Hello and welcome to Ways to Change the World. I'm Christian Gary Murphy and this is the podcast

in which we talk to extraordinary people about the big ideas in their lives and the events that

have helped shape them. My guest this week has changed the way we think about trees.

Professor Susan Semard is Professor of Forest Ecology at the University of British Columbia

in Canada. She is author of the book Finding the Mother Tree and her work has influenced

other scientists but modern culture, popular art, James Cameron, the tree in the in the movie Avatar,

the Tree of Souls. A lot of that comes from her work which tells us that trees are not just

singular things that you can chop down with no consequence but communicate, help each other,

maybe even recognise their own offspring. Susan, welcome. Thank you. And you're here actually

because you're collecting the Q International Medal in London so congratulations on that.

Thank you. Thank you. It's a great honour. I mean, first of all, explain in better terms than

I just did what your work is really about. Well, I look at how connection is important in

forest. So like you said, we used to think of trees as just individuals that, you know, try to get

their needs met by competing for light water nutrients and trees with long known also form

symbiosis with fungi, a group of micro, fungi called mycorrhizal fungi. And this has been known

for quite a long time but it was here in the UK that Sir David discovered in the laboratory that

little seedlings could actually be connected together by these mycorrhizal fungi that they could

trade actually carbon. And so what I did as I asked, does this happen in the forests of Canada?

And in Canada, we have big forests, you know, big old growth forests with trees that can be 50 meters

tall. And I thought, wow, I wonder if this is also occurring in our forests. So I did some field

work, field studies in my doctoral research. And I discovered that actually these trees in these

forests will actually send carbon back and forth between them through these mycorrhizal networks

...