Urban expansion threatens forest biodiversity on private lands in Nirjuli, Arunachal Pradesh, Northeast India

Abstract A forest patch in Nirjuli, Papum Pare district, Arunachal Pradesh, supports remarkable biodiversity, including 11 species endemic to Northeast India and five species newly recorded from this area. Over the past two decades, rapid urbanisation and expansion of human settlements have driven significant land use and land cover (LULC) changes, leading to deforestation, habitat loss, and fragmentation of critical microhabitats. Forest cover declined from 17.46 km2 in 2004 to 14.52 km2 in 2024, representing a net loss of 2.94 km2 (16.83%), with 3.13 km2 (15.9%) of forest converted to built-up areas. Such transformation threatens endemic and ecologically valuable species, many of which occur outside formal protected areas. This study highlights the urgent need for conservation interventions, particularly ex-situ approaches, to safeguard plant diversity in urban-proximate forests. Protecting these microhabitats is essential for maintaining regional biodiversity, preventing species loss, and promoting sustainable coexistence between expanding human settlements and fragile ecosystems.