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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.

Bewässerte Reisanbaugebiete gehören zu den biologisch vielfältigsten globalen Agrarökosystemen. Allerdings ist diese Biodiversität gefährdet durch landwirtschaftliche Intensivierung und monokultureller Verarmung von Anbauflächen, welche einen Abbau von Ökosystemleistungen, wie natürliche Schädlingsregulierung, nach sich ziehen. Während Nachweise zeigen, dass unehmende Heterogenität der Landschaft von Agrarökosystemen zur Erhöhung von Feindpopulationen und Verbesserung biologischer Kontrolle führen kann, ist wenig bekannt über Multiskalen-Effekte von Landschaftzusammensetzung und -konfiguration auf Arthropodengemeinschaften in Reis-Agrarökosystemen. In dieser Dissertation untersuchte ich den Einfluss von Landschaftsheterogenität auf die Verteilung von Athropoden in drei philippinischen Reisanbauregionen, um Empfehlungen für den Erhalt von Biodiversität und Verbesserung biologischer Kontrolle in Reis-Agrarökosystemen zu geben. In den verschiedenen Kapiteln der Dissertation, habe ich die Landschaftsheterogenität auf verschiedenen Skalen gemessen und deren Auswirkung auf die Arthropodendiversität (taxonomische und funktionelle Diversität) getestet.

Bewässerte Reisanbaugebiete gehören zu den biologisch vielfältigsten globalen Agrarökosystemen. Allerdings ist diese Biodiversität gefährdet durch landwirtschaftliche Intensivierung und monokultureller Verarmung von Anbauflächen, welche einen Abbau von Ökosystemleistungen, wie natürliche Schädlingsregulierung, nach sich ziehen. Während Nachweise zeigen, dass unehmende Heterogenität der Landschaft von Agrarökosystemen zur Erhöhung von Feindpopulationen und Verbesserung biologischer Kontrolle führen kann, ist wenig bekannt über Multiskalen-Effekte von Landschaftzusammensetzung und -konfiguration auf Arthropodengemeinschaften in Reis-Agrarökosystemen. In dieser Dissertation untersuchte ich den Einfluss von Landschaftsheterogenität auf die Verteilung von Athropoden in drei philippinischen Reisanbauregionen, um Empfehlungen für den Erhalt von Biodiversität und Verbesserung biologischer Kontrolle in Reis-Agrarökosystemen zu geben. In den verschiedenen Kapiteln der Dissertation, habe ich die Landschaftsheterogenität auf verschiedenen Skalen gemessen und deren Auswirkung auf die Arthropodendiversität (taxonomische und funktionelle Diversität) getestet.

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.

AbstractThe 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.

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.

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.

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 wellcatered 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 ...

1. 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 hetero-geneity of the crop mosaic itself, hereafter referred to as crop heterogeneity, can have beneficial effects on within-field plant diversity .2. 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 heteroge-neity on within-field plant diversity components. We also examined how these relationships were modulated by the position within the field. 3. 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. 4. Synthesis and applications. Our study shows that increasing configurational crop heterogeneity is beneficial to within-field plant diversity. It opens up a new effec-tive 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 con-servation of farmland plant diversity. ; Natural Sciences and Engineering Research Council of Canada; German Ministry of Research and Education; Agence Nationale de la Recherche, Grant/Award Number: ANR-11-EBID-0004; Canada Foundation for Innovation; German Research Foundation; Spanish Ministry of Economy and Competitiveness; Agriculture and Agri-Food Canada; French National Research Agency, Grant/Award Number: ANR-11-EBID-0004; UK Government Department of the Environment, Food and Rural Affairs; Environment Canada (EC)

Agricultural landscape homogenization has detrimental effects on biodiversity and key ecosystem services. Increasing agricultural landscape heterogeneity by increasing seminatural cover can help to mitigate biodiversity loss. However, the amount of seminatural cover is generally low and difficult to increase in many intensively managed agricultural landscapes. We hypothesized that increasing the heterogeneity of the crop mosaic itself (hereafter "crop heterogeneity") can also have positive effects on biodiversity. In 8 contrasting regions of Europe and North America, we selected 435 landscapes along independent gradients of crop diversity and mean field size. Within each landscape, we selected 3 sampling sites in 1, 2, or 3 crop types. We sampled 7 taxa (plants, bees, butterflies, hoverflies, carabids, spiders, and birds) and calculated a synthetic index of multitrophic diversity at the landscape level. Increasing crop heterogeneity was more beneficial for multitrophic diversity than increasing seminatural cover. For instance, the effect of decreasing mean field size from 5 to 2.8 ha was as strong as the effect of increasing seminatural cover from 0.5 to 11%. Decreasing mean field size benefited multitrophic diversity even in the absence of seminatural vegetation between fields. Increasing the number of crop types sampled had a positive effect on landscape-level multitrophic diversity. However, the effect of increasing crop diversity in the landscape surrounding fields sampled depended on the amount of seminatural cover. Our study provides large-scale, multitrophic, cross-regional evidence that increasing crop heterogeneity can be an effective way to increase biodiversity in agricultural landscapes without taking land out of agricultural production. ; This research was funded by the ERA-Net BiodivERsA, with the national funders French National Research Agency (ANR-11-EBID-0004), German Ministry of Research and Education, German Research Foundation and Spanish Ministry of Economy and Competitiveness, part of the 2011 BiodivERsA call for research proposals. The UK component of this research was funded by the UK Government Department of the Environment, Food and Rural Affairs (Defra), as Project WC1034. The Canadian component of this research was funded by a Natural Sciences and Engineering Research Council of Canada Strategic Project, the Canada Foundation for Innovation, Environment Canada, and Agriculture and Agri-Food Canada. N.G. was supported by the AgreenSkills+ Fellowship programme which has received funding from the EU's Seventh Framework Programme under Grant Agreement FP7-609398 (AgreenSkills+ contract). A.G.-T. (Juan de la Cierva Fellow, JCI-2012-12089) was funded by Ministerio de Economía y Competitividad (Spain). C. Violle was supported by the European Research Council Starting Grant Project "Ecophysiological and biophysical constraints on domestication of crop plants" (Grant ERC-StG-2014-639706-CONSTRAINTS). A.R.'s position at the University of Alicante is funded by the "Vicerrectorado de Investigación y Transferencia de Conocimiento."