Road Reserves Research Articles

N2: reading, writing, walking the South African highway

This piece is drawn from a larger project that asks what it might mean to write a cultural history or “biography” of the longest highway in South Africa, the N2. Influenced by literature on the everyday, on infrastructures and the “infra-ordinary,” my approach pays attention to the highway as a material artefact. Who builds, maintains and manages it; who makes their life along it; what subcultures, lexicons and social behaviours can be read off it? Exploring the possibilities of creative non-fiction within the environmental humanities, the piece here unfolds as an exercise in psychogeography, or a deconstructed travelogue. While much travel writing about modern Cape Town describes a (motorised) journey from airport to city, here I reverse the gaze and proceed on foot from town to the airport along the hard shoulder of the N2. In doing so I try to understand the vexed relations between drivers and pedestrians in a divided city, and to conduct an “anthropology of the near” on the road reserve: perhaps the most visible but least contemplated part of the modern urban landscape.

Mainstreaming Green Infrastructure Elements into the Design of Public Road Reserves: Challenges for Road Authorities

Global warming poses particular challenges for urban areas due to the greater intensity of rainfall and issues of stormwater runoff, and the heat island effect generated by the reflection of the sun off hard surfaces, such as buildings and road pavements; for example, in Australian cities (i.e., Sydney), roads account for approximately 25% of all urban land use. The challenge for road authorities is to implement in road planning, design and implementation as the term infrastructure has appeared increasingly throughout the world in land management and planning. Despite these environmental challenges, traditional highway engineering practices use arguments regarding the economic inefficiencies of urban traffic congestion to justify the business case for road-widening schemes and new road construction projects with associated de-forestation and vegetation loss. An international literature review and site visits of best practice in Australia, Singapore, the U.K. and the USA is reported. A typical road authority project is described in Sydney, Australia, where the initial design concept to accommodate growth in all modes of transport was road widening and land acquisition, but the authors persuaded the local and state government authorities to consider other options to green the infrastructure, particularly opportunities to add trees and vegetation near the roadway, which provide the additional bonus of managing surface water runoff. From this general problem, the case for, and value to, road authorities to develop guidelines for project planning and implementation, are presented. The conclusions include ongoing research to formulate draft guidelines for governments based on a holistic approach to the planning and design of high-density urban development around transport nodes that includes principles.

Using historic maps and citizen science to investigate the abundance and condition of survey reference ‘blaze' trees

Large old trees often possess important biodiversity and heritage values. This study investigated the occurrence and condition of survey reference trees in a typical rural landscape in New South Wales. A community survey (citizen science) method, in conjunction with a systematic examination of historic maps, was conducted to locate reference trees for subsequent field survey of their biophysical attributes and statistical analyses. In a combined study area ~5000 km2, we found 81 old reference trees, where an estimated 1.3–2.6% of the original number remains. Tree blazes ranged from 14 to 140 years in age, where most were 120–130 years old, and predominately of the Eucalyptus species. Blaze age was strongly correlated with the thickness of bark overgrowth. Types of reference trees identified included several PM (permanent marker) trees, a cemetery marker, a trig station and 15 benchmark (BM) trees. Eleven BM trees located were related to 1928–1932 irrigation surveys and were previously undocumented. Many reference trees were found in minor road reserves or in conjunction with clumps of other large trees. Being a form of living heritage, our results show that survey trees are succumbing to the ravages of time.

Plant Species Diversity along Road Reserve in Kisumu County- Kenya

Plant Species Diversity along Road Reserve in Kisumu County- Kenya

Forging Continuing Bonds from the Dead to the Living: Gothic Commemorative Practices along Australia’s Leichhardt Highway

Forging Continuing Bonds from the Dead to the Living: Gothic Commemorative Practices along Australia’s Leichhardt Highway

Participatory Design of Public Spaces for Urban Agriculture, Rosario, Argentina

Urban agriculture is increasingly recognized for its potential contribution to more sustainable urban development. Urban agriculture includes the cultivation and raising, processing and marketing of food and non-food crops, medicinal and aromatic herbs, fruit trees, as well as animal products within urban and periurban areas. Urban agriculture positively impacts urban food security, local economic development, environmental management and community building. To reconcile the demands posed by urban growth with urban agriculture activities of high social and economic value, urban agriculture however should be included into land use planning and design, and regulated by municipalities, assuring its proper management and avoiding potential health and environmental risks. Open and green urban spaces could be designed for multifunctional urban agriculture and combine natural habitat, food production, educational, recreational and leisure activities. Such design processes would benefit from broad participation of urban planners and architects, urban farmers, citizens and slum inhabitants as to enhance ownership and engagement, more effectively use available local resources and give the process a higher credibility and wider outreach. This article shares the experience of Rosario, Argentina where the city planners and University staff collaborated with two low-income communities in the design and implementation of a multifunctional neighborhood park, public square and road reserve. A step-by-step participatory design process was followed: starting from initial visioning, defining and relating the various existing and multi-functional land uses desired, to elaborating the site plan, and agreeing on implementation procedures. The article briefly contextualizes the site and its inhabitants, illustrates the design process and the results achieved and highlights some of the problems encountered. Participatory design of open spaces for urban agriculture in Rosario- though a complex process- proved to have contributed to improving socio-economic and environmental conditions in the city, while also serving as a source of inspiration to other cities in the region.

Environmental, landscape and social predictors of native grassland loss in western Victoria, Australia

Understanding the causes, processes and ecological consequences of land use change is a conservation priority in fragmented, human dominated landscapes but is often difficult due to insufficient environmental and social data or data at different spatial scales. We assessed changes in the extent of relictual native grasslands in western Victoria, Australia, by comparing native grasslands recorded by targeted vegetation surveys in the 1980s and early 1990s, with those present in 2004. Of the 880 ha of native grassland recorded by the earlier surveys, approximately 225 ha were destroyed by 2004. The area of grassland on road reserves was reduced by 169 ha (36%), with 67 ha (32%) and 18 ha (14%) lost from private property and Crown land, respectively. However, due to incomplete surveys in 1984, the area of private native grassland destroyed is likely to have been severely underestimated. Bayesian logistic regression models determined that social factors had a greater influence on the probability of native grassland destruction than environmental variables (i.e. soil type, distance to stream). The conservation ranking of native grassland patches and the fire brigade area the patch was located in were found to be particularly important. These results highlight the destructive effect of altering roadside fire prevention techniques from controlled burning to herbicide spraying, but suggest that this change is due to a complex interaction of social, economic and cultural factors.

On Squatters, Settlers and Early Surveyors: historical development of country road reserves in southern New South Wales

Country roads are an important social, economic and ecological component of agricultural landscapes in many parts of New South Wales. Using the Lockhart Shire Council area as a case study, this paper describes how present-day rural road networks are a historical vestige of past land-use decisions; a collection of Travelling Stock Routes, pastoral boundaries of early squatters, rail reserves, county and parish boundaries, and an ad hoc collection of mostly 1 chain (20.12 m) roads surveyed during the late 1800s. Road reserves were allocated across the landscape at the discretion of early surveyors, so new land titles could access vital water resources. Nineteenth-century surveyors faced many difficulties in surveying the extent of NSW, sometimes resulting in misalignments which today give ‘character’ to many country roads. Road reserves were often surveyed 2 or 3 chains wide to allow for predicted usage and provide materials for road construction. In the 1870s, Travelling Stock Routes of varying widths from 1 to 80 chains wide (one mile) were gazetted, which often form an integral part of many country road networks. In this way, present-day conservation values of many road reserves is a direct legacy of land policies, administrators and surveyors on the landscape today.

Our roadside heritage

The South Australian road network has evolved in the period since European settlement to meet the travel demands of the community and the developments in the means of road transport. As a consequence many items with heritage signifi cance can be found in and about the road reserve and indeed in the road itself. This paper explores the nature of these [non-aboriginal] heritage items and reports on an audit undertaken for Transport SA identifying such items and assets within a portion of South Australia’s road network. The audit is assisting in their conservation and management. The development of the road network and technologies in South Australia is briefly outlined and the heritage audit process and the benefi ts derived from the audit described.

Response of Acacia species to disturbance by roadworks in roadside environments in southern New South Wales, Australia

Disturbances from road management activities are often considered to be a major threat to plants in roadside environments, however effects may not be deleterious to all plants. The post-disturbance response of three Acacia species with different life-history attributes was compared in four road reserves impacted by soil disturbance from grading activities. Recovery of acacias to grading was variable, however basal resprouting, root suckering and seedling emergence led to a 6.2% population increase for all road reserves combined. In two road reserves, there was significant resprouting of the facultative seeder A. decora, and 2 years after disturbance, resprouts reached mean heights of 71 and 74 cm. One year after disturbance, 71% of A. decora resprouts flowered and 49% also set viable seed, and there was a significant positive relationship between flowers produced and viable seed set. Similarly, 65% of resprouts of the facultative seeder A. montana flowered but only 10% set viable seed. In contrast, there was patchy seedling emergence of the obligate seeder A. pycnantha and to a lesser extent A. montana, and seedlings did not reach reproductive maturity 1 year after disturbance. Drought most likely reduced seedling numbers, as seedlings were only recorded in shaded road reserves, where additional water was applied from roadworks activities. Grading of roadside environments appears to favour plants with strong resprouting ability, and persistence of Acacia populations will depend on the timing of soil disturbances from grading activities in relation to species life-history attributes.

The influence of land-use history on roadside conservation values in an Australian agricultural landscape

We investigated the influence of land-use history on roadside conservation values in a typical agricultural landscape of southern New South Wales (NSW), Australia. Historical information on the development of rural road reserves was collated from recently digitised 19th and 20th century pastoral and parish maps, such as road-reserve age and original survey width, as well as data relating to locations of old fence lines, county or parish boundaries, previous reserves, stock routes and road re-alignments. Ordinal regression statistics showed that road-reserve age and road width were significant predictors of roadside conservation values. Importantly, analyses showed that the first roads surveyed during the pastoral era (1840–1860s) were often of lower conservation value than roads surveyed in the 1870s, when major clearing of these landscapes commenced. Most roads were surveyed at one-chain width (20.12 m); however, pre-1870s historic roads, traveling stock routes (TSRs) and county or parish boundaries were significantly wider, decisions that have indirectly led to higher present-day conservation values. In separate analyses, historical data also formed a useful model to predict the absence of short-lived shrub species. These results highlight the influence and prevailing imprint of historical land-use on current roadside conservation values.

The population ecology of the squirrel glider (Petaurus norfolcensis) within a network of remnant linear habitats

The geographic range of the squirrel glider (Petaurus norfolcensis) in south-eastern Australia largely corresponds with fertile soils highly suited for agriculture. As a consequence of extensive clearing for agriculture, the conservation of P. norfolcensis in south-eastern Australia is now reliant on a mosaic of many fragmented and isolated patches of woodland and forest. In this study, I investigated the population dynamics of P. norfolcensis in an agricultural landscape where most remnant woodland occurs as linear strips along roadsides, unused road reserves and watercourses. A total of 251 gliders were trapped 1343 times within the linear habitats between December 1996 and November 1998. Gliders were resident within the linear strips at 0.95–1.54 individuals ha–1, a density equal to, or greater than, that recorded elsewhere for the species in continuous forest. All adult females were reproductively active and the mean natality rate was 1.9 young per adult female per year. Overall, the population age-structure appeared to be stable. While currently supporting a stable, high-density population, the long-term viability of these remnants as habitat is not assured because roadside reserves are narrow, easily fragmented and subjected to a host of deleterious processes causing ongoing habitat loss and degradation.

How to use roads in the creation of greenways: case studies in three New Zealand landscapes

Roads have traditionally been taken for granted due to their economic and social significance as transportation and utility corridors. They can also have a significant impact on the environment by transversing areas of wildlife habitat, and are one of the most destructive elements in the habitat fragmentation process. This study analyses the degree to which the ‘greenway’ and ‘connectivity’ concepts can be applied in an integrated approach to managing road reserves and the adjacent landscape to facilitate the extension of ecological corridors and mitigate adverse environmental effects of the roading network. While the New Zealand landscape and road networks are currently managed independently, the study found that there is potential opportunity to use the New Zealand road network as greenways to achieve partial integration between conservation and land use systems. A coordinated approach between conservation managers, road construction and management authorities, local government, utility managers, landowners and others who have interests in roadside management is necessary if integration is to be successful. Changes are also needed in the design of roads within reserve areas so that road safety requirements are augmented by consideration of the character of the landscape matrix and the needs of species moving through the landscape.

Survey of private land and adjacent crown and road reserve in the upper watershed of Specimen Gully

Survey of private land and adjacent crown and road reserve in the upper watershed of Specimen Gully

Guidelines for the display of advertising signs within the road reserve in Brazil

This paper discusses the use of regulated advertising signs within the road reserve to obtain funds for the improvement of highway infrastructure and safety conditions. Laws presently either do not exist or fail to provide appropriate guidance. A review is included of published material, describing the approach used in different countries and providing technical, economic and political support for the guidelines proposed in this paper. These guidelines could provide public agencies with the necessary basic orientation for their implementation, and the conclusions emphasize the action which should follow such implementation.

Re-establishment and maintenance of indigenous vegetation in South African road reserves: R.L. Dawson & J.P. Van der Breggen, in: Nature conservation 2: the role of corridors, ed D.A. Saunders & R.J. Hobbs, (Surrey Beatty), 1991, pp 327–332

A deliberate effort is being made by the National Roads Department in South Africa to re-establish indigenous vegetation in road reserves. Topsoil containing seed of local species is replaced in the road reserve after construction. Indigenous grass species are preferred for inclusion in the basic hydroseeding mixture. In certain areas the hydroseeding operation is supplemented using seed of local shrub or heath (fynbos) vegetation which is harvested locally by hand, suction or brushcutting methods. Predominantly indigenous trees and shrubs are planted. Natural colonization by indigenous species from outside the road reserve is encouraged, where this does not conflict with traffic safety considerations. Invasive alien species are removed, and the heavy encroachment by native woody species is controlled. For the covering entry of the conference, see IRRD abstract no. 843352.

Roads, roadsides and wildlife conservation: a review: A.F. Bennett, in: Nature conservation 2: the role of corridors, ed D.A. Saunders & R.J. Hobbs, (Surrey Beatty), 1991, pp 99–117

Roads are transport corridors imposed on the environment by humans for the movement of people and materials. Road systems are extensive in length and in the area that they occupy, and they extend pervasively throughout most terrestrial landscapes and habitats. A review of published literature reveals five major impacts of road systems on wildlife: (i) Road reserves provide habitat for wildlife. Roadside vegetation has greatest value as a wildlife habitat when it comprises remnant or regenerated strips of indigenous vegetation. (ii) Roads, roadside habitats and the aerial space above roads can facilitate the movement of animals along the direction of the road reserve. (iii) Road reserves can act as a filter or barrier to the movements of wildlife through the landscape, thus dividing and isolating populations to varying extents. (iv) Roads are a source of mortality for wildlife. For some species, particularly those that are large, rare, or are regularly brought into contact with busy roads (e.g., migration pathways), road- kills can have a significant effect on conservation status. (v) Road systems are a source of biotic and abiotic effects on the surrounding landscape. The extensive area occupied by road systems and the ecological impact of roads on wildlife means that they are too important to be neglected in conservation planning. Wildlife conservation must receive thorough consideration in the planning, construction and on- going management of road systems. The reserved status of roads, their geographical extent and continuity, and their network structure provide valuable opportunities for retaining and expanding wildlife habitat in disturbed environments, and for restoring or enhancing continuity to natural elements in the landscape. However, wildlife managers and managers of road systems must investigate further and implement practical measures to reduce the isolating effects of roads that bisect natural environments, to minimize the mortality of animals on roads and to limit disturbance to the surrounding environment. For the covering entry of the conference, see IRRD abstract no. 843352.

South African road reserves: valuable conservation areas?: B.L. Dawson, in: Nature conservation 2: the role of corridors, ed D.A. Saunders & R.J. Hobbs, (Surrey Beatty), 1991, pp 119–130

The nature and extent of the South African road network is briefly described, with particular reference to servitude widths and the extent of the road reserve. The policies and attitudes of the various road authorities, with regard to road reserve revegetation and maintenance, are also presented. The results of a survey of road reserves undertaken through a number of different biomes and vegetation types are discussed. It was found that some South African road reserves do, in certain vegetation types, constitute valuable conservation areas, but that this is more fortuitous than the result of any deliberate policy. The vegetation types where this is the case are those where the adjoining native vegetation has been largely transformed by agricultural or other human activities. These areas tend to be categorized by having a flat to undulating topography, better quality soils, and moderate to good rainfall. For the covering entry of the conference, see IRRD abstract no. 843352.

The flora roads survey — volunteer recording of roadside vegetation in Western Australia: B.M.J. Hussey, in: Nature conservation 2: the role of corridors, ed D.A. Saunders & R.J. Hobbs, (Surrey Beatty), 1991, pp 41–48

The south-west agricultural region of Western Australia has 107,500 km of roads, many of which retain native vegetation on the roadside. Public concern for the preservation of wildflower drives led to the reservation of wide road reserves (up to 200 m) deliberately for flora conservation. Thus many roadsides retain a linear transect of the original vegetation and have important conservation value. Degradation, however, is continually occurring, often due to lack of knowledge of the resource leading to inappropriate management. To obtain preliminary data, a survey was designed to use volunteers to assess the conservation value of road reserves. This chapter outlines the techniques used and compares the results with other surveys -- professional and amateur -- in Australia, with regard to accuracy, quality of data, cost, value as a management tool and public involvement. It is shown that the use of volunteers to survey roadsides is a cost-effective way of obtaining data while at the same time raising community consciousness. For the covering entry of the conference, see IRRD abstract no. 843352.

Habitat corridors and the conservation of small mammals in a fragmented forest environment

At Naringal in south-western Victoria, Australia, clearing of the original forest environment has created an agricultural landscape dominated by grazed pastures of introduced grasses. Remnant forest vegetation is re-stricted to small patches of less than 100 ha in size, that are loosely linked by narrow forested strips along road reserves and creeks. Six native and two introduced species of small terrestrial mammal (< 2 kg) occur within this environment. The native mammals, being dependent upon forest vegetation, were less tolerant to forest fragmentation than were the introduced species that also persist in farmland and farm buildings. The native mammals displayed an increasing frequency of occurrence in successively larger size-classes of forest patches. Those species with the greatest body-weight were the most vulnerable to habitat loss. All species of small mammal occurred in narrow habitat corridors of forest vegetation on roadsides. The resident status, seasonal variation in relative abundance, patterns of reproduction, and movements of each species were monitored in two habitat corridors during a 25-month trapping study. The corridors were found to facilitate continuity between otherwise-isolated populations of small mammals in this locality in two ways: firstly, by providing a pathway for the dispersal of single animals between patches; and secondly, by enabling gene flow through populations resident within the corridors. The small size of forest remnants at Naringal, and the vulnerability of species with low population sizes, emphasize the importance of preserving a mosaic of numerous habitat patches that together will support regional populations of sufficient size for longer-term persistence. The continuity between remnant habitats that is provided by a network of habitat corridors is an essential, and critical, component of this conservation strategy.