Elymus Lanceolatus Research Articles

English

The survival and growth of trees and shrubs in arid regions of the western U.S. is often limited by inadequate soil moisture availability during establishment. This four year study investigated plant growth and water conservation benefits associated with sub- surface water delivery via PVC pipes (sub-irrigation tubes) on two sites. The first test site was maintained fallow, and the second site with a cover of thickspike wheatgrass Elymus lanceolatus. Four species of woody plants (bur oak Quercus macrocarpa; green ash Fraxinus pennsylvanica; ponderosa pine Pinus ponderosa; and Rocky Mountain juniper Juniperus scopulorum) were tested in randomized complete block designs. The effects of water delivery method (surface-applied versus sub-irrigation tube) and herbaceous competition (fallow versus vegetated) on plant survival, height growth, and vigor rating were compared. In year one, sub-irrigation tubes did not result in significant improvements (ANOVA, LSD Separation, p=0.05) in survival or height growth of any species on either site, but did result in significantly better vigor rating in bur oak on the vegetated site. In year two of the study, only green ash on the fallow site demonstrated significantly better height growth and vigor rating where sub-irrigation tubes were used. In year three on the fallow site, bur oak had significantly greater height growth and green ash had significantly better vigor rating where sub-irrigation tubes were used. Additionally in year three, ponderosa pine on the vegetated site had significantly better height growth where tubes were used. In year four on the fallow site, green ash had significantly better vigor rating where tubes were used. There were no significant differences in survival of any species on either site as a result of water delivery method. With the exception of ponderosa pine in year one, each species by treatment had equal or greater survival, height growth, and vigor rating on the fallow versus the vegetated site. Results strongly support clean cultivation to increase the functional success of tree and shrub conservation plantings. In addition, sub-irrigation tubes may prove effective for some species depending on proximity to the seedlings root system, severity of drought, and other management practices.

English

Critical wildlife habitat supporting mule deer, antelope, and sage grouse in high elevation rangeland and sagebrush ecosystems of southwest Wyoming is threatened by energy development and residential sprawl, resulting in a declining forage base. Restoring disturbances with diverse plant communities is needed. Our objectives were to assess establishment and persistence of native grass, forb, and shrubs, and to test seed mixtures and seeding techniques. In October 2005, 72 entries of 50 native species were drill-seeded on a reclaimed well-pad site, in single-species plots in a randomized complete block design with four replications. Also, two seed mixtures were broadcast- and drill-seeded, and one seed mixture was hydroseeded on disturbed areas adjacent to the plots. In replicated plots, density of seeded species was recorded in each of the 3 years post-seeding, and biomass was clipped from grass plots in 2008. Density by species was counted in mixture plots. In replicated plots, ANOVA showed plant counts depended on seeded species. Of the grasses, densities of L-46 basin wildrye (72 plants/m 2 ), 'Sodar' streambank wheatgrass (47 plants/m 2 ), and 'Critana' thickspike wheatgrass (37 plants/m 2 ) were greater than other grasses; 'Appar' blue flax (11 plants/m 2 ), Richfield Eaton's and Old Works fuzzytongue penstemon (5 plants/m 2 ) were greater than other forbs; and 'Wytana' fourwing saltbush (7 plants/m 2 ), Snake River Plains fourwing saltbush (4 plants/m 2 ), and 9016134 Gardner's saltbush (1.4 plants/m 2 ) were greater than other shrubs. The most biomass was produced by L-46, Washoe, and 'Trailhead' basin wildryes, and Critana thickspike wheatgrass. Establishment of the broadcast-seeded Shell and Bridger mixtures were 140,923 and 78,309 plants/ha, respectively. Establishment of the drill-seeded Bridger and Shell mixtures were 45,865 and 34,706 plants/ha, respectively. The Shell mixture hydro-seeding was unsuccessful. Short-term results provide recommendations for native plant restoration. Relatively low establishment of forbs and shrubs indicate more work is needed to develop these plant materials and technologies.

Mineral concentration in selected native temperate grasses with potential use as biofuel feedstock

Stands of native grasses along roadways, in buffer strips, riparian zones and grass prairies have potential utility as feedstock for bioenergy production. The sustainability of harvesting these stands is reliant, in part, on knowledge of the mineral concentration of the harvested grasses because removal of mineral nutrients such as phosphorus (P) and potassium (K) can impact subsequent biomass production and ecosystem services associated with these stands. Mineral content of biomass, particularly that of silicon (Si), chlorine (Cl), and sulfur (S) also impacts thermochemical conversion approaches that convert grasses into bioproducts. This study quantified Cl, S, Si, P and K in Bromus marginatus, Elymus glaucus, Poa secunda, Pseudoroegneria, Elymus lanceolatus, Elymus trachycaulus, Leymus cinereus, Leymus triticoides, and Pseudoroegneria spicata collected at three growth developmental stages from four plant introduction stations located in the western US. Differences ( P ⩽ 0.05) in mineral concentrations were associated with developmental stage, species, and location. Variability was greatest in Si concentrations which ranged from 1847 to 28620 mg kg −1, similar to those recorded in other grasses. Variability in Cl and S concentrations also occurred, but at less magnitude than that of Si. Concentrations of P and K, two mineral fertilizer components, varied approximately threefold among these grasses. Differences in mineral concentrations among these grasses were not completely dependent upon soil mineral content. Long-term evaluations of available soil mineral concentrations under contrasting management practices are needed to quantify how local conditions impact mineral cycling, and in turn, the sustainability of harvesting these stands. The data presented here establish baselines for these species in locations subject to contrasting environmental and microbiological conditions that affect mineral cycling and availability.

Characterization of fitness traits in thickspike wheatgrass

Poor seed production and stand establishment are limitations to the use of thickspike wheatgrass [Elymus lanceolatus (Scribn. & J.G. Sm.) Gould] in rangeland re-vegetation projects. This study assessed the heritability of seed production, rhizome proliferation, and biomass production and genotypic correlations among these traits in a population of half-sib thickspike wheatgrass families at a site near Nephi, UT, USA during 2005 and 2006. Heritability estimates were ~ 0.6 for seed production and rhizome spread, but non-significant for biomass production. Genotypic correlations among the traits were all low or non-significant. Key words: Biomass production, genotypic correlation, heritability, rhizome, seed production, thickspike wheatgrass

INCREASED SENSITIVITY AND VARIABILITY OF PHYTOTOXICITY RESPONSES IN ARCTIC SOILS TO A REFERENCE TOXICANT, BORIC ACID

Industrial and human activities in the Arctic regions may pose a risk to terrestrial Arctic ecosystem functions. One of the most common terrestrial toxicological end points, primary productivity, typically is assessed using a plant phytotoxicity test. Because of cryoturbation, a soil mixing process common in polar regions, we hypothesized that phytotoxicity test results in Arctic soils would be highly variable compared to other terrestrial ecosystems. The variability associated with phytotoxicity tests was evaluated using Environment Canada's standardized plant toxicity test in three cryoturbated soils from Canada's Arctic exposed to a reference toxicant, boric acid. Northern wheatgrass (Elymus lanceolatus) not only was more sensitive to toxicants in Arctic soils, its response to toxicants was more variable compared to that in temperate soils. The phytotoxicity of boric acid in cryosols was much greater than commonly reported in other soils, with a boric acid concentration of less than 150 microg/g soil needed to inhibit root and shoot growth by 20%. Large variability also was found in the phytotoxicity test results, with coefficients of variation for 10 samples ranging from 160 to 79%. The increased toxicity of boric acid in cryosols and variability in test response was not explained by soil properties. Based on our admittedly limited data set of three different Arctic soils, we recommend that more than 30 samples be taken from each control and potentially impacted area to accurately assess contaminant effects at sites in northern Canada. Such intensive sampling will insure that false-negative results for toxicant impacts in Arctic soils are minimized.

BIOGEOCHEMICAL TOXICITY AND PHYTOTOXICITY OF NITROGENOUS COMPOUNDS IN A VARIETY OF ARCTIC SOILS

Ammonium nitrate (NH(4)NO(3)) is a common water pollutant associated with many industrial and municipal activities. One solution to reduce exposure of sensitive aquatic systems to nitrogenous compounds is to atomize (atmospherically disperse in fine particles) contaminated water over the Arctic tundra, which will reduce nitrogen loading to surface water. The toxicity of ammonium nitrate to Arctic soils, however, is poorly understood. In the present study, we characterized the biogeochemical toxicity and phytotoxicity of ammonium nitrate solutions in four different Arctic soils and in a temperate soil. Soil was exposed to a range of ammonium nitrate concentrations over a 90-d period. Dose responses of carbon mineralization, nitrification, and phytotoxicity endpoints were estimated. In addition to direct toxicity, the effect of ammonium nitrate on ecosystem resilience was investigated by dosing nitrogen-impacted soils with boric acid. Ammonium nitrate had no effect on carbon mineralization activity and only affected nitrification in one soil, a polar desert soil from Cornwallis Island, Northwest Territories, Canada. In contrast, ammonium nitrate applications (43 mmol N/L soil water) significantly impaired seedling emergence, root length, and shoot length of northern wheatgrass (Elymus lanceolatus). Concentrations of ammonium nitrate in soil water that inhibited plant parameters by 20% varied between 43 and 280 mmol N/L soil water, which corresponds to 2,100 to 15,801 mg/L of ammonium nitrate in the application water. Arctic soils were more resistant to ammonium nitrate toxicity compared with the temperate soil under these study conditions. It is not clear, however, if this represents a general trend for all polar soils, and because nitrogen is an essential macronutrient, nitrogenous toxicity likely should be considered as a special case for soil toxicity.

BIOGEOCHEMICAL TOXICITY AND PHYTOTOXICITY OF NITROGENOUS COMPOUNDS IN A VARIETY OF ARCTIC SOILS

Ammonium nitrate (NH(4)NO(3)) is a common water pollutant associated with many industrial and municipal activities. One solution to reduce exposure of sensitive aquatic systems to nitrogenous compounds is to atomize (atmospherically disperse in fine particles) contaminated water over the Arctic tundra, which will reduce nitrogen loading to surface water. The toxicity of ammonium nitrate to Arctic soils, however, is poorly understood. In the present study, we characterized the biogeochemical toxicity and phytotoxicity of ammonium nitrate solutions in four different Arctic soils and in a temperate soil. Soil was exposed to a range of ammonium nitrate concentrations over a 90-d period. Dose responses of carbon mineralization, nitrification, and phytotoxicity endpoints were estimated. In addition to direct toxicity, the effect of ammonium nitrate on ecosystem resilience was investigated by dosing nitrogen-impacted soils with boric acid. Ammonium nitrate had no effect on carbon mineralization activity and only affected nitrification in one soil, a polar desert soil from Cornwallis Island, Northwest Territories, Canada. In contrast, ammonium nitrate applications (43 mmol N/L soil water) significantly impaired seedling emergence, root length, and shoot length of northern wheatgrass (Elymus lanceolatus). Concentrations of ammonium nitrate in soil water that inhibited plant parameters by 20% varied between 43 and 280 mmol N/L soil water, which corresponds to 2,100 to 15,801 mg/L of ammonium nitrate in the application water. Arctic soils were more resistant to ammonium nitrate toxicity compared with the temperate soil under these study conditions. It is not clear, however, if this represents a general trend for all polar soils, and because nitrogen is an essential macronutrient, nitrogenous toxicity likely should be considered as a special case for soil toxicity.

Recommended seeding rates for reduced maintenance, turf-type wheatgrasses

Crested wheatgrass [Agropyron cristatum (L.) Gaertn.] has potential as a reduced-maintenance turfgrass, but seeding rates that assure rapid, uniform establishment are critical for success. 'Roadcrest,' CWG-R, and Chelkar breeding populations of crested wheatgrass, 'Sodar' streambank wheatgrass [Elymus lanceolatus (Scribn. & J.G. Sm.) Gould], and 'Gazelle' tall fescue (Festuca arundinacea Schreb.) were seeded at 0.5, 2.0, and 6.0 lb/1000 ft² in 1999. Plots were irrigated 50 to 60% EToreplacement, with 2 lb of N per 1000 ft² per year, and mowed at 3 inches. Higher seeding rates consistently had higher percent cover ratings than did lower seeding rates in 1999. By July of 2000 no differences existed between the 2.0 and 6.0 lb/1000 ft² seeding rates for turf quality, and percent cover, but both had higher ratings than the 0.5 lb/1000 ft² rates. Sodar, Chelkar, and tall fescue established faster, retained a denser stand, and better turf quality than Roadcrest and CWG-R. A seeding rate of 6.0 lb/1000 ft² is recommended for fastest establishment of wheatgrass cultivars in a low maintenance turf. A 2.0 lb/1000 ft² seeding rate could be used, but would likely need somewhat more maintenance and time to achieve a comparable stand.

Characterization of Amphiploid Hybrids between Bluebunch and Thickspike Wheatgrasses

An amphiploid derivative from hybrids between bluebunch wheatgrass (2n = 2x = 14) [Pseudoroegneria spicata (Pursh) A. Love] and thickspike wheatgrass (2n = 4x = 28) [Elymus lanceolatus (Scribner and Smith) Gould] was developed to compare cytological, morphological, anatomical, and seed characteristics between the triploid F1 hybrids (2n = 3x = 21) and their colchicine induced hexaploid (2n = 6x = 42) derivative (C0). The amphiploid population produced an average of 3.1 seeds spikelet−1 and pollen stainability averaged 85.5%. Seed set under self‐pollination in the amphiploids ranged from <1% to >99% with an average of 50%. Fifty‐eight of the 103 plants studied were hexaploid (2n = 6x = 42). The remaining plants had chromosomes ranging from 2n = 39 to 2n = 44 and were less fertile than the euploids. Meiosis in the euploid plants was regular and typical of a segmental autoallohexaploid St1St1St2St2HH. The most common meiotic chromosome configuration was 21 bivalents. A high frequency of bivalents and a low frequency of quadrivalents indicate that the St genomes of the two parental species have diverged. The amphiploids had thicker culms, more leaves per culm, and longer and wider leaves than either parental species. Multivariate analysis demonstrated that the amphiploids, though morphologically similar to the parental species, was distinct. In general, C0 hybrids were less vigorous than the F1 from which they were derived. Through amphiploidy, genetic introgression between the two species is possible.

Cytology and Fertility of Advanced Populations of Elymus lanceolatus (Scribn. & Smith) Gould × Elymus caninus (L.) L. Hybrids

Within the wheatgrasses and wildryes, amphiploids are frequently made as a means for introgressing desirable traits and restoring fertility in hybrids between diverse species. This study reports the cytology, fertility, and morphological characteristics of Elymus lanceolatus (Scribn. & Smith) Gould, E. caninus (L.) L., their F1 hybrids, advanced generations (F7 and F8), and three generations of advanced amphiploid progenies (C1, C2, and C3). Meiotic chromosome associations of E. lanceolatus and E. caninus are typical of allotetraploids. Chromosome pairing in the F1 hybrids suggests a close relationship between the two parents. Bivalent associations most frequently observed in the F7 and F8 were 14 bivalents. After multiple generations of harvesting available seed each generation from 10 plants, an increase in meiotic regularity was observed in the advanced F generations. Aneuploidy in the amphiploids (C generation) was observed in the C2 and C3 generations with chromosome numbers ranging from 47 to 56. The C1 generation had significantly fewer univalents per cell than the C2 and C3 generations. Combined across chromosome numbers, there was a significant decrease in the number of bivalents from 22.48 to 21.36 to 20.27 in each succeeding C generation, respectively. After seven generations of seed increase, pollen stainability increased from less than 1% in the F1 hybrid to 87 and 85% in the F7 and F8 generations, respectively. Chromosome doubling significantly reduced pollen stainability in the C1, C2, and C3 generations as compared to the parents and advanced F generations. Cluster analysis was able to separate the parents and the different hybrid populations.

Potential utilization of native prairie grasses from western Canada as ethanol feedstock

The utilization of native grass species for potential biomass feedstocks of the emerging ethanol industry requires more information about their cellulose and hemicellulose concentration. Ten native species were grown at seven sites across the prairie region of western Canada for two to four growing seasons. Northern wheatgrass, Elymus lanceolatus, produced high concentrations of cellulose (363 g kg-1) but low concentrations of hemicellulose (266 g kg-1). Green needlegrass, Nasella viridula, produced high concentrations of both constituents (351 and 307 g kg-1). Four warm-season grasses, big bluestem, Andropogon gerardii, little bluestem, Schizachyrium scoparium, prairie sandreed, Calamovilfa longifolia, and switchgrass, Panicum virgatum, had 346, 342, 340 and 338 g kg-1, respectively, concentrations of cellulose and also exhibited a positive response to temperature that resulted in increased hemicellulose concentration. Accumulated thermal time (degree day base 10°C) was correlated to hemicellulose concentrations in the warm-season grasses but not for cool-season grasses. Holocellulose (cellulose + hemicellulose) concentration differences varied among site-years but warm-season grasses were more stable in hollocellulose concentration than cool-season grasses. Key words: Biomass, native grasses, cellulose, hemicellulose, biofuel

Plant and soil responses to biosolids application following forest fire.

Soil stability and revegetation is a great concern following forest wildfires. Biosolids application might enhance revegetation efforts and enhance soil stability. In May 1997, we applied Metro Wastewater Reclamation District (Denver, CO, USA) composted biosolids at rates of 0, 5, 10, 20, 40, and 80 Mg ha(-1) to a severely burned, previously forested site near Buffalo Creek, CO to improve soil C and N levels and help establish eight native, seeded grasses. The soils on the site belong to the Sphinx series (sandy-skeletal, mixed, frigid, shallow Typic Ustorthents). Vegetation and soils data were collected for four years following treatment. During the four years following treatment, total plant biomass ranged from approximately 50 to 230 g m(-2) and generally increased with increasing biosolids application. The percentage of bare ground ranged from 4 to 58% and generally decreased with increasing biosolids rate. Higher rates of biosolids application were associated with increased concentrations of N, P, and Zn in tissue of the dominant plant species, streambank wheatgrass [Elymus lanceolatus (Scribn. & J.G. Sm) Gould subsp. lanceolatus], relative to the unamended, unfertilized control. At two months following biosolids application (1997), total soil C and N at soil depths of 0 to 7.5, 7.5 to 15, and 15 to 30 cm showed significant (P < 0.05) linear increases (r2 > 0.88) as biosolids rate increased. The surface soil layer also showed this effect one year after application (1998). For Years 2 through 4 (1999-2001) following treatment, soil C and N levels declined but did not show consistent trends. The increase in productivity and cover resulting from the use of biosolids can aid in the rehabilitation of wildfire sites and reduce soil erosion in ecosystems similar to the Buffalo Creek area.

Forage quality of seeded native grasses in the fall season on the Canadian Prairie Provinces

There is renewed interest in re-seeding native grasses in the prairie region of western Canada but there is limited information on their forage quality for fall grazing. We evaluated forage quality in early fall of nine native and one introduced grass species for 2 to 4 yr at five locations. The neutral detergent fiber (NDF) was high due to the advanced growth stage of the plants but varied among grass species at all sites . Western wheatgrass, Pascopyrum smithii, exhibited the lowest NDF and highest in vitro organic matter digestibility (IVOMD). Northern wheatgrass, Elymus lanceolatus, exhibited the highest crude protein while western wheatgrass ranked second highest for crude protein. Indiangrass, Sorghastrum nutans, exhibited the highest P and Ca concentrations, while green needle grass, Nasella viridula, and mammoth wildrye, Leymus racemosus, exhibited the lowest concentrations. Acid detergent fiber (ADF) was not highly correlated to IVOMD, presumably due to the mature phenological stage at sampling. Western wheatgrass forage was nutritionally adequate to maintain a dry beef cow during the second trimester of pregnancy. Other species did not “cure on the stem” as had been previously reported and would require supplementary energy and protein to be utilized for fall pastures. Key words: Forage quality, fiber, protein, P, C4 grasses, C3 grasses

Soil and plant response to wellsite rehabilitation on native prairie in southeastern Alberta, Canada

Rehabilitation of disturbed native prairie is a challenge facing many in the petroleum industry, with implications for prairie ecology and productivity. The purpose of this research was to examine the relative influence of four rehabilitation strategies on biogeochemical processes (i.e., nitrogen availability, plant uptake of nitrogen, biomass production, carbon allocation, and soil biological activity). Seven petroleum wellsites were selected on Chernozemic and Solonetzic soils in southeastern Alberta. Undisturbed native prairie was compared with four seeding treatments: not seeded, a low diversity seed mix commonly used by industry, a low diversity mix of species more typically dominant in native prairie, and a diverse seed mix. Flux of NO3− and NH4+were measured in situ using ion exchange membranes. Soil total C and N were lower and available N higher as a result of disturbance. In the seeded treatments, biomass production was higher and soil nitrogen flux was lower due to higher plant uptake than in the unseeded treatment. Higher initial N availability favoured species with rapid growth and colonization rates, particularly Agropyron dasystachyum [(Hook.) Scribn.] and Agropyron trachycaulum [(Link) Malte]. Seed mix composition and species attributes were deemed to have greater influence on N cycling and biomass production than seed mix diversity. Key words: Nitrogen cycling, plant competition, secondary succession, wheatgrass, biodiversity, prairie

Mixtures of Buffalograss and Fine Fescue or Streambank Wheatgrass as a Low-maintenance Turf

We investigated mixtures of buffalograss [Buchloë dactyloides (Nutt.) Engelm. `Texoka' and `Cody'] and fine fescue species (Festuca rubra ssp. rubra L. `Vista', F. ovina var. glauca Lam. `Minotaur', F. rubra ssp. commutata Gaud. `Jamestown II') or stream-bank wheatgrass [Agropyron riparium Scribn. &amp; Smith `Sodar'; syn. Elymus lanceolatus (Scribn. &amp; Smith) Gould subsp. lanceolatus] as a low-maintenance turf with low irrigation requirements and season-long green color and growth. Buffalograss plots in Logan, Utah, were overseeded with fine fescue and streambank wheatgrass at two seeding rates. Plots of fine fescue, wheatgrass, or buffalograss alone were also established. At 50% evapotranspiration (ETo) replacement, fine fescues dominated the mixtures with no differences due to seeding rates. Wheatgrass mixture plots were unacceptable in quality. Buffalograss control plots and mixtures were similar for turfgrass quality in August, and fine fescue controls and mixtures were similar in spring and fall. The mixtures performed well in the low-maintenance turf situation, but dominance of fine fescue over the buffalograss limits the potential of these specific mixtures.

Wyoming Big Sagebrush Density: Effects of Seeding Rates and Grass Competition

AbstractThe mining industry commonly seeds shrubs and grasses concurrently on coal‐mined lands of northeastern Wyoming, but ecological interactions between seeded shrubs and grasses are not well documented. Artemisia tridentata Nutt. ssp. wyomingensis (Beetle and Young) (Wyoming big sagebrush) is the dominant pre‐mining shrub on many Wyoming mine sites. Despite past failures to establish Wyoming big sagebrush, the Wyoming Department of Environmental Quality, Land Quality Division's rules and regulations require establishment of 1 shrub per m2 on 20% of post‐mined land in Wyoming. A study was established at the Belle Ayr Coal Mine south of Gillette, Wyoming to evaluate the effects of sagebrush seeding rates and grass competition on Wyoming big sagebrush seedling density. Three sagebrush seeding rates (1, 2, and 4 kg pure live seed [pls]/ha; 350, 700, and 1,400 pls/m2, respectively) and seven cool‐season perennial grass mixture seeding rates (0, 2, 4, 6, 8, 10, and 14 kg pls/ha; 0, 187, 374, 561, 750, 935, and 1,309 pls/m2, respectively) were applied during winter 1998–1999. Pascopyrum smithii (Rydb.) A. Love (western wheatgrass), Elymus lanceolatus (Scribner &amp; J.G. Smith) Gould (thickspike wheatgrass), and Elymus trachycaulus (Link) Gould ex Shinners (slender wheatgrass) comprised the grass seed mix (equal seed numbers of each species). Sagebrush seedling density differed among sagebrush seeding rates but not among grass seeding rates. On all sampling dates in 1999 and 2000, sagebrush seedling density differed among sagebrush rates and was greatest at the 4 kg pls/ha sagebrush seeding rate. All sagebrush seeding rates provided densities of at least 1 shrub per m2 after two growing seasons. Grass density and production in 2000 suggest that adequate grass production (75 g/m2) was achieved by seeding at 6 to 8 kg pls/ha. Within these grass seeding rates, four or more sagebrush seedlings per m2 were attained when sagebrush was seeded at 2 to 4 kg pls/ha. Use of these seeding rate combinations in mine reclamation can achieve Wyoming big sagebrush standards and reduce reseeding costs.

Preble's Shrew and Great Basin Pocket Mouse from the Centennial Valley Sandhills of Montana

tana sandhills habitat is poorly documented. During a 1999 faunal survey of the Centennial Valley Sandhills in Beaverhead County, extreme southwestern Montana, we captured specimens of Preble's shrew (Sorex preblei) and Great Basin pocket mouse (Perognathus parvus). Both are state Species of Concern (Montana Fish, Wildlife & Parks; Montana Natural Heritage Program) and are rarely collected in Montana. The Centennial Valley Sandhills are approximately 2 to 3 km wide and 14 km long (between 44'40'N, 111'42'W and 44'42'N, 111'49'W) at an average elevation of 2030 m; they are north of Lower and Upper Red Rock lakes near the east end of the Centennial Valley (Sonderegger and others 1982). The sandhills are small and generally stable dunes. Sandhills vegetation (Lesica and Cooper 1999) is a mixture of treeless successional types dominated by shrubs (Artemisia tridentata, A. tripartita, Chrysothamnus nauseosus, C. viscidiflorus, Tetradymia canescens), forbs (Lupinus argenteus, L. sericeus, Machaeranthera canescens, Opuntia fragilis, Phaecelia hastata, Psoralea tenuiflora) and grasses (Agropyron dasystachyum, Festuca idahoensis, Koeleria cristata, Poa nevadensis, Stipa comata). Standing water is absent within the sandhills proper, once winter snows melt in May, but is present south of the sandhills in nearby wetlands surrounding Upper and Lower Red Rock lakes. Shrews and pocket mice were collected from a series of 6 pitfall trap lines (10 stations, 30 m between stations, with a single can trap at each station; 60 cans total) and 3 drift-fence arrays (each with 4 pitfall can traps; 12 cans total). Pitfall lines were set 25 to 26 May 1999, and driftfence arrays were established on 25 May; each line and array was run continuously (except to clean and repair traps) until retrieved on 21 to 22 September (7000 trap-nights total on the pitfall lines and 1380 trap-nights total for the drift fence arrays). All pitfall can traps were in place for 115 to 117 nights of trapping. Traps were examined daily while we were at the sandhills (25 to 28 May, 28 June to 2 July, 28 to 30 July, 21 to 22 September), although no shrews or pocket mice were captured while we were present.

Ramet spacing of Elymus lanceolatus (thickspike wheatgrass) in response to neighbour density

Many plants exploit patchy resources through clonal foraging. Plants established in field plots were used to determine if Elymus lanceolatus ssp. lanceolatus (Scribner et J.G. Smith) Gould (thickspike wheatgrass) showed a clonal foraging response to neighbour densities, as it had previously shown to patchy soil nutrients. Neighbours consisted of the rhizomatous E. lanceolatus ssp. lanceolatus and the bunchgrass Elymus lanceolatus ssp. wawawaiensis (Scribner et Gould) J.R. Carlson et D.R. Dewey (proposed name), which are both native to the semiarid western U.S.A., and their ratios as well as total densities varied. Rather than an increase in spacing of exploratory ramets at high densities, as expected with clonal foraging, there was a decrease in spacing in both years of the experiment. Fewer target plants produced exploratory ramets at higher densities only in the second year. These reductions in exploratory clonal growth at higher neighbour densities, which were opposite to E. lanceolatus ssp. lanceolatus' response to low-resource patches, occurred perhaps because soil resource levels were too low overall to support rhizome production, and this condition was more pronounced in the second year. Physical resistance from neighbour roots perhaps also reduced rhizome production. However, rhizome growth may not be beneficial in such cases, and plants may be adapted to produce exploratory rhizomes only when some high-resource patches are encountered by the clone.Key words: clonal growth, competition, Elymus lanceolatus, plasticity, resource levels, rhizomes.

Ramet spacing of &lt;i&gt;Elymus lanceolatus&lt;/i&gt; (thickspike wheatgrass) in response to neighbour density

Ramet spacing of &lt;i&gt;Elymus lanceolatus&lt;/i&gt; (thickspike wheatgrass) in response to neighbour density

Investigation of Herbaceous Species Adapted to Snowfence Areas

Decreases in biomass and cover, as well as changes in species composition have occurred on rangelands affected by snowdrifts behind 3.8 meter tall Wyoming type snowfences along Interstate 80 in southeast Wyoming. Within the state of Wyoming, government agencies are responsible for the mitigation of any adverse effects associated with snowfences. These agencies need information which may aid mitigation efforts. In this study, 13 grass species and 2 tillage treatments (till and no-till) were evaluated in the field on both drift and non-drift areas, to determine the potential of each for the revegetation of snowfence sites. Evaluation was based on foliar cover at the end of the first growing season and aboveground biomass production after the second growing season. The project included plantings on 2 different soil depth sites ( 50 cm) that were treated as 2 separate experiments. Results indicate that pubescent wheatgrass 'Luna' (Elytrigia intermedia [Host] Nevski), thick-spike wheatgrass 'Critana' (Elymus lanceolatus [Scribn. &J.G. Smith] Gould), and 2 varieties of slender wheatgrass 'Pryor' and 'San Luis' (Elymus trachycaulus [Link] Gould ex Shinners), were superior in cover and aboveground biomass production when planted in combination with tilled plots. Tufted hairgrass (Deschampsia caespitosa [L.] Beauv.) exhibited the least potential for cover and aboveground biomass production. DOI:10.2458/azu_jrm_v53i4_perryman