Northern Arizona University says a top forest restoration pioneer is retiring. The university says Wally Covington will retire in January after 45 years there as a professor of forestry and executive director of the Ecological Restoration Institute. In a written statement, NAU said Covington's contributions have had a big impact on current forest management and policy in the U.S., including the use of controlled burns and reforestation to keep forests healthy. When wildfires across the West grew in size and intensity, he became a vocal advocate for stepping up forest restoration. Northern Arizona University President Rita Cheng calls Covington among the school's “most distinguished researchers.”