Working closely with Environment North and Flanagan Consulting Group, Biotropica Australia has been providing all the environmental survey data required to assist the Queensland Department of Main Roads to develop the Preliminary Design for this AUD$90 million project. In order to control the negative effects posed by the linear barrier effect of the new road, Biotropica staff have been assessing the highway environment and developing wildlife management solutions. A number of rare and vulnerable species and habitats were located during Biotropica surveys, influencing the final design and construction methodology. This project has a number of innovative approaches to road design which should set new benchmarks for road construction in sensitive areas. A feature of the design will be an ‘over the canopy’ viaduct which will allow wildlife to cross beneath the road in complete safety. Biotropica Australia staff worked closely with colleagues from James Cook University to examine the effects of the viaduct on light and moisture and whether the forest below would tolerate the modified conditions. Our modelling showed that light would be sufficient to maintain the growth of most plants however an overhead irrigation system will be needed to provide simulated rainfall for the forest beneath which would otherwise remain dry. Interestingly, the German Department of Transport recently embarked on almost identical work and Biotropica Australia ecologist Lars Kazmeier visited the project in Germany in June 2008. Even more interesting was the observation that research in Germany generated very similar data and recommendations to those made by Biotropica Australia and James Cook University.
Wildlife underpasses and canopy rope bridges are also planned in a number of locations. The Cardwell Range provides habitat for endangered species including the Cassowary and Mahogany Glider, and underpasses and rope bridges will be used to allow their safer movement across the road. Rehabilitation and fencing will be strategically used to direct and attract wildlife to underpasses, and to re-instate aquatic connectivity for fish, reptiles and amphibians.
Biotropica Australia staff have also been working with landscape architects from Place Design Group to develop rehabilitation techniques for the road works post-construction. Once again, Biotropica Australia has developed innovative approaches to revegetate the large cuts and embankments resulting from construction. Using only local native species, the rehabilitation design will work to ensure the construction is merged into the surrounds as quickly and effectively as possible. Biotropica Australia’s expertise in tropical rehabilitation is well known and the company is involved in a number of Department of Main Roads projects where this expertise is required.