An arborist or tree surgeon is a professional who manages and maintains trees (generally in an urban environment). This can include planting, pruning, structural support, the treatment of disease, insect, or abiotic disorders, lightning protection, and tree removal. It also can include planning, consulting, report writing and even legal testimony. Because trees provide many benefits to the landscape and to people, but they are also very large, heavy, and complex organisms, they require monitoring and care to ensure survival and safety in the human landscape.