Geology topics

C. M. Wetmore

Publications and source records attributed to C. M. Wetmore.

12 recordsLinked to original sources

USGS2010

Lichen diversity changes along the Mississippi River in the Minneapolis-St. Paul urban area

Lichen diversity along the Mississippi River in the Minneapolis-St. Paul urban area was studied in 2008 by sampling 37 localities along the 110-kilometer river basin, resulting in 76 species, which are thought to represent 80% of the complete flora. A significant decrease in lichen diversity toward the urban part of the river basin, as well as the presence of only one cyanolichen suggests that urban factors, e.g. air pollutants and habitat destruction may be affecting lichen diversity. In addition, lichen diversity has significantly decreased from that of 112 years ago, when a study by Fink reported 113 species, and a higher number of genera represented by a single species.

Minnesota↗

USGS2009

Changes in macrolichens of Douglas County, Wisconsin

Macrolichens collected in Douglas County, Wisconsin in the 1940s, 1970s and 2009 are compared in order to determine floristic changes. Species sensitive to disturbance, land use change, and possibly climate that have changed over these time spans are identified and suggested for further monitoring. The total lichen flora of Douglas County is compared with Harris’ 1977 publication of the lichens of the Straits of Mackinac.

Wisconsin↗

USGS2005

Lichens of the U.S. National Parks

Over 26,100 records of lichens present in 144 U.S. national park units were assembled from various sources into a database and analyzed. Within these 144 park units 2,435 species and 375 genera are reported, representing 63% and 74% of the North American flora, respectively. The park units are located in 41 states and Washington, D.C. The average number of species in a park is 104, but the median is 60, indicating there are many parks with a small number of species and a few with high numbers. Isle Royale National Park has the most species, 611, and twelve parks have only one species reported. The number of records of lichens present ranged from one for 25 parks, to 1,623 for Isle Royale. Physcia aipolia is the most frequently observed species, being found in 65 parks. One fourth of the park units are classified cultural resource parks, while the remainder are considered natural resource parks. This study was based on 453 sources, including literature citations, park reports and collections in the University of Minnesota Herbarium.

Bryologist↗

USGS2005

NPLichen: a database of lichens in the U.S. national parks

NPLichen, a database of lichens in the U. S. National Parks (Wetmore and Bennett, 1992), has been extensively revised and expanded, and is now available for public use at www.ies.wisc.edu/nplichen. As of this writing, the database contains 25,995 records of lichens in 144 national park units. The number of records of lichens not in the North American lichen checklist (Esslinger 1997) is 161, for a total of 26,156. These records include multiple occurrences of a species in some parks because more than one reference has reported presence of species. Consequently, the number of species in parks records (including new to North America) without these duplicate references is 14,986. Our table of misidentified taxa contains 307 records.

Evansia↗

USGS2004

Proposed list of extinct, rare, and/or endangered microlichens in Wisconsin

We propose that 41 species of macrolichens be listed for rare status in Wisconsin, along with 6 other species we think are now extinct in the state. Almost 60% of the species occur in the northern part of the state. Some of the extinct species occurred in the southern part. The rare and extinct species exist(ed) in 43% of the counties. None of the rare and extinct species are endemic to Wisconsin, and they represent 7% of the total lichen flora of the state. One species was last collected in 1884, but others were collected only recently. Forty-seven percent of the listed species are ranked critically imperiled (S1).

Wisconsin↗

USGS2003

Elemental chemistry of four lichen species from the Apostle Islands, Wisconsin, 1987, 1995 and 2001

Four lichen species sampled three times over a 15-year time span at four of the Apostle Islands, Wisconsin were analyzed for 16 chemical elements in order to determine time trends and spatial patterns. Factor analyses of the data revealed that elements associated with soils (Al, Cr, Fe, Na, Ni and S) have increased over the study period, while nutrient and pollutant elements (Cu, K, P, Pb and Zn) have decreased. Four other elements (Ca, Cd, Mg and Mn) were unchanged over time. Cladina rangiferina , a terricolous species, contained the lowest concentrations of all elements, while the corticolous species Evernia mesomorpha was highest in soil elements, Hypogymnia physodes was highest in Ca, Cd, Mg and Mn, and Parmelia sulcata was highest in the nutritional elements. Lichens on islands within 3–4 km of the mainland were highest in soil elements, which decreased with distance from the mainland. Elements that were 18–43% greater on the nearest islands were significantly different between near and far islands. Eight elements (Al, Ca, Cd, K, Mg, Mn, P and S) exceeded enrichment levels for Hypogymnia physodes , suggesting possible contamination problems for this species. Although Pb has decreased significantly over the time period, other elements have increased in the lichens while decreasing in the atmosphere, suggesting that accumulation in the environment is continuing.

Wisconsin↗

USGS2002

Patterns of lichen diversity in Yellowstone National Park

We here report 359 species in 103 genera from Yellowstone National Park. We found 71.3% of the total number of species in Picea engelmannii forests and 57.4% of the total number in Pseudotsuga menziesii stands. This compares to 42.3% of the species in Pinus contorta and 37.0% of the species in Pinus contorta/Pinus albicaulis stands. The presence of old Pseudotsuga menziesii and mature Picea engelmannii indicates that the forests have not burned for at least 300 yr, contributing to higher lichen diversity. The drier lodgepole pine and whitebark pine forests burn more frequently than every 300 yr and have fewer microhabitats for lichen growth. Species with thalli large enough to identify are beginning to recolonize substrates burned in the 1988 fires. Bryoria fremontii and Letharia vulpina exhibit levels of mercury and sulfur higher than those in other specimens in the region.

Idaho, Montana, Wyoming↗

USGS2000

16-year trends in elements of lichens at Theodore Roosevelt National Park, ND

An epiphytic lichen and a soil lichen in two very closely related genera (Parmelia sulcata and Xanthoparmelia chlorochroa, respectively) were sampled 16 years apart at Theodore Roosevelt National Park in North Dakota and measured for their elemental content. Mercury and cadmium decreased approximately 30% over the time period in both species. Sulfur decreased 8% in the epiphytic species, but increased 20% in the soil lichen. Factor analysis revealed that soil elements were higher in the soil lichen, indicating there was some soil contamination in that species. A relationship between iron and titanium was found only in the soil lichen. Sulfur and mercury were highly enriched in both species relative to the soil, which suggests that the atmosphere is a contributing source of these elements. New baseline values were calculated, 22 elements for both species, although it is not recommended that the soil lichen be sampled in the future.

North Dakota↗

USGS1999

Changes in element contents of four lichens over 11 years in the Boundary Waters Canoe Area Wilderness, northern Minnesota

Four species of lichen ( Cladina rangiferina, Evernia mesomorpha, Hypogymnia physodes, and Parmelia sulcata ) were sampled at six locations in the Boundary Waters Canoe Area Wilderness three times over a span of 11 years and analyzed for concentrations of 16 chemical elements to test the hypotheses that corticolous species would accumulate higher amounts of chemical elements than terricolous species, and that 11 years were sufficient to detect spatial patterns and temporal trends in element contents. Multivariate analyses of over 2770 data points revealed two principal components that accounted for 68% of the total variance in the data. These two components, the first highly loaded with Al, B, Cr, Fe, Ni and S, and the second loaded with Ca, Cd, Mg and Mn, were inversely related to each other over time and space. The first component was interpreted as consisting of an anthropogenic and a dust component, while the second, primarily a nutritional component. Cu, K, Na, P, Pb and Zn were not highly loaded on either component. Component 1 decreased significantly over the 11 years and from west to east, while component 2 increased. The corticolous species were more enriched in heavy metals than the terricolous species. All four elements in component 2 in H. physodes were above enrichment thresholds for this species. Species differences on the two components were greater than the effects of time and space, suggesting that biomonitoring with lichens is strongly species dependent. Some localities in the Boundary Waters Canoe Area Wilderness appear enriched in some anthropogenic elements for no obvious reasons.

Minnesota↗

USGS1999

Geothermal elements in lichens of Yellowstone National Park, USA

Geothermal features (e.g. geysers, fumaroles, vents, and springs) emit gaseous mercury, sulfur and heavy metals and therefore, are natural sources of these elements in the atmosphere. Field studies of heavy metals in lichens in Italy have detected elevated concentrations near geothermal power plants, and have determined that the origin of mercury is from soil degassing, not soil particles. We studied this phenomenon in a geothermal area without power plants to determine the natural levels of mercury and other elements. Two common and abundant species of epiphytic lichens, Bryoria fremontii and Letharia vulpina , were collected at six localities in Yellowstone National Park, USA in 1998 and analyzed for 22 chemical elements. Thirteen elements differed significantly between species. Some elements were significantly higher in the southern part of the park, while others were higher in the north. Levels of most elements were comparable with those in other national parks and wilderness areas in the region, except Hg, which was unusually high. The most likely sources of this element are the geothermal features, which are known emitters of Hg. Multivariate analyses revealed strong positive associations of Hg with S, and negative associations with soil elements, providing strong evidence that the Hg in the lichens is the result of soil degassing of elemental Hg rather than particulate Hg directly from soils. Average Hg levels in the lichens were 140 p.p.b. in Bryoria and 110 p.p.b. in Letharia , but maxima were 291 and 243 p.p.b., respectively. In spite of this, both species were healthy and abundant throughout the park.

Idaho, Montana, Wyoming↗

USGS1999

Covariance of lichen and vascular plant floras

The geographic relationships among taxonomic groups are important to study to determine patterns of biodiversity and whether or not associations occur between large groups, e.g., birds and vascular plants. This study was undertaken to determine relationships between higher plants and lower plants, specifically vascular plant and lichen floras in nine national parks of the Great Lakes region. No significant relationship was found between vascular plant floras and lichen floras in this area, which spans 1200 km longitudinally, or between an additional 19 areas from North America that were less than 1000 km(2) in area. For areas larger than 1000 km(2), however, a significant positive relationship existed for 33 areas that span one to approximately 150 million km(2). The ratio of numbers of vascular plants to lichens appeared to average just over 6 across the 33 areas. In the Great Lakes parks, between 28-30% of either the vascular plant or lichen species were singletons (occurring in only one park), but the parks that contained the most singletons were not congruent: Isle Royale had the most singleton lichens, while Indiana Dunes had the most vascular plant singletons. Fewer lichen species (2%) than vascular plants (4%) occurred in all nine parks. Latitude appeared to explain some of the variation between the two groups: vascular plants decreased with increasing latitude, while lichens increased.

Illinois, Indiana, Michigan, Minnesota, Ohio, Wisc↗

USGS1997

Chemical element concentrations in four lichens on a transect entering Voyageurs National Park

A three factor transect study was conducted to test the hypothesis that chemical elements from air emissions in the vicinity of International Falls, Minnesota could not be detected in lichens along a 24 km transect reaching into Voyageurs National Park. It was hypothesized that element concentrations in lichens would decline exponentially downwind and would reach background values at a distance before the park boundary. Four species ( Cladina rangiferina, Evernia mesomorpha, Hypogymnia physodes , and Parmelia sulcata ) were sampled at ten sites for 3 years and 17 chemical elements were measured. The most notable result was a curvilinear geographic trend for many elements, which decreased from International Falls and then increased towards the park. This trend was significant for many anthropogenic elements, including S, Hg, Cd, and Cr, and for all four species. This type of distribution pattern has been observed in Hypogymnia physodes in other studies downwind of a steel mill and an oil refinery. Cladina , a ground-dwelling lichen, generally had lower tissue concentrations of the elements than the three epiphytic species. Tissue concentrations over the 3 years of sampling declined an average of 12%. Sufficient evidence exists to conclude that lichen tissue element concentrations in the vicinity of International Falls may be related to local air emissions, and that an exponential decline of element concentrations downwind of the sources does not apply to this situation.

Minnesota↗