Arborists gain qualifications to practice arboriculture in a variety of ways and some arborists are more qualified than others. Experience working safely and effectively in and around trees is essential. Arborists tend to specialize in one or more disciplines of arboriculture, such as diagnosis and treatment of pests, diseases and nutritional deficiencies in trees, climbing and pruning, cabling and lightning protection, or perhaps consultation and report writing. All these disciplines are related and some arborists are very well experienced in all areas of tree work, but not all arborists have the training or experience to properly practice every discipline.