Infrastructure development with(out) ecological conservation: the Northern Forests in Istanbul

Large-scale infrastructure development that accompanies global urban transformation threatens biodiversity and ecosystems around the world. Transportation infrastructure, in particular, uniquely affects landscape structure and connectivity. However, spatially explicit, quantitative analyses of change in habitat configuration due to multiple, linked transportation infrastructure are rare. Here, we analyze how a new airport and new highway system altered the spatial pattern of forest habitats to the north of the Istanbul metropolitan region in the context of two-decade-long landscape change. We carry out a land-change analysis from 2000 to 2019. We then analyze the changes in the spatial patterns of various forest habitat types across the metropolitan region, within and in the vicinity of the airport site, and in a key biodiversity area (KBA) that the new highway passes through. New transportation infrastructure significantly altered the forest habitats. Ten percent of all forest cover was lost, a quarter of which due to the new transportation development. Overall and within the KBA, respectively, core forest habitat decreased by 20% and 16%; the share of isolated, highly fragmented, and edge habitats within the remaining forest increased by 7% and 8%. On the European side of the metro area, the last remnants of the connectivity between the western and eastern sections of the forests were lost. The degradation of the forest landscape has implications for the endemic biodiversity and ecosystem services relied on by the metropolitan area. Our findings inform landscape strategies to arrest these degradation trends. Such strategies can succeed if ecological conservation is integrated into planning and current highly centralized governance structure is reformed.

Automated summary

The study analyzed the impact of a new airport and highway system on forest habitats in the northern Istanbul metropolitan region. The new transportation infrastructure significantly altered forest habitats, leading to a loss of forest cover and decrease in core forest habitats. Changes in spatial patterns were observed, highlighting the importance of integrating ecological conservation into planning and reforming governance structures to address degradation trends.