Preface: nearly a decade ago I was asked to contribute to a book about species of concern in the Colorado Plateau ecoregion focusing on all taxa. I drafted up a section about mosses and lichens, focusing on gypsiferous species of biocrusts, which is a rare habitat. There are no federally listed mosses or lichens, not because they don't exist, but rather because the Endangered Species Act categorically excludes them.
I asked Roger Rosentreter (lichenologist), and Lloyd Stark (bryologist) for tips on other non-gypsiferous species I ought to mention.
Having heard nothing about the book in many years, I think I can assume the project is dead. In the meantime, I reckon its more useful here than on an old hard drive in an obsolete file format. I've supplemented it with links to images from the web, if they exist.
Regarding status, vulnerable means that it could conceivably be extirpated. For example rarity of habitat would render something vulnerable. At risk refers to a vulnerable species that is threatened by a stressor.
MOSSES AND LICHENS OF GYPSIFEROUS SOILS
NODULE CRACKED LICHEN
Status in region: At risk
Status elsewhere: At risk in the Americas
DESCRIPTION ~ Nodule cracked lichen was first
encountered in the Americas in the mid-1980's, and has been found to be locally
common species confined to the gypsiferous soils of the Colorado Plateau.
Although it is has a widespread distribution around the world, its preference
for a very rare habitat type in North America makes it a species of concern.
This lichen is composed of many scales of ~3-5 mm diameter with lobed margins.
Generally the appearance of the lichen is white due to a covering of oxalate
salts, but the thallus underneath is actually pale brown. It has black fruiting
bodies immersed in the thallus that lack any kind of rim around them. Colonies
are irregularly shaped and generally less than 5 cm in diameter.
Vulnerability Factors: Habitat specialist,
restricted range
NEVADA GYPSUM MOSS
Status in Region: At risk
Status in other regions: At risk
DESCRIPTION~ This rare moss was recently
described in 1995 as a result of morphologically well-developed collections
made during California bearpoppy studies. Nevada gypsum moss appears to be a
widely but sparsely distributed species of western North America,
almost exclusively on gypsiferous soils. It is distinguished by other mosses of
the same habitat by its lack of an awn (hair-like projection) on its leaf tips,
and its dark green to black leaves that tend to spiral around the stem near the
top. Its small stature (usually < 2mm tall) makes a handlens a must to
observe these features. Many desert mosses have skewed sex ratios, but to date
a male individual of this species has yet to be found making it one of the
champions.
Vulnerability Factors: Habitat specialist,
restricted range, possible low genetic diversity due to lack of sexual
reproduction
DESERT CRATER LICHEN
Status in region: Vulnerable {EDITORIAL NOTE: THIS SPECIES IS QUITE ABUNDANT, EVEN DOMINANT IN A RARE HABITAT TYPE}
Status elsewhere: Widespread and stable
DESCRIPTION ~ Desert crater lichen is found on
several continents but on the Colorado Plateau it is strongly
restricted to the rare gypsiferous soils where large white populations can be
visually impressive. This lichen forms rather large colonies often exceeding
5cm in diameter and is pure white. It tends to have a rugose, undulating
surface and has large (~ 2mm) black fruiting bodies which are bowl shaped and
sunken into the thallus surface like a crater. This species tends to have a
very clumped distribution, so if you find some you are likely to find a lot.
Vulnerability factors: habitat specialist,
restricted range
LARGELEAF GYPSUM LICHEN
Status in region: At risk
Status elsewhere: At risk globally
DESCRIPTION ~ Largeleaf gypsum lichen has been
confusing lichenologists since the 1920's, and was not discovered in the US
until 1990. Its unique fruiting body which grades into the vegetative thallus
afforded it a designation as a new genus solely representing a new family,
Gypsoplacaceae. It is a squamulose lichen with olive - tan squamules (scale-like
mini thalli) usually about 0.5 - 1 cm in diameter. The fruiting bodies, when
present, look like upraised brick red swellings on the squamules and may be
irregular to dome shaped. Although fairly large in the soil lichen world,
colonies are usually less than 5cm in diameter. This species is a rare one even within its specialized habitat which is also rare.
Vulnerability Factors: Low population density,
habitat specialist, restricted range.
GYPSUM-LOVING RIM LICHEN
Status in region: At risk
Status elsewhere: At risk globally
DESCRIPTION ~ This lichen was unknown to
science until collected in the San Rafael Swell in 1998, and has since been
observed at scattered locations around the Colorado Plateau. Gypsum-loving rim
lichen is chalky white to ashy gray and forms a tightly adhering crust on the
soil surface. Its thallus (vegetative portion) is divided into small partitions
called areoles. It bears black disk shaped fruiting bodies (1-2 mm dia.) with a
white margin that are flush with or sitting slightly atop the thallus. A
typical specimen is about 3 - 5 cm in diameter and irregularly shaped.
Vulnerability Factors: Habitat specialist,
restricted range.
Habitat: These species are strongly restricted
to arid and semi-arid sites with gypsiferous soils such as those derived from
gypsum-bearing portions of the Carmel
Formation, the Paradox Formation, and the Moenkopi Formation (most of
which occur at 5000 - 6500 ft). Such sites are found across southern Utah and
in southwestern Colorado. They occur as components of the conspicuously well
developed biological soil crusts generally found on these soils.
Threats and Concerns: On the Colorado Plateau,
these species are endemic to an inherently rare habitat type, and are uncommon
to rare within that habitat type even when undisturbed. Largeleaf gypsum lichen
is a rare species even within this special habitat type. Most of the gypsum
soils of the plateau are degraded to some extent by livestock activity and off
road vehicle use, and truly undisturbed examples may be lacking. As population
growth continues in the region, economical exploitation of the more pure gypsum
deposits may occur to satisfy demand for products such as drywall. Gypsum areas are particularly popular with users of dirt bikes and all-terrain vehicles.
Conservation: When planning road and trail
construction, gypsum areas should be avoided whenever possible. Enforcement of
off-road vehicle regulations should be prioritized in these areas. Plant cover
is poor on gypsum soils, therefore they offer relatively little forage value to
livestock. Grazing of these fragile habitats could and should be phased out
without creating major economic impacts. Because gypsiferous soils generally
occur in relatively small patches, a network of small fenced reserves could
potentially maintain the endemic biota.
Notes: Because several soil crust species and
some vascular plant species are rare gypsum endemics, and gypsum soils cover
very little area, it is practical and possible to conserve them all by
conserving the habitat in small reserves. We thank Dr. Larry St. Clair of BYU
for sharing his expertise on gypsiferous lichens, and Dr. Lloyd Stark of UNLV
for information pertaining to Didymodon nevadensis.
OTHER MOSSES AND LICHENS OF CONCERN
LITTLE FRINGE MOSS
Crossidium seriatum
Status in region: Unknown
Status elsewhere: At risk globally
DESCRIPTION ~ This little fringe moss is an
extremely rare western North American soil moss with a primarily hot desert
distribution. It has never been collected in the Colorado Plateau but likely
occurs in the more xeric portions, albeit very rarely. Although this species
cannot be separated from lookalikes in the field, perhaps its best identifying
characteristic is its extremely small size. A typical field specimen is
frequently less than 0.5 mm tall and although it does generally have a white
hairlike point on its leaf tips, it never appears as a white hairy cushion.
With the naked eye, individuals look like little black dots.
Vulnerability Factors: Low population density,
restricted range
Habitat: This moss occurs on sandy or
gypsiferous soils of aridlands. Dr. Lloyd Stark suggests that this species is
primarily centered around the gypsiferous soils near Lake Mead, thus its most
likely habitat on the Colorado Plateau includes the more xeric gypsiferous
substrates at the margins of the Colorado Plateau ecoregion such as those near St. George, Utah. Other possible localities include exposures of the Paradox formation in
Cataract Canyon and adjacent side canyons.
Threats and concerns: Soil disturbances of
various sorts are the most likely stressors: foot traffic, livestock grazing,
and off road vehicles.
Conservation: Initially, the best strategy is
simply to determine that the species does indeed occur on the Colorado Plateau
so that the habitat characteristics can be better defined and stressors better
identified. As a preemptive strategy, gypsiferous habit reserves should be
developed as described previously. Fortunately, the most likely localities for
this species happen to be in protected areas (Canyonlands National Park, and
Glen Canyon National Recreation Area), but they could potentially be impacted
by river users.
Entosthodon planoconvexus
Status in region: Vulnerable
Status elsewhere: Globally vulnerable
DESCRIPTION ~ This exceedingly rare moss is
known on the Colorado Plateau from only one location in Canyonlands (deposited by the author at the National Park Service Southeast Utah Group's herbarium in Moab, Utah), and is
known from only four other collections worldwide. Entosthodon planoconvexus
is a short moss with rather large yellowish green leaves that are spreading
when moist and shriveled when dry. Its sporophyte, when present, consists of an
upside-down pear-shaped capsule borne on a reddish stalk.
Vulnerability factors: Low population density
Habitat: Because of its rarity, the habitat of
this species is poorly defined although it tends to occur on dry soil at the
base of rocks. The Canyonlands specimen grew in a dry sandy soil layer over
rock and adjacent to a rock outcrop. It is an occasional associate of
liverworts of the genus Targionia.
Threats and Concerns: The main concerns with Entosthodon
planoconvexus are its naturally highly isolated small populations. Because
it tends to grow in at least partially protected habitats, the population is
likely stable, however stochastic events or disturbance could easily drive this
species locally extinct. Livestock and recreation impacts are the most likely
anthropogenic stressors of this species.
Conservation: It is difficult to recommend conservation
strategies for this species without knowing what potential stressors are.
Perhaps the best strategy is simply to determine where the species occurs so
that the habitat characteristics can be better defined and stressors
identified. Currently, bryophytes are not generally included in inventory and
monitoring projects.
Notes: Dr. Lloyd Stark of UNLV provided
helpful information on this species.
MINNESOTA ROCK LICORICE
Lichinella minnesotensis
Status in Region: Unknown
Status elsewhere: Possibly vulnerable in western North
America
DESCRIPTION~ This rock licorice lichen is apparently
a North American endemic with a primarily eastern distribution. There are some
rather disjunct collections from the midwest and west including a single
collection from near Kanab, Utah. This black lichen is composed of clumps of
ascending convoluted lobes. It is jelly like and semi-transparent when wet.
Colonies are generally only about 1 cm in diameter.
Vulnerability Factors: Isolated populations
Habitat: Minnesota rock licorice is found in
shallow fissures or crevices on rock outcrops. The sole Colorado Plateau
collection was from a limestone substrate of the Timpoweap member of the
Moenkopi formation in Grand Staircase-Escalante National Monument. It is difficult to characterize the habitat
characteristics of this species on the Colorado Plateau because only one
collection has been made.
Threats and Concerns: It is unknown whether
this species is threatened by anthropogenic forces, buts its rarity in the
region suggest it is vulnerable. Fortunately, its habitat type affords
considerable protection.
Conservation: It is difficult to recommend
conservation strategies for this species without knowing what potential
stressors are. Perhaps the best strategy is simply to determine where the
species occurs so that the habitat characteristics can be better defined and
stressors identified if they exist. Currently, lichens are not generally
included in inventory and monitoring projects.
Notes: Dr. Roger Rosentreter of the BLM
provided information on his Kanab-area collection of this species.
HAIRY MOUTH MOSS
Trichostonum sweetii
Status in region: Vulnerable
Status elsewhere: Globally vulnerable
DESCRIPTION ~ Hairy mouth moss is known from
only three collections on the Colorado Plateau (one a dubious identification)
and only a handful more from western North America where it is endemic. This is
a fairly large moss for arid regions (up to 2cm tall) and is an inhabitant of
shady crevices. It has large, narrow, bright green leaves (2-3 mm long) which
are spreading and widest just below the apex.
They may occur as small tufts or scattered individuals mixed with other
species.