321 research outputs found
Winter Active Bumblebees (Bombus terrestris) Achieve High Foraging Rates in Urban Britain
Background: Foraging bumblebees are normally associated with spring and summer in northern Europe. However, there have been sightings of the bumblebee Bombus terrestris during the warmer winters in recent years in southern England. But what floral resources are they relying upon during winter and how much winter forage can they collect? Methodology/Principal Findings: To test if urban areas in the UK provide a rich foraging niche for bees we set up colonies of B. terrestris in the field during two late winter periods (2005/6 & 2006/7) in London, UK, and measured their foraging performance. Fully automatic radio-frequency identification (RFID) technology was used in 2006/7 to enable us to record the complete foraging activity of individually tagged bees. The number of bumblebees present during winter (October 2007 to March 2008) and the main plants they visited were also recorded during transect walks. Queens and workers were observed throughout the winter, suggesting a second generation of bee colonies active during the winter months. Mass flowering shrubs such as Mahonia spp. were identified as important food resources. The foraging experiments showed that bees active during the winter can attain nectar and pollen foraging rates that match, and even surpass, those recorded during summer. Conclusions/Significance: B. terrestris in the UK are now able to utilise a rich winter foraging resource in urban parks and gardens that might at present still be under-exploited, opening up the possibility of further changes in pollinato
Giles Fletcher, the elder (1546-1611) and the writing of Russia.
In the historiography of early modern exploration, travel and trade, the English 'discovery' of Russia has been sidelined by western European experiences of the Americas, despite its important role in English adventuring activities. This thesis contributes to redressing this imbalance by exploring Elizabethan perceptions of Russia, through an in-depth analysis of the work of Giles Fletcher, the elder (1546-1611). Fletcher was sent as Elizabeth's ambassador to Russia in 1588. On his return he wrote and later published Of the Russe Commonwealth (1591). This was a controversial text on its first publication and had a fascinating afterlife over the next three hundred years
Editorial: EFSA calls for integrated and coordinated actions at EU and international levels to address global declines of pollinators
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Yield-biodiversity trade-off in patchy fields of Miscanthus Ă giganteus
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, Miscanthus 9 giganteus 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 (4â5 years 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. Keywords: Araneae, Carabidae, crop cover, light penetration, Miscanthus establishment, patchiness, vascular plants, vegetation coverYield-biodiversity trade-off in patchy fields of Miscanthus Ă giganteuspublishedVersio
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Pollinator selection against toxic nectar as a key facilitator of a plant invasion
Plant compounds associated with herbivore defence occur widely in floral nectar and can impact pollinator health. We showed previously that Rhododendron ponticum nectar contains grayanotoxin I (GTX I) at concentrations that are lethal or sublethal to honeybees and a solitary bee in the plant's non-native range in Ireland. Here we further examined this conflict and tested the hypotheses that nectar GTX I is subject to negative pollinator-mediated selection in the non-native range, but that phenotypic linkage between GTX I levels in nectar and leaves acts as a constraint on independent evolution. We found that nectar GTX I experienced negative directional selection in the non-native range, in contrast to the native Iberian range, and that the magnitude and frequency of pollinator limitation indicated that selection was pollinator-mediated. Surprisingly, nectar GTX I levels were decoupled from those of leaves in the non-native range, which may have assisted post-invasion evolution of nectar without compromising the anti-herbivore function of GTX I (here demonstrated in bioassays with an ecologically relevant herbivore). Our study emphasizes the centrality of pollinator health as a concept linked to the invasion process, and how post-invasion evolution can be targeted toward minimizing lethal or sub-lethal effects on pollinators
Stem-nesting Hymenoptera in Irish farmland: empirical evaluation of artificial trap nests as tools for fundamental research and pollinator conservation
peer-reviewedInsect pollinators are suffering global declines, necessitating the evaluation and development of methods for long-term monitoring and applied field research. Accordingly, this study evaluated the use of trap nests (âbee hotelsâ) as tools for investigating the ecology of cavity nesting Hymenoptera within Irish agricultural landscapes. Three trap nests consisting of 110 mm diameter plastic pipe containing 100 cardboard nest tubes of varying diameter were placed at eight apple orchards and eight oilseed rape sites and left in the field for five months. Sealed nest tubes occurred at 15 of the 16 sites, and in 77% of the 48 nests. However, only 7% of the 4800 individual nest tubes were sealed, and only 4% produced cavity-nesting Hymenoptera. Three cavity nesting bee species (Hylaeus communis, Osmia bicornis, Megachile versicolor) and two solitary wasp species (Ancistrocerus trifasciatus, A. parietinus) emerged from nest tubes. There were significant differences among species in terms of emergence date and the diameter of nest tubes from which they emerged, the latter allowing the calculation of niche width and niche overlap, and informing choice of tube size in future studies/conservation efforts. Trap nests, therefore, offer a valuable tool for fundamental ecological research and a model system for investigating interactions between stem-nesting species within their wider ecological networks. The ability of trap nests to actually increase farmland pollinator abundance and diversity as part of agri-environment schemes requires additional investigation. However, used in sufficient numbers, these trap nests provide valuable biogeographical data for cavity nesting Hymenoptera and offer a viable means for long term monitoring of these species in Irish farmland
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Globalisation and pollinators: pollinator declines are an economic threat to global food systems
1. Trade in animal-pollinated crops plays an important role in global food systems: in many low-income countries, export of pollinated crops such as coffee and cocoa plays a significant role in livelihoods, while food systems in many higher income nations depend on international trade in these crops to satisfy their local demands. Losses of pollination services therefore pose a significant risk to economies beyond the area directly affected.
2. Using a simple extension of a common economic model, we explore which countries are most affected by a loss of pollination services in three case study groups of 25 countries that are vulnerable to different risks: pesticide use, natural disasters and economic debts.
3. In all three cases, large, developed economies such as the United Kingdom, Germany and Japan, are estimated to suffer the greatest economic losses, even if pollinator losses only affect smaller, less-developed economies.
4. In cases where higher income countries are affected by pollinator losses, there is a significant shift in the value of global pollinated crop production towards other large, unaffected countries.
5. Our findings highlight the need for richer countries to invest in pollinator conservation beyond their own borders to maintain resilient food systems. We provide suggestions for further economic research to better understand and identify system vulnerabilities to pollinator losses
The Efficacy of a Health Promotion Intervention for Indigenous Women: Reclaiming Our Spirits
Indigenous women globally are subjected to high rates of multiple forms of violence, including intimate partner violence (IPV), yet there is often a mismatch between available services and Indigenous womenâs needs and there are few evidence-based interventions specifically designed for this group. Building on an IPV-specific intervention (Intervention for Health Enhancement After Leaving [iHEAL]), âReclaiming Our Spiritsâ (ROS) is a health promotion intervention developed to address this gap. Offered over 6 to 8 months in a partnership between nurses and Indigenous Elders, nurses worked individually with women focusing on six areas for health promotion and integrated health-related workshops within weekly Circles led by an Indigenous Elder. The efficacy of ROS in improving womenâs quality of life and health was examined in a community sample of 152 Indigenous women living in highly marginalizing conditions in two Canadian cities. Participants completed standard self-report measures of primary (quality of life, trauma symptoms) and secondary outcomes (depressive symptoms, social support, mastery, personal agency, interpersonal agency, chronic pain disability) at three points: preintervention (T1), postintervention (T2), and 6 months later (T3). In an intention-to-treat (ITT) analysis, Generalized Estimating Equations (GEE) were used to examine hypothesized changes in outcomes over time. As hypothesized, womenâs quality of life and trauma symptoms improved significantly pre- to postintervention and these changes were maintained 6 months later. Similar patterns of improvement were noted for five of six secondary outcomes, although improvements in interpersonal agency were not maintained at T3. Chronic pain disability did not change over time. Within a context of extreme poverty, structural violence, and high levels of trauma and substance use, some women enrolled but were unable to participate. Despite the challenging circumstances in the womenâs lives, these findings suggest that this intervention has promise and can be effectively tailored to the specific needs of Indigenous women
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