Skip to main content
Advanced Search

Filters: Tags: artemisia tridentata (X)

65 results (116ms)   

Filters
Date Range
Extensions
Types
Contacts
Categories
Tag Types
Tag Schemes
View Results as: JSON ATOM CSV
thumbnail
Sage-grouse (Centrocercus spp.) were abundant in all of Utah's 29 counties at the time of European settlement wherever sagebrush (Artemisia spp.) occurred. Greater Sage-Grouse (G. urophasianus) inhabited areas north and west of the Colorado River, and Gunnison Sage-Grouse (G. minimus) occupied suitable habitat south and east of the Colorado River. The largest Greater Sage-Grouse populations in Utah are currently restricted to suitable habitats in Box Elder, Garfield, Rich, Uintah, and Wayne Counties. A remnant breeding population of Gunnison Sage-Grouse occurs in eastern San Juan County. We stratified Greater Sage-Grouse populations (1971-2000) by counties where the 1996 to 2000 moving average for estimated spring...
thumbnail
Historical disturbance regimes are often considered a critical element in maintaining native plant communities. However, the response of plant communities to disturbance may be fundamentally altered as a consequence of invasive plants, climate change, or prior disturbances. The appropriateness of historical disturbance patterns under modern conditions and the interactions among disturbances are issues that ecologists must address to protect and restore native plant communities. We evaluated the response of Artemisia tridentata ssp. wyomingensis (Beetle & A. Young) S.L. Welsh plant communities to their historical disturbance regime compared to other disturbance regimes. The historical disturbance regime of these...
Pathogens and herbivores can severely reduce host fitness, potentially leading to altered succession rates and changes in plant community composition. Thus, to predict vegetation dynamics under climate change, it is necessary to understand how plant pathogens and herbivores will respond. Pathogens and herbivores are predicted to increase under climate warming because the amount of time available for growth and reproduction will increase. To test this prediction, we used a warming experiment in which heaters were suspended over a natural montane meadow for 12 years. In the summer of 2002, we quantified damage by all the observable (aboveground) pathogens and herbivores on six of the most common plant species (Artemisia...
Turgor maintenance, solute content and recovery from water stress were examined in the drought-tolerant shrub Artemisia tridentata. Predawn water potentials of shrubs receiving supplemental water remained above ?2 MPa throughout summer, while predawn water potentials of untreated shrubs decreased to ?5 MPa. Osmotic potentials decreased in conjunction with water potentials maintaining turgor pressures above 0 MPa. The decreases in osmotic potentials were not the result of osmotic adjustment (i.e. solute accumulation). Leaf solute contents decreased during drought, but leaf water volumes decreased more than 75% from spring to summer, thereby passively concentrating solutes within the leaves. The maintenance of positive...
We conducted a field experiment to assess interrelationships between leaf-tissue secondary chemistry, avian predation, and the abundance and diversity of arthropods occurring on sagebrush (Artemisia tridentata) in central Oregon. Arthropods were removed from individual shrubs, some of which were then caged to exclude birds. Secondary chemistry and arthropods were sampled at intervals up to 56 wk following the defaunation/caging treatment. Recovery rates differed among arthropod taxa and functional groups. Several sap-sucking homopterans and hemipterans reached control levels within 2-4 wk of the treatment, whereas abundances of parasitoids and predators recovered to match control numbers only 6 wk after defaunation....
Biological invasions are one of the greatest threats to native species in natural ecological systems. One of the most successful invasive species is Bromus tectorum L. (cheatgrass), which is having marked impacts on native plant communities and ecosystem processes. However, we know little about the effects of this invasion on native animal species in the Intermountain West. Because ants have been used to detect ecological change associated with anthropogenic land use, they seem well suited for a preliminary evaluation of the consequences of cheatgrass-driven habitat conversion. In our study, we used pitfall traps to assess ant community assemblages in intact sagebrush and nearby cheatgrass-dominated vegetation....
Rising temperatures have begun to shift flowering time, but it is unclear whether phenotypic plasticity canaccommodate projected temperature change for this century. Evaluating clines in phenological traits and the extentand variation in plasticity can provide key information on assessing risk of maladaptation and developing strategiesto mitigate climate change. In this study, flower phenology was examined in 52 populations of big sagebrush (Artemi-sia tridentata) growing in three common gardens. Flowering date (anthesis) varied 91 days from late July to lateNovember among gardens. Mixed-effects modeling explained 79% of variation in flowering date, of which 46% couldbe assigned to plasticity and genetic variation...
thumbnail
Data are contained in a Microsoft Access database consisting of 27 data tables. Tables provided include emergency stabilization and rehabilitation (ESR) projects sampled, study plot characteristics, and sampled vegetation and fuels data. All data are from Bureau of Land Management (BLM) federal lands within the Great Basin region of the intermountain west.
Desert plants can influence the pattern of resources in soil resulting in small-scale enriched zones. Although conceptually simple, the shape, size, and orientation of these "resource islands" are difficult to study in detail using conventional sampling regimes. To demonstrate and alternative approach, we sampled soil under and around individual Artemisia tridentata (sagebrush), a dominant shrub of cool desert environments, and analyzed the samples with univariate statistics and geostatistics. Univariate Halvorson, Jonathan J, Harvey Bolton Jr, Jeffrey L Smith, and Richard E Rossi. ?Geostatistical analysis of resource islands under Artemisia tridentata in the shrub-steppe.? Western North American Naturalist 54,...
thumbnail
The exotic annual grass Bromus tectorum has replaced thousands of hectares of native perennial vegetation in semi-arid ecosystems of the western United States. Inorganic N availability and production were compared in soil from monodominant patches of Bromus tectorum, the perennial bunchgrass Elymus elymoides, and the shrub Artemisia tridentata, in Curlew Valley, a salt-desert shrub site in Northern Utah. Bromus-dominated soil had greater %N in the top 10 cm than Artemisia or Elymus-dominated soils. As determined by spring isotope-dilution assays, gross mineralization and nitrification rates were higher in Bromus-dominated than Artemisia-dominated soils, but gross rates of NH4+ and NO3- consumption were also higher....
There is increasing recognition that overall interactions among plant species are often the net result of both positive and negative effects. However, the positive influence of other plants has rarely been examined using detailed demographic methods, which are useful for partitioning net effects at the population level into positive and/or negative effects on individual vital rates. This study examines the influence of microhabitats created by the native shrubs Artemisia tridentata and Purshia tridentata on the demography of the invasive annual grass Bromus tectorum in the Great Basin Desert, California, USA. Shrub understory environments differed significantly from intershrub space and were characterized by higher...
map background search result map search result map Interaction of historical and nonhistorical disturbances maintains native plant communities Changes in the distribution and status of sage-grouse in Utah Inorganic N turnover and availability in annual- and perennial-dominated soils in a northern Utah shrub-steppe ecosystem Proportion of Big Sagebrush Land Cover (1-km scale) in the Wyoming Basins Ecoregional Assessment area Vegetation and fuels data collected in 2010 and 2011 from historical emergency stabilization & rehabilitation seedings (1990 – 2003) on BLM lands within the Great Basin Inorganic N turnover and availability in annual- and perennial-dominated soils in a northern Utah shrub-steppe ecosystem Interaction of historical and nonhistorical disturbances maintains native plant communities Changes in the distribution and status of sage-grouse in Utah Vegetation and fuels data collected in 2010 and 2011 from historical emergency stabilization & rehabilitation seedings (1990 – 2003) on BLM lands within the Great Basin Proportion of Big Sagebrush Land Cover (1-km scale) in the Wyoming Basins Ecoregional Assessment area