Teamster Bub Pierce directs a team of Belgians to haul a freshly cut pine tree from a lot Thursday in South Gardiner.  West Gardiner contractor Steve McGee employed the pulling horses, which compete at fairs across Maine, to twitch pine from a house lot he was hired to cut.  “We all need exercise,” McGee said while felling a tree. “It’s good for the environment and it produces revenue.” Pierce, who trains the horses for McGee, agreed. “They need to learn how to work before they learn how to compete,” he said.