Why biodiversity matters

Biodiversity has shaped human culture, and human communities have shaped biodiversity. It plays ecological, economic and scientific roles, and raises an ethical question.

Ecological role. Nothing in an ecosystem exists without a function: every organism takes what it needs and also gives something useful to others.

• Species capture and store energy, produce and decompose organic matter, help cycle water and nutrients, fix atmospheric gases and help regulate climate. These functions keep ecosystems working and people alive.
• The more diverse an ecosystem, the better its species survive adversity and attack, and the more productive it is. Losing species weakens its ability to maintain itself.
• Like a species with high genetic diversity, an ecosystem with high biodiversity adapts better to change: more variety, more stability.

Economic role. Biodiversity is a daily resource for all people.

• Crop diversity, also called agro-biodiversity, is a key part.
• It supplies food crops, livestock, forests, fish and medicinal resources, and raw material for food, pharmaceutical and cosmetic products.
• Seeing biodiversity only as a store of resources has also damaged it, and has caused conflicts over who owns and shares natural resources.

Scientific role. Each species gives clues to how life evolved and will evolve, and how life works, including our own place as one species among many.

Ethical role. Every species has an intrinsic right to exist; it is morally wrong to cause a species' extinction knowingly. The level of biodiversity is a good indicator of how well we live with other species, and it is part of many human cultures.

Example (new): farmers who keep bees near their orchards get more fruit, because the bees pollinate the flowers: one species doing unpaid work that people depend on.