Atriplex Gardneri Research Articles

Assessment of the prospects of growing perennial grasses on landfills

Nineteen species of agricultural plants, recommended for cultivation in arid conditions of the USA, were tested on the dumps of the Ekibastuz coal mine. The most promising was Atriplex gardneri var. aptera - a North American plant that naturally inhabits the steppe regions of the USA. The group of promising species includes Leymus racemosus, Elymus trachycaulus, and Psathirostachys jnceus. Less promising species for biological reclamation include Calamovilfa longifolia, Bouteloua gracilis, Andropogon gerardii, Leymus arenarius, Pascopyrum smithii sv. Rosana, Pascopyrum smithii sv. Rodan, Elymus lanceolatus, Elytrigia intermedia, Agropyron cristatum, Atriplex canescens, Festuca ovina, and Elimus sibiricus. Lowly promising and unpromising species include Panicum virgatum, Agropyron cristatum x A. desertorum, Schizachyrium scoparium, and Bouteloua curtipendula. These plants are either not frost-resistant or cannot tolerate drought on the dumps.

Diet selection, commonness, and rarity in a pair of smooth-toothed pocket gophers

Abstract Understanding the determinants of species rarity is a perennial challenge for ecologists and conservation biologists. In addition to resource specialization, competitive interactions may limit the abundance and distribution of species, thereby accentuating rarity. However, resource partitioning can reduce or altogether offset such competitive effects, and thus permit species to thrive alongside more common, widespread competitors within a narrow range of environmental conditions. In south-central Wyoming, the Wyoming Pocket Gopher (Thomomys clusius) is restricted to areas dominated by Gardner’s Saltbush (Atriplex gardneri); it inhabits a geographic range that is entirely encompassed by a relatively abundant and widespread congener (T. talpoides, the Northern Pocket Gopher). However, the consumer–resource dynamics underlying the relationships among Wyoming pocket gophers, northern pocket gophers, and Gardner’s Saltbush are poorly understood. We assessed one dimension of consumer–resource interactions—diet selection—between Wyoming pocket gophers, northern pocket gophers, and Gardner’s Saltbush, using a combination of path analysis, DNA metabarcoding, and cafeteria-style feeding experiments. We rejected the null hypothesis that Wyoming pocket gophers and Gardner’s Saltbush co-occur solely because they require similar soil conditions. Although we could not distinguish between obligate and facultative specialization by Wyoming pocket gophers, the checkerboard-like distributions of these two Thomomys likely reflect the outcome of selection and avoidance of Gardner’s Saltbush. We suggest that Wyoming pocket gophers can persist within their small geographic range by capitalizing on Gardner’s Saltbush, a halophyte that probably requires some combination of physiological, morphological, and behavioral adaptations to exploit. Low abundances, restricted geographic ranges, or both are hallmarks of rarity, each of which are shaped by diet selection and other consumer–resource interactions. Quantifying consumer–resource interactions can therefore provide a mechanistic basis for the further refinement and testing of hypotheses on the abundance and distribution of closely related species.

Salinity Reduces the Forage Quality of Forage Kochia: A Halophytic Chenopodiaceae Shrub

Forage kochia (Bassia prostrata [L.] A.J. Scott) is a perennial, halophytic Chenopodiaceae shrub adapted to semiarid rangelands and steppes. It is noted for its ability to produce edible forage in saline environments, but the effect of salinity on its nutritive value has not been determined. Therefore, this study evaluated the dose-response of increasing salinity on the forage quality of forage kochia and Gardner’s saltbush (Atriplex gardneri [Moq.] D. Dietr., a chenopod forage shrub indigenous to the United States). Individual plants were evaluated in hydroponics for 28 days at 0, 150, 300, and 600 mM NaCl. Salt from accumulated ions, minerals, and forage nutritive value were determined using ground shoot samples. Analysis of forage nutritive value is problematic in plants with high salt concentrations, so neutral detergent fiber (NDF) and in vitro true digestibility (IVTD) were also predicted on an ash-corrected dry matter (DM) basis (NDFcorrected and IVTDcorrected). Forage kochia exhibited a dose-response for salt concentration, IVTDcorrected, and crude protein (CP) as salinity increased. Salt concentrations increased to 19% of DM at 600 mM NaCl, which may reduce voluntary intake by ruminants grazing forage kochia. Results indicated that uncorrected IVTD estimates were inflated as forage kochia IVTDcorrected decreased from 65% to 56% with the major change between 300 and 600 mM NaCl. Crude protein did not differ between two forage kochia cultivars but decreased from 26% to 15% between 0 and 600 mM NaCl, whereas Gardner’s saltbush CP decreased by only five percentage points as salinity increased. Nonetheless, despite the greater CP sensitivity to salinity level, forage kochia salt concentration was less and digestibility and metabolizable energy (ME) were greater than Gardner’s saltbush. Overall, salinity reduced the forage quality of forage kochia, though not as dramatically as for Gardner’s saltbush, thus supporting use of forage kochia to improve the forage base of saline rangelands.

Salinity tolerance of three competing rangeland plant species: Studies in hydroponic culture.

Halogeton (Halogeton glomeratus) is an invasive species that displaces Gardner's saltbush (Atriplex gardneri) on saline rangelands, whereas, forage kochia (Bassia prostrata) potentially can rehabilitate these ecosystems. Salinity tolerance has been hypothesized as the predominant factor affecting frequency of these species. This study compared relative salinity tolerance of these species, and tall wheatgrass (Thinopyrum ponticum) and alfalfa (Medicago sativa). Plants were evaluated in hydroponics, eliminating the confounding effects of drought, for 28 days at 0, 150, 200, 300, 400, 600, and 800 mmol/L NaCl. Survival, growth, and ion accumulation were determined. Alfalfa and tall wheatgrass shoot mass were reduced to 32% of the control at 150 mmol/L. Forage kochia survived to 600 mmol/L, but mass was reduced at all salinity levels. Halogeton and Gardner's saltbush increased or maintained shoot mass up to 400 mmol/L. Furthermore, both actively accumulated sodium in shoots, indicating that Na+ was the principle ion in osmotic adjustment, whereas, forage kochia exhibited passive (linear) Na+ accumulation as salinity increased. This study confirmed the halophytic nature of these three species, but, moreover, discovered that Gardner's saltbush was as saline tolerant as halogeton, whereas, forage kochia was less tolerant. Therefore, factors other than salinity tolerance drive these species’ differential persistence in saline‐desert ecosystems.

Thomomys clusius(Rodentia: Geomyidae)

Abstract: Thomomys clusius Coues, 1875 is a geomyid commonly called the Wyoming pocket gopher. Despite a varied taxonomic history, T. clusius is now recognized as a distinct species and as the smallest of 12 species in the genus Thomomys. The species is endemic to Wyoming, where it is restricted to about 1.97 million ha in the southern part of the state. T. clusius is often found in flat areas characterized by Gardner's saltbush (Atriplex gardneri) and fine-textured soils. Although the United States Fish and Wildlife Service concluded in 2010 that listing under the Endangered Species Act was not warranted, state and federal agencies continue to recognize T. clusius as a sensitive species due to its limited distribution and population size.

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.

The potential of legume-shrub mixtures for optimum forage production in southwestern Saskatchewan: A greenhouse study

Grazing in fall and early winter decreases the cost of beef production in southwe stern Saskatchewan. This grazing system can be improved by utilizing legume and native shrub species, which exhibit high nutritive value in the fall. To realize the system's full potential, a better understanding of optimum mixtures of legumes and shrubs is required. A greenhouse study was conducted to optimize mixtures of legumes and shrubs for economical pasture production. The first goal was to obtain better understanding of synergy from mixtures of legumes and native shrubs. The second goal was to estimate the changes in soil quality caused by growing legumes and shrubs in monocultures or mixtures. Legume species studied were: alfalfa (Medicago sativa L.) (Alf), purple prairie clover [Petalostemon purpureum (Vert.) Rydb] (Pr Cl) and American vetch (Vicia americana Muhl.) (Vetch); shrubs were: winterfat [Krascheninnkovia lanata (Pursh) Guldenstaedt] (Wf) and Gardner's saltbush [Atriplex gardneri (Moq.) D. Dietr.] (Sb). Treatments consisted of five monocultures, six mixtures and a control. Data on plant biomass, forage quality and soil quality parameters indicate that legume and shrub mixtures of Alf + Wf and/or Alf + Sb can potentially provide diversified forage sources, extended grazing periods and higher or similar yields with enhanced or similar forage quality than when grown separately. Key words: Legume, native shrub, forage production, forage quality, winterfat, saltbush

Evaluation of Revegetation Techniques of a Saline Flue Gas Desulfurization Sludge Pond

AbstractCodisposal of flue gas desulfurization (FGD) sludge with low‐volume generating station waste simplifies disposal but creates a saline, high‐boron (B) waste that may be difficult to revegetate after site closure. Studies on a delta of waste material in a codisposal pond in eastern Arizona evaluated management techniques, amendments, and plants for revegetating this material. One study investigated leaching and ridging techniques and a second evaluated amendment with manure, wood shavings, and fly ash. Four salt‐tolerant grass species and four saltbushes (Atriplex spp.) were evaluated in the two studies. Criteria for success were high survival rates and growth, as measured by grass height and shrub height × width. Leaching salts and B from the waste was not necessary for establishment and growth of transplanted shrubs and grasses. Ridging was not a successful technique, due to limited moisture and high levels of salinity and B on these structures. Gardner saltbush [A. gardneri (Moq.) D. Dietr.] and a fourwing saltbush [A. canescens (Pursh) Nutt.] accession from the site were the most successful shrubs and alkali sacaton [Sporobolus airoides (Torr.) Torr. ‘Saltalk‘] was the most successful grass at this disposal pond. Amendment with manure, wood shavings, or fly ash did not increase plant survival. Growth of grasses was improved with all amendments and was greatest with manure, but growth of shrubs was not improved with any amendment.

Plant Species for Revegetation of a Saline Flue Gas Desulfurization Sludge Pond

AbstractCodisposing saline wastewater from electrical generating stations with flue gas desulfurization (FGD) scrubber sludge simplifies waste disposal but produces a saline waste that will later require revegetation. This waste is low in macronutrients, contains high levels of salts and B, and has a fine texture. This study identified plants, based on germination test results, that show promise for sowing at an evaporation pond in eastern Arizona where scrubber sludge and wastewater are codisposed. Forty‐four grass, forb, and shrub accessions germinated on filter paper in saline water from the disposal pond. Dilutions of disposal pond water with untreated well water from the site ranged in EC from 0.17 to 3.03 S m−1. Our criteria for evaluating plants to be used in revegetating saline FGD sludge were: (i) ability to germinate in increasing levels of disposal pond water and (ii) ease of establishment from seed. The percentage of pond water that would reduce germination to 50% that of well‐water controls (P50) ranged as high as >100 for the most tolerant plants. Accessions that show promise for sowing at these types of saline waste disposal sites include: Elytrigia pontica ‘Jose’ and ‘Largo’, Atriplex gardneri, Puccinellia airoides, P. distans ‘Fults’, Festuca arundinacea ‘Alta’ and ‘Fawn’, Krascheninnikovia lanata, Kochia prostrata ‘Immigrant’, Panicum virgatum ‘Nebraska 28’, Sporobolus airoides ‘Saltalk’, Leymus angustus ‘Praireland’ and Elymus trachycaulus ‘Pryor’.

Carbon Source of Va Mycorrhizal Fungi Associated with Chenopodiaceae from a Semiarid Shrub‐Steppe

The mycorrhizal status of members of the Chenopodiaceae is of interest both from an evolutionary and an ecological perspective. Early surveys reported that weedy annuals in the Chenopodiaceae did not form mycorrhizal associations (Stahl 1900, Nicolson 1960). Others (e.g., Williams et al. 1976) suggested that perennial Atriplex shrubs were mycorrhizal, as occasional vesicles and hyphae were observed or the plants showed growth and survival responses to the addition of vesicular-arbuscular (VA) mycorrhizal fungi. Hirrel et al. (1978) concluded that plants in the Chenopodiaceae and Cruciferae were nonmycorrhizal because they observed no arbuscules, the exchange organs linking hosts and fungus, when plants were inoculated with VA mycorrhizal fungi. Allen (1983) argued that Atriplex gardneri was VA mycorrhizal as arbuscules could be found during a short period (2-3 wk) of the year and Allen et al. (1989) reported that even the nonmycotrophic annual YSalsola kali formed arbuscules for short intervals (2-3 d) as seedlings. Alternatively, Miller et al. (1983) suggested that limited mycorrhizal fungal activity of the perennial Atriplex con fertifolia could be found, but only when the VA mycorrhizal fungi were associated with a neighboring mycorrhizal grass. One proposed hypothesis was that the annual members of the Chenopodiaceae have lost their mycorrhizal associations as a condition of their colonizing habit (Malloch et al. 1980). The hypothesis that perennial Chenopodiaceae may be weakly mycorrhizal implies that the plant does not contribute significantly to fungal growth (Miller et al. 1983). VA mycorrhizal fungi are obligately dependent upon a host plant for carbon, that is, the fungus cannot gain sufficient carbon from residual organic matter to reproduce (e.g., Hepper 1983, Allen and Allen 1990). Although we have observed all internal organs of the VA mycorrhiza in both the annual chenopodiacean

Environmental Factors Influencing Gardner Saltbush Seed Dormancy Alleviation

Pregermination treatments applied to seed of Gardner saltbush, [ALriplexgar&cri(Moq.) D. Dietr.] were evahtated for alleviation of seed dormancy. Treatments selected simulated conditions the seed might be exposed to in its natural environment, including dry afterripening, scarification, leaching, and cold stratification. Germination response to individual treatments was equal to or higher than nontreated seed. Germination percentage of afterripened seed was increased from 17% for nontreated filled seed to an average of 86% of filled seed by the combined treatments of scarification, leaching, and 4-week stratification. This combination of treatments allowed optimum germination. Response to treatments provided evidence as to the type of dormancy in Gardner saltbush seeds. The levels of germination response to specific treatments appears to be an adaptation to ensure a temporal dispersal of dormancy release and seedling emergence. Pregermination treatments used in this study were relatively easy to apply to the seeds and stimulated germination without potentially damaging the embryo. Thus, they would be useful in revegetation by direct seeding efforts. Gardner saltbush [Atriplexgurdneri (Moq.) D. Dietr.] is a lowgrowing perennial half-shrub, 20 to 50 cm tall, which occurs in cold desert regions of Montana and Wyoming. It is particularly adapted to saline, alkaline, and clayey soil conditions, extreme temperatures, high winds, and aridity (Stubbendieck et al. 1981). It is a

Seed Pretreatments and Their Effects on Field Establishment of Spring-Seeded Gardner Saltbush

Seed Pretreatments and Their Effects on Field Establishment of Spring-Seeded Gardner Saltbush

Formation of Vesicular-Arbuscular Mycorrhizae in Atriplex Gardneri (Chenopodiaceae): Seasonal Response in a Cold Desert

Arbuscules and total VA mycorrhizal colonization in Atriplex gardneri were observed during the spring and summer of 1982. Arbuscules were observed in April (25% of secondary and tertiary root length intercepts) but were not found in June. Total VA mycorrhizal colonization was 78% of fine root length intercepts in April, 28% in June, and 3% by July. The phenology of the fungus was correlated with that of the plant; rainfall and temperature dictated periods of active growth, nutrient uptake, and senescence in the symbionts.

TheAspergillus OchraceusGroup: Two New Species from Western Soils and a Synoptic Key

Two new species in the Aspergillus ochraceus group are described and compared to related taxa. Aspergillus bridgeri, from soils collected in a native community dominated by Atriplex gardneri in Wyoming, somewhat resembles A. elegans and A. lanosus, but differs in cultural and morphological details. Aspergillus campestris, from a native prairie in northern North Dakota, resembles A. dimorphicus in having metulae that are up to 35-45 im long, but is a more restricted form with yellow conidial heads, taller conidiophores, occasionally septate metulae, and ellipsoidal conidia. A synoptic key is presented as an aid to identification of species in the A. ochraceus group-an assemblage which has increased considerably since 1965 and currently embraces 15 species. Brief descriptions of the species accompany the key along with distributional and ecological analyses prepared from species lists in more than 130 published surveys.

Growth Response of Two Saltbush Species to Nitrate, Ammonium, and Urea Nitrogen Added to Processed Oil Shale

Nitrate nitrogen promoted good growth of cuneate saltbush (Atriplex cuneatu) and gardner saltbush (A. garz Morris and Gidden 1963). Having been mined from underground and retorted at high temperature, processed oil shale is biologically sterile and thus microbial nitrogen transformations would not occur. An experiment was conducted to determine how two salt tolerant subshrubs from northeastern Utah, cuneate saltbush (Atriplex cuneata) and gardner saltbush (Atriplex gardneri), would respond to nitrate, ammonium, and urea nitrogen added to processed oil shale.

Some occurrences of vesicular–arbuscular mycorrhiza in natural and disturbed ecosystems of the Red Desert

Studies have been initiated on the occurrence of vesicular–arbuscular mycorrhiza (VAM) in plant communities of revegetated mine spoils and undisturbed areas of the Red Desert of Wyoming. It was found that the majority of plants in undisturbed environments in this area are mycorrhizal. On disturbed sites, no mycorrhiza were encountered. Of interest for both the undisturbed and disturbed communities was the predominance of plants belonging to the family Chenopodiaceae. The major difference between the plant species encountered in each community is associated with their reproductive strategy, as well as whether the plants possessed VAM. The major species encountered on undisturbed sites are Atriplex gardneri, At. confertifolia, Ceratoides lanata, Grayia spinosa, Kochia americana, and Sarcobatus vermiculatus, all possessing mycorrhiza. Halogeton glomeratus predominated in disturbed sites and did not possess VAM. The role of VAM in both succession and reproductive strategies of plants is also discussed.