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Floral resources are known to be important in regulating wild pollinator populations and are therefore an important component of agri‐environment and restoration schemes which aim to support pollinators and their associated services. However, the phenology of floral resources is often overlooked in these schemes — a factor which may be limiting their success. Our study characterizes and quantifies the phenology of nectar resources at the whole‐farm scale on replicate farms in Southwestern UK throughout the flowering season. We quantify the corresponding nectar demands of a subset of common wild pollinators (bumblebees) to compare nectar supply and pollinator demand throughout the year, thereby identifying periods of supply‐demand deficit. We record strong seasonal fluctuations in farmland nectar supplies, with two main peaks of nectar production (May and July) and a considerable “June Gap” in between. March and August/September are also periods of low nectar availability. Comparing the phenology of nectar supply with the phenology of bumblebee nectar demand reveals “hunger gaps” during March and much of August/September when supply is unlikely to meet demand. Permanent pasture and woodland produced the greatest share of farmland nectar because of their large area; however, linear features such as hedgerows and field margins provided the greatest nectar per unit area. Fifty percent of total nectar was supplied by just three species (Allium ursinum, Cirsium arvense and Trifolium repens), but some less productive species (e.g. Hedera helix and Taraxacum agg.) were important in ensuring phenological continuity of nectar supply. Synthesis and applications. By comparing the phenology of farmland nectar supply with the phenology of pollinator demand, we demonstrate that the timing of nectar supply may be as important as total nectar production in limiting farmland pollinator populations. Considering phenology in the design of agri‐environment or restoration schemes is therefore likely to improve their suitability for pollinators. Plant species which flower during periods of resource deficit (early spring and late summer) should be prioritized in schemes which aim to conserve or restore pollinator populations. Maintaining a range of semi‐natural habitats with complementary flowering phenologies (e.g. woodland, hedgerows and field margins) will ensure a more continuous supply of nectar on farmland, thereby supporting pollinators for their entire flight season. By comparing the phenology of farmland nectar supply with the phenology of pollinator demand, we demonstrate that the timing of nectar supply may be as important as total nectar production in limiting farmland pollinator populations. Considering phenology in the design of agri‐environment or restoration schemes is therefore likely to improve their suitability for pollinators. Plant species which flower during periods of resource deficit (early spring and late summer) should be prioritized in schemes which aim to conserve or restore pollinator populations. Maintaining a range of semi‐natural habitats with complementary flowering phenologies (e.g. woodland, hedgerows and field margins) will ensure a more continuous supply of nectar on farmland, thereby supporting pollinators for their entire flight season.

Summary This review assesses current knowledge about the interplay between landscape and pollinator communities. Our primary aim is to provide an evidence base, identify key gaps in knowledge and highlight initiatives that will help develop and improve strategies for pollinator conservation. Human‐dominated landscapes (such as arable land and urban environments) can have detrimental impacts on pollinator communities but these negative effects can be ameliorated by proximity to semi‐natural habitat and habitat corridors. There is also evidence to suggest that increased landscape heterogeneity and landscape configuration can play an important role in the maintenance of diverse pollinator communities. Landscape characteristics have direct impacts on pollinator communities, but can also influence abundance and richness through interaction with other drivers such as changing climate or increased chemical inputs in land management. The majority of existing literature focuses on specific hymenopteran groups, but there is a lack of information on the impact of landscape changes on non‐bee taxa. Research is also needed on the effectiveness of management interventions for pollinators and multiple year observations are required for both urban and rural initiatives. Current policies and monitoring schemes could contribute data that will plug gaps in knowledge, thus enabling greater understanding of relationships between landscapes and pollinator populations. This would in turn help design mitigation and adaptation strategies for pollinator conservation. A lay summary is available for this article. Lay Summary

The European Union's Common Agricultural Policy (CAP) has not halted farmland biodiversity loss. The CAP post‐2023 has a new ‘‘Green Architecture,’’ including the new ‘‘Eco‐scheme’’ instrument. How can this new Green Architecture help tackle the biodiversity crisis? Through 13 workshops and an online survey, over 300 experts from 23 European Member States addressed this question. From experts’ contributions, key principles for success include preserving and restoring (semi)natural elements and extensive grasslands; improving spatial planning and landscape‐scale implementation, including through collective actions; implementing result‐based approaches; and improved knowledge exchange. To maximize the effectiveness of Eco‐scheme for biodiversity, experts highlighted the need to prioritize evidence‐based actions, allocate a sufficient budget for biodiversity, and incentivize management improvements through higher payment levels. Additionally, stronger coherence is needed among CAP instruments. For effective CAP implementation, the European Commission and the Member States should expand investments in biodiversity monitoring, knowledge transfer, and capacity‐building within relevant institutions. The remaining risks in the CAP's ability to reverse the loss of farmland biodiversity still require better design, closer monitoring, greater transparency, and better engagement with farmers. Additionally, greater involvement of scientists is needed to guide the CAP toward restoring farmland biodiversity while accounting for synergies and trade‐offs with other objectives.

1. Organic farming in Europe has been shown to enhance biodiversity locally, but potential interactions with the surrounding landscape and the potential effects on ecosystem services are less well known. 2. In cereal fields on 153 farms in five European regions, we examined how the species richness and abundance of wild plants, ground beetles and breeding birds, and the biological control potential of the area, were affected by organic and conventional farming, and how these effects were modified by landscape complexity (percentage of arable crops within 1000 m of the study plots). Information on biodiversity was gathered from vegetation plots, pitfall traps and by bird territory mapping. The biological control potential was measured as the percentage of glued, live aphids removed from plastic labels exposed in cereal fields for 24 h. 3. Predation on aphids was highest in organic fields in complex landscapes, and declined with increasing landscape homogeneity. The biological control potential in conventional fields was not affected by landscape complexity, and in homogenous landscapes it was higher in conventional fields than in organic fields, as indicated by an interaction between farming practice and landscape complexity. 4. A simplification of the landscape, from 20% to 100% arable land, reduced plant species richness by about 16% and cover by 14% in organic fields, and 33% and 5·5% in conventional fields. For birds, landscape simplification reduced species richness and abundance by 34% and 32% in organic fields and by 45·5% and 39% in conventional fields. Ground beetles were more abundant in simple landscapes, but were unaffected by farming practice. 5. Synthesis and applications. This Europe-wide study shows that organic farming enhanced the biodiversity of plants and birds in all landscapes, but only improved the potential for biological control in heterogeneous landscapes. These mixed results stress the importance of taking both local management and regional landscape complexity into consideration when developing future agri-environment schemes, and suggest that local-regional interactions may affect other ecosystem services and functions. This study also shows that it is not enough to design and monitor agri-environment schemes on the basis of biodiversity, but that ecosystem services should be considered too.

1. Sown flower strips are increasingly implemented within agri-environment schemes (AES) to increase functional biodiversity and ecosystem services such as pollination or natural pest control, but their effectiveness in achieving these goals remains poorly studied. 2. We tested the performance of experimentally sown annual flower strips specifically designed to promote natural enemies of aphids and their pest control services (tailored flower strips) in adjacent potato crops (n = 8) compared with control fields (n = 10). Flower strips consisted of 11 plant species providing abundant floral and extra-floral resources. 3. The abundance of key natural enemies of aphids (hoverflies, lacewings and ladybirds) and hoverfly species richness was greatly enhanced in tailored flower strips compared with potato control strips. This resulted in an average increase in the number of eggs deposited by hoverflies and lacewings by 127% and 48%, respectively, and a reduction in the number of aphids by 75% in adjacent potato crops. 4. Synthesis and applications. We conclude that tailored flower strips can be an effective agrienvironmental measure to enhance natural enemies and aphid control in nearby crops. Indeed, tailored flower strips may help to reduce insecticide input in potato production as they significantly decrease the probability that action thresholds are reached. Promoting natural enemy abundance and diversity, as observed for hoverflies, may increase the stability of pest control and provide additional benefits to agro-ecosystems in terms of natural enemy conservation. We thus recommend establishing tailored flower strips as a promising management option to reconcile the objectives of ecological intensification and biodiversity conservation.

1. Enhancing key floral resources is essential to effectively mitigate the loss of pollinator diversity and associated provisioning of pollination functions in agro-ecosystems. However, effective floral provisioning measures may diverge among different pollinator conservation targets, such as the conservation of rare species or the promotion of economically important crop pollinators. We examined to what extent such diverging conservation goals could be reconciled. 2. We analysed plant-bee visitation networks of 64 herbaceous semi-natural habitats representing a gradient of plant species richness to identify key resource plants of the three distinct conservation target groups: rare bees (of conservation concern), dominant wild croppollinating bees and managed crop-pollinating bees (i.e. honeybees). 3. Considering overall flower visitation, rare bees tended to visit nested subsets of plant species that were also visited by crop pollinators (46% and 77% nestedness in the dissimilarity between rare bees and wild crop pollinators or managed honeybees respectively). However, the set of preferred plant species, henceforth 'key plant species' (i.e. those species disproportionately more visited than expected according to their floral abundance) was considerably more distinct and less nested among bee target groups. 4. Flower visits of all bee target groups increased with plant species richness at a similar rate. Importantly, our analyses revealed that an exponential increase in the flower abundance of the identified key plant species and complementarity in the bee visitation pattern across plant species — rather than total flower abundance — were the major drivers of these relationships. 5. Synthesis and applications. We conclude that the multiple goals of preserving high bee diversity, conserving rare species and sustaining crop pollinators can be reconciled if key plant species of different target groups are simultaneously available. This availability is facilitated by a high floral resource complementarity in the plant community. The list of identified key resource plant species we provide here can help practitioners such as land managers and conservationists to better design and evaluate pollinator conservation and restoration measures according to their goals. Our findings highlight the importance of identifying and promoting such plant species for pollinator conservation in agricultural landscapes.

Growing evidence for declines in wild bees calls for the development and implementation of effective mitigation measures. Enhancing floral resources is a widely accepted measure for promoting bees in agricultural landscapes, but effectiveness varies considerably between landscapes and regions. We hypothesize that this variation is mainly driven by a combination of the direct effects of measures on local floral resources and the availability of floral resources in the surrounding landscape. To test this, we established wildflower strips in four European countries, using the same seed mixture of forage plants specifically targeted at bees. We used a before–after control–impact approach to analyse the impacts of wildflower strips on bumblebees, solitary bees and Red List species and examined to what extent effects were affected by local and landscape‐wide floral resource availability, land‐use intensity and landscape complexity. Wildflower strips generally enhanced local bee abundance and richness, including Red‐listed species. Effectiveness of the wildflower strips increased with the local contrast in flower richness created by the strips and furthermore depended on the availability of floral resources in the surrounding landscape, with different patterns for solitary bees and bumblebees. Effects on solitary bees appeared to decrease with increasing amount of late‐season alternative floral resources in the landscape, whereas effects on bumblebees increased with increasing early‐season landscape‐wide floral resource availability. Synthesis and applications. Our study shows that the effects of wildflower strips on bees are largely driven by the extent to which local flower richness is increased. The effectiveness of this measure could therefore be enhanced by maximizing the number of bee forage species in seed mixtures, and by management regimes that effectively maintain flower richness in the strips through the years. In addition, for bumblebees specifically, our study highlights the importance of a continuous supply of food resources throughout the season. Measures that enhance early‐season landscape‐wide floral resource availability, such as the cultivation of oilseed rape, can benefit bumblebees by providing the essential resources for colony establishment and growth in spring. Further research is required to determine whether, and under what conditions, wildflower strips result in actual population‐level effects.

1. Changes in agricultural practice across Europe and North America have been associated with range contractions and a decline in the abundance of wild bees. Concerns at these declines have led to the development of flower-rich agri-environment schemes as a way to enhance bee diversity and abundance. Whilst the effect of these schemes on bumblebee species (Bombus spp.) has been well studied, their impact on the wider bee community is poorly understood. 2. We used direct observations of foraging bees and pollen load analysis to quantify the relative contribution that sown flowers (i.e. those included in agri-environment scheme seed mixes) make to the pollen diets of wild solitary bees on Higher Level Stewardship farms (HLS) implementing pollinator-focused schemes and on Entry Level Stewardship farms (ELS) without such schemes in southern England, UK. 3. HLS management significantly increased floral abundance, and as the abundance of sown flowers increased, these sown plants were utilized for pollen by a greater proportion of the solitary bee species present. However, the overall proportion of pollen collected from sown plants was low for both direct observations (27.0%) and pollen load analysis (23.3%). 4. At most only 25 of the 72 observed species of solitary bee (34.7%) were recorded utilizing sown plants to a meaningful degree. The majority of solitary bee species did not collect pollen from flower species sown for pollinators. 5. Total bee species richness was significantly associated with plant species richness, but there was no difference in the total species richness of either bee or flowering plant species between HLS and ELS farms. 6. Synthesis and applications. Our results show that the majority of solitary bee species present on farmland in the south-east of England collect most of their pollen from plants that persist unaided in the wider environment, and not from those included in agri-environment schemes focused on pollinators. If diverse bee communities are to be maintained on farmland, existing schemes should contain an increased number of flowering plant species and additional schemes that increase the diversity of flowering plants in complementary habitats should be studied and trialled.

A large proportion of European biodiversity today depends on habitat provided by low-intensity farming practices, yet this resource is declining as European agriculture intensifies. Within the European Union, particularly the central and eastern new member states have retained relatively large areas of species-rich farmland, but despite increased investment in nature conservation here in recent years, farmland biodiversity trends appear to be worsening. Although the high biodiversity value of Central and Eastern European farmland has long been reported, the amount of research in the international literature focused on farmland biodiversity in this region remains comparatively tiny, and measures within the EU Common Agricultural Policy are relatively poorly adapted to support it. In this opinion study, we argue that, 10 years after the accession of the first eastern EU new member states, the continued under-representation of the low-intensity farmland in Central and Eastern Europe in the international literature and EU policy is impeding the development of sound, evidence-based conservation interventions. The biodiversity benefits for Europe of existing low-intensity farmland, particularly in the central and eastern states, should be harnessed before they are lost. Instead of waiting for species-rich farmland to further decline, targeted research and monitoring to create locally appropriate conservation strategies for these habitats is needed now.

1. Environmental changes may not always result in rapid changes in species distributions, abundances or diversity. In order to estimate the effects of, for example, land-use changes caused by agri-environment schemes (AES) on biodiversity and ecosystem services, information on the time-lag between the application of the scheme and the responses of organisms is essential. 2. We examined the effects of time since transition (TST) to organic farming on plant species richness and butterfly species richness and abundance. Surveys were conducted in cereal fields and adjacent field margins on 60 farms, 20 conventional and 40 organic, in two regions in Sweden. The organic farms were transferred from conventional management between 1 and 25 years before the survey took place. The farms were selected along a gradient of landscape complexity, indicated by the proportion of arable land, so that farms with similar TST were represented in all landscape types. Organism responses were assessed using model averaging. 3. Plant and butterfly species richness was c. 20% higher on organic farms and butterfly abundance was about 60% higher, compared with conventional farms. Time since transition affected butterfly abundance gradually over the 25-year period, resulting in a 100% increase. In contrast, no TST effect on plant or butterfly species richness was found, indicating that the main effect took place immediately after the transition to organic farming. 4. Increasing landscape complexity had a positive effect on butterfly species richness, but not on butterfly abundance or plant species richness. There was no indication that the speed of response to organic farming was affected by landscape complexity. 5. Synthesis and applications. The effect of organic farming on diversity was rapid for plant and butterfly species richness, whereas butterfly abundance increased gradually with time since transition. If time-lags in responses to AESs turn out to be common, long-term effects would need to be included in management recommendations and policy to capture the full potential of such schemes.