Minor rural road networks: values, challenges, and opportunities for biodiversity conservation

Roads corridors are a conspicuous part of most landscapes, which are gaining greater recognition for their role in nature conservation. However roads cause wildlife mortality, alter water and nutrient flows, change local microclimatic conditions, act as vectors for weeds and pest animals, and have other far-reaching effects. Not surprisingly, there is much attention from both road and conservation managers to lessen these impacts, with an emphasis on developing solutions to mitigate the barrier effects of major roads to wildlife movements. However in many anthropogenic landscapes, road corridors can also provide key habitat and connectivity for local biodiversity. In particular, where traffic volumes are low, minor roads often provide critical habitat and refuge for many native species. Knowledge of the ecology and biodiversity conservation values of minor rural road verges has been underpinned by studies in various contexts, such as sunken roads, field margins and hedgerow networks in Europe, to stock routes in Spain and Australia. Despite their different histories and management constructs, important commonalties have been highlighted in terms of their biodiversity values, and the factors which influence these values. As such, minor rural road networks can be vital in providing connected, functioning ecosystems within rural landscapes. The importance of vegetated minor rural road networks will only become more pressing with future climate change. In Australia, road management authorities are tasked with the dual roles of maintaining road transport needs (i.e. priorities for road maintenance and safety concerns), whilst maintaining the environmental values of roads. This paper reviews the biodiversity values of minor rural roads, discusses the challenges and constraints in managing these values, and describes the case of identifying historic roads as an example of enhancing conservation management of these important habitats in rural landscapes.