2000 elemental analysis of lichens in Sleeping Bear Dunes National Lakeshore and George Washington Carver National Monument: Final report

Abstract

In the final report of the first study of the lichens and air quality in the Sleeping Bear Dunes National Lakeshore (SLBE) (Wetmore 1988) and George Washington Carver National Monument (GWCA) (Wetmore 1992) it was recommended that a restudy of the elemental analysis of lichens be done every five years. This report is on the results of a restudy done in 2000. In August; 2000, four species of lichens were collected at three of the same localities in SLBE as the previous studies. In GWCA only one species was resampled at one locality in May, 2000. The methods used were the same as in the previous studies. Statistical analyses of data from SLBE indicated that of the 15 elements measured in both years, six were significantly different for Cladina: Cd, Cr, Mn, Na, Pb and S. Chromium, Mn and Na all increased, while the other three decreased. The analysis of the GWCA data showed that twelve elements out of 23 plus ash changed significantly between 1991 and 2000, although this is based on very small sample sizes. The recommendation is made that the periodic restudy of elemental analyses of both areas be continued but on a more frequent interval in GWCA and with more samples to determine if the changes are consistent. The five-year periodic restudy in SLBE seems to be adequate.