Vegetation and climate : a thirty-six year study in road verges at Bibury, Gloucestershire.

The long-term study, initiated by Professor Arthur Willis in 1958, of the vegetation of permanent plots in road verges at Akeman Street, near Bibury, Gloucestershire, is a unique and valuable record of annual variations in shoot biomass of individual species, and of the vegetation as a whole, over a 38-year period. The study was originally devised to monitor the effects of herbicides and a growth regulator on roadside vegetation. However, more recently, in the context of the possible effects of climate change on indigenous vegetation, interest has centred on data from the untreated control plots and their potential in detecting long-term plant/weather relationships. In Part 1 of this thesis, annual fluctuations in the de-trended or flat-trended aboveground biomass of over 40 plant species at Bibury are compared with three orders of climatic variables: individual weather variables such as temperature, rainfall and sunshine; the frequency of 'Lamb weather types' (anticyclonic, cyclonic and westerly weather), which in large part determines rainfall, sunshine and temperature; and with the changing position of the Gulf Stream in the North Atlantic, which may, in part, determine the frequency of weather types over the UK. In all comparisons, markedly non-random climate/plant relationships were detected. The responses of Bibury taxa to individual weather variables matched closely their responses to weather types. The analyses presented here agree with other studies which link a northerly Gulf Stream with increased frequencies of anticyclonic weather in spring and autumn and reduced frequencies in summer. It is suggested that plant species promoted by a more northerly Gulf Stream tend to be robust perennials with early phenologies or deep-rooted species which may exhibit a degree of drought avoidance, but which may also respond rapidly to favourable conditions in spring and summer. Overall, settled, hot, dry summers appear at Bibury to decrease the total productivity of the vegetation and promote the amount of bare ground in the ecosystem. Part 2 of the thesis describes experiments designed to explore the mechanistic basis of the plant/weather relationships at Bibury and to extend the relevance of the data-set beyond the site itself. Five species were selected which exhibit a range of responses to individual weather variables. The plants were grown in deep containers (rigid plastic bins) in monoculture and in five-species mixture. Treatments were applied out of doors to establish whether the responses observed in the field could be repeated under semi-controlled conditions. The species were: Achillea millefolium (promoted by warm dry springs and summers), Cirsium arvense (retarded by warm dry springs and summers and promoted by mild winters), Dactylis glomerata (retarded by mild winters), Festuca rubra (retarded by mild winters) and Poa pratensis (retarded by warm dry springs and summers). The treatments were: heating with electric cables at the soil surface in late winter and spring; application of a severe frost in late spring; and the imposition of a severe drought in summer. The treatments affected both the vegetative and reproductive vigour of the species involved. In the great majority of cases predicted responses were fulfilled under the experimental conditions (for example. Dactylis glomerata was shown to be dependant on winter chilling to achieve maximum reproductive potential, reflecting its reduced performance in the field at Bibury following mild winters). The five species were used to test current theories on genome size and plant response to unusually high temperatures in late winter and spring and to severe late frosts. As predicted, species with low nuclear DNA content tended to gain competitive advantage in mixture following the warming treatment, while those species with high nuclear DNA content showed evidence of reduced competitive ability. Also, as predicted small genome species tended to exhibit greater sensitivity to the late frost treatment. The experimental results provide valuable insights into the potential effects of weather on plant community dynamics and the relative competitive abilities of potential vegetation dominants and subordinates

Fourth Annual Greening Rooftops for Sustainable Communities Conference, Awards and Trade Show

Abstract The promotion of green roofs for their wider value for biodiversity has received great attention recently. Indeed, in a number of European cities, the main driver for implementation of green roofs is their habitat value, particularly where development on the ground is destroying or threatening protected or rare wildlife sites. A particular approach has developed that has lead to certain types of green roof being referred to as "biodiversity roofs", and a set of rules has emerged (closely related to concepts of restoration ecology) that typify an approach that is good for biodiversity. This paper reviews some of these rules or assumptions, using the latest scientific evidence, and evaluates their direct application to the green roof context. Specific aspects covered include: the use of native plant species only (assumed to be better fitted than non-natives to regional climates, and to support a wider range of other life than non-native plants); the use of locally-characteristic plant communities (assumed to provide local distinctiveness, and again because such communities are better fitted to local conditions); the use of local-provenance material and local ecotypes (assumed to preserve local genetic diversity and locally adapted populations); and the use of local soils and substrates (assumed to be better fitted to local conditions, to best support local vegetation, and to have lower "embodied energy" than other substrate

Perceived species-richness in urban green spaces: Cues, accuracy and well-being impacts

© 2017 The Authors Evidence that urban green-space promotes health and well-being of urban residents is increasing. The role of biodiversity is unclear: perceived biodiversity may be important, but how accurately it is perceived and the factors influencing this accuracy are poorly understood. We use experimental perennial urban meadows in southern England to investigate the impact of creating biodiverse habitats on green-space users’ i) physical and mental health, psychological well-being, ii) factors moderating health and well-being outcomes (site satisfaction and nature connectedness), and iii) perceived biodiversity. We explore whether ‘nature dose’ (time spent at a site) influences these relationships. We then assess whether green-space users can estimate botanical diversity accurately across meadow treatments differing in plant species richness and vegetation structure, and determine the environmental cues and personal characteristics associated with these estimates. Sites with experimental meadows did not increase respondents’ perceptions of site level biodiversity, their self-rated physical and mental health or psychological well-being relative to control sites lacking meadows. However, there were significant associations between perceived site level biodiversity per se, and site satisfaction and feeling connected to nature. Moreover, we observed a positive association between nature dose and self-estimated mental health. We found that actual and perceived botanical richness in individual meadow plots were strongly positively correlated. Perceived richness was positively associated with vegetation height, evenness, and colourfulness suggesting that these are cues for estimating species richness. The accuracy of estimates varied, but respondents with higher levels of eco-centricity were more accurate than people who were less connected to nature

Plant species or flower colour diversity? Identifying the drivers of public and invertebrate response to designed annual meadows

© 2018 The Authors There is increasing evidence of the benefits of introducing urban meadows as an alternative to amenity mown grass in public greenspaces, both for biodiversity, and human wellbeing. Developing a better understanding of the meadow characteristics driving human and wildlife response is therefore critical. We addressed this by assessing public and invertebrate response to eight different annual meadow mixes defined by two levels of plant species diversity and two levels of colour diversity, sown in an urban park in Luton, UK, in April 2015. On-site questionnaires with the visiting public were conducted in July, August and September 2015. Invertebrate responses were assessed via contemporaneous visual surveys and one sweep net survey (August 2015). Flower colour diversity had effects on human aesthetic response and the response of pollinators such as bumblebees and hoverflies. Plant species diversity, however, was not a driver of human response with evidence that people used colour diversity as a cue to assessing species diversity. Plant species diversity did affect some invertebrates, with higher abundances of certain taxa in low species diversity meadows. Our findings indicate that if the priority for sown meadows is to maximise human aesthetic enjoyment and the abundance and diversity of observable invertebrates, particularly pollinators, managers of urban green infrastructure should prioritise high flower colour diversity mixes over those of high plant species diversity. Incorporating late-flowering non-native species such as Coreopsis tinctoria (plains coreopsis) can prolong the attractiveness of the meadows for people and availability of resources for pollinators and would therefore be beneficial

Plant selection for rain gardens : response to simulated cyclical flooding of 15 perennial species

Plant selection for rain gardens can be complicated, as cyclic flooding and a gradient of moisture level are expected in the depression structure of a rain garden. However, few studies to date have quantified how plant establishment is affected by rain garden moisture dynamics. This study investigated tolerance of 15 candidate perennial species, which experienced flooding cycles consisting of 1-day and 4-day inundation and draining phases. In this study, detection of species suitability using survival and growth measurements coupled with the stress indicator (i.e. chlorophyll fluorescence) provided a valid framework for wider use in plant selection for rain gardens. The methodology is also confident in predicting the possible placing in different plant moisture zones. All species survived the cyclic flooding treatments and grew to their maximum. Photosynthesis and physical growth in only a few candidate species (e.g. Amsonia tabernaemontana var. salicifolia, Gaura lindheimeri, Sanguisorba tenuifolia ‘Purpurea’ and Thalictrum aquilegifolium) tended to be inhibited by treatments adopting 4-day cyclic flooding, whilst tolerance to 1-day cyclic flooding was clearly demonstrated in most species. Analysis suggests that most species assumed to withstand infrequent to periodic inundation, such as Iris sibirica, Filipendula purpurea and Miscanthus sinensis, are resilient species and are sensible for use in a wider range of rain garden moisture conditions from damp depression bottom to dry margin. Species assumed to be intolerant of inundation such as Gaura lindheimeri may be successful in the rain garden environment, but they are recommended for the dryer zones

Urban meadows as an alternative to short mown grassland: Effects of composition and height on biodiversity

There are increasing calls to provide greenspace in urban areas, yet the ecological quality, as well as quantity, of greenspace is important. Short mown grassland designed for recreational use is the dominant form of urban greenspace in temperate regions but requires considerable maintenance and typically provides limited habitat value for most taxa. Alternatives are increasingly proposed, but the biodiversity potential of these is not well understood. In a replicated experiment across six public urban greenspaces we used nine different perennial meadow plantings to quantify the relative roles of floristic diversity and height of sown meadows on the richness and composition of three taxonomic groups – plants, invertebrates and soil microbes. We found that all meadow treatments were colonised by plant species not sown in the plots, suggesting that establishing sown meadows does not preclude further locally determined grassland development if management is appropriate. Colonising species were rarer in taller and more diverse plots, indicating competition may limit invasion rates. Urban meadow treatments contained invertebrate and microbial communities that differed from mown grassland. Invertebrate taxa responded to changes in both height and richness of meadow vegetation, but most orders were more abundant where vegetation height was longer than mown grassland. Order richness also increased in longer vegetation and Coleoptera family richness increased with plant diversity in summer. Microbial community composition seems sensitive to plant species composition at the soil surface (0–10 cm), but in deeper soils (11–20 cm) community variation was most responsive to plant height, with bacteria and fungi responding differently. In addition to improving local residents’ satisfaction, native perennial meadow plantings can produce biologically diverse grasslands that support richer and more abundant invertebrate communities, and restructured plant, invertebrate and soil microbial communities compared with short mown grassland. Our results suggest that diversification of urban greenspace by planting urban meadows in place of some mown amenity grassland is likely to generate substantial biodiversity benefits, with a mosaic of meadow types likely to maximise such benefits

“Not in their front yard” The opportunities and challenges of introducing perennial urban meadows: A local authority stakeholder perspective

© 2017 The Authors The growing evidence base for the benefits for people and wildlife of nature-based solutions to managing urban green infrastructure lacks research investigating land manager perspectives on their implementation. To address this gap, we explored UK local authority manager perceptions of the challenges and opportunities of introducing perennial urban meadows to prioritise biodiversity and aesthetics. This was co-produced as an experiment in urban greenspaces with Luton Parks Service and Bedford Borough Council 2013–15. We conducted semi-structured interviews with the eight stakeholder managers involved to identify key factors impacting on the perceived feasibility of future urban meadow establishment in other areas. All managers identified three dominant factors (aesthetics and public reaction, locational context, and human resources and economic sustainability). Additional factors (local politics, communication, biodiversity and existing habitat and physical factors) varied in importance according to personal values and managerial role. Support for future meadow introduction and a desire to overcome the economic challenge of the disposal of meadow arisings were related to manager biocentricity. Managers were aware of changing public values leading to increasing acceptance of a messier urban aesthetic. They perceived perennial meadows as a realistic alternative to amenity mown grass that in specific contexts could increase local biodiversity and enhance aesthetics if implemented in consultation with the public and local councillors. Our findings have relevance for the wider implementation of such nature-based solutions to urban GI management: Changes in management practice such as the introduction of perennial meadows have significant political, strategic, economic and practical implications and cannot be viewed purely as a technical challenge

Biodiverse perennial meadows have aesthetic value and increase residents’ perceptions of site quality in urban green-space

We used photo-elicitation studies and a controlled perennial meadow creation experiment at ten urban green-spaces in southern England (five experimental sites and five control sites) to assess green-space visitors’ responses to urban meadows. Multiple meadows, which varied in their structural diversity (height) and plant species richness, were created at each experimental site. Photo elicitation demonstrated that meadows were generally preferred to herbaceous borders and formal bedding planting. Moreover, our experimental meadows had higher preference scores than a treatment that replicated mown amenity grassland, and meadow creation improved site quality and appreciation across a wide range of people. Meadows that contained more plant species and some structural diversity (i.e. were tall or of medium height) were most preferred. The magnitude of these preferences was lower amongst people that used the sites the most, probably due to a strong attachment to the site, i.e. sense of place. People with greater eco-centricity (i.e. those who used the countryside more frequently, had greater ability to identify plant species and exhibited more support for conservation) responded more positively to meadow vegetation. Crucially a wide range of respondents was willing to tolerate the appearance of meadows outside the flowering season, especially when provided with information on their biodiversity and aesthetic benefits and potential cost savings (from reduced cutting frequencies). Re-designing urban green-spaces and parks through the creation of species rich meadows can provide a win–win strategy for biodiversity and people, and potentially improve connections between the two

Urban meadows as an alternative to short mown grassland: effects of composition and height on biodiversity

There are increasing calls to provide greenspace in urban areas, yet the ecological quality, as well as quantity, of greenspace is important. Short mown grassland designed for recreational use is the dominant form of urban greenspace in temperate regions but requires considerable maintenance and typically provides limited habitat value for most taxa. Alternatives are increasingly proposed, but the biodiversity potential of these is not well understood. In a replicated experiment across six public urban greenspaces, we used nine different perennial meadow plantings to quantify the relative roles of floristic diversity and height of sown meadows on the richness and composition of three taxonomic groups: plants, invertebrates, and soil microbes. We found that all meadow treatments were colonized by plant species not sown in the plots, suggesting that establishing sown meadows does not preclude further locally determined grassland development if management is appropriate. Colonizing species were rarer in taller and more diverse plots, indicating competition may limit invasion rates. Urban meadow treatments contained invertebrate and microbial communities that differed from mown grassland. Invertebrate taxa responded to changes in both height and richness of meadow vegetation, but most orders were more abundant where vegetation height was longer than mown grassland. Order richness also increased in longer vegetation and Coleoptera family richness increased with plant diversity in summer. Microbial community composition seems sensitive to plant species composition at the soil surface (0–10 cm), but in deeper soils (11–20 cm) community variation was most responsive to plant height, with bacteria and fungi responding differently. In addition to improving local residents’ site satisfaction, native perennial meadow plantings can produce biologically diverse grasslands that support richer and more abundant invertebrate communities, and restructured plant, invertebrate, and soil microbial communities compared with short mown grassland. Our results suggest that diversification of urban greenspace by planting urban meadows in place of some mown amenity grassland is likely to generate substantial biodiversity benefits, with a mosaic of meadow types likely to maximize such benefits.N/

The dynamic landscape

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