Randomly amplified polymorphic DNA analysis (RAPD) of Artemisia subgenus Tridentatae species and hybrids

Species of Artemisia (subgenus Tridentatae ) dominate much of western North America. The genetic variation that allows this broad ecological adaptation is facilitated by hybridization and polyploidization. Three separate studies were performed in this group using randomly amplified polymorphic DNA (RAPD). Fifty-seven 10-mer primers generated nearly 400 markers from genomic DNA obtained from leaf tissue. These studies were (1) a measure of the variability of plants within and between populations and between subspecies using 5 A. tridentata ssp. wyomingensis populations, 2 A. cana ssp. cana populations, and 1 A. cana ssp. viscidula population; (2) an examination of the hypothesis that tetraploid (4 x ) Artemisia tridentata spp. vaseyana derives de novo from diploid (2 x ) populations via antopolyploidy; and (3) an examination of the validity of the status of putative hybrids that have been produced by controlled pollination. These later hybrid combinations- A. tridentata ssp. tridentata × A. t. ssp. vaseyana , A. t. ssp. wyomingensis × A. tripartita , and A. cana ssp. cana A. tridentata ssp. wyomingensis - were made to combine traits of parental taxa in unique combinations with possible management application. RAPD marker data were subjected to similarity and UPGMA clustering analyses. RAPD markers were effective in measuring genetic diversity at different systematic levels. Individual plants within a population were approximately 55% to > 80% similar to one another; populations within subspecies gave corresponding values of similarity, probably a result of the combined effects of large population sizes and wind pollination. The 2 subspecies of A. cana were approximately 45% similar. At least some 4 x populations of A. tridentata ssp. vaseyana apparently derive de novo from 2 x plants based on their being embedded in 2 x phenogram groups, thus reinforcing evidence that autopolyploidy plays an important role in Tridentatae population biology. Two ( A. tridentata ssp. tridentata × A. t. ssp. vaseyana and A. cana ssp. cana × A. tridentata ssp. wyomingensis ) of the 3 putative hybrid combinations were confirmed to include hybrids. These hybrids may have potential in management applications. Additional use of RAPD technology combined with other techniques may be useful in delimiting genetic characteristics and in guiding artificial selection in Tridentatae .     

Lahontan sagebrush ( Artemisia arbuscula ssp. longicaulis ): a new taxon

A new subspecies of Artemisia arbuscula is described, A. arbuscula ssp. longicaulis Winward & McArthur, ssp. Nov. This taxon is a landscape dominant in portions of northwestern Nevada and adjacent California and Oregon at elevations from 1050 to 2000 m on shallow or argillic (clayey) soils. It differs from A. arbuscula ssp. arbuscula in its long floral stalks and large leaves. Morphological, chemical, ecological, and cytological data suggest that it is of hybrid origin. It is hexaploid (6x). We hypothesize that 2x A. arbusucla ssp. arbusucla and 4x A. tridentata ssp. wyomingensis are its parents.     

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.     

Mule deer foraging preference among five sagebrush ( Artemisia L.) taxa

The hypothesis that sagebrush taxa are equally utilized by mule deer ( Odocoileus hemionus hemionus ) on winter range was tested. Five taxa were studied for 10 years at 2 locations. The taxa were Artemisia tridentata ssp. tridentata (basin big sagebrush), A. t. ssp. wyomingensis (Wyoming big sagebrush), A. t. ssp. vaseyana (mountain big sagebrush), A. tripartita ssp. tripartita (tall threetip sagebrush), and A. arbuscula ssp. arbuscula (low sagebrush). Possible mule deer preferences were determined each year individually for the 2 sites. Utilization was high enough to conclude all taxa are important forage, but not excessive enough to mask preference. Artemisia tridentata ssp. vaseyana (34.4%) and A. arbuscula ssp. arbuscula (35.6%) were preferred over A. t. ssp. wyomingensis (10.9%) and A. t. ssp. tridentata (6.8%) at the Ashbough site. At the Scudder site there were few differences in preference for A. t. ssp. vaseyana (32.1%), A. t. ssp. wyomingensis (28.8%), and A. tripartita ssp. tripartita (32.0%). While ungulates often demonstrate a preference among taxa, all sagebrush taxa are a potentially valuable forage source.     

Correlation of neighborhood relationships, carbon assimilation, and water status of sagebrush seedlings establishing after fire

Interactions of Artemisia tridentata ssp. vaseyana (mountain big sagebrush) and neighboring herbs may affect community development following fire in sagebrush steppe. Dry mass, photosynthesis, and water relations were measured for seedlings of A. tridentata ssp. vaseyana occurring at different distances from neighboring herbs in the initial growing seasons following fire, when herbs dominate plant community cover. Seedling mass significantly increased as distance to neighboring herbs increased, although a low r 2 indicated that mass was also affected by other sources of variation. Carbon assimilation ( A net ) was also greater for A. tridentata ssp. vaseyana seedlings in microsites farther from herbs, except during those sampling dates when A net and water availability were at low levels. Contrary to our expectations, water status of seedlings was not correlated with their distances to neighboring herbs, and supplemental watering did not affect the slope of the relationship between seedling mass and distance to neighboring herbs. These findings suggest that negative relationships between A. tridentata ssp. vaseyana seedlings and herbs establishing after fire are not likely due to competition over water and may instead result from interactions over factors not measured here (e.g., nutrients).     

Vegetation characteristics of mountainous northeastern Nevada sagebrush community types

Vegetation characteristics of 15 sagebrush community types identified on the Humboldt National Forest, northeastern Nevada, are described. A total of 218 plant species were found over the 372 relatively undisturbed rangeland communities sampled. The dominant plant families encountered were the Asteraceae (45 taxa), Poaceae (32 taxa), Scrophulariaceae (14 taxa), and the Fabaceae (12 taxa). Average annual dry weight production of the community types ranged from about 400 kg/ha/yr on types with Artemisia nova as the dominant sagebrush species to 1,200 kg/ha/yr on some A. tridentata ssp. vaseyana community types. A general increase in species richness and vegetation plus litter ground cover was observed within community types as the dominant sagebrush species changed from A. nova to A. arbuscula to A. longiloba to A. tridentata spp. tridentata to A. tridentata ssp. vaseyana . Major differences in plant species production and constancy exist between the sagebrush community types studied.     

A sagebrush community type classification for mountainous northeastern Nevada rangelands

Vegetation characteristics of 15 sagebrush community types identified on the Humboldt National Forest, northeastern Nevada, are described. A total of 218 plant species were found over the 372 relatively undisturbed rangeland communities sampled. The dominant plant families encountered were the Asteraceae (45 taxa), Poaceae (32 taxa), Scrophulariaceae (14 taxa), and the Fabaceae (12 taxa). Average annual dry weight production of the community types ranged from about 400 kg/ha/yr on types with Artemisia nova as the dominant sagebrush species to 1,200 kg/ha/yr on some A. tridentata ssp. vaseyana community types. A general increase in species richness and vegetation plus litter ground cover was observed within community types as the dominant sagebrush species changed from A. nova to A. arbuscula to A. longiloba to A. tridentata spp. tridentata to A. tridentata ssp. vaseyana . Major differences in plant species production and constancy exist between the sagebrush community types studied.     

Planting depth of 'Hobble Creek' mountain big sagebrush seed

We conducted a greenhouse study in which 'Hobble Creek' mountain big sagebrush ( Artemisia tridentata ssp. vaseyana ) seeds were planted at various depths in soil to determine the optimal planting depth. Results showed that the optimal planting depth is 5 mm or less.     

Chrysothamnus nauseosus ssp. iridis (Asteraceae): a new endemic from Utah

Chrysothamnus nauseosus ssp. uintahensis (Asteraceae) is formally described and illustrated. The new subspecies represents stabilized hybrids that most probably have C. nauseosus ssp. hololeucus x C. parryi ssp. attenuatus ancestry. Morphological and anatomical comparisons are made among the putatively related taxa.        

Morphology of ephemeral and persistent leaves of three subspecies of big sagebrush grown in a uniform environment

Measurements were made of morphological characteristics of ephemeral and persistent leaves of three subspecies of big sagebrush ( Artemisia tridentata Nutt.) grown in a uniform environment. No morphological feature clearly separated the subspecies. Genetic - environmental interactions on leaf morphology apparently reduce its value as a sole criterion for distinguishing the subspecies.       

Chrysothamnus nauseosus ssp. uintahensis: a stabilized hybrid

Chrysothamnus nauseosus ssp. uintahensis (Asteraceae) is formally described and illustrated. The new subspecies represents stabilized hybrids that most probably have C. nauseosus ssp. hololeucus x C. parryi ssp. attenuatus ancestry. Morphological and anatomical comparisons are made among the putatively related taxa.        

Subspecies specificity of gall forms on Chrysothamnus nauseosus

Galls induced by tephritid flies (Diptera: Tephritidae) on Chrysothamnus nauseosus ssp. albicaulis, consimilis, graveolens, and salicifolius are useful in taxonomic identification of these subspecies in Utah. In this study, “callus” galls were found almost exclusively on ssp. albicaulis. “Cotton” galls were more frequent on ssp. consimilis and graveolens. “Mace” galls occurred on all four subspecies but were the only gall found on naturally occurring populations of ssp. salicifolius. Gall form specificity is not as well correlated with C. nauseosus subspecies in peripheral areas of the species range as in Utah. This decrease in specificity may be due to decreased competition for the host plant in outlying areas.     

Applicability of the universal soil loss equation for southeastern Idaho wildlands

Soil physical and chemical properties were studied to identify habitat differences among 15 sagebrush dominated plant community types of the Great Basin. The sagebrush taxa studied followed an apparent gradient of increasing soil fertility, with Artemisia nova commonly occupying the lowest fertility sites. Sites of moderate soil fertility tended to support A. arbuscula , A. longiloba , and A. tridentata ssp. Wyomingensis . Artemisia tridentata ssp. Tridentata and A. tridentata ssp. Vaseyana were commonly found on sites with the highest soil fertility levels as indicated by maximum organic carbon, nitrogen, and phosphorus levels within such soils. Mollic epipedon depth, total depth, and water-holding capacity of the soil also increased as the dominant sagebrush taxon of a community type changed from A. nova to A. tridentata ssp. Vaseyana . Data from this study provide information concerning soil relationships within relatively undisturbed rangeland communities. Such data are required if future soil sampling efforts within the Great Basin are to have a basis for comparison.     

Development and longevity of ephemeral and perennial leaves on Artemisia tridentata Nutt. ssp. wyomingensis

Big sagebrush ( Artemisia tridentata Nutt.) is one of the most successful plants in the Great Basin based on its abundance and wide distribution. The development of dimorphic leaves may be an important mechanism attributing to its adaptive and competitive abilities. Development, persistence, and proportions of ephemeral and perennial leaves on Wyoming big sagebrush ( Artemisia tridentata Nutt. ssp. wyomingensis ) were studied for two years. The large ephemeral leaves are the first to develop in early spring. As early developing ephemerals mature and stems elongate, new ephemeral and perennial leaves develop in the axes of these large ephemerals. Perennial leaves expanded in the summer of their first growing season, persisting on the shrub until their abscission during summer drought of the second growing season. Plants maintained 33% of their leaf weight through the winters of 1985 and 1986. Active leaf and stem growth occurred at soil water potentials above –0.2 MPa.     

Soil characteristics of mountainous northeastern Nevada sagebrush community types

Soil physical and chemical properties were studied to identify habitat differences among 15 sagebrush dominated plant community types of the Great Basin. The sagebrush taxa studied followed an apparent gradient of increasing soil fertility, with Artemisia nova commonly occupying the lowest fertility sites. Sites of moderate soil fertility tended to support A. arbuscula , A. longiloba , and A. tridentata ssp. Wyomingensis . Artemisia tridentata ssp. Tridentata and A. tridentata ssp. Vaseyana were commonly found on sites with the highest soil fertility levels as indicated by maximum organic carbon, nitrogen, and phosphorus levels within such soils. Mollic epipedon depth, total depth, and water-holding capacity of the soil also increased as the dominant sagebrush taxon of a community type changed from A. nova to A. tridentata ssp. Vaseyana . Data from this study provide information concerning soil relationships within relatively undisturbed rangeland communities. Such data are required if future soil sampling efforts within the Great Basin are to have a basis for comparison.     

Notes on the genus Bombylius Linnaeus in Utah, with key and descriptions of new species (Diptera: Bombyliidae)

A key to the Utah species of Bombylius is presented. Bombylius heximaculatus, nigriventris, montanus, abdominalis, aestivus, and auriferoides, new species, and lancifer kanabensis, subspecies new, are described from Utah. Bombylius lassenensis, new name, is proposed to replace the preoccupied B. pallescens Johnson and Maughan.         

A new combination in Penstemon (Scrophulariaceae)

Field and herbarium studies of Penstemon cyananthus Hook. ssp. longiflorus Pennell suggest that this taxon be elevated to species rank.       

Big sagebrush ( Artemisia tridentata vaseyana ) and longleaf snowberry ( Symphoricarpos oreophilus ) plant associations in northeastern Nevada

Artemisia tridentata/Symphoricarpos oreophilus and Symphoricarpos oreophilus/Artemisia tridentata  plant associations were studied in northeastern Nevada. A 60-stand reconnaissance followed by a detailed study of 37 stands differentiated five important habitat types using an association table approach. Data reduction with DECORANA and TWINSPAN also described five plant associations that were differentiated by species occurrence and geographical distribution. All stands were found at elevations between 2,200 and 3,100 m in areas where snow accumulates and is late to melt. Stands are found on 15 families of soils that are relatively deep, often skeletal, dark colored, and productive. The dominant perennial grasses included Agropyron spicatum, Agropyron trachycaulum, and Festuca idahoensis.