Lichens in Relation to Management Issues in the Sierra Nevada National Parks

McCune, Bruce; Grenon, Jill; Martin, Erin; Mutch, Linda

Lichens are a conspicuous part of ecosystems in the Sierra Nevada, a part that may provide valuable vital signs for evaluating the condition and trend in those ecosystems. Lichens are vulnerable to air pollution, especially acidifying sulfur and nitrogen compounds, fertilizing nitrogen compounds, and other anthropogenic disturbance. The central and southern Sierra Nevada are subjected to high levels of ozone, high and increasing nitrogen deposition, and unknown quantities of pesticides such as organophosphates from agricultural emissions in the Central Valley. Fire regimes have changed greatly over time, from relatively frequent fire historically, to fire exclusion, to its reintroduction as prescribed fire. Parts of the Sierra parks have been grazed by livestock, and some of this persists today. On top of these factors, climate is likely to change rapidly. Although a large literature exists on human impacts on lichens, almost nothing is known on this topic in the Sierra Nevada specifically. We are largely ignorant of the biodiversity, ecology, and ecological roles of lichens in the Sierra Nevada Park system (SIEN; henceforth “Sierra parks”, including Sequoia/Kings Canyon National Park (SEKI), Yosemite National Park (YOSE), and Devils Postpile National Monument (DEPO). The purpose of this project is, therefore, to synthesize existing data, written reports, and other information about lichens in and near the Sierra Nevada parks, as a first step toward developing better baseline data and assessing lichen populations or communities as potential indicators of ecosystem change.

Lichens in Relation to Management Issues in the Sierra Nevada National Parks

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