VICTORIA, B.C.-As another year of long-burning, uncontrolled wildfires decimates portions of the U.S. and Canada-even threatening the world's oldest trees, located in California-one expert says North American authorities need to take some guidance and advise from Native Americans.

"We're not burning anywhere near as much as we should," fire ecologist and noted burn boss Bob Gray, from Chilliwack, B.C., told The Canadian Press. Gray consults for local, provincial, state and tribal governments across Canada and the United States.

Gray has been a part of a U.S. Forest Service research team stu...