| 1. |
- Adman, Per, et al.
(author)
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171 forskare: ”Vi vuxna bör också klimatprotestera”
- 2019
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In: Dagens nyheter (DN debatt). - Stockholm. - 1101-2447.
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Journal article (pop. science, debate, etc.)abstract
- DN DEBATT 26/9. Vuxna bör följa uppmaningen från ungdomarna i Fridays for future-rörelsen och protestera eftersom det politiska ledarskapet är otillräckligt. Omfattande och långvariga påtryckningar från hela samhället behövs för att få de politiskt ansvariga att utöva det ledarskap som klimatkrisen kräver, skriver 171 forskare i samhällsvetenskap och humaniora.
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| 2. |
- Agenäs, Sigrid, et al.
(author)
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Gårdar anses för små – men gör stor nytta
- 2020
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In: Svenska Dagbladet Debatt. - 1101-2412.
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Journal article (pop. science, debate, etc.)abstract
- De små gårdarna är allvarligt hotade och därmed också mosaiklandskapet och den gastronomiska mångfalden. Det skriver flera debattörer.
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| 3. |
- Alejandre, Elizabeth M., et al.
(author)
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Characterization Factors to Assess Land Use Impacts on Pollinator Abundance in Life Cycle Assessment
- 2023
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In: Environmental Science and Technology. - : American Chemical Society (ACS). - 0013-936X .- 1520-5851. ; 57:8, s. 3445-3454
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Journal article (peer-reviewed)abstract
- While wild pollinators play a key role in global food production, their assessment is currently missing from the most commonly used environmental impact assessment method, Life Cycle Assessment (LCA). This is mainly due to constraints in data availability and compatibility with LCA inventories. To target this gap, relative pollinator abundance estimates were obtained with the use of a Delphi assessment, during which 25 experts, covering 16 nationalities and 45 countries of expertise, provided scores for low, typical, and high expected abundance associated with 24 land use categories. Based on these estimates, this study presents a set of globally generic characterization factors (CFs) that allows translating land use into relative impacts to wild pollinator abundance. The associated uncertainty of the CFs is presented along with an illustrative case to demonstrate the applicability in LCA studies. The CFs based on estimates that reached consensus during the Delphi assessment are recommended as readily applicable and allow key differences among land use types to be distinguished. The resulting CFs are proposed as the first step for incorporating pollinator impacts in LCA studies, exemplifying the use of expert elicitation methods as a useful tool to fill data gaps that constrain the characterization of key environmental impacts.
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| 4. |
- Alexandridis, Nikolaos, et al.
(author)
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Archetype models upscale understanding of natural pest control response to land-use change
- 2022
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In: Ecological Applications. - : Wiley. - 1051-0761 .- 1939-5582. ; 32:8
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Journal article (peer-reviewed)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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| 5. |
- Alexandridis, Nikolaos, et al.
(author)
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Carving paths of sustainable intensification for smallholder farming in sub-Saharan Africa
- 2022
-
Conference paper (other academic/artistic)abstract
- Push-pull technology (PPT) is a strategy for controlling agricultural pests, improving soil fertility, diversifying farm output, and reducing gender and age disparities. The benefits of PPT have been demonstrated in East Africa, but efforts to upscale its adoption can face many challenges. Agroecosystems comprise social-ecological networks, with interactions that transcend spatial and temporal scales. These interactions form feedback loops that drive system dynamics, often towards counter-intuitive responses to policy or environmental change. Predicting and managing the behavior of such complex systems typically requires advanced mathematical formulations and precise knowledge, which are often not available for smallholder farming in sub-Saharan Africa. Imprecise indigenous information is in many cases ignored, and predictive social-ecological modelling is limited. We suggest the combined use of causal loop diagrams (CLDs) and qualitative mathematical models (QMMs) for analyzing social-ecological networks involved in upscaling PPT adoption in East Africa. Use of these intuitive tools as boundary objects in participatory model development facilitates exploitation of imprecise knowledge, and increases stakeholder engagement in policy formulation. The distinct characteristics of CLDs and QMMs allow independent representation of the dynamics of PPT adoption by households, landscape-scale control of crop pests and regional economics, as well as cross-scale interactions among these sub-systems. Analysis of system-wide feedback loops can identify leverage points and reduce policy resistance for sustainable intensification pathways, based on upscaling PPT adoption in East Africa.
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| 6. |
- Alexandridis, Nikolaos, et al.
(author)
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Climate change and ecological intensification of agriculture in sub-Saharan Africa : A systems approach to predict maize yield under push-pull technology
- 2023
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In: Agriculture, Ecosystems and Environment. - 0167-8809 .- 1873-2305. ; 352
-
Journal article (peer-reviewed)abstract
- Assessing effects of climate change on agricultural systems and the potential for ecological intensification to increase food security in developing countries is essential to guide management, policy-making and future research. ‘Push-pull’ technology (PPT) is a poly-cropping design developed in eastern Africa that utilizes plant chemicals to mediate plant–insect interactions. PPT application yields significant increases in crop productivity, by reducing pest load and damage caused by arthropods and parasitic weeds, while also bolstering soil fertility. As climate change effects may be species- and/or context-specific, there is need to elucidate how, in interaction with biotic factors, projected climate conditions are likely to influence future functioning of PPT. Here, we first reviewed how changes in temperature, precipitation and atmospheric CO2 concentration can influence PPT components (i.e., land use, soils, crops, weeds, diseases, pests and their natural enemies) across sub-Saharan Africa (SSA). We then imposed these anticipated responses on a landscape-scale qualitative mathematical model of maize production under PPT in eastern Africa, to predict cumulative, structure-mediated impacts of climate change on maize yield. Our review suggests variable impacts of climate change on PPT components in SSA by the end of the 21st century, including reduced soil fertility, increased weed and arthropod pest pressure and increased prevalence of crop diseases, but also increased biological control by pests’ natural enemies. Extrapolating empirical evidence of climate effects to predict responses to projected climate conditions is mainly limited by a lack of mechanistic understanding regarding single and interactive effects of climate variables on PPT components. Model predictions of maize yield responses to anticipated impacts of climate change in eastern Africa suggest predominantly negative future trends. Nevertheless, maize yields can be sustained or increased by favourable changes in system components with less certain future behaviour, including higher PPT adoption, preservation of field edge density and agricultural diversification beyond cereal crops.
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| 7. |
- Alexandridis, Nikolaos, et al.
(author)
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Climate change and ecological intensification of agriculture in sub-Saharan Africa – A systems approach to predict maize yield under push-pull technology
- 2023
-
In: Agriculture, Ecosystems & Environment. - 0167-8809 .- 1873-2305. ; 352
-
Journal article (peer-reviewed)abstract
- Assessing effects of climate change on agricultural systems and the potential for ecological intensification to increase food security in developing countries is essential to guide management, policy-making and future research. ‘Push-pull’ technology (PPT) is a poly-cropping design developed in eastern Africa that utilizes plant chemicals to mediate plant–insect interactions. PPT application yields significant increases in crop productivity, by reducing pest load and damage caused by arthropods and parasitic weeds, while also bolstering soil fertility. As climate change effects may be species- and/or context-specific, there is need to elucidate how, in interaction with biotic factors, projected climate conditions are likely to influence future functioning of PPT. Here, we first reviewed how changes in temperature, precipitation and atmospheric CO2 concentration can influence PPT components (i.e., land use, soils, crops, weeds, diseases, pests and their natural enemies) across sub-Saharan Africa (SSA). We then imposed these anticipated responses on a landscape-scale qualitative mathematical model of maize production under PPT in eastern Africa, to predict cumulative, structure-mediated impacts of climate change on maize yield. Our review suggests variable impacts of climate change on PPT components in SSA by the end of the 21st century, including reduced soil fertility, increased weed and arthropod pest pressure and increased prevalence of crop diseases, but also increased biological control by pests’ natural enemies. Extrapolating empirical evidence of climate effects to predict responses to projected climate conditions is mainly limited by a lack of mechanistic understanding regarding single and interactive effects of climate variables on PPT components. Model predictions of maize yield responses to anticipated impacts of climate change in eastern Africa suggest predominantly negative future trends. Nevertheless, maize yields can be sustained or increased by favourable changes in system components with less certain future behaviour, including higher PPT adoption, preservation of field edge density and agricultural diversification beyond cereal crops.
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| 8. |
- Alexandridis, Nikolaos, et al.
(author)
-
Modelling natural pest control across the world’s agroecosystems – an archetype approach
- 2023
-
Conference paper (other academic/artistic)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 agroecologies. 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 prediction. We propose instead to harness the joint benefits of empirical, theoretical and methodological knowledge for natural pest control modelling across systems by combining trait-mediated understanding from correlative studies with the explicit representation of causal relationships achieved by mechanistic modelling. 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 behaviour in a context-specific 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 archetype models based on general ecological theory and knowledge of American and African agroecosystems explain responses of natural pest control to changes in landscape composition and configuration across Europe. Analysing global datasets on drivers and components of natural pest control and mechanistic models of the resulting archetypes can resolve inconsistent responses to land-use change, and improve prediction of natural pest control potential, as well as synergies and trade-offs with other ecosystem services.
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| 9. |
- Alexandridis, Nikolaos, et al.
(author)
-
Models of natural pest control : Towards predictions across agricultural landscapes
- 2021
-
In: Biological Control. - : Elsevier BV. - 1049-9644. ; 163
-
Research review (peer-reviewed)abstract
- Natural control of invertebrate crop pests has the potential to complement or replace conventional insecticide-based practices, but its mainstream application is hampered by predictive unreliability across agroecosystems. Inconsistent responses of natural pest control to changes in landscape characteristics have been attributed to ecological complexity and system-specific conditions. Here, we review agroecological models and their potential to provide predictions of natural pest control across agricultural landscapes. Existing models have used a multitude of techniques to represent specific crop-pest-enemy systems at various spatiotemporal scales, but less wealthy regions of the world are underrepresented. A realistic representation of natural pest control across systems appears to be hindered by a practical trade-off between generality and realism. Nonetheless, observations of context-sensitive, trait-mediated responses of natural pest control to land-use gradients indicate the potential of ecological models that explicitly represent the underlying mechanisms. We conclude that modelling natural pest control across agroecosystems should exploit existing mechanistic techniques towards a framework of contextually bound generalizations. Observed similarities in causal relationships can inform the functional grouping of diverse agroecosystems worldwide and the development of the respective models based on general, but context-sensitive, ecological mechanisms. The combined use of qualitative and quantitative techniques should allow the flexible integration of empirical evidence and ecological theory for robust predictions of natural pest control across a wide range of agroecological contexts and levels of knowledge availability. We highlight challenges and promising directions towards developing such a general modelling framework.
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| 10. |
- Alignier, Audrey, et al.
(author)
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Configurational crop heterogeneity increases within-field plant diversity
- 2020
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In: Journal of Applied Ecology. - : Wiley. - 0021-8901 .- 1365-2664. ; 57:4, s. 654-663
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Journal article (peer-reviewed)abstract
- Increasing landscape heterogeneity by restoring semi-natural elements to reverse farmland biodiversity declines is not always economically feasible or acceptable to farmers due to competition for land. We hypothesized that increasing the heterogeneity of the crop mosaic itself, hereafter referred to as crop heterogeneity, can have beneficial effects on within-field plant diversity. Using a unique multi-country dataset from a cross-continent collaborative project covering 1,451 agricultural fields within 432 landscapes in Europe and Canada, we assessed the relative effects of compositional and configurational crop heterogeneity on within-field plant diversity components. We also examined how these relationships were modulated by the position within the field. We found strong positive effects of configurational crop heterogeneity on within-field plant alpha and gamma diversity in field interiors. These effects were as high as the effect of semi-natural cover. In field borders, effects of crop heterogeneity were limited to alpha diversity. We suggest that a heterogeneous crop mosaic may overcome the high negative impact of management practices on plant diversity in field interiors, whereas in field borders, where plant diversity is already high, landscape effects are more limited. Synthesis and applications. Our study shows that increasing configurational crop heterogeneity is beneficial to within-field plant diversity. It opens up a new effective and complementary way to promote farmland biodiversity without taking land out of agricultural production. We therefore recommend adopting manipulation of crop heterogeneity as a specific, effective management option in future policy measures, perhaps adding to agri-environment schemes, to contribute to the conservation of farmland plant diversity.
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| 11. |
- Andersson, Georg K.S., et al.
(author)
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Landscape-scale diversity of plants, bumblebees and butterflies in mixed farm-forest landscapes of Northern Europe : Clear-cuts do not compensate for the negative effects of plantation forest cover
- 2022
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In: Biological Conservation. - : Elsevier BV. - 0006-3207. ; 274
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Journal article (peer-reviewed)abstract
- To assess the biodiversity consequences of contemporary land-use trends in Northern Europe, where agriculture is being replaced by forestry, we need a better knowledge of the contributions of constituting habitats to biodiversity. Here, we use purposefully collected data from 87 sites to model how agricultural habitats, including semi-natural pastures, sown temporary grassland (leys), cereal crops, and forest habitats comprising both mature production forests and clear-cuts, contribute to landscape-scale diversity of plants, bumblebees and butterflies in boreonemoral Sweden. At the local scale, species richness was highest in semi-natural pastures, intermediate in cereal crops and leys and lowest in forest. In clear-cuts, species richness was similarly high to that in semi-natural pastures. Countryside species-area models show that at a landscape scale, the high local richness in clear-cuts was more than offset by the low species richness encountered in forest. At landscape scale, semi-natural pastures, and in the case of plants also cereal crops, were major contributors of unique species. Leys and semi-natural pastures were both important contributors to bumblebee diversity. The effect of the surrounding landscape composition on local diversity was weak, suggesting that area-based approximations of landscape-scale species richness were reasonable. We conclude that clear-cuts constitute habitats for open-land species but cannot maintain landscape-scale diversity in the face of agricultural abandonment when open land is replaced by even-aged production forests. Maintaining farmland, in particular semi-natural pastures but also cereals and leys, is therefore critical to maintaining the landscape-scale species richness of plants and insects in forestry-dominated areas.
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| 12. |
- Baey, Charlotte, et al.
(author)
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A model to account for data dependency when estimating floral cover in different land use types over a season
- 2017
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In: Environmental and Ecological Statistics. - : Springer Science and Business Media LLC. - 1352-8505 .- 1573-3009. ; 24:4, s. 505-527
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Journal article (peer-reviewed)abstract
- We propose a model to consider data dependencies and assess spatial and temporal variability in land use specific floral coverage across landscapes. Data dependence arising from repeated measurements across the flowering season is taken into account using hierarchical Archimedean copulas, where the correlation is assumed to be stronger within seasonal periods than between periods. For each seasonal period, a bounded probability distribution is assigned to capture spatial variability in floral cover. The model uses a Bayesian approach and can assess land-use-specific floral covers by integrating experts judgments and field data. The model is applied to assess floral covers in four land use types in southern Sweden, where seasonal variability is captured by dividing the season into two periods according to winter oilseed rape flowering. Floral cover is updated using Markov Chain Monte Carlo sampling based on data from 16 landscapes and 2 years, with repeated measures available from each of the two seasonal periods. Our results indicate that considering data dependence improved the estimation of floral cover based on data observed during a season. Different copula families specifying multivariate probability distributions were tested, and no family had a consistently higher performance in the four tested land use types. Uncertainty in both mode and variability of floral cover was higher when data dependence were accounted for. Posterior modes of floral covers in semi-natural grassland were higher than in field edges, but both expert’s best guesses were higher than these estimates. This confirms previous findings in expert elicitation processes that experts may fail to discriminate extreme values on a bounded range. Floral cover in flower strips were estimated to be smaller/higher than semi-natural grasslands early/late in the season. The mode of floral cover in oil seed rape was estimated to be close to 100%, and higher than estimates provided by expert judgment. Floral covers for different land use classes are key parameters when quantifying floral resources at a landscape level whose assessments rely on both expert judgment and field measurements.
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| 13. |
- Baey, Charlotte, et al.
(author)
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Calibration of a bumble bee foraging model using Approximate Bayesian Computation
- 2023
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In: Ecological Modelling. - : Elsevier BV. - 0304-3800. ; 477
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Journal article (peer-reviewed)abstract
- 1. Challenging calibration of complex models can be approached by using prior knowledge on the parameters. However, the natural choice of Bayesian inference can be computationally heavy when relying on Markov Chain Monte Carlo (MCMC) sampling. When the likelihood of the data is intractable, alternative Bayesian methods have been proposed. Approximate Bayesian Computation (ABC) only requires sampling from the data generative model, but may be problematic when the dimension of the data is high. 2. We studied alternative strategies to handle high dimensional data in ABC applied to the calibration of a spatially explicit foraging model for Bombus terrestris. The first step consisted in building a set of summary statistics carrying enough biological meaning, i.e. as much as the original data, and then applying ABC on this set. Two ABC strategies, the use of regression adjustment leading to the production of ABC posterior samples, and the use of machine learning approaches to approximate ABC posterior quantiles, were compared with respect to coverage of model estimates and true parameter values. The comparison was made on simulated data as well as on data from two field studies. 3. Results from simulated data showed that some model parameters were easier to calibrate than others. Approaches based on random forests in general performed better on simulated data. They also performed well on field data, even though the posterior predictive distribution exhibited a higher variance. Nonlinear regression adjustment performed better than linear ones, and the classical ABC rejection algorithm performed badly. 4. ABC is an interesting and appealing approach for the calibration of complex models in biology, such as spatially explicit foraging models. However, while ABC methods are easy to implement, they often require considerable tuning.
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| 14. |
- Barnes, Andrew D., et al.
(author)
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Direct and cascading impacts of tropical land-use change on multi-trophic biodiversity
- 2017
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In: Nature Ecology and Evolution. - : Springer Science and Business Media LLC. - 2397-334X. ; 1:10, s. 1511-1519
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Journal article (peer-reviewed)abstract
- The conversion of tropical rainforest to agricultural systems such as oil palm alters biodiversity across a large range of interacting taxa and trophic levels. Yet, it remains unclear how direct and cascading effects of land-use change simultaneously drive ecological shifts. Combining data from a multi-taxon research initiative in Sumatra, Indonesia, we show that direct and cascading land-use effects alter biomass and species richness of taxa across trophic levels ranging from microorganisms to birds. Tropical land use resulted in increases in biomass and species richness via bottom-up cascading effects, but reductions via direct effects. When considering direct and cascading effects together, land use was found to reduce biomass and species richness, with increasing magnitude at higher trophic levels. Our analyses disentangle the multifaceted effects of land-use change on tropical ecosystems, revealing that biotic interactions on broad taxonomic scales influence the ecological outcome of anthropogenic perturbations to natural ecosystems.
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| 15. |
- Blasi, Maria, et al.
(author)
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A model of wild bee populations accounting for spatial heterogeneity and climate-induced temporal variability of food resources at the landscape level
- 2022
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In: Ecology and Evolution. - : Wiley. - 2045-7758. ; 12:6
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Journal article (peer-reviewed)abstract
- The viability of wild bee populations and the pollination services that they provide are driven by the availability of food resources during their activity period and within the surroundings of their nesting sites. Changes in climate and land use influence the availability of these resources and are major threats to declining bee populations. Because wild bees may be vulnerable to interactions between these threats, spatially explicit models of population dynamics that capture how bee populations jointly respond to land use at a landscape scale and weather are needed. Here, we developed a spatially and temporally explicit theoretical model of wild bee populations aiming for a middle ground between the existing mapping of visitation rates using foraging equations and more refined agent-based modeling. The model is developed for Bombus sp. and captures within-season colony dynamics. The model describes mechanistically foraging at the colony level and temporal population dynamics for an average colony at the landscape level. Stages in population dynamics are temperature-dependent triggered by a theoretical generalized seasonal progression, which can be informed by growing degree days. The purpose of the LandscapePhenoBee model is to evaluate the impact of system changes and within-season variability in resources on bee population sizes and crop visitation rates. In a simulation study, we used the model to evaluate the impact of the shortage of food resources in the landscape arising from extreme drought events in different types of landscapes (ranging from different proportions of semi-natural habitats and early and late flowering crops) on bumblebee populations.
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| 16. |
- Blasi, Maria, et al.
(author)
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Evaluating predictive performance of statistical models explaining wild bee abundance in a mass-flowering crop
- 2021
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In: Ecography. - : Wiley. - 0906-7590 .- 1600-0587. ; 44:4, s. 525-536
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Journal article (peer-reviewed)abstract
- Wild bee populations are threatened by current agricultural practices in many parts of the world, which may put pollination services and crop yields at risk. Loss of pollination services can potentially be predicted by models that link bee abundances with landscape-scale land-use, but there is little knowledge on the degree to which these statistical models are transferable across time and space. This study assesses the transferability of models for wild bee abundance in a mass-flowering crop across space (from one region to another) and across time (from one year to another). The models used existing data on bumblebee and solitary bee abundance in winter oilseed rape fields, together with high-resolution land-use crop-cover and semi-natural habitats data, from studies conducted in five different regions located in four countries (Sweden, Germany, Netherlands and the UK), in three different years (2011, 2012, 2013). We developed a hierarchical model combining all studies and evaluated the transferability using cross-validation. We found that both the landscape-scale cover of mass-flowering crops and permanent semi-natural habitats, including grasslands and forests, are important drivers of wild bee abundance in all regions. However, while the negative effect of increasing mass-flowering crops on the density of the pollinators is consistent between studies, the direction of the effect of semi-natural habitat is variable between studies. The transferability of these statistical models is limited, especially across regions, but also across time. Our study demonstrates the limits of using statistical models in conjunction with widely available land-use crop-cover classes for extrapolating pollinator density across years and regions, likely in part because input variables such as cover of semi-natural habitats poorly capture variability in pollinator resources between regions and years.
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| 17. |
- Boke Olén, Niklas, et al.
(author)
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Effects of farm type on food production, landscape openness, grassland biodiversity, and greenhouse gas emissions in mixed agricultural-forestry regions
- 2021
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In: Agricultural Systems. - : Elsevier BV. - 0308-521X .- 1873-2267. ; 189
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Journal article (peer-reviewed)abstract
- Context: The global demand for food is expected to continue increasing for decades, which may drive both agricultural expansion and intensification. The associated environmental impacts are potentially considerable but will depend on how the agricultural sector develops. Currently, there are contrasting regional developments in agriculture; expansion and/or intensification in some regions and abandonment in others, as well as changes in the type of farming. However, the environmental consequences of changes in farm type are not well understood. Objective: We have evaluated the impacts of farm type on food production and three key environmental variables—landscape openness, grassland biodiversity and greenhouse gas (GHG) emissions—in three marginal agricultural regions in Sweden. Methods: We do this by first dividing the population of farms in each region into types, based on their land-use and livestock holdings using an innovative clustering method. Thereafter we analysed changes in production activities for farm types over time and evaluated the environmental and food-production impacts, where landscape openness is quantified using a novel indicator. Results and conclusion: Our results show that there is not one single farm type that would simultaneously maximize food production, grassland biodiversity, and landscape openness, whilst minimizing GHG emissions. However, there exists considerable potential to manage the trade-offs between food production and these environmental variables. For example, by reducing land use for dairying and instead increasing both cropping for food production and extensive livestock grazing to maintain landscape openness and biodiversity-rich semi-natural pastures, it would keep food production at similar levels. Significance: Our farm typology allows us to assess the multifunctionality of farming, by relating contrasting production activities to multiple ecosystem services, grassland biodiversity and GHG emissions for informing policy towards more sustainable agriculture. We have demonstrated this with examples under Swedish conditions, but it should to a large extent also be applicable for other countries.
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| 18. |
- Bosem Baillod, Aliette, et al.
(author)
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Landscape-scale interactions of spatial and temporal cropland heterogeneity drive biological control of cereal aphids
- 2017
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In: Journal of Applied Ecology. - : Wiley. - 0021-8901. ; 54:6, s. 1804-1813
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Journal article (peer-reviewed)abstract
- Agricultural landscapes are characterised by dynamic crop mosaics changing in composition and configuration over space and time. Although semi-natural habitat has been often shown to contribute to pest biological control, the effects of increasing landscape heterogeneity with cropland have been disregarded. Here, we examine how cereal aphids, their enemies and biological control are affected by the composition and configuration of the crop mosaic and its inter-annual change due to crop rotation. We studied the abundance of cereal aphids, natural enemies and aphid parasitism over 2 years on 51 winter wheat fields. Arthropods were monitored at three distances (0, 10, 30 m) from field borders. Fields were embedded in landscapes of 1-km diameter selected along orthogonal gradients of compositional crop heterogeneity (crop diversity), configurational heterogeneity (field border and grassy field boundary length) and inter-annual change in cover of aphid host habitats (cereal, maize and grassland). We aimed to disentangle spatial and temporal heterogeneity effects through these independent landscape gradients. Aphid densities were lower in landscapes with smaller field size (more field borders) coupled with high amounts of grassy field boundaries. Aphid densities decreased also in landscapes with higher crop diversity when the cover of aphid host habitat had decreased from the year before. Aphid natural enemy densities decreased with smaller field size and high amounts of grassy field boundaries. Aphid parasitism decreased with the inter-annual expansion in aphid host habitat, but only in landscapes with small field sizes. Synthesis and applications. Our study shows for the first time that cereal aphid numbers can be reduced by optimising the composition, configuration and temporal heterogeneity of the crop mosaic. We highlight the value of maintaining small field sizes in agricultural landscapes and high densities of grassy boundaries for reducing aphid abundance. Landscape-wide crop diversification can reduce aphid densities as well.
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| 19. |
- 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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| 20. |
- Clough, Yann, et al.
(author)
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Field sizes and the future of farmland biodiversity in European landscapes
- 2020
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In: Conservation Letters. - : Wiley. - 1755-263X. ; 13:6
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Research review (peer-reviewed)abstract
- Lower diversity of plant and animal farmland species are usually reported where cropland has been aggregated into larger fields, which raises prospects of curbing declines in European farmland biodiversity and associated ecosystem services by halting trends to field size increases associated to agricultural intensification, without having to set aside arable land for conservation. Here, we consider the factors underlying trade-offs between farmer income and biodiversity as mediated by field size at local and landscape scales, and how these trade-offs may be overcome. Field sizes are still increasing, facilitated by increasing farm sizes and land consolidation. Decreases in working time and fuel expenses when fields are larger, uptake of larger machinery and subsidies favoring larger farms provide incentives to manage land in larger units, putting farmland biodiversity further at risk. Yet, field size-mediated ecological–economic trade-offs are largely ignored in policy and research. We recommend internalizing the ecological effects of changes in landscape-scale field size into land consolidation scheme design, ensuring that EU Common Agricultural Policy post-2020 rewards farmers that maintain and recreate fine-grained landscapes where these are essential for farmland biodiversity targets, and reducing economic–ecological trade-offs by stimulating agricultural research and innovation for economically efficient yet biodiversity-friendly farming in fine-grained landscapes.
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| 21. |
- Clough, Yann, et al.
(author)
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Land-use choices follow profitability at the expense of ecological functions in Indonesian smallholder landscapes
- 2016
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In: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 7
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Journal article (peer-reviewed)abstract
- Smallholder-dominated agricultural mosaic landscapes are highlighted as model production systems that deliver both economic and ecological goods in tropical agricultural landscapes, but trade-offs underlying current land-use dynamics are poorly known. Here, using the most comprehensive quantification of land-use change and associated bundles of ecosystem functions, services and economic benefits to date, we show that Indonesian smallholders predominantly choose farm portfolios with high economic productivity but low ecological value. The more profitable oil palm and rubber monocultures replace forests and agroforests critical for maintaining above- and below-ground ecological functions and the diversity of most taxa. Between the monocultures, the higher economic performance of oil palm over rubber comes with the reliance on fertilizer inputs and with increased nutrient leaching losses. Strategies to achieve an ecological-economic balance and a sustainable management of tropical smallholder landscapes must be prioritized to avoid further environmental degradation.
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| 22. |
- Clough, Yann, et al.
(author)
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Services and disservices of ant communities in tropical cacao and coffee agroforestry systems
- 2017
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In: Ant-Plant Interactions : Impacts of Humans on Terrestrial Ecosystems - Impacts of Humans on Terrestrial Ecosystems. - : Cambridge University Press. - 9781107159754 - 9781316671825 ; , s. 333-355
-
Book chapter (peer-reviewed)abstract
- Tropical tree crops such as cacao and coffee are produced around the tropics in diverse, multistrata agroforests as well as monoculture plantations Box 16.1 and references therein). The smallholders cultivating these systems battle pests and diseases that differ regionally and change over time, but often take a significant part of their yield, and therefore their revenue. In these perennial systems, ants are tremendously diverse and abundant, and affect pests and diseases directly as well as indirectly. Management by farmers of particular ant species to control insect pests has a long history (Offenberg, 2015). It is not until recently that the effects of ants on yields have been quantified. The complex interactions through which ants affect the crop plants, and how their mediation by species- and community-level characteristics, are starting to be better understood. The extent of the impact ants have on yields and revenue justifies the anthropocentric framing of the outcome of these interactions in terms of ecosystem services and disservices. In this chapter we present the current state of knowledge on agroforest ant communities, economically relevant ecological interactions driven by these communities and the way landscape-scale land-use change and climate change can be expected to influence ants and ant effects on insect communities and yields. Finally, we discuss how farmers may adapt their management to support ant-mediated ecosystem services and minimize potential disservices. We refer to Del Toro et al. (2012) and Choate and Drummond (2011) for more broad reviews of the role of ants in agriculture, as providers of biological control and other ecosystem services and disservices. Taxonomically and Functionally Rich Ant Communities. Ant surveys from cacao and coffee systems from throughout the range of these crops show a very high species richness that in most cases is comparable to that found in undisturbed forests (Table 16.1). Agroforests harbor arboreal and ground-dwelling ants. This includes species that nest in the canopy and trunk of the trees (dead wood, hollow twigs, foliage, sometimes with carton/silk/dirt nesting structures), in the herb layer, in the litter layer, on open ground, in epiphytic and parasitic plants, dead wood debris and other plant residues, such as dry cacao pods on the ground or on the tree (Room, 1971; De la Mora et al., 2013; Castaño-Meneses et al., 2015).
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| 23. |
- Denmead, Lisa H., et al.
(author)
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The role of ants, birds and bats for ecosystem functions and yield in oil palm plantations
- 2017
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In: Ecology. - : Wiley. - 0012-9658 .- 1939-9170. ; 98:7, s. 1945-1956
-
Journal article (peer-reviewed)abstract
- One of the world's most important and rapidly expanding crops, oil palm, is associated with low levels of biodiversity. Changes in predator communities might alter ecosystem services and subsequently sustainable management but these links have received little attention to date. Here, for the first time, we manipulated ant and flying vertebrate (birds and bats) access to oil palms in six smallholder plantations in Sumatra (Indonesia) and measured effects on arthropod communities, related ecosystem functions (herbivory, predation, decomposition and pollination) and crop yield. Arthropod predators increased in response to reductions in ant and bird access, but the overall effect of experimental manipulations on ecosystem functions was minimal. Similarly, effects on yield were not significant. We conclude that ecosystem functions and productivity in oil palm are, under current levels of low pest pressure and large pollinator populations, robust to large reductions of major predators.
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| 24. |
- Drescher, Jochen, et al.
(author)
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Ecological and socio-economic functions across tropical land use systems after rainforest conversion
- 2016
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In: Philosophical Transactions of the Royal Society B: Biological Sciences. - : The Royal Society. - 0962-8436 .- 1471-2970. ; 371:1694
-
Journal article (peer-reviewed)abstract
- Tropical lowland rainforests are increasingly threatened by the expansion of agriculture and the extraction of natural resources. In Jambi Province, Indonesia, the interdisciplinary EFForTS project focuses on the ecological and socio-economic dimensions of rainforest conversion to jungle rubber agroforests and monoculture plantations of rubber and oil palm. Our data confirm that rainforest transformation and land use intensification lead to substantial losses in biodiversity and related ecosystem functions, such as decreased above-and below-ground carbon stocks. Owing to rapid step-wise transformation from forests to agroforests to monoculture plantations and renewal of each plantation type every few decades, the converted land use systems are continuously dynamic, thus hampering the adaptation of animal and plant communities. On the other hand, agricultural rainforest transformation systems provide increased income and access to education, especially for migrant smallholders. Jungle rubber and rubber monocultures are associated with higher financial land productivity but lower financial labour productivity compared to oil palm, which influences crop choice: smallholders that are labour-scarce would prefer oil palm while land-scarce smallholders would prefer rubber. Collecting long-term data in an interdisciplinary context enables us to provide decision-makers and stakeholders with scientific insights to facilitate the reconciliation between economic interests and ecological sustainability in tropical agricultural landscapes.
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| 25. |
- Droste, Nils, et al.
(author)
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Soil carbon insures arable crop production against increasing adverse weather due to climate change
- 2020
-
In: Environmental Research Letters. - : IOP Publishing. - 1748-9326. ; 15:12
-
Journal article (peer-reviewed)abstract
- Intensification of arable crop production degrades soil health and production potential through loss of soil organic carbon. This, potentially, reduces agriculture's resilience to climate change and thus food security. Furthermore, the expected increase in frequency of adverse and extreme weather events due to climate change are likely to affect crop yields differently, depending on when in the growing season they occur. We show that soil carbon provides farmers with a natural insurance against climate change through a gain in yield stability and more resilient production. To do this, we combined yield observations from 12 sites and 54 years of Swedish long-term agricultural experiments with historical weather data. To account for heterogenous climate effects, we partitioned the growing season into four representative phases for two major cereal crops. Thereby, we provide evidence that higher soil carbon increases yield gains from favourable conditions and reduces yield losses due to adverse weather events and how this occurs over different stages of the growing season. However, agricultural management practices that restore the soil carbon stock, thus contributing to climate change mitigation and adaptation, usually come at the cost of foregone yield for the farmer in the short term. To halt soil degradation and make arable crop production more resilient to climate change, we need agricultural policies that address the public benefits of soil conservation and restoration.
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| 26. |
- Dänhardt, Juliana, et al.
(author)
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Collective Implementation of Ecological Focus Areas : Evaluation of the effects on ecosystem services, agriculture and administration
- 2018
-
Reports (other academic/artistic)abstract
- Ecosystem services are fundamental to the welfare of mankind, yet these services are often invisible in many social decisions. This report evaluates the effects on the ecosystem services pollination and biological pest control if Sweden were to introduce collective implementation of EFAs as part of the single payment scheme, including quality improvement measures such as establishing flowering plants.The potential environmental effects are seen in relation to the impacts on the economies of farmers and their acceptance of collective implementation, as well as the administrative costs for the authorities. This study is a step towards integrating the value of ecosystem services into decisions in society, something that is to be achieved by 2018 under the milestone targets in Sweden's environmental objectives system.The study that formed the basis of this report was carried out by the Centre for Environmental and Climate Research at Lund University. The work was carried out within the government commission Environmental effects of the CAP. The Swedish Environmental Protection Agency is the primary authority responsible for this report. The Swedish Board of Agriculture, the Swedish National Heritage Board, the Swedish Agency for Marine and Water Management and the County administrative boards also participated in this project.
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| 27. |
- Dänhardt, Juliana, et al.
(author)
-
Ekologiska fokusarealer i samverkan : Utvärdering av effekter på ekosystemtjänster, jordbruk och administration
- 2017
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Reports (other academic/artistic)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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| 28. |
- Ekström, Hanna, et al.
(author)
-
Barking up the wrong tree? : A guide to forest owner typology methods
- 2024
-
In: Forest Policy and Economics. - : Elsevier. - 1389-9341 .- 1872-7050. ; 163
-
Journal article (peer-reviewed)abstract
- Creating typologies of forest owners is a common approach for analyzing and understanding heterogeneity in responses to forest policies and management practice uptake. While many forest owner typologies have been developed, only a few quantitative methods dominate the field with little information on how methodological choice affects outcomes. In this study we compare five methods for quantitative typology formation and ask what type of information each method provides, and to which degree the methods complement each other. Empirically we use data from a survey conducted in 2014–2015 about Swedish forest owner's objectives, attitudes, and factors of decision-making. The results show that individual forest owners are assigned to different clusters by the compared methods, and how each method highlights different aspects of forest owner characteristics. The study shows the importance of method selection as it influences how we can describe and interpret forest owners in connection to policy adoption, uptake of practices, and environmental awareness. We conclude by providing basis for a methodological guidance on how to make judgments when selecting method(s) to typology formation based on research purpose and approach.
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| 29. |
- Ekström, Hanna, et al.
(author)
-
Barking up the wrong tree? : A guide to forest owner typology methods
- 2024
-
In: Forest Policy and Economics. - 1389-9341. ; 163
-
Journal article (peer-reviewed)abstract
- Creating typologies of forest owners is a common approach for analyzing and understanding heterogeneity in responses to forest policies and management practice uptake. While many forest owner typologies have been developed, only a few quantitative methods dominate the field with little information on how methodological choice affects outcomes. In this study we compare five methods for quantitative typology formation and ask what type of information each method provides, and to which degree the methods complement each other. Empirically we use data from a survey conducted in 2014–2015 about Swedish forest owner's objectives, attitudes, and factors of decision-making. The results show that individual forest owners are assigned to different clusters by the compared methods, and how each method highlights different aspects of forest owner characteristics. The study shows the importance of method selection as it influences how we can describe and interpret forest owners in connection to policy adoption, uptake of practices, and environmental awareness. We conclude by providing basis for a methodological guidance on how to make judgments when selecting method(s) to typology formation based on research purpose and approach.
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| 30. |
- Ganser, Dominik, et al.
(author)
-
Local and landscape drivers of arthropod diversity and decomposition processes in oil palm leaf axils
- 2017
-
In: Agricultural and Forest Entomology. - : Wiley. - 1461-9555. ; 19:1, s. 60-69
-
Journal article (peer-reviewed)abstract
- Oil palm expansion results in a loss of biodiversity and associated ecosystem services. However, there are factors that influence the severity of these impacts and enhancing biodiversity within plantations is important. In the present study, we examined the role of epiphytes for supporting arthropod communities in oil palm plantations in Sumatra, Indonesia. We considered the effects of landscape context and local characteristics (epiphyte cover, herbicide use and local microclimate) on arthropod communities and litter decomposition in oil palm leaf axils. We surveyed arthropods and measured decomposition rates at two different heights on 80 oil palms located at the centre and edge of eight plantations. We found that oil palms at the edge of plantations hosted a higher abundance and more arthropod taxa than oil palms in the centre of plantations. Moreover, organic matter mass and height of the leaf axil were important for arthropod communities, and the decomposition rate was negatively related to ant abundance. However, epiphyte cover did not influence arthropod communities. The results of the present study show that leaf axils with more organic matter and at a higher location on the oil palm promote arthropod biodiversity. Furthermore, oil palm plantations adjacent to different land-use systems have enhanced biodiversity.
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| 31. |
- Gardner, Emma, et al.
(author)
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Field boundary features can stabilise bee populations and the pollination of mass-flowering crops in rotational systems
- 2021
-
In: Journal of Applied Ecology. - : Wiley. - 0021-8901 .- 1365-2664. ; 58:10, s. 2287-2304
-
Journal article (peer-reviewed)abstract
- Pollinators experience large spatiotemporal fluctuations in resource availability when mass-flowering crops are rotated with resource-poor cereal crops. Yet, few studies have considered the effect this has on pollinator population stability, nor how this might be mitigated to maintain consistent crop pollination services. We assess the potential of boundary features (standard narrow 1 m grassy margins, hedgerows and wide 4 m agri-environment margins) to support and stabilise pollinator populations and pollination service in agricultural landscapes under crop rotation. Assuming a 6-year rotation, we use a process-based pollinator model to predict yearly pollinator population size and in-crop visitation rates to oilseed rape and field bean across 117 study landscapes in England with varying amounts of boundary features. We model both ground-nesting bumblebees and solitary bees and compare the predictions including and excluding boundary features from the landscapes. Ground-nesting bumblebee populations, whose longer-lifetime colonies benefit from continuity of resources, were larger and more stable (relative to the no-features scenario) in landscapes with more boundary features. Ground-nesting solitary bee populations were also larger but not significantly more stable, except with the introduction of wide permanent agri-environment margins, due to their shorter lifetimes and shorter foraging/dispersal ranges. Crop visitation by ground-nesting bumblebees was greater and more stable in landscapes with more boundary features, partly due to increased colony growth prior to crop flowering. Time averaged crop visitation by ground-nesting solitary bees was slightly lower, due to females dividing their foraging time between boundary features and the crop. However, despite this, the minimum pollination service delivered was higher, due to the more stable delivery. Synthesis and applications. Field boundary features have an important role in stabilising pollinator populations and pollination service in rotational systems, although maintenance of larger semi-natural habitat patches may be more effective for stabilising less mobile solitary bee populations. We recommend using combinations of boundary features, accounting for pollinator range when spacing features/rotating crops, and synchronising boundary feature management with crop rotation to maximise their stabilising benefits.
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| 32. |
- Gardner, Emma, et al.
(author)
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Reliably predicting pollinator abundance : Challenges of calibrating process-based ecological models
- 2020
-
In: Methods in Ecology and Evolution. - 2041-210X. ; 11:12, s. 1673-1689
-
Journal article (peer-reviewed)abstract
- Pollination is a key ecosystem service for global agriculture but evidence of pollinator population declines is growing. Reliable spatial modelling of pollinator abundance is essential if we are to identify areas at risk of pollination service deficit and effectively target resources to support pollinator populations. Many models exist which predict pollinator abundance but few have been calibrated against observational data from multiple habitats to ensure their predictions are accurate. We selected the most advanced process-based pollinator abundance model available and calibrated it for bumblebees and solitary bees using survey data collected at 239 sites across Great Britain. We compared three versions of the model: one parameterised using estimates based on expert opinion, one where the parameters are calibrated using a purely data-driven approach and one where we allow the expert opinion estimates to inform the calibration process. All three model versions showed significant agreement with the survey data, demonstrating this model's potential to reliably map pollinator abundance. However, there were significant differences between the nesting/floral attractiveness scores obtained by the two calibration methods and from the original expert opinion scores. Our results highlight a key universal challenge of calibrating spatially explicit, process-based ecological models. Notably, the desire to reliably represent complex ecological processes in finely mapped landscapes necessarily generates a large number of parameters, which are challenging to calibrate with ecological and geographical data that are often noisy, biased, asynchronous and sometimes inaccurate. Purely data-driven calibration can therefore result in unrealistic parameter values, despite appearing to improve model-data agreement over initial expert opinion estimates. We therefore advocate a combined approach where data-driven calibration and expert opinion are integrated into an iterative Delphi-like process, which simultaneously combines model calibration and credibility assessment. This may provide the best opportunity to obtain realistic parameter estimates and reliable model predictions for ecological systems with expert knowledge gaps and patchy ecological data.
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| 33. |
- Gras, Pierre, et al.
(author)
-
How ants, birds and bats affect crop yield along shade gradients in tropical cacao agroforestry
- 2016
-
In: Journal of Applied Ecology. - : Wiley. - 0021-8901. ; , s. 953-963
-
Journal article (peer-reviewed)abstract
- Tropical agroforests are diverse systems where several predator groups shape animal communities and plant-arthropod interactions. Ants, birds and bats in particular can reduce herbivore numbers and thereby increase crop yield. However, the relative importance of these groups, whether they interact, and how this interaction is affected by management and landscape context, is poorly understood. We jointly manipulated access of ants, birds and bats in Indonesian smallholder cacao agroforestry across gradients of shade and distance to natural forest. We quantified arthropod abundance, pest damage and yield. In control treatments, yield was highest under 30-40% canopy cover. Ant exclusion strongly reduced yield (from 600 to 300 kg ha-1 year-1) at 15% canopy cover. Bird exclusion impaired yield (from 400 to 250 kg ha-1 year-1) at 60% and enhanced yield (from 600 to 900 kg ha-1 year-1) at 15% canopy cover, while bats had no effect. Yield increased with forest proximity, a pattern not related to predator access. No interactive effects among predator exclusions on yield, pest damage and arthropod communities were found. Ant exclusion increased numbers of herbivores below 30% canopy cover, without reducing spider abundances. Bird exclusion reduced herbivore and increased spider abundances. Synthesis and applications. Using exclusion studies, we estimated that ants and birds cause cacao yield to vary between 100 and 800 kg ha-1 year-1, depending on shade-tree management. In all but the most shaded agroforests, ants were pivotal in supporting yields. Yields under low-canopy cover were strongly dependent on access by predator groups, with birds reducing rather than increasing yield. Hence, cacao farmers should refrain from disturbing ant communities and maintain 30-40% shade-tree canopy cover not only for ecophysiological reasons but also to buffer variability in predator communities.
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| 34. |
- Haslund, Knut Per, et al.
(author)
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Bra vallersättning och kompensationsstöd? : Hur kan olika utformningar påverka jordbruket, miljön, och samhällsekonomin?
- 2016
-
Reports (other academic/artistic)abstract
- Positiva och negativa miljöeffekterVallersättningen och kompensationsstödet leder båda till att arealen vall och antalet nötkreatur ökar kraftigt. Utredningen konstaterar att effekten av vallodling på biologisk mångfald, både när det gäller sällsynta arter och ekosystemtjänster, är otillräckligt känd. Kompensationsstödet gör det företagsekonomiskt lönsamt att hävda betydligt större areal permanent betesmark, men vallersättningen leder däremot till något lägre betesareal.Det svenska jordbrukets kväve- och fosforläckage har varit lägre under de bådaanalyserade programperioderna tack vare vallersättningen. Under perioden 2015–20 är kväveläckaget är lägre än vad det skulle ha varit utan stödet också i slättbygderna, till skillnad från i landsbygdsprogrammets föregåendeperiod 2007–14. Kompensationsstödet medför tvärtom att växtnäringsläckagetär högre än vad det skulle vara om stödet inte fanns. Användningen av växtskyddsmedel i jordbruket påverkas inte mycket av dessa stöd under perioden 2015–20. Kompensationsstödet har under båda perioderna medfört stora utsläpp av växthusgaser. Vallersättningen är däremot bra ur klimatsynpunkt, om än inte lika starkt under perioden 2015–20 som under den föregående perioden. Stödens klimatpåverkan sker huvudsakligen genom att påverka mängden kol bundet i marken och antalet nötkreatur som avger växthusgasen metan, medan deras inverkan på jordbrukets användning av fossilbränsle till traktorer och annat är liten i sammanhanget. Kompensationsstödet är samhällsekonomiskt olönsamtVallersättningen medförde stora samhällsekonomiska förluster i början av perioden 2007–10, men efter ändrade stödregler och med högre världsmarknadspriser blev den i stället mycket lönsam. Även under innevarande programperiod 2015–20 har den en viss samhällsekonomisk lönsamhet. Kompensationsstödet ger dock stora samhällsekonomiska förluster, både under perioden 2007–14 och 2015–20. Samhällsekonomiskt sett vore det bra att halvera båda stöden. Kompensationsstödet ger många extra arbetstillfällen i områden med sämre förutsättningar för odling men till hög samhällsekonomisk kostnad. En del av kostnaden är att kompensationsstödet sammanvägt medför ökad miljöbelastning. Per budgetkrona var dock kostnaden relativt låg jämfört med andra arbetsmarknadspolitiska åtgärder. Störst betydelse för stödens samhällsekonomiska lönsamhet är deras klimateffekter, att deras skattefinansiering ger förluster i annan verksamhet, och att de leder till mindre effektiv jordbruksproduktion av marknadsvaror. Effekterna av stöden beror mycket på de ekonomiska förutsättningarna i övrigt, till exempel prisnivån för jordbruksprodukter på världsmarknaden. Utfallet kan bli ett annat än väntat om förutsättningarna ändras under perioden. Detta hände under perioden 2007–2014.
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| 35. |
- Hass, Annika L., et al.
(author)
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Landscape configurational heterogeneity by small-scale agriculture, not crop diversity, maintains pollinators and plant reproduction in western Europe
- 2018
-
In: Proceedings of the Royal Society B: Biological Sciences. - : The Royal Society. - 0962-8452 .- 1471-2954. ; 285:1872
-
Journal article (peer-reviewed)abstract
- Agricultural intensification is one of the main causes for the current biodiversity crisis. While reversing habitat loss on agricultural land is challenging, increasing the farmland configurational heterogeneity (higher field border density) and farmland compositional heterogeneity (higher crop diversity) has been proposed to counteract some habitat loss. Here, we tested whether increased farmland configurational and compositional heterogeneity promote wild pollinators and plant reproduction in 229 landscapes located in four major western European agricultural regions. High-field border density consistently increased wild bee abundance and seed set of radish (Raphanus sativus), probably through enhanced connectivity. In particular, we demonstrate the importance of crop-crop borders for pollinator movement as an additional experiment showed higher transfer of a pollen analogue along crop-crop borders than across fields or along semi-natural crop borders. By contrast, high crop diversity reduced bee abundance, probably due to an increase of crop types with particularly intensive management. This highlights the importance of crop identity when higher crop diversity is promoted. Our results show that small-scale agricultural systems can boost pollinators and plant reproduction. Agri-environmental policies should therefore aim to halt and reverse the current trend of increasing field sizes and to reduce the amount of crop types with particularly intensive management.
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| 36. |
- Hass, Annika Louise, et al.
(author)
-
Maize-dominated landscapes reduce bumblebee colony growth through pollen diversity loss
- 2019
-
In: Journal of Applied Ecology. - : Wiley. - 0021-8901 .- 1365-2664. ; 56:2, s. 294-304
-
Journal article (peer-reviewed)abstract
- Bumblebees are important pollinators for a wide range of crops and wild plants. Performance of their colonies depends on pollen and nectar as food resources, but flowering plants are scarce in modern agricultural landscapes. It is well-known that semi-natural habitats can enhance floral resources and bumblebee abundance, but the impact of different crop types and their heterogeneity at the landscape scale remains unclear. We tested the effect of two different crop types (oilseed rape [OSR] and maize) and of configurational (field border density) and compositional heterogeneity (crop diversity) on weight gain of buff-tailed bumblebee colonies (Bombus terrestris) and the pollen diversity collected by them in 20 landscapes in Central Germany. We found that augmenting maize cover had a detrimental effect on pollen diversity collected by bumblebees, probably due to intensive management resulting in low plant diversity. This low pollen diversity translated into reduced colony growth, since colonies with high pollen diversity gained more weight than colonies with low pollen diversity. In contrast, OSR cover and configurational and compositional heterogeneity did neither affect colony growth nor pollen diversity. However, for OSR, the timing of the flowering period was important. When OSR fields had a high flower cover at the end of the OSR blooming period, colonies showed increased growth rates. Synthesis and applications. Our results complement previous laboratory studies by showing that high pollen diversity leads to better colony performance under field conditions. Therefore, the maintenance of floral diversity in agricultural landscapes is crucial to ensure that bumblebees can fulfil their nutritional needs. However, the heterogeneity of crops, at least under the currently very low levels of crop rotation, does not contribute to this aim. In contrast, crop identity and timing of mass-flowering crops turned out to be important factors, as maize reduced pollen resources, while late blooming oilseed rape (OSR) was beneficial to bumblebee colonies. Hence, maize cover per landscape should be reduced and strategies to enhance landscape wide flower diversity, especially towards and after the end of oilseed rape bloom, should be promoted to support bumblebee colonies that provide important pollination services.
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| 37. |
- Hederström, Veronica, et al.
(author)
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Pollinator-mediated effects of landscape-scale land use on grassland plant community composition and ecosystem functioning – seven hypotheses
- 2024
-
In: Biological Reviews. - 1464-7931. ; 99:3, s. 675-698
-
Journal article (peer-reviewed)abstract
- Environmental change is disrupting mutualisms between organisms worldwide. Reported declines in insect populations and changes in pollinator community compositions in response to land use and other environmental drivers have put the spotlight on the need to conserve pollinators. While this is often motivated by their role in supporting crop yields, the role of pollinators for reproduction and resulting taxonomic and functional assembly in wild plant communities has received less attention. Recent findings suggest that observed and experimental gradients in pollinator availability can affect plant community composition, but we know little about when such shifts are to be expected, or the impact they have on ecosystem functioning. Correlations between plant traits related to pollination and plant traits related to other important ecosystem functions, such as productivity, nitrogen uptake or palatability to herbivores, lead us to expect non-random shifts in ecosystem functioning in response to changes in pollinator communities. At the same time, ecological and evolutionary processes may counteract these effects of pollinator declines, limiting changes in plant community composition, and in ecosystem functioning. Despite calls to investigate community- and ecosystem-level impacts of reduced pollination, the study of pollinator effects on plants has largely been confined to impacts on plant individuals or single-species populations. With this review we aim to break new ground by bringing together aspects of landscape ecology, ecological and evolutionary plant–insect interactions, and biodiversity–ecosystem functioning research, to generate new ideas and hypotheses about the ecosystem-level consequences of pollinator declines in response to land-use change, using grasslands as a focal system. Based on an integrated set of seven hypotheses, we call for more research investigating the putative pollinator-mediated links between landscape-scale land use and ecosystem functioning. In particular, future research should use combinations of experimental and observational approaches to assess the effects of changes in pollinator communities over multiple years and across species on plant communities and on trait distributions both within and among species.
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| 38. |
- Hristov, Jordan, et al.
(author)
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Impacts of the EU's Common Agricultural Policy “Greening” Reform on Agricultural Development, Biodiversity, and Ecosystem Services
- 2020
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In: Applied Economic Perspectives and Policy. - : Wiley. - 2040-5790 .- 2040-5804. ; 42:4, s. 716-738
-
Journal article (peer-reviewed)abstract
- The EU's Common Agricultural Policy (CAP) has had limited success in mitigating agriculture's environmental degradation. In this paper we simulate the impacts of the 2013 “greening” reform on biodiversity and ecosystem services in environmentally contrasting landscapes. We do this by integrating an agent-based model of structural change with spatial ecological production functions, and show that the reform will likely fail to deliver substantial environmental benefits. Our study implies that greening measures need to be tailored to local conditions and priorities, to generate environmental improvements. Such spatial targeting of measures is though incompatible with the design of a common direct payments scheme.
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| 39. |
- Häussler, Johanna, et al.
(author)
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Pollinator population size and pollination ecosystem service responses to enhancing floral and nesting resources
- 2017
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In: Ecology and Evolution. - : Wiley. - 2045-7758. ; 7:6, s. 1898-1908
-
Journal article (peer-reviewed)abstract
- Modeling pollination ecosystem services requires a spatially explicit, process-based approach because they depend on both the behavioral responses of pollinators to the amount and spatial arrangement of habitat and on the within- and between-season dynamics of pollinator populations in response to land use. We describe a novel pollinator model predicting flower visitation rates by wild central-place foragers (e.g., nesting bees) in spatially explicit landscapes. The model goes beyond existing approaches by: (1) integrating preferential use of more rewarding floral and nesting resources; (2) considering population growth over time; (3) allowing different dispersal distances for workers and reproductives; (4) providing visitation rates for use in crop pollination models. We use the model to estimate the effect of establishing grassy field margins offering nesting resources and a low quantity of flower resources, and/or late-flowering flower strips offering no nesting resources but abundant flowers, on bumble bee populations and visitation rates to flowers in landscapes that differ in amounts of linear seminatural habitats and early mass-flowering crops. Flower strips were three times more effective in increasing pollinator populations and visitation rates than field margins, and this effect increased over time. Late-blooming flower strips increased early-season visitation rates, but decreased visitation rates in other late-season flowers. Increases in population size over time in response to flower strips and amounts of linear seminatural habitats reduced this apparent competition for pollinators. Our spatially explicit, process-based model generates emergent patterns reflecting empirical observations, such that adding flower resources may have contrasting short- and long-term effects due to apparent competition for pollinators and pollinator population size increase. It allows exploring these effects and comparing effect sizes in ways not possible with other existing models. Future applications include species comparisons, analysis of the sensitivity of predictions to life-history traits, as well as large-scale management intervention and policy assessment.
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| 40. |
- Image, Mike, et al.
(author)
-
Does agri-environment scheme participation in England increase pollinator populations and crop pollination services?
- 2022
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In: Agriculture, Ecosystems and Environment. - : Elsevier BV. - 0167-8809. ; 325
-
Journal article (peer-reviewed)abstract
- Agri-environment schemes are programmes where landholders enter into voluntary agreements (typically with governments) to manage agricultural land for environmental protection and nature conservation objectives. Previous work at local scale has shown that these features can provide additional floral and nesting resources to support wild pollinators, which may indirectly increase floral visitation to nearby crops. However, the effect of entire schemes on this important ecosystem service has never previously been studied at national scale. Focusing on four wild pollinator guilds (ground-nesting bumblebees, tree-nesting bumblebees, ground-nesting solitary bees, and cavity-nesting solitary bees), we used a state-of-the-art, process-based spatial model to examine the relationship between participation in agri-environment schemes across England during 2016 and the predicted abundances of these guilds and their visitation rates to four pollinator dependent crops (oilseed rape, field beans, orchard fruit and strawberries). Our modelling predicts that significant increases in national populations of ground-nesting bumblebees and ground-nesting solitary bees have occurred in response to the schemes. Lack of significant population increases for other guilds likely reflects specialist nesting resource requirements not well-catered for in schemes. We do not predict statistically significant increases in visitation to pollinator-dependent crops at national level as a result of scheme interventions but do predict some localised areas of significant increase in bumblebee visitation to crops flowering in late spring. Lack of any significant change in visitation to crops which flower outside this season is likely due to a combination of low provision of nesting resource relative to floral resource by scheme interventions and low overall participation in more intensively farmed landscapes. We recommend future schemes place greater importance on nesting resource provision alongside floral resource provision, better cater for the needs of specialised species and promote more contiguous patches of semi-natural habitat to better support solitary bee visitation.
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| 41. |
- Image, Mike, et al.
(author)
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Which interventions contribute most to the net effect of England’s agri-environment schemes on pollination services?
- 2023
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In: Landscape Ecology. - : Springer Science and Business Media LLC. - 0921-2973 .- 1572-9761. ; 38:1, s. 271-291
-
Journal article (peer-reviewed)abstract
- Context: Agri-environment schemes support land management interventions that benefit biodiversity, environmental objectives, and other public goods. Process-based model simulations suggest the English scheme, as implemented in 2016, increased wild bee pollination services to pollinator-dependent crops and non-crop areas in a geographically heterogeneous manner. Objectives: We investigated which interventions drove the scheme-wide predicted pollination service increase to oilseed rape, field beans and non-cropped areas. We determined whether the relative contribution of each intervention was related to floral and/or nesting resource quality of the intervention, area of uptake, or placement in the landscape. Methods: We categorised interventions into functional groups and used linear regression to determine the relationship between predicted visitation rate increase and each category’s area within a 10 km grid tile. We compared the magnitude of the regression coefficients to measures of resource quality, area of uptake nationally, and placement to infer the factors underpinning this relationship. Results: Hedgerow/woodland edge management had the largest positive effect on pollination service change, due to high resource quality. Fallow areas were also strong drivers, despite lower resource quality, implying effective placement. Floral margins had limited benefit due to later resource phenology. Interventions had stronger effects where there was less pre-existing semi-natural habitat. Conclusions: Future schemes could support greater and more resilient pollination service in arable landscapes by promoting hedgerow/woodland edge management and fallow interventions. Including early-flowering species and increasing uptake would improve the effect of floral margins. Spatial targeting of interventions should consider landscape context and pairing complimentary interventions to maximise whole-scheme effectiveness.
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| 42. |
- Isgren, Ellinor, 1987, et al.
(author)
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Are agricultural extension systems ready to scale up ecological intensification in East Africa? A literature review with particular attention to the Push-Pull Technology (PPT)
- 2023
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In: Food Security. - 1876-4517. ; 15, s. 1399-1420
-
Journal article (peer-reviewed)abstract
- Agricultural extension, or advisory services, have a key role to play in supporting farmers' learning and adoption of new practices and technologies. This paper analyses gaps and needs which require addressing in order for extension systems to more effectively contribute to the upscaling of ecological intensification approaches in East African smallholder agriculture. Our starting point is the push-pull technology (PPT), a promising approach. PPT originated in East Africa and is being continuously improved through cycles of interdisciplinary and participatory experimentation. Despite well-documented benefits to farmers and the environment, more institutional support from agricultural extension systems (AES) is needed for PPT to realise significant impact on poverty reduction, food security, and sustainability. Departing from this assessment, we review literature on AES in five East African countries. After clarifying the AES characteristics that ecological intensification requires, emphasising the capacity to embrace complexity, we identify four thematic areas that are in urgent need of attention: first, widely recognised problems with access and inclusiveness have seen welcome innovation but remain substantial. Second, information and communication technologies provide many benefits and new possibilities, but expectations must be tempered. Third, pluralistic AES present coordination challenges that risk undermining and misdirecting extension. Finally, the political-economic underpinnings of extension require critical scrutiny and strategic interventions. While many challenges threaten extension effectiveness broadly, we highlight implications for ecological intensification approaches like PPT. Our insights thus speak to the broader question of how to design and implement extension for sustainable agricultural development in East Africa.
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| 43. |
- Jezeer, Rosalien E., et al.
(author)
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Benefits for multiple ecosystem services in Peruvian coffee agroforestry systems without reducing yield
- 2019
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In: Ecosystem Services. - : Elsevier BV. - 2212-0416. ; 40
-
Journal article (peer-reviewed)abstract
- Crop production often comes at the expense of losses in ecosystem services and biodiversity; however, this might not always be the case. Here we test the effects of shade gradients and agricultural inputs on trade-offs or synergies between coffee yield and ecosystem services and biodiversity data for smallholder coffee plantations of Arabica coffee in Peru. We collected data using surveys (n = 162 farmers) and field sampling (n = 62 farms) and modelled the relationship between coffee yield, butterfly species richness and carbon storage, accounting for soil fertility and yield losses to pests and diseases. We found that both carbon and forest butterfly species richness were higher in plantations with more shade, and with no reduction in coffee yields with increasing shade. There were no significant correlations between coffee yield, forest butterfly species richness and carbon storage. Use of agricultural inputs, especially fertilizers, was highest in sites with low coffee yield, but was not related with either forest butterfly species richness or carbon. The lack of trade-offs between yield, forest butterfly species richness and carbon, and their relationships with shade and agricultural inputs suggest that it is possible to manage coffee agroforests to simultaneously provide multiple ecosystem services without reducing coffee yields.
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| 44. |
- Kirchweger, Stefan, et al.
(author)
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Do improved pollination services outweigh farm-economic disadvantages of working in small-structured agricultural landscapes? – Development and application of a bio-economic model
- 2020
-
In: Ecological Economics. - : Elsevier BV. - 0921-8009. ; 169
-
Journal article (peer-reviewed)abstract
- Increases in the size of agricultural fields, the loss of permanent green field edges and other semi-natural habitats have accompanied the intensification of agriculture, and are still ongoing. From a farm economic perspective, an increase in field size increases efficiency mainly due to cost savings. However, recent evidence suggests that increases in field size might lead to the loss of ecosystem services provided by farmland biodiversity, but this trade-off is rarely considered. Here, we aim to quantify the economic and ecological effects of these changes by developing a bio-economic simulation-based land-use modelling framework based on spatially explicit data from an agricultural region in Germany. The results show a substantial decrease in flower visitation in oilseed rape when field sizes increase and permanent green edges are lost. This also leads to a decrease in pollination from wild bees and affects yields and farm economics. However, this loss in agricultural gross margin is overcompensated by economic gains of field enlargement. We conclude that further, more comprehensive evaluations are required and suggest that maintaining fine-grained agricultural landscapes with permanent field margins in the long term may require incentives to farmers, as well as innovations that allow to farm small fields at lower costs.
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| 45. |
- Klatt, Björn, et al.
(author)
-
Bee pollination improves crop quality, shelf life and commercial value.
- 2014
-
In: Royal Society of London. Proceedings B. Biological Sciences. - : The Royal Society. - 1471-2954. ; 281:1775
-
Journal article (peer-reviewed)abstract
- Pollination improves the yield of most crop species and contributes to one-third of global crop production, but comprehensive benefits including crop quality are still unknown. Hence, pollination is underestimated by international policies, which is particularly alarming in times of agricultural intensification and diminishing pollination services. In this study, exclusion experiments with strawberries showed bee pollination to improve fruit quality, quantity and market value compared with wind and self-pollination. Bee-pollinated fruits were heavier, had less malformations and reached higher commercial grades. They had increased redness and reduced sugar-acid-ratios and were firmer, thus improving the commercially important shelf life. Longer shelf life reduced fruit loss by at least 11%. This is accounting for 0.32 billion US$ of the 1.44 billion US$ provided by bee pollination to the total value of 2.90 billion US$ made with strawberry selling in the European Union 2009. The fruit quality and yield effects are driven by the pollination-mediated production of hormonal growth regulators, which occur in several pollination-dependent crops. Thus, our comprehensive findings should be transferable to a wide range of crops and demonstrate bee pollination to be a hitherto underestimated but vital and economically important determinant of fruit quality.
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| 46. |
- Klatt, Björn K., 1980-, et al.
(author)
-
Seed treatment with clothianidin induces changes in plant metabolism and alters pollinator foraging preferences
- 2023
-
In: Ecotoxicology. - New York, NY : Springer. - 0963-9292 .- 1573-3017. ; 32:10, s. 1247-1256
-
Journal article (peer-reviewed)abstract
- Neonicotinoids, systemic insecticides that are distributed into all plant tissues and protect against pests, have become a common part of crop production, but can unintentionally also affect non-target organisms, including pollinators. Such effects can be direct effects from insecticide exposure, but neonicotinoids can affect plant physiology, and effects could therefore also be indirectly mediated by changes in plant phenology, attractiveness and nutritional value. Under controlled greenhouse conditions, we tested if seed treatment with the neonicotinoid clothianidin affected oilseed rape’s production of flower resources for bees and the content of the secondary plant products glucosinolates that provide defense against herbivores. Additionally, we tested if seed treatment affected the attractiveness of oilseed rape to flower visiting bumblebees, using outdoor mesocosms. Flowers and leaves of clothianidin-treated plants had different profiles of glucosinolates compared with untreated plants. Bumblebees in mesocosms foraged slightly more on untreated plants. Neither flower timing, flower size nor the production of pollen and nectar differed between treatments, and therefore cannot explain any preference for untreated oilseed rape. We instead propose that this small but significant preference for untreated plants was related to the altered glucosinolate profile caused by clothianidin. Thereby, this study contributes to the understanding of the complex relationships between neonicotinoid-treated crops and pollinator foraging choices, by suggesting a potential mechanistic link by which insecticide treatment can affect insect behavior.
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| 47. |
- Le Provost, Gaëtane, et al.
(author)
-
Land-use history impacts functional diversity across multiple trophic groups
- 2020
-
In: Proceedings of the National Academy of Sciences of the United States of America. - : Proceedings of the National Academy of Sciences. - 0027-8424. ; 117:3, s. 1573-1579
-
Journal article (peer-reviewed)abstract
- Land-use change is a major driver of biodiversity loss worldwide. Although biodiversity often shows a delayed response to land-use change, previous studies have typically focused on a narrow range of current landscape factors and have largely ignored the role of land-use history in shaping plant and animal communities and their functional characteristics. Here, we used a unique database of 220,000 land-use records to investigate how 20-y of land-use changes have affected functional diversity across multiple trophic groups (primary producers, mutualists, herbivores, invertebrate predators, and vertebrate predators) in 75 grassland fields with a broad range of land-use histories. The effects of land-use history on multitrophic trait diversity were as strong as other drivers known to impact biodiversity, e.g., grassland management and current landscape composition. The diversity of animal mobility and resourceacquisition traits was lower in landscapes where much of the land had been historically converted from grassland to crop. In contrast, functional biodiversity was higher in landscapes containing old permanent grasslands, most likely because they offer a stable and high-quality habitat refuge for species with low mobility and specialized feeding niches. Our study shows that grassland-to-crop conversion has long-lasting impacts on the functional biodiversity of agricultural ecosystems. Accordingly, land-use legacy effects must be considered in conservation programs aiming to protect agricultural biodiversity. In particular, the retention of permanent grassland sanctuaries within intensive landscapes may offset ecological debts.
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| 48. |
- Lichtenberg, Elinor M., et al.
(author)
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A global synthesis of the effects of diversified farming systems on arthropod diversity within fields and across agricultural landscapes
- 2017
-
In: Global Change Biology. - : Wiley. - 1354-1013 .- 1365-2486. ; 23:11, s. 4946-4957
-
Journal article (peer-reviewed)abstract
- Agricultural intensification is a leading cause of global biodiversity loss, which can reduce the provisioning of ecosystem services in managed ecosystems. Organic farming and plant diversification are farm management schemes that may mitigate potential ecological harm by increasing species richness and boosting related ecosystem services to agroecosystems. What remains unclear is the extent to which farm management schemes affect biodiversity components other than species richness, and whether impacts differ across spatial scales and landscape contexts. Using a global metadataset, we quantified the effects of organic farming and plant diversification on abundance, local diversity (communities within fields), and regional diversity (communities across fields) of arthropod pollinators, predators, herbivores, and detritivores. Both organic farming and higher in-field plant diversity enhanced arthropod abundance, particularly for rare taxa. This resulted in increased richness but decreased evenness. While these responses were stronger at local relative to regional scales, richness and abundance increased at both scales, and richness on farms embedded in complex relative to simple landscapes. Overall, both organic farming and in-field plant diversification exerted the strongest effects on pollinators and predators, suggesting these management schemes can facilitate ecosystem service providers without augmenting herbivore (pest) populations. Our results suggest that organic farming and plant diversification promote diverse arthropod metacommunities that may provide temporal and spatial stability of ecosystem service provisioning. Conserving diverse plant and arthropod communities in farming systems therefore requires sustainable practices that operate both within fields and across landscapes.
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| 49. |
- Maas, Bea, et al.
(author)
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Avian species identity drives predation success in tropical cacao agroforestry
- 2015
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In: Journal of Applied Ecology. - : Wiley. - 1365-2664 .- 0021-8901. ; 52:3, s. 735-743
-
Journal article (peer-reviewed)abstract
- Avian ecosystem services such as the suppression of pests are considered to be of high ecological and economic importance in a range of ecosystems, especially in tropical agroforestry. However, how bird predation success is related to the diversity and composition of the bird community, as well as local and landscape factors, is poorly understood. We quantified arthropod predation in relation to the identity and diversity of insectivorous birds using experimental exposure of artificial, caterpillar-like prey in 15 smallholder cacao agroforestry systems differing in local shade-tree management and distance to primary forest. The bird community was assessed using both mist-netting (targeting active understorey insectivores) and point counts (higher completeness of species inventories). Bird predation was not related to local shade-tree management or overall bird species diversity, but to the activity of insectivorous bird species and the proximity to primary forest. Insectivore activity was best predicted by mist-netting-based data, not by point counts. We identified the abundant Indonesian endemic lemon-bellied white-eye Zosterops chloris as the main driver of predation on artificial prey.Synthesis and applications. The suppression of arthropods is a major ecosystem service provided by insectivorous birds in agricultural systems world-wide, potentially reducing herbivore damage on plants and increasing yields. Our results show that avian predation success can be driven by single and abundant insectivorous species, rather than by overall bird species richness. Forest proximity was important for enhancing the density of this key species, but did also promote bird species richness. Hence, our findings are both of economical as well as ecological interest because the conservation of nearby forest remnants will likely benefit human needs and biodiversity conservation alike. The suppression of arthropods is a major ecosystem service provided by insectivorous birds in agricultural systems world-wide, potentially reducing herbivore damage on plants and increasing yields. Our results show that avian predation success can be driven by single and abundant insectivorous species, rather than by overall bird species richness. Forest proximity was important for enhancing the density of this key species, but did also promote bird species richness. Hence, our findings are both of economical as well as ecological interest because the conservation of nearby forest remnants will likely benefit human needs and biodiversity conservation alike.
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| 50. |
- Marthy, William, et al.
(author)
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Assessing the biodiversity value of degraded lowland forest in Sumatra, Indonesia
- 2016
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In: Kukila. - 0216-9223. ; 19:1, s. 1-20
-
Journal article (peer-reviewed)abstract
- Forest degradation, forest fires, and wildlife poaching have devastated biodiversity in Indonesia. To assess the impact of forest degradation and the potential for recovery, we used birds as a proxy for biodiversity and assessed density estimates (hereafter density) in the degraded lowland forest of Harapan Rainforest Ecosystem Restoration Concession (HRF) in Sumatra. In this study, a total of 149 bird species (from 5,317 individuals) were recorded. Of the 103 species for which densities could be calculated, 45% were lowland bird specialists (i.e. species occurring below 200 m above sea level in Sumatra), including three globally threatened and 41 Near-Threatened species. Comparison with bird densities in degraded forest of Borneo revealed that there was broad similarity across taxa but three species had significantly higher density, and four had significantly lower density, in HRF. The mosaic of degraded forest habitats in different stages of regeneration in HRF appears to support more individuals of some species, especially woodpeckers, than the Bornean sites, but fewer individuals of other species. Determining bird densities is essential to establish population baselines, allowing comparisons between sites and over time. The present study fills one gap, but we urge others to conduct similar studies to provide a better understanding of the temporal and spatial variation in bird density in Southeast Asia's degraded forests.
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