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13 recordsLinked to original sources
USGS2000

Ecology and conservation of a rare, old-growth-associated canopy lichen in a silvicultural landscape

Nephroma occultum Wetm. is a rare, epiphytic lichen associated with old-growth forests of northwestern North America. We describe its distribution, abundance, and habitat within the managed landscape of a southwestern Oregon watershed. Because this species is found mainly in the canopy, we used direct canopy access (tree climbing) in combination with ground (litter) searches for our surveys. We recommend this dual approach when confident determination of presence or absence of a canopy species is needed. Our surveys confirm that N. occultum is a rare old-growth associate within the area of this study, the southernmost extension of its known range. It was both rare across the landscape and uncommon in our primary study site, a 500 yr old stand. It was most often found growing close to the trunk on branches of large Pseudotsuga menziesii , but its distribution was sporadic even within an old-growth stand. The scarcity of very old stands, in combination with the limited ability of this species to disperse within and between stands, has likely contributed to its rarity within the watershed. Management for N. occultum should focus on populations and habitat needs rather than on individuals. Our calculations show that cutting with retention of individual trees surrounded by small buffers could result in the eventual loss of N. occultum from the study area.

Oregon↗
USGS2002

Lichens from Simeonof Wilderness, Shumagin Island, Southwestern Alaska

One hundred eighty-eight taxa of lichens are reported from Simeonof Island in the Shumagin Islands of southwestern Alaska. Wide-ranging arctic-alpine and boreal species dominate the lichens; a coastal element is moderately represented, while amphi-Beringian species form a minor element. The lichen component of Empetrum nigrum dwarf shrub heath, the dominant vegetation type, was analyzed to identify the most frequently occurring lichens within this community.

Alaska↗
USGS2003

Response of sphagnum fuscum to nitrogen deposition: A case study of mbrogenous peatlands in Alberta, Canada

Peatlands cover about 30% of northeastern Alberta and are ecosystems that are sensitive to nitrogen deposition. In polluted areas of the UK, high atmospheric N deposition (as a component of acid deposition) has been considered among the causes of Sphagnum decline in bogs (ombrogenous peatlands). In relatively unpolluted areas of western Canada and northern Sweden, short-term experimental studies have shown that Sphagnum responds quickly to nutrient loading, with uptake and retention of nitrogen and increased production. Here we examine the response of Sphagnum fuscum to enhanced nitrogen deposition generated during 34 years of oil sands mining through the determination of net primary production (NPP) and nitrogen concentrations in the upper peat column. We chose six continental bogs receiving differing atmospheric nitrogen loads (modeled using a CALPUFF 2D dispersion model). Sphagnum fuscum net primary production (NPP) at the high deposition site (Steepbank—mean of 600 g/m 2 ; median of 486 g/m 2 ) was over three times as high than at five other sites with lower N deposition. Additionally, production of S. fuscum may be influenced to some extent by distance of the moss surface from the water table. Across all sites, peat nitrogen concentrations are highest at the surface, decreasing in the top 3 cm with no significant change with increasing depth. We conclude that elevated N deposition at the Steepbank site has enhanced Sphagnum production. Increased N concentrations are evident only in the top 1-cm of the peat profile. Thus, 34 years after mine startup, increased N-deposition has increased net primary production of Sphagnum fuscum without causing elevated levels of nitrogen in the organic matter profile. A response to N-stress for Sphagnum fuscum is proposed at 14–34 kg ha −1 yr −1 . A review of N-deposition values reveals a critical N-deposition value of between 14.8 and 15.7 kg ha −1 yr −1 for NPP of Sphagnum species.

Alberta↗
USGS2004

Element content of Xanthoparmelia scabrosa growing on asphalt in urban and rural New Zealand

Xanthoparmelia scabrosa is a foliose lichen that grows abundantly on pedestrian and automobile asphalt in New Zealand, which are considered inhospitable habitats for lichens. Samples were collected at eight localities ranging from urban streets to very rural roads and analyzed for 28 chemical elements in order to determine elemental chemistry and to test hypotheses about tolerance mechanisms. Anthropogenic elements (Cu, Pb, and Zn) decreased significantly from urban to rural areas, while nutritional elements (K, P, and S) increased. Samples from urban areas contained 10% calcium. Sulfur was elevated at both urban and rural sites, possibly due to pollution in the former site and higher levels of sulfur-containing scabrosin esters at the rural sites. The ability of this lichen to accumulate high levels of Cu, Pb and Zn may make it useful as a remediation tool.

North Island↗
USGS2007

Biotic soil crusts in relation to topography, cheatgrass, and fire in the Columbia Basin, Washington

We studied lichen and bryophyte soil crust communities in a large public grazing allotment within a sagebrush steppe ecosystem in which the biotic soil crusts are largely intact. The allotment had been rested from grazing for 12 years, but experienced an extensive series of wildfires. In the 350, 4 x 0.5 m plots, stratified by topographic position, we found 60 species or species groups that can be distinguished in the field with a hand lens, averaging 11.5 species groups per plot. Lichen and bryophyte soil crust communities differed among topographic positions. Draws were the most disturbed, apparently from water erosion in a narrow channel and mass wasting from the steepened sides. Presumably because of this disturbance, draws had the lowest average species richness of all the topographic strata we examined. Biotic crust species richness and cover were inversely related to cover of the invasive annual, cheatgrass (Bromus tectorum), and positively related to cover of native bunchgrasses. Integrity of the biotic crust was more strongly related to cheatgrass than to fire. In general, we observed good recovery of crusts following fire, but only in those areas dominated by perennial bunchgrasses. We interpret the resilience of the biotic crust, in this case, to the low abundance of cheatgrass, low amounts of soil disturbance and high moss cover. These fires have not resulted in an explosion of the cheatgrass population, perhaps because of the historically low levels of livestock grazing.

Washington↗
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↗
USGS2025

DNA metabarcoding of biocrust lichen-forming fungi detects responses to disturbance and invasion

Biocrusts dominated by bryophytes and lichens perform important functions in dryland ecosystems but monitoring these communities can be cost prohibitive over broad scales. We explored DNA metabarcoding as a potential tool for monitoring biocrust lichen communities at a site in Washington (U.S.A.) that had already been surveyed for lichen diversity and community composition. We developed a DNA reference library using the internal transcribed spacer (ITS) region from specimens collected in the study area. We also visually estimated the abundance of lichen species or groups in 22 plots spanning a range of wildfire history and invasion by the exotic annual grass Bromus tectorum . At these plots, we collected bulk lichen community samples for metabarcoding using two approaches: small sample dishes and combined biocrust fragments collected using tweezers from all species observed. We used PacBio sequencing to simultaneously generate ITS barcode sequences for all lichen-forming fungi (LFF) present in the bulk samples, clustering similar sequences into operational taxonomic units (OTUs). Lichen communities detected visually and using DNA metabarcoding both captured a reduction of biocrust diversity and change in community composition related to the abundance of B. tectorum , suggesting that metabarcoding was able to identify the same dominant ecological pattern in biocrust lichens as visual sampling. The tweezer sampling approach captured on average 12.3 more OTUs than the dish approach and some taxa were more consistently detected by one approach or the other. After using the specimen DNA reference library to identify species associated with LFF OTUs, we determined that metabarcoding and visual sampling detected overlapping but different lichen species. Metabarcoding failed to detect common collected taxa, including: Arthonia glebosa, Candelariella spp ., Enchylium tenax, Lecanora muralis, Lecidella spp ., Leptochidium albociliatum, Massalongia carnosa, and Trapeliopsis glaucopholis. However, metabarcoding detected OTUs not visually observed in the genera Elixia, Lecanora, Lecanoropsis, Bacidina, Pyrenodesmia, Xanthocarpia, Trapelia, Verrucaria, and Verruculopsis . Furthermore, metabarcoding identified greater OTU diversity than expected within Diploschistes muscorum, Trapeliopsis bisorediata, and Trapeliopsis steppica . Our results suggest that metabarcoding alone or combined with visual methods could be a useful approach for monitoring biocrust lichen communities and their response to disturbance, invasion, and potential restoration.

Washington↗
USGS1983

Distribution of corticolous noncrustose lichens on trunks of Rocky Mountain junipers in Boulder County, Colorado.

Nineteen species of noncrustose lichens were found on Juniperus scopulorum bark; 3 species had relatively high cover and frequency values and were characterized as typical lichens of Rocky Mountain junipers: Xanthoria fallax, Phaeophyscia hirsuta and Physcia caesia. Total cover per tree was low (4%) and most species preferred the N and E sides of trunk bases. These distributional trends may reflect gradients of exposure to wind, insolation, and rate of bark exfoliation. -Author Juniperus scopulorum Phaeophyscia hirsuta Physcia caesia Xanthoria fallax.

Colorado↗
USGS1990

Effects of a coal-fired power plant on the rock lichen Rhizoplaca melanophthalma : chlorophyll degradation and electrolyte leakage

Chlorophyll degradation and electrolyte leakage were measured for the umbilicate desert lichen Rhizoplaca melanophthalma (Ram.) Leuck. & Poelt in the vicinity of a coal-fired power plant near Page, Arizona. Patterns of lichen damage indicated by chlorophyll degradation were similar to those indicated by electrolyte leakage. Regression analyses of chlorophyll degradation as well as electrolyte leakage on distance from the power plant were significant (p < 0.001), suggesting that lichen damage decreased with increasing distance from the power plant. Mean values for both variables at the two sites closest to the power plant (7 and 12 km) differed significantly from values for the two sites farthest from the plant (21 and 42 km; p < 0.001). Mean values within each group (7 and 12 km; 21 and 42 km) do not differ significantly for either parameter. It is suggested that effluents from the power plant combine with local weather factors to produce the observed levels of damage.

The Bryologist↗
USGS1998

Forest floor bryophytes of Pseudotsuga menziesii-Tsuga heterophylla stand in Oregon: Influences of substrate and overstory

Species richness and abundance of bryophytes inhabiting forest floor substrates were assessed at two sites in western Oregon. Bryophyte diversity, abundance, and community composition were compared between sites, and between young forest stands (~55 yrs) and old-growth stands (400 + yrs) within each site. Relationships of stand structural features to diversity and community composition were assessed by stratifying sampling between "diversity" plots placed in areas of greater structural diversity, such as hardwood openings and remnant old-growth trees, and "matrix" plots situated within the remaining more homogeneous conifer-dominated forest matrix. Richness, particularly for liverworts, was significantly higher in old-growth than young stands, and the two ages differed significantly in community composition. Substrate (ground versus coarse woody debris) and overstory (conifers versus hardwoods) were most strongly correlated with variation in community composition. Relatively open hardwood-dominated diversity plots differed in composition from matrix plots. Bryophyte abundance was lower in denser stands and plots, and positively correlated with canopy gaps, percentage of hardwoods, and incident solar radiation. These results suggest that availability of light may limit bryophyte productivity in these stands.

Bryologist↗
USGS2002

Algal layer ratios as indicators of air pollutant effects in Permelia sulcata

Parmelia sulcata Taylor is generally believed to be fairly pollution tolerant, and consequently it is sometimes collected in urban and/or polluted localities. The condition of these specimens, however, is not always luxuriant and healthy. This study tested the hypothesis that total thallus and algal layer thickness, and the algal layer ratio would be thinner in polluted areas, thus allowing these characters to be used a indicators of air pollutant effects. Herbarium specimens were studied from 16 different localities varying in pollution level. The thallus and algal layers and ratio were not affected by year or locality of sampling, but decreased 11, 31 and 21% respectively between low and high pollution level localities. These results agreed with earlier studies using other species, but further work is needed to clarify the effects of geography and substrate on these phenomena.

Delaware, Indiana, Iowa, Massachusetts, Michigan, ↗