Who needs an arborist license? Anyone who performs arboriculture work for compensation in Maine must obtain an arborist license or work under the direct supervision of a licensed arborist. What is arboriculture work? Arboriculture work as defined for licensing purposes includes: -leaving the ground for pruning or trimming, installing cabling or bracing, -diagnosing and evaluating conditions of trees, -felling or taking down trees in developed areas For licensing purposes arboriculture work does NOT include: -planting and fertilizing, -stump grinding, -chipping, -house and wood lot clearing. Though these are also services that are provided for the customers needs.