Genes, species, ecosystems, evolution, habitats, ecosystem services, conservation, extinction risk, land use, climate change, invasive species, and human well-being
Biodiversity
Biodiversity is the variety of life, from genetic differences within species to the many species and ecosystems on Earth. It supports food, clean water, medicine, climate resilience, culture, and the ecological processes that make human and nonhuman life possible.
What biodiversity means
Biodiversity means biological variety at several levels. It includes genetic diversity within a species, the number and mix of species in a place, and the diversity of ecosystems such as forests, grasslands, wetlands, reefs, farms, rivers, and deep-sea habitats. It is not only a count of species, but also the differences and relationships among living things.
Genes, species, and ecosystems
Genetic diversity helps populations adapt to disease, climate shifts, and other changes. Species diversity describes the range of organisms living in an area and how common or rare they are. Ecosystem diversity captures the variety of habitats and ecological communities. These levels connect: genes shape species, species build ecosystems, and ecosystems influence evolution.
How biodiversity supports life
Biodiversity helps ecosystems function. Plants produce oxygen and food, fungi and microbes recycle nutrients, insects and other animals pollinate many crops and wild plants, wetlands filter water, and predators can help keep food webs balanced. These benefits are often called ecosystem services, but they are also relationships that living systems depend on.
Why places differ
Biodiversity is unevenly distributed. Tropical forests, coral reefs, wetlands, and some islands can hold many species, including species found nowhere else. Climate, geology, isolation, disturbance, evolutionary history, and human land use all shape what lives in a place. A small habitat can be globally important if it protects rare or unique life.
Main causes of loss
Biodiversity declines when habitats are converted, fragmented, polluted, overharvested, or altered faster than species can adapt. Climate change shifts temperatures, rainfall, fire patterns, ocean chemistry, and species ranges. Invasive species can disrupt local food webs. These pressures often combine, so protecting biodiversity usually requires more than one solution.
Measuring biodiversity
Scientists measure biodiversity with field surveys, genetic tools, museum records, satellites, environmental DNA, acoustic sensors, and community observations. They track species richness, abundance, population trends, habitat quality, genetic variation, and ecosystem function. No single number captures everything, so good assessments use several measures together.
Conservation choices
Conservation can protect habitats, restore degraded ecosystems, reduce pollution, manage harvests, control invasive species, connect fragmented landscapes, and support Indigenous and local stewardship. Protected areas matter, but biodiversity also depends on farms, cities, rivers, coasts, and working lands being managed in ways that leave room for other life.
Why it matters
Biodiversity matters because human societies are embedded in living systems. Losing biodiversity can weaken food security, water quality, disease regulation, climate resilience, cultural heritage, and options for future discovery. Protecting it is not only about saving distant wildlife; it is about keeping the fabric of life stable enough for communities to thrive.