1993 update, checklist of the vascular plants of Bryce Canyon National Park, Utah

An updated checklist of the vascular flora of Bryce Canyon National Park is presented, including 458 species arranged in 232 genera and 73 families. Four species have been added to the part list based on 1991 fieldwork: Arabis perennans , Arceuthobium divaricatum , Gentiana parryi , and Haplopappus acaulis . Recent changes in nomenclature have been included, and several species identifications have been corrected. The six largest families are, in decreasing size, Asteraceace, Pocaceae, Fabaceae, Brassicaceae, Scrophulariaceae, and Rosaceae. Common names and an index are provided.     

Additions to the vascular flora of Bryce Canyon National Park, Utah

Twenty-seven plant taxa previously unreported from Bryce Canyon National Park are listed.     

Annotated checklist of exotic vascular plants in Yellowstone National Park

Documentation of the arrival of exotic vascular plants in Yellowstone National Park has been sporadic. An annotated checklist of exotic vascular plants is presented, with information about the approximate arrival time in the park of each species and the current extent of the infestation. Yellowstones flora includes 187 exotic vascular plant species (14.8% of the flora), and the park has an extrapolated mean number of exotic species per 10 km 2 of 47.3. The situation in Yellowstone is compared with other areas in North America. The increase in exotics mirrors a corresponding increase in visitation.     

A checklist of the vascular plants of the House Range, Utah

A checklist of the vascular plants of the House Range, Juab and Millard counties, Utah, is presented. A flora of 373 species and infraspecific taxa in 231 genera and 60 families are reported. The geology, physiography, climate, and plant communities are briefly discussed. Several endemics occur in the study area and a new taxon has been described.     

Checklist of vascular plants for the Bighorn Canyon National Recreation Area

The checklist of vascular plants of Bighorn Canyon National Recreation Area is presented based on field collections and herbarium specimens. The checklist treats 656 taxa from 73 families.         

Pinyon-juniper woodlands in Zion National Park, Utah

Juniperus osteosperma-Pinus monophylla or P. edulis (P-J) woodlands are the most widespread plant community in Zion National Park (ZNP), southwestern Utah. These woodlands dominate nearly half of the park's land area. Our study of this vegetational complex is based on a sample consisting of 115 macroplots (each 0.01 ha in area) objectively distributed across the entire area of ZNP. We recognize 3 subtypes within the P-J complex: Juniperus osteosperma (Utah juniper) alone, juniper with P. monophylla (single-leaf pinyon), and juniper with P. edulis (two-leaf pinyon). The 2 pinyon pines rarely occur together, and thus the foregoing subtypes do not overlap geographically to a significant extent. The first 2 subtypes occur primarily below 1800 m elevation, while the latter is most commonly found above that elevation. Because of the scarcity of sizable expanses (over ～ 10 ha) of well-developed soils in ZNP, the P-J complex occurs primarily on sites where exposed bedrock covers a large portion of the habitat. As a result, over 90% of stands assigned to the P-J complex support less than 50% tree canopy cover (64% have less than 25% tree cover). Shrub cover increases along the woodland successional gradient. Pinyon cover increases faster than juniper cover. Microbiotic soil crust cover is consistently greater in J. osteosperma-P. monophylla woodlands than in J. osteosperma-P. edulis woodlands, but total living cover increases significantly along the successional gradient in both communities. To enhance plant and animal biodiversity, we recommend that pinyon-juniper woodlands of Zion National Park be managed so that late seral stages do not dominate large tracts.     

Holocene bison from Arches National Park, southeastern Utah

An artifact constructed from a bison ( Bison bison ) hornsheath was recovered from the surface of a sandstone shelter also containing skeletal remains of bison and bighorn ( Ovis Canadensis ). Radiocarbon dating of bison, bighorn, and the artifact indicate that all co-occurred on the central Colorado Plateau, southeastern Utah, either between A. D. 1405 and A. D. 1420, or between A. D. 1535 and A. D. 1605. Skeletal remains of the bison imply that the animal was of the local faunal community during the transition between Protohistoric and Historic time.     

Distributional study of the Zion Snail, Physa zionis, Zion National Park, Utah

The major hanging gardens and associated water seeps in Zion National Park were surveyed for the presence of the Zion Snail ( Physa zionis ). Environmental parameters, including water depth, water velocity, substrate slope, and algal cover, were measured to determine their effect on the local distribution of the snail. Large populations (densities 125 to 250/m 2 ) were found in the Virgin River Narrows area of the park and at a hanging garden and seep located 1.0 km north of Scout Lookout. Densities in other localities were low in comparison. Snails were not found in all hanging gardens or seeps. The major factor controlling within seep distribution was determined to be water velocity. Experiments were conducted to test the ability of the snail to remain attached during differing water flows. The snail showed an ability to remain attached during high flows, but few snails were found in areas of high flow.     

Habitat and plant distributions in hanging gardens of the Narrows, Zion National Park, Utah

Hanging gardens are insular plant communities of the Colorado Plateau. This study examines hanging gardens in the Narrows, Zion National Park, Utah. The floristic similarity of gardens and the presence of species in classes of variables which characterize the habitat are disclosed. Although the gardens are isolated and dissimilar, the individual species are not restricted in the range of habitat found. Floristic dissimilarity cannot be attributed to differences in habitat. These results are compared to studies of hanging gardens in eastern Utah.       

The bacterium Thioploca ingrica on wet walls in Zion National Park, Utah

Hanging gardens and wet wall habitats have been studied for the past several years in many arid regions of the Intermountain West. One unusual large wet wall habitat in Zion National Park was found to be covered with a mucilaginous red-colored growth of the filamentous gliding bacterium Thioploca ingrica Visloukh. This is the only habitat we have examined where the predominant matrix-forming organism was a bacterium rather than an alga.     

Endangered, threatened, extinct, endemic, and rare or restricted Utah vascular plants

The status of 382 vascular plant taxa with distribution in Utah is presented. Some 66 species are possibly endangered, 198 threatened, 7 extinct, and 20 extirpated within the state; 4 species have questionable taxonomic status. Included in the list are nearly 225 species of endemic plants, many of which are among the possibly endangered, threatened, and extinct or extirpated plants. Bibliographic citations, type locality, status, and distribution by counties is included for each species or infraspecific taxon. Two new species are described: Psoralea pariensis and Eriogonum natum. One new name, Astragalus barnebyi, is proposed; and one new variety, Eriogonum umbellatum var. deserticum, is proposed. The following new combinations are made: Cycladenia humilis var. jonesii; Aralia racemosa ssp. bicrenata; Heterotheca jonesii; Hymenoxys depressa; Xanthocephalum sarothrae var. pomariense; Thelypodium integrifolium var. complanatum; Thelypodium sagittatum var. ovalifolium; Arenaria kingii var. plateauensis; Psorothamnus thompsonae; Najas caespitosus; Oenothera gouldii; Eriogonum corymbosum var. revealianum; Penstemon humilis var. obtusifolius; Penstemon lentus var. albiflorus; and Viola purpurea var. charlestonensis.       

Fishtail Mesa: a vegetation resurvey of relict area in Grand Canyon National Park, Arizona

Relict sites are geographically isolated areas that are undisturbed by direct and indirect human influences. These sites facilitate long-term ecological monitoring by providing a reference for gauging impacts occurring elsewhere. Knowledge gained through comparing vegetation change on matched relict and proximal disturbed areas can help partition the causes of change into natural and human-produced components. Fishtail Mesa in Grand Canyon National Park is a 439-ha relict site that is inaccessible to domestic livestock. Human visitation is infrequent and irregular, and fires have never been suppressed or managed. In 1958, U.S. Forest Service range scientists conducted a survey of Fishtail Mesa to gather reference data on vegetation, wildlife, and soils. Vegetation sampling was conducted using a method called the ";";elb.";"; We returned to Fishtail Mesa in May 1996 to perform a general vegetation and floristic survey, assess the extent of vegetation change after 38 years, and evaluate the suitability of the site as a location for long-term surveillance of ecological change. Fishtail Mesas vegetation consists primarily of a Pinus edulis (pinyon) and Juniperus osteosperma (Utah juniper) woodland with an Artemisia tridentata (sagebrush) understory, or tree-type (310.9 ha), and an Artemisia and Poa fendleriana (mutton grass) steppe, or shrub-type (127.5 ha). Since 1958 vegetation changes in both shrub- and tree-types have been limited to only a few species. In the shrub-type we detected slight increases from 1958 to 1996 in both Pinus and Juniperus , and reexamination of 1958 photo sites confirmed that Pinus and Juniperus are reoccupying the shrub-type. Artemisia cover declined from 1958 to 1996, whereas Poa increased from near trace amounts in 1958 to moderate cover in 1996. In the tree-type, Poa has increased from 1958 to 1996, while Artemisia , Juniperus , and Pinus showed no apparent change. Other species such as Ephedra torreyana (Torrey joint-fir), Opuntia polyacantha (prickly pear), and Gutierrezia sarothrae (snakeweed) have decreased. Vegetation analysis aided by TWINSPAN revealed that the shrub-type is defined more on the basis of absence of Pinus and Juniperus rather than any special association of differential species with a high preference for this type. We interpret the ";";invasion";"; of the shrub-type by Pinus and Juniperus as a ";";reoccupation.";"; Indirect ordination using DECORANA inferred 2 environmental gradients, a moisture gradient and perhaps a substrate texture gradient, that appeared to influence vegetation distribution on Fishtail Mesa. Fishtail Mesa is a valuable relict area for studying the effects of livestock grazing and prescribed fire. It should be designated a Federal Research Natural Area based on its vegetation communities, size, and protection afforded by its location in Grand Canyon National Park.     

Trampling disturbance and recovery of cryptogamic soil crusts in Grand Canyon National Park

Cryptogamic soil crusts in Grand Canyon National Park were trampled by hikers, under controlled conditions, to determine how rapidly they were pulverized and how rapidly they recovered. Only 15 trampling passes were required to destroy the structure of the crusts; visual evidence of bacteria and cryptogam cover was reduced to near zero after 50 passes. Soil crusts redeveloped in just one to three years, and after five years the extensive bacteria and cryptogam cover left little visual evidence of disturbance. Surface irregularity remained low after five years, however, suggesting that recovery was incomplete.     

Flood frequency and the assemblage of dispersal types in hanging gardens of the Narrows, Zion National Park, Utah

Hanging gardens of the Narrows, Zion National Park, Utah, are plant communities growing at permanent seeps on the canyon walls. The gardens are isolated from each other and from other plant communities by vertical expanses of sandstone. Gardens consist mostly of herbaceous species less than 1 m tall. Though not individually species-rich, the hanging gardens are diverse as a group, and very dissimilar. This study considers two explanations of the heterogeneous distribution of species in hanging gardens. The assemblages of dispersal types in gardens of different spatial attributes and disturbance frequencies are examined. The G H statistic, a log likelihood ratio test, analyzes the incidence of dispersal types among classes of three spatial and two disturbance variables. The disturbance variables of expected flood frequency and soil depth segregate dispersal types; and the spatial variables of area, distance to possible seed sources, and relative isolation do not. Ferns and mosses, dispersing through spores, dominate a heterogeneous fugitive guild in the flood-prone gardens. Infrequently flooded gardens support more large-seeded species.     

Raptors of the Uinta National Forest, Utah

The past and present use of the Uinta National Forest by birds of prey was determined from historical records and surveys conducted during 1973, 1974, and 1975. Data describing the history, present status, and physical characteristics of each nest site were collected, along with the type and intensivity of human activity within a half - mile radius of the nest. In addition, limited data on fall migration of raptors along the Wasatch Front and the food habits of Golden Eagles are presented. Management guidelines, based on the results of this study, are proposed.     

Geography of exotic plants adjacent to campgrounds, Yellowstone National Park, USA

Eleven campgrounds in Yellowstone National Park were studied to determine the geography of 10 specific exotic plant species adjacent to campgrounds. Exotics were found in only 6 campgrounds. Six species were found at Mammoth campground, a low-elevation, dry site with year-round use. Only 2 species were found in the other 5 campgrounds. Exotics decreased with distance from Mammoth campground out to 6 m and then increased, suggesting a spread in their distribution. Significant associations were found between exotic presence and both open and closed canopies and low levels of disturbance. Generally, exotics decreased with an increase in cover of other vegetation forms. Five species were found most frequently in big sagebrush habitat types.     

Poisonous plants of Utah

Bird species density, diversity, and species richness in relation to habitat and seasonal variations were studied in the Betatakin Canyon area of Navajo National Monument, Arizona. The two most prominent habitat types are a riparian forest deep in the canyon bottom and a mature pinyon-juniper woodland on the mesas and slopes above the canyon. One hundred thirty-five species of birds were encountered during the study and recorded by season and habitat. The avifauna assemblages demonstrate definite habitat selection into groups associated with the riparian and pinyon-juniper woodland communities. Diversity, density, and species richness were greatest in the riparian habitat during the spring and summer months. The differences in bird community composition were greater between seasons than between habitats. Pinyon pine and Gambel oak were highly selected as perch sites in the pinyon-juniper and riparian areas, respectively.     

Habitat manipulation for reestablishment of Utah prairie dogs in Capitol Reef National Park

Utah prairie dogs were transplanted onto the site of a former colony, located in Capitol Reef National Park, Utah. Shrubs on the site were significantly taller than those found on active colonies in similar habitat located on the Awapa Plateau. Therefore, the transplant site afforded a test of the hypothesis that shrub height is a major inhibitory factor affecting occupation of sites by prairie dogs. Four sites of 5 ha each were used. Vegetation treatments — rotobeating, railing, and 2,4 - D herbicide — were carried out on three of the sites and the fourth was used as a control. Shrub height and percent cover were significantly reduced on all three treatment sites. Posttreatment effects on the vegetation showed that the greatest percent moisture of the herbage was found on the railed site, followed by the herbicide, rotobeaten, and control sites. Measurements of the visual obstructions to prairie dogs showed that the rotobeaten site had the greatest visibility, followed by the railed, herbicide, and control sites. Prior to release of prairie dogs on the study area, 200 artificial burrows per treatment were dug, using a power auger. In early summer, 1979, 200 Utah prairie dogs were live - trapped near Loa, Utah. An equal number by sex and age class were released on each treatment. In 1979 a significantly higher number of animals reestablished on the rotobeaten site. In 1980 and 1981 the rotobeaten and railed sites had significantly higher prairie dog numbers than the other sites. Reproduction occurred on both the rotobeaten and railed sites in 1980 and 1981. Results indicated that, when transplanting animals onto sites of former colonies presently overgrown with shrubs, the chances of a successful transplant could be increased by first reducing shrub height and density.     

Alpine vascular flora of the Tushar Mountains, Utah

The Tushar Mountains of southwestern Utah rise to a maximum elevation of 3709 m, with timberline and krummholz reaching maximum elevations of 3438 m and 3566 m, respectively. Voucher specimens were collected from the alpine region during eight field seasons to inventory this largely unknown alpine flora. Listed are 171 vascular plant species from 102 genera and 34 families that occur in eight types of plant communities within an alpine area of about 19.3 km 2 , the seven largest families are Asteraceae (29 species), Poacea (20), Brassicaceae (13), Rosaceae (12), Cyperaceae (11), Caryophyllaceae (10), and Fabaceae (8). Thirteen species are restricted to the alpine area. The perennial herb growth form accounts for 86.4% of the flora, 5.9% of the species are shrubs, and the remaining species are annuls to short-lived perennials. Bedrock at the alpine region is entirely of Tertiary igneous origin. Vegetation cover and species richness are highest on an andesite ash-flow tuff and latite flow and lowest on hydrothermally altered intercaldera rhyolites and tuffs. Forty-four species (26.0% of the indigenous flora) also occur in the Arctic, and 13 species are at a southern margin of distribution. Eight taxa (4.7% of the flora) are local or regional endemics. The majority of the alpine species appear to have migrated to the range by way of the contiguous mountain system to the north; statistical comparison with neighboring alpine floras shows the flora to be most similar to the floras of the Wasatch Mountains, Uinta Mountains, and Teton Range, with Sorensen's similarity indices of 52.8, 50.2, and 48.8% respectively.