We investigate whether the eye parameter of bumblebees-a visual trait measuring the tradeoff between light sensitivity and visual resolution-is associated with: (i) local habitats, (ii) forest cover at the landscape scale (1 km radius), and (iii) the shade tolerance of the plants they forage on. The association of bumblebee species with local habitat and forest cover at the landscape scale was analyzed using generalized linear mixed models. We combined data from the Norwegian national bumblebee monitoring program with Corine CLC+ land cover and bumblebee functional traits: eye parameter and intertegular distance. These analyses were done at the species and community level. To determine whether bumblebee light sensitivity correlated with the shade tolerance of the plant they forage on, we combined bumblebee-plant interactions from a British database with a Swedish plant trait database. Our findings showed that bumblebee species with high light sensitivity were more common and abundant in forest habitats and areas with greater forest cover, while species with high visual resolution showed the opposite trend. This pattern was reflected at the community level, as indicated by the community-weighted mean of the eye parameter, which increased with forest cover and was higher in forest habitats. Furthermore, bumblebees with higher light sensitivity tended to forage on plants with greater shade tolerance. These results suggest that visual adaptations for light sensitivity contribute to shaping bumblebee species distributions across different scales. Our study underscores the importance of pollinator vision in understanding species niches and its value for species distribution modeling. Moreover, by relating pollinator visual abilities to plant niches for the first time, this study provides an important basis for future modeling of plant-pollinator interactions and targeted conservation measures for plants and pollinators in forested landscapes.

While functional traits like body size have been extensively linked to species distributions, the influence of sensory traits on species' responses to environmental changes remains underexplored. Particularly, the relationship between light sensitivity and niche segregation across different distributional extents - local habitat conditions and across entire landscapes - remains unclear. In this study, we examined bumblebee communities monitored across Norway on grassland and forest habitats within landscapes varying in forest cover within 1 km radii. We investigated whether the eye parameter - a visual trait measuring the trade-off between light sensitivity (high values) and visual resolution (low values) - was associated with local habitat types and the forest cover at the landscape scale. Additionally, we combined bumblebee-plant interactions with a plant trait, to determine if bumblebee light sensitivity correlated with the shade tolerance of the plants they foraged on. Our findings showed that bumblebee species with high eye parameters were more common and abundant in forest habitats and areas with greater forest cover, while species with low eye parameters showed the opposite trend. This pattern was also reflected at the community level, as indicated by the community-weighted mean of the eye parameter which increased with forest cover and was higher in forest habitats. Furthermore, bumblebees with higher eye parameters tended to forage on plants with greater shade tolerance. These results suggest that visual adaptations for light sensitivity contribute to shaping bumblebee species distributions across different scales. Overall, our study underscores the importance of pollinator vision in understanding species niches, in relation to habitat use and foraging behaviour. By relating pollinator visual abilities to plant niches for the first time, this study provides an important basis for future modelling of plant-pollinator interactions and targeted conservation measures for both plants and pollinators in forested landscapes. ### Competing Interest Statement The authors have declared no competing interest.

The ongoing biodiversity crisis is characterised not only by an elevated extinction rate but also can lead to an increasing similarity of species assemblages. This is an issue of major concern, as it can reduce ecosystem resilience and functionality. Changes in the composition of pollinator communities have mainly been described in intensive agricultural lowland areas. In this context, using a replicated survey of historical and recent bumblebee diversity, we aimed here to test how documented changes in climate and land use influenced the potential homogenization of sub-alpine bumblebee communities in southern Norway. We assessed the change in community composition in terms of taxonomic, phylogenetic and functional (β-)diversity, and estimated the impact of various species traits in probabilities of species gains and losses. Overall, we found a strong reduction in functional diversity, but no change in phylogenetic diversity over time. The β-diversity decreased, especially at high elevations, and this pattern was consistent for taxonomic, phylogenetic and functional β-diversity. The spatial distribution, measured as the average site occupancy, decreased in habitat-specialist species. This was explained by both a higher risk of species loss and a lower probability of species gain for habitat-specialist and parasitic species than for generalist and social species. These findings demonstrate that a narrow niche breadth may contribute to a higher extinction risk in bumblebee species. This non-random impact of disturbance on species may lead to large-scale biotic homogenisation of communities, a pattern that can be detected by investigating biodiversity changes at different scales and across its multiple facets.

1. Due to globalisation, trade and transport, the spread of alien species is increasing dramatically. Some alien species become ecologically harmful by threatening native biota. This can lead to irreversible changes in local biodiversity and ecosystem functioning, and, ultimately, to biotic homogenisation. 2. We risk-assessed all alien plants, animals, fungi and algae, within certain delimitations, that are known to reproduce in Norway. Mainland Norway and the Arctic archipelago of Svalbard plus Jan Mayen were treated as separate assessment areas. Assessments followed the Generic Ecological Impact Assessment of Alien Species (GEIAA) protocol, which uses a fully quantitative set of criteria. 3. A total of 1,519 species were risk-assessed, of which 1,183 were species reproducing in mainland Norway. Among these, 9% were assessed to have a severe impact, 7% high impact, 7% potentially high impact, and 49% low impact, whereas 29% had no known impact. In Svalbard, 16 alien species were reproducing, one of which with a severe impact. 4. The impact assessments also covered 319 so-called door-knockers, that is, species that are likely to establish in Norway within 50 years, and 12 regionally alien species. Of the door-knockers, 8% and 10% were assessed to have a severe and high impact, respectively. 5. The impact category of most species was driven by negative interactions with native species, transformation of threatened ecosystems, or genetic contamination. The proportion of alien species with high or severe impact varied significantly across the different pathways of introduction, taxonomic groups, time of introduction and the environments colonised, but not across continents of origin. 6. Given the large number of alien species reproducing in Norway and the preponderance of species with low impact, it is neither realistic nor necessary to eradicate all of them. Our results can guide management authorities in two ways. First, the use of quantitative assessment criteria facilitates the prioritisation of management resources across species. Second, the background information collected for each species, such as introduction pathways, area of occupancy and ecosystems affected, helps designing appropriate management measures.

Elinor M. Lichtenberg1,2*, Christina M. Kennedy3, Claire Kremen4, Péter Batáry5, Frank Berendse6, Riccardo Bommarco7, Nilsa A. Bosque-Pérez8, Luísa G. Carvalheiro9,10, William E. Snyder1, Neal M. Williams11, Rachael Winfree12, Björn Klatt5,13,14, Sandra Åström15, Faye Benjamin12, Claire Brittain11, Rebecca Chaplin-Kramer16, Yann Clough13, Heather Connelly17, Bryan Danforth17, Tim Diekötter18, Sanford D. Eigenbrode8, Johan Ekroos13, Elizabeth Elle19, Breno M. Freitas20, Yuki Fukuda21, Hannah R. Gaines-Day22, Claudio Gratton22, Andrea Holzschuh23, Rufus Isaacs24, Marco Isaia25, Shalene Jha26, Dennis Jonason27, Vincent P. Jones28, Alexandra-Maria Klein29, Jochen Krauss23, Deborah K. Letourneau30, Sarina Macfadyen31, Rachel E. Mallinger22, Emily A. Martin23, Eliana Martinez32, Jane Memmott33, Lora Morandin34, Lisa Neame35, Mark Otieno36, Mia G. Park17,37, Lukas Pfiffner38, Michael Pocock39, Carlos Ponce40, Simon G. Potts41, Katja Poveda17, Mariangie Ramos42, Jay A. Rosenheim11, Maj Rundlöf14, Hilary Sardiñas4, Manu E. Saunders43, Nicole L. Schon44, Amber R. Sciligo4, C. Sheena Sidhu45, Ingolf SteffanDewenter23, Teja Tscharntke5, Milan Veselý46, Wolfgang W. Weisser47, Julianna K. Wilson24, David W. Crowder1

We present the results of an inventory and status assessment of alien species in Norway. The inventory covered all known multicellular neobiota, 2496 in total, 1039 of which were classified as naturalised. The latter constitute c. 3% of all species known to be stably reproducing in Norway. These figures are higher than expected from Norway’s latitude, which may be due a combination of climatic and historical factors, as well as sampling effort. Most of the naturalised neobiota were plants (71%), followed by animals (21%) and fungi (8%). The main habitat types colonised were open lowlands (79%), urban environments (52%) and woodlands (42%). The main areas of origin were Europe (67%), North America (15%) and Asia (13%). For most taxa, the rate of novel introductions seems to have been increasing during recent decades. Within Norway, the number of alien species recorded per county was negatively correlated with latitude and positively correlated with human population density. In the high-Arctic territories under Norwegian sovereignty, i.e. Svalbard and Jan Mayen, 104 alien species were recorded, of which 5 were naturalised.

Climate and land-use change are recognised as the two main drivers of the ongoing reorganisation of Earth's biodiversity, but understanding precisely their role in shaping species' distributions and communities remains challenging. In mountainous regions, we typically observe an uphill shift of species' altitudinal ranges caused by increasing temperatures, but it is difficult to predict how this process interacts with land-use change. Here, we replicated an inventory of bumblebees that took place in the 1960s in Norway. Focusing on subalpine areas, we reported changes in species richness and community temperature index (CTI), a measure of the relative proportion of warm- and cold-adapted species, at low and high altitude. Using aerial photographs and meteorological data, we tested the relationship between climate and land-cover changes and changes in species richness and CTI. We observed an overall increase in CTI consistent with a gradual species turnover driven by climate change. There was on average an increase in species richness at high altitudes, while low-altitudes communities tendedto become less species-rich. Moreover, we observed a negative correlation between species richness and temperature and precipitation trends, suggesting a detrimental effect of climate change. Thanks to the replication of an historical inventory, we were able to show evidence for an effect of climate, and possibly land-cover, change on subalpine bumblebee assemblages. These results can contribute to a better understanding of the processes driving biodiversity changes in subalpine areas in a context of global climate and landscape changes.

Agricultural intensification is a leading cause of global biodiversity loss, which can reduce the provisioning of ecosystem services in managed ecosystems. Organic farming and plant diversification are farm management schemes that may mitigate potential ecological harm by increasing species richness and boosting related ecosystem services to agroecosystems. What remains unclear is the extent to which farm management schemes affect biodiversity components other than species richness, and whether impacts differ across spatial scales and landscape contexts. Using a global metadataset, we quantified the effects of organic farming and plant diversification on abundance, local diversity (communities within fields), and regional diversity (communities across fields) of arthropod pollinators, predators, herbivores, and detritivores. Both organic farming and higher in-field plant diversity enhanced arthropod abundance, particularly for rare taxa. This resulted in increased richness but decreased evenness. While these responses were stronger at local relative to regional scales, richness and abundance increased at both scales, and richness on farms embedded in complex relative to simple landscapes. Overall, both organic farming and in-field plant diversification exerted the strongest effects on pollinators and predators, suggesting these management schemes can facilitate ecosystem service providers without augmenting herbivore (pest) populations. Our results suggest that organic farming and plant diversification promote diverse arthropod metacommunities that may provide temporal and spatial stability of ecosystem service provisioning. Conserving diverse plant and arthropod communities in farming systems therefore requires sustainable practices that operate both within fields and across landscapes.

There is consensus that land-use change is a main driver behind the recent declines of many pollinator populations in Europe. However, it is still not adequately understood how the local resource quality and landscape composition influence pollinators, and if and how the effects vary in space and time. We analysed the influence of landscape- (2 km radius) and local scale- (50 m transects) resources on bumblebee species richness and abundance during two years in South-eastern Norway, where agriculture is highly modernised but landscapes still show limited spatial homogenization. Local flower density and species richness were strongly positively associated with bumblebee densities and species richness, but higher landscape-level flower species richness were linked to lower local bumblebee abundances. Early and late mass flowering crops had clear, but contrasting, effects. The total area of early flowering crops had a consistent negative impact on bumblebee density and species richness throughout the season, while late flowering crops had a positive impact in the beginning of the season before their bloom, suggesting a carry-over effect from previous years. The negative effects of early flowering crops could be due to competition of bumblebees with honey-bees, which are widely used in these crops. Bumblebee density and species richness were clearly negatively correlated with the total area of forest and flower-poor land use areas, including grass fields and cereals. In contrast, bumblebees were positively associated with most linear elements in the landscape (especially pasture and cropland verges), except for roads, which negatively affected bumblebee densities, possibly due to increased mortality, since the quality of the flower resources did not differ from other linear elements. Our results show that the quality and the spatial and temporal distribution of flower resources within the landscape are important drivers for bumblebees, but can create counterintuitive distribution patterns depending on the temporal and spatial resolution of the survey. Increasing flower resources in linear elements and the amount of late mass-flowering crops may be viable management measures to improve conditions for bumblebees in moderately intensified landscapes. (C) 2017 The Authors. Published by Elsevier B.V.

This report presents the sixth version of the European Grassland Butterfly Indicator, one of the EU biodiversity indicators of the European Environment Agency. The indicator is based on more than 9200 transects in national Butterfly Monitoring Schemes covering 22 countries across Europe, most of them active in the European Union. In 2015, counts were made in more than 4500 transects. Butterflies represent the largest animal group (insects), highly included in food webs, having a high impact on ecosystem services and stability. This report does not represent only the patrimonial conservation of some species, but indicates the changes in biodiversity on grasslands and discusses underlying causes. Fluctuations in numbers between years are typical features of butterfly populations. The assessment of change is therefore made on an analysis of the underlying trend. Indicators were produced on EU, European (EU plus Norway and Switzerland) and pan-European level (including Ukraine, Russia and Armenia). The underlying analysis of the indicator shows that since 1990, grassland butterfly abundance has declined by 30%. The rate of loss has slowed in the last 5-10 years. Part of this slowing down might be caused by climate warming, as this favours cold-blooded animals like butterflies, thus masking the effects of intensification. In parts of Western Europe butterfly numbers outside nature reserves have come to an absolute minimum, meaning it is unlikely for the indicator to further drop. The priority now is to halt further losses and support recovery. This can only come about with greater protection and more sustainable management of semi-natural grassland.

This report presents the fifth version of the European Grassland Butterfly Indicator, one of the EU biodiversity indicators of the European Environment Agency.

Increasing crop productivity to meet rising demands for food and energy, but doing so in an environmentally sustainable manner, is one of the greatest challenges for agriculture to date. In Ireland, Miscanthusxgiganteus has the potential to become a major feedstock for bioenergy production, but the economic feasibility of its cultivation depends on high yields. Miscanthus fields can have a large number of gaps in crop cover, adversely impacting yield and hence economic viability. Predominantly positive effects of Miscanthus on biodiversity reported from previous research might be attributable to high crop patchiness, particularly during the establishment phase. The aim of this research was to assess crop patchiness on a field scale and to analyse the relationship between Miscanthus yield and species richness and abundance of selected taxa of farmland wildlife. For 14 Miscanthus fields at the end of their establishment phase (4-5years after planting), which had been planted either on improved grassland (MG) or tilled arable land (MT), we determined patchiness of the crop cover, percentage light penetration (LP) to the lower canopy, Miscanthus shoot density and height, vascular plants and epigeic arthropods. Plant species richness and noncrop vegetation cover in Miscanthus fields increased with increasing patchiness, due to higher levels of LP to the lower canopy. The species richness of ground beetles and the activity density of spiders followed the increase in vegetation cover. Plant species richness and activity density of spiders on both MT and MG fields, as well as vegetation cover and activity density of ground beetles on MG fields, were negatively associated with Miscanthus yield. In conclusion, positive effects of Miscanthus on biodiversity can diminish with increasing productivity. This matter needs to be considered when assessing the relative ecological impacts of developing biomass crops in comparison with other land use.

Flea beetles, Phyllotreta Chevrolat (Coleoptera: Chrysomelidae) species, are often found in oilseed rape (OSR), Brassica napus Linnaeus (Brassicaceae). Among predators in the generalist predator complex present in agricultural fields, wolf spiders (Araneae: Lycosidae) are found on the ground and cobweb spiders (Araneae: Theridiidae) build webs in the foliage. We present group-specific primers developed for five flea beetle species within the genus Phyllotreta and study the incidence of predation of flea beetles by these spider groups using DNA-based gut-content analysis. Wolf spiders of the genus Pardosa Koch and the cobweb spider, Phylloneta impressa (Koch), were collected in three winter OSR fields. Flea beetle densities as well as the occurrence of predators and alternative prey were monitored. In total 19.4% of the collected Pardosa tested positive for flea beetle DNA in the polymerase chain reaction analyses, whereas 10% P. impressa were positive. Pardosa were more likely to be positive for flea beetle DNA when Pardosa activity density was low. Phylloneta impressa were more likely to be positive for flea beetle DNA if they were positive for pollen beetle DNA. Implications of these results for conservation biological control and future studies of food webs in OSR are discussed.