Treesearch

Atriplex canescens and A. acanthocarpa from the Chihuahuan Desert in Mexico were subjected to different salinity and irrigation treatments in a greenhouse study. Plants were grown in pots containing soil and irrigated with NaCl solutions of 0, 50, and 100 mM at 40 and 80 percent available soil water. Aerial biomass of A. canescens declined as NaCl treatments increased. In contrast, the aerial biomass of A. acanthocarpa was not negatively affected by the salinity treatments, suggesting a high salt tolerance of this species. Aerial biomass of A. acanthocarpa was more reduced by the decrease...

Managers need more efficient means of monitoring changes on the lands they manage. Accordingly, a new Australian approach was field tested and compared to the Daubenmire method of assessing plant cover, litter, and bare soil. The study area was a 2 mile wide by 30.15 mile long strip, mostly covered by salt desert shrub ecosystem types, centered along the SE boundary of the Eagle Bombing Range in NW Utah. Paired T analyses were used to see what differences in condition could be detected between Bureau of Land Management and U.S. Air Force lands occupying the same ecological sites. Because...

Cryptogamic crusts are communities composed of lichens, cyanobacteria, algae, mosses, and fungi. These integrated soil crusts are susceptible to disturbance, but if intact, appear to play a role in providing nutrients, especially nitrogen, to higher plants. It is not known how or under what conditions desert crusts can grow. Crust samples from localities on the Colorado Plateau and the Great Basin were brought to the laboratory and exposed to atmospheres of different humidity and different levels of liquid water. Both metabolic heat rate (q) and carbon dioxide evolution rate (RCO2) were...

Eurotia lanata (Pursh) Moq. (winterfat) is a boreal cold-desert subshrub, seldom more than 2 feet tall, that thrives in dry climates at cool temperatures. Diaspore collections from Matador, Saskatchewan, Canada; Pine Bluffs, Wyoming; and Sterling, Colorado, were cleaned and placed on moistened filter paper in petri dishes maintained at 0, 5, 10, 15, and 20 °C to study germination. Seeds germinated at all temperatures but seedlings were not acclimated to cold by germination temperature. At radicle emergence (ca. 3 mm), seeds were placed in calorimeter ampules. Heat-rate (q) was measured at...

Of the world’s land area, about 7 percent is salt affected. Irrigated land is more susceptible to salinity and it is estimated that over 1/3 of the irrigated soils are becoming saline. Certain plants (halophytes) grow well on high saline soils. One approach would be to grow halophytes on high saline soils and harvest their seeds. The oil in the seeds would be extracted for cooking oil. The amount of unsaturated fatty acids is a measure of the quality of cooking oil. High-unsaturated fatty acid content is considered a factor in preventing heart diseases. Seeds of seven halophytic shrubs...

Mycorrhizal fungi enhance the nutrition and survival of host plants in native ecosystems. Arid rangelands severely challenge plants because of chronic nutrient and water stress. Fourwing saltbush, Atriplex canescens (Pursh) Nutt., a dominant and important shrub of western arid rangelands, generally considered to be non-mycorrhizal, is more extensively colonized by dark septate (DS) fungal endophytes than by traditional mycorrhizal fungi. Roots of fourwing saltbush colonized by DS fungi were stained with sudan IV and analyzed with differential interference microscopy that revealed extensive...

Purshia tridentata (antelope bitterbrush), Ceanothus velutinus (snowbrush), Ceanothus sanguenius (redstem ceanothus), and Shepherdia canadensis (buffaloberry) are native shrubs of the Northern Intermountain Region that are generally characterized as nitrogen-fixing species. These species occupy a range of habitats from steppe to alpine environments. Nodulation of these species is initiated through root infection by Frankia species and the resulting nodules are described as coralloid. Nodulation is not necessarily confirmation that nitrogen-fixation is taking place in the nodular and root...

Total available carbohydrate (TAC) storage and depletion was measured in late summer and fall burned and unburned serviceberry (Amelanchier alnifolia). The purpose of the study was to assess the influence of late season prescribed fire on the vigor of serviceberry, a key browse species on white-tailed deer (Odecoileus virginianus ochrourus) winter range in northeastern Washington. All plants displayed similar TAC cycles through the first growing season following treatment. TAC levels in stems were highest prior to bud activity and declined during the early stages of growth (March, April,...

Sand sagebrush (Artemisia filifolia) is a dominant shrub on sandy soils throughout the Great Plains and Southwest. Sand sagebrush is reported to reduce wind erosion and provides valuable forage and cover to numerous wildlife species. However, the fire ecology of sand sagebrush is not well understood. Our objectives were to evaluate fire-induced mortality, occurrence of resprouting, and changes in sand sagebrush canopy structure and total nonstructural carbohydrates (TNC) following fall and spring prescribed burns. We selected twelve 4-ha plots on sand sagebrush-dominated sites in high-seral...

Saltcedar (Tamarix spp) has invaded nearly one million acres of riparian ecosystems in the southwestern U.S., displacing many native species. The objectives of this study were to estimate saltcedar mortality to summer wildfire, summer wildfire followed by rollerchopping, and dormant season treatment with 25 percent triclopyr to regrowth following a summer wildfire at Lake Meredith National Recreation Area. In July 1998, more than 100 acres of saltcedar-infested riparian area were burned. In February and March of 1999, regrowth of 200 dormant saltcedar trees were treated with 25 percent...