Climate and land-use changes are main drivers of insect declines, but their combined effects have not yet been quantified over large spatiotemporal scales. We analysed changes in the distribution ...(mean occupancy of squares) of 390 insect species (butterflies, grasshoppers, dragonflies), using 1.45 million records from across bioclimatic gradients of Switzerland between 1980 and 2020. We found no overall decline, but strong increases and decreases in the distributions of different species. For species that showed strongest increases (25% quantile), the average proportion of occupied squares increased in 40 years by 0.128 (95% credible interval: 0.123-0.132), which equals an average increase in mean occupancy of 71.3% (95% CI: 67.4-75.1%) relative to their 40-year mean occupancy. For species that showed strongest declines (25% quantile), the average proportion decreased by 0.0660 (95% CI: 0.0613-0.0709), equalling an average decrease in mean occupancy of 58.3% (95% CI: 52.2-64.4%). Decreases were strongest for narrow-ranged, specialised, and cold-adapted species. Short-term distribution changes were associated to both climate changes and regional land-use changes. Moreover, interactive effects between climate and regional land-use changes confirm that the various drivers of global change can have even greater impacts on biodiversity in combination than alone. In contrast, 40-year distribution changes were not clearly related to regional land-use changes, potentially reflecting mixed changes in local land use after 1980. Climate warming however was strongly linked to 40-year changes, indicating its key role in driving insect trends of temperate regions in recent decades.
•We map megatrends to gain foresight on the future of European agriculture.•Mapped megatrends are climate, demography, value system, and environmental regulation.•Different regions face pressures ...from different combinations of megatrends.•Regions range from highly susceptible to systemic change to highly persistent.•For sustainability transitions, megatrends inform what governance is needed.
A range of intensifying pressures is making the future of European agriculture dynamic and contested. Insights into these pressures are needed to inform debates about the future of the sector. In this study, we use a foresight approach to identify, quantify and map megatrends. Megatrends are long-term driving forces which are observable today and will likely have transformational potential in the future. By mapping these megatrends at the regional scale, we establish a geography of megatrends and detect where they coincide. Four megatrends significant for the future of European agriculture at the regional scale are assessed: Climate change, demographic change, (post-) productivism shifts, and increasingly stringent environmental regulations. The direction and intensity of these megatrends differs between regions, which drives regions into different systemic lock-ins or dynamics. In most regions, megatrends converge to destabilize the current system, forewarning impending systemic changes. While the specific megatrends contributing to this instability differ regionally, this result highlights that many regions are on a dynamic rather than stable trajectory, and the governance challenge is to steer these dynamics towards a desirable future. However, some regions are found to be highly persistent, indicating that megatrends reinforce business as usual, and change needs to be triggered through purposeful governance. In a minority of regions megatrends may drive marginalization as the current system becomes increasingly unviable. We argue that research and policies concerning agricultural sustainability transitions should be cognizant of the regional diversity of European megatrends and the pressures they create.
Continuous availability of food resources, such as pollen, is vital for many insects that provide pollination and pest control services to agriculture. However, there is a lack of knowledge about the ...shared or complementary use of floral resources by such species, which hampers more effective landscape management to simultaneously promote them in agroecosystems.
Here, we simultaneously quantified pollen use by a bumblebee (Bombus terrestris) and a mason bee (Osmia bicornis), two bee species recognized as important crop pollinators, as well as a lacewing (Chrysoperla carnea) and a ladybeetle species (Harmonia axyridis), both common predators of crop aphids, throughout the season in 23 agricultural landscapes in Germany and Switzerland.
Pollen diets were more diverse and similar among C. carnea and H. axyridis compared to the two bee species, but all four species shared key pollen types early in the season such as Acer, Quercus, Salix and Prunus. All species exhibited a pronounced shift in pollen sources from primarily woody plants (mainly trees) in spring to primarily herbaceous plants in summer. The majority of pollen (overall ≥64%) came from non‐agricultural plants even in crop‐dominated landscapes.
Synthesis and applications. Our results highlight the importance of trees as pollen sources for many insect species, particularly early in the season. Our findings support incentives that promote heterogeneous agricultural landscapes including both woody and herbaceous semi‐natural habitats, ensuring phenological complementarity of floral resources for insect species that can provide pollination and pest control services to agriculture. The identified key plant species can help to design and optimize agri‐environment schemes to promote these functionally important insects.
•Reproduction of two Osmia species increased with landscape-wide pollen availability.•Woody semi-natural habitats contributed disproportionately to the Osmia diet.•Benefits of forest proximity to ...Osmia indicated functions beyond pollen supply.•Resource and land cover maps help to understand the spatial ecology of wild bees.
Floral resources are crucial for wild pollinators. Identifying the spatio-temporal floral resource use of wild pollinators and effects of resource distribution on their development might help to promote them and their pollination services to crops in agricultural landscapes.
We established populations of Osmia cornuta and Osmia bicornis, two solitary wild bees, in 24 agricultural landscapes with varying floral resource availability. Based on their pollen use, we mapped the landscape-scale distribution of the visited plants, estimated pooled specific floral resource availabilities and measured its effects on reproductive output.
Woody semi-natural habitats such as hedgerows provided the majority of pollen sources for both Osmia species. Pollen use differed strongly between the two species. The offspring of both Osmia increased with availability of pooled specific pollen resources. In accordance with their preferred pollen types, offspring of O. cornuta increased with increasing cover of trees and shrubs of the Rosaceae family, and that of O. bicornis with increasing cover of Papaver rhoeas, Ranunculus acris and Quercus spp. as well as with the proximity to oilseed rape. In spite of their specific responses to pollen resources, the offspring of both species decreased with the distance to forest. The floral resource availability did not significantly affect the proportion of adult females and the weight of the offspring. As forest does not appear to be a main foraging habitat for both species, the benefit of forest proximity indicates an additional role of forest in addition to food availability.
Specific flowering plants and forests should thus be conserved and enhanced to maintain and support O. cornuta, O. bicornis and likely other wild bee populations in agricultural landscapes. The combined information of land cover and detailed floral resource availability gives a deeper understanding into population processes in agricultural landscapes.
Agroforestry, relative to conventional agriculture, contributes significantly to carbon sequestration, increases a range of regulating ecosystem services, and enhances biodiversity. Using a ...transdisciplinary approach, we combined scientific and technical knowledge to evaluate nine environmental pressures in terms of ecosystem services in European farmland and assessed the carbon storage potential of suitable agroforestry systems, proposed by regional experts. First, regions with potential environmental pressures were identified with respect to soil health (soil erosion by water and wind, low soil organic carbon), water quality (water pollution by nitrates, salinization by irrigation), areas affected by climate change (rising temperature), and by underprovision in biodiversity (pollination and pest control pressures, loss of soil biodiversity). The maps were overlaid to identify areas where several pressures accumulate. In total, 94.4% of farmlands suffer from at least one environmental pressure, pastures being less affected than arable lands. Regional hotspots were located in north-western France, Denmark, Central Spain, north and south-western Italy, Greece, and eastern Romania. The 10% of the area with the highest number of accumulated pressures were defined as Priority Areas, where the implementation of agroforestry could be particularly effective. In a second step, European agroforestry experts were asked to propose agroforestry practices suitable for the Priority Areas they were familiar with, and identified 64 different systems covering a wide range of practices. These ranged from hedgerows on field boundaries to fast growing coppices or scattered single tree systems. Third, for each proposed system, the carbon storage potential was assessed based on data from the literature and the results were scaled-up to the Priority Areas. As expected, given the wide range of agroforestry practices identified, the carbon sequestration potentials ranged between 0.09 and 7.29 t C ha−1 a−1. Implementing agroforestry on the Priority Areas could lead to a sequestration of 2.1 to 63.9 million t C a−1 (7.78 and 234.85 million t CO2eq a−1) depending on the type of agroforestry. This corresponds to between 1.4 and 43.4% of European agricultural greenhouse gas (GHG) emissions. Moreover, promoting agroforestry in the Priority Areas would contribute to mitigate the environmental pressures identified there. We conclude that the strategic and spatially targeted establishment of agroforestry systems could provide an effective means of meeting EU policy objectives on GHG emissions whilst providing a range of other important benefits.
•Patch LULC is the most important predictor of bird richness and abundance.•Woody structures increase bird richness, followed by extensive management.•Semi-natural structures and heterogeneity are ...beneficial on landscape-scale.•The effect of surrounding structure is only small, and interacts with patch LULC.
Agricultural intensification has profoundly changed agricultural landscapes with important biodiversity impacts. There is increasing knowledge on the general effects of landscape structure and management practices on plant and animal species but understanding the role of surrounding landscape structure for patch-scale biodiversity is more complex. While it can be reasonably assumed, that adjacent habitats are more important than more distant ones, the importance of landscape structure has often been tested at the landscape scale but rarely at smaller scales such as patch-surroundings. We assessed the influence and interdependences of landscape composition and configuration (LCC) and land use/land cover (LULC) on bird species richness and abundance through a multi-scale analysis with specific focus on the surrounding patches. In two agricultural regions in Switzerland, we collected point data of birds on 36 transects (500 m) and combined them with detailed spatial data on LULC. Bird richness and abundance were correlated to sets of landscape metrics as proxies for LCC computed at the transect-scale as well as for the patch surroundings. We analysed patch LULC as well as the most important patch-surrounding metrics using generalized linear mixed models. The results illustrate that patch LULC is the most important predictor of bird richness and abundance. Woody structures increase bird richness, followed by extensive management on patch scale. On the transect-scale semi-natural structure and heterogeneous LCCs are beneficial for bird richness and abundance. The effect of patch-surrounding structure LCCs is only small and interacts with patch LULC. Birds in grassland benefit from fallows in the surroundings, while in cropland they tend to respond positively to surrounding extensive grassland. Our results highlight that considering surroundings can help improve patch-based biodiversity assessments, which will then better predict the consequences of farmland management and make the outcome more applicable for practice.
1. Ecological theory predicts that the effectiveness of local agri-environmental management to enhance species richness at field scales will be the highest at intermediate levels of landscape ...complexity because of nonlinear effects of landscape context on field-scale diversity. 2. We examined how landscape complexity determined effectiveness of local agri-environmental management in terms of effects on species richness of birds, plants, spiders and bees in 232 extensive and intensive paired fields (112 arable fields and 120 grasslands) from 18 regions located in six European countries. 3. As predicted, landscape complexity enhanced field-scale species richness in a mostly nonlinear (sigmoidal) way, with earlier species richness increases in extensive than in intensive fields along landscape complexity gradients. Length of semi-natural boundaries (for arable fields) and proportion of unfarmed habitat (for grasslands) were the landscape features influencing species richness. 4. The relationships between effectiveness of local management and landscape complexity for all taxa were best described with hump-shaped curves, indicating the highest effectiveness at intermediate landscape complexities. 5. Synthesis and applications. We used models to investigate how and why effects of local management intensity on species richness vary along wide gradients of landscape complexity. We conclude that landscape-scale management options should take priority over local extensification measures within agri-environmental programmes. These programmes should follow a hierarchical multi-scale approach directed to address landscape-scale constraints on local diversity.
Aim: Species richness in itself is not always sufficient to evaluate land management strategies for nature conservation. The exchange of species between local communities may be affected by landscape ...structure and land-use intensity. Thus, species turnover, and its inverse, community similarity, may be useful measures of landscape integrity from a diversity perspective. Location: A European transect from France to Estonia. Methods: We measured the similarity of plant, bird, wild bee, true bug, carabid beetle, hoverfly and spider communities sampled along gradients in landscape composition (e.g. total availability of semi-natural habitat), landscape configuration (e.g. fragmentation) and land-use intensity (e.g. pesticide loads). Results: Total availability of semi-natural habitats had little effect on community similarity, except for bird communities, which were more homogeneous in more natural landscapes. Bee communities, in contrast, were less similar in landscapes with higher percentages of semi-natural habitats. Increased landscape fragmentation decreased similarity of true bug communities, while plant communities showed a nonlinear, U-shaped response. More intense land use, specifically increased pesticide burden, led to a homogenization of bee, bug and spider communities within sites. In these cases, habitat fragmentation interacted with pesticide load. Hoverfly and carabid beetle community similarity was differentially affected by higher pesticide levels: for carabid beetles similarity decreased, while for hoverflies we observed a U-shaped relationship. Main conclusions: Our study demonstrates the effects of landscape composition, configuration and land-use intensity on the similarity of communities. It indicates reduced exchange of species between communities in landscapes dominated by agricultural activities. Taxonomic groups differed in their responses to environmental drivers and using but one group as an indicator for 'biodiversity' as such would thus not be advisable.
Summer farms are seasonal enterprises in high-elevation mountain regions, established for and highly specialized in grazing ruminants. This article synthesizes studies by the Swiss AlpFUTUR research ...program on the profitability of and public financial support for summer farms. It highlights current challenges of Swiss pastoralism and makes recommendations for future reforms. Profitability hinges on the size of the summer farms as well as on their ability to create value added. Particularly for smaller summer farms, key value-added strategies appear to be innovative cheese production and effective direct marketing. Public financial support is substantial, and the underlying agri-environmental scheme is relatively sophisticated. Eligibility for public support is based on both action-oriented and results-oriented criteria. Direct payments consider not only the number of livestock but also the duration of their presence on the summer pastures. For each summer farm, a stocking target is defined based on the pasture's carrying capacity. However, this target does not take into account the wide variation in forage needs between different meat and milk production systems. During the last decade, there has been a decline in the number of cattle sent to summer farms. Understocking is widespread, and the abandonment of marginal pastures has increased, resulting in scrub encroachment. The remaining cattle tend to be concentrated on more productive surfaces to reduce management costs; this causes overgrazing. More attention should therefore be given to the accurate enforcement of agri-environmental standards and to regional-level agreement on which surfaces should be abandoned. Supporting traditional pastoral practices remains an explicit objective of Swiss agricultural policy. Recently introduced agri-environmental payment schemes promoting biodiversity conservation can complement the summer farm subsidies. However, implementation costs are likely to increase.
1. Increasing concern over the loss of biodiversity in agricultural landscapes was one of the reasons for the introduction of agri-environment schemes in Europe. These schemes compensate farmers ...financially for any loss of income associated with measures aimed to benefit biodiversity. Nevertheless, more than a decade after the introduction of the schemes, only a limited number of studies evaluating their ecological effects have been published. We assessed the effect of the Swiss agri-environment scheme that was designed to maintain and increase species richness in hay meadows. In Switzerland, hay meadows under this agri-environment scheme (ECA hay meadows) are the most widely adopted environmental measure to conserve biodiversity. 2. We tested whether meadows under the agri-environment scheme had higher species richness and species evenness than control meadows, whether species richness and species evenness were higher in the centre than at the edge of meadows, and whether these effects differed between geographical regions. 3. Biodiversity was sampled in 42 hay meadows in three different regions, using a pairwise comparison of ECA hay meadows with conventionally managed hay meadows. Biodiversity was estimated by assessing species richness and species evenness of four taxonomic groups representing different trophic levels: vascular plants, grasshoppers, wild bees and spiders. 4. Species richness of vascular plants, grasshoppers and wild bees was significantly higher on ECA hay meadows than on control meadows, but species richness of spiders did not differ. These results were consistent across the three study sites, except for the species richness of grasshoppers, which showed no difference between the ECA meadows and the control meadows in one region. 5. Species evenness was significantly higher on ECA hay meadows than on control meadows for plants and bees but not for spiders and grasshoppers. These results were consistent across the three study regions for bees and spider species only. 6. The species richness of vascular plants and spiders was higher at the edge than in the centre of both ECA and control meadows, suggesting a more extensive management in the meadow edges and a high species exchange between adjacent habitats for these two groups. 7. Synthesis and applications. We conclude that the Swiss agri-environment scheme for hay meadows positively affects biodiversity. The scheme should be maintained and farmers should be encouraged to engage in long-term extensive management. For spiders, the current management restrictions are not sufficient, most probably because of inappropriate vegetation structure. Therefore, organisms that particularly depend on vegetation structure should be targeted with additional restrictions: not only the time of the first cut but also the frequency of subsequent cuts and the mowing technique may have to be adjusted.
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