From freshwater pearl mussels to dormice, lapwings to barbastelle bats, national parks are home to a diverse range of wildlife.
Protecting the biodiversity found in our family of 15 National Parks is an important part of what we do.
The International Year of Biodiversity took place in 2010, and many parks ran special schemes and projects to help protect or re-establish rare species.
Shortly afterward, the United Nations declared a 'new decade of biodiversity', which runs until 2020, and the hard work being carried out in our parks goes on.
Here's a snapshot of some of the species, plants and places our family of national parks help to protect.
Biological diversity - or biodiversity - is the name we give to the variety of life on our planet, the result of billions of years of evolution. It is the web of life - and we're an integral part of it.
So far, scientists have identified about 1.75 million species, mostly small creatures such as insects. In total there are probably more like 13 million species, though estimates range from three to 100 million.
As well as plants, animals and micro-organisms, biodiversity also includes genetic differences within each species - for example, different crop varieties and breeds of livestock.
Biodiversity also means the ecosystems in our deserts, forests, wetlands, mountains, lakes, rivers and agricultural landscapes.
In a word: humans. The loss of species has always occurred but the pace of extinction has accelerated dramatically as a result of human activity.
Based on current trends, an estimated 34,000 plant and 5,200 animal species - including one in eight of the world's bird species - face extinction.
The threats to species and ecosystems include:
We're a part of it - and we can't live without it.
Most of the oxygen we breathe comes from plankton in our oceans and the forests around the globe.
The fruit and vegetables we eat have been pollinated by bees. The water we drink is part of a huge global cycle involving clouds, rainfall, glaciers, rivers and oceans.
Our diet depends almost entirely on the plants and animals around us - from the grasses that give us rice and wheat, to the fish and meat from both wild and farmed landscapes.
If that's not enough to make us stop and think, the natural world also supplies us with: