Roadside Verges Research Articles

Study of the roadside vegetation in the Walloon region (South Belgium) and in particular in the Upper Ardennes: phytosociology, ecology, pedology

of PhD thesis Study of the roadside vegetation in the Walloon region (South Belgium) and in particular in the Upper Ardennes :phytosociology, ecology, pedology by Sandrine Godefroid Laboratoire de Botanique systematique et Phytosociologie, Universite libre de Bruxe/les, avenue Franklin Roosevelt 50, C.P. 169, B-1050 Bruxelles Key-words: roadvergesremnant semi-natural vegetationecological network -linear elementsArrhenatheriongrassland vegetation. Mots-des : bermes de routes vegetation semi-naturelle relictuelle reseau ecologique elements lineaires Arrhenatherionvegetation prairiale. The study of roadside vegetation in south Belgium was carried out with the help of 233 phytosociological releves scattered in 20 ecological sectors. The analysis has demonstrate that it was possible to appreciate the syntaxonomical position of the phytocoenosis by using the Braun-Blanquet system. The results have made conspicuous that roadside verges, as well communal, agricultural as motorways, are a refuge for precious relics of the ancestral vegetal landscape, which was fashioned by a rural population living in a subsistence economy and which characterised the rural landscape of south Belgium till the beginning of the 20th century. So, quite the contrary of a widespread idea, roadside phytocoenosis are not always characterised by the dominance of one or a small number of species without any distinct phytogeographic and syntaxonomic affinities. Our study has thus revealed a strong correlation between ecoand phytogeographic characteristics of a region and the differentiation and the sync horology of roadside vegetation. 26 syntaxa, corresponding to well known units of the Braun-Blanquet classification, have been identified and belong to the Mesobromion erecti (Braun-Blanquet & Moor 1938) Knapp 1942 ex Oberdorfer (1950) 1957, Xerobromion erecti (Braun-Blanquet & Moor 1938) Moravec in Holub et a/. 1967, Arrhenatherion elatioris W. Koch 1926, Polygono Trisetion jlavescentis Braun-Blanquet & Tiixen 1943 ex Marschall 1947 n. inv. Tiixen & Pre sing 1951, Molinion caeruleae W. Koch 1926, Lotio Potentillion anserinae R. Tiixen 1947, Agropyro Rumicion crispi Nordhagen 1940 em. R. Tiixen 1950, Thera -A irian R. Tiixen 1951, Call uno Genistion pilosae Duvigneaud 1944 and Aperion spicae-venti Tiixen in Oberdorfer 1949. D ow nl oa de d by [ 21 3. 12 9. 11 0. 38 ] at 0 8: 57 2 2 M ar ch 2 01 4

The incidence of exotic species following clearfelling of Eucalyptus regnans forest in the Central Highlands, Victoria

Abstract Invasion by exotic species following clearfelling of Eucalyptus regnans F. Muell. (Mountain Ash) forest was examined in the Toolangi State Forest in the Central Highlands of Victoria. Coupes ranging in age from < 1‐ to 10‐years‐old and the spar‐stage forests (1939 bushfire regrowth) adjacent to each of these coupes and a mature, 250‐year‐old forest were surveyed. The dispersal and establishment of weeds was facilitated by clearfelling. An influx of seeds of exotic species was detected in recently felled coupes but not in the adjacent, unlogged forests. Vehicles and frequently disturbed areas, such as roadside verges, are likely sources of the seeds of exotic species. The soil seed bank of younger coupes had a greater number and percentage of seeds of exotics than the 10‐year‐old coupes and the spar‐stage and mature forests. Exotic species were a minor component (< 1% vegetation cover) in the more recently logged coupes and were not present in 10‐year‐old coupes and the spar‐stage and mature forests. These particular exotic species did not persist in the dense regeneration nor exist in the older forests because the weeds were ruderal species (light‐demanding, short‐lived and short‐statured plants). The degree of influence that these particular exotic species have on the regeneration and survival of native species in E. regnans forests is almost negligible. However, the current management practices may need to be addressed to prevent a more threatening exotic species from establishing in these coupes and forests.

A 38‐year study of relations between weather and vegetation dynamics in road verges near Bibury, Gloucestershire

1 The Bibury long‐term data set contains information on annual fluctuations in the abundance of over 100 grasses and forbs in roadside verge vegetation over the period from 1958 to the present. Monitoring has been carried out every July by the same individual. The data set represents a unique long‐term record of the dynamics of a complete plant community. 2 Records for the most abundant taxa (including bare ground and litter) were used to determine the effect of climate variability on the year‐to‐year performance of the selected species. Residuals about the long‐term mean log biomass of each species (de‐trended where the species showed a significant increase or decrease in abundance over time) were correlated against indices of interannual climate variability. Plant and weather records were compared over 3‐month seasonal periods (March–May, June–August, September–November, December–February) or 6‐month seasonal periods (March–August, September–February), with time lags of 0, 1 and 2 years. 3 Principal components analysis (PCA) was used to formulate annual weather indices, using either conventional weather variables (temperature, rainfall and sunshine) or the Lamb catalogue of daily weather types. 4 Between 5% and 70% more correlations were observed than might be expected to occur by chance, depending on the season and the PCA index, indicating markedly non‐random plant–weather relationships. Total vegetation production was positively correlated with minimum spring temperature. The distribution of correlations was generally evenly distributed across the three lag periods. 5 In general, those species favoured by environmental stress or disturbance were promoted following warm dry springs and summers, whereas those favoured by more productive conditions were promoted following a wet growing season.

Memorials without location: creating heritage places

Moaz Azaryahu has considered the ways in which a tragic event can lead to the public adoption and redefinition of a place (Azaryahu 1996). In the aftermath of the assassination of Yitzhak Rabin, the importance of identification with place was clear. Fortunately, such defining occasions are rare, but when they do occur, the interaction of place and event is not always so readily identified. In late August 1997, the United Kingdom seemed for once truly united in an extraordinary outpouring of grief for the death of Diana, Princess of Wales. The suddenness and unexpected nature of the event left many commentators paralysed. Despite a full week of saturation coverage in the media, the lasting impres sion was of the remarkable way in which the event mobilized the public. Research carried out by the Department of Social Sciences at Nottingham Trent University found that the death and funeral of the Princess of Wales had a profound psychological im pact on the public; indeed, a third of the subjects interviewed 'showed symptoms indicating post traumatic stress' (Shevlin et al 1997, 1468). This cre ated a shared memory of significance, but is it possible to capture that feeling in a continuation of the remem brance? Azaryahu describes a 'process of sacralis ation' that occurred in Tel Aviv, creating a shrine of the location of the assassination of Yitzhak Rabin (Azaryahu 1996, 501). This event was securely located in place, occurring in a public square that was already dedicated to events of nation-building. This contrasts with the death of Diana, which produced powerful, but largely unlocated, shared memories. Can we hold and commemorate such memories, or is the formaliz ation around a sanctified location inevitable? Azaryahu explores the developing practice of creat ing spontaneous memorials at the scene of tragic events. However, in the case of Diana, death had occurred abroad; this was an event without a specific location at home. A place had to be found for the tributes, separated from the actual events. The first pictures shown were of flowers placed at the royal palaces in London: Kensington Palace, understand ably, as the home of Diana, to which she would return on her last journey; more surprising, perhaps, the unoccupied Buckingham Palace. But what of the other choices? Althorp House, where Diana grew up but had not lived for many years, has a clear, if removed, connection. The flowers also piled up in cathedrals and churches, outside civic buildings and on war memorials, even on roadside verges outside cemeter ies and other public places. People sought places in their local area to create memorials. In Ruddington, Nottinghamshire, a simple vase of white flowers backed by silver paper replaced the usual collection of children's toys in the window of the Post Office; the local branch of the British Legion unlocked the gates that normally bar access to the village war memorial, so that flowers could be placed on the steps. Of all these locations, the war memorial is perhaps the most perplexing choice. There may seem little connection between the death of a young woman in a car crash and the commemoration of the loss of young men in war. Most of our war memorials date from the slaughter of the First World War, although many were rededicated to include the sacrifice of the Second World War. Despite the indiscriminate nature of bombing and the involvement of women in war ser vice, most war memorials remain resolutely male and military. So why seek out such locations to commem orate the individual, peacetime death of a woman? The answer seems to lie in the nature of the experience of grief and commemoration. There is a striking connection with the original purpose of the First World War memorials, as explored by Catherine Moriarty. These monuments were consciously cre ated to provide a location at which the many bereaved families might focus their mourning, in the absence of the physical remains of their loved ones, many of whom were lost forever in the mud of the battlefields (Moriarty 1995). It may be extending the connection too far to suggest that people sought out these sites to mourn the absent Diana, but the war memorials provide a location where, for generations, people have gathered for shared commemoration. The people who left flowers for Diana may be

Importance of host plants for detecting the population diversity of Rhizobium leguminosarum biovar viciae in soil

Rhizobium leguminosarum bv. viciae was isolated over 3 y from legumes nodulated with dilutions of soils from arable fields and uncultivated roadside verge sites, and from nodules of resident host legumes when present at these sites. Isolates were characterised by RAPD-PCR confirmed with plasmid profiles. There were large variations in diversity between sites, but diversity was not affected by cultivation per se. Most sites showed very high diversity of RAPD profiles with few profiles being isolated on more than one occasion. However, all profiles of isolates from one site were identical in the first year, but the same profile was not found in the following 2 y.Profiles were not randomly distributed among individual plants or among host species. Different trap plants were usually nodulated by different profiles, suggesting that studies to examine diversity should use large numbers of trap plants and the isolation of rhizobia from few nodules per plant.

Investigating roadside verges

Roadside verges: places of refuge, sinks for pollutants, barriers to wildlife. How should they be managed? Roadside verges are complex ecosystems which need careful management. In the last 30 years policies towards management have changed. Tidy, mown embankments are no longer common and ecological arguments have begun to play a greater role in restoration plans. Approaches towards management are explored through a class-based, decision-making exercise, whereby A-level students take on the role of consultants approached by a local authority to landscape a stretch of verge beside a newly constructed road. The article also includes material useful as background research for an Scl investigation. The potential of the roadside verge for individual A-level fieldwork projects is also explored, although it is acknowledged that undertaking such work in many locations is too dangerous. Suggested topics include: a survey of colonization before restoration, an evaluation of a current restoration scheme, a study of plants under stress from de-icing salt, pollutants and wind, and a survey of roadside fauna.

Effect of a highway on ant (Hymenoptera: Formicidae) species composition and abundance, with a recommendation for roadside verge width

Species composition and relative abundances of ground-dwelling ants at various distances from a major urban highway in South Africa were sampled using pitfall trapping. Diversity, richness and evenness indices indicated differences between ant assemblages, with samples near to the highway (<4 m) having the highest species diversity, and farthest ones (32 m) having the lowest. As measured environmental variables did not explain much of the variation in the species spatial pattern, it appears that the ants were influenced mostly by interspecific competition and/or distribution of food resources, especially road kills. Pheidole megacephala was highly dominant at all sites and was negatively associated with several other species. This and other dominant species appeared to be influencing the abundance of the rarer ones. Dominance and high abundances of species in the genera Pheidole, Monomorium, Tetramorium and Paratrechina, along with the occurrence of certain grasses, indicated that the whole sampling area was disturbed. In a suburban setting, a narrow roadside verge (<4m) is probably adequate. However, for maximum diversity in rural areas, roadsides should be as wide as possible and also rich and heterogenous in native vegetation.

THE MANAGEMENT OF THE ROADSIDE VERGE ESTATE.

The British Trunk Road Network was created in 1936. In England, it is the responsibility of the Highways Agency, an executive branch of the Department of Transport (DoT), and has 6600 miles of trunk roads and motorways. Its roadside verge estate is home to a wide range of native plants and animals, and also functions as an engineering component. This paper relates the history of the roadside estate, and explains the criteria for its successful maintenance and development. In 1956, the Landscape Advisory Committee (LAC) was appointed to advise on the choice of routes for new trunk roads, and very quickly recommended the use of native plants for their inter-urban roadsides. The Forestry Commission was appointed as principal managing agent of the roadside estate in 1962. The roadside estate is a complex, unique and very varied linear environment, which native plants and animals have learned to use as a refuge from intensive farming and built development, despite its hostile features. The paper describes the features of the roadside verge estate today, its planting design and implementation, its establishment maintenance phase which lasts for three years after planting, its management and innovation, and its approach to sustainable design for the 21st century. Two appendices present its landscape objectives.

The spatial distribution of Borrelia burgdorferi-infected Ixodes ricinus in the Connemara region of County Galway, Ireland.

Studies were carried out in the Connemara area of County Galway in the west of Ireland in order to determine the abundance and distribution of the tick, Ixodes ricinus and the prevalence of its infection with Borrelia burgdorferi. The tick was very abundant locally, in particular when associated with cattle, sheep and enclosed red deer. Large numbers of ticks not only occurred on the pastures, but also on adjacent roadside verges. No infections with B. burgdorferi could be demonstrated when nymphal ticks were sampled from central areas of the pastures, suggesting that livestock and red deer are probably not significant reservoirs of the spirochaete. Small numbers of infected nymphal and adult ticks were associated with hedges, dry stone walls, the margins of woodland adjoining infested pastures and in woodland from which livestock were excluded. Woodmice (Apodemus sylvaticus) were most numerous in such habitats and the majority were infected with B. burgdorferi.

The vegetation of roadside verges with respect to environmental gradients in southern New Zealand

Abstract. A survey of the vegetation of roadside verges was made across the southern part of the South Island of New Zealand. Samples were taken at 10‐km intervals along selected roads providing a climatic range from the suboceanic conditions of the east coast into semi‐arid Central Otago, and from Central Otago through the Southern Alps to the hyper‐oceanic areas of high rainfall on the west Coast. The variation in the floristic composition is associated mainly with variation in rainfall, continentality, altitude, soil acidity, soil organic matter, and presence of forest. Sites in the arable and pastoral regions on the eastern side of the Southern Alps support a herbaceous vegetation consisting mostly of exotic species of European origin, with a few native grasses scattered through the drier and less fertile sites. A greater proportion of native species is found at higher altitudes. Roadside vegetation in the area of high rainfall to the west is characterized by indigenous ferns and woody species, although vegetation adjacent to cleared areas is more similar to that on roadsides adjacent to farmland on the east coast. The pattern of distribution of both native and exotic species is strongly related to altitudinal and climatic gradients, and the environmental responses of the exotic species are similar to those recorded in Europe. This suggests a colonization of all available sites by the exotic species, despite the relatively short time since their introduction to New Zealand, rather than an incomplete invasion.

The Ecology of House Mice (Mus Domesticus) in and Around Irrigated Summer Crops in Western New South Wales.

A 28-month live-trapping survey was undertaken to investigate the ecology of house mice in an irrigated summer cropping system in western New South Wales. Five broad habitat types were examined: refuge habitat (e.g. roadside verges), grazed dryland pasture, and the irrigated summer crops soyabeans, sorghum/maize and cotton. Mouse abundance in most habitats peaked around March-April in each year, and then declined to relatively low levels by the end of spring. Mice were always present in refugia but were often at very low numbers or absent from pasture and cotton. Very few mice were caught on paddocks used for summer crops during their fallow stage, but quickly appeared immediately following sowing. Of the summer crops, the maintenance of relatively high numbers of mice was greatest in soyabean crops. Breeding occurred in several habitats throughout much of the year but was generally greatest in October-March. Grazed pasture and cotton had the fewest breeding females and refuge habitat the most. These results are compared with other published studies, and their implications for management strategies are discussed.

Conservation value of roadside verges for stenotopic heathland Carabidae: corridors or refugia?

It has been shown that, in The Netherlands, sandy roadside verges may aid the survival of stenotopic Carabidae associated with open habitats such as heathland and sandy grassland. It is suggested that roadsides serve as ‘corridors’ linking heathland fragments, thus maintaining a metapopulation structure, which helps avoid regional extinction. However, a counter-argument is that verges encourage dispersal into unsuitable habitats, and function as ‘sinks’ in which individuals die without reproducing. The stenotopic species recorded from roadside verges but not in adjacent open habitats all had high powers of dispersal. The least successful dispersers were found only in open habitats and in verges closely connected to them. From this, the conclusion that verges function as corridors can be drawn. We reinterpret these data to suggest that stenotopic species were breeding on the roadside verges, and that they acted as refugia rather than corridors. We also present evidence from a roadside verge in the Breckland region of East Anglia, England. We show that many stenotopic species breed on the verge, which thus functions as a refugium. For Carabidae dependent on early successional habitats, survival may be more likely on disturbed roadside verges than on nature reserves in the absence of regular management disturbance.

Succession of ectomycorrhizal fungi in roadside verges planted with common oak (Quercus robur L.) in Drenthe, The Netherlands

In the period 1986–1988, sporocarps of ectomycorrhizal fungi were counted in 53 plots in roadside verges planted with common oak in Drenthe, The Netherlands, belonging to three vegetation types. Twenty five plots were Hypochaeris radicata-Quercus communities, comprising roadside verges in open landscapes on dry, acid, sandy soils, poor in nutrients. In each plot, the trees were even-aged but varied between 10 and 140 years. The relationship between tree age and numbers of ectomycorrhizal species and sporocarps was studied. The species composition of roadside verges was compared between young trees (10–20 years), medium-old trees (20–50 years) and old trees (50–140 years). The species composition in roadside verges in open landscape with old trees was also compared with the ectomycorrhizal fungi in two further different types of roadside verges with old oak trees, viz the Anthriscus sylvestris-Quercus type, comprising open to half-open plots on soil richer in nutrients, and the Mnium hornum-Quercus type, comprising shady plots surrounded by forest. The data reveal a distinct succession of ectomycorrhizal fungi with increasing tree age. The results are compared with data on succession of ectomycorrhizal fungi in forest stands. It is concluded that the succession cannot be modeled simply as suggested by some authors. Instead, changes in species composition and diversity showed much variation in relation to different environmental conditions. The factors relevant to the course of ectomycorrhizal succession are discussed. The concepts of early- and late-stage fungi are critically considered. It is concluded that this classification is not appropriate for the description of the ectomycorrhizal succession during stand development. A new, provisional classification of ectomycorrhizal fungi on the basis of their appearance during forest succession is proposed.

Succession of ectomycorrhizal fungi in roadside verges planted with common oak ( Quercus robur L.) in Drenthe, The Netherlands

Succession of ectomycorrhizal fungi in roadside verges planted with common oak ( Quercus robur L.) in Drenthe, The Netherlands

Corridor function of a road verge for dispersal of stenotopic heathland ground beetles carabidae

To reduce the effects of habitat isolation dispersal corridors between habitat fragments are often proposed. In this study the corridor function of a poor sandy roadside verge, adjacent to an open area of drift sand, was investigated for ground-dwelling arthropods. Three species of carabid beetles characteristic of this habitat, Pterostichus lepidus, Harpalus servus and Cymindis macularis, were marked and released at four different sites. Exchange of individuals of these species was recorded between the road verge and the open sandy area, and dispersal along the road verge was established. The rate of movement along the road verge was low compared to that in the open area. Sites with trees and narrow sites at the road verge had a barrier effect. Reproduction was recorded for two species at broad areas in the road verge. Under certain conditions (re) colonization of habitat areas by dispersal along a long, ribbon-like habitat might occur. For each species the specific features of such a corridor is discussed.

The composition of the carabid fauna on poor sandy road-side verges in relation to comparable open areas

In The Netherlands, the majority of heathlands and dry, unproductive grasslands have been brought into cultivation or afforested since the end of the 19th century. As a result, the original landscape has become highly fragmented. Nowadays, the heath habitat occurs in more or less isolated patches only. Many of these fragments show a small spatial variation in conditions. Ground-dwelling arthropods, with a low dispersal power and a specific preference for poor, sandy, open habitats, could disappear from such small fragments under the influence of temporarally unfavourable conditions. As recolonization from other fragments is often very difficult because of hostile surrounding areas, isolated small fragments that have lost their populations will remain unoccupied. The absence of some carabid species in such small, isolated fragments is thought to be the result of this situation. By introducing heathy corridors between such fragments, animals might be enabled to pass a hostile environment. This study shows that heathy road-side verges can possibly function as such a corridor. On the studied road-side verges, carabid species of poor sandy, open habitats were present, including the more rare species. Some species even found a better habitat at road-side verges than in adjacent poor sandy open areas. For other species the road-side verge seemed to be a more marginal habitat in which they occur only because of the presence of a suitable adjacent area. The distance to such an area, as well as the width of the poor sandy, open strip on the road-side verge seem to be important conditions for the occurrence of the latter species. In order to increase the survival chance in such a corridor, it is suggested that some wider strips or patches be created at the road-side verges, suitable for reproduction. In this way, road-side verges might contribute to a metapopulation structure by which species are better protected against regional extinction.

Water flux and energy use in wild house mice (Mus domesticus) and the impact of seasonal aridity on breeding and population levels.

Water turnover rate (WTR), urine concentration and field metabolic rate (FMR) were examined in house mice, Mus domesticus, permanently inhabiting roadside verge areas and seasonally invading crops in semi-arid wheatlands in South Australia. FMR was approximately proportional to body mass0.5 and mean values varied from 4.8 ml CO2 g-1h-1 (2.9 kJ g-1d-1) in autumn and winter, to 7.0 ml CO2 g-1h-1 (4.2 kJ g-1d-1) in maturing crops during spring. WTR was independent of body mass, indicating that larger mice were selecting a diet containing moister foods. WTR was low in summer and high in winter, and in mice from crops varied from 165 ml l-1 body water d-1 (122 ml kg-1d-1) to 1000 ml l-1d-1 (725 ml kg-1d-1). Seasonal changes in WTR were less extreme on the roadside, where a greater diversity of food was available. In the crops, breeding occurred throughout summer during two of three years, but the population increased only in the one summer when mice had marginally higher WTR. On the roadside breeding and population growth were continuous during summer, except in a drought year. Avcrage urine concentration was inversely related to WTR, and varied from 2.0 to 4.8 Osm l-1. The data indicate that the water conserving abilities of mice equal those of many desert rodents. The water conserving abilities of mice living in crops during summer were fully extended, and in some years aridity limited breeding success and population levels. The degree of moisture stress to which mice are exposed during summer appears to depend not only on rainfall but also on other factors such as availability of food and shelter, and the level of weed infestation in crops.

GUIDELINE FOR THE EFFICACY EVALUATION OF GROWTH REGULATORS

This guideline gives instructions for conducting trials on the efficacy evaluation of growth regulators used to retard the growth of grass in situations such as amenity grassland, roadside verges, grass cover in orchards, but not pasture grassland or grass seed crops. For the case of grass seed crops, see EPPO Guideline no. 144 for Efficacy Evaluation of Growth Regulators for Reduction of Lodging in Cereals.

Occurrence of entomopathogenic nematodes (Rhabditida: Steinernematidae and Heterorhabditidae) in British soils

SUMMARYSoil from 403 hedgerow, roadside verge, woodland, heathland or field sites was assessed for presence of entomopathogenic rhabditid nematodes with aGalleria larva baiting technique. Steinernematids were recovered from 48 % of the sites but only one site yielded Heterorhabditis sp. The species recovered most frequently was Steinernema bibionis (Bovien). Another unidentified Steinernema sp. was also isolated. Prevalence of steinernematids in the different types of habitat formed continuum so that roadside verges harboured them most often while heathland sites yielded them least often. Mean soil temperatures at 5 cm were about 15 °C in fields and verges, 13 °C in hedgerows and heathland and 12 °C in woodland. Prevalence of the nematodes varied in different parts of Britain and was influenced by soil type. They were associated with calcareous soils, especially those with a calcareous subsoil horizon. Soils which are periodically or seasonally water-logged were suitable. Soils enriched by humus and hence high in organic matter frequently harboured the nematodes and some suitable soils had significant clay contents or subsoils high in clay. It appears that the two steinernematids are relatively unspecialized species, occurring in diverse habitats and soil types and are adapted to cooler temperatures.

Survey of 15 sites over 28 months for entomopathogenic nematodes (Rhabditida: Steinernematidae)

SUMMARYThe presence of entomopathogenic nematodes in soil from 15 sites on 10 sampling occasions over a period of 28 months was documented. Sites were chosen to represent habitats classified as heathland, hedgerow, roadside verge, pasture or woodland. Bioassays utilized Galleria larvae and most of the nematodes obtained were identified asSteinernema (= Neoaplectana) bibionis (Bovien). A sibling species which fails to interbreed with S. bibionis was also found at 2 of the sites. Bioassays were at 15 and 20°C and there was no significant difference in the results at these temperatures. There was no evidence for seasonality in the presence of the nematodes and at 2 sites they were found on every sampling occasion. Otherwise, sites converted unpredictably from positive to negative or negative to positive over the 28-month sampling period.