Whether you’re looking at tropical forests in Brazil, grasslands in California or coral reefs in Australia, it’s hard to find places where humanity hasn't left a mark. The scale of the alteration, invasion or destruction of natural ecosystems can be mindbogglingly huge. Thankfully, researchers, governments and everyday people around the world are putting more effort and money into conservation and restoration every year, but the task is large. How do you plant a billion trees? How do you restore thousands of square miles of wetlands? How do you turn a barren ocean floor back into a thriving reef? In some cases, the answer lies with certain animals – called ecosystem engineers – that can kick start the healing. We talk to three experts about how ecosystem engineers can play a key role in restoring natural places and why the human and social sides of restoration are just as important as the science.

Featuring Josh Larsen, associate professor in water science at the University of Birmingham in the UK, Dominic McAfee, a postdoctoral researcher in marine ecology at the University of Adelaide in Australia, and Andy Kliskey, professor of landscape architecture and Co-director of the Center for Resilient Communities at the University of Idaho in the US.

This episode was produced by Katie Flood. The executive producer is Mend Mariwany. Eloise Stevens does our sound design and our theme music is by Neeta Sarl. Full credits for this episode are available here. A transcript will be available soon. Sign up here for a free daily newsletter from The Conversation.

Further reading: 

• Beavers can do wonders for nature – but we should be realistic about these benefits extending to people
• Beavers are back: here’s what this might mean for the UK’s wild spaces
• Playing sea soundscapes can summon thousands of baby oysters – and help regrow oyster reefs
• Once the fish factories and ‘kidneys’ of colder seas, Australia’s decimated shellfish reefs are coming back