60 research outputs found
Recommended from our members
Landscape impacts on pollinator communities in temperate systems: evidence and knowledge gaps
Summary
1. This review assesses current knowledge about the interplay between landscape and pollinator communities. Our primary aim is to provide an evidence base, identify key gaps in knowledge and highlight initiatives that will help develop and improve strategies for pollinator conservation.
2. Human-dominated landscapes (such as arable land and urban environments) can have detrimental impacts on pollinator communities but these negative effects can be ameliorated by proximity to semi-natural habitat and habitat corridors. There is also evidence to suggest that increased landscape heterogeneity and landscape configuration can play an important role in the maintenance of diverse pollinator communities.
3. Landscape characteristics have direct impacts on pollinator communities but can also influence abundance and richness through interaction with other drivers such as changing climate or increased chemical inputs in land management.
4. The majority of existing literature focuses on specific hymenopteran groups but there is a lack of information on the impact of landscape changes on non-bee taxa. Research is also needed on the effectiveness of management interventions for pollinators and multiple year observations are required for both urban and rural initiatives.
5. Current policies and monitoring schemes could contribute data that will plug gaps in knowledge, thus enabling greater understanding of relationships between landscapes and pollinator populations. This would in turn help design mitigation and adaptation strategies for pollinator conservation
Recommended from our members
The benefits of hedgerows for pollinators and natural enemies depends on hedge quality and landscape context
Ecological intensification advocates the harnessing of regulating and supporting ecosystem services to promote more sustainable food production, and this relies on effective management of non-cropped habitats. Hedgerows are an important component of the landscape in many farming systems across the world, management of which provides a potential mechanism to enhance ecological intensification. Here we investigate the value of hedgerows in Southern England as a source of functionally important taxa, and how hedgerow quality and local landscape composition impact on their potential contribution to sustainable agriculture in arable landscapes. We show that hedgerows are a source habitat for many natural enemies which spill over into neighbouring fields, and that hedgerows provide a valuable forage resource and corridor for movement of pollinators. Hedgerow quality affects these benefits and continuous unbroken hedgerows, with a high diversity of woody species, are more valuable for the provision of bumblebees and Linyphiid spiders, while the presence of trees within the hedgerow supports Lycosid spiders. Floral resources, beyond the woody hedgerow species themselves, are also a key forage resource for hoverflies. The impact of these hedgerows on invertebrate abundance is moderated by local landscape, and hedgerows are a more valuable forage resource for pollinators in more intensely managed landscapes. Our study shows that in order to support abundant and a broad range of natural enemies and pollinators in agricultural landscapes, both hedgerows and local semi-natural habitats need to be protected and managed. The benefit of hedgerows, as a habitat for functionally important taxa depends on hedgerow quality and management practices such as avoiding gaps, high hedge species diversity and maintaining an abundant understory of plants, can improve their value for ecological intensification
Recommended from our members
Above‐ and below‐ground assessment of carabid community responses to crop type and tillage
Carabid beetles are major predators in agro‐ecosystems. The composition of their communities within crop environments governs the pest control services they provide. An understudied aspect is the distribution of predacious carabid larvae in the soil.
We used novel subterranean trapping with standard pitfall trapping, within a multi‐crop rotation experiment, to assess the responses of above‐ and below‐ground carabid communities to management practices.
Crop and trap type significantly affected pooled carabid abundance with an interaction of the two, the highest numbers of carabids were caught in subterranean traps in barley under sown with grass.
Trap type accounted for the most variance observed in carabid community composition, followed by crop.
Tillage responses were only apparent at the species level for three of the eight species modelled.
Responses to crop type varied by species. Most species had higher abundance in under‐sown barley, than grass, wheat and barley. Crop differences were greater in the subterranean trap data. For predaceous larvae, standard pitfalls showed lowest abundances in under‐sown barley, yet subterranean traps revealed abundances to be highest in this crop.
Comprehensive estimation of ecosystem services should incorporate both above‐ and below‐ground community appraisal, to inform appropriate management
Recommended from our members
Climate change, ecosystem impacts and systemic risks
Politicians, strategists and environmental campaigners are increasingly concerned about the potential for climate change to create major systemic risks with extreme – and controversially existential – consequences. These systemic risks may be triggered not only by the direct physical impacts of climate change – on heatwaves, floods, fires and drought – but also by the effects of ecosystem changes generated by climate change. However, there have so far been very few robust analyses of systemic risks under different future emissions pathways. Moreover, whilst there have been several studies of direct physical risks, there are very few studies into ecosystem changes in terms directly relevant to human systems. This is partly because ecosystems are inherently difficult to model because they are based on complex inter-relationships, and partly because most studies have concentrated on indicators relevant to ecosystems in themselves.
This report presents a review of the evidence available to support the robust assessment of the potential for ecosystem changes to trigger regional and global systemic risks. Such a robust assessment must involve a blend of quantitative information on relevant indicators calculated under different emissions pathways with expert judgment on how changes in exposure and vulnerability translate impacts into systemic risk. Ecosystem changes have the potential to generate regional and global systemic risk both through changes occurring over large areas and through changes occurring in particularly sensitive locations. Information on the effects of ecosystem changes should therefore be incorporated into this approach in two ways: using relevant high-level global-domain indicators combined with expert judgment on implications for human systems, and using expert judgment to identify critical sensitive locations and use locally-relevant indicators to infer impacts on ecosystems and systemic risks
Recommended from our members
Species matter when considering landscape effects on carabid distributions
Increasing the abundance and diversity of carabid beetles is a common objective of farm habitat management to deliver sustainable pest control. Carabid spatial distributions in relation to crop areas are important to the delivery of this ecosystem service.
We used pitfall count data at distances from edge habitats into crop centres, from farm sites across the UK, to determine the effects of in-field and adjacent environmental features on carabid abundance and diversity.
Overall carabid abundance increased towards the crop centre, whilst species richness and diversity decreased. The analyses of carabid abundance based on all the species pooled together strongly reflected the behaviour of the most abundant species. Species preferences varied by crop, soil type, and environmental features. For instance, some species were positively associated with habitats such as margins, while others responded negatively. This contrast in individual species models highlights the limitations on pooled models in elucidating responses.
Studies informing farm-habitat design should consider individual species’ preferences for effective enhancement of pest control services. Diverse cropping and landscape heterogeneity at the farm scale can benefit the varied preferences of individual species, help build diverse communities and, potentially increase service resilience and stability over time
Recommended from our members
Climate driven shifts in the synchrony of apple (Malus x domestica Borkh.) flowering and pollinating bee flight phenology
The phenology, or timing of key life-history events, of many globally important crops and the insects that pollinate them are shifting because of the changing climate. Where these temporal shifts occur at different rates or in
different directions, it induces a risk of phenological mismatch, potentially reducing the quality and quantity of
crop production. This study makes use of 48 years of UK citizen science (pollinating bee records) and systematic
(apple flowering) data to report phenological shifts of apples and their bee-pollinator community. It quantifies
the mismatches between peak flowering and flight dates which could potentially cause pollination deficits.
Flowering onset and peak flowering dates of Bramley apples advanced throughout the study period. This advance was primarily driven by early spring temperatures, with peak flowering dates advancing by 6.7 ± 0.9 per 1 °C warming. In addition, increasing spring rainfall significantly delayed flowering dates by 0.4 ± 0.1 days per 10 mm additional rainfall. By contrast, bee phenology shifted in a non-linear manner, advancing from 1970 to 1985 before plateauing until the end of the study period. The peak flight date of the apple pollinating bee community appears to be similarly sensitive to spring temperatures, experiencing an advance of 6.5 ± 2.1 days per 1 °C warming, although individual bee species responses to climate varied.
Furthermore, this study compared the phenological trends to assess the potential risk of asynchrony between crop and pollinator phenology. The different response patterns in the phenology of apples and bees led to shifting patterns of temporal mismatch between peak flowering and peak flight over time. Differences in sensitivity to climate do not appear to directly contribute to the phenological mismatch. Finally, this study highlights the potential value of citizen science data (with sufficient quality control) in understanding phenological shifts and mismatches and highlights potentially increasing temporal mismatch between apple trees and their bee pollinators
Recommended from our members
A whole ecosystem approach to pear psyllid (Cacopsylla pyri) management in a changing climate
Whole ecosystem-based approaches are becoming increasingly common in pest management within agricultural systems. These strategies consider all trophic levels and abiotic processes within an ecosystem, including interactions between different factors. This review outlines a whole ecosystem approach to the integrated pest management (IPM) of pear psyllid (Cacopsylla pyri Linnaeus) within pear (Pyrus communis L.) orchards, focusing on potential disruptions as a result of climate change. Pear psyllid is estimated to cost the UK pear industry £5 million per annum and has a significant economic impact on pear production globally. Pesticide resistance is well documented in psyllids, leading many growers to rely on biological control using natural enemies during the summer months. In addition, multiple insecticides commonly used in pear psyllid control have been withdrawn from the UK and Europe, emphasizing the need for alternative control methods. There is growing concern that climate change could alter trophic interactions and phenological events within agroecosystems. For example, warmer temperatures could lead to earlier pear flowering and pest emergence, as well as faster insect development rates and altered activity levels. If climate change impacts pear psyllid differently to natural enemies, then trophic mismatches could occur, impacting pest populations. This review aims to evaluate current strategies used in C. pyri management; discuss trophic interactions within this agroecosystem and highlight potential changes in the top-down and bottom-up control of C. pyri as a result of climate change. This review provides a recommended approach to pear psyllid management, identifies evidence gaps and outlines areas of future research
Recommended from our members
Scales matter: maximising the effectiveness of interventions for pollinators and pollination
Evidence of declines in wild and managed pollinators and pollination services is increasingly being documented around the world. This has driven the development of a wide range of practical management and policy responses which were reviewed in the Intergovernmental science-policy Platform on Biodiversity and Ecosystem Services (IPBES) global assessment of ‘Pollinators, Pollination and Food Production’. We take 38 responses from this report as a basis to explore the importance of scale for the effective delivery of an intervention’s benefit to pollinators. We considered five scale categories: Spatial, the spatial scale at which the response is most effective; Temporal, the time scale over which the response is most effective; Actors, the number of actors needed for most effectively implementing a response; Social, the sphere of influence or motivation that determines an effective response; and, Sector, the sector(s) of society which should be involved to increase effectiveness. Each scale category was split into multiple levels and we scored each in terms of how important they
were for determining the effectiveness of a given response option. Using our combined scores, we aim to explore general trends and raise awareness around the main issues
relating to the importance of scale, with illustrated examples from the literature. We show how scales have impacted on the effectiveness of interventions and provide recommendations on how to improve scale matching when planning a response action. While the relative importance of scales and levels for effectiveness was heterogeneous
across response options, there were some general patterns. Interventions were only effective when targeted over the right spatial scales over a sufficient period of time
and involved all relevant social and sectoral groups and actors
Recommended from our members
Biodiversity 2020: climate change evaluation report
In 2011, the government published Biodiversity 2020: A strategy for England’s wildlife and ecosystem services [1]. This strategy for England builds on the 2011 Natural Environment White Paper - NEWP [2] and provides a comprehensive picture of how we are implementing our international and EU commitments. It sets out the strategic direction for biodiversity policy between 2011-2020 on land (including rivers and lakes) and at sea, and forms part of the UK’s commitments under the ‘the Aichi targets’ agreed in 2010 under the United Nations Convention of Biological Diversity’s Strategic Plan for Biodiversity 2011-2020 [3].
Defra is committed to evaluating the Biodiversity 2020 strategy and has a public commitment to assess climate change adaptation measures. This document sets out the information on assessing how action under Biodiversity 2020 has helped our wildlife and ecosystems to adapt to climate change. Biodiversity 2020 aims to halt the loss of biodiversity and restore functioning ecosystems for wildlife and for people. The outcomes and actions in Biodiversity 2020, although wider in scope, aimed to increase resilience of our wildlife and ecosystems in the face of a changing climate. In order to inform the assessment, we have defined which of the measurable outputs under Biodiversity 2020 contribute to resilience. Biodiversity 2020 included plans to develop and publish a dedicated set of indicators to assess progress towards the delivery of the strategy. The latest list (at the time of writing), published in 2017, contains 24 biodiversity indicators [4] that would help inform progress towards achieving specific outcomes, they are also highly relevant to the outputs (detailed below) that form the basis for this evaluation. The Adaptation Sub-Committee’s 2017 UK Climate Change Risk Assessment Evidence Report [5] sets out the priority climate change risks and opportunities for the UK. The ASC also produced a review of progress in the National Adaptation Programme - “Progress in preparing for climate change” [6], which highlights adaptation priorities and progress being made towards achieving them. The UK Government’s response to the ASC [7] review includes a set of recommendations, of which Recommendation 6 states that “Action should be taken to enhance the condition of priority habitats and the abundance and range of priority species”. The recommendation further iterated that “This action should maintain or extend the level of ambition that was included in Biodiversity 2020” and that “An evaluation should be undertaken of Biodiversity 2020 including the extent to which goals have been met and of the implications for resilience to climate change.” To this, end an evaluation process has been put in place to define:
a. What worked and why? Which actions or activities have had the greatest benefit in terms of delivering the desired outcomes? And, conversely, what prevented progress?
b. Where are the opportunities? What are the financial, political, scientific and social opportunities for furthering the desired outcomes in the future?
These objectives underpin the evaluation process for actions to date, and will also inform future actions and the iteration of a new nature strategy for England
- …