Biodiversity and Its Value

Biodiversity exists at three interconnected levels. Genetic diversity is the variation in genes within a species—it allows populations to adapt to changing conditions and resist diseases. Species diversity is the variety of species in a given area; tropical rainforests may contain 300 tree species per hectare compared to 10-15 in a temperate forest. Ecosystem diversity is the variety of habitats, communities, and ecological processes across a landscape—a region containing forests, wetlands, grasslands, and rivers has higher ecosystem diversity than one dominated by a single habitat. All three levels contribute to the resilience and productivity of the biosphere.