A recent study conducted by scientists from the Wildlife Institute of India (WII) Dehradun, highlighted by the National Tiger Conservation Authority (NTCA), sheds light on the positive environmental impact of closing segments of highways for vehicular traffic.
The study focused on State Highway 33 passing through Nagarahole Tiger Reserve, comparing the biodiversity along stretches closed for different durations. The assessment aimed to evaluate the influence of the highway on the flora and fauna of Nagarahole Tiger Reserve. Researchers examined two segments of SH 33: one completely closed to traffic (decommissioned segment) and the other closed only for nighttime traffic (night traffic closed segment).
Findings from the study revealed a notable difference in biodiversity between the two segments. The decommissioned road segment closed for an extended period and exhibited higher tree species composition and richness compared to the stretch closed only for nighttime traffic. Conversely, shrubs and herbs displayed greater species richness in the night traffic closed segment. Researchers attribute this variation to the edge effect, wherein the transition zone between two different habitats fosters greater biodiversity.
The study highlighted the presence of invasive species such as Lantana and Eupatorium, which had a higher cover in the area devoid of traffic. This phenomenon was attributed to increased light intensity on the forest floor due to lower canopy cover in the decommissioned road segment, as well as heightened animal activity serving as seed dispersers. Wildlife researchers and conservationists emphasise the significance of such findings, advocating against infrastructure projects within national parks or protected areas. The outcomes underscore the importance of preserving natural habitats and highlight the potential benefits of restricting vehicular traffic in sensitive ecological zones.
The study provides valuable insights into the environmental impact of highway closures on biodiversity. It underscores the need for sustainable conservation practices and informed decision-making regarding infrastructure development in ecologically sensitive areas. “Any traffic is not good for forest areas, especially tiger reserves. No new linear project proposals inside forest areas should be sanctioned. We took up a study a couple of years back on the number of road kills on SH 33 and during our study, we counted nearly 800 wildlife, including keystone species, dying in road kill,” said Ramesh Belagere, a wildlife researcher at the Foundation of Ecology and Education Development.
