Ralph Sheldon Hosmer was Hawaii's first territorial forester, a contemporary of Gifford Pinchot who was among the group of educated American foresters that organized what is now the United States Forest Service. Hosmer later joined the faculty of Cornell University as head of the department of Forestry, where he served for 28 years until his retirement.

A forester is a person who practises forestry, the science, art, and profession of managing forests. Foresters engage in a broad range of activities including ecological restoration and management of protected areas. Foresters manage forests to provide a variety of objectives including direct extraction of raw material, outdoor recreation, conservation, hunting and aesthetics. Emerging management practices include managing forestlands for biodiversity, carbon sequestration and air quality.