Potential for controlling the spread of Centaurea maculosa with grass competition

Spotted knapweed ( Centaurea maculosa Lam.) is a major rangeland and roadside weed of the northern Rocky Mountains. It is often found in plant communities dominated by Pseudoroegneria spicatum or Festuca idahoensis , but it rarely invades roadsides dominated by Bromus tnermis Leyss. Aboveground biomass of the 3 grass species grown in mixture with Centaurea was compared to growth in monoculture at a range of nitrogen input levels. The results suggest that Bromus is capable of suppressing the growth of Centaurea with the degree of suppression increasing with increasing nitrogen levels. The 2 native grasses had no impact on Centaurea under the controlled environment conditions of this study.     

Selection of big sagebrush by sage grouse

Feeding sites of wintering sage grouse ( Centrocercus urophasianus ) were located, one each in stands of three subspecies of big sagebrush ( Artemisia tridentata : ssp. tridentata , basin; ssp. vaseyana , mountain; and ssp. Wyomingensis , Wyoming). Evidences of differential use of plants within subspecies were observed. Whole leaves from fed-on and nonfed-on big sagebrush plants were examined for intrasubspecies chemical comparisons of crude protein, phosphorus, in vitro digestibility, and monoterpenoids. No significant differences were detected except for in vitro digestibility of Wyoming fed-on and nonfed-on big sagebrush and monoterpenoid content of basin big sagebrush. Nutritive content of all three subspecies was high, which may in part help to explain wintering sage grouse weight gains.     

Parasites of the bowhead whale, Balaena mysticetus

Blood, tissue, and organ samples from five bowhead whales were examined for ecto- and endoparasites. Two species of protozoans, four genera of diatoms, one species of trematoda, two species of nematoda, and one species of amphipoda "louse" were found. No blood parasites were recovered. The larval anisakid nematode, found in the submucosa of the forestomach of one whale, generated a prominent inflammatory response. Protozoans found in contents of the colon included a flagellate and a sarcodinan. The sarcodinan, which was common in the colon contents of one whale, belongs to the genus Entamoeba and probably represents an undescribed species. Ogomogaster plicatus , a trematode, was also identified. The data from this study are compared with previous lists of parasites for the bowhead whale and two other species of baleen whales. From the results presented, the previous list of parasites for the bowhead whale has been expanded to include eight additional genera and species.     

Wintering mule deer preference for 21 accessions of big sagebrush

Wintering mule deer showed differential browsing preference among 21 accessions of big sagebrush ( Artemisia tridentata ) grown on gardens on three different mule deer herd ranges. The Hobble Creek accession of big sagebrush was significantly preferred over the other 20 accessions across all three sites and for all three years. Accessional preference means for the study period for all sites combined ranged from 28.3 to 57.5%. The data collected support the planned release of the Hobble Creek accession as a superior cultivar of big sagebrush for use on mule deer winter ranges. Plant coumarin content was primarily under genetic control, but site factors also had an effect. Assay for coumarin compounds is useful in determining subspecies of A. tridentata but not for precise prediction of mule deer browsing preference.     

In vitro digestibility of Kochia prostrata (L.) Schrad

In vitro digestibility was determined for 13 accessions of Kochia prostrata. Vegetative samples were collected in February and April. No significant differences in digestibility were detected due to month sampled or among accessions. The mean in vitro digestibility of the 13 accessions was 32.2% of dry matter digested. The accessional range was from 20.2 to 38.0% of dry matter digested.     

Parasites of Indochinese refugees entering Utah County, Utah: a two-year survey

A survey of parasites from 39 stool specimens taken from 36 Indochinese refugees who are now living in Utah County, Utah, indicated representative intestinal helminths (worms), and protozoans upon clinical examination. .Approximately 75% of the stools contained nematodes, and 55.5% had protozoans. Parasites found were Entamoeba coli, Chilomastix mesnili, Endolimax nana, Giardia lamblia, lodamoeba buetschlii, Clonorchis sinensis, Trichuris trichiura, Ascaris lumbricoides, and Plasinodium vivax. The most common protozoan observed was Entamoeba coli (1979 and 1980) while the most common helminths were Ascaris lumbricoides ) (1979) and Clonorchis sinensis (1980). These data were comparable to studies of refugees at two other laboratories in Utah and one at Washington, D.C.     

Winter nutrient content and deer use of gambel oak twigs in north central Utah

We examined winter nutritional quality of current-year bud and stem tissues from burned and unburned stands of Gambel oak ( Quercus gambelii Nutt.). Nutritional analyses were based on the amount of forage consumed by wintering mule deer. Deer use along the Utah Valley foothills averaged 6.25-10.7 cm of current-year growth. Of the tissues examined, post-fire bud tissue had the highest nutrient content, with a mean of 9.51% crude protein, 0.19% phosphorus, and 34.0% in vitro digestibility. Composite values (bud + stem) for unburned stands were slightly higher in crude protein and phosphorus and lower in digestibility than those reported in previous studies. Nutrient values from burned stands were significantly higher than those of unburned stands for all three measures. Tannin content of the burned-area regrowth was also higher. Overall forage value of Gambel oak to wintering mule deer is relatively low.     

Spotted knapweed distribution in stock camps and trails of the Selway-Bitterroot Wilderness

This article documents spotted knapweed ( Centaurea maculosa Lam.) in 30 campsites and along 5 trails in the Selway-Bitterroot Wilderness and assesses the role of disturbance and environmental factors in controlling infestation. Spotted knapweed was present in only 6 of 30 surveyed campsites and limited portions of all 5 trails that were sampled. All spotted knapweed in camps was below 1700 m elevation, in open canopy, and in areas with an opportunity class disturbance ranking of 3 or 4. Overall disturbance levels measured using U.S. Forest Service Site Impact Worksheets (SIWs) did not help predict occurrence of spotted knapweed, although bare mineral soil, vegetation loss, and development variables of SIWs provide some explanation of spotted knapweed presence or absence. There was no significant difference in knapweed frequency between areas used predominantly by horses and those use by humans within camps. Over 95% of spotted knapweed along trails was found within 0.5 km of the trailhead, occurred within 4.6 m of the trail, and had low reproductive potential. If the Bitterroot portion of the Selway-Bitterroot Wilderness is representative of forested wilderness areas in the Northern Rockies, then the perceived threat of spotted knapweed to wilderness areas may subsequently exceed the actual danger in many instances. Study findings indicated that managers should conduct surveys before initiating costly control measures in wilderness areas, that eradication may be a viable alternative when spotted knapweed numbers are this low, and that regulations promoting minimum-impact camping should reduce spotted knapweed infestation.