Steve Backshall, Chris Packham and Ella Al-Shamahi visit the Maldives, Iceland and Cambodia; Steve Backshall travels to the Maldives, an area facing significant challenges because of climate change.

Another three presenters visit people fighting to rebalance vulnerable habitats around the world. Liz Bonnin travels to California to learn about the increasingly invasive wildfires hitting the headlines. Scientists can see clear links between the fires, climate change, raised temperatures and an extended drought season. There is one crucial element that is key to a sustainable future in California: biodiversity.

The second year of the BBC's ambitious, seven-year, natural history project sees six presenters visit six of the planet's most threatened ecosystems to meet the people fighting to restore the earth's delicate balance.

The second year of a definitive seven-year diary, documenting the fight to save our planet's most threatened ecosystems. Six presenters meet the people fighting to restore the balance.