The document discusses biodiversity hotspots, which are regions with high levels of endemic species that have lost at least 70% of their original habitat. It identifies 34 biodiversity hotspots around the world that meet these criteria. The main threats to biodiversity include habitat destruction, climate change, habitat fragmentation, pollution, overexploitation, and disease. Conservation efforts aim to prioritize protecting threatened regions through establishing reserves and protected areas, providing incentives for conservation, using regulations and market-based tools, developing new conservation professionals and projects, and promoting ecotourism.