Wildflower Areas Research Articles

An evaluation of ‘pollinator-friendly’ wildflower seed mixes in Italy: are they potential vectors of alien plant species?

Wildflower areas are increasingly used in both urban and rural settings to enhance landscape aesthetics and help the conservation of pollinators, whose dramatic decline threatens both ecosystem functioning and agricultural production. Consequently, today many ‘pollinator-friendly’ wildflower seed mixes can be found on the market. Criteria for the design of these mixes are focused on the ability of the plants to attract pollinators, whereas the identity of the plants themselves in terms of their alien or native status is often not adequately considered. Moreover, seed mixes often lack sufficient floral resources in the early spring and late-season months, which are important to sustain pollinators throughout their whole life cycle. In this study, we analyzed 36 ‘pollinator-friendly’ wildflower seed mixes commercially available in Italy in terms of (1) the abundance of native and alien species, (2) the occurrence of locally alien species with reference to three Italian geographic areas (northern, peninsular, and insular Italy), and (3) the flowering period of native and alien species. Most (83%) of the analyzed seed mixes contain species alien to Italy, with three of them also including invasive alien species. Among native species, many (41%) are locally alien to at least one of the geographic areas. Overall, native species provide earlier blooms than alien species and around 35% of the seed mixes lack blooms in early-spring (March) or prolonged throughout autumn (September-November). These findings highlight the widespread use of alien plant species in ‘pollinator-friendly’ wildflower mixes, which poses serious risks for biodiversity and habitat conservation, especially when sown in agricultural areas. We suggest a more careful design and use of such wildflower mixes, promoting a wider adoption of native seeds of local origin and a greater attention to the blooming period. If properly designed, wildflower mixes can represent an effective strategy for biodiversity conservation in both urban and rural areas.

The low survival rate of European hare leverets in arable farmland: evidence from the predation experiment.

The low survival rate of leverets may significantly contribute to steep population declines and slow recovery of European hares (Lepus europaeus). However, the leveret survival rate in farmlands with different landscape structures is poorly understood, and the existing evidence comes mainly from Western Europe. In this study, we explored the survival of leveret hare dummies along linear semi-natural habitats in homogeneous Central European arable farmland during the main part of the European hare reproduction period (March-April) in 2019 and 2020. The survival rate of hare leverets during the 14-day period was only 22.2%, and all predation events were recorded during the first six days of the experiment. Mammalian predators were responsible for 53.1% of predation events, avian predators for 40.8%, and agricultural operations for 6.1%. The red fox (Vulpes vulpes) was the dominant predator in our study area and was the primary cause of leveret dummy mortality (32.7%), but it also had the highest use-intensity and visit frequency of all of the study plots. Predation by avian predators was associated with patches of lower vegetation height and cover (such as plowed fields) and during daylight hours, whereas the opposite was true for mammalian predators. We propose that improving the habitat quality of arable landscapes by increasing the proportion and quality of extensively used non-farmed habitats (e.g., set-asides, wildflower areas, extensive meadows, fallow land, and semi-natural habitats on arable land) providing cover and shelter for leverets could be an effective management measure for reducing predation risk on leverets.

Addressing pollination deficits in orchard crops through habitat management for wild pollinators.

There is increasing evidence that farmers in many areas are achieving below maximum yields due to insufficient pollination. Practical and effective approaches are needed to maintain wild pollinator populations within agroecosystems so they can deliver critical pollination services that underpin crop production. We established nesting and wildflower habitat interventions in 24 UK apple orchards and measured effects on flower-visiting insects and the pollination they provide, exploring how this was affected by landscape context. We quantified the extent of pollination deficits and assessed whether the management of wild pollinators can reduce deficits and deliver improved outcomes for growers over 3years. Wildflower interventions increased solitary bee numbers visiting apple flowers by over 20%, but there was no effect of nesting interventions. Other pollinator groups were influenced by both local and landscape-scale factors, with bumblebees and hoverflies responding to the relative proportion of semi-natural habitat at larger spatial scales (1000 m), while honeybees and other flies responded at 500 m or less. By improving fruit number and quality, pollinators contributed more than £16 k per hectare. However, deficits (where maximum potential was not being reached due to a lack of pollination) were recorded and the extent of these varied across orchards, and from year to year, with a 22% deficit in output in the worst (equivalent to ~£14 k/ha) compared to less than 3% (equivalent to ~£2 k/ha) in the best year. Although no direct effect of our habitat interventions on deficits in gross output was observed, initial fruit set and seed set deficits were reduced by abundant bumblebees, and orchards with a greater abundance of solitary bees saw lower deficits in fruit size. The abundance of pollinators in apple orchards is influenced by different local and landscape factors that interact and vary between years. Consequently, pollination, and the extent of economic output deficits, also vary between orchards and years. We highlight how approaches, including establishing wildflower areas and optimizing the ratio of cropped and non-cropped habitats can increase the abundance of key apple pollinators and improve outcomes for growers.

WITHDRAWN: Sown wildflower areas for biodiversity conservation and multifunctional agricultural landscapes

WITHDRAWN: Sown wildflower areas for biodiversity conservation and multifunctional agricultural landscapes

Sown wildflower areas for biodiversity conservation and multifunctional agricultural landscapes

Sown wildflower areas for biodiversity conservation and multifunctional agricultural landscapes

WITHDRAWN: Sown wildflower areas for biodiversity conservation and multifunctional agricultural landscapes

This article has been withdrawn at the request of the author(s) and/or editor. The Publisher apologizes for any inconvenience this may cause. The full Elsevier Policy on Article Withdrawal can be found at https://www.elsevier.com/about/our-business/policies/article-withdrawal .

Partitioning of arthropod species diversity in temperate meadows, wildflower areas and pastures

To counteract the rapidly ongoing species decline in modern agroecosystems, most European countries have developed and adopted agri-environment schemes. The efficiency of these schemes, however, ranges from successful to nearly ineffective. To estimate the efficiency of the Swiss agri-environment scheme in particular, we investigated the contribution of extensively managed pastures and meadows and wildflower areas to beetle, heteropteran bug and spider diversity. Extensively managed meadows were shown to contribute most to landscape-scale richness (highest species richness for beetles and bugs), followed by wildflower areas (bugs). Meadows harboured approximately twice as many beetle species unique to this habitat type than wildflower areas and pastures. Bug species unique to a specific habitat type were similar between meadows and wildflower areas, but much lower (approximately 30%) in pastures. To increase beetle species richness, extensively managed meadows should be represented more often in the landscape because meadows harboured the highest number of species and most uniquely found species. To increase species richness of true bugs, both meadows and wildflower areas should be represented more often in the landscape because they harboured more species and more uniquely found species compared to pastures. Across arthropod taxa and habitat types, β diversity was more important for γ diversity than α diversity, indicating that distinctiveness, rather than within-site diversity, was key in determining the contribution of sites to γ (landscape) diversity. This substantiates the argument that increasing the number of sites is efficient to increase landscape species richness. The turnover component of β diversity was far more important than the nestedness component for all arthropod taxa and habitat types and accounted for 79.0% to 95.4% of total β diversity. In conclusion, extensively managed meadows and wildflower areas should be particularly promoted by the Swiss agri-environment scheme, as they contributed more to landscape species richness and species uniqueness than pastures.

Can novel seed mixes provide a more diverse, abundant, earlier, and longer-lasting floral resource for bees than current mixes?

Several agri-environment schemes aim to improve pollinator diversity and abundance, including the sowing of wildflower areas. These seed mixes are often either low in floral diversity and target few pollinator species (mainly social bees), or high in floral diversity but with limited evidence of good establishment of the component species. In order to support a greater diversity of wild bees in farmland, we need more diverse seed mixes, containing species shown to support a wide diversity of insect pollinators, with good establishment and long flowering periods. Here we trialled two typical seed mixes, a low-diversity Fabaceae-heavy mix (FAB) and a more diverse wildflower mix (WF), against two novel wildflower mixes, one based on literature sources (LT), and one based on first-hand surveys of pollinator attraction to flowers growing on a wildflower farm (WB). Both new mixes were focussed on plants attractive to wild bee species. Replicated field plots were set up on two farms and monitored over three years. Our novel wildflower mixes had higher floral diversity and abundance than the FAB mix, and began flowering earlier, reaching their floral peak before the FAB mix, potentially providing forage for a broader range of pollinators or those with earlier flight seasons. The high floral abundance in LT and WB was driven by annuals in the first year, and then multiple perennials in the second and third year. We identified five perennials from four families (Daucus carota, Leucanthemum vulgare, Geranium pyrenaicum, Lotus corniculatus and Trifolium hybridum) that established well on both farms, are known to be attractive to a diversity of bee species, and thus could be considered as providing a more taxonomically diverse base for creating future mixes. However, the mixes provided few floral resources in April (needed by early-flying wild bees), and more research is required in this area.

Landscape- and time-dependent benefits of wildflower areas to ground-dwelling arthropods

Wildflower areas are a popular agri-environment scheme to counteract agro-biodiversity loss. Yet, their benefits are controversially discussed. Since inconsistent benefits may be owed to landscape context and temporal dynamics, we applied a multi-year study to unravel effects of permanent and transient habitats on ground-dwelling arthropods in wildflower areas and cereal fields.Across three consecutive years, we studied activity density, species richness and community composition of rove beetles, carabid beetles and spiders in ten pairs of wildflower areas and cereal fields along independent gradients of proportions of permanent semi-natural habitats or transient wildflower areas.Arthropod responses to the proportions of permanent semi-natural habitats often followed a hump-shaped pattern, whereas transient wildflower areas seemed to drive linear responses. An interactive effect on rove beetle richness in wildflower areas implies that benefits were highest either at intermediate proportions of permanent semi-natural habitats or at lower proportions, but with additional availability of transient wildflower areas or in landscapes with low proportions of permanent semi-natural habitats, but high proportions of wildflower areas. However, ground-dwelling arthropod activity density or species richness did not systematically increase over the three study years.Our results suggest that both permanent and transient habitats differ in how they affect biodiversity, possibly due to different temporal continuity and resource diversity. Benefits of permanent semi-natural habitats seemed highest at an equilibrium between an increasing resource-related species pool and an increasing diversity dilution, whereas benefits of transient wildflower areas seemed to increase with resource complementarity and connectivity at the landscape scale. Nevertheless, both habitats seem to complement each other and considered in concert, seem to be most effective in promoting benefits of wildflower areas to ground-dwelling arthropods at intermediate landscape complexity. The substantial variation in diversity patterns among years with weather extremes, suggests that optimizing benefits of wildflower areas requires further multi-year studies.

Establishment and management of wildflower areas for insect pollinators in commercial orchards

Sown wildflower areas are increasingly recommended as an agri-environmental intervention measure, but evidence for their success is limited to particular insect groups or hampered by the challenges of establishing seed mixes and maintaining flower abundance over time. We conducted a replicated experiment to establish wildflower areas to support insect pollinators in apple orchards. Over three years, and across 23 commercial UK orchards with and without sown wildflowers, we conducted 828 transect surveys across various non-crop habitats. We found that the abundance of flower-visiting solitary bees, bumblebees, honeybees, and beetles was increased in sown wildflower areas, compared with existing non-crop habitats in control orchards, from the second year following floral establishment. Abundance of hoverflies and other non-syrphid flies was increased in wildflower areas from the first year. Beyond the effect of wildflower areas, solitary bee abundance was also positively related to levels of floral cover in other local habitats within orchards, but neither local nor wider landscape-scale context affected abundance of other studied insect taxa within study orchards. There was a change in plant community composition on the sown wildflower areas between years, and in patterns of flowering within and between years, showing a succession from unsown weedy species towards a dominance of sown species over time. We discuss how the successful establishment of sown wildflower areas and delivery of benefits for different insect taxa relies on appropriate and reactive management practices as a key component of any such agri-environment scheme.

Spatial configuration and landscape context of wildflower areas determine their benefits to pollinator α- and β-diversity

Wildflower areas have become a staple tool within agro-environmental schemes (AES) to counteract pollinator declines. While their role in providing food resources to resident flower-visiting insects is unambiguous, the conservation effectiveness in a landscape context is less clear. Particularly, how multiple vs. single wildflower area utilization differs between simple and complex landscapes is understudied. We examined colonisation and community dynamics of wild bees and hoverflies in 33 newly established wildflower areas across a gradient of landscape complexity (amount of semi-natural habitat) and connectivity (presence of additional wildflower areas) for seven weeks during three consecutive years (one year during and two after establishment). We recorded more than 25% of the wild bee and hoverfly species of Hesse in an area of approx. 10 ha, substantiating the general benefit of wildflower areas to pollinators. While alpha-diversity increased with landscape complexity in isolated wildflower areas, the opposite pattern was observed for connected areas. The low alpha-diversity in complex landscapes indicated a dilution effect between connected sites. The inverse relationship between alpha and beta diversity among wildflower areas within landscapes suggests interspecific trade-offs between local resource conditions and landscape context. Accordingly, the establishment of multiple wildflower areas within AES is advisable to increase connectivity of suitable habitats in simple landscapes. Moreover, adjusting local conditions (plant diversity) to landscape context likely optimizes conservation effectiveness in modern agroecosystems.

Benefits of wildflower areas as overwintering habitats for ground-dwelling arthropods depend on landscape structural complexity

Wildflower areas are a popular agri-environment scheme to counteract the biodiversity loss in agro-ecosystems. While benefits for flower-visiting and predatory insects during the vegetation period were frequently shown, few studies addressed the suitability of wildflower areas as overwintering habitats. Here, we studied the significance of wildflower areas as overwintering habitats and whether their benefits vary with landscape context, i.e. the proportions of permanent semi-natural habitats such as hedges. We selected ten landscapes that encompassed independent gradients of proportions of permanent semi-natural habitats (e.g. hedgerows, ditches) and transient wildflower areas. The centres of the landscapes were pairs of wildflower areas and arable fields on which we sampled overwintering ground-dwelling arthropods by emergence traps. In total, we recorded 2838 overwintering individuals from 115 species of rove and carabid beetles as well as spiders. Abundance of rove beetle larvae, as well as species richness of adult rove beetles and spiders was significantly higher in wildflower areas than in arable fields. With respect to landscape context, abundance and species richness of adult rove beetles showed a hump-shaped relationship with the proportion of permanent semi-natural habitats. The abundance of adult carabid beetles showed a hump-shaped relationship with the proportion of transient wildflower areas, while the abundance of carabid beetle larvae showed a hump-shaped pattern with permanent semi-natural habitats. For the first time we showed that, similar to the vegetation period, benefits of wildflower areas as overwintering habitats for ground-dwelling arthropods depend on both local habitat characteristics as well as landscape context. Benefits of wildflower areas for overwintering were highest in simple landscapes with an intermediate proportion of either permanent semi-natural habitats or transient wildflower areas. Our results suggest that in order to sustainably maintain the functional guild of ground-dwelling arthropods, agricultural landscapes should provide both sown wildflower areas and permanent semi-natural habitats. Our results also support the general claim that semi-natural habitats should at least contribute 10–15% to agricultural landscapes in order to maintain the characteristic biodiversity in modern agro-ecosystems.

The best wildflowers for wild bees

Governmental agri-environment schemes (AES) aim to improve pollinator abundance and diversity on farmland by sowing wildflower seed mixes. These often contain high proportions of Fabaceae, particularly Trifolium (clovers), which are attractive to some bumblebee species, but not to most of the ~ 240 solitary bee species in the UK. Here we identify wildflowers that are attractive to a greater range of wild bee species. Forty-five wildflower species being farmed for commercial seed production on a single farm were surveyed for native bees. Bee walks were conducted through discrete wildflower areas from April until August in 2018. The results indicate that including a range of Apiaceae, Asteraceae, and Geraniaceae in seed mixes would cater for a wide diversity of bee species. A total of 14 wildflower species across nine families attracted 37 out of the 40 bee species recorded on the farm, and accounted for 99.7% of all visitations. Only two of these 14 species are included in current AES pollinator mixes. Unexpectedly, few visits were made by bumblebees to Trifolium spp. (0.5%), despite their being considered an important food source for bumblebees, while Anthyllis vulneraria and Geranium pratense were highly attractive. For solitary bees, Crepis capillaris, Sinapsis arvensis, Convolvulus arvensis and Chaerophyllum temulum were amongst the best performing species, none of which are usually included in sown flower mixes. We suggest that the standard ‘pollinator’ mixes used in AES might be updated to include some of these wildflower species, and trialled as seed mixes on farmland.

Habitat selection by the European hare in arable landscapes: The importance of small-scale habitat structure for conservation.

Agricultural land‐use practices have intensified over the last decades, leading to population declines of various farmland species, including the European hare (Lepus europaeus). In many European countries, arable fields dominate agricultural landscapes. Compared to pastures, arable land is highly variable, resulting in a large spatial variation of food and cover for wildlife over the course of the year, which potentially affects habitat selection by hares. Here, we investigated within‐home‐range habitat selection by hares in arable areas in Denmark and Germany to identify habitat requirements for their conservation. We hypothesized that hare habitat selection would depend on local habitat structure, that is, vegetation height, but also on agricultural field size, vegetation type, and proximity to field edges. Active hares generally selected for short vegetation (1–25 cm) and avoided higher vegetation and bare ground, especially when fields were comparatively larger. Vegetation >50 cm potentially restricts hares from entering parts of their home range and does not provide good forage, the latter also being the case on bare ground. The vegetation type was important for habitat selection by inactive hares, with fabaceae, fallow, and maize being selected for, potentially providing both cover and forage. Our results indicate that patches of shorter vegetation could improve the forage quality and habitat accessibility for hares, especially in areas with large monocultures. Thus, policymakers should aim to increase areas with short vegetation throughout the year. Further, permanent set‐asides, like fallow and wildflower areas, would provide year‐round cover for inactive hares. Finally, the reduction in field sizes would increase the density of field margins, and farming different crop types within small areas could improve the habitat for hares and other farmland species.

Habitat selection and range use of little owls in relation to habitat patterns at three spatial scales

AbstractUnderstanding the rules of habitat selection and the individual behavioural routines in the home‐range is crucial for developing evidence‐based conservation action. We investigated habitat selection and range use of adult little owls Athene noctua in relation to landscape configuration, habitat structure and resource distribution. We determined the preference of habitat structures by VHF‐telemetry. Large‐ and fine‐scale distribution patterns of voles – the main prey during the breeding season – were assessed by transect counts of signs of vole presence. An experiment using artificial perches was carried out to determine the fine‐scale adjustment of the owls' range use in relation to prey abundance and vegetation height. Habitat selection and resource exploitation by little owls were structured at all spatial levels: (1) at the landscape scale, orchards were highly preferred over other areas. This accords with the patchy large‐scale occurrence of voles, which were absent in cropland, but abundant in orchards and grassland; (2) within home‐ranges, the spatial distribution of voles was highly inhomogeneous and structures with high prey abundance were used over‐proportionally; (3) at the scale of foraging sites, little owls preferred patches with low vegetation over those with high prey abundance, establishing that prey availability is the crux. The results suggest that all levels of habitat selection and range use were related to farming practices and affected by current cultivation. Conservation measures should focus on the conservation and restoration of orchards on the landscape level and habitat management measures should focus on grasslands – the main food providers – by creating a mosaic of patches with short grass and tall grass. Together with other habitat structures providing food resources such as field edges, wildflower areas and structures facilitating access to prey, the quality of habitat patches in terms of food availability may be highly improved.

Agri-evironmental schemes and active nest protection can increase hatching success of a reintroduced farmland bird species

Throughout Europe ground-nesting farmland bird species are rapidly declining and have become a conservation concern. Intensive agriculture and high nest predation rates are major factors causing the decline. Species conservation efforts often focus on habitat enhancement to increase the quantity and quality of available habitat structures (habitat enhancement hypothesis) or active nest protection by fencing and predator control (predation mitigation hypothesis). Within the context of a reintroduction project of grey partridges (Perdix perdix) into two regions of Switzerland, we investigated breeding habitat preferences and hatching success in relation to properties of the habitat surrounding the nest. Then we tested whether predator exclusion by fencing can increase hatching success. The location and hatching success of 121 nests were observed by radio-tracking and available habitats in both regions were mapped. Grey partridges preferred nesting habitats in highly heterogeneous wildflower areas, which had been implemented as biodiversity promoting areas (BPA) and nest fencing significantly increased hatching success. Likewise, increased proportions of wildflower BPAs tended to enhance hatching success, which is probably related to higher availability of cover in these structures. Increasing proportions of cover vegetation around the nest had a positive effect on hatching success. Increasing the quality of rural habitats by providing heterogeneous habitat structures as well as reducing predator access to nests by fencing can increase hatching success in grey partridges and is likely to benefit other ground-nesting birds as well. In fact, high amounts of cover vegetation around the nest can compensate for nest fencing by hampering nest depredation.

Establishing Wildflower Pollinator Habitats in Agricultural Farmland to Provide Multiple Ecosystem Services.

Beneficial insects provide critical ecosystem services and in agriculture their contribution in pollination and pest control is widely evident (Losey and Vaughan, 2006; Kremen and Chaplin-Kramer, 2007). Globally, 35% of food production benefits from pollinator services (Klein et al., 2007). In many systems, pollination has been provided by the domesticated honey bee (primarily Apis mellifera), but the reliability of pollination services by wild pollinators is becoming increasingly valued (Garibaldi et al., 2013, 2014). These wild pollinators, the majority of which are bee species, persist independently in the ecosystem by relying on multiple resources to complete their lifecycles (Bohart, 1972). Similarly, natural enemies, such as insect predators and parasitoids, provide vital pest control and also persist independently in the farmscape. Although these beneficial insects are not directly managed for their ecosystem services, the farm landscape surrounding targeted crop fields can be modified to increase their abundance and diversity resulting in increased ecosystem services to support a sustainable agricultural system (Landis et al., 2000; Hannon and Sisk, 2009; Holzschuh et al., 2012). Managing farmscapes for these wild beneficial insects is especially critical as insects are threatened by human-mediated landscape disturbances (Tscharntke et al., 2005). With wild bee populations in decline (Potts et al., 2010), there is increasing interest in managing for wild bees by incorporating pollinator habitat into farmland. The concept of setting aside land specifically for wildlife within a farmscape is not new (Baudry et al., 2000), however, the addition of wildflower plantings or saving natural wildflower areas is a specific strategy that can be adopted for its multi-functionality in supporting both pollinators and natural enemies. It is especially valuable in that it can be modified and designed to fit specific cropping systems, landscapes, and support the lifecycles of a community of unmanaged beneficial insects. Here we consider how these variables have been examined in recent pollinator habitat studies, and discuss additional considerations to optimize wildflower plantings to benefit multiple ecosystem services.

Differentiation of spring carabid beetle assemblages between semi‐natural habitats and adjoining winter wheat

Abstract Semi‐natural habitats are part of agri‐environment programmes throughout Europe. Little is known about activity‐density and assemblage composition of carabid beetles within sown wildflower areas (SWA) compared with conventional grassy field margins and adjoining arable fields. In 10 landscapes, two pairs of winter wheat fields with adjoining SWA and grassy field margin were studied. We compared activity‐density, species richness, ecological traits and assemblage composition of carabids among 20 winter wheat fields, 10 adjoining grassy field margins and 10 adjoining SWA. Beetle activity‐density was higher in wheat fields compared with adjoining semi‐natural habitats regarding total carabids, macropterous, polyphagous‐carnivorous and euryoecious open habitat beetles. Although total species richness (analysis of variance) did not significantly differ among habitat types, we found significantly higher species numbers in SWA than in wheat fields adjoining SWA and grassy margins when the number of recorded species was standardized to the number of individuals (rarefaction). Carabid assemblages in wheat fields differed from assemblages in adjoining SWA and grassy margins. The results of the present study emphasize the important contribution of semi‐natural habitats to diversify the spring carabid fauna in agroecosystems. In particular, SWA were shown to be useful to enhance carabid biodiversity conservation in agroecosystems, rather than to enhance their density‐dependent functions.

Impact of landscape improvement by agri-environment scheme options on densities of characteristic farmland bird species and brown hare (Lepus europaeus)

Causes for farmland bird declines are well studied, but on landscape level agri-environment schemes (AES) often show limited gains for biodiversity. We analysed population trends of nine farmland bird species and the brown hare in a Swiss arable landscape. Further, we focused on the impact of the quantity and quality of different ecological compensation area (ECA) options on densities of the study species, as well as on the extent of ECAs required on arable farmland to stop population declines of typical farmland species. Densities of bird species and hare counts were positively correlated with the quantity of ECAs and semi-natural habitat. However, effects of ECA options on birds and hares are species specific. The quantities of wildflower areas and semi-natural habitat strongly enhanced bird and hare numbers. The quality of the ECA options was also important, as densities were positively related to the amount of meadows of high ecological quality, but not to the amount of meadows of low ecological quality. To attain target densities, the required proportion of high-quality AES options and semi-natural habitat has to be at least 14%. This study provides evidence that intensively managed arable farmland can be improved for bird diversity and hare density by the Swiss AES. The amount of AES options of high ecological quality is of major relevance for nature conservation. We estimate that the amount of high-quality options and semi-natural habitats in the Swiss arable lowland must be four times higher than today's area to halt and reverse population declines of farmland species.

Habitat age affects beetle diversity in wildflower areas

Abundance, species richness, diversity and evenness of beetles inhabiting the vegetation layer in twenty 1–4 year old wildflower areas and winter wheat fields were compared to investigate the role of habitat age for biodiversity. Total beetle abundance and also abundance of economically important pest beetles decreased significantly with age of wildflower areas, showing that wildflower areas did not promote large populations with habitat age. Beetle species richness was significantly higher in 2–4 year old wildflower areas than in wheat. Diversity and evenness increased significantly with habitat age. Beetle species composition of wheat differed clearly from that in wildflower areas. Beetle assemblage was significantly associated with plant species richness, vegetation structure and plant biomass, accounting for 11.75, 10.73 and 9.71% of the total variance, respectively. It is therefore recommended to maintain a mosaic of wildflower areas of different age to conserve high beetle diversity in agroecosystems.