Transportation and ecological corridors

Transportation corridors affect wildlife habitat, populations, and entire ecosystems. Habitat fragmentation due to transport infrastructure is receiving growing concern among ecologists and civil engineers. Much data has been gathered that gives evidence of the complex impact of infrastructure on wildlife and landscapes. Roads, railroads, and their traffic disrupt ecological processes; increase mortality in animals, lead to a degradation, loss and isolation of wildlife habitat, and cause a fragmentation of the landscape in a literal sense. Infrastructure affects nature in both direct and indirect ways: The physical presence of roads and railroads in the landscape creates new habitat edges, alters hydrological dynamics, and disrupts natural processes and habitats. Road maintenance and traffic contaminate the surrounding environment with a variety of chemical pollutants and noise. In addition, infrastructure and traffic impose dispersal barriers to most nonflying terrestrial animals, and vehicle traffic causes the death of millions of individual animals per year.

We can distinguish between five major categories of primary ecological effects

1. Habitat loss - Construction of roads and railroads always implies a net loss of wildlife habitat. The physical encroachment on the land gives rise to disturbance and barrier effects that contribute to the overall habitat fragmentation due to infrastructure.
2. Disturbance - Roads, railroads and traffic disturb and pollute the physical, chemical and biological environment and consequently alter habitat suitability for many plant and animal species for a much wider zone than the width of the road or railroad itself.
3. Corridor - Road verges and roadsides can however provide refuges, new habitats or serve as movement corridors for wildlife. These beneficial effects of infrastructure are a major challenge to planners and biologists, as management and design must be adapted to a wider landscape context.
4. Mortality - Traffic causes the death of many animals that utilize verge habitats or try to cross the road or railroad. Traffic mortality has been growing constantly over the years, but is considered as a severe threat only in few species. Collisions between vehicles and wildlife are also an important traffic safety issue.
5. Barrier - For most non-flying terrestrial animals, infrastructure implies movement barriers that restrict the animals' range, make habitats inaccessible and can finally lead to an isolation of populations. The barrier effect is the most prominent factor in the overall fragmentation caused by infrastructure.

The key to success is the adoption of an approach that allows the whole range of ecological factors operating across the landscape to be integrated within the planning process.

The problem of fragmentation is universal, therefore joint research and combined international efforts are required. To develop adequate tools for assessing, preventing and mitigating the negative ecological impact of infrastructure requires interdisciplinary work. A significant challenge to ecologists, infrastructure planners and civil engineers and other actors is the establishment of an ecologically adapted, safe and sustainable transportation infrastructure system and, of course, the involvement of users of the infrastructure in the process.

The political support is the foundation of the success in combating the problem of habitat fragmentation due to transportation infrastructure.
Following needs for the future:

• An ongoing exchange of knowledge through Europe is vital, because of the complexity and widespread nature of the problem. A systematic and uniform approach to collect information on mitigation techniques and measures is necessary.
• The disturbance effect created by infrastructure needs to be more widely studied and mitigated in order to minimise habitat degradation adjacent to infrastructure.
• Monitoring programmes to establish the effectiveness of mitigation measures are essential and need to be standardised. The cost of monitoring programmes should be included in the overall budget for infrastructure schemes.

The main challenge for European countries and whole world is to adapt the existing and future transportation infrastructure to produce an ecologically sustainable transportation system.

TRANSGREEN project aims to contribute in the environmentally correct development of the transport system in mountainous regions of the Danube Basin with a special focus on the Carpathian Mountains. This is done by improving planning frameworks and developing concrete environmentally-friendly and safe road and rail transport solutions taking into account elements of Green Infrastructure, in particular ecological corridors.

Innovative pilot actions are focused on ecological corridors crossed by EU TEN-T road and rail projects in the Carpathians. EU TEN-T is the European Commission Programme aimed to ensure "cohesion, interconnection and interoperability of the trans-European transport network". In TRANSGREEN, sharing experience and knowledge is of of great importance. An interdisciplinary partnership comprised of planners, economists, engineers, and ecologists integrates and apply their specific knowledge across the region and cooperate on developing Guidelines on integrated transport infrastructure planning, construction, management and monitoring, taking into account aspects of road safety and biodiversity conservation. We also work on methodologies for stakeholder participation processes, training modules on Environmental Impact Assessment with a focus on ecological corridors, and Catalogues of measures for each of the four pilot sites.

An intersectoral dialogue will be fostered at the policy level that seeks for mutual understanding and implementation of recommendations towards integrated transport infrastructure planning from the local to the transnational level including EU level.

Sources:
https://pdfs.semanticscholar.org/e4f6/ef89c1bcf7a98bbec7b0299965bf5f6c7883.pdf
http://www.iene.info/wp-content/uploads/COST341_final_report.pdf
http://www.interreg-danube.eu/approved-projects/transgreen

Last updated: August 2018

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