Western diamondback rattlesnake in southern Nevada: a correction and comments

Reports of the occurrence of Crotalus atrox Baird & Girard from Nevada are reviewed. There is no evidence to support the occurrence of this species in Nevada.     

Vertical distribution of adult fish in Pyramid Lake, Nevada

Inshore and limnetic vertical distribution of adult fish in Pyramid Lake, Nevada was determined from late spring to early fall 1977. The benthic (23 m) inshore area exhibited a relatively diverse composition of five species, while the inshore surface and offshore limnetic zones were composed of over 98 percent tui chubs ( Gila bicolor ). Vertical fish distribution was associated with temperature and zooplankton distribution.     

Characterizing a first occurrence of bison deposits in southeastern Nevada

Late Holocene bison bones eroding from the badlands topography of Cathedral Gorge State Park in southeastern Nevada have been identified as the remains of Bison and date between approximately 400 and 850 years old. The bones were originally thought to be turn-of-the-century cattle and then early bison, so park personnel had need to solve this interpretive problem. A multidisciplinary team sought information on archaeology, geomorphology, paleontology, and paleoenvironment to document the 1st established occurrence of bison in this part of Nevada and to develop a hypothesis explaining their demise.     

Distribution of the moss family Grimmiaceae in Nevada

Twenty-six taxa of Grimmiaceae are listed from Nevada, all representing the genera Grimmia and Rhacomitrium. Rhacomitrium heterostichum (Hedw.) Brid. var. heterostichum and Grimmia atricha C. Muell & Kindb. ex Mac. & Kindb. are listed for the first time as occurring in Nevada. Within the state, the Mohave Desert the Great Basin desert, and the Sierra Nevada display unique composition of members of the Grimmiaceae. Grimmia anodon is the most widespread moss in the state. Others, such as Grimmia rivulare, G. conferta, and G. alpicola inhabit only the montane environments of northeastern Nevada.     

New Nevada entities and combinations in Eriogonum (Polygonaceae)

New species and varieties of the plant genus Eriogonum (Polygonaceae) that occur in Nevada are proposed. Eriogonum tiehmii and E. ochrocephalum var. alexanderae are endemic to Nevada, and E. lewisii is restricted to extreme northeastern Nevada and adjacent Utah. These entities belong to the subgenus Eucycla. Two varieties of E. umbellatum (of the subgenus Oligogonum) are proposed. The first, var. juniporinum , is found in eastern Nevada and in the desert ranges of southeastern California. The second is var. furcosum , which is restricted to the Sierra Nevada. One new combination is also proposed: E. nudum var. gramineum .         

The genus Eriogonum Michx. (Polygonaceae) and Michel Gandoger

New species and varieties of the plant genus Eriogonum (Polygonaceae) that occur in Nevada are proposed. Eriogonum tiehmii and E. ochrocephalum var. alexanderae are endemic to Nevada, and E. lewisii is restricted to extreme northeastern Nevada and adjacent Utah. These entities belong to the subgenus Eucycla. Two varieties of E. umbellatum (of the subgenus Oligogonum) are proposed. The first, var. juniporinum , is found in eastern Nevada and in the desert ranges of southeastern California. The second is var. furcosum , which is restricted to the Sierra Nevada. One new combination is also proposed: E. nudum var. gramineum .         

Records of stoneflies (Plecoptera) from Nevada

Distributional data are presented for 13 species of Nevada stoneflies including eight species new to the state list. A checklist of 30 species confirmed for Nevada is included.     

Montia linearis (Portulacaceae): a new record for Utah

Montia linearis Dougl., a plant known from British Columbia to Montana, Nevada, and California, is reported from Utah.     

An Erigeron from Nevada and a Penstemon from Idaho

Described as new species are Erigeron cavernensis Welsh & Atwood from the Schell Creek Range and Currant Mountain, White Pine County, Nevada, and Penstemon idahoensis Atwood     

Species composition, emergence, and habitat preferences of Trichoptera of the Sagehen Creek Basin, California, USA

An extensive study of larvae and adult Trichoptera of the Sagehen Creek basin. Sierra Nevada, California, USA, revealed 77 species representing 14 families and 41 genera. Twenty-six species were restricted to small water bodies (spring sources, seeps, spring streams, temporary ponds, and intermittent streams); 27 were restricted to Sagehen Creek, a second-order stream, and the mouths of two large spring streams. Similarity between species caught at black lights and those in emergence traps was 43%. There were two major peaks in adult emergence by species, midsummer and late summer-fall. A few species emerged during winter or throughout most of the year. The species composition of the community showed affinity with Oregon, the Great Basin, and the Rocky Mountains but very little similarity with the California Coast Range. Four of the most abundant species in the basin have very restricted distributions. Ecological separation of several groups of closely related species could be explained by major differences in larval habitats or by different emergence periods.     

Ecological impacts of Pogonomyrmex on woody vegetation of a Larrea-Ambrosia shrubland

Discovery of distinct mid-elevational bands of blackbrush ( Coleogyne ramosissima Torr.) shrublands on desert mountain slopes in the Mojave Desert caused an investigation of the relationships between environmental factors and Coleogyne distribution. Environmental factors were quantitatively examined to determine which were significant predictors of Coleogyne density at upper-elevational limits (ecotones) in the Spring Mountains of southern Nevada. Path analysis revealed significant, direct causal effects of air temperature, soil moisture, soil depth, and percent litter cover on the distribution of Coleogyne . Specifically, air temperature was a significant positive predictor, while soil moisture, soil depth, and percent litter cover were significant negative predictors of Coleogyne density, with the effects of other environmental variables parceled out. Path analysis also indicated that indirect effects of soil pH, bulk density, compaction, percent pore space, organic matter, soil temperature, salinity, cryptogam, and percent bare soil and rock cover on Coleogyne density were substantially more potent than their direct casual effects. Environmental attributes associated with elevational changes correlate with and may determine the density of Coleogyne shrubs at upper ecotones in southern Nevada.     

Additional records of the dark kangaroo mouse ( Microdipodops megacephalus nasutus ), with a new maximum altitude

Three specimens of Microdipodops megacephalus nasutus were captured in the Wassuk Mountains of western Mineral County, Nevada, which provide a second place of occurrence for the subspecies and a new altitudinal record of 2455 m for the genus. This is the first time this species has been found in the pinyon-juniper belt.     

Distribution and ecology of freshwater Ostracoda (Crustacea) collected from springs of Nevada, Idaho, and Oregon: a preliminary study

Fourteen freshwater ostracod species collected from 24 springs in Nevada, Idaho, and Oregon between 1991 and 1994 were classified. Their ecology, based on major water parameters (i.e., temperature, dissolved oxygen, pH, conductivity), and biogeographical distribution in North America were studied. Among these 14 species, 9 ( Ilyocypris bradyi , I. gibba , Darwinula stevensoni , Candona candida , Heterocypris incongruens , Herpetocypris reptans , H. chevreuxi , Prionocypris canadensis , P. longiforma ) are new records for Nevadas ostracod fauna, while 3 ( H. reptans , P. canadensis , and Cypria turneri ) are new species for Oregon. H. reptans , P. canadensis , and Heterocypris salina are also recorded as new for the ostracod literature of Idaho. Scottia pseudobrowniana , collected from Nevada, is a new ostracod species for the United States. The occurrence of 5 Holarctic species in the northern Great Basin area may suggest a possible historical relationship with the European ostracod fauna.     

Survival and development of Phoradendron californicum and Acacia greggii during a drought

Soil compaction from human trampling, biking, and off-road motor vehicle traffic was quantitatively investigated in a blackbrush ( Coleogyne ramosissima ) shrubland in Kyle Canyon of the Spring Mountains in southern Nevada. A significant difference was detected in soil compaction, bulk density, and percent pore space at a particular frequency of visits in each of 4 disturbance types. On average a single vehicle pass was equivalent to 10 human footprints. Ten and 100 footprints were equivalent to 1 motorcycle pass and 10 vehicle passes, respectively. Soil compaction is a product of increased bulk density and decreased pore space. The degree of soil compaction is a function of disturbance type and visit frequency when examining these 2 factors independently. However, interactive effects of disturbance type and visit frequency on soil bulk density, compaction, and percent pore space were not significantly different. The greatest effects occurred during the first few passes, with changes per pass decreasing as the number of passes increased in all 4 trails. Results of this study suggest that the effects of hiking and biking slowly increase over time relative to the effects of motor vehicle traffic in the Coleogyne shrubland of Kyle Canyon in southern Nevada.     

Hindia sphaeroidalis Duncan from the Devonian of Nevada (Porifera)

The small, spherical, lithistid sponge, Hindia sphaeroidalis Duncan, 1879, is reported from the Devonian and Silurian of the Great Basin for the first time. Devonian specimens came from the Emsian Bartine Member of the McColley Formation from near Roberts Creek, Roberts Mountains, and from the Eifelian part of the Nevada Group near Bishops Creek, north of Wells, Nevada. The Silurian occurrence, questioned because of poor preservation, is from the Laketown Dolomite, on Tunnel Spring Mountain in western Millard County, Utah.     

Bat distribution and hibernacula use in west central Nevada

We captured 299 individuals of 11 bat species in mist-nets at 18 water sources in west central Nevada from June through August 1994. Myotis ciliolubrum, Pipistrellus hesperus, M. californicus , and Corynorhinus townsendii were the most common species captured. These species are apparently broadly distributed throughout west central Nevada, occurring in a variety of habitat types. We captured Euderma maculatum at 2 localities. These represent the 1st known records of this species in Esmeralda County, Nevada. Mine adits were surveyed for hibernating bats from December 1994 through February 1995. We determined the presence of 3 hibernating species: C. townsendii, M. ciliolabrum and P. hesperus . Bats were present in 19 of 70 mines (27%) we surveyed at elevations ranging from 1500 m to 2460 m. C. townsendii was the most common species encountered. Our study provides some much-needed baseline data on bat distribution and use of mines for hibernacula in west central Nevada.     

Mountain ants of Nevada

The nest of the ant Formica propinqua W. M. Wheeler is reported from Washoe Co., Nevada.     

Stonefly (Plecoptera) records from the basin ranges of Nevada and Utah

Distributional records are given for 40 stonefly species on 15 isolated mountain ranges in Nevada and Utah.     

Haplopappus alpinus (Asteraceae): a new species from Nevada

The new species, Haplopappus alpinus of section Tonestus, is formally described and illustrated. It is endemic to the high mountains of central Nevada. Vegetative and floral morphology of related species is detailed. The new species appears to be most closely related to H. eximius but also demonstrates close affinity to H. aberrans (all three are diploids with n = 9).     

Additional records of Coleoptera collected at the Nevada Test Site, Mercury, Nevada

Thirty - nine species of Coleoptera not previously reported for the Nevada Test Site are listed.