40 Nebraskaland • April 2020
Diversity
Approximately 5,600 lichen species are known from the
continental United States and Canada with roughly 1,110
of these occurring in the Great Plains. In North America,
lichen diversity is richest in the moist and shaded eastern
deciduous forests; the rugged and diverse Rocky Mountain
region; and the cold, northern forests and peatlands. Roughly
350 species are known from Nebraska. For comparison, 700
species have been documented for Wyoming and 500 species
for the forest-rich Missouri. Since the year 2000, however,
biologists have documented more than 100 new species
for our state. These collections were gathered mostly from
the western pine escarpments and the cool, moist, central
Niobrara Valley. Many more species are certainly awaiting
discovery.
Lichens are notoriously diffi cult to identify, often requiring
chemical tests and microscopic inspection to key them to the
species level. Unfortunately, very few biologists have lichen
expertise, which limits our ability to survey for them.
Ecology
Though small in stature, lichens play critical roles in
nature. In arid regions, such as the Great Basin, for instance,
soil crusts formed in part of lichens help stabilize soils,
and lichens containing nitrogen-fixing algae enhance
soil fertility. In alpine and boreal regions and areas of the
Plains, where lichens are abundant, they help conserve soil
moisture, reflect heat and weather and break down rocks,
the initial stage in soil development. In areas of Canada,
restorationists now establish lichens in recently burned
Elegant sunburst lichen graces a marble tombstone (date
of death 1911) in a prairie cemetery in southeastern South
Dakota.