Now showing items 1-20 of 10404

    • Rangeland Ecology & Management Table of Contents Volume 72, Number 6 (2019)

      Society for Range Management (Elsevier Inc., 2019-11)
    • Rangeland Ecology & Management Table of Contents Volume 72, Number 5 (2019)

      Society for Range Management (Elsevier Inc., 2019-09)
    • Rangeland Ecology & Management Table of Contents Volume 72, Number 4 (2019)

      Society for Range Management (Elsevier Inc., 2019-07)
    • Rangeland Ecology & Management Table of Contents Volume 72, Number 3 (2019)

      Society for Range Management (Elsevier Inc., 2019-05)
    • Rangeland Ecology & Management Table of Contents Volume 72, Number 1 (2019)

      Society for Range Management (Elsevier Inc., 2019-01)
    • Rangeland Ecology & Management Table of Contents Volume 72, Number 2 (2019)

      Society for Range Management (Elsevier Inc., 2019-03)
    • Rangeland Ecology & Management Editorial Board Volume 72, Number 6 (2019)

      Society for Range Management (Elsevier Inc., 2019-11)
    • Rangeland Ecology & Management Editorial Board Volume 72, Number 5 (2019)

      Society for Range Management (Elsevier Inc., 2019-09)
    • Rangeland Ecology & Management Editorial Board Volume 72, Number 4 (2019)

      Society for Range Management (Elsevier Inc., 2019-07)
    • Rangeland Ecology & Management Editorial Board Volume 72, Number 3 (2019)

      Society for Range Management (Elsevier Inc., 2019-05)
    • Rangeland Ecology & Management Editorial Board Volume 72, Number 1 (2019)

      Society for Range Management (Elsevier Inc., 2019-01)
    • Rangeland Ecology & Management Editorial Board Volume 72, Number 2 (2019)

      Society for Range Management (Elsevier Inc., 2019-03)
    • Yak Dung Deposition Affects Litter Mixing Effects on Mass Loss in Tibetan Alpine Grassland

      Liang, D.; Lamb, E.G.; Zhang, S. (Elsevier Inc., 2019-03)
      Plant litter and livestock excreta are two important ways of carbon and nutrient input to soil in grassland grazing systems. Grazing livestock often deposit dung on plant litter, which may affect litter decomposition through a changing microenvironment. We assessed effects of yak dung on litter mixing effects on litter decomposition in a Tibetan alpine grassland. Six common species were selected, including low-quality litter species Kobresia capillifolia, Elymus nutans, and Ligularia virgaurea and high-quality litter species Anemone rivularis, Saussurea nigrescens, and Thermopsis lanceolata. Litter bags containing each species alone and all two-species combinations were allowed to decompose with and without experimental dung addition in the field. Mass loss of the leaf litter was measured after 6 and 12 mo. High-quality litter species had significantly greater mass loss than low-quality litter species. Dung significantly accelerated litter mass loss after both 6 and 12 mo for low-quality litter species, but only after 12 mo for high-quality litter species. Litter mixtures containing both high- and low-quality species showed positive nonadditive effects (NAEs) on mass loss after 6 mo but additive effects after 12 mo. Dung increased the strength of NAEs after 6 mo and shifted litter mixing effects from positive to negative NAEs after 12 mo. Our results support previous findings that litter mixing could produce NAEs on litter decomposition and that these NAEs could change with incubation time. Most importantly, we show that dung can modify NAEs, demonstrating that litter mixing effects are dependent on the microenvironment. Our findings also demonstrate that yak dung can influence soil processes by varying both single-species litter decomposition rates and litter interactions within mixtures. Furthermore, the results suggest yak dung is closely related to material and nutrient cycling, so we believe dung should remain and not be substantially removed from this grazing ecosystem. © 2018 The Society for Range Management
    • Winter Grazing and Rainfall Synergistically Affect Soil Seed Bank in Semiarid Area

      Hu, A.; Zhang, J.; Chen, X.; Chang, S.; Hou, F. (Elsevier Inc., 2019-01)
      The soil seed bank is an important ecological component of grassland restoration and renewal. In semiarid regions, grassland restoration and renewal are highly affected by annual variations in precipitation and grazing activity because these variations can affect the composition, density, richness, and diversity of seeds in the soil. This study aimed to characterize and compare these parameters of the germinable seed bank under different stocking rates in a winter grazing system in a semiarid area of China in 2015 and 2016 (dry and near-average rainfall condition, respectively). The composition, density, richness, and diversity of seeds were determined by the method of seedling emergence. The results showed that a total of 18 species belonging to nine families germinated from the soil. Drought significantly reduced the density, richness, and diversity of the soil seed bank, but grazing was able to significantly increase the richness and diversity of the soil seed bank by increasing the richness and diversity of the aboveground vegetation. The similarity between the soil seed bank and aboveground vegetation was influenced by the rainfall conditions: in the dry year, it was higher at the lower stocking rates (0 and 0.4 animal unit months [AUM] ha–1), and in the near-average rainfall condition year, it was higher at the higher stocking rates (0.8 and 1.3 AUM ha–1). © 2018 The Authors
    • Weather Tools for Retrospective Assessment of Restoration Outcomes

      Moffet, C.A.; Hardegree, S.P.; Abatzoglou, J.T.; Hegewisch, K.C.; Reuter, R.R.; Sheley, R.L.; Brunson, M.W.; Flerchinger, G.N.; Boehm, A.R. (Elsevier Inc., 2019-03)
      Rangeland seeding practices in the Intermountain western United States are predominantly implemented in the year immediately following wildfire for the purposes of Emergency Stabilization and Rehabilitation (ESR). This necessarily links restoration and rehabilitation outcomes to the probability of a single year providing sufficiently favorable microclimatic conditions for desirable plant establishment. Field research studies in rangeland restoration are also typically of limited duration, and published results may not represent the full spectrum of conditions likely to be experienced at a given site. We propose that location-specific and temporal weather analysis may enhance the interpretation of historical planting data, support expanded inferences from short-term field studies, and facilitate meta-analysis of diverse field studies in rangeland restoration. We describe access and use of new databases and tools that can be used to characterize and rank weather and soil-microclimatic variables and suggest some standard graphs and weather metrics to establish a longer-term perspective for the interpretation of rangeland restoration outcomes. Tools of this type may also be useful in the interpretation of a wide range of agricultural and natural resource applications that are driven by similar weather inputs, particularly in arid and semiarid systems that exhibit high annual and seasonal variability in precipitation and temperature. © 2018
    • Ventenata and Other Coexisting Exotic Annual Grass Control and Plant Community Response to Increasing Imazapic Application Rates

      Davies, K.W.; Hamerlynck, E. (Elsevier Inc., 2019-07)
      Ventenata (Ventenata dubia [Leers] Coss.) is an exotic annual grass that can invade intermountain rangeland plant communities, where it can form monotypic stands, degrade wildlife habitat, and reduce livestock forage. There is limited information on ventenata control in rangelands as it has only recently been identified as a substantial problem. Imazapic is a pre-emergent herbicide commonly used to control other exotic annual grasses and, therefore, is likely to control ventenata in rangelands. We evaluated five application rates of imazapic (0 − 175 g ae ∙ ha− 1) on ventenata and other exotic annual grass control and plant community response at two rangeland sites in 2 yr (2014 and 2015). Imazapic reduced exotic annual grass (largely ventenata) cover and density, with greater control with increasing imazapic rates. Exotic annual grass density at the highest levels of control (82%−94%) was 184 − 299 plants ∙ m− 2 the first yr after imazapic application. Exotic annual grasses fully recovered in the second or third yr after imazapic application. Bare ground generally increased with imazapic application. However, density of perennial vegetation (grasses and forbs) did not vary among treatments. Perennial vegetation cover generally did not increase with imazapic control of ventenata and other exotic annual grasses. Imazapic can control ventenata; however, even at the highest rates, control was not enough to shift the dominance from exotic annual species to perennial species. Integrating other treatments with imazapic application may be a strategy to improve ventenata control and increase perennial vegetation and will require further investigation. The difficulty and likely expense of achieving substantial and lasting control of ventenata suggest, similar to other exotic annual grasses, that preventing ventenata invasion and dominance should be a high management priority. © 2019
    • Vegetation, Hydrologic, and Erosion Responses of Sagebrush Steppe 9 Yr Following Mechanical Tree Removal

      Williams, C.J.; Pierson, F.B.; Kormos, P.R.; Al-Hamdan, O.Z.; Nouwakpo, S.K.; Weltz, M.A. (Elsevier Inc., 2019-01)
      Land managers across the western United States are faced with selecting and applying tree-removal treatments on pinyon (Pinus spp.) and juniper (Juniperus spp.) woodland-encroached sagebrush (Artemisia spp.) rangelands, but current understanding of long-term vegetation and hydrological responses of sagebrush sites to tree removal is inadequate for guiding management. This study applied a suite of vegetation and soil measures (0.5 - 990 m2), small-plot rainfall simulations (0.5 m2), and overland flow experiments (9 m2) to quantify the effects of mechanical tree removal (tree cutting and mastication) on vegetation, runoff, and erosion at two mid- to late-succession woodland-encroached sagebrush sites in the Great Basin, United States, 9 yr after treatment. Low amounts of hillslope-scale shrub (3 - 15%) and grass (7 - 12%) canopy cover and extensive intercanopy (area between tree canopies) bare ground (69 - 88% bare, 75% of area) in untreated areas at both sites facilitated high levels of runoff and sediment from high-intensity (102 mm • h- 1, 45 min) rainfall simulations in interspaces (- 45 mm runoff, 59 - 381 g • m- 2 sediment) between trees and shrubs and from concentrated overland flow experiments (15, 30, and 45 L • min- 1, 8 min each) in the intercanopy (371 - 501 L runoff, 2 342 - 3 015 g sediment). Tree cutting increased hillslope-scale density of sagebrush by 5% and perennial grass cover by twofold at one site while tree cutting and mastication increased hillslope-scale sagebrush density by 36% and 16%, respectively, and perennial grass cover by threefold at a second more-degraded (initially more sparsely vegetated) site over nine growing seasons. Cover of cheatgrass (Bromus tectorum L.) was < 1% at the sites pretreatment and 1 - 7% 9 yr after treatment. Bare ground remained high across both sites 9 yr after tree removal and was reduced by treatments solely at the more degraded site. Increases in hillslope-scale vegetation following tree removal had limited impact on runoff and erosion for rainfall simulations and concentrated flow experiments at both sites due to persistent high bare ground. The one exception was reduced runoff and erosion within the cut treatments for intercanopy plots with cut-downed-trees. The cut-downed-trees provided ample litter cover and tree debris at the ground surface to reduce the amount and erosive energy of concentrated overland flow. Trends in hillslope-scale vegetation responses to tree removal in this study demonstrate the effectiveness of mechanical treatments to reestablish sagebrush steppe vegetation without increasing cheatgrass for mid- to late-succession woodland-encroached sites along the warm-dry to cool-moist soil temperature - moisture threshold in the Great Basin. Our results indicate improved hydrologic function through sagebrush steppe vegetation recruitment after mechanical tree removal on mid- to late-succession woodlands can require more than 9 yr. We anticipate intercanopy runoff and erosion rates will decrease over time at both sites as shrub and grass cover continue to increase, but follow-up tree removal will be needed to prevent pinyon and juniper recolonization. The low intercanopy runoff and erosion measured underneath isolated cut-downed-trees in this study clearly demonstrate that tree debris following mechanical treatments can effectively limit microsite-scale runoff and erosion over time where tree debris settles in good contact with the soil surface.
    • Vegetation Responses to Fixed Stocking Densities in Highly Variable Montane Pastures in the Chinese Altay

      Lv, C.; Schlecht, E.; Goenster-Jordan, S.; Buerkert, A.; Zhang, X.; Wesche, K. (Elsevier Inc., 2019-09)
      Variability in aboveground herbaceous biomass and its quality were studied in response to three different stocking densities during a 2-yr grazing experiment with sheep on a montane summer pasture in the Chinese Altay. We determined herbaceous cover and aboveground biomass in 16 paddocks of 0.25 ha each. Vegetation cover showed high spatial variation, prompting us to implement a randomized block design. Forage intake of one male sheep per paddock was quantified four times per grazing season by collection of total feces and estimation of diet digestibility. Sheep weight was recorded every 3 wk. Aboveground herbaceous dry mass (DM) was characterized by pronounced annual variation. Biomass quality declined with progressing season and increasing sheep density. Daily organic matter intake per sheep ranged from 0.7 to 1.4 kg, which was paralleled by a biomass removal of 710 − 1 560 kg DM/ha at densities of 8 − 24 sheep/ha. At 8 sheep/ha, animals gained weight throughout each grazing period, whereas weight losses of 40 − 100 g/d occurred at higher densities. These results challenge the presently followed concept of a fixed stocking density for summer pastures in Altay Prefecture, Xinjian, China. Such practice may result in low herbage allowances and thus deficient sheep nutrition in one year, as well as underutilization of forage resources in another. Flexible adjustment of stocking densities is also advisable for montane pastures where spatiotemporal variability, although less pronounced than in desert steppes of the Altay foothills, is nonetheless highly relevant. © 2019 The Society for Range Management
    • Variation in Surrogate Breeding Habitat Quality Between Continuously Grazed Rangelands and Late-Cut Hayfields for a Threatened Grassland Birds

      Pintaric, A.L.; Reid, R.; Nol, E. (Elsevier Inc., 2019-05)
      Rangelands and hayfields provide a large portion of remaining surrogate habitat for many species of declining grassland birds in North America. We compared late-cut hayfields and continuously grazed pastures at low to moderate cattle densities for providing suitable breeding habitat in eastern Canada for the nationally threatened Bobolink (Dolichonyx oryzivorus). To examine the quality of both habitats, we conducted point counts and monitored 87 nests during the 2015 and 2016 breeding seasons. Bobolink abundance and daily survival rate (DSR) of nests were modeled sequentially by habitat and sex as a function of vegetation structure, prey availability, and agricultural management. Year and habitat were the strongest predictors of abundance. When analyzed separately for pastures and hayfields, vegetation height was most important for female abundance in pastures while pasture size was most important for males. Nests in hayfields had significantly higher daily survival (DSR = 0.98 ± 0.01) than nests in pastures (DSR = 0.94 ± 0.01). Nesting success was highest in hayfields with taller vegetation, while in pastures, no microhabitat variable showed a clear relationship with DSR. Within pastures, cattle stocking densities of ≤ 1 animal units (AU) · ha− 1 were not related to DSR. This study provides evidence that late-cut hay is of highest quality, but that small-scale beef farms with low to moderate stocking densities are suitable targets for conservation efforts of Bobolinks in eastern North America. © 2019 The Society for Range Management
    • Validating a Time Series of Annual Grass Percent Cover in the Sagebrush Ecosystem

      Boyte, S.P.; Wylie, B.K.; Major, D.J. (Elsevier Inc., 2019-03)
      We mapped yearly (2000–2016) estimates of annual grass percent cover for much of the sagebrush ecosystem of the western United States using remotely sensed, climate, and geophysical data in regression-tree models. Annual grasses senesce and cure by early summer and then become beds of fine fuel that easily ignite and spread fire through rangeland systems. Our annual maps estimate the extent of these fuels and can serve as a tool to assist land managers and scientists in understanding the ecosystem's response to weather variations, disturbances, and management. Validating the time series of annual maps is important for determining the usefulness of the data. To validate these maps, we compare Bureau of Land Management Assessment Inventory and Monitoring (AIM) data to mapped estimates and use a leave-one-out spatial assessment technique that is effective for validating maps that cover broad geographical extents. We hypothesize that the time series of annual maps exhibits high spatiotemporal variability because precipitation is highly variable in arid and semiarid environments where sagebrush is native, and invasive annual grasses respond to precipitation. The remotely sensed data that help drive our regression-tree model effectively measures annual grasses’ response to precipitation. The mean absolute error (MAE) rate varied depending on the validation data and technique used for comparison. The AIM plot data and our maps had substantial spatial incongruence, but despite this, the MAE rate for the assessment equaled 12.62%. The leave-one-out accuracy assessment had an MAE of 8.43%. We quantified bias, and bias was more substantial at higher percent cover. These annual maps can help management identify actions that may alleviate the current cycle of invasive grasses because it enables the assessment of the variability of annual grass − percent cover distribution through space and time, as part of dynamic systems rather than static systems. © 2018 The Society for Range Management