These results indicate that floral plantings have great potential to benefit ecosystem service provision, but to do so will need to be carefully tailored for functioning at specific spatial scales. Flower diversity and strip age are important drivers through which this can be achieved and they should be considered integrally before floral plantings can make a significant contribution to the ecological intensification of agricultural production. We found positive effects of flower strips on ecosystem service provisioning in support of the ‘exporter’ hypothesis , although effects were generally variable and only significant for flower strips enhancing pest control services by 16% on average. This is an important finding as it provides general empirical evidence that flower strips can reduce crop pest pressures across various crops, landscape contexts and geographical regions. One explanation for the more consistent positive effects on pest control services of flower strips compared to hedgerows may be that in many of the studied flower strips the selection of flowering plants was tailored to the requirements of the target natural enemy taxa while this was generally less the case in the studied hedgerow plantings. Wildflower plantings have been heralded as one of the most effective measures to enhance the provision of ecosystem service to crops with many studies showing positive effects on service provisioning .
Our synthesis shows, however, hydroponic channel that although general significant effects of flower strips were found for pest control service provisioning, effects of plantings on crop pollination services were highly variable. This highlights the need to better understand these conditions and drivers of success or failure of floral plantings to promote pollination services. Our synthesis identifies several drivers explaining this variability in delivered services and therefore offers pathways to enhance the effectiveness of these measures in the future. First, the success of flower strips to promote crop pollination services increased with their age. Pollination services also appeared to continue to increase with establishment time beyond three years. This trend needs to be interpreted with caution as only three studies assessed four years old or older flower strips highlighting that scarcity of long-term data on the effects of floral plantings on services provisioning and yield, which represents an important knowledge gap. We found no evidence that this increase in effectiveness with age is driven by floral abundance, as flower abundance did not increase with flower strip age. Case studies from Central and Northwestern Europe suggest that abundance and species richness of flowering herbaceous plants in sown flower strips on the highly fertilised soils in these agricultural regions often even decline with age after the second or third year as grasses take over . The observed positive effect of flower strip age is, however, in agreement with the expectation that the build-up and restoration of local crop pollinator populations need time . It may also be explained by greater provision of nesting and overwintering opportunities in older floral plantings which are likely scarce in short-lived annual flower strips that could even be ecological traps for overwintering arthropods .
In fact, Kremen and M’Gonigle found higher incidence of above-ground cavity nesting bees compared to ground-nesting bees with hedgerow maturation; Ganser et al. reported increased overwintering of arthropod predators and pollinators of perennial compared to annual flower strips. Second, our findings reveal that higher species richness of flowering plants tends to enhance pollination service delivery in adjacent crops. This is an important finding as it indicates that restoring plant diversity can not only promote rare pollinator species and pollinator diversity , but also crop pollination services. Flowering plant diversity likely promotes complementary floral resources for numerous pollinator taxa with different resource needs and continuity of floral resource availability throughout the season . The identification of species or traits contributing particularly strongly to such effects is a promising area of research . Moreover, appropriate management, such as reducing the frequency of hedgerow cutting, is important to ensuring high availability and diversity of floral resources . Our synthesis reveals that floral plantings enhance pollination services, but only in the part of adjacent crops near to plantings, declining exponentially with distance to plantings . The exponential decline function predicts pollination service provisioning of less than 50% at 10 m and slightly more than 20% at 20 m compared to the level of service provisioning directly adjacent to plantings, partially explaining the overall non-significant benefits when considering all measured distances across the entire field . This may also explain part of the high variability observed across studies and reconcile some of the contrasting findings with respect to pollination service provisioning in studies measuring services relatively near plantings , or up to larger distances, e.g. up to 200 m; Morandin and Kremen ; Sardinas ~ et al. We found no indication that the degree of the dependency of a crop on insect pollination significantly contributed the observed variability in effects of plantings on crop pollination services or yield .
Consistent with previous studies , landscape simplification was associated with decreased pollination services, irrespective of the presence of floral plantings. In contrast, no such effects were detected for pest control services, in agreement with recent studies . The effect of adding a flower strip or hedgerow was, however, independent of landscape context. Although individual case studies found support for the intermediate landscape hypothesis, enhanced ecosystem services associated with floral plantings were not generally limited to moderately complex landscape contexts, which should encourage farmers to adopt these measures irrespective of the type of landscape in which they are farming. Crop yield is affected by a complex interplay of a multitude of agricultural management practices such as fertilisation, level of pesticide use, pest pressures, soil cultivation and other factors such as local soil and climatic conditions , which can potentially mask benefits from improved natural pest regulation or pollination services . Positive effects of floral plantings have been shown by some case studies included in this synthesis , although sometimes only several years after the establishment of plantings , but we did not detect consistent effects on crop yield associated with adjacent floral plantings. The identified drivers of the effectiveness of floral plantings to enhance crop pollination services, such as age and flowering plant diversity, could provide promising pathways towards optimising plantings as measures contributing to ecological intensification. Future optimisations should also consider the potential for synergistic interactions of enhanced pollination and pest control services by ‘multi-service’ designs of plantings , temporal dynamics , optimised ratios of floral planting to crop area , and the distance-dependency of services quantified by this synthesis. However, floral plantings are also established for other goals than yield increase. From an environmental and health perspective, maintaining crop yields through a replacement of insecticides by enhanced natural pest control services, should be considered as a great achievement . Moreover, floral plantings, of sufficient ecological quality, for example in terms of native plant species diversity, contribute also to further ecosystem services, especially biodiversity conservation ; but farmers are often reluctant to adopt such measures due to concerns of negative effects on crop yield, for example due to spillover of pests. Our findings of similar crop yield in fields with and without plantings can dispel such concerns.Our synthesis demonstrates enhanced natural pest control services to crops adjacent flower strips plantings, across a broad suite of regions, cropping systems and types of flower strips studied. However, it also reveals inconsistent and highly variable effects of flower strips and hedgerows on crop pollination services and yield. This highlights a strong need to identify the key factors driving this variability and the effectiveness of different types of floral plantings in contributing to ecosystem service delivery. Informed by such improved understanding, the design, hydroponic dutch buckets implementation and management of floral plantings can increase their effectiveness as measures for ecological intensification. This synthesis identifies several promising pathways towards more effective floral plantings for the provision of ecosystem services and ecological intensification: the modelled exponential distance-decay function of pollination service provisioning by floral plantings into crop field helps to predict service provision in crop fields; together with the lack of a strong planting area effect, our findings suggest that a dense spatial network of relatively small plantings will be more effective than a few large ones to optimise pollination service provisioning. Moreover, it identifies important drivers of the effectiveness of floral plantings for delivery of crop pollination services: flowering plant diversity and age.
Based on these findings we strongly encourage the establishment, adequate management and restoration of existing perennial floral plantings that ensure the availability of high floral diversity across several years as promising pathways towards optimised measures for ecological intensification.Since domestication efforts began in the early 1900s, highbush blueberry has rapidly become a high-value fruit crop worldwide. Highbush blueberry, compared to hundreds of closely related blueberry species in the Ericaceae, is widely cultivated due to its adaptation to temperate climates, excellent fruit quality, yield, and composition of phytonutrients. As a result for the demand for fresh blueberries as a ”superfruit”, highbush blueberry production has increased 600% during the past three decades and steadily grown to a multi-billion dollar industry. In addition to its short domestication history, highbush blueberry is unique in being one of only three major commercially valuable fruit crops, accompanied by cranberry and the garden strawberry, with wild progenitor species native to North America. Blueberries have a single epidermal layer that expresses a rich profile of anthocyanins during ripening that, in combination with epicuticular wax, generates its characteristic ”powdery blue” color. The cuticular and epidermal layers contain nearly all of the phytonutrients in the fruit such as anthocyanins, proanthocyanidins, and flavonols. Previous studies on blueberry have reported that these groups of compounds may have diverse health-promoting properties, including controlling diabetes, improving cognitive function, and inhibiting tumor growth. With the growing awareness of the potential health benefits of blueberry and increasing consumer demand, a primary goal of the blueberry research community is to develop cultivars with improved antioxidant levels along with other important fruit quality traits. However, despite its economic importance and health benefit potential, breeding efforts to improve fruit quality traits in blueberry have been slow due, in large part, to the lack of genomic resources. A draft genome for a wild diploid species of blueberry was previously assembled. However, that draft genome consists of a large number of scaffolds , high percentage of gaps in a ∼393.16 Mb assembly, and, most importantly, does not reflect the genome complexity of the economically important and cultivated tetraploid highbush blueberry. Here, we present the first chromosome-scale genome assembly of tetraploid highbush blueberry. The haplotype-phased assembly consists of 48 pseudomolecules with ∼1.68 Gb of assembled sequence, ∼1.29% gaps, and an average of 32,140 protein coding genes per haplotype . A haplotype is the complete set of DNA within the nucleus of an individual that was inherited from one parent. We leveraged this genome to examine the origin of the polyploid event, gain insights into the underlying genetics of fruit development, and identify candidate genes involved in the biosynthesis of metabolites contributing to superior fruit quality. Furthermore, we examined gene expression patterns among the four haplotypes in highbush blueberry. This analysis uncovered the presence of spatial-temporal specific dominantly expressed subgenomes. These findings and the reference genome will serve as a powerful platform to further investigate ”subgenome dominance”, facilitate the discovery and analysis of genes encoding economically important traits, and ultimately enable molecular breeding efforts in blueBerry.Our goal was to obtain a high-quality reference genome for the highbush blueberry cultivar ”Draper,” which is widely grown around the world due to its excellent fruit quality. We sequenced the genome using a combination of both 10× Genomics and Illumina , totaling 324X coverage of the genome . These data were assembled and scaffolded using the software package DenovoMAGIC3 . The genome was further scaffolded to chromosome-scale using Hi-C data with the HiRise pipeline . The total length of the final assembly is 1,679,081,592 bases distributed across 48 chromosome-level pseudomolecules . The final assembly size falls within the estimated genome size of ”Draper” based on flow cytometry . The genome was annotated using a combination of evidence based and ab initio gene prediction using the MAKER-P pipeline . RNA sequencing data from 13 different gene expression libraries, representing unique organs, developmental stages, and treatments , and publicly available transcriptome and expressed sequence tags data of V. corymbosum in theNational Center for Biotechnology Information were used as transcript evidence.