John L. Oliver


Indiana has experienced many climatic changes due primarily to its geographical location which brought it in contact with climates which find expression in boreal, grassland, and the southern deciduous forest vegetations. Many of the vegetational changes we will perhaps never be able to reconstruct for lack of fossil records. The more recent of these climatic changes, however, left their imprint on known records of forest history and on present-day plant distribution in Indiana. For the northern half of the state, pollen studies reconstruct remarkably well even the fluctuations of great formations and the climatic succession of formations and associations.