National Arborist Association

The National Arborist Association (NAA), now known as the International Society of Arboriculture (ISA), is a professional organization dedicated to promoting excellence in tree care. It provides education, certification, and standards to ensure that trees are maintained healthily and safely. Arborists—specialists in the planting, pruning, and removal of trees—use these resources to improve urban and rural landscapes responsibly. The organization also advocates for sustainable practices, local regulations, and ongoing research, helping communities and tree care professionals work together to protect and enhance the environment.