November 2010 Royal Horticultural Society Conference Centre
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Conference “Garden Wildlife in the International Year of Biodiversity” 17 th November 2010 Royal Horticultural Society Conference Centre Summaries of Contributions Page 2 Roger Williams. Science, gardening and biodiversity 3 Helen Bostock. Ladders, holes and pitfalls: year one for the RHS Plants for Bugs project 6 Jan Miller. Importance of brownfield sites and how to mimic them in the garden. 9 Margaret Couvillon How good is the British countryside for our honey bees? Decoding waggle dances to determine where the bees are foraging 11 Mike Toms Conservation status of garden birds 15 Jeremy Biggs What's really living in your garden pond? First results from Pond Conservation’s detailed garden pond research programme. 19 Mark Goddard Scaling up from gardens: Avian diversity in a residential ecosystem 23 Chloë Smith and Elaine Hughes. The LWT/GLA/GiGL Gardens Research Project - Investigating the nature of London’s gardens using aerial photography and GIS 26 June Greenaway The social science of wildlife gardening: Why some people choose to practice while others do not. 32 Steve Head So what IS the role of gardens in biodiversity conservation? The National Launch of Jennifer Owen’s book “Wildlife of a Garden: A Thirty-Year Study” 41 Ken Thompson Jennie Owen’s “invention” of Garden Ecology 42 Transcript of the Video of Jennifer Owen talking about her book. To join the Wildlife Gardening Forum contact Dr Steve Head at [email protected] 1 Roger Williams Royal Horticultural Society. Science, gardening and biodiversity Why should we care about garden biodiversity? Ecosystem Services, the processes that keep the biosphere inhabitable for us are vitally important – well illustrated by the apocalyptic cartoon Wall-E, where the eponymous robot is left behind to clean up a planet destroyed and abandoned by humans. Biodiversity delivers ecosystem services, and the sustainability to pass on what we enjoy to future generations. The cost to the world of not preserving ecosystems and biodiversity has recently been estimated at between £1.2 and £2.8 trillion a year 1. But it is also a source of wonder, joy and delight, and the biodiversity in gardens is usually the first that children encounter. Gardens are important for biodiversity, and biodiversity is vital for gardens. Gardens contain species we like, such as butterflies and ladybirds, but also things we don’t such as stinging nettles, slugs and honey fungus. People need help to understand how garden ecology works. The RHS Science Strategy is designed to help biodiversity as well as people. The core need is biosystematics – knowing exactly what species of animals and plants we are dealing with. Above this layer we need experimental studies to understand how these creatures work together, from which we can then offer sound evidence-based advice and information to gardeners. But we don’t want to lose sight of the end product – the sheer joy and satisfaction that a garden and its inhabitants can give. According to BMW “Joy likes “AND” not “OR”, and so it should be with gardening. There is no reason why we should not have biodiverse and sustainable gardens that are also beautiful and a source of joy. Encouraging wildlife is one of the RHS Science Strategy’s top 5 themes, and the Forum-initiated Plants for Bugs project is an excellent example of what we hope to achieve. The RHS sees a key role for the Forum, and is actively participating with RHS entomologist Andy Salisbury now heading the Forum’s Research Group, identifying information needs and new potential collaborative projects. 1 www.nhm.ac.uk/nature-online/biodiversity/why-conserve-biodiversity/index.html 2 Helen Bostock Royal Horticultural Society. Plants for Bugs Project Manager Ladders, holes and pitfalls: year one for the RHS Plants for Bugs project. Forum members first heard of this project at the conference in March 2009, and those attending the Wisley conference in November last year will have seen one set of experimental plots. The Plants for Bugs experiment is designed to test the role native and non-native plants have for garden wildlife. About 30% of the plants in our gardens are British natives. Are the other 70% useful for wildlife or just bystanders? The experiment is a statistically powerful design, with two replicate sites, each with 18 3x3m planted plots. Each plot is planted with an assemblage of typical garden plants of one of three categories: a) British Natives (eg hemp agrimony Eupatorium cannabinum) b) Near natives plants from the northern hemisphere; non native but closely related (eg Joe Pye weed Eupatorium purpureum) c) Exotics - plants from the southern hemisphere; non-natives, unrelated but similar in habit to the native species (eg Verbena bonariensis) Setting up the plots A plants for bugs volunteer tending one of the near-native plots The experiment is now nearing the end of its first year of monitoring. No results can be announced yet, because it will be running for three years and the data will require full analysis before release. Four forms of monitoring for wildlife are in use: 1. Gastropod traps for slugs and snails Chicken feed (5g approx.) 25 cm plant pot saucer Soil level Small gap One trap is deployed 5 times per season in each plot, left for 48 hours to collect gastropods. Slugs are identified in the field, snails are brought to the lab for 3 determination. So far only 45 gastropods have been identified, far fewer than expected. It is likely the dry summer and Wisley’s dry sandy soils may to blame. 2. Pifall traps for ground beetles (Carabidae), woodlice and other ground-living fauna Ground level Preservative Plastic cup (tap water: ethylene glycol) (70 mm diam, 95 mm depth) One pitfall trap is set in the centre of each plot 5 times each season, and left for 2 weeks. The creatures captured are sorted and identified in the laboratory, (a notoriously tedious process). So far >6000 insects have been counted; and >100 species identified, including 30 species of ground beetle and four species of woodlice. 3. Vortis suction sampler for epigeal (above ground) arthropods – e.g. flies, aphids, caterpillars, true bugs, leafhoppers, beetles and their larvae The suction nozzle is hovered above the plants in the plots, with a ten second sample time in the central area, and 10 second sweeps along each side. This is repeated 5 times in each season Andrew Salisbury wielding the mighty Vortis suction sampler Like pitfall traps, samples have to be analysed in the lab. So far >2000 invertebrates have been counted and 70 species identified 4. Flying insect visitors - Bees (honey, bumble, solitary), wasps, butterflies, flies (incl. hoverflies) The sampling is performed by standing for eight minutes at the sides of each plot ( 4x 1min per side in morning and afternoon), observing the insect visitors, which are identified in the field.. Again the surveys are repeated five times each season. During 2010, >2300 invertebrates were observed visiting the plots; with 7 species of bumble bee and 12 species of butterfly. 4 Quite a number of hurdles have been encountered and overcome in this very original experiment. The exceptionally cold start to the year, plus the summer drought, caused some mortality especially among the exotics, and a volunteer watering team was set up to keep the plants alive. The wooden edging boards used to contain and define the plots proved an obstacle to ground insects. This was cured by boring 5,760 1.25 inch diameter holes in the boards in less than a month. Difficulties were found with taking overhead photographs of the plots for recording plant growth. This was solved using a very tall tripod-ladder, enabling non-acrophobic team members to photograph from directly above the centre. Tripod ladder in use In 2011 and beyond, the field work and lab analysis will continue, helped by Sarah Al- Beidh, who joined the project under the Knowledge Transfer Partnership with Reading University. Spin-off projects including soil fauna are considered, and the web pages and blog are expanding. See: www.rhs.org.uk/plants4bugs 5 Jan Miller Saith Ffynnon Wildlife Plants. Importance of brownfield sites and how to mimic them in the garden. I have been a volunteer for Butterfly Conservation for over 10 years, and during that time have studied a number of brownfield sites. Recently I published a book on ‘Gardening for Butterflies, Bees and other beneficial insects’ which is unashamedly a large, colourful, ‘coffee table’ book because I am trying to get across to the general public who still think insects are nasty, stinging creepy-crawlies that we could well do without. This talk is a much-abridged version of one section of the book. So what is a brownfield site? • Any site that has been altered by Man’s activity. • Includes derelict areas in towns, quarries, brick-pits, disused railways, disused factories and airfields. And why are they important for biodiversity? • Our green rolling fields are now a desert for wildlife; intensive farming has led to much of our countryside becoming cold, monoculture rye-grass, with little larval food or habitat for insects, and this has led to a decline of invertebrates that feed wild birds, bat, amphibians, reptiles and small mammals. • Brownfield sites have as many associated Red Data and Nationally Scarce invertebrate species as do ancient woodlands.2 • Buglife has led some high profile campaigns for the Thames Gateway area, and although their court case to save the Thurrock Marshes from development failed, it earned the charity a major award. 3. What are the main features of brownfields that makes them so attractive to wildlife? They are a habitat mosaic that has: • Different temperature gradients within short distances • Bare ground for warmth and burrowing • Many nesting and hibernation sites • Wild larval foodplants • Nectar sources throughout the year • not sprayed, fertilised or ploughed • sharp drainage, bare seedbed, • Infertile; little competition from other plants.