The decline of pollinators in agricultural environments poses a significant threat to pollination ecosystem services. Wildflower strips are proposed as a strategy to support pollinator populations and enhance their species richness and diversity. We investigated the efficacy of flowering plant mixture in maintaining aculeate pollinator diversity (wild bees, predatory wasps, and their kleptoparasites) within intensively managed agricultural environments where rapeseed is a common rotational crop. Over four years, pollinators were counted five times per season using 250 m transect walks. Our results demonstrated that the diversity and the evenness of species abundance distribution of aculeate pollinators were higher in the sown wildflower strips, whereas mean abundance per transect was greater in the remnants of semi-natural grassland. The low diversity and evenness within the aculeate pollinator assemblage of the semi-natural habitat were attributed to the dominance of the sweat bee <i>Lasioglossum pauxillum</i>, which thrived on mass-flowering rapeseed and concentrated in the flowering grassland fragments after the rapeseed harvest. We conclude that wildflower strips enriched with sown flowering plant mixtures effectively enhance pollinator diversity. Furthermore, both wildflower strips and preserved patches of unmanaged or minimally managed semi-natural grassland habitats can essentially contribute to maintaining pollination ecosystem services within intensive agricultural environments.

The decline of pollinators in agricultural environments poses a significant threat to pollination ecosystem services. Wildflower strips are proposed as a strategy to support pollinator populations and enhance their species richness and diversity. We investigated the efficacy of flowering plant mixture in maintaining aculeate pollinator diversity (wild bees, predatory wasps, and their kleptoparasites) within intensively managed agricultural environments where rapeseed is a common rotational crop. Over four years, pollinators were counted five times per season using 250 m transect walks. Our results demonstrated that the diversity and the evenness of species abundance distribution of aculeate pollinators were higher in the sown wildflower strips, whereas mean abundance per transect was greater in the remnants of semi-natural grassland. The low diversity and evenness within the aculeate pollinator assemblage of the semi-natural habitat were attributed to the dominance of the sweat bee Lasioglossum pauxillum, which thrived on mass-flowering rapeseed and concentrated in the flowering grassland fragments after the rapeseed harvest. We conclude that wildflower strips enriched with sown flowering plant mixtures effectively enhance pollinator diversity. Furthermore, both wildflower strips and preserved patches of unmanaged or minimally managed semi-natural grassland habitats can essentially contribute to maintaining pollination ecosystem services within intensive agricultural environments.

Context: Intensive agriculture drives insect decline impacting insect-mediated ecosystem services that support production. Crop diversification shows promise in increasing crop productivity and enhancing ecosystem services, however, the impact on biodiversity conservation, particularly of pollinators, is unclear. Objectives: Here, we synthesize the mechanisms and current evidence base of how increasing the spatial and temporal diversity of crops within and across agricultural fields can benefit pollinator biodiversity. Methods: We focus on research in the highly intensified agricultural regions, in Western Europe and North America, from which we know a lot about pollinator decline, but use inspiration from tropical regions. Results: We find that higher crop diversity, with sequentially flowering cultivars, intercropping practices, and a larger coverage of flowering crops, for example through integrating the cultivation of forgotten, novel, and woody crops increases flower resource availability throughout the active flight period of pollinators. All practices can increase landscape heterogeneity, which is further enhanced by decreasing field sizes. As a result, the functional connectivity increases, which improves the flower accessibility within the foraging ranges of pollinators. Conclusions: Our review highlights the potential benefit of various crop diversification measures for supporting pollinating insects without taking land out of production, as well as the limitations, including that only a subset of pollinator species may benefit. Empirical evidence suggest that diversification practices could benefit pollinators, but landscape-wide studies are needed to properly evaluate the true potential of crop diversification for pollinator conservation as part of the solution for bending the curve of pollinator decline.

Insect-plant interactions are key determinants of plant and insect fitness, providing important ecosystem services around the world-including the Arctic region. Recently, it has been suggested that climate warming causes rifts between flower and pollinator phenology. To what extent the progression of pollinators matches the availability of flowers in the Arctic season is poorly known. In this study, we aimed to characterize the community phenology of flowers and insects in a rapidly changing Arctic environment from a descriptive and functional perspective. To this end, we inferred changes in resource availability from both a plant and an insect point of view, by connecting resource and consumer species through a metaweb of all the plant-insect interactions ever observed at a site. Specifically, we: (1) characterized species-specific phenology among plants and insects at two High-Arctic sites-Cambridge Bay in Nunavut, Canada, and Zackenberg in Northeast Greenland; (2) quantified competition for flowers using sticky flower mimics; (3) used information on plant-pollinator interactions to quantify supply and demand for pollinator services versus flower resources during the summer; and (4) compared patterns observed within a focal summer at each site to patterns of long-term change at Zackenberg, using a 25-year time series of plant flowering and insect phenology. Within summers, we found evidence of a general mismatch between supply and demand. Over the 25-year time series, the number of weeks per summer when resource supply fell below a standardized threshold increased significantly over time. In addition, variation in resource availability increased significantly over years. We suggest that the number of resource-poor weeks per year is increasing and becoming less predictable in the High Arctic. This will have important implications for plant pollination, pollinator fitness, and the future of the Arctic ecosystem, as both plants and their pollinators are faced with widening resource gaps.

The boreal forest, one of the world's largest terrestrial biomes, is currently experiencing rapid climate-driven changes. This review synthesizes the limited research available on climate-change impacts on boreal plantpollinator systems, revealing several knowledge gaps and shedding light on the vulnerabilities of boreal ecosystems. Using four complementary Web of Science searches, we found 5198 articles, of which only 11 were relevant. Our findings reveal that research on boreal plant-pollinator interactions is limited to date, as is our understanding of the insect fauna and pollination systems in the boreal region. Existing research often focuses on conspicuous plants, neglecting many other ecologically significant species. In addition, current studies often lack detailed data on pollinator species, which restricts our capacity to assess the vulnerability of specific plantpollinator interactions to climate change. For example, most articles use plant reproductive success as a proxy for pollinator effectiveness without considering pollinator identity. This approach successfully assesses overall plant fitness, but overlooks changes to pollinator communities, such as those resulting from thermophilization, that may be relevant to projecting climate-change impacts. Moreover, pollinator taxon seems to affect the responses of plant reproduction to warming, with fly-pollinated plants appearing to be more resilient to temperature changes than bee-pollinated plants. Future research should prioritize foundational plant species and key pollinators, including flies, which are crucial to boreal pollination ecology. Understanding species-specific responses to warming is equally important for identifying which species and interactions may be most vulnerable to climate change. Studies should also examine the role of forest microclimates, as they may buffer boreal regions during broader climatic shifts, helping to mitigate the impacts of warming on these ecosystems. Addressing these gaps is essential for predicting climate impacts on boreal biodiversity and for informing conservation strategies that support biodiversity and benefit human communities reliant on boreal ecosystem services.

Despite the widely recognized role of pollinators in ecosystem services, we currently have a poor understanding of the contribution of Natural Protected Areas neighboring agricultural landscapes to crop pollinator diversity and plant-pollinator interactions. Here, we conducted monthly surveys over a period of one year to study the diversity of insect visitors in dominant fruit crops—avocado, plum, apple, and blackberry—and used pollen DNA metabarcoding to characterize the community of plant sources in and around low-intensive farmland bordered by protected montane forest in Costa Rica. We found that crops and native plants had distinct communities of flower visitors, suggesting the presence of fine-scale habitat differences. DNA metabarcoding coupled with a custom-built reference database, enabled us to identify plant sources among pollen samples with high taxonomic resolution (species or genus level). We found that insect visitors carried pollen from a large diversity of plant taxa, including species native to the montane forests and highland páramos of Costa Rica. The diversity and composition of plant sources were variable across fruit crops and insect groups. Wildflower visitors such as bumblebees and syrphid flies, use a diverse range of plant taxa at similar levels to managed honeybees. This indicates the potential contribution of a diverse community of insect visitors to the pollination services of fruit crops and native flora. Overall, our study suggests that low-intensive farming practices that promote the presence of common ruderals combined with nearby protected forests contribute to maintaining diverse insect communities that provide crucial pollination services.

The interactions between plants and their pollinators provide essential ecosystem services in support of the reproduction and propagation of flowering plants, as well as the nutritive support for pollinators and their offspring.  Given the critical nature of these activities, coupled with exponential urban development and the concurrent, dramatic decline in pollinators worldwide, it has become increasingly important to evaluate the complex and specialized interactions between pollinators and their host plants.  This includes assessing plant-pollinator interactions within urban green infrastructure.  Here, we surveyed floral visitor interactions on nineteen summer-blooming plant species in two contiguous Richmond, Virginia, gardens.  We observed 110 distinct flower visitor taxa, with the majority seen on four or fewer plant species.  The most common flower visitors were bees, including Bombus impatiens, which was found on every plant surveyed.  Although the flower visitor assemblages varied categorically among plant species, in total the two gardens hosted a broad range of generalist and specialist visitors.  The results of this survey provide a regional and seasonal perspective on urban green space ecosystem dynamics.

As core constituents of healthy diets, fruits are often cultivated in temporally stable and structurally complex ecosystems that harbor high levels of biodiversity. However, high-intensity orchard management can lessen the human and environmental health benefits of fruticulture. In the present article, we argue that increased emphasis on biological control could contribute to preventative manage- ment of fruit pests, weeds, and diseases, resulting in pesticide phasedown. Carefully calibrated orchard management can increase the provision of ecosystem services by above- and belowground biota, improve soil health, and store atmospheric carbon. When tactically integrated with agroecological measures, behavior-modifying chemicals, or digital tools, biological control helps to conserve pollinator or soil fauna, protect vertebrate communities, and improve vegetation restoration outcomes. Its implementation can, however, give rise to scientific and social challenges that will need to be explored. By resolving the adoption hurdles for biological control at scale, human society could enjoy the myriad benefits of nature-friendly fruit production

Afforestation of abandoned grasslands has been proposed as a global climate mitigation strategy, but the climate benefits of tree planting on grasslands remain contentious. Studies worldwide indicate that grassland soils have large potential for carbon storage, while semi-natural grasslands often support high biodiversity and provide multiple ecosystem services, including grazing resources, pollinator habitats, and aesthetic landscape values. In boreal and alpine regions of the Nordic countries, grasslands sustain extensive low intensity farming, contributing to milk and meat production and enhancing food self-sufficiency. Evaluating the impact of afforestation on climate mitigation requires a comprehensive assessment that, in addition to the carbon balance, considers both geophysical forcing (such as albedo and evapotranspiration) and the broader landscape-level effects on biodiversity in displaced ecosystems. The article postulates for policy to be inclusive of both biodiversity preservation and climate change mitigation. Such an approach should be grounded in evidence-based assessments of the ecological and climate-related impacts of afforestation on the biodiversity of semi-natural grasslands.

Green roofs provide vital functions within the urban ecosystem, from supporting biodiversity, to sustainable climate-positive ESS provisioning. However, how plant communities should best be designed to reach these objectives, and how specific green roof systems vary in their capacity to support these functions is not well understood. Here we compiled data on plant traits and plant–insect interaction networks of a regional calcareous grassland species pool to explore how designed plant communities could be optimised to contribute to ecological functionality for predefined green roof solutions. Five distinct systems with practical functionality and physical constraints were designed, plant communities modelled using object-based optimization algorithms and evaluated using five ecological functionality metrics (incl. phylogenetic and structural diversity). Our system plant communities supported a range of plant–insect interactions on green roofs, but not all species were equally beneficial, resulting in wide-ranging essentiality and redundancy in ecological processes. Floral traits were not predictive of pollinator preferences, but phylogeny was observed to govern the preferences. Large differences in ecological functionality can be expected between green roofs depending on system design and the extent of the plant community composition. Multifunctionality covariance diverged between systems, suggesting that ecological functionality is not inherently universal but dependent on structural limitations and species pool interactions. We conclude that informed system design has a potential to simultaneously support ecosystem services and urban biodiversity conservation by optimising green roof plant communities to provide landscape resources for pollinating insects and herbivores. | publishedVersion