tag:blogger.com,1999:blog-5549306427964459740.post8549376186219700205..comments2023-12-23T05:14:34.273-05:00Comments on Wit's End: Lichens and Other MysteriesGail Zawackihttp://www.blogger.com/profile/01800944469843206253noreply@blogger.comBlogger3125tag:blogger.com,1999:blog-5549306427964459740.post-76787435450247394552009-10-20T15:21:52.521-04:002009-10-20T15:21:52.521-04:00This may be closer to home:
http://eco.confex.com/...This may be closer to home:<br />http://eco.confex.com/eco/2009/techprogram/P20713.HTM<br /><br />Friday, August 7, 2009<br />PS 95-189: Lichen distribution across a landscape gradient as an indicator of air pollution and habitat alteration<br />Bryan E. Dolney, Matthew R. Opdyke, and Laura Frost. Point Park University<br /><br />Background/Question/Methods<br /><br />Epiphytic lichen communities are well established indicators of urban air pollution and habitat alteration. In regions experiencing urban development, a long-term decline in species diversity of epiphytic lichen, particularly species sensitive to sulfur dioxide, nitrogen oxides, and particulate matter, may be linked to increasing transportation and industry. To investigate the application of epiphytic lichens as indicators of air pollution and habitat alteration in southwestern Pennsylvania, USA, we measured species diversity and lichen health along a landscape gradient, which included 12 plots within multiple urban sites in the City of Pittsburgh and 12 plots within two rural sites outside of downtown Pittsburgh’s airshed. Additionally, we transplanted lichens from rural sites to locations with contrasting air quality to evaluate differences in biomass growth rates across the landscape gradient. To further examine the impact of microhabitat on lichen health, bark pH was measured at all plots and compared to the health of epiphytic lichens. Tree bark provides the substrate for epiphytic lichen species, in addition to being a simple and sensitive indicator of air pollution.<br /><br />Results/Conclusions<br /><br />We found that urban and rural regions show contrasting communities of epiphytic lichen corresponding to air pollution and habitat alteration. More than twenty lichen species were identified among all sample plots, with the most common species being Flavoparmelia caperata and Parmelia squarrosa. Anaptychia palmulata and Parmelia squarrosa, two sensitive species to air pollution, were more robust and abundant at rural sites. Early results suggest that species richness of lichens can be used as an indicator of air quality. We also found that the distribution of lichens within any given wooded park is affected by habitat structure, such as canopy cover and moisture content. Lichens contribute to biodiversity, so that tracking changes in these communities can be an early indicator of more serious changes across the larger ecosystem.Hank Robertsnoreply@blogger.comtag:blogger.com,1999:blog-5549306427964459740.post-65629619992200476472009-10-20T12:13:27.926-04:002009-10-20T12:13:27.926-04:00Hank Roberts, this is the first message Dr. Rogers...Hank Roberts, this is the first message Dr. Rogers sent me:<br /><br />Dear Gail Zawacki, I have attached two research papers addressing lichen communities in aspen and aspen-associate tree species in our area. In terms of lichens, generally, there are species which proliferate in polluted environs and those that die-off. The "gray-green" species you are seeing in your area is likely (though I am not familiar with your proximity to urban pollution sources) one which has a high tollerance for nitrogen, sulfur, or related air borne substances (i.e., ammonia/ammonium). As you are probably already aware, lichens are very good indicators of air quality and this science has been around for at least 100 years (especially in Europe). A good source for finding more information on lichens as bioindicators is: http://fia.fs.fed.us/lichen/<br />I send him a link to this post already, since his name is in it.Gail Zawackihttps://www.blogger.com/profile/01800944469843206253noreply@blogger.comtag:blogger.com,1999:blog-5549306427964459740.post-57206191127612020832009-10-20T11:53:34.461-04:002009-10-20T11:53:34.461-04:00"... epiphytic lichens provide a clear indica..."... epiphytic lichens provide a clear indication of potential air quality impacts on total forest productivity."<br /><br />http://fia.fs.fed.us/library/fact-sheets/p3-factsheets/lichen.pdf<br /><br />Gail, you got that reference from<br /><br />> Dr. Paul Rogers of Utah State University<br /><br />Please follow up -- ask Dr. Rogers to look at what you concluded from reading the reference he sent you. <br /><br />I think you have read it wrong, and that lichens are sensitive to air pollution and die back fast in polluted air.<br /><br />Yes, lichen and fungi and much else will grow more thickly on dead wood. That's evidence of dead wood and clean air.<br /><br />But I'm just some guy on a blog.<br /><br />Please, ask Dr. Rogers to come read and comment on what you've posted after reading his suggestions.<br /><br />Please ask him to look at what you wrote above and tell you if you have understood how lichenHank Robertsnoreply@blogger.com