Cindy Johnson-Groh wrote an article in 1985, "Vegetation Communities of Ledges State Park, Boone County, Iowa," which was published in The Proceedings of the Iowa Academy of Science, 92(4):129-136. For Lab Report 1, question 2, use this table, reproduced from Johnson-Groh's article (Celtis occidentalis was mistakenly omitted in Johnson-Groh's original table and has been added to this table) as a reference.
Most of the overstory species have trees occurring in two or all three of the
areas we sampled. However, each of these species is clearly more abundant in
one of the areas than it is in the other two. Thus, if we define communities
according to the most abundant or most dominant overstory species, these species
are very useful in defining community types.
We can also see that some species occur in some communities only as seedlings
or immature trees that are less important in defining communities than are mature
Other characters such as average size and unique species can be useful in describing additional aspects of the different communities, but would not form a very good basis for defining forest communities.