Biodiversity is a key to healthy communities. It provides vital services like clean air, water, and food security. It also regulates diseases and stabilizes the climate. Ecosystems with a high biodiversity have more resilience to stressors, such as drought or disease. This is because species interact with one another in complex ways—from apex predators to fungi that decompose dead organisms. For example, when American chestnut blight killed the trees in forests of eastern North America in the early 1900s, the ecosystem was able to recover because other types of trees filled the void.
In a world of 7 billion people, we need biodiversity to provide the resources we need to survive. This includes the plants and animals we eat, the fuel we burn and the building materials we use. We also depend on the ecosystem services that biodiversity provides, including water filtration, soil fertility and stability, pollination, pest regulation and carbon storage. Ecosystems that are weakened by biodiversity loss are less resilient to stressors and will be unable to deliver the services we need.
In addition, there is a growing body of evidence that biodiversity is necessary for human health. The chemical compounds that make up plants, fungi and animal species are a source of thousands of life-saving medicines. From anticancer drugs to aspirin, the vast majority of medical and pharmacological advances are based on a deeper understanding of biodiversity.