NCRS - The Changing Midwest Assessment

Since the 1930s, the Forest Inventory and Analysis research unit of the North Central Research Station has monitored the volume of trees on public and private timberland. We are interested in the volume of growing-stock trees because they provide the raw materials for the wood products that we use every day.

Growing-stock trees are defined as live timberland trees of commercial species that contain at least one 12-foot saw log or two noncontiguous saw logs 8 feet or longer - excluding rough and rotten trees. A saw log is a log that is 8 feet long, at least 9 inches diameter at breast height, and free of defects that would prevent its use as a wood product.

This slide show consists of a series of maps that depict how the volume (cubic feet) of growing-stock trees on all public and private timberland changed from approximately 1980 to 2000. Data were retrieved from the Forest Inventory and Analysis Data base.