Eight populations of Parmotrema species from the Shimek State Forest, Iowa (Croton and Lick Creek Units) were selected for study. Samples of Parmotrema perlatum, P. hypotropum, P. reticulatum, and P. austrosinense were collected and assessed for their concentrations of N, S, P, K, and Fe. We hypothesized that populations near the forest edge might have higher concentrations of these elements. There were no populations of this genus at the forest edge, and no significant differences in elemental concentrations between samples from the middle of the forest or near the forest edge. Two reasons are hypothesized to explain these results: forest age and forest density.