It is the variety of life on Earth, in all its forms and all its interactions. If that sounds bewilderingly broad, that’s because it is. Biodiversity is the most complex feature of our planet and it is the most vital. “Without biodiversity, there is no future for humanity,” says Prof David Macdonald, at Oxford University. For many people living in towns and cities, wildlife is often something you watch on television. But the reality is that the air you breathe, the water you drink and the food you eat all ultimately rely on biodiversity. Some examples are obvious: without plants there would be no oxygen and without bees to pollinate there would be no fruit or nuts.