We need ants to survive, but they don't need us at all.
Prof. E. O Wilson, in How Our Health Depends on Biodiversity,
Chivian, E., Bernstein A., Center for Health and the Global Environment, Harvard Medical School, 2010
Biological diversity, or biodiversity, is the scientific term for the variety of life on Earth. It refers not just to species but also to ecosystems and differences in genes within a single species. Everywhere on the planet, species live together and depend on one another. Every living thing, including man, is involved in these complex networks of interdependent relationships, which are called ecosystems.
Healthy ecosystems clean our water, purify our air, maintain our soil, regulate the climate, recycle nutrients and provide us with food. They provide raw materials and resources for medicines and other purposes. They are at the foundation of all civilisation and sustain our economies. It's that simple: we could not live without these “ecosystem services”. They are what we call our natural capital.
Biodiversity is the key indicator of the health of an ecosystem. A wide variety of species will cope better with threats than a limited number of them in large populations. Even if certain species are affected by pollution, climate change or human activities, the ecosystem as a whole may adapt and survive. But the extinction of a species may have unforeseen impacts, sometimes snowballing into the destruction of entire ecosystems.
European diversity is unique, but the loss of biodiversity has accelerated to an unprecedented level in Europe and worldwide. It has been estimated that the current global extinction rate is 100 to 1000 times higher than the natural rate. In Europe some 42% of European mammals are endangered, together with 15% of birds and 45% of butterflies and reptiles. To list just a few examples, the Arctic fox, the Iberian lynx and the red squirrel are all under serious threat.