Macrolichen diversity in Noatak National Preserve, Alaska

Abstract

We sampled macrolichens in Noatak National Preserve to help address the need to document lichen biodiversity in Arctic ecosystems and to initiate regional-scale monitoring in the face of climate change and air pollution. We used a stratified random sample to allow unbiased park-wide diversity estimates, along with an intensive sample in a limited area. The purpose of the intensive sample was to allow us to calculate a correction from diversity estimates based on a single person in a time-constrained method to a value that more closely approximates the “true” diversity of a plot. Our 88, 0.38-ha plots averaged 26 species of macrolichens in the sample, while our best estimate of the true average was 42 species per plot. Our raw estimate of gamma diversity (park-wide macrolichen species richness) was 209 species, with jackknife estimates adjusting this to 255 or 290 species, depending on the estimator. Overall beta diversity was rather high at 7.1, reflecting the considerable variation in lichen communities among topographic positions, rock chemistry, substrate pH, climate, and vegetation. The richest lichen communities were in conifer forests, low birch/ericaceous vegetation, dwarf shrub, and talus lichen cover. Sparse vegetation was the cover type with lowest lichen species richness, reflecting the frequency of bare rock in that cover type. The herbaceous cover type was the most heterogeneous in lichen communities, having a high gamma diversity, high beta diversity, but averaging rather low alpha diversity. Several notable species are among the 364 taxa reported here. Leucocarpia biatorella is reported as new to the American Arctic. Cladonia libifera and C. jacutica are newly reported for North America. A second location for Rhizocarpon cumulatum beyond the type locality was found. The range of Parmelia squarrosa is extended ca. 1500 km north of coastal southeast Alaska. The high landscape-level diversity and high beta diversity in Noatak National Preserve provide a rich biotic tapestry for detecting future changes in macrolichen communities.