Species extinction is now occurring at a faster rate than at any time in Earth's history, while at the same time thousands of new creatures are being discovered, mostly in the world's forests.
How can children at home and in schools get their heads around this vast subject? We have some wonderful resources on the Guardian Teacher Network to provide a way in.
The perfect introduction for primary children (and beyond) is an animation made by and for children with the help of the conservation organisation WWF. This film crystallises pretty much all the issues involved.
2011 is the UN International Year of the Forests, and to celebrate, WWF launches the Big Forest Picnic project today, planning events all over the UK on 20 August.
The idea is to encourage people to celebrate their local woodland and to think about how important forests are.
You'll find a set of WWF's inspiring posters on forests and sustainability issues, together with key questions, activity ideas and background.
There's no doubt that wildlife imagery is an effective means of building environmental awareness. The team at ARKive library have produced some rich resources.
In Biodiversity Hospital, lower secondary students work in teams and learn how to balance the competing priorities for the conservation of an endangered species.
For the ultimate in inspiring images, look at some photographs taken by wild crested black macaque in the forests of Indonesia after they borrowed a wildlife photographer's camera.
Read an introduction on how scientists are working in the field to discover new species, including the 10cm Berthe's mouse lemur now named as the world's smallest known primate. Read about the newly discovered fungi now called SpongeBob SquarePants.