Biodiversity Hotspots: Where Life ConcentratesDefinitionSee other references1Biodiversity hotspotA biogeographic region that has exceptionally high levels of species richness and endemism but is also under significant threat from human activity.A snapshot of diverse organisms across the Earth's surface.Biodiversity is spread unevenly; hotspots are regions with exceptional numbers of rare, endemic, and threatened species.They have very high species richness and are top priorities for conservation.Most lie in tropical biomes, where conditions favour diversity.NoteThe tropics hold the greatest biodiversity.Polar regions and deserts have low productivity and far fewer species.What Makes Biodiversity Unevenly DistributedClimate stability: consistent temperature and rainfall support survival and speciation.Primary productivity: high photosynthesis sustains complex food webs.Habitat complexity: varied microhabitats let many species occupy different niches.Evolutionary time: long-undisturbed regions have had more time to diversify.Isolation: geographic isolation promotes endemism and unique evolution.ExampleThe Amazon Rainforest alone contains roughly 10% of all known species.The World's Major Biodiversity HotspotsTypical flora and fauna of the main biodiversity hotspots.Conservation International recognises 36 biodiversity hotspots.Together they cover under 3% of land but hold over half the world's plant species and about 40% of vertebrates.Six major examples are:Madagascar and the Indian Ocean IslandsOver 90% of its species are endemic; threatened by deforestation.Deforestation threatens the ring-tailed lemur, baobab tree, and tomato frog in Madagascar.Western Ghats and Sri LankaVery species-rich, with many endemic amphibians and plants.Species-rich Western Ghats and Sri Lanka, home to the Colocasia plant and Indian pangolin.Indo-BurmaSpans Vietnam, Cambodia, Laos, and Myanmar; under heavy agricultural pressure.Indo-Burmese species such as the red panda and orchids in broadleaf evergreen forest.MesoamericaRainforests of Central America and southern Mexico with high endemism.Flora and fauna of the Mesoamerica hotspot.Caribbean IslandsHigh endemism; threatened by deforestation and hurricanes.Caribbean species such as the American flamingo, palm tree, and rock iguana.California Floristic ProvinceTemperate region with many endemic plants; pressured by urban expansion.California Floristic Province species such as the Joshua tree, California condor, and gray wolf.Tropical Biomes Are the Richest HotspotsMost hotspots lie between about 15°N and 15°S.Constant sunlight, high rainfall, and stable temperatures drive continuous productivity, rapid speciation, and complex interactions.The richest tropical systems include:Tropical rainforests, such as the Amazon, Congo, and Southeast Asia.Tropical coral reefs, such as the Indo-Pacific and Caribbean.Tropical dry forests and savannas, such as the Cerrado and Madagascar.Protecting Hotspots: Priority and ThreatsHotspots hold a huge share of species in a small area, so protecting them is a highly efficient use of conservation effort.They provide key ecosystem services: carbon storage, water regulation, and pollination.The main threats are deforestation and land-use change, intensified by climate change.In the Amazon, logging, agriculture, and mining are driving rapid forest loss.Active recallWhat defines a biodiversity hotspot?Name two factors that make biodiversity unevenly distributed.Why are most hotspots found in tropical latitudes?Name one biodiversity hotspot and a threat it faces.Why is protecting hotspots an efficient conservation strategy?
