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Why is biodiversity so important?

Food

Our natural environment provides us with food, medicine, fuel, clothes, timber, climate regulation, water purification, soil regeneration, nutrient cycling, waste recirculation and crop pollination, for free. Ecologists and economists estimate the monetary value of nature's services to society is at least $33 trillion each year.

Variety really is the spice of life: less diverse ecosystems are less productive and less stable. But just 30 crops supply about 90% of the calories in our global diet. And just 14 animal species make up 90% of the livestock raised globally. Since we depend on so few plant and animal species to supply us with food, we are vulnerable to environmental changes and crop diseases.

Medicines

We have identified and named about 270,000 species of plants. At least 1,650 known tropical forest plants could be grown as vegetable crops. This could reduce our reliance on the few crops grown today.

Nature provides medicines such as aspirin, heart stimulants, antibiotics, anti-malarial and cancer fighting compounds. About a quarter of all prescription drugs come from plants. Yet less than 1% of rainforest plants have been tested for their medicinal properties.

We need new antibiotics to protect us against infections because disease-causing bacteria such as the super-bug MRSA have evolved to become resistant to antibiotics currently in use. Scientists working on NERC's Marine and freshwater microbial biodiversity programme discovered a previously unknown organism in sediment beneath the ocean that has properties that seem to inhibit MRSA.

Phytoplankton, tiny floating plants, protect themselves against the damaging effects of the sun's ultraviolet rays using compounds that may prove very useful to the skincare industry. Scientists at the Plymouth Marine Laboratory are now working with Boots Company plc to develop the potential of these natural sunscreens for human skincare.

Natural cycles

Ecosystems drive the natural cycles that make the Earth habitable: these cycles rely on a huge number of species to operate effectively.

Energy cycle

Plants, bacteria and phytoplankton (tiny floating marine plants) photosynthesise, transforming energy from the sun into stored chemical energy. This is the foundation for virtually all food webs.

Water cycle

Forests catch, hold and recycle rainwater, moderating water flows. Plants absorb rainwater, and then release it back into the air. Wetlands and estuaries purify water and control flooding.

Carbon and oxygen cycles

Plants absorb carbon dioxide and release oxygen back into the air, creating a breathable atmosphere and contributing to climate stability. Complete knowledge of the carbon cycle is crucial for scientists trying to understand climate change.

Nitrogen cycle

Nitrogen is essential for plant growth. Bacteria living on some plant roots convert nitrogen from the atmosphere into a form the plant can use. Creatures feeding on these plants release nitrogen in their waste products. When the waste is broken down by micro-organisms the nitrogen is recycled back into the atmosphere.

Can we live without some species?

Yes. Scientists believe we can live without some species without major consequences - the natural background rate of extinction is about two species per year. The extinction of certain species could lead directly to the loss of additional plants, animals or microbes in a habitat. We need to understand how biodiversity works in order to better predict the effects of species loss.