• Abundances of coplanted native bunchgrasses and crested wheatgrass after 13 years

      Nafus, A. M.; Svejcar, T. J.; Ganskopp, D. C.; Davies, K. W. (Society for Range Management, 2015-03)
      Crested wheatgrass (Agropyron cristatum [L] Gaertm) has been seeded on more than 5 million hectares in western North America because it establishes more readily than native bunchgrasses. Currently, there is substantial interest in reestablishing native species in sagebrush steppe, but efforts to reintroduce native grasses into crested wheatgrass stands have been largely unsuccessful, and little is known about the long-term dynamics of crested wheatgrass/native species mixes. We examined the abundance of crested wheatgrass and seven native sagebrush steppe bunchgrasses planted concurrently at equal low densities in nongrazed and unburned plots. Thirteen years post establishment, crested wheatgrass was the dominant bunchgrass, with a 10-fold increase in density. Idaho fescue (Festuca idahoensis Elmer), Thurber's needlegrass (Achnatherum thurberianum (Piper) Barkworth), basin wildrye (Leymus cinereus [Scribn. & Merr.] A. Löve), and Sandberg bluegrass (Poa secunda J. Presl) maintained their low planting density, whereas bluebunch wheatgrass (Pseudoroegneria spicata [Pursh] A. Löve), needle-and-thread (Hesperostipa comata [Trin. & Rupr.] Barkworth), and squirreltail (Elymus elymoides [Raf.] Swezey) densities declined. Our results suggest that densities of native bunchgrasses planted with crested wheatgrass are unlikely to increase and that some species may only persist at low levels. The high recruitment of crested wheatgrass suggests that coplanting of some native bunchgrasses may be a viable way of avoiding crested wheatgrass monocultures when this species is necessary for rehabilitation or restoration. © 2015 Society for Range Management. Published by Elsevier Inc. All rights reserved.
    • Avian habitat following grazing native warm-season forages in the mid-south United States

      Harper, C. A.; Birckhead, J. L.; Keyser, P. D.; Waller, J. C.; Backus, M. M.; Bates, G. E.; Holcomb, E. D.; Brooke, J. M. (Society for Range Management, 2015-03)
      Native warm-season grasses (NWSG) currently are being promoted for livestock forage and biofuels feedstock in the Mid-South. However, there are no published data on how NWSG managed with livestock in the Mid-South may affect habitat for wildlife. We conducted a study to evaluate habitat for grassland songbirds and northern bobwhite (Colinus virginianus) in response to two cattle grazing treatments in NWSG pastures across three sites in Tennessee, 2010 and 2011. We evaluated vegetation composition and structure along with invertebrate availability during the primary nesting season for grassland songbirds and the typical brood-rearing season for the northern bobwhite. Grazing treatments included full-season (May to August) grazing and early-season (30 days beginning in May) grazing, after which subsequent growth was taken as a biofuel harvest postdormancy. Forage treatments included big bluestem/indiangrass mixture, switchgrass, and eastern gamagrass. Vegetation composition was dominated by the planted forages in all pastures. All forage types and both grazing treatments provided suitable structure for grassland songbirds and bobwhite during the primary nesting season. Full-season grazing maintained suitable structure through the brooding period, with greater openness at the ground level and angle of obstruction, as well as optimal vegetation height (<60 cm). Structure within early-season grazing treatments became dense after cattle were removed with less openness at ground level than what brooding bobwhites typically use. Invertebrate biomass was sufficient in all forage types and grazing treatments to support bobwhite broods. We recommend livestock producers in the Mid-South use full-season grazing that maintains grass height of approximately 40 cm in production stands of NWSG to maximize benefits for grassland birds and northern bobwhite. © 2015 Society for Range Management. Published by Elsevier Inc. All rights reserved.
    • Genetic influences on cattle grazing distribution: Association of genetic markers with terrain use in cattle

      Bailey, D. W.; Lunt, S.; Lipka, A.; Thomas, M. G.; Medrano, J. F.; Cánovas, A.; Rincon, G.; Stephenson, M. B.; Jensen, D. (Society for Range Management, 2015-03)
      Eighty-seven cows were GPS (Global Positioning System) tracked for 1 to 3 months in mountainous and/or extensive pastures at five ranches located in New Mexico, Arizona, and Montana. The Illumina Bovine HD SNP array, which evaluates approximately 770,000 genetic markers (i.e., single nucleotide polymorphisms; SNPs) across the 30 bovine chromosomes, was used to genotype DNA from these cows and to examine genetic associations with grazing distribution. Terrain use indexes were calculated from tracking data based on normalized averages of slope use, elevation use, and distance travelled from water. Genetic analyses identified a chromosomal region, known as a quantitative trait locus (QTL), associated with these traits. One genetic marker on chromosome 29 identified a gene that has been reported to be involved in locomotion, motivation, and spatial memory. This locus accounted for 24% of the phenotypic variation in use of steep slopes and high elevations, while another QTL on chromosome 17 accounted for 23% of the phenotypic variation. Three other QTLs accounted for 10% to 20% of the variation in terrain use indexes. Using results from the initial high-density genetic marker analyses, a smaller 50-SNP panel was developed targeting previously identified QTL regions and was used to evaluate the 85 cows tracked previously with an additional 73 cows from four ranches. With the 50-SNP panel analyses, multiple genetic markers near or within the gene identified on chromosome 29 confirmed the association with indexes of terrain use. In addition, genetic markers on chromosomes 4, 8, 12, and 17 accounted for a significant portion of the phenotypic variation in terrain use indexes. The associations between terrain use indexes and genetic markers near candidate genes demonstrate that grazing distribution can be inherited and provide a new approach to associate genetic variation with cattle grazing behavior of range beef cattle. © 2015 Society for Range Management. Published by Elsevier Inc. All rights reserved.
    • Honey mesquite (prosopis glandulosa) seedling responses to seasonal timing of fire and fireline intensity

      James Ansley, R.; Kramp, B. A.; Jones, D. L. (Society for Range Management, 2015-03)
      Fire-resistant woody species have invaded many grassland and savanna ecosystems worldwide. Adults of many of these species are fire resistant because they resprout following fire; however, seedlings may be vulnerable to fire. Here we quantify effects of seasonal timing of fire and fireline intensity on seedling mortality response to fire in honey mesquite (Prosopis glandulosa Torr.), a native woody legume that has increased in abundance in southern Great Plains, USA grasslands. Scarified mesquite seeds were planted in plots with either mid-grass or tall-grass fuels in each of 2 years (Cohorts 1 and 2). Plots were burned in winter when seedlings were 10 or 22 months old or late summer when they were 17 months old. In the mid-grass fuel type, seedling mortality was greater (P ≤ 0.05) in summer-burned, 17-month-old seedlings (85%) than in winter-burned, 10-month-old seedlings (35%), suggesting summer fire may be important in limiting seedling establishment under lower-grass, fine-fuel conditions. The tall-grass fuel type yielded similar mortality responses to summer (89% and 79%) and winter (77% and 66%) fires in Cohorts 1 and 2, respectively (differences not significant at P ≤ 0.05). The study found a positive relationship between fireline intensity and seedling mortality, especially when only winter fires were included in the regression (r2 = 0.96). Summer fire may be most useful in lower-grass fuel amounts and may accomplish the same level of seedling mortality without the need for lengthy grazing deferral to accumulate sufficient grass fine fuel for a successful winter fire, as seedling mortality from winter fire depends on fireline intensity. © 2015 Society for Range Management. Published by Elsevier Inc. All rights reserved.
    • Management regimen and seeding rate modify seedling establishment of leymus Chinensis

      Liu, G. X.; He, F.; Wan, L. Q.; Li, X. L. (Society for Range Management, 2015-03)
      Broadcasting of Chinese wild rye, Leymus chinensis seeds (without plowing) is the long-standing recommendation for reseeding degraded grasslands in Northern China. However, no experimental assessments have been made to determine which management options, including presow harrowing, postsow cutting, nitrogen fertilizer, and seeding rate, may influence the establishment of L. chinensis seedlings after broadcasting. We conducted a 2-year field study that quantified the relative impacts of these factors on seedling emergence, survival, and growth on a degraded short-grass steppe site at SaiBei, Hebei Province, China. Broadcast seeding of L. chinensis after harrowing resulted in the highest seedling emergence (16.4%), seedling survival (62.5%), and plant height (8.5 cm) compared with the other management regimens assessed. By Year 2, survival was 10 times greater in plots where harrowing had been implemented. This finding was especially important because of the drought conditions that occurred during the study period. The lowest seeding rate (400 seeds m-2) was linked with 15% seedling emergence and average heights of 7.3 cm at the end of the 2 years. It is our recommendation that seedling establishment is optimized when harrowing is used for initial soil preparation and seed dispersal. Harrowing improved seed-soil contact, increased the number of seed safe sites on the soil surface, and reduced competition from the already existing sward. © 2015 Society for Range Management. Published by Elsevier Inc. All rights reserved.
    • Monitoring the impact of grazing on rangeland conservation easements using MODIS vegetation indices

      Tsalyuk, M.; Kelly, M.; Koy, K.; Getz, W. M.; Scott, Butterfield, H. (Society for Range Management, 2015-03)
      Monitoring the effects of grazing on rangelands is crucial for ensuring sustainable rangeland ecosystem function and maintaining its conservation values. Residual dry matter (RDM), the dry grass biomass left on the ground at the end of the grazing season, is a commonly used proxy for rangeland condition in Mediterranean climates. Moderate levels of RDM are correlated with soil stability, forage production, wildlife habitat, and diversity of native plants. Therefore RDM is widely monitored on rangeland conservation properties. Current ground-based methods for RDM monitoring are expensive, are labor intensive, and provide information in the fall, after the effects of grazing have already occurred. In this paper we present a cost-effective, rapid, and robust methodology to monitor and predict RDM using Moderate Resolution Imaging Spectroradiometer (MODIS) satellite data. We performed a time series analysis of three MODIS-based vegetation indices (VIs) measured over the period 2000-2012: Normalized Difference Vegetation Index (NDVI), Leaf Area Index (LAI), and Fraction of Photosynthetically Active Radiation (FPAR). We examined the correlation between the four VIs and fall RDM measured at The Nature Conservancy's Simon Newman Ranch in central California. We found strong and significant correlations between maximum VI values in late spring and RDM in the fall. Among the VIs, LAI values had the most significant correlation with fall RDM. MODIS-based multivariate models predicted up to 63% of fall RDM. Importantly, maximum and sum VIs values were significantly higher in management units with RDM levels in compliance with RDM conservation easement terms compared with units out of compliance. On the basis of these results, we propose a management model that uses time series analysis of MODIS VIs to predict forage quantities, manage stocking rates, and monitor rangeland easement compliance. This model can be used to improve monitoring of rangeland conservation by providing information on range conditions throughout the year. © 2015 Society for Range Management. Published by Elsevier Inc. All rights reserved.
    • Time of grazing effect on subsequent-year standing crop in the Eastern Nebraska Sandhills

      Stephenson, M. B.; Schacht, W. H.; Volesky, J. D.; Eskridge, K. M.; Bauer, D. (Society for Range Management, 2015-03)
      Rotational grazing methods provide range managers opportunities to alter the time when grazing occurs on pastures in consecutive years. The effect of time of grazing on subsequent-year standing crop was evaluated within four pastures (42 ± 1 ha) rotated annually within a deferred rotation using a modified Williams design that included mean times of grazing within different pastures from 16 May to 14 June, 13 June to 20 July, 20 July to 29 August, and 27 August to 7 October (i.e., stages of grazing A, B, C, and D, respectively). Subsequent-year standing crop of different plant functional groups was collected from 2001 to 2008 at four topographic positions (i.e., north slopes, south slopes, dune tops, and interdunes) in mid-June and mid-August harvests. During the mid-June harvest, standing crop of subsequent-year warm-season grasses was 51 ± 24 to 117 ± 41 kg·ha-1 greater (P &lt; 0.1) when grazing occurred during stage A compared with when grazing occurred during stages B and C on north- and south-facing slopes and at the pasture level. During the mid-August harvest on south-facing slopes, subsequent-year warm-season grass standing crop was 265 ± 105 and 341 ± 113 kg·ha-1 greater (P &lt; 0.03) when grazing occurred during stage A compared with stages B and C, respectively. Overall, grazing on pastures during stage A tended to provide greater amounts of subsequent-year standing crop for warm-season and cool-season graminoids at specific topographic positions. Given that the effect of time of grazing on subsequent-year standing crop varied among topographic positions for different functional groups, a deferred grazing rotation provides a viable management tool to alter the yearly sequence of grazing on pastures to avoid negative effects of grazing Nebraska Sandhills vegetation at critical times in consecutive years. © 2015 Society for Range Management. Published by Elsevier Inc. All rights reserved.
    • Weather constrains the influence of fire and grazing on nesting greater prairie-chickens

      Hovick, T. J.; Dwayne, Elmore, R.; Fuhlendorf, S. D.; Dahlgren, D. K. (Society for Range Management, 2015-03)
      Grasslands are highly imperiled as a result of widespread conversion for agriculture and alteration from human development. Remaining grasslands are susceptible to mismanagement, development and fragmentation, and variable weather associated with global climate change. Understanding the response of declining grassland species to these challenges will be important for informed conservation and management. We assessed Greater Prairie-Chicken (Tympanuchus cupido) survival and nest site selection in tallgrass prairie characterized by interacting fire and grazing disturbance and oil and gas infrastructure. We found that Greater Prairie-Chicken survival was most affected by weather variability (expressed in our models as solar radiation) while most other variables had little influence. Focal disturbance did not affect survival directly, but vegetation height, which is greatly influenced by fire and grazing processes, was positively associated with nest survival. Greater Prairie-Chickens chose nesting locations that maximized time post fire while minimizing tree cover and distance to leks. Future conservation efforts for Greater Prairie-Chickens should focus on variable fire regimens that create areas of residual biomass to increase vegetation height and potentially reduce the effects of solar radiation while decreasing woody vegetation that is avoided by nesting females. However, even the best management practices may prove to be futile in the southern Great Plains if climate change continues to create unfavorable nest survival conditions. Management that creates and maintains suitable nesting sites through the use of interacting fire and grazing should maximize the potential for high reproduction in years when local weather variables are favorable. © 2015 Society for Range Management. Published by Elsevier Inc. All rights reserved.
    • An alternative rangeland management strategy in an agro-pastoral area in Western China

      Hua, L.; Yang, S.; Squires, V.; Wang, G. (Society for Range Management, 2015-03)
      Governance plays a key role in rangeland management. In China, all rangeland, including pastoral land and agro-pastoral land, is owned by the State. Since 1980, use rights have been granted to households by the Chinese government extending the household contract responsibility system (HCRS). But in the agro-pastoral areas of northwestern (NW) China, the rangeland degradation is more severe than that in pastoral areas. The HCRS is difficult to implement because the limited and fragmented grazing land cannot be contracted to individual households. Thus the pastures in the agro-pastoral areas are grazed as communal pastoral land and the rate of rangeland degradation has accelerated as livestock numbers have grown. Several measures have been introduced in an attempt to reverse this degradation trend, but most failed. This paper reports a 5-year comparison of three rangeland management regimens, including the national "Protecting rangeland by restricting grazing" (PRRG) project under the individual HCRS (PRRG under IHCRS), the Allied Householders Contract Responsibility System (AHCRS) program funded by the World Bank/GEF, and the free grazing on common pasture as the control area (CA) at Mayinggou Village, Yongchang County, Gansu Province in NW China. The results showed significant differences (P < 0.05) between AHCRS and the other two regimens (PRRG under IHCRS and CA) in terms of biomass of palatable forages, cover, and plant diversity index of vegetation but no significant difference (P > 0.05) between PRRG under IHCRS and CA. Reducing the number of livestock in AHCRS also resulted in increased revenue from the livestock turn-off rate compared with that in PRRG under IHCRS and CA. Therefore, AHCRS is a better alternative management regimen for rangelands in agro-pastoral areas. AHCRS can solve the overgrazing problem, maintain or improve household income, and potentially ensure a long-term sustainable rangeland management regimen in agro-pastoral areas in NW China. © 2015 Society for Range Management. Published by Elsevier Inc. All rights reserved.
    • Long-term forage and cow-calf performance and economic considerations of two stocking levels on chihuahuan desert rangeland

      Thomas, M. G.; Mohamed, A. H.; Sawalhah, M. N.; Holechek, J. L.; Bailey, D. W.; Hawkes, J. M.; Luna-Nevarez, P.; Molinar, F.; Khumalo, G. (Society for Range Management, 2015-03)
      Forage and cow-calf productivity on two lightly and two conservatively grazed pastures were evaluated over a 15-year period (1997-2011) in the Chihuahuan Desert of south-central New Mexico. Spring-calving Brangus cows were randomly assigned to pastures in January of each year. Pastures were similar in area (1 098 ± 69 ha, mean ± SE) with similar terrain and distance to water. Utilization of primary forage species averaged 27.1 ± 3.0% in lightly stocked pastures and 39.4 ± 4.0% on conservatively stocked pastures. No differences in perennial grass standing crop (163.5 ± 52.2 kg·ha-1) and calf weaning weights (286.1 ± 2.6 kg) were detected (P &gt; 0.10) between light and conservative treatments. Lightly grazed pastures yielded greater (P &lt; 0.05) kg of calf weaned·ha-1 and calf crop percent than conservatively grazed pastures in 1998 due to complete destocking of conservatively grazed pastures during that slight drought (i.e., rainfall was 75% of normal in 1998). After the initial 5 years of study (1997-2001), all pastures were destocked for 4 years (2002-2005) due to drought as rainfall was only 50% or less of normal. Pastures were then restocked for another 6 years (2006-2011). Postdrought, the percentage change in perennial grass standing forage crop (kg·ha-1) was -4.0 and -14.4 ± 2.5 % (P &lt; 0.09) in the light and conservative grazed pastures across the 6 years, respectively. While conservative stocking rates may provide higher net financial returns than light stocking rates during nondrought years as there were more AU per pasture, potential losses from cattle liquidation during short-term (i.e., 1-year) droughts could nullify this advantage. Results suggest that light grazing use of forage is a practical approach for Chihuahuan Desert cow-calf operations to minimize risk of herd liquidation during short-term drought. © 2015 Society for Range Management. Published by Elsevier Inc. All rights reserved.
    • Generation of ecosystem hotspots using short-term cattle corrals in an African savanna

      Porensky, L. M.; Veblen, K. E. (Society for Range Management, 2015-03)
      Worldwide, many rangelands are managed for multiple uses, and it is increasingly important to identify livestock management practices that maximize rangeland productivity, biodiversity, and wildlife conservation. In sub-Saharan Africa, pastoralists and ranchers use temporary thorn-fence corrals ("bomas") to protect livestock at night. Traditional boma sites (used for months or years, then abandoned) develop into productive ecosystem hotspots ("glades") that attract diverse wildlife and persist for decades or even centuries. In central Kenya, livestock managers have recently begun using metal-fenced "mobile bomas," which are moved after only days or weeks. Although the assumption is that mobile boma sites will also develop into glades, whether or not this is true remains unclear. We used a broad-scale manipulative experiment to evaluate the ecosystem-level effects of mobile bomas used for 1 month. We also investigated impacts of initial boma density on glade development. We randomly assigned 12 plots to one of three density treatments: one boma, two bomas 200 m apart, or two bomas 100 m apart. Before the experiment and at 1, 6, 12, 18, and 32 months after boma abandonment, we sampled soil nutrients, foliar nutrients, plant communities, and wildlife use (via dung counts) within abandoned boma sites (experimental glades) and at paired reference sites (200 m away). After 18 months, surface soil nutrient concentrations in experimental glades were similar to those in traditionally formed glades. Experimental glade plant communities became dominated by a palatable, rhizomatous grass species, Cynodon plectostachyus. After 32 months, wildlife use by browsing and mixed feeding ungulates was 9 times higher in experimental glades than at paired reference sites. Boma density had few impacts on within-glade development patterns. These results demonstrate that by concentrating livestock in short-term corrals, managers can create ecosystem hotspots that increase functional heterogeneity, attract wildlife, and provide palatable forage for livestock. © 2015 Society for Range Management. Published by Elsevier Inc. All rights reserved.
    • A survey-based assessment of cattle producers' adaptation to climate change in British Columbia, Canada

      Cox, M.; Gardner, W. C.; Fraser, L. H. (Society for Range Management, 2015-03)
      A quantitative analysis of the British Columbia, Canada cattle ranching community in light of global climate change provides insight as to how stakeholder needs and observations can be included in future planning. More than 63% of the 239 survey respondents believe that human activities are increasing the rate at which global climate changes occur, and 60% of 231 respondents adapted their management because of climate change. Cattle ranchers operating for less than 20 years were more likely to agree that human activities are increasing the rate of global climate change compared with those operating more than 40 years. This may reflect the fact that the concept of climate change has gained more public acceptance in the past 2 decades and would likely be perceived as a legitimate risk to an operation by those in this category in comparison with those who have been operating for a long period of time and tend to rely on experiential or embedded knowledge. Regional analysis showed that the most northerly region is more likely to have noticed change in climate compared with one of the most southern regions. With respect to operation of scale in terms of head of cattle, those ranches with more than 50 head of cattle identified water availability as a significant challenge to operations. Family succession planning was identified as a greater challenge for those operating their ranch for more than 40 years, compared with those operating less than 20 years. Adaptation to climate change included accessing available forage and providing a water source for cattle. Experiential and scientific knowledge will be crucial to future planning to reduce the vulnerability of the ranching industry and building adaptive capacity. © 2015 Society for Range Management. Published by Elsevier Inc. All rights reserved.