Citizen science data reveals the need for keeping garden plant recommendations up-to-date to help pollinators

Widespread concern over declines in pollinating insects has led to numerous recommendations of which “pollinator-friendly” plants to grow and help turn urban environments into valuable habitat for such important wildlife. Whilst communicated widely by organisations and readily taken up by gardeners, the provenance, accuracy, specificity and timeliness of such recommendations remain unclear. Here we use data (6429 records) gathered through a UK-wide citizen science programme (BeeWatch) to determine food plant use by the nations’ bumblebee species, and show that much of the plant use recorded does not reflect practitioner recommendations: correlation between the practitioners’ bumblebee-friendly plant list (376 plants compiled from 14 different sources) and BeeWatch records (334 plants) was low (r = 0.57), and only marginally higher than the correlation between BeeWatch records and the practitioners’ pollinator-friendly plant list (465 plants from 9 different sources; r = 0.52). We found pollinator-friendly plant lists to lack independence (correlation between practitioners’ bumblebee-friendly and pollinator-friendly lists: r = 0.75), appropriateness and precision, thus failing to recognise the non-binary nature of food-plant preference (bumblebees used many plants, but only in small quantities, e.g. lavender—the most popular plant in the BeeWatch database—constituted, at most, only 11% of records for any one bumblebee species) and stark differences therein among species and pollinator groups. We call for the provision and use of up-to-date dynamic planting recommendations driven by live (citizen science) data, with the possibility to specify pollinator species or group, to powerfully support transformative personal learning journeys and pollinator-friendly management of garden spaces

From citizen science to citizen action: analysing the potential for a digital platform to cultivate attachments to nature

Identifying private gardens in the UK as key sites of environmental engagement, we look at how a longer-term online citizen science programme facilitated the development of new and personal understandings of nature. These were visible through new or renewed interest in wildlife-friendly gardening practices and attitudinal shifts in a large proportion of its participants. Qualitative and quantitative data, collected via interviews, focus groups, surveys and logging of user behaviours, revealed that cultivating a fascination with species identification was key to both ‘helping nature’ and wider learning, with the programme creating a space where scientific and non-scientific knowledge could co-exist and reinforce one another

Supporting beneficial insects with wildflowers in gardens and vineyards

Land-use change and habitat destruction have reduced biodiversity to the extent that 60% of ecosystem services are considered degraded. Ecological habitat management aims to regulate ecological functions, including ecosystem services such as pest control and pollination. My research has focused on the planting of wildflowers as habitat management for beneficial insects in allotments, gardens and vineyards, as intensively managed, lesser-studied landscapes. The estimated 400,000 ha of UK gardens provide considerable potential pollinator habitat, although a commonly perceived barrier to wildlife gardening is lack of space. Using citizen science, I investigated the effectiveness of a small 4 m2 wildflower patch in recruiting beneficial insects, allocating participants to one of three treatment groups (two wildflower mixes and control) who sampled insects in their private gardens and allotments. Small wildflower patches provided resource-rich habitats, with different treatments attracting different taxa. To assess the ability of a wildflower to attract pollinators to a crop and increase pollination services, I introduced bee-friendly borage as a companion plant co-located with a strawberry plant. In this citizen science project, I found that strawberries companion planted with borage produced significantly more fruit, and fruit of higher aesthetic quality. Verification of the results of both citizen science projects allowed the analysis of effective sampling methods and possible bias in projects conducted in private urban spaces. UK agri-environmental schemes have yet to make vineyard-specific recommendations to support biodiversity in viticulture, despite it being one of the fastest-growing sectors of English agriculture. By conducting insect and floral surveys in a British vineyard, I tested five inter-row treatments (three wildflower mixes, natural regeneration, and mown grass) on their potential in supporting beneficial insects. Sown and spontaneous wildflowers significantly increased insect abundance and richness, with no loss of space for grapevines. I engaged directly with British viticulturists through a survey to understand current management practices and barriers to adopting wildlife-friendly approaches. The majority of respondents reported reliance on synthetic pesticides, having grass-only inter-row cover and frequent summer mowing. Based on the findings in my thesis, I encourage the establishment, management and restoration of floral plantings in vineyards, gardens and allotments. Wildflowers can attract beneficial insects in these environments, enhancing biodiversity, benefiting ecosystem services and contributing to a sustainable future of viticulture and urban agriculture

Pollination ecosystem services and the urban environment

Insect pollination is a vital ecosystem service, essential for both wild and domesticated plants, yet to-date there are no standardised national schemes to monitor its status. Thus this PhD focused on assessment of pollination provision in UK urban green spaces, using a combination of citizen science and field/laboratory methods. Each of the following thesis chapters considers a specific pollination-related theme: The need for pollination. Demonstrating how much gardeners need insect pollination is important to underpin public support for pollinator conservation. During 2014-2015, online questionnaires were used to collect information about the crops grown in domestic green spaces and gardening practices used. Participants highly valued ‘growing their own’, and three of five crops grown by the majority (tomatoes, apples, strawberries) have high requirements for insect pollination. A ‘garden shop calculator’ spreadsheet was also tested (positively) as a quick way to calculate the equivalent bought-value of garden crops and the proportion directly attributable to insect actions. Assessment of pollination provision. Citizen science volunteers undertook a simple direct pollination experiment (exclusion, hand pollination, local), requiring treatment randomisation and accurate yield recording. The main ‘Bees ‘n Beans’ projects used Vicia faba to monitor bumblebee pollination, detecting no national deficit during 2014-2016. This suggests that the domestic pollination needs of V. faba are currently met, and that urban populations of long-tongued bumblebees are sufficient to provide it. The potential of using other plants to cover wider pollinator populations was also explored, identifying Allium hollandicum as suitable. The effects of companion planting. Using tomato plants to examine whether co-planting crops with flowering plants boosts pollination provision (‘magnet species’ effects), or distracts insects. Provided plants were hosted in volunteered gardens and school grounds in Brighton in 2015 & 2016. No effect (improved or detrimental) of co-flowering plants was found on tomato yields at either site type. Using citizen science to monitor pollination services. This chapter combined findings from other chapters and a final questionnaire, which focused on participants’ motivations and willingness to make behavioural changes after taking part. It concludes that the projects have demonstrated volunteers’ ability and willingness to follow experimental protocols under guidance, to collect meaningful data at otherwise-impractical geographical scales. Suggested protocol. This details the finalised Bees ‘n Beans approach and how it relates to other potential pollination monitoring methods. I propose that this style of project is suitable for incorporation into national monitoring scheme development

Quantifying the attractiveness of garden flowers for pollinators

There is great interest in planting urban areas to benefit pollinating insects, with the potential that urban areas and gardens could act as an extensive network of pollinator-friendly habitats. However, there are a great many different plant cultivars available to the gardener, and a paucity of evidence-based advice as to which plants are truly most attractive to flower-visiting insects. Here, we report insect visitation to metre square plots of 111 different ornamental plant cultivars at a site in central UK. Data were collected over 5 years, and comprise over 9000 insect observations, which were identified to species (for honeybees and bumblebees) or as ‘solitary bees’, Syrphidae, Lepidoptera and ‘others’. Unlike some previous studies, we found no difference in numbers of insects attracted to native or non-native species, or according to whether plants were annuals, biennials or perennials, but we did find that native plants attracted a significantly higher diversity of flower-visiting insects. Overall, the most-visited plants were Calamintha nepeta, Helenium autumnale and Geranium rozanne. However, patterns of visitation were quite different for every insect taxa examined. For example, different species of short-tongued bumblebees showed little overlap in their most-preferred plant cultivars. Interestingly, very similar plant cultivars often attracted different insect communities; for example, 72% of visitors to Aster novi belgii were honeybees or bumblebees, while the related Anthemis tinctoria, which also has daisy-like flowers, did not attract a single honeybee or bumblebee but was popular with solitary bees, hoverflies, and ‘other’ pollinators. Some plant cultivars such as Eryngium planum and Myosotis arvensis were attractive to a broad range of insects, while others attracted only a few species but sometimes in large numbers, such as Veronicastrum virginicum and Helenium autumnale which were both visited predominantly by honey bees. It is clear that we do not yet fully understand what factors drive insect flower preferences. Recommendations are made as to which flower cultivars could be combined to provide forage for a diversity of pollinator groups over the season from early spring to autumn, though it must be born in mind that some plants are likely to perform differently when grown in different environmental conditions

Opportunities and threats for pollinator conservation in global towns and cities

Urban expansion is considered to be one of the main threats to global biodiversity yet some pollinator groups, particularly bees, can do well in urban areas. Recent studies indicate that both local and landscape-level drivers can influence urban pollinator communities, with local floral resources and the amount of impervious cover in the landscape affecting pollinator abundance, richness and community composition. Urban intensification, chemicals, climate change and increased honey bee colony densities all negatively affect urban pollinators. Maintaining good areas of habitat for pollinators, such as those found in allotments (community gardens) and domestic gardens, and improving management approaches in urban greenspace and highly urbanised areas (e.g. by increasing floral resources and nesting sites) will benefit pollinator conservation. Opportunities for pollinator conservation exist via multiple stakeholders including policymakers, urban residents, urban planners and landscape architects

Responses to risks and opportunities associated with pollinators and pollination

The overall aim of the thematic assessment of Pollinators, Pollination and Food Production is to assess animal pollination as a regulating ecosystem service under pinning food production in the context of its contribution to nature'sgifts to people and supporting a good quality of life. Toachieve this, the focus is on the role of native and exoticpollinators, the status of, and trends in pollinators andpollinator-plant networks and pollination, drivers of change,impacts on human well-being, food production in responseto pollination declines and deficits and the effectiveness ofresponses from various governance systems to pollinationdeclines and deficits. The scope is global, covering allcontinents except Antarctica, where no pollinators areknown. The assessment brings together contributions notonly from natural, social and economic science perspectives but also from knowledge of indigenous and local community stake holders and practitioners.The assessment strives to critically review the broadest range of evidence and make its findings readily availableto support policy and management responses to declinesand deficits in pollination. The report represents the firstIPBES thematic assessment deliverable that aims toidentify policy-relevant findings for decision-making ingovernment, the private sector and civil society, as wellas helping to demonstrate how an essential ecosystem service could potentially contribute to the post-2015 development agendaFil: Dicks, Lynn. University of Cambridge; Reino UnidoFil: Viana, Blandina Felipe. Universidad federal de Bahia; BrasilFil: del Coro Arizmendi, Maria. Universidad Nacional Autónoma de México; MéxicoFil: Bommarco, Riccardo. Mid Sweden University.; SueciaFil: Brosi, Berry. University of Washington; Estados UnidosFil: Cunningham, Saul. Australian National University; AustraliaFil: Galetto, Leonardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; ArgentinaFil: Lopes, Ariadna. Universidade Federal de Pernambuco; BrasilFil: Taki, Hisatomo. University of Florida; Estados Unido