The earth has an enormous variability in the life forms at various scales of ecological complexity. More people than ever are appreciating the essential goods and services derived from biodiversity. Unfortunately, the growing human population and their demands have risked the sustainability of this biodiversity. The loss and degradation of habitats, excessive exploitation of resources, pollution, the introduction of invasive species, and the effects of climate change are the primary drivers of biodiversity decline. All these threats are associated with directly or indirectly humans. This chapter focuses on the key threats to biodiversity within the Indian Siwalik ecosystem.