Michael Henry is the author of Old-Growth Forest Walks. He is a botanist and forest ecologist who has spent over two decades studying, writing about, and working to conserve Ontario's old-growth forests. He compiled and maintains the list of Ontario's oldest trees; he designed and constructed the Blueberry Lake Ecology Trails in Temagami; he confirmed that the Jackson Creek forest in Peterborough is an old-growth forest; and he has worked to protect threatened old-growth forests within Algonquin Park, where he and Nate Torenvliet found unprotected forest over 400 years old. He is currently working on a book about old-growth forests in Ontario's Greenbelt. Michael has also worked as a natural builder and is lead author of the book Essential Natural Plasters: A Guide to Materials, Recipes, and Use.