Implications of large-scale infrastructure development for biodiversity in Indonesian Borneo

Indonesia is embarking on an ambitious relocation of its capital city to Kalimantan, Borneo, bringing with it major urban and road infrastructure. Yet, despite being one of the world's most biologically diverse regions, the potential im-plications of this development for wildlife have yet to be fully assessed. We explored the potential impacts of the capital relocation, and road expansion and upgrades to critical habitat for medium-large mammals (>1 kg) using camera trap data from 11 forested landscapes. We applied Bayesian multi-species occupancy models to predict community and species-level responses to anthropogenic and environmental factors. We extrapolated spatial patterns of occupancy and species diversity across the forests of Kalimantan and identified critical habitats as the top 20th percentile of oc-cupancy and species richness values. We subsequently overlapped these critical habitat layers with infrastructure impact zones to estimate the area that could potentially be affected by direct or secondary impacts. At both the com-munity and species-level, distance to primary roads had the strongest negative influence on habitat-use. Occupancy was also influenced by forest quality and multidimensional poverty conditions in adjacent villages, demonstrating the sensitivity of biodiversity to socio-ecological pressures. Less than 1 % of the critical habitat for the threatened mam-mal community lay within the direct impact zone (30 km radius) of the capital relocation. However, approximately 16 % was located within 200 km and could potentially be affected by uncontrolled secondary impacts such as urban sprawl and associated regional development. The often-overlooked secondary implications of upgrading existing roads could also intersect a large amount of critical habitat for lowland species. Mitigating far-reaching secondary im-pacts of infrastructure development should be fully incorporated into environmental impact assessments. This will pro-vide Indonesia with an opportunity to set an example of sustainable infrastructure development in the tropics.

Automated summary

Indonesia is relocating its capital to Kalimantan, Borneo, and this development may have potential impacts on wildlife. Using camera trap data from 11 forested landscapes, the study analyzed the effects of the capital relocation and road expansion on medium-large mammals' habitat. It was found that distance to primary roads, forest quality, and poverty conditions influenced habitat use and biodiversity. The study highlights the need to consider and mitigate both direct and secondary impacts of infrastructure development on critical habitats.