Lichen Biomonitoring Program

In 1987, a lichen biomonitoring program was initiated in the Otter Creek and Dolly Sods Wildernesses of the Monongahela National Forest, West Virginia. This was a baseline study designed to accomplish the following objectives: (1) To characterize the lichen floras of the two wildernesses and note patterns characteristic of air pollution damage; (2) To establish permanent photographic study plots within which to record aspects of lichen community composition; (3) To establish permanent quadrats throughout the two wildernesses within which to collect samples of a single lichen species for elemental analysis.

Lichen communities were sampled in each wilderness and found to include numerous species known to be pollution-sensitive, indicating the lichen flora was not adversely affected by air pollution at that time. In addition, specimens of the lichen Flavoparmelia caperata were sampled within 121 1-km2 sections (80 in Otter Creek and 41 in Dolly Sods) and analyzed for sulfur and 23 other elements to provide baseline information about the air quality in the two wildernesses. Results of elemental analysis indicated sulfur and metal concentrations in test lichens were relatively low, although a significant positive correlation between sulfur concentration and elevation was noted.

In 1992, a reassessment of the air quality in the wildernesses was done using lichen floristic and elemental data. This follow-up study had objectives similar to the baseline
study: (1) To collect additional floristic information about the lichen communities representing the two wildernesses and to note patterns indicating air quality problems; ( 2} To re-photograph the permanent photo plots and note changes in lichen community structure; (3} To collect specimens of F. caperata for elemental analysis (sulfur, nitrogen and 23 other elements} so that comparisons could be made with data collected in 1987.

The resurvey yielded new floristic information for each wilderness. A total of 129 lichen species was identified from the collections made in the wildernesses; 101 were found in Otter Creek and 88 in Dolly Sods, but many were common to both wildernesses. These results represent nearly a doubling of the lichens identified in 1987, probably a consequence of a more extensive sampling effort, and include many species known to be pollution-sensitive. The present species-rich lichen flora indicates little (if any} adverse effect of pollution at the present time. 

The results of the lichen element analysis indicate changes in the ambient air quality since the 1987 baseline study was done. Seven elements (Na, Mn, Ti, Fe, Cu, Pb, Al} were found in significantly lower concentrations in 1992; three (Ba, Sr, S} were found in significantly higher concentrations. Concentrations of sulfur and nitrogen (components of acidic precipitation} were significantly higher in Dolly Sods than Otter Creek, probably a consequence of the higher elevations in Dolly Sods since significant positive correlations with elevation were obtained for each of these elements. The number of permanent sampling sites with lichen sulfur concentrations exceeding 0.20% dry wt. also doubled since 1987 (from 4 to 8). These elemental data indicate a reduction during the past five years in the impact of certain pollutants (metals); however, the increases in sulfur concentrations since 1987 and the elevational gradients observed for S and N indicate a potential air quality problem and the need to continue monitoring in the two wildernesses.

It is recommended that resurveys of the lichen communities of Otter Creek and Dolly Sods be done at five-year intervals to continue to monitor changes in the floras and the element status of test species. Such information, when combined with other monitoring data, will be valuable in documenting adverse effects on the air quality related values of the two wildernesses.

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