If trees could speak, what would they say? Diana Beresford-Kroeger, an ecologist, botanist, author and Fellow of The Royal Canadian Geographical Society, says there is a language in the forest, a language she’s spent most of her career trying to explain. Beresford-Kroeger — who’s studied everything from classical botany to experimental surgery everywhere from Ireland to the United States and Canada — is a self-proclaimed “renegade scientist” who combines Western scientific knowledge with ancient Celtic wisdom to study forests.

A specialist in the chemistry of trees, much of her work is done in her own “lab,” a 65-hectare garden bursting with plants and endangered tree species outside her home in Merrickville, Ont. “I started collecting rare trees because I knew that they were all being cut down,” she says. “I thought, ‘This is a genetic library that’s being lost.’ ”

Although her latest book, The Sweetness of a Simple Life, focuses on how to live well, Beresford-Kroeger doesn’t stray far from her life’s work. She’s currently filming Ten Trees That Can Save the World, the documentary component of a larger project of the same name, which will include an international educational program, an interactive website and an app. Her hope is that the project can help educate people about the Earth’s last great forests and the role they play in providing protection, nourishment and oxygen to humankind. “I know that after me there will be all kinds of people on Earth, and if I can help protect them, they’ll learn to protect one another,” she says. “Great things can’t happen in one generation, but they can happen in two.”