PARENT SESSION
Poster Session 2: Forest Ecology
Monday, August 8, 5:00 PM - 6:30 PM, Exhibit Hall 220 A-E, Level 2, Palais des congrès de Montréal

Application at two different scales of a lichen bioindicator.

Reis, Anne^*,1, Will-Wolf, Susan¹, Nelsen, Matthew¹, Trest, Marie¹, Makholm, Martha², Rolih, Kasey³, ¹ University of Wisconsin-Madison, Madison, WI² Wisconsin Department of Natural Resources, Madison, WI³ University of Massachusetts, Amherst, MA

ABSTRACT- Estimating effects of air pollution on lichen species and communities at different scales is crucial to interpreting their patterns of distribution, since many lichens are known to be sensitive to sulfur dioxide and other pollutants. Here, we compare pollution signals from tissue element concentration of Flavoparmelia caperata (L.) Hale from 26 locations in six Mid-Atlantic states (large scale: DE, MD, NJ, PA, VA and WV) and 43 locations in one Midwest state (small scale: south central WI). The Mid-Atlantic region encompasses over 33 million hectares and is geographically and topographically diverse, whereas the WI study area covers about 27 thousand hectares and is relatively similar in geography, with minor topographical variation. Lichen communities in both regions are affected by local (point-source), as well as regional pollution. Direct pollution measurement and regional pollution models convey information in a variety of units, such as kg/ha, g/L and tons/yr. and conversion between units is problematic. Therefore, our goal is to use lichens as biological translators to, first, distinguish the effects of different sources of pollution (local vs. regional) on lichens; and second, to interpret the combined effects of pollution on the biotic community regardless of the pollution source. Thalli of F. caperata from both regions were collected, cleaned, and analyzed for 19 elements using the same techniques and laboratory. In both regions, S and Cu were positively correlated with direct pollution variables. Lithium, a reliable dust signal, is for the Mid-Atlantic study independent of S and Cu (Pearson r = -0.04 to -.16), and is positively correlated with elevation, confirming that S and Cu are giving us signals for pollution independent of other factors (PCA ordination). Partial correlation analysis shows that local and regional pollution can, indeed, be distinguished in both regions and results of the element analysis can be used as a proxy to integrate the varying pollution data units. Thus, lichen tissue samples address both our goals for estimating contribution of air pollution effects to lichen community pattern.

Key words: lichens, forests, bioindicator, scale