Quantifying potential trade-offs and win-wins between arthropod diversity and yield on cropland under agri-environment schemes-A meta-analysis

In Europe, agri-environment schemes (AES) are a key instrument to combat the ongoing decline of farmland biodiversity. AES aim is to support biodiversity and maintain ecosystem services, such as pollination or pest control. To what extent AES affect crop yield is still poorly understood. We performed a systematic review, including hierarchical meta-analyses, to investigate potential trade-offs and win-wins between the effectiveness of AES for arthropod diversity and agricultural yield on European croplands. Altogether, we found 26 studies with a total of 125 data points that fulfilled our study inclusion criteria. From each study, we extracted data on biodiversity (arthropod species richness and abundance) and yield for fields with AES management and control fields without AES. The majority of the studies reported significantly higher species richness and abundance of arthropods (especially wild pollinators) in fields with AES (31 % increase), but yields were at the same time significantly lower on fields with AES compared to control fields (21 % decrease). Aside from the opportunity costs, AES that promote out-of-production elements (e.g. wildflower strips), supported biodiversity (29-32 % increase) without significantly compromising yield (2-5 % increase). Farmers can get an even higher yield in these situations than in current conventional agricultural production systems without AES. Thus, our study is useful to identify AES demonstrating benefits for arthropod biodiversity with negligible or relatively low costs regarding yield losses. Further optimization of the design and management of AES is needed to improve their effectiveness in promoting both biodiversity and minimizing crop yield losses.

Farmland biodiversity monitoring through citizen science: A review of existing approaches and future opportunities

Biodiversity monitoring in agricultural landscapes is important for assessing the effects of both land use change and activities that influence farmland biodiversity. Despite a considerable increase in citizen science approaches to biodiversity monitoring in recent decades, their potential in farmland-specific contexts has not been systematically examined. This paper therefore provides a comprehensive review of existing citizen science approaches involving biodiversity monitoring on farmland. Using three complementary methods, we identify a range of programmes at least partially covering farmland. From these, we develop a typology of eight programme types, reflecting distinctions in types of data collected and nature of volunteer involvement, and highlight their respective strengths and limitations. While all eight types can make substantial contributions to farmland biodiversity monitoring, there is considerable scope for their further development-particularly through increased engagement of farmers, for whom receiving feedback on the effects of their own practices could help facilitate adaptive management.

AgroEcoList 1.0: A checklist to improve reporting standards in ecological research in agriculture

Many publications lack sufficient background information (e.g. location) to be interpreted, replicated, or reused for synthesis. This impedes scientific progress and the application of science to practice. Reporting guidelines (e.g. checklists) improve reporting standards. They have been widely taken up in the medical sciences, but not in ecological and agricultural research. Here, we use a community-centred approach to develop a reporting checklist (AgroEcoList 1.0) through surveys and workshops with 23 experts and the wider agroecological community. To put AgroEcoList in context, we also assessed the agroecological community's perception of reporting standards in agroecology. A total of 345 researchers, reviewers, and editors, responded to our survey. Although only 32% of respondents had prior knowledge of reporting guidelines, 76% of those that had said guidelines improved reporting standards. Overall, respondents agreed on the need of AgroEcolist 1.0; only 24% of respondents had used reporting guidelines before, but 78% indicated they would use AgroEcoList 1.0. We updated AgroecoList 1.0 based on respondents' feedback and user-testing. AgroecoList 1.0 consists of 42 variables in seven groups: experimental/sampling set-up, study site, soil, livestock management, crop and grassland management, outputs, and finances. It is presented here, and is also available on github (https://github.com/AgroecoList/Agroecolist). AgroEcoList 1.0 can serve as a guide for authors, reviewers, and editors to improve reporting standards in agricultural ecology. Our community-centred approach is a replicable method that could be adapted to develop reporting checklists in other fields. Reporting guidelines such as AgroEcoList can improve reporting standards and therefore the application of research to practice, and we recommend that they are adopted more widely in agriculture and ecology.

Land sharing complements land sparing in the conservation of disturbance-dependent species

Alteration of natural disturbances in human-modified landscapes has resulted in many disturbance-dependent species becoming rare. Conservation of such species requires efforts to maintain or recreate disturbance regimes. We compared benefits of confining efforts to habitats in protected areas (a form of land sparing) versus integrating them with general management of production land (a form of land sharing), using two examples: fire in forests and grazing in semi-natural grasslands. We reviewed empirical studies from the temperate northern hemisphere assessing effects of disturbances in protected and non-protected areas, and compiled information from organisations governing and implementing disturbances in Sweden. We found advantages with protection of areas related to temporal continuity and quality of disturbances, but the spatial extent of disturbances is higher on production land. This suggests that an approach where land sparing is complemented with land sharing will be most effective for preservation of disturbance-dependent species in forests and semi-natural grasslands.

Protected area designation and management in a world of climate change: A review of recommendations

Climate change is challenging conservation strategies for protected areas. To summarise current guidance, we systematically compiled recommendations from reviews of scientific literature (74 reviews fitting inclusion criteria) about how to adapt conservation strategies in the face of climate change. We focussed on strategies for designation and management of protected areas in terrestrial landscapes, in boreal and temperate regions. Most recommendations belonged to one of five dominating categories: (i) Ensure sufficient connectivity; (ii) Protect climate refugia; (iii) Protect a few large rather than many small areas; (iv) Protect areas predicted to become important for biodiversity in the future; and (v) Complement permanently protected areas with temporary protection. The uncertainties and risks caused by climate change imply that additional conservation efforts are necessary to reach conservation goals. To protect biodiversity in the future, traditional biodiversity conservation strategies should be combined with strategies purposely developed in response to a warming climate.

Showcasing synergies between agriculture, biodiversity and ecosystem services to help farmers capitalising on native biodiversity (SHOWCASE)

The slow adoption by the agricultural sector of practices to promote biodiversity are thought to originate from three interrelated issues. First, we know little about which incentives effectively motivate farmers to integrate biodiversity into daily farm management. Second, few studies so far have produced evidence that biodiversity-based approaches produce benefits in terms of key variables for farmers (yield, profit). Third, there is a large communication gap between the scientists investigating biodiversity-based farming practices and the farmers who have to implement them. To overcome these barriers, SHOWCASE will review and test the effectiveness of a range of economic and societal incentives to implement biodiversity management in farming operations and examine farmer and public acceptance. Focus will be on three promising approaches: (i) result-based incentives, (ii) involvement in citizen science biodiversity monitoring and (iii) biodiversity-based business models. SHOWCASE will co-produce together with stakeholders solid interdisciplinary evidence for the agro-ecological and socio-economic benefits of biodiversity management in 10 contrasting farming systems across Europe. SHOWCASE will also design communication strategies that are tailor-made to farmers and other key stakeholders operating in different socio-economic and environmental conditions.

SHOWCASE will develop a multi-actor network of 10 Experimental Biodiversity Areas in contrasting European farming systems that will be used for in-situ research on biodiversity incentives and evidence for benefits as well as knowledge exchange. This network will be used to identify and test biodiversity indicators and targets relevant to all stakeholders and use them in a learning-by-doing approach to improve benefits of biodiversity management on farms, both within the network and beyond.

Operationalisation of ecological compensation - Obstacles and ways forward

Ecological compensation (EC) has been proposed as an important tool for stopping the loss of biodiversity and natural values. However, there are few studies on its actual operationalisation and there is high uncertainty about how it should be designed and implemented to be an effective way of performing nature conservation. In this study we focus on ecological compensation in Sweden, a country where it is in the process of being implemented more broadly. Using interviews and a workshop we investigate how the work with the implementation is carried out and what challenges exist. The results show that implementation of EC is at an early stage of development and there are many practical obstacles, linked to both legislation and routines in the planning processes. There is a lack of holistic perspective and large-scale thinking, a quite strong focus on a small number of individual species, and an overall attitude that anything is better than nothing, all of which can have negative consequences for biodiversity conservation overall. Based on the results we discuss the need for better integration of EC into the entire decision-making process and for a holistic approach to preservation of biodiversity and ecosystem services, by increasing the focus on landscape perspective and considering delays in compensation outcomes. There is also a need for a national level standard for EC, making good and worse examples of compensation measures available and systematic monitoring of EC projects. Finally, a spatially explicit database to document all EC areas should be introduced both to ensure consistency in protection from future development plans and to enable long-term monitoring of EC outcomes.

Can field botany be effectively taught as a distance course? Experiences and reflections from the COVID-19 pandemic

The COVID-19 pandemic that started in 2020 forced a rapid change in university teaching, with large numbers of courses switching to distance learning with very little time for preparation. Courses involving many practical elements and field excursions required particular care if students were to fulfil planned learning outcomes. Here, we present our experiences in teaching field botany in 2020 and 2021. Using a range of methods and tools to introduce students to the subject, promote self-learning and reflection and give rapid and regular feedback, we were able to produce a course that allowed students to achieve the intended learning outcomes and that obtained similarly positive student evaluations to previous years. The course and its outcomes were further improved in 2021. We describe how we structured field botany as a distance course in order that we could give the best possible learning experience for the students. Finally, we reflect on how digital tools can aid teaching such subjects in the future, in a world where public knowledge of natural history is declining.

Decline of parasitic and habitat-specialist species drives taxonomic, phylogenetic and functional homogenization of sub-alpine bumblebee communities

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.

Habitat amount and distribution modify community dynamics under climate change

Habitat fragmentation may present a major impediment to species range shifts caused by climate change, but how it affects local community dynamics in a changing climate has so far not been adequately investigated empirically. Using long-term monitoring data of butterfly assemblages, we tested the effects of the amount and distribution of semi-natural habitat (SNH), moderated by species traits, on climate-driven species turnover. We found that spatially dispersed SNH favoured the colonisation of warm-adapted and mobile species. In contrast, extinction risk of cold-adapted species increased in dispersed (as opposed to aggregated) habitats and when the amount of SNH was low. Strengthening habitat networks by maintaining or creating stepping-stone patches could thus allow warm-adapted species to expand their range, while increasing the area of natural habitat and its spatial cohesion may be important to aid the local persistence of species threatened by a warming climate.

Temperature drives abundance fluctuations, but spatial dynamics is constrained by landscape configuration: Implications for climate-driven range shift in a butterfly

Prediction of species distributions in an altered climate requires knowledge on how global- and local-scale factors interact to limit their current distributions. Such knowledge can be gained through studies of spatial population dynamics at climatic range margins. Here, using a butterfly (Pyrgus armoricanus) as model species, we first predicted based on species distribution modelling that its climatically suitable habitats currently extend north of its realized range. Projecting the model into scenarios of future climate, we showed that the distribution of climatically suitable habitats may shift northward by an additional 400 km in the future. Second, we used a 13-year monitoring dataset including the majority of all habitat patches at the species northern range margin to assess the synergetic impact of temperature fluctuations and spatial distribution of habitat, microclimatic conditions and habitat quality, on abundance and colonization-extinction dynamics. The fluctuation in abundance between years was almost entirely determined by the variation in temperature during the species larval development. In contrast, colonization and extinction dynamics were better explained by patch area, between-patch connectivity and host plant density. This suggests that the response of the species to future climate change may be limited by future land use and how its host plants respond to climate change. It is, thus, probable that dispersal limitation will prevent P. armoricanus from reaching its potential future distribution. We argue that models of range dynamics should consider the factors influencing metapopulation dynamics, especially at the range edges, and not only broad-scale climate. It includes factors acting at the scale of habitat patches such as habitat quality and microclimate and landscape-scale factors such as the spatial configuration of potentially suitable patches. Knowledge of population dynamics under various environmental conditions, and the incorporation of realistic scenarios of future land use, appears essential to provide predictions useful for actions mitigating the negative effects of climate change.

Landscape simplification weakens the association between terrestrial producer and consumer diversity in Europe

Land-use change is one of the primary drivers of species loss, yet little is known about its effect on other components of biodiversity that may be at risk. Here, we ask whether, and to what extent, landscape simplification, measured as the percentage of arable land in the landscape, disrupts the functional and phylogenetic association between primary producers and consumers. Across seven European regions, we inferred the potential associations (functional and phylogenetic) between host plants and butterflies in 561 seminatural grasslands. Local plant diversity showed a strong bottom-up effect on butterfly diversity in the most complex landscapes, but this effect disappeared in simple landscapes. The functional associations between plant and butterflies are, therefore, the results of processes that act not only locally but are also dependent on the surrounding landscape context. Similarly, landscape simplification reduced the phylogenetic congruence among host plants and butterflies indicating that closely related butterflies become more generalist in the resources used. These processes occurred without any detectable change in species richness of plants or butterflies along the gradient of arable land. The structural properties of ecosystems are experiencing substantial erosion, with potentially pervasive effects on ecosystem functions and future evolutionary trajectories. Loss of interacting species might trigger cascading extinction events and reduce the stability of trophic interactions, as well as influence the longer term resilience of ecosystem functions. This underscores a growing realization that species richness is a crude and insensitive metric and that both functional and phylogenetic associations, measured across multiple trophic levels, are likely to provide additional and deeper insights into the resilience of ecosystems and the functions they provide.

Sustained functional composition of pollinators in restored pastures despite slow functional restoration of plants

Habitat restoration is a key measure to counteract negative impacts on biodiversity from habitat loss and fragmentation. To assess success in restoring not only biodiversity, but also functionality of communities, we should take into account the re-assembly of species trait composition across taxa. Attaining such functional restoration would depend on the landscape context, vegetation structure, and time since restoration. We assessed how trait composition of plant and pollinator (bee and hoverfly) communities differ between abandoned, restored (formerly abandoned) or continuously grazed (intact) semi-natural pastures. In restored pastures, we also explored trait composition in relation to landscape context, vegetation structure, and pasture management history. Abandoned pastures differed from intact and restored pastures in trait composition of plant communities, and as expected, had lower abundances of species with traits associated with grazing adaptations. Further, plant trait composition in restored pastures became increasingly similar to that in intact pastures with increasing time since restoration. On the contrary, the trait composition of pollinator communities in both abandoned and restored pastures remained similar to intact pastures. The trait composition for both bees and hoverflies was influenced by flower abundance and, for bees, by connectivity to other intact grasslands in the landscape. The divergent responses across organism groups appeared to be mainly related to the limited dispersal ability and long individual life span in plants, the high mobility of pollinators, and the dependency of semi-natural habitat for bees. Our results, encompassing restoration effects on trait composition for multiple taxa along a gradient in both time (time since restoration) and space (connectivity), reveal how interacting communities of plants and pollinators are shaped by different trait-environmental relationships. Complete functional restoration of pastures needs for more detailed assessments of both plants dispersal in time and of resources available within pollinator dispersal range.

Host plant density and patch isolation drive occupancy and abundance at a butterfly's northern range margin

Marginal populations are usually small, fragmented, and vulnerable to extinction, which makes them particularly interesting from a conservation point of view. They are also the starting point of range shifts that result from climate change, through a process involving colonization of newly suitable sites at the cool margin of species distributions. Hence, understanding the processes that drive demography and distribution at high-latitude populations is essential to forecast the response of species to global changes. We investigated the relative importance of solar irradiance (as a proxy for microclimate), habitat quality, and connectivity on occupancy, abundance, and population stability at the northern range margin of the Oberthür's grizzled skipper butterfly Pyrgus armoricanus. For this purpose, butterfly abundance was surveyed in a habitat network consisting of 50 habitat patches over 12 years. We found that occupancy and abundance (average and variability) were mostly influenced by the density of host plants and the spatial isolation of patches, while solar irradiance and grazing frequency had only an effect on patch occupancy. Knowing that the distribution of host plants extends further north, we hypothesize that the actual variable limiting the northern distribution of P. armoricanus might be its dispersal capacity that prevents it from reaching more northern habitat patches. The persistence of this metapopulation in the face of global changes will thus be fundamentally linked to the maintenance of an efficient network of habitats.

Predicting bee community responses to land-use changes: Effects of geographic and taxonomic biases

Land-use change and intensification threaten bee populations worldwide, imperilling pollination services. Global models are needed to better characterise, project, and mitigate bees' responses to these human impacts. The available data are, however, geographically and taxonomically unrepresentative; most data are from North America and Western Europe, overrepresenting bumblebees and raising concerns that model results may not be generalizable to other regions and taxa. To assess whether the geographic and taxonomic biases of data could undermine effectiveness of models for conservation policy, we have collated from the published literature a global dataset of bee diversity at sites facing land-use change and intensification, and assess whether bee responses to these pressures vary across 11 regions (Western, Northern, Eastern and Southern Europe; North, Central and South America; Australia and New Zealand; South East Asia; Middle and Southern Africa) and between bumblebees and other bees. Our analyses highlight strong regionally-based responses of total abundance, species richness and Simpson's diversity to land use, caused by variation in the sensitivity of species and potentially in the nature of threats. These results suggest that global extrapolation of models based on geographically and taxonomically restricted data may underestimate the true uncertainty, increasing the risk of ecological surprises.

The role of biotic interactions in shaping distributions and realised assemblages of species: implications for species distribution modelling

Predicting which species will occur together in the future, and where, remains one of the greatest challenges in ecology, and requires a sound understanding of how the abiotic and biotic environments interact with dispersal processes and history across scales. Biotic interactions and their dynamics influence species' relationships to climate, and this also has important implications for predicting future distributions of species. It is already well accepted that biotic interactions shape species' spatial distributions at local spatial extents, but the role of these interactions beyond local extents (e.g. 10 km(2) to global extents) are usually dismissed as unimportant. In this review we consolidate evidence for how biotic interactions shape species distributions beyond local extents and review methods for integrating biotic interactions into species distribution modelling tools. Drawing upon evidence from contemporary and palaeoecological studies of individual species ranges, functional groups, and species richness patterns, we show that biotic interactions have clearly left their mark on species distributions and realised assemblages of species across all spatial extents. We demonstrate this with examples from within and across trophic groups. A range of species distribution modelling tools is available to quantify species environmental relationships and predict species occurrence, such as: (i) integrating pairwise dependencies, (ii) using integrative predictors, and (iii) hybridising species distribution models (SDMs) with dynamic models. These methods have typically only been applied to interacting pairs of species at a single time, require a priori ecological knowledge about which species interact, and due to data paucity must assume that biotic interactions are constant in space and time. To better inform the future development of these models across spatial scales, we call for accelerated collection of spatially and temporally explicit species data. Ideally, these data should be sampled to reflect variation in the underlying environment across large spatial extents, and at fine spatial resolution. Simplified ecosystems where there are relatively few interacting species and sometimes a wealth of existing ecosystem monitoring data (e.g. arctic, alpine or island habitats) offer settings where the development of modelling tools that account for biotic interactions may be less difficult than elsewhere.

Landscape structure shapes habitat finding ability in a butterfly

Land-use intensification and habitat fragmentation is predicted to impact on the search strategies animals use to find habitat. We compared the habitat finding ability between populations of the speckled wood butterfly (Pararge aegeria L.) from landscapes that differ in degree of habitat fragmentation. Naïve butterflies reared under standardized laboratory conditions but originating from either fragmented agricultural landscapes or more continuous forested landscapes were released in the field, at fixed distances from a target habitat patch, and their flight paths were recorded. Butterflies originating from fragmented agricultural landscapes were better able to find a woodlot habitat from a distance compared to conspecifics from continuous forested landscapes. To manipulate the access to olfactory information, a subset of individuals from both landscape types were included in an antennae removal experiment. This confirmed the longer perceptual range for butterflies from agricultural landscapes and indicated the significance of both visual and olfactory information for orientation towards habitat. Our results are consistent with selection for increased perceptual range in fragmented landscapes to reduce dispersal costs. An increased perceptual range will alter the functional connectivity and thereby the chances for population persistence for the same level of structural connectivity in a fragmented landscape.