23 fields of oilseed rape (Brassica napus L.) over 2 years and made sure that the areas around 21 other fields were free from honeybee hives. We demonstrate that honeybee addition depresses the densities of wild insects (bumblebees, solitary bees, hoverflies, marchflies, other flies, and other flying and flower-visiting insects) even in a massive flower resource such as oilseed rape. The effect was independent of the complexity of the surrounding landscape, but increased with the size of the crop field, which suggests that the effect was caused by spatial displacement of wild insects. Our results have potential implications both for the pollination of crops (if displacement of wild pollinators offsets benefits achieved by adding honeybees) and for conservation of wild insects (if displacement results in negative fitness consequences).
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| 7. |
- Senapathi, Deepa, et al.
(författare)
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Wild insect diversity increases inter-annual stability in global crop pollinator communities
- 2021
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Ingår i: Royal Society of London. Proceedings B. Biological Sciences. - : The Royal Society. - 1471-2954 .- 0962-8452. ; 288:1947
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Tidskriftsartikel (refereegranskat)abstract
- While an increasing number of studies indicate that the range, diversity and abundance of many wild pollinators has declined, the global area of pollinator-dependent crops has significantly increased over the last few decades. Crop pollination studies to date have mainly focused on either identifying different guilds pollinating various crops, or on factors driving spatial changes and turnover observed in these communities. The mechanisms driving temporal stability for ecosystem functioning and services, however, remain poorly understood. Our study quantifies temporal variability observed in crop pollinators in 21 different crops across multiple years at a global scale. Using data from 43 studies from six continents, we show that (i) higher pollinator diversity confers greater inter-annual stability in pollinator communities, (ii) temporal variation observed in pollinator abundance is primarily driven by the three-most dominant species, and (iii) crops in tropical regions demonstrate higher inter-annual variability in pollinator species richness than crops in temperate regions. We highlight the importance of recognizing wild pollinator diversity in agricultural landscapes to stabilize pollinator persistence across years to protect both biodiversity and crop pollination services. Short-term agricultural management practices aimed at dominant species for stabilizing pollination services need to be considered alongside longer term conservation goals focussed on maintaining and facilitating biodiversity to confer ecological stability.
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| 8. |
- Pontarp, Mikael, et al.
(författare)
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Evolutionary plant–pollinator responses to anthropogenic land-use change : impacts on ecosystem services
- 2024
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Ingår i: Biological Reviews. - 1464-7931. ; 99:2, s. 372-389
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Tidskriftsartikel (refereegranskat)abstract
- Agricultural intensification at field and landscape scales, including increased use of agrochemicals and loss of semi-natural habitats, is a major driver of insect declines and other community changes. Efforts to understand and mitigate these effects have traditionally focused on ecological responses. At the same time, adaptations to pesticide use and habitat fragmentation in both insects and flowering plants show the potential for rapid evolution. Yet we lack an understanding of how such evolutionary responses may propagate within and between trophic levels with ensuing consequences for conservation of species and ecological functions in agroecosystems. Here, we review the literature on the consequences of agricultural intensification on plant and animal evolutionary responses and interactions. We present a novel conceptualization of evolutionary change induced by agricultural intensification at field and landscape scales and emphasize direct and indirect effects of rapid evolution on ecosystem services. We exemplify by focusing on economically and ecologically important interactions between plants and pollinators. We showcase available eco-evolutionary theory and plant–pollinator modelling that can improve predictions of how agricultural intensification affects interaction networks, and highlight available genetic and trait-focused methodological approaches. Specifically, we focus on how spatial genetic structure affects the probability of propagated responses, and how the structure of interaction networks modulates effects of evolutionary change in individual species. Thereby, we highlight how combined trait-based eco-evolutionary modelling, functionally explicit quantitative genetics, and genomic analyses may shed light on conditions where evolutionary responses impact important ecosystem services.
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| 9. |
- Ekroos, Johan, et al.
(författare)
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Embedding Evidence on Conservation Interventions Within a Context of Multilevel Governance
- 2017
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Ingår i: Conservation Letters. - : Wiley. - 1755-263X. ; 10:1, s. 139-145
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Tidskriftsartikel (refereegranskat)abstract
- We outline a conceptual strategy for implementing conservation interventionsin a multiscale, multiactor, and multilevel governance world. Using farmlandas an example, we argue that conservation interventions should be implementedwithin a multiscale framework of guiding ecological principles. Inthis context, findings from multilevel governance research can inform a nuancedunderstanding of the role of evidence in conservation governance anddecision-making. We propose that principles of evidence-based conservationcan be used to refine guiding ecological principles across scales, thereby creatinga comprehensive evidence base that underpins decision-making. Thisevolving evidence base, in turn, should be operationalized by considering thefit of ecologically relevant scales to governance levels, paying explicit attentionto issues such as democratic legitimacy and interplay with existing governancestructures. We outline two specific steps for meeting this challenge. Drawingon a strategic combination of conservation interventions, guiding ecologicalprinciples, and insights from multilevel governance research promises to improveboth the effectiveness and legitimacy of conservation action.
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| 10. |
- Hanson, Helena I., et al.
(författare)
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Agricultural land use affects abundance and dispersal tendency of predatory arthropods
- 2017
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Ingår i: Basic and Applied Ecology. - : Elsevier BV. - 1439-1791. ; 18, s. 40-49
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Tidskriftsartikel (refereegranskat)abstract
- Predatory arthropods contribute to biological control, but to become an integral part of agricultural management, it is essential to identify drivers of their spatio-temporal distribution at the landscape scale. This study focuses on how agricultural land use affects the community composition, emergence and dispersal tendency of predatory arthropods. The arthropods were collected in emergence traps during the growing season (14 weeks) in a gradient of agricultural land uses from intensively managed sugar beet fields, over winter wheat fields, to less intensively managed grasslands. The emergence traps were equipped with one pitfall trap and a collecting bottle at the top. The distribution of the arthropods between these two collecting methods was assumed to represent their tendency to move out of the habitat. The grasslands had the highest numbers of spiders, while the winter wheat fields had the highest numbers of omnivorous rove beetles and macropterous predaceous ground beetles. The phenology of emergence differed between the land-use types, resulting in seasonal differences in community composition. The overall dispersal tendency of predatory arthropods was higher in crop fields than in grasslands. This study suggests that only a diverse mix of agricultural land uses will provide high levels of predators from different functional groups, throughout the growing season.
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