Western Juniper Field Guide: Asking the Right Questions to Select Appropriate Management Actions

Strong evidence indicates that western juniper has significantly expanded its range since the late 1800s by encroaching into landscapes once dominated by shrubs and herbaceous vegetation (fig. 1). Woodland expansion affects soil resources, plant community structure and composition, water, nutrient and fire cycles, forage production, wildlife habitat, and biodiversity. Goals of juniper management include an attempt to restore ecosystem function and a more balanced plant community that includes shrubs, grasses, and forbs, and to increase ecosystem resilience to disturbances. Developing a management strategy can be a difficult task due to uncertainty about how vegetation, soils, hydrologic function, and wildlife will respond to treatments. When developing a management strategy, the first and possibly most important step towards success is asking the right questions. Identifying the attributes of the area to be treated and selecting the right treatments to be applied are of utmost importance. One must ask questions addressing the kind of site (that is, potential natural vegetation, soils, etc.), the current state of the site (that is, successional, hydrologic, etc.), what components need to be restored, how the management unit fits in with the overall landscape mosaic, and the long-term goals and objectives for the area or region. Keep in mind sagebrush-steppe vegetation is dynamic and management strategies must take into account multi-decade time frames. This guide provides a set of tools that will help field biologists, land managers, and private landowners conduct rapid qualitative field assessments that address the kind of site and its current state. These tools include a list of questions to be addressed and a series of photographs, keys, tables, and figures to help evaluate a site. Conducting this assessment will help prioritize sites to be treated, select the best treatment, and predict outcomes. Success of a juniper management program may be greatly enhanced if an interdisciplinary team of local managers and resource specialists, who are experienced with vegetation, fuels, soils, hydrology, wildlife, and economic and sociological aspects of the local resource, use this guide to aid their decision-making

Rhizosphere-mediated effects of the invasive grass Bromus tectorum L. and native Elymus elymoides on nitrogen cycling in Great Basin Desert soils

Background and aims: There is evidence that the invasive grass Bromus tectorum can affect soil nitrogen (N) cycling, possibly leading to a positive plant-soil feedback. Rhizosphere priming of N mineralization could provide a mechanistic explanation for such a feedback. Methods: We conducted a greenhouse study to isolate rhizosphere effects on N cycling by the invasive annual grass, Bromus tectorum L., and the native perennial grass, Elymus elymoides (Raf.) Swezey, in invaded and uninvaded soils. We compared the rhizosphere priming effect (RPE) on N mineralization by species and the distribution of N in various pools by planting treatment and soil type. Results: B. tectorum had a negative RPE (−23 and −22 % in invaded and uninvaded soils, respectively), while E. elymoides had no significant RPE. B. tectorum was more competitive over E. elymoides in invaded compared to uninvaded soil. Conclusions: B. tectorum had a negative effect on soil N availability via root-mediated processes, even though its growth and competitiveness increased in invaded soils. Positive plant-soil feedback effects of B. tectorum may be mediated by aboveground inputs rather than belowground and/or depend on site-specific conditions

Author Correction: Drivers of seedling establishment success in dryland restoration efforts

1 Pág. Correción errata.In the version of this Article originally published, the surname of author Tina Parkhurst was incorrectly written as Schroeder. This has now been corrected.Peer reviewe

Animal performance and diet quality as influenced by burning on tallgrass prairie

Burning on good to excellent condition tallgrass prairie in central Oklahoma yielded results which visually appeared much greater than would be expected from previous burning research. Therefore, a study was designed to quantify the effect of burning on plant and livestock responses. During 1984-1986, average daily gains of stocker cattle were monitored from late May to mid-October in replicated burned and unburned pastures. Stocking rates varied from 0.8 to 1.5 ha per animal depending on initial animal weights. Fistulated cattle were used to monitor diet quality on the pastures. Standing crops were measured at the end of the growing season (early October) in exclosures, and at the end of the grazing period (late October) in the pastures. Animal performance was improved by burning during the early part of the grazing season, and over the season animal production per ha averaged 11.2 kg higher on burned compared to unburned pastures. Dietary crude protein tended to be higher on unburned compared to burned pastures, but the opposite was true for in vitro organic matter digestibility. Standing crop remaining after the grazing period averaged 4,304 and 2,539 kg/ha for burned and unburned pastures, respectively. Standing crop was 57% higher in burned compared to unburned exclosures. Burning caused a shift in species composition to favor tallgrass species and lower production of weedy forbs in both exclosures and grazed pastures.This material was digitized as part of a cooperative project between the Society for Range Management and the University of Arizona Libraries.The Journal of Range Management archives are made available by the Society for Range Management and the University of Arizona Libraries. Contact [email protected] for further information.Migrated from OJS platform August 202

Growth and gas exchange of Andropogon gerardii as influenced by burning

Late spring burning response of the dominant big bluestem (Andropogon gerardii) was studied on a tallgrass site in central Oklahoma (USA) during a dry (1984) and a wet (1985) year. During active growth (May and June) when temperatures were not limiting, photosynthesis (PS) was higher for burned (25-27 micromoles-2-1) relative to unburned plants (20-25 micromoles m-2 s-1); but during summer drought, PS declined to <10 micromoles m-2 s-1 and treatment rank reversed. However, the 2 treatments had similar transpiration per unit leaf area, and burned plots had much higher peak big bluestem leaf area indices (6.4 in 1984 and 4.5 in 1985) than unburned plots (2.0 both years). Apparently higher transpirational demand in burned plots lowered soil moisture, thereby increasing late season moisture stress and lowering PS relative to unburned plots. Burning resulted in a doubling of big bluestem tiller numbers (997-1,034 and 498-600 tillers m-2 for burned and unburned plots, respectively). Peak aboveground biomass of big bluestem was about 3 times higher on burned relative to unburned prairie during both years. During both years burned vs. unburned big bluestem had higher peak values of % leaf nitrogen (N) and more total leaf N (%N* leaf mass). Thus, burning big bluestem increased leaf area during the active growth period and stimulated PS, resulting in higher carbon uptake of burned relative to unburned plants.This material was digitized as part of a cooperative project between the Society for Range Management and the University of Arizona Libraries.The Journal of Range Management archives are made available by the Society for Range Management and the University of Arizona Libraries. Contact [email protected] for further information.Migrated from OJS platform August 202

Gas exchange and water relations of Lemmon's willow and Nebraska sedge

There is considerable interest in riparian zones in the western United States, yet little information is available on the autecology of plant species that dominate these areas. We measured gas exchange and xylem water potential of Nebraska sedge (Carex nebrascensis Dewey) and Lemmon's willow (Salix lemonii Bebb) growing in a streamside location in the northern Sierra Nevada over a 2 year period. Standing biomass of both species and leaf area index of Lemmon's willow was also determined. Rooting activity of Nebraska sedge was measured the second year of the study. Measurements were taken during 1988 and 1989 with growing season precipitation 46% and 110% of average, respectively. Photosynthesis was remarkably similar for the 2 species (10.9 and 11.1 micromoles m-2 second-1 for Nebraska sedge and Lemmon's willow, respectively) when averaged over all dates for the 2 years. However, the 2 species exhibited different seasonal and yearly patterns of photosynthesis. Nebraska sedge maintained higher rates of photosynthesis during the early portion of the growing season and Lemmon's willow had higher photosynthesis during mid to late summer. Mean seasonal rates of willow photosynthesis were higher than those of the sedge during the drought year, and the opposite was true during the average year. Yearly average photosynthesis varied more for the sedge than for the willow. However, mean seasonal photosynthesis rates for each species were higher in an average year compared to a drought year. Nebraska sedge almost always had more negative values of xylem water potential than Lemmon's willow (overall average was -2.6 MPa and -1.25 MPa for Nebraska sedge and Lemmon's willow, respectively). Trends in transpiration and conductance were similar among species, except that Nebraska sedge maintained higher rates than Lemmon's willow during the spring of 1989. Willow biomass was similar among years, but willow leaf area index and sedge biomass were slightly greater in the wet year (1989) compared to the dry year. Contrasting growth forms and morphology of the 2 species may help explain differences in gas exchange and xylem water potential. The ability of willows to tap groundwater and the concentration of sedge roots in the upper soil profile probably accounts for the differential response to drought.The Journal of Range Management archives are made available by the Society for Range Management and the University of Arizona Libraries. Contact [email protected] for further information.Migrated from OJS platform August 202

The grass seedling: When is it established?

Adventitious roots of sufficient length and diameter must develop to assure that the photosynthetic surfaces receive sufficient water and nutrients before grass seedlings can be considered established. We evaluated development of crested wheatgrass [Agropyron desertorum (Fisch. ex Link) Schult.] and blue grama [Bouteloua gracilis (H.B.K.) Lag.] seedlings in the field to decide when they were established. Blue grams and crested wheatgrass seedlings, under the environmental conditions of this study, were considered established 21 days after emergence. At this time, crested wheatgrass seedlings had 4 leaves, 2 adventitious roots penetrating to a depth of at least 80 mm into the soil, and 1 tiller per plant. Blue grama seedlings had about 6 leaves, 2 adventitious roots penetrating to a depth of at least 100 mm into the soil, and 2 tillers per plant. Most seedlings that reached this stage by the end of the first growing season overwintered and survived the following growing season and provided adequate stands for both species.This material was digitized as part of a cooperative project between the Society for Range Management and the University of Arizona Libraries.The Journal of Range Management archives are made available by the Society for Range Management and the University of Arizona Libraries. Contact [email protected] for further information.Migrated from OJS platform August 202

Willow planting success as influenced by site factors and cattle grazing in northeastern California

In recent years there has been an increasing emphasis on reestablishment of woody vegetation in degraded riparian zones. In this study we evaluated the influence of grazing and selected site factors on survival and leader growth of planted Geyer willow (Salix geyeriana Anderss.) cuttings. Three grazing treatments (early summer, late summer, and non-use) were evaluated on each of 3 streams in broad, low-gradient meadows with silt loam soils in the northern Sierra Nevada. The streams were perennial with terraces often 1.0 to 1.5 m above streambottom. Unrooted Geyer willow cuttings were planted to 30-cm soil depth in early May 1987 at 3 streamchannel locations (streambottom, streambank, and stream terrace) within each of the grazing treatments. Survival, associated community type, and cover class were determined for 2,700 plantings. Leader length and grazing intensity were measured for 694 surviving cuttings in 1988. Percent soil moisture and water table depth were determined for a subset of the willow cuttings. There was no significant (P>0.05) effect of grazing treatment on either willow survival or growth despite 3.5 to 5 times more defoliation use of the willow cuttings in the grazed pastures. Streamchannel location did significantly (P lesser than or equl to 0.05) affect willow survival (streambottom = 83%, streambank = 34%, and stream terrace = 3%) but not individual plant leader length. Survival of willow cuttings for Carex nebrascensis/Jancas nevadensis, bareground, Des- champsia caespitosa/Carex nebrascensis, and Artemisia sp. dominated sites was 76, 60, 44, and 2%, respectively. However, leader length was significantly (P lesser than or equal to 0.05) greater for bareground sites than for sites supporting vegetation. Cover class was not a good indicator of survival, but as might be expected from the results on the bareground sites, leader length for the 0-5% class was 1.8 times the length of the next class. There was a clear relationship between water table depth, soil moisture, and willow planting survival but not between moisture measurements and leader length. Once the water table has declined to the point that Artemisia sp. can survive on a site, the chances of successfully replanting willows are minimal. However, even during the drought years of this study (<50% of average annual precipitation) a survival rate of 60% or greater was achieved by planting into Carex nebrascensis communities or bareground in the streamchannel.This material was digitized as part of a cooperative project between the Society for Range Management and the University of Arizona Libraries.The Journal of Range Management archives are made available by the Society for Range Management and the University of Arizona Libraries. Contact [email protected] for further information.Migrated from OJS platform August 202

Grass Seedling Demography and Sagebrush Steppe Restoration

Seeding is a key management tool for arid rangeland. In these systems, however, seeded species often fail to establish. A recent study in Wyoming big sagebrush steppe suggested that over 90% of seeded native grass individuals die before seedlings emerged. This current study examines the timing and rate of seed germination, seedling emergence, and seedling death related to this demographic bottleneck. We seeded monocultures of two native perennial bunchgrasses, Pseudoroegenaria spicata (Pursh) Á. Löve and Elymus elymoides (Raf.) Swezey, and one introduced bunchgrass, Agropyron desertorum (Fisch. ex Link) Schult., in 2007, 2008, and 2009 and tracked sown seed and seedling fate. Across the study years and species we found that germination was rapid and high, with species obtaining 50% germination by December, less than 2 mo after planting. Emergence of germinated seed did not occur until late February for A. desertorum and March for the two native grasses. In 2007 the majority of emergence and death was constrained to several weeks, whereas in 2008 and 2009 emergence and death was distributed across several months. The timing of seedling emergence did not influence survival probability or midday plant water potential (probability of exceedance 0.98). The early germination of grasses following fall seeding, and the long 2- to 3-mo period that germinated grass seed remain in the soil before emerging, support the hypothesis that seedling recruitment might be limited largely by ecological processes and conditions during winter or early spring (such as soil freeze-thaw events, seed pathogens, or physical crusts). Delaying seeding to early winter or spring and other management tools that mitigate these factors driving this bottleneck might greatly improve restoration outcomes in these systems./Las resiembras son una herramienta clave de manejo para pastizales áridos. En estos sistemas, sin embargo, las especies sembradas a menudo no se establecen. En un estudio reciente en un pastizal de Artemisia en Wyoming se sugiere que más del 90% de los individuos sembrados de pastos nativos mueren antes que la plántula germine. Este estudio examina la época y tasa de germinación de las semillas, la aparición de la plántula, y la muerte de plántula relacionadas con el cuello de botella demográfico. Se sembraron monocultivos de dos especies nativas de pastos amacollados, Pseudoroegenaria spicata (Pursh) Á. Löve y Elymus elymoides (Raf.) Swezey, y también un pasto amacollado introducido, Agropyron desertorum (Fisch. ex Link) Schult., durante 2007, 2008, y 2009 y se le dio seguimiento a las semillas sembradas así como el destino de las plántulas. Através de los años de estudio y especies se vio que la germinación fue rápida y alta, con la obtención de la germinación del 50% en diciembre, menos de 2 meses después de la siembra de especies. La aparición de semillas germinadas no ocurrió hasta finales de febrero para A. desertorum y en marzo para las dos especies de pastos nativos. En 2007 la mayoría de aparición y muerte estaba limitada a varias semanas mientras que en 2008 y 2009 el surgimiento y la muerte se distribuyeron a través de varios meses. El tiempo de aparición de las plántulas no influyó en la probabilidad de la supervivencia o al potencial de agua de laplanta al mediodía o (probabilidad de superación 0.98). La germinación temprana de gramíneas después de que cae la semilla y el periodo tardo dedos a tres meses la semilla germinada permanece en el suelo antes de emerger y apoya la hipótesis que el reclutamiento de plántulas puede estar altamente limitado por el proceso ecológico y las condiciones durante el invierno o el inicio de la primavera tales (como la descongelación del suelo, los patógenos de la semilla, o las costras físicas). Retrasando la siembra a principios del invierno o primavera y usando otras herramientas de manejo que mitiguen los factores que impulsan este cuello debotella se puede mejorar considerablemente los resultados de la restauración en estos sistemasThe Rangeland Ecology & Management archives are made available by the Society for Range Management and the University of Arizona Libraries. Contact [email protected] for further information.Migrated from OJS platform August 202

Incorporating Plant Mortality and Recruitment Into Rangeland Management and Assessment

Rangeland management is largely focused on managing vegetation change. Objectives may include managing against change if the desired vegetation is in place, or attempting to create a shift in vegetation if the desired plant community is not present. There is a rich body of research documenting influences of disturbance and management on rangeland vegetation. However, in many cases the information is largely observational and does not identify mechanisms driving change. We propose using the regeneration niche concept to more effectively predict when vegetation change is possible and to suggest successional direction. Simply stated, as plants die and leave gaps in the community, recruitment of new individuals will dictate successional direction. Recruitment requires that propagules are present, that the propagules find safe sites in which to establish, and that the seedlings and young plants are able to compete with existing vegetation and survive. In many rangeland communities, perennial bunchgrasses are a key to stability and invasion resistance. Existing literature shows that most rangeland bunchgrasses have average life spans of 10 yr or less, so periodic recruitment is necessary to maintain communities in which they are a major component. Disturbance can influence plant population dynamics, and we suggest classifying disturbances based on how they influence mortality and recruitment. We also suggest that more emphasis be placed on the concept of critical transitions and less on the degree of disturbance per se. In other words, a small disturbance at the wrong point in community composition (low plant density and high gap size for example) can cause a transition, whereas major disturbance in a high condition community may yield little risk of transition. We suggest that a focus on mortality and recruitment will provide a mechanistic approach for predicting vegetation change and making management decisions. We refer to this approach as recruitment-based management. © 2014 Society for Range ManagementThe Rangeland Ecology & Management archives are made available by the Society for Range Management and the University of Arizona Libraries. Contact [email protected] for further information