• Can Shallow Plowing and Harrowing Facilitate Restoration of Leymus chinensis Grassland? Results From a 24-Year Monitoring Program

      Baoyin, Taogetao; Yonghong Li, Frank (Society for Range Management, 2009-07-01)
      Long-term effects of two mechanical interventions, shallow plowing and harrowing, on degraded Leymus chinensis (Trin.) Tzvel. grassland were studied. Species composition and standing biomass of the grassland were monitored at peak biomass each year for 24 yr after application of these two measures, together with grassland in natural recovery and that under public grazing. Results showed a high resilience of degraded grassland, which recovered naturally after excluding grazing animals to a structure similar to the intact L. chinensis community. In comparison with natural recovery, harrowing facilitated restoration of L. chinensis population and community structure and improved grassland production. Shallow plowing accelerated recovery of L. chinensis population to a larger extent than harrowing and led to a flourish of annual species and improvement of herbage production in the years following its application. But the production improvement was unsustainable and was associated with a decrease in grassland species richness and community complexity. We conclude that the best measure for restoring degraded grassland depends on the restoration objectives and severity of grassland degradation. Harrowing is a feasible technique to assist restoration of the degraded grassland. In contrast, shallow plowing is not appropriate for ecological restoration, but may be applied for quick restoration of herbage production. 
    • Effects of Fire and Neighboring Trees on Ashe Juniper

      Noel, Jill M.; Fowler, Norma L. (Society for Range Management, 2007-11-01)
      The survival of Ashe juniper (Juniperus ashei Buchh.) plants of all sizes was compared between paired burned and unburned plots in four savanna sites on the eastern Edwards Plateau. Smaller plants were less likely to survive a fire than larger plants, over the entire range of plant sizes. Overall fire survival rates varied from <45% (0- to 50-cm-tall plants) to <92% (> 2-m-tall plants). The high rate of survival of small plants indicates that fires like those typically used in this region are not likely to control even the early stages of the encroachment of Ashe juniper. If fire is to be used to maintain savannas in this region, multiple burns, more intense fires, or supplementary mechanical removal will probably be needed. Junipers 0 to 200 cm tall were significantly more likely to be growing under the canopy of a tree (defined as a plant > 2 m tall of any species) than in the open. Small (0 to 50 cm tall) junipers under a tree canopy were significantly more likely to be alive than plants in the same size class growing in the open, suggesting facilitation of small Ashe juniper by neighboring trees. There was, however, no significant effect of neighboring trees on the rate at which small Ashe juniper survived fire, contrary to our initial expectation. 
    • Livestock Grazing and Wildlife: Developing Compatibilities

      Vavra, Martin (Society for Range Management, 2005-03-01)
      Livestock grazing has been considered detrimental to wildlife habitat. Managed grazing programs, however, have the potential to maintain habitat diversity and quality. In cases in which single-species management predominates (sage-grouse [Centrocercus urophasianus] or elk [Cervus elaphus nelsoni] winter range), grazing systems specific to species’ needs can be implemented. Managed livestock grazing can have 4 general impacts on vegetation: 1) alter the composition of the plant community, 2) increase the productivity of selected species, 3) increase the nutritive quality of the forage, and 4) increase the diversity of the habitat by altering its structure. Implementing a grazing management plan to enhance wildlife habitat requires an interdisciplinary approach. Knowledge of plant community dynamics, habitat requirements of affected wildlife species, and potential effects on the livestock used are basic to successful system design. However, any habitat change made for a featured species may create adverse, neutral, or beneficial changes for other species. Management actions, other than development of a grazing system, are often required for habitat manipulations to be successful. More research efforts are needed to understand complementary grazing systems on a landscape scale. 
    • Mesquite and grass interference with establishing redberry juniper seedlings

      Teague, W. R.; Dowhower, S. L.; Whisenant, S. G.; Flores-Ancira, E. (Society for Range Management, 2001-11-01)
      Excessive cover of juniper (Juniperus pinchotii Sudw.) reduces forage production, interferes with livestock management, and diminishes the watershed and wildlife habitat values of rangelands. We studied whether juniper seedlings were differentially suppressed in the presence of different grass species, and to what extent established mesquite (Prosopis glandulosa Torr.) trees facilitated or competed with establishing juniper seedlings. Seedlings growing with any of the grasses (RGR = 0.23 to 0.43 cm cm(-1)) grew significantly less than those with no grass competition (RGR = 0.72 cm cm(-1))(P < 0.01). Juniper seedlings grew significantly less in the presence of buffalograss (Buchloe dactyloides (Nutt.) Engelm.) (RGR = 0.23 cm cm(-1) than with either sideoats grama (Bouteloua curtipendula (Michx.) Torr.) (RGR = 0.43 cm cm(-1)) or tobosagrass (Hilaria mutica [Buckl.] Benth.) (RGR = 0.43 cm cm(-1))(P < 0.01). In contrast, juniper seedlings grew larger under intact canopies of mesquite (RGR = 0.99 cm cm(-1)) than in open grassland (RGR = 0.65 cm cm(-1))(P < 0.05) due in part to the greater nutrient availability (P < 0.05) under mesquite canopies. Juniper growing in sub-canopy positions with mesquite trees removed grew less (RGR = 0.84 cm cm(-1)) than those growing under mesquite canopies with root competition (RGR = 0.99 cm cm(-1))(P < 0.05). Juniper growing under intact mesquite canopies but without mesquite root competition, grew no better or worse (RGR = 0.93 cm cm(-1)) than those with mesquite root competition (RGR = 0.99 cm cm(-1))(P > 0.05), indicating that mesquite root competition with juniper is probably inconsequential. Since junipers grow mainly in fall, winter and spring when mesquite trees are dormant and leafless, the lack of competition may largely be due to these 2 species using resources at different times of the year. Greater nutrient availability beneath mesquite canopies, reduction of summer temperatures, and temporal separation of resource use clearly benefit juniper seedlings growing in the presence of mesquite. Managing for a vigorous grass component with low densities and cover of mesquite is the best way to limit the rate of invasion by juniper.
    • Seedling recruitment of perennial grasses in degraded areas of the Patagonian Monte

      Bisigato, Alejandro Jorge; Bertiller, Monica Beatriz (Society for Range Management, 2004-03-01)
      The recruitment of perennial grass seedlings in degraded areas of the Patagonian Monte was analyzed. Recolonization of large bare-soil areas by dwarf shrubs or perennial grasses was hypothesized to create favorable microsites for grass seedling recruitment. Under natural field conditions, soil moisture (0-20 cm), root biomass (0-20 cm), the soil seed bank of perennial grasses, and density of perennial grass seedlings in the center of large bare soil areas and in microsites neighboring isolated plants of perennial grasses and dwarf shrubs were assessed. A manipulative experiment was conducted to evaluate seedling recruitment at the 3 microsites with identical density of seed addition of perennial grasses, under situations of root exclusion, and water addition. Under natural field conditions, root biomass did not differ among microsites. Soil moisture, seed density, and seedling density of perennial grasses were higher near perennial grasses than in bare soil or next to dwarf shrubs. Recruitment of perennial grass seedlings did not differ among microsites when the density of seeds did not vary among them or roots of the established plants were excluded. Water increased perennial grass seedling recruitment at all microsites. In degraded areas of the Patagonian Monte the spatial distribution of the soil seed bank followed by water availability are the main limiting factors of seedling recruitment of perennial grasses. Managerial practices oriented to maintain and increase the soil seed bank of perennial grasses, such as grazing exclusion during the grass reproductive period, might contribute to promote the re-establishment of perennial grasses.
    • The Spatial Patterns of Functional Groups and Successional Direction in a Coastal Dune Community

      Feagin, Rusty A.; Wu, X. Ben (Society for Range Management, 2007-07-01)
      Various methods have been devised to classify plants into functional groups, yet little work has investigated how these groups differentially impact succession with spatially explicit mechanisms. In a sand dune plant community on Galveston Island, Texas, we categorized plants by their functional traits, mapped the topographical contours of the sand dunes as a first-order effect to describe the spatial distribution of environmental stress, and quantified the second-order within- and between-group associations of the plants within specific bands of these contours using Ripley’s K analysis. We then quantified the influence of spatially explicit functional traits on the direction of succession over time. We found evidence that the spatial pattern of the plants at one time exerted an influence on the pattern of the plants at a later time, based on their functional traits, thereby influencing the direction of sand dune succession. This study describes the spatiotemporal mechanics that lie behind sand dune plant succession: a process that has been a classical example of facilitation for ecologists, a plant community that is at risk from global sea-level rise and hurricanes, and an important rangeland resource that is being restored around the world for its ecological, range production, and coastal protection value. 
    • View Point: Choosing a Reclamation Seed Mix to Maintain Rangelands During Energy Development in the Bakken

      Espeland, Erin K. (Society for Range Management, 2014-02-01)
      On the Ground • Pipelines across the eastern Montana–western North Dakota portion of the northern Great Plains are proliferating due to continuing oil and gas development. • Pipelines are linear disturbances reclaimed after construction, and they impact a large number of livestock producers. • While livestock are usually removed from pastures during the construction phase, proper reclamation and revegetation paired with informed grazing management may return pastures to use quickly and profitably. • Research is needed to determine how the simultaneous seeding of an annual cover crop with desired perennial grasses can enhance livestock production while ensuring the success of perennial grass forage species.