Do outdoor recreation(hunting/fishing) help people understand nature more and are more likely to conserve it?

Zak hit the nail on the head. Hunters are by far the biggest contributors to outdoor conservation, without exception. Look into an organization like the Rocky Mountain Elk Foundation. (RMEF) every year they aquire thousands of acres of land nationwide for the sole purpose of conservation. The tag and license fees hunters & fisherman pay fund most of the fish and game departments of any given state.