The pollen—Tree relationship within forests of Wisconsin and Upper Michigan, U.S.A.

Abstract

Pollen analysis of moss polsters collected from the floor of undisturbed Wisconsin and Upper Michigan forests provides information about pollen representation at the scale of the forest-stand. Linear relationships exist for several arboreal taxa when paired pollen percentages and tree-basal area percentages, which are measured from the surrounding 20 m, are displayed on scatter diagrams. Regression analysis using the geometric-mean solution quantifies these linear relationships. Betula is the most over-represented pollen type in the moss polsters, Pinus, Quercus and Tsuga are equitably-represented, and Acer is under-represented. Relatively large amounts of Betula, Pinus and Quercus pollen in moss polsters are recruited from further than 20 m. In Wisconsin lakes, by contrast, Pinus is the most over-represented pollen type and long distance transport of Betula pollen is relatively unimportant. In moss polsters, Betula pollen is the best represented type in northern Europe as well as in Wisconsin. Fagus is poorly represented in both continents.