Lichen flora of the Great Plains

Lichenized fungi (or lichens) are fungus species with a photosynthethic organism (a green alga or cyanobacterium) incorporated into their thallus. The photosynthetic partner in this symbiosis allows the lichen to make its own carbohydrates, like a green plant. Though not particularly diverse, lichens are cosmopolitan and ecologically important. Some species colonize primary habitats and help to make them suitable for plants. Other species stabilize erodable soils or fix nitrogen into the soil. Still others serve as food sources or even building materials for animals. Some species are sensitive to air pollution and have been used in air quality studies. The Lichen Flora of the Great Plains project is being carried out under the auspices of the R.L. McGregor Herbarium, the botanical research division of the NHMBRC. Our research is aimed at understanding the diversity, distribution, and status of lichenized fungi in the central part of North America, a region that has historically been neglected by lichenologists.

Lichens are tolerant of desiccation and other kinds of environmental stresses. Many species flourish in the hottest, driest places in the world. In the Great Plains, we find species in our most inhospitable habitats, but many lichens will only grow on a particular substrate. In our region, species may grow on bark and twigs of woody plants, on decorticated wood, on calcareous or non-calcareous rocks, on soil or humus, or as parasites on other lichens, non-lichenized fungi, or bryophytes. One of the objectives of our work lies in finding study sites with a diversity of substrates. Generally speaking, the greater the diversity of substrates, the greater the lichen diversity. In some parts of the region, this no easy task.

Although still in its early stages, the project has already afforded us a basic understanding of the lichen diversity of the region and is yielding other promising results. Included among our recent collections are species new to science, new to North America, or new to the Great Plains and adjacent regions.