The International Society of Arboriculture (ISA) is the largest and most influential arboricultural organization in the world and has served the tree care industry for over eighty years as a scientific and educational organization. ISA was founded in 1924 when a group of forty individuals, each engaged in a phase of tree work or research, were called together by the Connecticut Tree Protection Examining Board to discuss shade tree problems and their possible solutions. It was during this meeting that the group identified a need for gathering tree care information and for providing a means for its dissemination. The National Shade Tree Conference (NSTC) was founded soon thereafter.
NSTC experienced gradual growth until 1929, when the economy in the United States collapsed and membership in the young organization sank to fourteen and continued to look bleak for several years, but in 1936, membership grew from thirty-three the previous year to one hundred forty-seven. With few exceptions, steady growth has been seen every year since.
Due to its influence and membership spreading beyond the borders of the United States, the organization changed its name to the International Shade Tree Conference (ISTC) in 1968. Only a few years later, in 1976, in order to more accurately reflect its broadening scope, the name was again changed, this time to the International Society of Arboriculture.
ISA continues to be a dynamic medium through which arborists around the world share their experience and knowledge for the benefit of society. ISA, aligned on many fronts with other green organizations, is working hard to foster a better understanding of trees and tree care through research and the education of professionals as well as global efforts to inform tree care consumers.
Click here to learn more about ISA.