Big Sagebrush Seedlings Research Articles

Survivability of Wyoming Big Sagebrush Transplants

On the Ground • Wyoming big sagebrush is a dominant shrub species on millions of acres of rangelands throughout the Intermountain West and plays a critical role in the health and diversity of many wildlife species. • Restoration practices to re-establish Wyoming big sagebrush on degraded habitats have largely been met with submarginal success, yet the need to restore or rehabilitate Wyoming big sagebrush has become increasingly important due to extensive losses of big sagebrush habitats, fragmentation, and sensitive sagebrush obligate species. • Lack of success from seeding rangelands either by ground application or aerially has prompted some resource managers to look more closely at transplantng methodologies. Transplanting of Wyoming big sagebrush is largely done using cone-size containers or bare-stock plants and is recommended to be conducted in spring. This study was initiated in 2012 to test fall versus spring transplanting. • Fall transplanting success averaged 65% with a range of 41% to 82%, while spring transplant success averaged 41% with a range of 13% to 65%. • The cold desert of the Great Basin receives the majority of its precipitation during winter months, therefore providing a more reliable source of available precipitation for newly transplanted Wyoming big sagebrush seedlings. A significant part of increasing big sagebrush transplanting success is the combination of increased container size and moving the timing of transplanting from spring to fall due to an increase in favorable and reliable precipitation.

Do Container Volume, Site Preparation, and Field Fertilization Affect Restoration Potential of Wyoming Big Sagebrush?

Land management practices, invasive species expansion, and changes in the fire regime greatly impact the distribution of native plants in natural areas. Wyoming big sagebrush (Artemisia tridentata ssp. wyomingensis), a keystone species in the Great Basin, has seen a 50% reduction in its distribution. For many dryland species, reestablishment efforts have focused on direct seeding but achieved only minor success due to irregular seed germination and poor survival. We investigated the effects of container volume and fertilization on the performance of nursery-grown Wyoming big sagebrush seedlings following outplanting. Additionally, to evaluate the impact of site preparation, one-year-old seedlings were outplanted into tilled and untilled field conditions. Initial seedling size increased with container volume; larger seedlings exhibited significantly higher root collar diameter (RCD) growth than smaller seedlings. As container volume increased from 108 to 251 and 336 cm3, seedling survival on the tilled plot increased from 28 to 44 and 43%, respectively, whereas no influence was observed on the untilled plot (57 to 61, and 60%, respectively). Fertilization reduced seedling survival on tilled (by 25%) and untilled (by 14%) plots. Fertilizer increased RCD growth on the untilled plot but final nutrient status was unaffected. Thus, container volume may influence seedling morphology and optimize establishment, while field fertilization, especially during spring outplanting when planting sites have low moisture availability, may hinder first-year survival.

Natural Regeneration Processes in Big Sagebrush (Artemisia tridentata)

Big sagebrush, Artemisia tridentata Nuttall (Asteraceae), is the dominant plant species of large portions of semiarid western North America. However, much of historical big sagebrush vegetation has been removed or modified. Thus, regeneration is recognized as an important component for land management. Limited knowledge about key regeneration processes, however, represents an obstacle to identifying successful management practices and to gaining greater insight into the consequences of increasing disturbance frequency and global change. Therefore, our objective is to synthesize knowledge about natural big sagebrush regeneration. We identified and characterized the controls of big sagebrush seed production, germination, and establishment. The largest knowledge gaps and associated research needs include quiescence and dormancy of embryos and seedlings; variation in seed production and germination percentages; wet-thermal time model of germination; responses to frost events (including freezing/thawing of soils), CO2 concentration, and nutrients in combination with water availability; suitability of microsite vs. site conditions; competitive ability as well as seedling growth responses; and differences among subspecies and ecoregions. Potential impacts of climate change on big sagebrush regeneration could include that temperature increases may not have a large direct influence on regeneration due to the broad temperature optimum for regeneration, whereas indirect effects could include selection for populations with less stringent seed dormancy. Drier conditions will have direct negative effects on germination and seedling survival and could also lead to lighter seeds, which lowers germination success further. The short seed dispersal distance of big sagebrush may limit its tracking of suitable climate; whereas, the low competitive ability of big sagebrush seedlings may limit successful competition with species that track climate. An improved understanding of the ecology of big sagebrush regeneration should benefit resource management activities and increase the ability of land managers to anticipate global change impacts.

Insights into big sagebrush seedling storage practices

Big sagebrush (Artemisia tridentata Nutt. (Asteraceae)) is an essential component of shrub-steppe ecosystems in the Great Basin of the US, where degradation due to al- tered fire regimes, invasive species, and land use changes have led to increased in- terest in the production of high-quality big sagebrush seedlings for conservation and restoration projects. Seedling storage is an important consideration in the production of high-quality planting stock, yet little is known about optimal storage conditions for this species. Our survey of nurseries in western US found that only 13% of those that grow big sagebrush in containers use cooler or freezer storage to maintain seedling quality. Of those nurseries, 80% rely on cooler storage. We tested cooler (2 to 4 °C) and freezer (0 to -2 °C) storage of big sagebrush in late spring and found that 2 mo of freezer storage reduced survival after transplanting from 96 to 78%, but seedling growth was unaffected. This suggests that seedlings may be more suscepti- ble to freezer conditions because of reduced cold hardiness in spring, but that either storage temperature maintains seedling vigor. Future work is needed on big sage- brush to determine the appropriate hardening regime and lifting dates for freezer storage. Overton EC, Pinto JR, Davis AS. 2013. Insights into big sagebrush seedling storage practices. Native Plants Journal 14(3):225-230.

Insights into big sagebrush seedling storage practices

Big sagebrush (<i>Artemisia tridentata</i> Nutt. [Asteraceae]) is an essential component of shrub-steppe ecosystems in the Great Basin of the US, where degradation due to altered fire regimes, invasive species, and land use changes have led to increased interest in the production of high-quality big sagebrush seedlings for conservation and restoration projects. Seedling storage is an important consideration in the production of high-quality planting stock, yet little is known about optimal storage conditions for this species. Our survey of nurseries in western US found that only 13% of those that grow big sagebrush in containers use cooler or freezer storage to maintain seedling quality. Of those nurseries, 80% rely on cooler storage. We tested cooler (2 to 4 °C) and freezer (0 to –2 °C) storage of big sagebrush in late spring and found that 2 mo of freezer storage reduced survival after transplanting from 96 to 78%, but seedling growth was unaffected. This suggests that seedlings may be more susceptible to freezer conditions because of reduced cold hardiness in spring, but that either storage temperature maintains seedling vigor. Future work is needed on big sagebrush to determine the appropriate hardening regime and lifting dates for freezer storage.

Cold Hardiness in Wyoming Big Sagebrush Seedlings: Implications for Nursery Production and Outplanting

Advisory No. 2. Appalachian Regional Reforestation Initiative, U.S. Office of Surface Mining. Diskin, M., K.C. Steiner and F.V. Hebard. 2006. Recovery of American chestnut characteristics following hybridization and backcross breeding to restore blight-ravaged Castanea dentata. Forest Ecology and Management 223:439–447. Hebard, F.V. 2001. Backcross breeding program produces blight-resistant American chestnuts. Ecological Restoration 19:252–254. Jacobs, D.F. 2007. Toward development of silvical strategies for forest restoration of American chestnut (Castanea dentata) using blight-resistant hybrids. Biological Conservation 137:497–506. McCarthy, B.C., J.M. Bauman and C.H. Keiffer. 2008. Mine land reclamation strategies for the restoration of American chestnut. Ecological Restoration 26:292–294. Sayler, K. L. 2008. Land Cover Trends: Central Appalachians. U.S. Department of the Interior, U.S. Geological Survey. landcovertrends.usgs.gov/east/eco69Report.html Wickam, J.D., K. Riitters, T. Wade, M. Coan and C. Homer. 2007. The effect of Appalachian mountaintop mining on interior forest. Landscape Ecology 22:179–187.

Cold Hardiness in Wyoming Big Sagebrush Seedlings: Implications for Nursery Production and Outplanting

Cold Hardiness in Wyoming Big Sagebrush Seedlings: Implications for Nursery Production and Outplanting

English

In the late 1980s, two coal gasification concepts were tested at a 15- acre site in the Hanna Basin of south-central Wyoming. Both tests were conducted in the Hanna No. 1 Coal Seam, which is about 30 feet thick and 365 feet below surface at this site. Approximately 4500 tons and 11,300 tons of coal were burned in the two tests, respectively. The Land Quality Division (LQD) of the Wyoming Department of Environmental Quality (WDEQ) issued Research and Development License No. 15 (RD15) to Stearns Catalytic Corporation (now Washington Group International, Inc.) for the tests. Per the license requirements, ground water restoration and surface reclamation were necessary after the tests. Because of the efficiency of the burns and the effectiveness of venting and flushing the burn cavities after each test, ground water restoration was completed in 1989. Once ground water restoration was deemed complete, the 30+ wells were abandoned and surface reclamation began. The reported seed mix included Wheatgrass (western, thickspike, and slender), Indian Ricegrass, Fourwing Saltbush, and Big Sagebrush. In addition, Big Sagebrush seedlings were also planted. Surface reclamation was completed in 1993, with limited repair work (primarily weed control) in subsequent years. The LQD released the reclamation bond and terminated the license in late 2005. Even though this site was tiny in comparison with most in situ noncoal mines and traditional coal mines, it provides a microcosm of reclamation issues, including: drought impacts; selection of areas for evaluation of reclaimed vegetation; and comparison of species planted with species expressed. It also provides information specific to reclamation issues at in situ mining projects, such as extent of ground water contamination, measurement of revegetation success at sites with multiple, relatively small areas of disturbance, and soil sampling for water treatment impacts. The site was one of the first evaluated for bond release under Category 5 of the LQD Coal Rules.

Long-Term Survival of Direct Seeded Wyoming Big Sagebrush Seedlings on a Reclaimed Mine Site

Reestablishment of Wyoming big sagebrush (Artemisia tridentata Nutt. ssp. wyomingensis) on mined lands has become a requirement in recent years in Wyoming. Its reestablishment by direct seeding has been greatly improved through a better understanding of the role of topsoil management, mulching, seed quality, and competition. However, long-term survival of reestablished sagebrush seedlings on mined sites has only rarely been evaluated because of the short-term nature of previous studies. Sagebrush seedling survival was assessed after eight years on a mine site in northeastern Wyoming near Gillette on research initiated in 1992 to assess the effect of several cultural practices on sagebrush establishment. Wyoming big sagebrush survival was found to average 59% after eight years. Interestingly, the greatest survival occurred on the treatments seeded at the higher rates of grass (competition). Sagebrush survival was 46, 58, and 72% for the grass seeding rates of 0, 16, and 32kg pure live seed (PLS) ha -1 , respectively. This resulted in a density of 2.5, 2.4, and 2.8 shrubs m -2 for the respective grass seeding rates. These findings in some ways contradict the belief that herbaceous competition restricts Wyoming big sagebrush establishment; however, we believe the higher grass seeding rates actually resulted in the grass plants "sheltering" the seedlings from excessive foraging by wildlife. Browse estimates showed that 40, 27, and 32% of the sagebrush seedlings had been browsed in 2001 on the 0, 16, and 32kg PLS ha -1 grass seeding rates, respectively. The average survival (59%) should enable reclamationists to meet the Wyoming shrub density requirement of 1m -2 during the last two years of the 10-year bonding period if initial establishment density is S 2 shrubs m -2 .

Arbuscular Mycorrhizae and Water Stress Tolerance of Wyoming Big Sagebrush Seedlings

AbstractAlthough Wyoming big sagebrush (Artemisia tridentata Nutt. ssp. wyomingensis Beetle and Young) is widespread in the western USA, reestablishment of this native shrub on disturbed lands by direct seeding is problematic. A number of theories have been proposed to explain this difficulty. Included are the hypotheses that seedlings are unable to obtain adequate moisture and are handicapped by reduced levels of mycorrhizae in perturbed soils. We conducted a greenhouse study to examine the influence of vesicular arbuscular mycorrhizae (VAM) and seedling age on soil moisture stress tolerance of Wyoming big sagebrush seedlings. Results demonstrated greater survival of mycorrhizal seedlings than nonmycorrhizal seedlings as soil dried down past soil water potential values of ‐2.5 MPa to as dry as −3.8 MPa. For all different aged seedlings tested (30, 45, 60, 90, 120, 150 d), the degree of soil dryness resulting in death of mycorrhizal seedlings was significantly greater (P &lt; 0.01) than that causing death of nonmycorrhizal seedlings. Analysis of variance indicated a significant interaction of seedling age and mycorrhizae on moisture stress tolerance. Experimental data suggest that as sagebrush seedlings age, the beneficial influence of arbuscular mycorrhizae on soil water stress tolerance increases.

Soil Surface Characteristics and Emergence of Big Sagebrush Seedlings

The emergence of big sagebrush (Artemtricr frkfeufotcr) seedlings from 5 gardens where both the seed source and the soils were reciprocated was investigated over a g-year period in western Nevada. The sites where the study was conducted were located at the arid extremes for mountain (A. rrGfenturu subsp. vareyuna) and basin big sagebrush (A. tridentata subsp. tridentata) in the transSierra Nevada area. Soils, sites, and seed sources differed significantly (FO.01) in seedling emergence. The driest site, where it was difficult to obtain seedling emergence even on a year of above average precipitation, had a soil surface that was very conducive to the germination of seeds of big sagebrush when the seedbed was moved to garden locations with greater environmental potential. Seedbed quality differed markedly among sites with soil derived from decomposing granite versus metavolcanic sources. Big sagebrush seeds were buried in soils derived from granite through a winnowing action. Seeds from a non-granltlc soil site were also adapted, apparently through size and shape, to this winnowing self-burial. The dominant microenvironmental factors contributing to seedling emergence tended to be site and seed source specific. Microtopography in the fall, when seeds were dispersed, and seasonal precipitation were dominant factors controlling the emergence of big sagebrush seedlings.

Dispersal and Germination of Big Sagebrush (Artemisia tridentata) Seeds

The purpose of this study was to investigate seed dispersal and germination of seeds in the soil as factors in establishment of big sagebrush seedlings. Seed dispersal began at seed maturity in December. Under the shrub canopy the dispersal of seeds was greater to the east. Between shrubs the dispersal of seeds tended to be uniform. For 6 months of each year there were no detectable germinable seeds in the litter and surface soil at the sites sampled. Germinable seeds in the soil increased rapidly during seed dispersal but were not detected by June of the next season. Enrichment of bioassay samples with GA3or KNO3did not enhance emergence of big sagebrush seedlings. Big sagebrush seedlings were found at very low densities in areas previously burned in wildfires. This suggests the presence of viable big sagebrush seeds in the soil at a very low density.

Mule Deer-Induced Mortality of Mountain Big Sagebrush

AbStMCt A fence line contrast was provided by a deer fence that bisected a mountain big sagebrush (Artend& tridkntata sap. vaseyana) community. The ~pbruab community was located on an exposed, west-fadng slope that was generally swept free of snow during the severe winters of 1982-83 and 1983-84. On the freeway side of the fence, the site was essentially free of browsing animals, while above the fence, the shrubs were exposed to concentrations of mule deer (Odocoikus hemioms). Considerable big sagebrush mortality was evident after the 2 succeusive winters of heavy snowfall. Big sagebrush mortality and partial dieback of portions of the canopy were significantly (PCO.05) higher in the portion of the community exposed to browsing. Herbaceous species composition also differed between the protected and browsed areas with a higher portion of annual species found in the browsed community. A large number of big sagebrush seedlings germinated in 1984, but failed to establish by 1986. Excessive use of native plants by native large herbivores can have lasting effects on plant communitien.

Evaluation of Fall Burning on Bighorn Sheep Winter Range

Evaluation of Fall Burning on Bighorn Sheep Winter Range