• Using Participatory Workshops to Integrate State-and-Transition Models Created With Local Knowledge and Ecological Data

      Knapp, Corrine Noel; Gimenez, Maria Fernandez; Kachergis, Emily; Rudeen, Aleta (Society for Range Management, 2011-03-01)
      State-and-transition models (STMs) depict current understanding of vegetation dynamics and are being created for most ecological sites in the United States. Model creation is challenging due to inadequate long-term data, and most STMs rely on expert knowledge. There has been little systematic documentation of how different types of knowledge have been integrated in STMs, or what these distinct knowledge sources offer. We report on a series of participatory workshops where stakeholders helped to integrate STMs developed for the same region using local knowledge and ecological field data. With this exploratory project, we seek to understand what kinds of information local knowledge and ecological field data can provide to STMs, assess workshops as a method of integrating knowledge and evaluate how different stakeholders perceive models created with different types of knowledge. Our analysis is based on meeting notes, comments on draft models, and workshop evaluation questionnaires. We conclude that local knowledge and ecological data can complement one another, providing different types of information at different spatial and temporal scales. Participants reported that the workshop increased their knowledge of STMs and vegetation dynamics, suggesting that engaging potential model users in developing STMs is an effective outreach and education approach. Agency representatives and ranchers expressed the value of both the local knowledge and data-driven models. Agency participants were likely to critique or add components based on monitoring data or prior research, and ranchers were more likely to add states and transitions based on personal experience. As STM development continues, it is critical that range professionals think systematically about what different forms of data might contribute to model development, how we can best integrate existing knowledge and data to create credible and useful models, and how to validate the resulting STMs.
    • Influence of Grazing Management on Plant Diversity of Highland Sourveld Grassland, KwaZulu-Natal, South Africa

      O'Connor, Tim G.; Martindale, Greg; Morris, Craig D.; Short, Alan; Witkowski, Ed T. F.; Scott-Shaw, Rob (Society for Range Management, 2011-03-01)
      Commercial livestock production offers one of the main opportunities for mainstreaming of biodiversity conservation in the grassland biome of South Africa. Grazing management is expected to influence success. With the uses of three long-term grazing trials, effects of stocking rate and cattle-to-sheep ratio on the plant composition and diversity of Highland Sourveld grassland in KwaZulu-Natal were examined. Plant diversity was sampled with the use of modified Whittaker plots. Canonical correspondence analysis was used to test the effects of treatments on compositional variation, and general linear models were used to test individual species’ responses. In a biennial rotation, burned/grazed plots supported lower species richness of forbs and all plants than unburned/ungrazed plots, attributed to the impact of grazing during the season of occupation. A high stocking rate resulted in a long-term decrease of forb richness in one experiment, but an increase in another. An increasing proportion of sheep to cattle resulted in a long-term decrease of the richness of forbs and of total species richness. The three trials identified nongrass species that behaved as increasers or decreasers in response to an increase in stocking rate, and a set of species that behaved as decreasers in response to an increasing proportion of sheep to cattle. Constraints on using long-term trials for identifying the effects of livestock management on plant diversity include lack of baseline data, limited replication, pre-experimental impacts on the study site, and the difficulty of assessing uncommon species.
    • Fire Effects on the Cheatgrass Seed Bank Pathogen Pyrenophora semeniperda

      Beckstead, Julie; Street, Laura E.; Meyer, Susan E.; Allen, Phil S. (Society for Range Management, 2011-03-01)
      The generalist fungal pathogen Pyrenophora semeniperda occurs primarily in cheatgrass (Bromus tectorum) seed banks, where it causes high mortality. We investigated the relationship between this pathogen and its cheatgrass host in the context of fire, asking whether burning would facilitate host escape from the pathogen or increase host vulnerability. We used a series of laboratory and field experiments to address the ability of host seeds and pathogen life stages to survive fire. First, we determined the thermal death point (TDP50; temperature causing 50% mortality) of seeds and pathogen propagules at two time intervals using a muffle furnace. We then measured peak fire temperatures in prescribed burns at sites in Utah and Washington and quantified seed and fungal propagule survival using pre- and postburn seed bank sampling and inoculum bioassays. Finally, we investigated the survival of both seeds and pathogen after wildfires. We found that radiant heat generated by both prescribed and wild cheatgrass monoculture fires was generally not sufficient to kill either host seeds or pathogen propagules; most mortality was apparently due to direct consumption by flames. The 5-min mean TDP50 was 164 degreesC for pathogen propagules and 148 degreesC for host seeds, indicating that the pathogen is more likely to survive fire than the seeds. Peak fire temperature at the surface in the prescribed burns averaged 130 degreesC. Fire directly consumed 85-98% of the viable seed bank, but prescribed burns and wildfires generally did not lead to dramatic reductions in pathogen inoculum loads. We conclude that the net effect of fire on this pathosystem is not large. Rapid postburn recovery of both host and associated pathogen populations is the predicted outcome. Postfire management of residual cheatgrass seed banks should be facilitated by the persistent presence of this seed bank pathogen.
    • Measuring Eastern Redcedar (Juniperus virginiana L.) Mass With the Use of Satellite Imagery

      Starks, Patrick J.; Venuto, Brad C.; Eckroat, John A.; Lucas, Tom (Society for Range Management, 2011-03-01)
      Eastern redcedar (Juniperus virginiana L.) is an aggressively spreading native species in Oklahoma grasslands. It decreases rangeland forage production, and has been implicated in reducing stream flow and groundwater recharge. Industrial-scale plans to use redcedar as a biofuel source are being considered. Optimal placement of redcedar-based industries requires determination of redcedar availability. Such large-area inventories of redcedar mass can be practically addressed via aircraft or satellite remote sensing. Therefore, we conducted a study in central and western Oklahoma to develop and test a remote-sensing-based allometric equation relating redcedar canopy area to aboveground dry mass (AGM). We used automated methods to measure tree canopy area from georectified, pan-sharpened, multispectral QuickBird images having a spatial resolution of 0.45 m2 per pixel ground sample area. We also measured the canopy area and fresh and dry mass of these trees with the use of destructive sampling techniques. Regression analysis showed that satellite-derived measurements of canopy coverage explained about 85% of field-measured redcedar dry AGM in the study plots. The resulting allometric equation was applied to an independent data set, yielding dry AGM of 38.2 metric tons ha-1, which was well within the field-measured range of 36-43 metric tons ha-1. The allometric equation was then applied to Natural Resources Conservation Service measurements of redcedar canopy coverage for 17 counties in Oklahoma, to determine that the area of interest contains a median value of about 11.5 million metric tons of redcedar AGM. These results indicate that 0.45-m2 spatial resolution multispectral imagery can be a useful tool for rapid and reliable measurement of redcedar dry AGM.
    • Using Digital Photography to Examine Grazing in Montane Meadows

      McIlroy, Susan K.; Allan-Diaz, Barbara H.; Berg, Alexander C. (Society for Range Management, 2011-03-01)
      Cattle (Bos taurus) numbers on national forests are allocated based on allotment grazing capacity, but spatial patterns of timing and density at smaller scales are difficult to assess. However, it is often in meadows or riparian areas that grazing may affect hydrology, biodiversity, and other important ecosystem characteristics. To explore real-time animal presence in montane meadows we distributed 18 digital cameras across nine sites in the Sierra National Forest, California. Our objectives were to document seasonal and diurnal presence of both cattle and mule deer (Odocoileus hemionus), identify the effects of three fencing treatments on animal distribution, and test digital photography as a tool for documenting cattle presence. We recorded 409 399 images during daylight hours for two grazing seasons, and we identified 5 084 and 24 482 cattle ‘‘marks’’ (instances of animal occurrence) in 2006 and 2007, respectively. Deer presence was much lower, with 331 marks in 2006 and 598 in 2007. Morning cattle presence was highest before 0800 hours both years (13.7% and 15.4% of total marks for 2006 and 2007, respectively). Marks decreased until 1100 hours and then increased around 1400 hours and remained relatively stable until 1900 hours. Marks then rose precipitously, with > 20% of total marks recorded after 1900 hours both years. Deer presence was less than 10% per hour until 1800 hours, when >20% of total marks were recorded after this time both years. Among treatments, cattle marks were highest outside fences at partially fenced meadows, and deer were highest within completely fenced meadows. Our experience suggests that cameras are not viable tools for meadow monitoring due to variation captured within meadows and the time and effort involved in image processing and review.
    • Spring Precipitation as a Predictor for Peak Standing Crop of Mixed-Grass Prairie

      Wiles, L. J.; Dunn, Gale; Printz, Jeff; Patton, Bob; Nyren, Anne (Society for Range Management, 2011-03-01)
      Ranchers and range managers need a decision support tool that provides a reasonably accurate prediction of forage growth potential early in the season to help users make destocking decisions. Erroneous stocking rate decisions can have dire economic and environmental consequences, particularly when forage production is low. Predictions must be based on information that is easily obtained and relevant to the particular range. Our goal was to evaluate monthly precipitation in spring months as a potential predictor of forage production compared to annual and growing-season precipitation. We analyzed the relationships between grazed and ungrazed peak standing crop (PSC) and precipitation using nonlinear regression and a plateau model, Akaike’s information criterion for model selection, and data from three locations: Streeter, North Dakota; Miles City, Montana; and Cheyenne, Wyoming. The plateau model included a linear segment, representing precipitation limiting production, and a plateau, an estimate of average production when precipitation is no longer the limiting factor. Both the response and predictor variables were rescaled so variability in production from average production was related to variability in precipitation from the long-term average. We found that grazing did not affect the relationship between PSC and precipitation, nor were annual or growing-season precipitation good predictor variables. The best predictor variable was total precipitation in April and May for Montana, May and June for North Dakota, and April, May, and June for Wyoming, with r2 ranging from 0.74 to 0.79 for precipitation less than long-term average. These results indicate that spring precipitation provides useful information for destocking decisions and can potentially be used to develop a decision support tool, and the results will guide our choice of possible predictor models for the tool.
    • Vegetation Production Responses to October Grazing in the Nebraska Sandhills

      Mousel, Eric M.; Schacht, Walter H.; Reece, Patric E.; Herron, Amy E.; Koehler, Ann (Society for Range Management, 2011-03-01)
      Understanding the long-term effect of summer grazing date and fall stocking rate on herbage production is critical to extending the grazing season in the Nebraska Sandhills. A study was conducted from 1997 to 2002 at the Gudmundsen Sandhills Laboratory located near Whitman, Nebraska, to determine the herbage production response to summer grazing date and October stocking rate on two different sites. Site 1 was dominated by warm-season grasses and site 2 was dominated by cool- season graminoids. At each site, three 0.37-ha pastures were constructed in each of four blocks before application of summer grazing treatments. Pastures in each block were grazed at 0.5 animal-unit months (AUM) ha-1 in June or July, or were deferred from summer grazing. Following summer grazing treatments, October stocking rate treatments (no grazing or 1.0, 2.0, or 3.0 AUM ha-1) were applied to subunits of each summer grazing date pasture during mid-October. Vegetation was sampled in each pasture in mid-June and mid-August and sorted by functional group to determine the effect of 5 yr of grazing treatments on herbage production and residual herbage. Herbage production was not affected by summer or October grazing treatments on the warm-season grass-dominated site. Increasing October stocking rate, however, reduced cool-season graminoid production and subsequent herbage production 25% by year 5 of the study. Residual herbage at both sites at the end of the October grazing periods explained as much as 16% to 34% of subsequent year’s herbage production. Grazing managers in the Nebraska Sandhills can extend the grazing season by lightly stocking pastures in the summer to facilitate additional fall grazing. Heavy stocking in October over several years on cool-season-, but not warm-season-, dominated sites will reduce production of cool- season graminoids on these sites.
    • Disturbance to Surface Lithic Components of Archaeological Sites by Drill Seeding

      Bryan, Neal M.; Anderson, Val Jo; Fugal, Rachel A. (Society for Range Management, 2011-03-01)
      Federally funded range improvement treatments in the United States require that land managers consider the treatment’s impacts to archaeological sites. Pending archaeological clearance can result in the postponement or exclusion of effective seeding practices, which in turn can result in poor seed establishment, increased weeds, recurrent fire, accelerated soil erosion, and damage to cultural sites. Less intensive requirements would help relieve time restrictions, but less-conspicuous sites might be missed. We quantified the displacement and damage that lithic artifacts would incur if missed in an inventory and subsequently subjected to drill seeding treatments. We subjected chert, quartzite, and obsidian materials to impact by a rangeland drill and a no-till drill on sandy and silty soils. Soil texture was the most important factor in perpendicular lithic movement. In the silty soil, lithics were displaced perpendicular to the direction of the drill nearly twice as far as in the sandy soil (7.8 cm +/- 0.9 SE vs. 4.1 cm +/- 0.6 SE, P < 0.01). No experimental factor showed a difference in absolute displacement (mean = 15 cm). Damage to lithics was infrequent (25%) and minor with no experimental factor showing statistical significance. Approximately 30% of lithics were buried by treatments. In the sandy soil, the rangeland drill buried lithics 6.5 mm +/- 1.6 SE deep, on average, which was twice as deep as the no-till drill in the sandy soil (3.0 mm +/- 0.9 SE) and four times as deep as both drills in the silty soil (1.5 mm 60.5 SE; =50.03). Minimal effects of drill seeding on lithics suggest that drill seeding could proceed with less- intensive archaeological surveys.
    • Aspen Recovery Since Wolf Reintroduction on the Northern Yellowstone Winter Range

      Kimble, David S.; Tyers, Daniel B.; Robinson-Cox, Jim; Sowell, Bok F. (Society for Range Management, 2011-03-01)
      Quaking aspen (Populus tremuloides Michx.) recruitment and overstory stem densities were sampled in 315 clones in 1991 and 2006 on 560 km2 of the Northern Yellowstone Winter Range (NYWR). A primary objective was to observe if aspen status had improved from 1991 to 2006: evidence of a wolf (Canis lupus) caused trophic cascade. Recruitment stems (height > 2 m and diameter at breast height < 5 cm) represent recent growth of aspen sprouts above elk (Cervus elaphus) browsing height, whereas overstory stems (all stems > 2 m) represent the cohort of stems, which will insure the sustainability of the clone. Overstory stem densities declined by 12% (P = 0.04) on the landscape scale when compared with paired t-tests. Overstory stems declined in 58% of individual clones and in 63% of the 24 drainages of the study area. The second objective was to determine which factors influenced changes in aspen density. Winter ungulate browsing (P=0.0001), conifer establishment (P=0.0001), and cattle (Bos spp.) grazing (P = 0.016) contributed to the decline in overstory stem densities when analyzed using a mixed effects model of log transformed medians. Eighty percent of the clones were classified as having medium to high browsing levels in 1991, whereas 65% of the clones received a similar rating in 2006, possibly due to the reduced NYWR elk population. Aspen recruitment has increased in some 2-10 km2 areas, but not consistently. Our study found that a trophic cascade of wolves, elk, and aspen, resulting in a landscape-level recovery of aspen, is not occurring at this time.
    • Wildlife Responses to Long-Term Application of Biosolids to Grasslands in North Carolina

      Washburn, Brian E.; Begier, Michael J. (Society for Range Management, 2011-03-01)
      Applications of biosolids to grassland areas might alter the attractiveness of those habitats to wildlife. For the past 21 yr, biosolids have been applied annually to grasslands at Marine Corps Air Station (MCAS) Cherry Point, Havelock, North Carolina. During 2003-2005, we conducted a study to determine if the long-term application of biosolids has altered plant communities and/or wildlife use of grassland areas. Ten circular 1.7-ha plots were established: five plots served as controls (untreated) and five plots were located in areas that received biosolids. We monitored vegetation growth, measured plant community composition, and observed all plots for wildlife activity during December 2003 through December 2005. Long-term application of biosolids to grasslands at MCAS Cherry Point has altered the botanical structure and composition of those areas. Plant communities in grassland areas receiving biosolids were taller (P < 0.001), denser (P < 0.001), and less diverse (P < 0.001) than control areas that did not receive biosolids. Biosolids study plots were dominated by tall fescue (Lolium arundinaceum [Schreb.] S.J. Darbyshire), whereas control plots consisted of a diversity of grasses, forbs, and woody plants. We observed more (P < 0.001) total birds 3-min survey-1 using biosolids treatment plots (6.7 +/- 0.5 birds; x +/- SE) than birds using control (2.6 +/- 0.2 birds) plots. Species-specific differences in use of biosolids and control grasslands did occur and was often related to season. We observed no differences in white-tailed deer (Odocoileus virginianus) use of biosolids and control areas when examining information from two types of deer surveys. Long-term biosolids application to cool-season grasslands alters plant communities and favors use of those areas by some grassland birds.
    • Transition From Sagebrush Steppe to Annual Grass (Bromus tectorum): Influence on Belowground Carbon and Nitrogen

      Rau, Benjamin M.; Johnson, Dale W.; Blank, Robert R.; Lucchesi, Annmarrie; Caldwell, Todd G.; Schupp, Eugene W. (Society for Range Management, 2011-03-01)
      Vegetation changes associated with climate shifts and anthropogenic disturbance have major impacts on biogeochemical cycling. Much of the interior western United States currently is dominated by sagebrush (Artemisia tridentata Nutt.) ecosystems. At low to intermediate elevations, sagebrush ecosystems increasingly are influenced by cheatgrass (Bromus tectorum L.) invasion. Little currently is known about the distribution of belowground organic carbon (OC) on these changing landscapes, how annual grass invasion affects OC pools, or the role that nitrogen (N) plays in carbon (C) retention. As part of a Joint Fire Sciences-funded project called the Sagebrush Treatment Evaluation Project (SageSTEP), we quantified the depth distribution of soil OC and N at seven sites experiencing cheatgrass invasion. We sampled plots that retained sagebrush, but represented a continuum of cheatgrass invasion into the understory. Eighty-four soil cores were taken using a mechanically driven diamond- tipped core drill to a depth of 90 cm, or until bedrock or a restrictive layer was encountered. Samples were taken in 15-cm increments, and soil, rocks, and roots were analyzed for OC and total N. We determined that cheatgrass influences the vertical distribution of OC and N within the soil profile and might result in decreased soil OC content below 60 cm. We also found that OC and total N associated with coarse fragments accounted for at least 10% of belowground pools. This emphasizes the need for researchers to quantify nutrients in deep soil horizons and coarse fragments.
    • Songbird Relationships to Shrub-Steppe Ecological Site Characteristics

      Williams, Mary I.; Paige, Ginger B.; Thurow, Thomas L.; Hild, Ann L.; Gerow, Kenneth G. (Society for Range Management, 2011-03-01)
      Rangeland managers are often faced with the complex challenge of managing sites for multiple uses and for the diverse interests of stakeholders. Standardized monitoring methods that can be used and understood by different agencies and stakeholders would aid management for long-term sustainability of rangelands. In the United States, federal land management agencies have recently based their assessments of rangeland health and integrity on state-and-transition models to consider management trajectories. Ecological sites provide a foundation for these efforts but have not been used to address wildlife habitat. Habitat preferences are documented for North American shrub-steppe songbirds but have yet to be related to ecological sites and site characteristics. We characterized ecological sites at Browns Park National Wildlife Refuge, Colorado, using established rangeland monitoring methods to test whether 1) songbird species density and diversity differ among adjacent shrub-steppe ecological sites and 2) quantifiable ecological site characteristics could be identified that account for significant variation in songbird density and diversity. Vegetation structure (represented as basal and canopy gaps, cover, height, and shrub density) differentiated the four ecological sites and was related to songbird density and diversity. Sage sparrows (Amphispiza belli) and vesper sparrows (Pooecetes gramineu) selected habitat based on horizontal characteristics of vegetation structure, such as basal and canopy gap and plant species cover. Brewer’s sparrow (Spizella breweri), lark sparrow (Chondestes grammacus), and songbird diversity were more strongly related to vegetation structure of the plant communities than to plant composition. Our results support use of ecological sites as management units to characterize songbird habitat given that songbird density and diversity were related to site vegetation characteristics. By incorporating basal and canopy gap, height, plant cover, and shrub density monitoring methods into ecological site descriptions, managers would be provided with additional tools to assist in differentiating songbird habitat.