Bits and pieces: Forest fragmentation by linear intrusions in India

Linear infrastructure development is an important driver of forest fragmentation leading to habitat and biodiversity loss as well as disruption of critical ecosystem processes. The tropical forests of India are increasingly impacted by infrastructure development. Little quantitative information is available on the extent of fragmentation due to linear infrastructure on these habitats. Here, we quantified fragmentation due to linear infrastructure by studying forest structural connectivity. We compared the existing forest patch characteristics with a scenario that excluded all linear infrastructure. We classified forest patches into three different fragmentation categories that combined information on patch size, inter patch distance and percentage perforations. Results show that power-transmission lines and roads were the most common infrastructure features within forests. We found a 6% increase in the number of forest patches due to the construction of linear infrastructure. Forest patches 10,000 km(2) in size were severely affected and there was a 71.5 % reduction in the number of such patches. We found that 86 % of the existing forest patches are in the small (median patch size < 1 km(2)) and isolated (a median distance of 155 m) category. The density of linear infrastructure inside protected areas was similar to density in non-protected forested areas. Our results highlight the need to minimize the effects of fragmentation in the future by considering re-routing or bundling of infrastructure. When infrastructure is unavoidable, there is a need to mitigate their potential impacts. The results of this study have been made publicly accessible (https://indiaunderconstruction.com) to provide information on 'where' to avoid future linear infrastructure development and to make informed decisions which can lead to optimally designed local management plans.