WorldWideScience

Sample records for grazed mixed prairies

  1. An experimental analysis of grasshopper community responses to fire and livestock grazing in a northern mixed-grass prairie.

    Science.gov (United States)

    Branson, David H; Sword, Gregory A

    2010-10-01

    The outcomes of grasshopper responses to both vertebrate grazing and fire vary across grassland ecosystems, and are strongly influenced by local climactic factors. Thus, the possible application of grazing and fire as components of an ecologically based grasshopper management strategy must be investigated in regional studies. In this study, we examined the effects of grazing and fire on grasshopper population density and community composition in a northern Great Plains mixed-grass prairie. We employed a large-scale, replicated, and fully-factorial manipulative experimental design across 4 yr to examine the separate and interactive effects of three grazing systems in burned and unburned habitats. Grasshopper densities were low throughout the 4-yr study and 1 yr of pretreatment sampling. There was a significant fire by grazing interaction effect on cumulative density and community composition, resulting from burned season long grazing pastures having higher densities than unburned pastures. Shannon diversity and grasshopper species richness were significantly higher with twice-over rotational livestock grazing. The ability to draw strong conclusions regarding the nature of species composition shifts and population changes in the presence of fire and grazing is complicated by the large site differences and low grasshopper densities. The results reinforce the importance of long-term research to examine the effects of habitat manipulation on grasshopper population dynamics.

  2. Flora and fauna associated with prairie dog colonies and adjacent ungrazed mixed-grass prairie in western South Dakota

    Science.gov (United States)

    William Agnew; Daniel W. Uresk; Richard M. Hansen

    1986-01-01

    Vegetation, small rodents, and birds were sampled during the growing seasons of 2 years on prairie dog (Cynomys ludovicianus) colonies and adjacent mixed-grass prairie in western South Dakota. Prairie dog grazing decreased mulch cover, maximum height of vegetation, plant species richness, and tended to decrease live plant canopy cover compared to...

  3. Butterfly responses to prairie restoration through fire and grazing

    Science.gov (United States)

    Vogel, Jennifer A.; Debinski, Diane M.; Koford, Rolf R.; Miller, J.R.

    2007-01-01

    The development of land for modern agriculture has resulted in losses of native prairie habitat. The small, isolated patches of prairie habitat that remain are threatened by fire suppression, overgrazing, and invasion by non-native species. We evaluated the effects of three restoration practices (grazing only, burning only, and burning and grazing) on the vegetation characteristics and butterfly communities of remnant prairies. Total butterfly abundance was highest on prairies that were managed with burning and grazing and lowest on those that were only burned. Butterfly species richness did not differ among any of the restoration practices. Butterfly species diversity was highest on sites that were only burned. Responses of individual butterfly species to restoration practices were highly variable. In the best predictive regression model, total butterfly abundance was negatively associated with the percent cover of bare ground and positively associated with the percent cover of forbs. Canonical correspondence analysis revealed that sites with burned only and grazed only practices could be separated based on their butterfly community composition. Butterfly communities in each of the three restoration practices are equally species rich but different practices yield compositionally different butterfly communities. Because of this variation in butterfly species responses to different restoration practices, there is no single practice that will benefit all species or even all species within habitat-specialist or habitat-generalist habitat guilds. ?? 2007 Elsevier Ltd. All rights reserved.

  4. The influence of grazing on surface climatological variables of tallgrass prairie. Final Technical Report

    International Nuclear Information System (INIS)

    Seastedt, T.R.; Dyer, M.I.; Turner, C.L.

    1992-01-01

    Mass and energy exchange between most grassland canopies and the atmosphere are mediated by grazing activities. Ambient temperatures can be increased or decreased by grazers. Data have been assembled from simulated grazing experiments on Konza Prairie Research Natural Area and observations on adjacent pastures grazed by cattle show significant changes in primary production, nutrient content, and bidirectional reflectance characteristics as a function of grazing intensity. The purpose of this research was to provide algorithms that would allow incorporation of grazing effects into models of energy budgets using remote sensing procedures. The approach involved: (1) linking empirical measurements of plant biomass and grazing intensities to remotely sensed canopy reflectance, and (2) using a higher resolution, mechanistic grazing model to derive plant ecophysiological parameters that influence reflectance and other surface climatological variables

  5. Restoring sand shinnery oak prairies with herbicide and grazing in New Mexico

    Science.gov (United States)

    Zavaleta, Jennifer C.; Haukos, David A.; Grisham, Blake A.; Boal, Clint W.; Dixon, Charles

    2016-01-01

    Sand shinnery oak (Quercus havardii) prairies are increasingly disappearing and increasingly degraded in the Southern High Plains of Texas and New Mexico. Restoring and managing sand shinnery oak prairie can support biodiversity, specific species of conservation concern, and livestock production. We measured vegetation response to four treatment combinations of herbicide (tebuthiuron applied at 0.60 kg/ha) and moderate-intensity grazing (50% removal of annual herbaceous production) over a 10-year period in a sand shinnery oak prairie of eastern New Mexico. We compared the annual vegetation response to the historical climax plant community (HCPC) as outlined by the U.S. Department of Agriculture Ecological Site Description. From 2 to 10 years postapplication, tebuthiuron-treated plots had reduced shrub cover with twice as much forb and grass cover as untreated plots. Tebuthiuron-treated plots, regardless of the presence of grazing, most frequently met HCPC. Tebuthiuron and moderate-intensity grazing increased vegetation heterogeneity and, based on comparison of the HCPC, successfully restored sand shinnery oak prairie to a vegetation composition similar to presettlement.

  6. Grasshopper fecundity responses to grazing and fire in a tallgrass prairie.

    Science.gov (United States)

    Laws, Angela N; Joern, Anthony

    2011-10-01

    Grasshopper abundance and diversity vary with management practices such as fire and grazing. Understanding how grasshopper life history traits such as fecundity respond to management practices is key to predicting grasshopper population dynamics in heterogeneous environments. Landscape-level experimental fire and bison grazing treatments at the Konza Prairie Biological Station (Manhattan, KS) provide an opportunity to examine how management affects grasshopper fecundity. Here we report on grasshopper fecundity for nine common species at Konza Prairie. From 2007 to 2009, adult female grasshoppers were collected every 3 wk from eight watersheds that varied in fire and grazing treatments. Fecundity was measured by examining female reproductive tracts, which contain a record of past and current reproductive activity. Body size was a poor predictor of fecundity for all species. Despite large differences in vegetation structure and composition with management regime (grazing and fire interval), we observed little effect of management on grasshopper fecundity. Habitat characteristics (grasshopper density, vegetation biomass, and vegetation quality; measured in 2008 and 2009) were better predictors of past fecundity than current fecundity, with species-specific responses. Fecundity increased throughout the summer, indicating that grasshoppers were able to acquire sufficient nutritional resources for egg production in the early fall when vegetation quality is generally low. Because fecundity did not vary across management treatments, population stage structure may be more important for determining population level reproduction than management regime at Konza Prairie.

  7. Arthropod consumption by small mammals on prairie dog colonies and adjacent ungrazed mixed grass prairie in western South Dakota

    Science.gov (United States)

    W. Agnew; Daniel W. Uresk; R. M. Hansen

    1988-01-01

    The percentage of arthropods and plants in the diets of seven small rodents captured on prairie dog colonies and adjacent mixed grasslands were estimated by microhistological techniques. Arthropod composition over the two year study averaged 51% and 37% on prairie dog colonies and mixed grasslands, respectively. Composition of arthropods on prairie dog colonies was...

  8. Effects of Grazing and Fire Frequency on Floristic Quality and its Relationship to Indicators of Soil Quality in Tallgrass Prairie.

    Science.gov (United States)

    Manning, George C; Baer, Sara G; Blair, John M

    2017-12-01

    Fire and grazing are widely used to manage grasslands for conservation purposes, but few studies have evaluated the effects of these drivers on the conservation value of plant communities measured by the floristic quality index (FQI). Further, the influence of fire and grazing on soil properties and functions are difficult for land managers and restoration practitioners to assess. The objectives of this study were to: (1) quantify the independent and interactive effects of grazing and fire frequency on floristic quality in native tallgrass prairie to provide potential benchmarks for community assessment, and (2) to explore whether floristic quality can serve as an indicator of soil structure and function for more holistic ecosystem assessments. A factorial combination of fire frequencies (1-2, 4, and 20 years return intervals) and grazing (by bison or ungrazed) treatments were sampled for plant species composition, and for several indicators of soil quality in lowland tallgrass prairie. Floristic quality, diversity, and richness were higher in grazed than ungrazed prairie over all fire frequencies (P soil bulk density were also higher in grazed prairie soil over all fire frequencies (P soil N were positively correlated with FQI (P soil N pools are more strongly influenced by grazing than fire and that floristic quality can be an indicator of total soil C and N stocks in never cultivated lowland prairie.

  9. Effects of Grazing and Fire Frequency on Floristic Quality and its Relationship to Indicators of Soil Quality in Tallgrass Prairie

    Science.gov (United States)

    Manning, George C.; Baer, Sara G.; Blair, John M.

    2017-12-01

    Fire and grazing are widely used to manage grasslands for conservation purposes, but few studies have evaluated the effects of these drivers on the conservation value of plant communities measured by the floristic quality index (FQI). Further, the influence of fire and grazing on soil properties and functions are difficult for land managers and restoration practitioners to assess. The objectives of this study were to: (1) quantify the independent and interactive effects of grazing and fire frequency on floristic quality in native tallgrass prairie to provide potential benchmarks for community assessment, and (2) to explore whether floristic quality can serve as an indicator of soil structure and function for more holistic ecosystem assessments. A factorial combination of fire frequencies (1-2, 4, and 20 years return intervals) and grazing (by bison or ungrazed) treatments were sampled for plant species composition, and for several indicators of soil quality in lowland tallgrass prairie. Floristic quality, diversity, and richness were higher in grazed than ungrazed prairie over all fire frequencies ( P total N, and soil bulk density were also higher in grazed prairie soil over all fire frequencies ( P total organic C, and total soil N were positively correlated with FQI ( P quality and soil N pools are more strongly influenced by grazing than fire and that floristic quality can be an indicator of total soil C and N stocks in never cultivated lowland prairie.

  10. Nest Success and Cause-Specific Nest Failure of Grassland Passerines Breeding in Prairie Grazed by Livestock

    Science.gov (United States)

    This manuscript describes two years of field research on ground-nesting songbird species at Zumwalt Prairie Reserve, northeastern Oregon, USA. Cattle-grazing has long been suspected in declines of ground-nesting songbirds in grazed grassland, primarily due to increased trampling...

  11. Bison grazing increases arthropod abundance and diversity in a tallgrass prairie.

    Science.gov (United States)

    Moran, Matthew D

    2014-10-01

    How grazing-induced ecosystem changes by ungulates indirectly affect other consumers is a question of great interest. I investigated the effect of grazing by American Bison (Bos bison L.) on an arthropod community in tallgrass prairie. Grazing increased the abundance of arthropods, an increase that was present in both herbivorous and carnivorous assemblages, but not in detritivores. The increase in herbivores and reduction in plant biomass from grazing resulted in an arthropod herbivore load almost three times higher in grazed plots compared with controls. Among herbivores, the sap-feeding insect guild was dramatically more abundant, while chewing herbivores were not affected. Herbivorous and carnivorous arthropod richness was higher in grazed plots, although the response was strongest among herbivores. Arthropod abundance on individual grasses and forbs was significantly higher in grazed areas, while plant type had no effect on abundance, indicating that the change was ecosystem-wide and not simply in response to a reduction in grass biomass from grazing. The response of arthropods to grazing was strongest in the early part of the growing season. Published research shows that ungulate grazing, although decreasing available biomass to other consumers, enhances plant quality by increasing nitrogen level in plants. The arthropod results of this study suggest higher plant quality outweighs the potential negative competitive effects of plant biomass removal, although other activities of bison could not be ruled out as the causative mechanism. Because arthropods are extremely abundant organisms in grasslands and a food source for other consumers, bison may represent valuable management tools for maintaining biodiversity.

  12. Use of ecological sites in managing wildlife and livestock: An example with prairie dogs

    Science.gov (United States)

    Prairie dogs are a native rodent found in the mixed grass prairie of the northern Great Plains. Prairie dogs can have an adverse impact on the amount of forages available for grazing livestock. In the Native American community, prairie dogs are often valued as a cultural resource and as an importan...

  13. Mixed farming in a grazing reserve in Northern Nigeria | Babalobi ...

    African Journals Online (AJOL)

    Nigeria's main pastoral development strategy is the settlement of pastoralists in grazing reserves. The goal of the strategy is to turn such nomadic pastoralists into mixed farmers who will take up crop farming to supplement livestock farming. Using the Bobi Grazing Reserve, Niger State, Nigeria as case study, the attainment ...

  14. Mixed grazing systems benefit both upland biodiversity and livestock production.

    Directory of Open Access Journals (Sweden)

    Mariecia D Fraser

    Full Text Available With world food demand expected to double by 2050, identifying farming systems that benefit both agricultural production and biodiversity is a fundamentally important challenge for the 21(st century, but this has to be achieved in a sustainable way. Livestock grazing management directly influences both economic outputs and biodiversity on upland farms while contributing to potentially damaging greenhouse gas emissions, yet no study has attempted to address these impacts simultaneously.Using a replicated, landscape-scale field experiment consisting of five management 'systems' we tested the effects of progressively altering elements within an upland farming system, viz i incorporating cattle grazing into an upland sheep system, ii integrating grazing of semi-natural rough grazing into a mixed grazing system based on improved pasture, iii altering the stocking ratio within a mixed grazing system, and iv replacing modern crossbred cattle with a traditional breed. We quantified the impacts on livestock productivity and numbers of birds and butterflies over four years.We found that management systems incorporating mixed grazing with cattle improve livestock productivity and reduce methane emissions relative to sheep only systems. Systems that also included semi-natural rough grazing consistently supported more species of birds and butterflies, and it was possible to incorporate bouts of summer grazing of these pastures by cattle to meet habitat management prescriptions without compromising cattle performance overall. We found no evidence that the system incorporating a cattle breed popular as a conservation grazer was any better for bird and butterfly species richness than those based on a mainstream breed, yet methane emissions from such a system were predicted to be higher. We have demonstrated that mixed upland grazing systems not only improve livestock production, but also benefit biodiversity, suggesting a 'win-win' solution for farmers and

  15. Linking phenology and biomass productivity in South Dakota mixed-grass prairie

    Science.gov (United States)

    Rigge, Matthew; Smart, Alexander; Wylie, Bruce; Gilmanov, Tagir; Johnson, Patricia

    2013-01-01

    Assessing the health of rangeland ecosystems based solely on annual biomass production does not fully describe plant community condition; the phenology of production can provide inferences on species composition, successional stage, and grazing impacts. We evaluate the productivity and phenology of western South Dakota mixed-grass prairie using 2000 to 2008 Moderate Resolution Imaging Spectrometer (MODIS) normalized difference vegetation index (NDVI) satellite imagery at 250 m spatial resolution. Growing season NDVI images were integrated weekly to produce time-integrated NDVI (TIN), a proxy of total annual biomass production, and integrated seasonally to represent annual production by cool (C3) and warm (C4) season species. Additionally, a variety of phenological indicators including cool season percentage of TIN were derived from the seasonal profiles of NDVI. Cool season percentage and TIN were combined to generate vegetation classes, which served as proxies of plant community condition. TIN decreased with precipitation from east to west across the study area. Alternatively, cool season percentage increased from east to west, following patterns related to the reliability (interannual coefficient of variation [CV]) and quantity of mid-summer precipitation. Cool season TIN averaged 76.8% of total. Seasonal accumulation of TIN corresponded closely (R2 > 0.90) to that of gross photosynthesis data from a carbon flux tower. Field-collected biomass and community composition data were strongly related to the TIN and cool season percentage products. The patterns of vegetation classes were responsive to topographic, edaphic, and land management influences on plant communities. Accurate maps of biomass production, cool/warm season composition, and vegetation classes can improve the efficiency of land management by adjusting stocking rates and season of use to maximize rangeland productivity and achieve conservation objectives. Further, our results clarify the spatial and

  16. Greenhouse gas fluxes of grazed and hayed wetland catchments in the U.S. Prairie Pothole Ecoregion

    Science.gov (United States)

    Finocchiaro, Raymond G.; Tangen, Brian A.; Gleason, Robert A.

    2014-01-01

    Wetland catchments are major ecosystems in the Prairie Pothole Region (PPR) and play an important role in greenhouse gases (GHG) flux. However, there is limited information regarding effects of land-use on GHG fluxes from these wetland systems. We examined the effects of grazing and haying, two common land-use practices in the region, on GHG fluxes from wetland catchments during 2007 and 2008. Fluxes of methane (CH4), nitrous oxide (N2O), and carbon dioxide (CO2), along with soil water content and temperature, were measured along a topographic gradient every other week during the growing season near Ipswich, SD, USA. Closed, opaque chambers were used to measure fluxes of soil and plant respiration from native sod catchments that were grazed or left idle, and from recently restored catchments which were seeded with native plant species; half of these catchments were hayed once during the growing season. Catchments were adjacent to each other and had similar soils, soil nitrogen and organic carbon content, precipitation, and vegetation. When compared with idle catchments, grazing as a land-use had little effect on GHG fluxes. Likewise, haying had little effect on fluxes of CH4 and N2O compared with non-hayed catchments. Haying, however, did have a significant effect on combined soil and vegetative CO2 flux in restored wetland catchments owing to the immediate and comprehensive effect haying has on plant productivity. This study also examined soil conditions that affect GHG fluxes and provides cumulative annual estimates of GHG fluxes from wetland catchment in the PPR.

  17. Map of mixed prairie grassland vegetation, Rocky Flats, Colorado

    Energy Technology Data Exchange (ETDEWEB)

    Clark, S J.V.; Webber, P J; Komarkova, V; Weber, W A

    1980-01-01

    A color vegetation map at the scale of 1:12,000 of the area surrounding the Rocky Flats, Rockwell International Plant near Boulder, Colorado, provides a permanent record of baseline data which can be used to monitor changes in both vegetation and environment and thus to contribute to future land management and land-use policies. Sixteen mapping units based on species composition were identified, and characterized by two 10-m/sup 2/ vegetation stands each. These were grouped into prairie, pasture, and valley side on the basis of their species composition. Both the mapping units and these major groups were later confirmed by agglomerative clustering analysis of the 32 vegetation stands on the basis of species composition. A modified Bray and Curtis ordination was used to determine the environmental factor complexes controlling the distribution of vegetation at Rocky flats. Recommendations are made for future policies of environmental management and predictions of the response to environmental change of the present vegetation at the Rocky Flats site.

  18. forage systems mixed with forage legumes grazed by lactating cows

    Directory of Open Access Journals (Sweden)

    Clair Jorge Olivo

    2017-02-01

    Full Text Available Current research evaluates productivity, stocking and nutritional rates of three forage systems with Elephant Grass (EG + Italian Ryegrass (IR + Spontaneous Growth Species (SGS, without forage legumes; EG + IR + SGS + Forage Peanut (FP, mixed with FP; and EG + IR + SGS + Red Clover (RC, mixed with RC, in rotational grazing method by lactating cows. IR developed between rows of EG. FP was maintained, whilst RC was sow to respective forage systems. The experimental design was completely randomized, with three treatments and two replication, subdivided into parcels over time. Mean rate for forage yield and average stocking rate were 10.6, 11.6 and 14.4 t ha-1; 3.0, 2.8 and 3.1 animal unit ha-1 day-1, for the respective systems. Levels of crude protein and total digestible nutrients were 17.8, 18.7 and 17.5%; 66.5, 66.8 and 64.8%, for the respective forage systems. The presence of RC results in better and higher forage yield in the mixture, whilst FP results in greater control of SGS. The inclusion of forage legumes in pasture systems provides better nutritional rates.

  19. Effect of frame size and season on enteric methane (CH4) and carbon dioxide (CO2)emissions in Angus brood cows grazing native tall-grass prairie in central Oklahoma USA

    Science.gov (United States)

    Effect of frame size and season on enteric methane (CH4) and carbon dioxide (CO2) emissions in Angus brood cows grazing native tall-grass prairie in central Oklahoma, USA J.P.S. Neel USDA ARS, El Reno, OK A reduction in enteric CH4 production in ruminants is associated with improved production effic...

  20. Ecosystem engineering varies spatially: a test of the vegetation modification paradigm for prairie dogs

    Science.gov (United States)

    Baker, Bruce W.; Augustine, David J.; Sedgwick, James A.; Lubow, Bruce C.

    2013-01-01

    Colonial, burrowing herbivores can be engineers of grassland and shrubland ecosystems worldwide. Spatial variation in landscapes suggests caution when extrapolating single-place studies of single species, but lack of data and the need to generalize often leads to ‘model system’ thinking and application of results beyond appropriate statistical inference. Generalizations about the engineering effects of prairie dogs (Cynomys sp.) developed largely from intensive study at a single complex of black-tailed prairie dogs C. ludovicianus in northern mixed prairie, but have been extrapolated to other ecoregions and prairie dog species in North America, and other colonial, burrowing herbivores. We tested the paradigm that prairie dogs decrease vegetation volume and the cover of grasses and tall shrubs, and increase bare ground and forb cover. We sampled vegetation on and off 279 colonies at 13 complexes of 3 prairie dog species widely distributed across 5 ecoregions in North America. The paradigm was generally supported at 7 black-tailed prairie dog complexes in northern mixed prairie, where vegetation volume, grass cover, and tall shrub cover were lower, and bare ground and forb cover were higher, on colonies than at paired off-colony sites. Outside the northern mixed prairie, all 3 prairie dog species consistently reduced vegetation volume, but their effects on cover of plant functional groups varied with prairie dog species and the grazing tolerance of dominant perennial grasses. White-tailed prairie dogs C. leucurus in sagebrush steppe did not reduce shrub cover, whereas black-tailed prairie dogs suppressed shrub cover at all complexes with tall shrubs in the surrounding habitat matrix. Black-tailed prairie dogs in shortgrass steppe and Gunnison's prairie dogs C. gunnisoni in Colorado Plateau grassland both had relatively minor effects on grass cover, which may reflect the dominance of grazing-tolerant shortgrasses at both complexes. Variation in modification of

  1. Modeling the influence from ocean transport, mixing and grazing on phytoplankton diversity

    DEFF Research Database (Denmark)

    Adjou, Mohamed; Bendtsen, Jørgen; Richardson, Katherine

    2012-01-01

    Phytoplankton diversity, whether defined on the basis of functional groups or on the basis of numbers of individual species, is known to be heterogeneous throughout the global ocean. The factors regulating this diversity are generally poorly understood, although access to limiting nutrients...... in generating and maintaining diversity, we apply the model to quantify the potential role of zooplankton grazing and ocean transport for the coexistence of competing species and phytoplankton diversity. We analyze the sensitivity of phytoplankton biomass distributions to different types of grazing functional...... responses and show that preferential grazing on abundant species, for example as formulated by the Holling type III grazing function, is a key factor for maintaining species’ coexistence. Mixing and large-scale advection are shown to potentially have a significant impact on the distribution of phytoplankton...

  2. Ducks and passerines nesting in northern mixed-grass prairie treated with fire

    Science.gov (United States)

    Grant, Todd A.; Shaffer, Terry L.; Madden, Elizabeth M.; Berkey, Gordon B.

    2011-01-01

    Prescribed fire is an important, ecology-driven tool for restoration of grassland systems. However, prescribed fire remains controversial for some grassland managers because of reported reductions in bird use of recently burned grasslands. Few studies have evaluated effects of fire on grassland bird populations in the northern mixed-grass prairie region. Fewer studies yet have examined the influence of fire on nest density or survival. In our review, we found no studies that simultaneously examined effects of fire on duck and passerine nesting. During 1998—2003, we examined effects of prescribed fire on the density of upland-nesting ducks and passerines nesting in north-central North Dakota, USA. Apparent nest densities of gadwall (Anas strepera), mallard (A. platyrhynchos), and all duck species combined, were influenced by fire history of study units, although the degree of influence was not compelling. Fire history was not related to nest densities of blue-winged teal (A. discors), northern shoveler (A. clypeata), or northern pintail (A. acuta); however, apparent nest densities in relation to the number of postfire growing seasons exhibited a strikingly similar pattern among all duck species. When compared to ducks, fire history strongly influenced apparent nest densities of clay-colored sparrow (Spizella pallida), Savannah sparrow (Passerculus sandwichensis), and bobolink (Dolichonyx oryzivorus). For most species examined, apparent nest densities were lowest in recently burned units, increased during the second postfire growing season, and stabilized or, in some cases, decreased thereafter. Prescribed fire is critical for restoring the ecology of northern mixed-grass prairies and our findings indicate that reductions in nest densities are limited mostly to the first growing season after fire. Our results support the premise that upland-nesting ducks and several grassland passerine species are adapted to periodic fires occurring at a frequency similar to that

  3. Herbage intake of dairy cows in mixed sequential grazing with breeding ewes as followers.

    Science.gov (United States)

    Jiménez-Rosales, Juan Daniel; Améndola-Massiotti, Ricardo Daniel; Burgueño-Ferreira, Juan Andrés; Ramírez-Valverde, Rodolfo; Topete-Pelayo, Pedro; Huerta-Bravo, Maximino

    2018-03-01

    This study aimed to evaluate the hypothesis that mixed sequential grazing of dairy cows and breeding ewes is beneficial. During the seasons of spring-summer 2013 and autumn-winter 2013-2014, 12 (spring-summer) and 16 (autumn-winter) Holstein Friesian cows and 24 gestating (spring-summer) and lactating (autumn-winter) Pelibuey ewes grazed on six (spring-summer) and nine (autumn-winter) paddocks of alfalfa and orchard grass mixed pastures. The treatments "single species cow grazing" (CowG) and "mixed sequential grazing with ewes as followers of cows" (MixG) were evaluated, under a completely randomized design with two replicates per paddock. Herbage mass on offer (HO) and residual herbage mass (RH) were estimated by cutting samples. The estimate of herbage intake (HI) of cows was based on the use of internal and external markers; the apparent HI of ewes was calculated as the difference between HO (RH of cows) and RH. Even though HO was higher in CowG, the HI of cows was higher in MixG during spring-summer and similar in both treatments during autumn-winter, implying that in MixG the effects on the cows HI of higher alfalfa proportion and herbage accumulation rate evolving from lower residual herbage mass in the previous cycle counteracted that of a higher HO in CowG. The HI of ewes was sufficient to enable satisfactory performance as breeding ewes. Thus, the benefits of mixed sequential grazing arose from higher herbage accumulation, positive changes in botanical composition, and the achievement of sheep production without negative effects on the herbage intake of cows.

  4. PRODUCTIVITY OF A SILVOPASTORAL SYSTEM UNDER INTENSIVE MIXED SPECIES GRAZING BY CATTLE AND SHEEP

    Directory of Open Access Journals (Sweden)

    Leonor Yalid Manriquez-Mendoza

    2011-11-01

    Full Text Available The presence of forage trees in pastures enhances yield and nutritional quality of forage available for animal feeding. We assessed forage yield and nutritional quality, and weight gain of cattle and sheep foraging in a silvopastoral system containing Guazuma ulmifolia Lam. and the grasses Digitaria eriantha Stent (cv. Pangola, Brachiaria brizantha (Hochst. ex A. Rich. Stapf (cv. Insurgentes and Megathyrsus maximus (Jacq. B.K. Simon & S.W.L. Jacobs (cv. Tanzania, during three seasons (windy, dry and rainy in two grazing treatments: 1 mixed species grazing by four to five Criollo Lechero Tropical heifers and six female Pelibuey lambs, and 2 simple species grazing by 12 female Pelibuey lambs. Weight gain was greater (P

  5. Characterization of ion-beam mixed multilayers via grazing x-ray reflectometry

    International Nuclear Information System (INIS)

    Le Boite, M.G.; Traverse, A.; Nevot, L.; Pardo, B.; Corno, J.

    1988-01-01

    The grazing x-ray reflectrometry technique was used as a way to study modifications in metallic multilayers induced by ion-beam irradiation. Due to the high sensitivity of the technique, short-range atomic displacements of an atom A in a layer B can be detected so that the first stages of ion-beam mixing can be investigated. The rate of mixing is measured and the compound A/sub 1-//sub x/B/sub x/ formed at the layers' interfaces is characterized

  6. Alien plant invasion in mixed-grass prairie: Effects of vegetation type and anthropogenic disturbance

    Science.gov (United States)

    Larson, D.L.; Anderson, P.J.; Newton, W.

    2001-01-01

    The ability of alien plant species to invade a region depends not only on attributes of the plant, but on characteristics of the habitat being invaded. Here, we examine characteristics that may influence the success of alien plant invasion in mixed-grass prairie at Theodore Roosevelt National Park, in western North Dakota, USA. The park consists of two geographically separate units with similar vegetation types and management history, which allowed us to examine the effects of native vegetation type, anthropogenic disturbance, and the separate park units on the invasion of native plant communities by alien plant species common to counties surrounding both park units. If matters of chance related to availability of propagules and transient establishment opportunities determine the success of invasion, park unit and anthropogenic disturbance should better explain the variation in alien plant frequency. If invasibility is more strongly related to biotic or physical characteristics of the native plant communities, models of alien plant occurrence should include vegetation type as an explanatory variable. We examined >1300 transects across all vegetation types in both units of the park. Akaike's Information Criterion (AIC) indicated that the fully parameterized model, including the interaction among vegetation type, disturbance, and park unit, best described the distribution of both total number of alien plants per transect and frequency of alien plants on transects where they occurred. Although all vegetation types were invaded by alien plants, mesic communities had both greater numbers and higher frequencies of alien plants than did drier communities. A strong element of stochasticity, reflected in differences in frequencies of individual species between the two park units, suggests that prediction of risk of invasion will always involve uncertainty. In addition, despite well-documented associations between anthropogenic disturbance and alien plant invasion, five of

  7. Sparrow nest survival in relation to prescribed fire and woody plant invasion in a northern mixed-grass prairie

    Science.gov (United States)

    Murphy, Robert K.; Shaffer, Terry L.; Grant, Todd A.; Derrig, James L.; Rubin, Cory S.; Kerns, Courtney K.

    2017-01-01

    Prescribed fire is used to reverse invasion by woody vegetation on grasslands, but managers often are uncertain whether influences of shrub and tree reduction outweigh potential effects of fire on nest survival of grassland birds. During the 2001–2003 breeding seasons, we examined relationships of prescribed fire and woody vegetation to nest survival of clay-colored sparrow (Spizella pallida) and Savannah sparrow (Passerculus sandwichensis) in mixed-grass prairie at Des Lacs National Wildlife Refuge in northwestern North Dakota, USA. We assessed relationships of nest survival to 1) recent fire history, in terms of number of breeding seasons (2, 3, or 4–5) since the last prescribed fire, and 2) prevalence of trees and tall (>1.5 m) shrubs in the landscape and of low (≤1.5 m) shrubs within 5 m of nests. Nest survival of both species exhibited distinct patterns related to age of the nest and day of year, but bore no relationship to fire history. Survival of clay-colored sparrow nests declined as the amount of trees and tall shrubs within 100 m increased, but we found no relationship to suggest nest parasitism by brown-headed cowbirds (Molothrus ater) as an underlying mechanism. We found little evidence linking nest survival of Savannah sparrow to woody vegetation. Our results suggest that fire can be used to restore northern mixed-grass prairies without adversely affecting nest survival of ≥2 widespread passerine species. Survival of nests of clay-colored sparrow may increase when tall woody cover is reduced by fire. Our data lend support to the use of fire for reducing scattered patches of tall woody cover to enhance survival of nests of ≥1 grassland bird species in northern mixed-grass prairies, but further study is needed that incorporates experimental approaches and assessments of shorter term effects of fire on survival of nests of grassland passerines.

  8. Effects of prescribed burning and litter type on litter decomposition and nutrient release in mixed-grass prairie in Eastern Montana

    Science.gov (United States)

    Fire can affect litter decomposition and carbon (C) and nitrogen (N) dynamics. Here, we examined the effect of summer fire and three litter types on litter decomposition and litter C and N dynamics in a northern mixed-grass prairie over a 24 month period starting ca. 14 months after fire. Over all...

  9. Mixed grazing systems of goats with cattle in tropical conditions: an alternative to improving animal production in the pasture.

    Science.gov (United States)

    d'Alexis, S; Periacarpin, F; Jackson, F; Boval, M

    2014-08-01

    Mixed grazing systems combining sheep and cattle have shown better growth performance for one or both species. This observation has been attributed to their complementary feeding behaviour and the reduced host infection by gastrointestinal nematodes. Less attention has been paid to mixed grazing systems combining goats and cattle. Here, continuously grazing goats mixed with cattle (M) were compared with control goats reared alone (C) under tropical conditions. The comparison was conducted with gastrointestinal nematode-infected (I) and non-infected (nI) goats. Thus, the four treatments were cattle with gastrointestinal nematode-infected goats (MI), gastrointestinal nematode-infected goats alone (CI), cattle with non-infected goats (MnI) and non-infected goats (CnI). Average daily gain (ADG, g/day) and grass production were measured for the four groups of animals (six goats and two heifers treated with MI or MnI) grazing for 3 months on 4 subplots. Monthly measurements were performed over 5-day periods. This pattern was replicated in space for a second set of four subplots and in time for six successive cohorts of animals (bands 1 to 6). The ADG of goats in mixed grazing conditions was higher than controls irrespective of the infection status (32.6 v. 18.4 g/day for MI v. CI; 44.2 v. 33.5 g/day for MnI v. CnI). Concomitantly, the average biomass was lower for mixed grazing animals compared with controls (174 v. 170 for MI and MnI; 235 v. 208 for CI and CnI, respectively), suggesting better use of the sward. For daily BW gain (g/kg DM), mixed grazing also yielded better results than the control (1.88 v. 0.52 g BW/kg DM per day for MI v. CI; 2.08 v. 1.47 g BW/kg DM per day for MnI and CnI). Mixed grazing of goats and heifers offers a promising alternative for increasing goat and overall animal production as well as improving the management of pastures.

  10. Forage production in mixed grazing systems of elephant grass with arrowleaf clover or forage peanut

    Directory of Open Access Journals (Sweden)

    Daiane Cristine Seibt

    Full Text Available ABSTRACT Most dairy production systems are pasture-based, usually consisting of sole grass species. This system facilitates pasture management, but results in high production costs, mainly because of nitrogen fertilizers. An alternative to making forage systems more sustainable is to introduce legumes into the pasture. Mixed pastures allow better forage distribution over time and reduce fertilization costs. Thus, the objective of this study was to evaluate, throughout the year, three forage systems (FS: FS1 (control - elephant grass (EG, ryegrass (RG, and spontaneous species (SS; FS2 - EG + RG + SS + arrowleaf clover; and FS3 - EG + RG + SS + forage peanut. Elephant grass was planted in rows spaced 4 m apart. Ryegrass was sown between the EG lines, in the winter. Arrowleaf clover was sown according to the respective treatments and forage peanut was preserved. Evaluation was carried out using Holstein cows. The experiment was arranged in a completely randomized design, with three treatments (FS, and three repetitions (paddocks with repeated measurements (grazing cycles. Forage mass achieved 3.46, 3.80, and 3.91 t ha-1 for the treatments FS1, FS2 and FS3, respectively. The forage systems intercropped with legumes produced the best results.

  11. Bud-bank and tiller dynamics of co-occurring C3 caespitose grasses in mixed-grass prairie.

    Science.gov (United States)

    Ott, Jacqueline P; Hartnett, David C

    2015-09-01

    Tiller recruitment from the belowground bud bank of caespitose grasses influences their ability to monopolize local resources and, hence, their genet fitness. Differences in bud production and outgrowth among tiller types within a genet and among species may explain co-occurrence of caespitose grasses. This study aimed to characterize genet bud-bank and tiller production and dynamics in two co-occurring species and compare their vegetative reproductive strategies. Bud-bank and tiller dynamics of Hesperostipa comata and Nassella viridula, dominant C3 caespitose grasses in the northern mixed-grass prairie of North America, were assessed throughout an annual cycle. The two species showed similar strategies, maintaining polycyclic tillers and thus creating mixed-age genet bud banks comprising multiple bud cohorts produced in different years. Vegetative tillers produced the majority of buds, whereas flowering tillers contributed little to the bud bank. Buds lived for at least 2 yr and were maintained in multiple developmental stages throughout the year. Because bud longevity rarely exceeded tiller longevity, tiller longevity drove turnover within the bud bank. Tiller population dynamics, more than bud production per tiller, determined the differential contribution of tiller types to the bud bank. Nassella viridula had higher bud production per tiller, a consistent annual tiller recruitment density, and greater longevity of buds on senesced and flowering tillers than H. comata. Co-occurring C3 caespitose grasses had similar bud-bank and tiller dynamics contributing to genet persistence but differed in bud characteristics that could affect genet longevity and species coexistence. © 2015 Botanical Society of America.

  12. Alien plant invasion in mixed-grass prairie: effects of vegetation type, stochiasticity, and anthropogenic disturbance in two park units

    Science.gov (United States)

    Larson, Diane L.; Anderson, Patrick J.; Newton, Wesley E.

    2001-01-01

    The ability of alien plant species to invade a region depends not only on attributes of the plant, but on characteristics of the habitat being invaded. Here, we examine characteristics that may influence the success of alien plant invasion in mixed-grass prairie at Theodore Roosevelt National Park, in western North Dakota, USA. The park consists of two geographically separate units with similar vegetation types and management history, which allowed us to examine the effects of native vegetation type, anthropogenic disturbance, and the separate park units on the invasion of native plant communities by alien plant species common to counties surrounding both park units. If matters of chance related to availability of propagules and transient establishment opportunities determine the success of invasion, park unit and anthropogenic disturbance should better explain the variation in alien plant frequency. If invasibility is more strongly related to biotic or physical characteristics of the native plant communities, models of alien plant occurrence should include vegetation type as an explanatory variable. We examined >1300 transects across all vegetation types in both units of the park. Akaike's Information Criterion (AIC) indicated that the fully parameterized model, including the interaction among vegetation type, disturbance, and park unit, best described the distribution of both total number of alien plants per transect and frequency of alien plants on transects where they occurred. Although all vegetation types were invaded by alien plants, mesic communities had both greater numbers and higher frequencies of alien plants than did drier communities. A strong element of stochasticity, reflected in differences in frequencies of individual species between the two park units, suggests that prediction of risk of invasion will always involve uncertainty. In addition, despite well-documented associations between anthropogenic disturbance and alien plant invasion, five of

  13. The prairie dog as a keystone species

    Science.gov (United States)

    Kotliar, Natasha B.; Miller, Brian J.; Reading, Richard P.; Clark, Timothy W.; Hoogland, John L.

    2006-01-01

    The prairie dog has a pronounced impact on its grassland ecosystem (King 1955; Uresk and Bjugstad 1983; Miller et al. 1994; Society for Conservation Biology 1994; Wuerthner 1997; Johnsgard 2005). They maintain short vegetation by their grazing and by selective removal of tall plants and shrubs; provide shelter, foraging grounds, and nesting habitat for a diverse array of animals; serve as prey for many predators; and alter soil chemistry.Do these impacts mean that the prairie dog is a keystone species? To investigate, we first scrutinize the definition for a keystone species. We then document both vertebrates and invertebrates that associate with prairie dogs and their colony-sites. We examine ecosystem processes at colony-sites, and then assess whether the prairie dog is a legitimate keystone species. Finally, we explore the implications of keystone status for the conservation of prairie dogs.

  14. Prairie Chicken

    Data.gov (United States)

    Kansas Data Access and Support Center — An outline of the general range occupied by greayter and lesser prairie chickens. The range was delineated by expert opinion, then varified by local wildlife...

  15. Black-tailed prairie dogs, cattle, and the conservation of North America's arid grasslands.

    Directory of Open Access Journals (Sweden)

    Rodrigo Sierra-Corona

    Full Text Available Prairie dogs (Cynomys spp. have been eliminated from over 95% of their historic range in large part from direct eradication campaigns to reduce their purported competition with cattle for forage. Despite the longstanding importance of this issue to grassland management and conservation, the ecological interactions between cattle and prairie dogs have not been well examined. We address this issue through two complementary experiments to determine if cattle and prairie dogs form a mutualistic grazing association similar to that between prairie dogs and American bison. Our experimental results show that cattle preferentially graze along prairie dog colony edges and use their colony centers for resting, resembling the mutualistic relationship prairie dogs have with American bison. Our results also show that prairie dog colonies are not only an important component of the grassland mosaic for maintaining biodiversity, but also provide benefits to cattle, thereby challenging the long-standing view of prairie dogs as an undesirable pest species in grasslands.

  16. Effect of total mixed ration composition and daily grazing pattern on milk production, composition and fatty acids profile of dairy cows.

    Science.gov (United States)

    Hernández-Ortega, Martha; Martínez-Fernández, Adela; Soldado, Ana; González, Amelia; Arriaga-Jordán, Carlos M; Argamentería, Alejandro; de la Roza-Delgado, Begoña; Vicente, Fernando

    2014-11-01

    The possibilities of using high quality pastures in conjunction with total mixed ration (TMR) during the grazing season have been examined. An experiment with sixteen Holstein cows blocked and randomly assigned to four treatments in a factorial arrangement was conducted in order to evaluate the influence of grazing time of day (day or night) and type of silage (maize or Italian ryegrass) included in the TMR of dairy cows grazing 12 h daily on milk yield, composition and fatty acid profile. The silage type had no effect on the dry matter intake, milk yield and fat and protein proportions. However, cows grazing during the night ate more grass than cows grazing during the day (8·53 vs. 5·65 kg DM/d; Pdairy cows grazing at night-time than grazing at day-time, especially 18:2n-6 (2·37 vs. 2·12 g/100 g FA respectively, P<0·05) and 18:2cis9trans11 (2·08 vs. 1·74 g/100 g FA respectively, P<0·05).

  17. Exotic plant infestation is associated with decreased modularity and increased numbers of connectors in mixed-grass prairie pollination networks

    Science.gov (United States)

    Larson, Diane L.; Rabie, Paul A.; Droege, Sam; Larson, Jennifer L.; Haar, Milton

    2016-01-01

    The majority of pollinating insects are generalists whose lifetimes overlap flowering periods of many potentially suitable plant species. Such generality is instrumental in allowing exotic plant species to invade pollination networks. The particulars of how existing networks change in response to an invasive plant over the course of its phenology are not well characterized, but may shed light on the probability of long-term effects on plant-pollinator interactions and the stability of network structure. Here we describe changes in network topology and modular structure of infested and non-infested networks during the flowering season of the generalist non-native flowering plant, Cirsium arvense in mixed-grass prairie at Badlands National Park, South Dakota, USA. Objectives were to compare network-level effects of infestation as they propagate over the season in infested and non-infested (with respect to C. arvense) networks. We characterized plant-pollinator networks on 5 non-infested and 7 infested 1-ha plots during 4 sample periods that collectively covered the length of C. arvense flowering period. Two other abundantly-flowering invasive plants were present during this time: Melilotus officinalis had highly variable floral abundance in both C. arvense-infested and non-infested plots andConvolvulus arvensis, which occurred almost exclusively in infested plots and peaked early in the season. Modularity, including roles of individual species, and network topology were assessed for each sample period as well as in pooled infested and non-infested networks. Differences in modularity and network metrics between infested and non-infested networks were limited to the third and fourth sample periods, during flower senescence of C. arvenseand the other invasive species; generality of pollinators rose concurrently, suggesting rewiring of the network and a lag effect of earlier floral abundance. Modularity was lower and number of connectors higher in infested

  18. An emerging crisis across northern prairie refuges: Prevalence of invasive plants and a plan for adaptive management

    Science.gov (United States)

    Grant, T.A.; Flanders-Wanner, B.; Shaffer, T.L.; Murphy, R.K.; Knutsen, G.A.

    2009-01-01

    In the northern Great Plains, native prairies managed by the U.S. Fish and Wildlife Service (Service) can be pivotal in conservation of North America's biological diversity. From 2002 to 2006, we surveyed 7,338 belt transects to assess the general composition of mixed-grass and tallgrass prairie vegetation across five "complexes" (i.e., administrative groupings) of national wildlife refuges managed by the Service in North Dakota and South Dakota. Native grasses and forbs were common (mean frequency of occurrence 47%-54%) on two complexes but uncommon (4%-13%) on two others. Conversely, an introduced species of grass, smooth brome (Bromus inermis), accounted for 45% to 49% of vegetation on two complexes and another species, Kentucky bluegrass (Poa pratensis) accounted for 27% to 36% of the vegetation on three of the complexes. Our data confirm prior suspicions of widespread invasion by introduced species of plants on Service-owned tracts of native prairie, changes that likely stem in part from a common management history of little or no disturbance (e.g., defoliation by grazing or fire). However, variability in the degree and type of invasion among prairie tracts suggests that knowledge of underlying causes (e.g., edaphic or climatic factors, management histories) could help managers more effectively restore prairies. We describe an adaptive management approach to acquire such knowledge while progressing with restoration. More specifically, we propose to use data from inventories of plant communities on Service-owned prairies to design and implement, as experiments, optimal restoration strategies. We will then monitor these experiments and use the results to refine future strategies. This comprehensive, process-oriented approach should yield reliable and robust recommendations for restoration and maintenance of native prairies in the northern Great Plains. 2009 by the Board of Regents of the University of Wisconsin System.

  19. Vesper Sparrows and Western Meadowlarks Show a Mixed Response to Cattle Grazing in the Intermountain Region of British Columbia

    Directory of Open Access Journals (Sweden)

    Megan L. Harrison

    2010-06-01

    Full Text Available Livestock grazing in the shortgrass steppe of the Intermountain region of British Columbia is predicted to have significant effects on grassland habitats and their associated ground-nesting bird communities. We tested whether grazed and ungrazed sites could be discriminated on the basis of their vegetation communities, whether the abundance of two ground-nesting bird species, Vesper Sparrow (Pooecetes gramineus and Western Meadowlark (Sturnella neglecta, differed between grazed and ungrazed sites, and whether vegetation variables found to differ between grazed and ungrazed plots could be used to predict the abundance of the two bird species at a fine scale. Grazed sites were easily distinguishable from a site that had been ungrazed for >30 years based on the structure and composition of their vegetation communities. However, more detailed grazing categories could not be distinguished on the basis of vegetation characteristics. Despite the existence of grazing effects on vegetation structure and composition, we found no consistent differences in abundance of Vesper Sparrows and Western Meadowlarks between the grazed and ungrazed sites. However, there was weak evidence that the abundance of both species was higher at fine-scale plots (100 m radius point count station with less bare ground and taller vegetation. Bare ground cover was lower on grazed plots, but vegetation was taller on ungrazed plots. Combined, our results suggest that low intensity grazing leads to grassland habitat change with both negative and positive effects on Vesper Sparrows and Western Meadowlarks, resulting in no net change in their broad-scale abundance.

  20. Comportamento ingestivo de cordeiras em pastagem consorciada de inverno sob diferentes intensidades de desfolha Ingestive behavior of lambs on mixed winter pasture under different grazing intensities

    Directory of Open Access Journals (Sweden)

    Carine Lisete Glienke

    2008-11-01

    Full Text Available Avaliou-se a relação entre a estrutura do pasto, as variáveis ambientais e o comportamento ingestivo de cordeiras Ile de France × Texel em pastagem consorciada de aveia-preta (Avena strigosa Schreb., azevém (Lolium multiflorum Lam. e trevo-vermelho (Trifolium pratense L. sob quatro intensidades de desfolha (muito alta, alta, média e baixa. Utilizaram-se pastejos intermitentes considerando a soma térmica de 300 graus-dia como critério para determinar os intervalos de pastejo. As avaliações do comportamento ingestivo foram feitas por meio de observação visual em quatro períodos contínuos de 24 horas realizados no período de maio a outubro de 2006. O maior tempo de pastejo ocorreu na intensidade baixa. Altas intensidades de desfolha ocasionaram aumento da densidade populacional de perfilhos de azevém e não alteraram o peso desses perfilhos. A massa de bocados e a qualidade da dieta selecionada pelas cordeiras foram semelhantes entre as intensidades testadas. Em pastagem de aveia+azevém+trevo-vermelho, quando o intervalo de pastejo é determinado pela soma térmica de 300 graus-dia, a utilização de intensidades de desfolha que variam de baixa a muito alta não altera o comportamento ingestivo de cordeiras. O comportamento ingestivo é afetado pelo ciclo do pasto e pelo fotoperíodo e a seletividade dos animais reduz ao final do período de utilização da pastagem, quando ocorre aumento no tempo de pastejo e na distância percorrida em busca de locais de alimentação.The relationship between the pasture structure, environmental variables and the ingestive behavior of crossbred Ile de France-Texel lambs on a mixed winter pasture of oats (Avena strigosa Schreb., Italian ryegrass (Lolium multiflorum Lam., and red clover (Trifolium pratense L. under four grazing intensities ('very high', 'high', 'average', and 'low' was evaluated. Intermittent grazing was used, considering the thermal sum of 300 degree-days to determine the grazing

  1. Macroinvertebrates in North American tallgrass prairie soils: effects of fire, mowing, and fertilization on density and biomass

    Science.gov (United States)

    M.A. Callaham; J.M. Blair; T.C. Todd; D.J. Kitchen; M.R. Whiles

    2003-01-01

    The responses of tallgrass prairie plant communities and ecosystem processes to fire and grazing are well characterized. However, responses of invertebrate consumer groups. and particularly soil-dwelling organisms, to these disturbances are not well known. At Konza Prairie Biological Station. we sampled soil macroinvertebrates in 1994 and 1999 as part of a long-term...

  2. Environmental Assessment: Black-Tailed Prairie Dog Management Cannon Air Force Base and Melrose Air Force Range, New Mexico

    Science.gov (United States)

    2005-12-01

    requirements are met by metabolizing grazed vegetation. Prairie dogs dig burrows to an average depth of 2-3 meters with some tunnels interconnecting with...the potential to impact non- target species such as mice, kangaroo rats, and some songbirds. Establishing control zones at CAFB and MAFR could not be...Gutierrezia sarothrae), and Russian thistle (Salsola iberica). Water requirements are met by metabolizing grazed vegetation. Prairie dogs dig burrows

  3. Long-term lesser prairie-chicken nest ecology in response to grassland management

    Science.gov (United States)

    Fritts, Sarah R.; Grisham, Blake A.; Haukos, David A.; Boal, Clint W.; Patten, Michael; Wolfe, Don H.; Dixon, Charles; Cox, Robert D.; Heck, Willard R.

    2016-01-01

    Long-term population and range declines from habitat loss and fragmentation caused the lesser prairie-chicken (Tympanuchus pallidicinctus) to be a species of concern throughout its range. Current lesser prairie-chicken range in New Mexico and Texas is partially restricted to sand shinnery oak (Quercus havardii; hereafter shinnery oak) prairies, on which cattle grazing is the main socioeconomic driver for private landowners. Cattle producers within shinnery oak prairies often focus land management on shrub eradication using the herbicide tebuthiuron to promote grass production for forage; however, herbicide application alone, and in combination with grazing, may affect nest site selection and nest survival of lesser prairie-chickens through the reduction of shinnery oak and native grasses. We used a controlled, paired, completely randomized design study to assess the influence of grazing and tebuthiuron application and their combined use on nest site selection and nest survival from 2001 to 2010 in Roosevelt County, New Mexico, USA at 2 spatial scales (i.e., treatment and microhabitat) in 4 treatments: tebuthiuron with grazing, tebuthiuron without grazing, no tebuthiuron with grazing, and a control of no tebuthiuron and no grazing. Grazing treatment was a short-duration system in which plots were grazed once during the dormant season and once during the growing season. Stocking rate was calculated each season based on measured forage production and applied to remove ≤25% of available herbaceous material per season. At the treatment scale, we compared nest site selection among treatments using 1-way χ2 tests and nest survival among treatments using a priori candidate nest survival models in Program MARK. At the microhabitat scale, we identified important habitat predictors of nest site selection and nest survival using logistic regression and a priori candidate nest survival models in Program MARK, respectively. Females typically used treatments as expected and

  4. Preserving prairies: Understanding temporal and spatial patterns of invasive annual bromes in the Northern Great Plains

    Science.gov (United States)

    Ashton, Isabel; Symstad, Amy J.; Davis, Christopher; Swanson, Daniel J.

    2016-01-01

    Two Eurasian invasive annual brome grasses, cheatgrass (Bromus tectorum) and Japanese brome (Bromus japonicus), are well known for their impact in steppe ecosystems of the western United States where these grasses have altered fire regimes, reduced native plant diversity and abundance, and degraded wildlife habitat. Annual bromes are also abundant in the grasslands of the Northern Great Plains (NGP), but their impact and ecology are not as well studied. It is unclear whether the lessons learned from the steppe will translate to the mixed-grass prairie where native plant species are adapted to frequent fires and grazing. Developing a successful annual brome management strategy for National Park Service units and other NGP grasslands requires better understanding of (1) the impact of annual bromes on grassland condition; (2) the dynamics of these species through space and time; and (3) the relative importance of environmental factors within and outside managers' control for these spatiotemporal dynamics. Here, we use vegetation monitoring data collected from 1998 to 2015 in 295 sites to relate spatiotemporal variability of annual brome grasses to grassland composition, weather, physical environmental characteristics, and ecological processes (grazing and fire). Concern about the impact of these species in NGP grasslands is warranted, as we found a decline in native species richness with increasing annual brome cover. Annual brome cover generally increased over the time of monitoring but also displayed a 3- to 5-yr cycle of reduction and resurgence. Relative cover of annual bromes in the monitored areas was best predicted by park unit, weather, extant plant community, slope grade, soil composition, and fire history. We found no evidence that grazing reduced annual brome cover, but this may be due to the relatively low grazing pressure in our study. By understanding the consequences and patterns of annual brome invasion, we will be better able to preserve and restore

  5. Prairie Conservation in Canada: The Prairie Conservation Action Plan Experience

    Science.gov (United States)

    Dean Nernberg; David Ingstrup

    2005-01-01

    In Canada, grassland conservation has been mobilized and directed through the development of Prairie Conservation Action Plans and Action Plan Committees in the three prairie provinces of Alberta (45 partner agencies and organizations), Saskatchewan (26 partners), and Manitoba (26 partners). In Alberta, 43 percent of the native prairie remains; in Saskatchewan and...

  6. A proposal to conserve black-footed ferrets and the prairie dog ecosystem

    Science.gov (United States)

    Miller, Brian; Wemmer, Christen; Biggins, Dean; Reading, Richard

    1990-11-01

    Prairie dogs ( Cynomys spp.) have been poisoned throughout this century because of grazing competition with livestock. Recent evidence showed these early claims were exaggerated, but animal control was already entrenched in government policy. As a result, ongoing government subsidized poisoning has reduced prairie dogs to about 2% of their former distribution. The reduction of prairie dogs diminished species diversity in the arid grasslands of North America, including the potential extinction of the black-footed ferret ( Mustela nigripes). Cost-benefit analysis revealed that poisoning costs more than any grazing benefits accrued. This analysis did not consider the long-term costs of reversing ecosystem degradation, the intangible value of biological diversity as a public benefit, or the depletion of biotic resources as a loss of actual or potential wealth. The government presently finances the poisoning policy and the preservation of endangered species like the black-footed ferret, two apparently conflicting programs. We, therefore, propose an integrated management plan that considers both interests. We propose that federal monies allocated to the poisoning program be converted into a rebate for ranchers who manage livestock while preserving the prairie dog community. This would redirect funds and personnel already allocated to prairie dog eradication to an incentive for ranchers who manage for livestock and wildlife. Livestock interests and grassland biotic diversity would both benefit.

  7. Establishment of prairies

    International Nuclear Information System (INIS)

    Lotero Cadavid, J.

    2001-01-01

    Are analyzed the establishment of prairies, such as the selection of the species, the factors of the environment, the impact in the establishment and forage production and its relation to the soil, the precipitation, the temperature, the light and the biotic factors. It is indicated that the selection of the species to settle down, is directly related with the climate and the soil and they group to be tolerant to drought, tolerant to flood soils, tolerant to humid soils, tolerant to soils very acids, moderately acids and saline. It is noticed that a bad establishment of the grasses can be due to the bad quality of the seed, a temperature and unfavorable humidity can cause low germination; equally seeds planted very deeply in heavy soils with excess of humidity. Considerations are made about the establishment and growth of the prairies in connection with the germination, cultures, sowing density and sowing on time, as well as for the soil preparation, the sowing in terrestrial mechanic and non mechanic and the use of cultivations forms of low cost and fertilization systems; equally the establishment of leguminous in mixture with gramineous, the renovation of prairies and the establishment of pastures

  8. Climate change and prairie pothole wetlands: mitigating water-level and hydroperiod effects through upland management

    Science.gov (United States)

    Renton, David A.; Mushet, David M.; DeKeyser, Edward S.

    2015-01-01

    Prairie pothole wetlands offer crucial habitat for North America’s waterfowl populations. The wetlands also support an abundance of other species and provide ecological services valued by society. The hydrology of prairie pothole wetlands is dependent on atmospheric interactions. Therefore, changes to the region’s climate can have profound effects on wetland hydrology. The relevant literature related to climate change and upland management effects on prairie pothole wetland water levels and hydroperiods was reviewed. Climate change is widely expected to affect water levels and hydroperiods of prairie pothole wetlands, as well as the biota and ecological services that the wetlands support. In general, hydrologic model projections that incorporate future climate change scenarios forecast lower water levels in prairie pothole wetlands and longer periods spent in a dry condition, despite potential increases in precipitation. However, the extreme natural variability in climate and hydrology of prairie pothole wetlands necessitates caution when interpreting model results. Recent changes in weather patterns throughout much of the Prairie Pothole Region have been in increased precipitation that results in increased water inputs to wetlands above losses associated with warmer temperatures. However, observed precipitation increases are within the range of natural climate variability and therefore, may not persist. Identifying management techniques with the potential to affect water inputs to prairie pothole wetlands would provide increased options for managers when dealing with the uncertainties associated with a changing climate. Several grassland management techniques (for example, grazing and burning) have the potential to affect water levels and hydroperiods of prairie pothole by affecting infiltration, evapotranspiration, and snow deposition.

  9. Grassland Fire and Cattle Grazing Regulate Reptile and Amphibian Assembly Among Patches

    Science.gov (United States)

    Larson, Danelle M.

    2014-12-01

    Fire and grazing are common management schemes of grasslands globally and are potential drivers of reptilian and amphibian (herpetofauna) metacommunity dynamics. Few studies have assessed the impacts of fire and cattle grazing on herpetofauna assemblages in grasslands. A patch-burn grazing study at Osage Prairie, MO, USA in 2011-2012 created landscape patches with treatments of grazing, fire, and such legacies. Response variables were measured before and after the application of treatments, and I used robust-design occupancy modeling to estimate patch occupancy and detection rate within patches, and recolonization and extinction (i.e., dispersal) across patches. I conducted redundancy analysis and a permuted multivariate analysis of variance to determine if patch type and the associated environmental factors explained herpetofauna assemblage. Estimates for reptiles indicate that occupancy was seasonally constant in Control patches ( ψ ~ 0.5), but declined to ψ ~ 0.15 in patches following the applications of fire and grazing. Local extinctions for reptiles were higher in patches with fire or light grazing ( ɛ ~ 0.7) compared to the controls. For the riparian herpetofaunal community, patch type and grass height were important predictors of abundance; further, the turtles, lizards, snakes, and adult amphibians used different patch types. The aquatic amphibian community was predicted by watershed and in-stream characteristics, irrespective of fire or grazing. The varying responses from taxonomic groups demonstrate habitat partitioning across multiple patch types undergoing fire, cattle grazing, and legacy effects. Prairies will need an array of patch types to accommodate multiple herpetofauna species.

  10. Power and limitation of soil properties as predictors of rangeland health and ecosystem functioning in a Northern mixed-grass prairie[Abstract

    Science.gov (United States)

    Soil properties are thought to affect rangeland ecosystem functioning (e.g. primary productivity, hydrology), and thus soil variables that are consistently correlated with key ecosystem functions may be general indicators of rangeland health. We summarize results from several studies in mixed-grass...

  11. Impacts of mesquite distribution on seasonal space use of lesser prairie-chickens

    Science.gov (United States)

    Boggie, Matthew A.; Strong, Cody R.; Lusk, Daniel; Carleton, Scott A.; Gould, William R.; Howard, Randy L.; Nichols, Clay T.; Falkowski, Michael J.; Hagen, Christian A.

    2017-01-01

    Loss of native grasslands by anthropogenic disturbances has reduced availability and connectivity of habitat for many grassland species. A primary threat to contiguous grasslands is the encroachment of woody vegetation, which is spurred by disturbances that take on many forms from energy development, fire suppression, and grazing. These disturbances are exacerbated by natural- and human-driven cycles of changes in climate punctuated by drought and desertification conditions. Encroachment of honey mesquite (Prosopis glandulosa) into the prairies of southeastern New Mexico has potentially limited habitat for numerous grassland species, including lesser prairie-chickens (Tympanuchus pallidicinctus). To determine the magnitude of impacts of distribution of mesquite and how lesser prairie-chickens respond to mesquite presence on the landscape in southeastern New Mexico, we evaluated seasonal space use of lesser prairie-chickens in the breeding and nonbreeding seasons. We derived several remotely sensed spatial metrics to characterize the distribution of mesquite. We then used these data to create population-level resource utilization functions and predict intensity of use of lesser prairie-chickens across our study area. Home ranges were smaller in the breeding season compared with the nonbreeding season; however, habitat use was similar across seasons. During both seasons, lesser prairie-chickens used areas closer to leks and largely avoided areas with mesquite. Relative to the breeding season, during the nonbreeding season habitat use suggested a marginal increase in mesquite within areas of low intensity of use, yet aversion to mesquite was strong in areas of medium to high intensity of use. To our knowledge, our study is the first to demonstrate a negative behavioral response by lesser prairie-chickens to woody encroachment in native grasslands. To mitigate one of the possible limiting factors for lesser prairie-chickens, we suggest future conservation

  12. Predation of artificial ground nests on white-tailed prairie dog colonies

    Science.gov (United States)

    Baker, B.W.; Stanley, T.R.; Sedgwick, J.A.

    1999-01-01

    Prairie dog (Cynomys spp.) colonies are unique to prairie and shrub-steppe landscapes. However, widespread eradication, habitat loss, and sylvatic plague (Yersinia pestis) have reduced their numbers by 98% since historical times. Birds associated with prairie dogs also are declining. Potential nest predators, such as coyotes (Canis latrans), swift foxes (Vulpes velox), and badgers (Taxidea taxus), may be attracted to colonies where a high concentration of prairie dogs serve as available prey. Increased abundance of small mammals, including prairie dogs, also may increase the risk of predation for birds nesting on colonies. Finally, because grazing by prairie dogs may decrease vegetation height and canopy cover, bird nests may be easier for predators to locate. In this study, we placed 1,444 artificial ground nests on and off 74 white-tailed prairie dog (C. leucurus) colonies to test the hypothesis that nest predation rates are higher on colonies than at nearby off sites (i.e., uncolonized habitat). We sampled colonies from 27 May to 16 July 1997 at the following 3 complexes: Coyote Basin, Utah and Colorado; Moxa Arch, Wyoming; and Shirley Basin, Wyoming. Differences in daily predation rates between colonies and paired off sites averaged 1.0% (P = 0.060). When converted to a typical 14-day incubation period, predation rates averaged 14% higher on colonies (57.7 ?? 2.7%; ?? ?? SE) than at off sites (50.4 ?? 3.1%). Comparisons of habitat variables on colonies to off sites showed percent canopy cover of vegetation was similar (P = 0.114), percent bare ground was higher on colonies (P 0.288). Although we found the risk of nest predation was higher on white-tailed prairie dog colonies than at off sites, fitness of birds nesting on colonies might depend on other factors that influence foraging success, reproductive success, or nestling survival.

  13. Rangewide genetic analysis of Lesser Prairie-Chicken reveals population structure, range expansion, and possible introgression

    Science.gov (United States)

    Oyler-McCance, Sara J.; DeYoung, Randall W; Fike, Jennifer; Hagen, Christian A.; Johnson, Jeff A.; Larsson, Lena C.; Patten, Michael

    2016-01-01

    The distribution of the Lesser Prairie-Chicken (Tympanuchus pallidicinctus) has been markedly reduced due to loss and fragmentation of habitat. Portions of the historical range, however, have been recolonized and even expanded due to planting of conservation reserve program (CRP) fields that provide favorable vegetation structure for Lesser Prairie-Chickens. The source population(s) feeding the range expansion is unknown, yet has resulted in overlap between Lesser and Greater Prairie-Chickens (T. cupido) increasing the potential for hybridization. Our objectives were to characterize connectivity and genetic diversity among populations, identify source population(s) of recent range expansion, and examine hybridization with the Greater Prairie-Chicken. We analyzed 640 samples from across the range using 13 microsatellites. We identified three to four populations corresponding largely to ecoregions. The Shinnery Oak Prairie and Sand Sagebrush Prairie represented genetically distinct populations (F ST > 0.034 and F ST > 0.023 respectively). The Shortgrass/CRP Mosaic and Mixed Grass ecoregions appeared admixed (F ST = 0.009). Genetic diversity was similar among ecoregions and N e ranged from 142 (95 % CI 99–236) for the Shortgrass/CRP Mosaic to 296 (95 % CI 233–396) in the Mixed Grass Prairie. No recent migration was detected among ecoregions, except asymmetric dispersal from both the Mixed Grass Prairie and to a lesser extent the Sand Sagebrush Prairie north into adjacent Shortgrass/CRP Mosaic (m = 0.207, 95 % CI 0.116–0.298, m = 0.097, 95 % CI 0.010–0.183, respectively). Indices investigating potential hybridization in the Shortgrass/CRP Mosaic revealed that six of the 13 individuals with hybrid phenotypes were significantly admixed suggesting hybridization. Continued monitoring of diversity within and among ecoregions is warranted as are actions promoting genetic connectivity and range expansion.

  14. Revealing livestock effects on bunchgrass vegetation with Landsat ETM+ data across a grazing season

    Science.gov (United States)

    Jansen, Vincent S.

    Remote sensing provides monitoring solutions for more informed grazing management. To investigate the ability to detect the effects of cattle grazing on bunchgrass vegetation with Landsat Enhanced Thematic Mapper Plus (ETM+) data, we conducted a study on the Zumwalt Prairie in northeastern Oregon across a gradient of grazing intensities. Biophysical vegetation data was collected on vertical structure, biomass, and cover at three different time periods during the grazing season: June, August, and October 2012. To relate these measures to the remotely sensed Landsat ETM+ data, Pearson's correlations and multiple regression models were computed. Using the best models, predicted vegetation metrics were then mapped across the study area. Results indicated that models using common vegetation indices had the ability to discern different levels of grazing across the study area. Results can be distributed to land managers to help guide grassland conservation by improving monitoring of bunchgrass vegetation for sustainable livestock management.

  15. Des broussailles dans les prairies alpines

    Directory of Open Access Journals (Sweden)

    Olivier Camacho

    2009-03-01

    Full Text Available Landscape closing due to the decline in agricultural activity is considered to be a major problem in the Alps. Abondance Valley provides a good example of this phenomenon and is also representative of a paradox commonly found in the Northern French Alps: the mountainsides and alpine pastures are still used, whereas they are becoming increasingly afforested. Environmental conditions play a major role in the localisation of agricultural land uses, but they are not sufficient to explain why pastures still in use are being invaded by shrub. Even if cutting makes it possible to effectively control the encroachment by woody species, this is not true for uncut pastures where grazing is not able to keep up with grass production. This situation is repeated every year and is the likely cause of the colonisation by woody species. To ensure their forage system and to simplify their work, farmers tend to establish grazing units that are oversized in relation to the needs of their animals. They implement compensatory practices that consist of mechanical maintenance as a complement to grazing to limit the dynamics of woody species. These labour-intensive practices are not used on all of the pastures. The analysis of farmers’ practices by agronomists is therefore a useful complement to studies of physical and socio-economic environments, at the level of the grazed field as well as at that of the valley as a whole.La dégradation des paysages par suite du recul de l’activité agricole est considérée comme un enjeu majeur dans les Alpes. La vallée d’Abondance illustre bien ce phénomène de fermeture de l’espace mais elle est en outre représentative d’un paradoxe assez répandu dans les Alpes du nord françaises : les versants et les alpages sont encore exploités et pourtant ils se boisent progressivement. Les conditions de milieux jouent un rôle majeur sur la localisation des usages agricoles de l'espace, mais elles ne peuvent pas suffire pour

  16. Habitat edge, land management, and rates of brood parasitism in tallgrass prairie.

    Science.gov (United States)

    Patten, Michael A; Shochat, Eyal; Reinking, Dan L; Wolfe, Donald H; Sherrod, Steve K

    2006-04-01

    Bird populations in North America's grasslands have declined sharply in recent decades. These declines are traceable, in large part, to habitat loss, but management of tallgrass prairie also has an impact. An indirect source of decline potentially associated with management is brood parasitism by the Brown-headed Cowbird (Molothrus ater), which has had substantial negative impacts on many passerine hosts. Using a novel application of regression trees, we analyzed an extensive five-year set of nest data to test how management of tallgrass prairie affected rates of brood parasitism. We examined seven landscape features that may have been associated with parasitism: presence of edge, burning, or grazing, and distance of the nest from woody vegetation, water, roads, or fences. All five grassland passerines that we included in the analyses exhibited evidence of an edge effect: the Grasshopper Sparrow (Ammodramus savannarum), Henslow's Sparrow (A. henslowii), Dickcissel (Spiza americana), Red-winged Blackbird (Agelaius phoeniceus), and Eastern Meadowlark (Sturnella magna). The edge was represented by narrow strips of woody vegetation occurring along roadsides cut through tallgrass prairie. The sparrows avoided nesting along these woody edges, whereas the other three species experienced significantly higher (1.9-5.3x) rates of parasitism along edges than in prairie. The edge effect could be related directly to increase in parasitism rate with decreased distance from woody vegetation. After accounting for edge effect in these three species, we found evidence for significantly higher (2.5-10.5x) rates of parasitism in grazed plots, particularly those burned in spring to increase forage, than in undisturbed prairie. Regression tree analysis proved to be an important tool for hierarchically parsing various landscape features that affect parasitism rates. We conclude that, on the Great Plains, rates of brood parasitism are strongly associated with relatively recent road cuts

  17. The Effect of Different Type of Herbivores, Grazing Types and Grazing Intensities on Alpine Basiphillous Vegetation of the Romanian Carpathians

    Science.gov (United States)

    Ballová, Zuzana; Pekárik, Ladislav; Šibík, Jozef

    2017-04-01

    The major purpose of the present study was to test the hypothesis that there are significant differences in vegetation structure, plant species composition, and soil chemical properties in relation to type of grazing animals, various levels of grazing intensity and grazing type, and if potential differences alter with ecosystem productivity (increase in more productive ecosystems). The study was conducted in three mountain ranges of the Romanian Carpathians with a predominance of alkaline substrates (the Bucegi Mts, the Little Retezat Mts and the Ceahlău Massif). Statistical analyses were performed in R statistical software environment. The effects of grazing animals (cattle, horses and sheep), grazing types (fence, regular, irregular) and grazing intensity (low, medium, high) on the community structure were tested using ordination methods. In the case of soil properties, General Linear Mixed Model was applied. Special statistical approach eliminated the differences between the examined mountains and sites. Type of grazing animal does not significantly influence species cover but it is related to specific species occurrence. According to our results, grazing horses had similar effects as cattle compared to sheep. Grazing in restricted areas (surrounded by fence) and regular unrestricted grazing were more similar if compared to irregular grazing. When comparing the intensity of grazing, high and medium intensity were more similar to each other than to the low intensity grazing. Cattle grazed sites had significantly higher lichens cover, while the sheep patches were covered with increased overall herb layer (forbs, graminoids and low shrubs together). Medium grazing intensity decreased the lichens cover, cover of overall herb layer, and total vegetation cover compared to high and low grazing intensity. Grazing type had important impact on the lichens cover and cover of overall herb layer. The lichens cover appeared to decrease while the cover of overall herb layer

  18. Development and application of a spatial IBM to forecast greater prairie-chicken population responses to land use in the Flint Hills region of Kansas - SCB meeting

    Science.gov (United States)

    Greater prairie-chicken (Tympanachus cupido) populations have been on the decline for decades. Recent efforts to reverse this trend are focusing on two specific disturbance regimes, cattle grazing and field burning, both prevalent in the Flint Hill region of Kansas -- an area of...

  19. Development and application of a spatial IBM to forecast greater prairie-chicken population responses to land use in the Flint Hills region of Kansas

    Science.gov (United States)

    Greater prairie-chicken (Tympanachus cupido) populations have been on the decline for decades. Recent efforts to reverse this trend are focusing on two specific disturbance regimes, cattle grazing and field burning, both prevalent in the Flint Hill region of Kansas -- an area of...

  20. Variable effects of dipteran parasitoids and management treatment on grasshopper fecundity in a tallgrass prairie.

    Science.gov (United States)

    Laws, A N; Joern, A

    2012-04-01

    Grasshoppers host a number of parasitoids, but little is known about their impact on grasshopper life history attributes or how those impacts may vary with land use. Here, we report on a three-year survey of nine grasshopper species in a tallgrass prairie managed with fire and bison grazing treatments. We measured parasitoid prevalence and the impact of parasitoid infection on grasshopper fecundity to determine if grasshopper-parasitoid interactions varied with management treatment. Adult female grasshoppers were collected every three weeks from eight watersheds managed with different prescribed burning and grazing treatments. Grasshopper fecundity with and without parasitoids was estimated through dissections of reproductive tracts. Dipteran parasitoids from two families (Nemestrinidae and Tachinidae) were observed infecting grasshoppers. We found significant effects of grazing treatment, but not burn interval, on grasshopper-parasitoid interactions. Parasitoids were three times more abundant in watersheds with bison grazing than in ungrazed watersheds, and the relative abundance of nemestrinid and tachinid flies varied with grazing treatment. Parasitoid prevalence varied among grasshopper species from grasshopper fecundity, with stronger effects on current reproduction than on past reproduction. Furthermore, current fecundity in parasitized grasshoppers was lower in grazed watersheds compared to ungrazed watersheds. Nemestrinid parasitoids generally had stronger impacts on grasshopper fecundity than tachinid parasitoids, the effects of which were more variable.

  1. Vegetation of wetlands of the prairie pothole region

    Science.gov (United States)

    Kantrud, H.A.; Millar, J.B.; Van Der Valk, A.G.; van der Valk, A.

    1989-01-01

    Five themes dominate the literature dealing with the vegetation of palustrine and lacustrine wetlands of the prairie pothole region: environmental conditions (water or moisture regime, salinity), agricultural disturbances (draining, grazing, burning, sedimentation, etc.), vegetation dynamics, zonation patterns, and classification of the wetlands.The flora of a prairie wetland is a function of its water regime, salinity, and disturbance by man. Within a pothole, water depth and duration determines distribution of species. In potholes deep enough to have standing water even during droughts, the central zone will be dominated by submersed species (open water). In wetlands that go dry during periods of drought or annually, the central zone will be dominated by either tall emergent species (deep marsh) or midheight emergents (shallow marsh), respectively. Potholes that are only flooded briefly in the spring are dominated by grasses, sedges, and forbs (wet meadow). Within a pothole, the depth of standing water in the deepest, usually central, part of the basin determines how many zones will be present. Lists of species associated with different water regimes and salinity levels are presented.Disturbances due to agricultural activities have impacted wetlands throughout the region. Drainage has eliminated many potholes, particularly in the southern and eastern parts of the region. Grazing, mowing, and burning have altered the composition of pothole vegetation. The composition of different vegetation types impacted by grazing, haying, and cultivation is presented in a series of tables. Indirect impacts of agriculture (increased sediment, nutrient, and pesticide inputs) are widespread over the region, but their impacts on the vegetation have never been studied.Because of the periodic droughts and wet periods, many palustrine and lacustrine wetlands undergo vegetation cycles associated with water-level changes produced by these wet-dry cycles. Periods of above normal

  2. Native Prairie Adaptive Management: a multi region adaptive approach to invasive plant management on Fish and Wildlife Service owned native prairies

    Science.gov (United States)

    Gannon, Jill J.; Shaffer, Terry L.; Moore, Clinton T.

    2013-01-01

    : increase the composition of native grasses and forbs on native sod while minimizing cost. Cooperators agreed that decision guidance should be provided annually and should account for local, real-time vegetation conditions observed on the ground. Over the course of development, two prototypes of the decision framework were considered. The final framework recognized four alternative actions that managers could take in any given year: (1) Graze—targeted use of grazing ungulates to achieve defoliation, (2) Burn—application of prescribed fire as the single form of defoliation, (3) Burn/Graze—a combination treatment, and (4) Rest—no action. The study area included northern mixed-grass and tallgrass prairie. Native vegetation in mixed–grass prairie has a strong cool-season component and thus the dominant native species have a phenology similar to that of smooth brome and Kentucky bluegrass, making management of those species challenging. In contrast, tallgrass prairie has a strong warm-season native component, leading to an existence of cool-season windows, periods of time in the fall and spring when cool‐season invasive grass species are actively growing and vulnerable to damage via select management actions, but warm‐season grass species are not active and are thus less susceptible to damage via the same actions. This dichotomy between prairie types necessitated the development of separate but parallel decision support systems for mixed-grass and tallgrass biomes. Management units are parcels of native prairie that receive a single management treatment at any one time over their entire extent. At any particular time, the vegetation state of each management unit is characterized by the amount of cover of native grasses and forbs and the type of invasive grass that is dominant. In addition, each unit has a defoliation state which reflects the number of years since the last defoliation event and an index to how intensively the unit was managed during the previous 7

  3. Dynamic Disturbance Processes Create Dynamic Lek Site Selection in a Prairie Grouse.

    Directory of Open Access Journals (Sweden)

    Torre J Hovick

    Full Text Available It is well understood that landscape processes can affect habitat selection patterns, movements, and species persistence. These selection patterns may be altered or even eliminated as a result of changes in disturbance regimes and a concomitant management focus on uniform, moderate disturbance across landscapes. To assess how restored landscape heterogeneity influences habitat selection patterns, we examined 21 years (1991, 1993-2012 of Greater Prairie-Chicken (Tympanuchus cupido lek location data in tallgrass prairie with restored fire and grazing processes. Our study took place at The Nature Conservancy's Tallgrass Prairie Preserve located at the southern extent of Flint Hills in northeastern Oklahoma. We specifically addressed stability of lek locations in the context of the fire-grazing interaction, and the environmental factors influencing lek locations. We found that lek locations were dynamic in a landscape with interacting fire and grazing. While previous conservation efforts have treated leks as stable with high site fidelity in static landscapes, a majority of lek locations in our study (i.e., 65% moved by nearly one kilometer on an annual basis in this dynamic setting. Lek sites were in elevated areas with low tree cover and low road density. Additionally, lek site selection was influenced by an interaction of fire and patch edge, indicating that in recently burned patches, leks were located near patch edges. These results suggest that dynamic and interactive processes such as fire and grazing that restore heterogeneity to grasslands do influence habitat selection patterns in prairie grouse, a phenomenon that is likely to apply throughout the Greater Prairie-Chicken's distribution when dynamic processes are restored. As conservation moves toward restoring dynamic historic disturbance patterns, it will be important that siting and planning of anthropogenic structures (e.g., wind energy, oil and gas and management plans not view lek

  4. Implementing Rotational Partial Rest/Patch-Burn Grazing in the Flint Hills, Kansas

    Science.gov (United States)

    2008-09-30

    recently published a paper about the project in Ecological Restoration, titled Managing for Grassland Diversity: A Study on Grazing-Fire Interactions in...Eagle, print and online editions July 2008 From Beef to Butterflies: Enhancing Diversity in the Tallgrass Prairie Plants & Pollinators Symposium...Wolfe, E. Shochat, and S.K. Sherrod. 2005. Habitat fragmentation, rapid evolution and population persistence. Evolutionary Ecology Research 7: 235-249

  5. Mapping wetlands and surface water in the Prairie Pothole Region of North America: Chapter 16

    Science.gov (United States)

    Rover, Jennifer R.; Mushet, David M.

    2015-01-01

    The Prairie Pothole Region (PPR) is one of the most highly productive wetland regions in the world. Prairie Pothole wetlands serve as a primary feeding and breeding habitat for more than one-half of North America’s waterfowl population, as well as a variety of songbirds, waterbirds, shorebirds, and other wildlife. During the last century, extensive land conversions from grassland with wetlands to cultivated cropland and grazed pastureland segmented and reduced wetland habitat. Inventorying and characterizing remaining wetland habitat is critical for the management of wetland ecosystem services. Remote sensing technologies are often utilized for mapping and monitoring wetlands. This chapter presents background specific to the PPR and discusses approaches employed in mapping its wetlands before presenting a case study.

  6. Long-term prairie falcon population changes in relation to prey abundance, weather, land uses, and habitat conditions

    Science.gov (United States)

    Steenhof, Karen; Kochert, Michael N.; Carpenter, L.B.; Lehman, Robert N.

    1999-01-01

    We studied a nesting population of Prairie Falcons (Falco mexicanus) in the Snake River Birds of Prey National Conservation Area (NCA) from 1974-1997 to identify factors that influence abundance and reproduction. Our sampling period included two major droughts and associated crashes in Townsend's ground squirrel (Spermophilus townsendii) populations. The number of Prairie Falcon pairs found on long-term survey segments declined significantly from 1976-1997. Early declines were most severe at the eastern end of the NCA, where fires and agriculture have changed native shrubsteppe habitat. More recent declines occurred in the portion of canyon near the Orchard Training Area (OTA), where the Idaho Army National Guard conducts artillery firing and tank maneuvers. Overall Prairie Falcon reproductive rates were tied closely to annual indexes of ground squirrel abundance, but precipitation before and during the breeding season was related inversely to some measures of reproduction. Most reproductive parameters showed no significant trends over time, but during the 1990s, nesting success and productivity were lower in the stretch of canyon near the OTA than in adjacent areas. Extensive shrub loss, by itself, did not explain the pattern of declines in abundance and reproduction that we observed. Recent military training activities likely have interacted with fire and livestock grazing to create less than favorable foraging opportunities for Prairie Falcons in a large part of the NCA. To maintain Prairie Falcon populations in the NCA, managers should suppress wildfires, restore native plant communities, and regulate potentially incompatible land uses.

  7. Song and Male Quality in Prairie Warblers

    Science.gov (United States)

    Bruce E. Byers; Michael E. Akresh; David I. King; W. Koenig

    2016-01-01

    To determine if the songs of male prairie warblers could potentially reveal to female listeners information about the quality of singers, we compared various aspects of prairie warbler song structure and performance to attributes that might reflect a male singer's potential to enhance the fitness of his mate. We found that all the tested male attributes—arrival...

  8. Interactive effects between nest microclimate and nest vegetation structure confirm microclimate thresholds for Lesser Prairie-Chicken nest survival

    Science.gov (United States)

    Grisham, Blake A.; Godar, Alixandra J.; Boal, Clint W.; Haukos, David A.

    2016-01-01

    The range of Lesser Prairie-Chickens (Tympanuchus pallidicinctus) spans 4 unique ecoregions along 2 distinct environmental gradients. The Sand Shinnery Oak Prairie ecoregion of the Southern High Plains of New Mexico and Texas is environmentally isolated, warmer, and more arid than the Short-Grass, Sand Sagebrush, and Mixed-Grass Prairie ecoregions in Colorado, Kansas, Oklahoma, and the northeast panhandle of Texas. Weather is known to influence Lesser Prairie-Chicken nest survival in the Sand Shinnery Oak Prairie ecoregion; regional variation may also influence nest microclimate and, ultimately, survival during incubation. To address this question, we placed data loggers adjacent to nests during incubation to quantify temperature and humidity distribution functions in 3 ecoregions. We developed a suite of a priori nest survival models that incorporated derived microclimate parameters and visual obstruction as covariates in Program MARK. We monitored 49 nests in Mixed-Grass, 22 nests in Sand Shinnery Oak, and 30 nests in Short-Grass ecoregions from 2010 to 2014. Our findings indicated that (1) the Sand Shinnery Oak Prairie ecoregion was hotter and drier during incubation than the Mixed- and Short-Grass ecoregions; (2) nest microclimate varied among years within ecoregions; (3) visual obstruction was positively associated with nest survival; but (4) daily nest survival probability decreased by 10% every half-hour when temperature was greater than 34°C and vapor pressure deficit was less than −23 mmHg during the day (about 0600–2100 hours). Our major finding confirmed microclimate thresholds for nest survival under natural conditions across the species' distribution, although Lesser Prairie-Chickens are more likely to experience microclimate conditions that result in nest failures in the Sand Shinnery Oak Prairie ecoregion. The species would benefit from identification of thermal landscapes and management actions that promote cooler, more humid nest microclimates.

  9. Lesser prairie-chicken nest site selection, microclimate, and nest survival in association with vegetation response to a grassland restoration program

    Science.gov (United States)

    Boal, Clint W.; Grisham, Blake A.; Haukos, David A.; Zavaleta, Jennifer C.; Dixon, Charles

    2014-01-01

    Climate models predict that the region of the Great Plains Landscape Conservation Cooperative (GPLCC) will experience increased maximum and minimum temperatures, reduced frequency but greater intensity of precipitation events, and earlier springs. These climate changes along with different landscape management techniques may influence the persistence of the lesser prairie-chicken (Tympanuchus pallidicinctus), a candidate for protection under the Endangered Species Act and a priority species under the GPLCC, in positive or negative ways. The objectives of this study were to conduct (1) a literature review of lesser prairie-chicken nesting phenology and ecology, (2) an analysis of thermal aspects of lesser prairie-chicken nest microclimate data, and (3) an analysis of nest site selection, nest survival, and vegetation response to 10 years of tebuthiuron and/or grazing treatments. We found few reports in the literature containing useful data on the nesting phenology of lesser prairie-chickens; therefore, managers must rely on short-term observations and measurements of parameters that provide some predictive insight into climate impacts on nesting ecology. Our field studies showed that prairie-chickens on nests were able to maintain relatively consistent average nest temperature of 31 °C and nest humidities of 56.8 percent whereas average external temperatures (20.3–35.0 °C) and humidities (35.2–74.9 percent) varied widely throughout the 24 hour (hr) cycle. Grazing and herbicide treatments within our experimental areas were designed to be less intensive than in common practice. We determined nest locations by radio-tagging hen lesser prairie-chickens captured at leks, which are display grounds at which male lesser prairie-chickens aggregate and attempt to attract a female for mating. Because nest locations selected by hen lesser prairie-chicken are strongly associated with the lek at which they were captured, we assessed nesting habitat use on the basis of hens

  10. Black-tailed prairie dog status and future conservation planning

    Science.gov (United States)

    Daniel W. Mulhern; Craig J. Knowles

    1997-01-01

    The black-tailed prairie dog is one of five prairie dog species estimated to have once occupied up to 100 million ha or more in North America. The area occupied by black-tailed prairie dogs has declined to approximately 2% of its former range. Conversion of habitat to other land uses and widespread prairie dog eradication efforts combined with sylvatic plague,

  11. Sodium co-limits and catalyzes macronutrients in a prairie food web

    DEFF Research Database (Denmark)

    Kaspari, Michael; Roeder, Karl A.; Benson, Brittany

    2017-01-01

    Nitrogen and phosphorus frequently limit terrestrial plant production, but have a mixed record in regulating the abundance of terrestrial invertebrates. We contrasted four ways that Na could interact with an NP fertilizer to shape the plants and invertebrates of an inland prairie. We applied NP a...

  12. Native prairie revegetation on wellsites in southeastern Alberta

    International Nuclear Information System (INIS)

    Soulodre, E.; Naeth, A.; Hammermeister, A.

    1999-01-01

    The Native Prairie Revegetation Research Project (NPRRP) was initiated to address concerns about wellsite revegetation of native grassland. The objective was to determine the impact of alternative seeding treatments on soil and vegetation and to produce a quantifiable description of what constitutes successful revegetation of native prairie sites. Four wellsites, each site comprising four revegetation treatment plots and an undisturbed control plot, have been chosen for field study. The revegetation treatments included natural recovery without seeding; current mix dominated by native wheatgrass cultivars; simple mix seeding containing wheatgrasses plus other native grasses, and diverse mix seeding with a mixture of wheatgrasses, other grasses and thirteen perennial forbs. The plant communities were monitored for biomass production, species richness, species composition and a combination of factors which include density, frequency, canopy cover and basal cover, these collectively representing importance value. Nitrogen availability in the soil was also monitored. Results showed high importance values for wheatgrasses for all seeded treatments. Perennial non-wheatgrasses had low importance values in the seeded treatment but higher importance in the control plot. The dominance of wheatgrasses in the seeded treatments resulted in communities that differed significantly from both the control and natural recovery communities, probably due to suppression of the growth of other grasses

  13. Model estimation of land-use effects on water levels of northern Prairie wetlands

    Science.gov (United States)

    Voldseth, R.A.; Johnson, W.C.; Gilmanov, T.; Guntenspergen, G.R.; Millett, B.V.

    2007-01-01

    Wetlands of the Prairie Pothole Region exist in a matrix of grassland dominated by intensive pastoral and cultivation agriculture. Recent conservation management has emphasized the conversion of cultivated farmland and degraded pastures to intact grassland to improve upland nesting habitat. The consequences of changes in land-use cover that alter watershed processes have not been evaluated relative to their effect on the water budgets and vegetation dynamics of associated wetlands. We simulated the effect of upland agricultural practices on the water budget and vegetation of a semipermanent prairie wetland by modifying a previously published mathematical model (WETSIM). Watershed cover/land-use practices were categorized as unmanaged grassland (native grass, smooth brome), managed grassland (moderately heavily grazed, prescribed burned), cultivated crops (row crop, small grain), and alfalfa hayland. Model simulations showed that differing rates of evapotranspiration and runoff associated with different upland plant-cover categories in the surrounding catchment produced differences in wetland water budgets and linked ecological dynamics. Wetland water levels were highest and vegetation the most dynamic under the managed-grassland simulations, while water levels were the lowest and vegetation the least dynamic under the unmanaged-grassland simulations. The modeling results suggest that unmanaged grassland, often planted for waterfowl nesting, may produce the least favorable wetland conditions for birds, especially in drier regions of the Prairie Pothole Region. These results stand as hypotheses that urgently need to be verified with empirical data.

  14. A multivariate analysis of biophysical parameters of tallgrass prairie among land management practices and years

    Science.gov (United States)

    Griffith, J.A.; Price, K.P.; Martinko, E.A.

    2001-01-01

    Six treatments of eastern Kansas tallgrass prairie - native prairie, hayed, mowed, grazed, burned and untreated - were studied to examine the biophysical effects of land management practices on grasslands. On each treatment, measurements of plant biomass, leaf area index, plant cover, leaf moisture and soil moisture were collected. In addition, measurements were taken of the Normalized Difference Vegetation Index (NDVI), which is derived from spectral reflectance measurements. Measurements were taken in mid-June, mid-July and late summer of 1990 and 1991. Multivariate analysis of variance was used to determine whether there were differences in the set of variables among treatments and years. Follow-up tests included univariate t-tests to determine which variables were contributing to any significant difference. Results showed a significant difference (p treatments in the composite of parameters during each of the months sampled. In most treatment types, there was a significant difference between years within each month. The univariate tests showed, however, that only some variables, primarily soil moisture, were contributing to this difference. We conclude that biomass and % plant cover show the best potential to serve as long-term indicators of grassland condition as they generally were sensitive to effects of different land management practices but not to yearly change in weather conditions. NDVI was insensitive to precipitation differences between years in July for most treatments, but was not in the native prairie. Choice of sampling time is important for these parameters to serve effectively as indicators.

  15. Prairie Change Analysis 1991-2008

    Data.gov (United States)

    Minnesota Department of Natural Resources — This dataset displays the results of a prairie/savanna change analysis study completed in May 2010. The area reviewed consists of 1,521 sites identified by Minnesota...

  16. Mixed

    Directory of Open Access Journals (Sweden)

    Pau Baya

    2011-05-01

    Full Text Available Remenat (Catalan (Mixed, "revoltillo" (Scrambled in Spanish, is a dish which, in Catalunya, consists of a beaten egg cooked with vegetables or other ingredients, normally prawns or asparagus. It is delicious. Scrambled refers to the action of mixing the beaten egg with other ingredients in a pan, normally using a wooden spoon Thought is frequently an amalgam of past ideas put through a spinner and rhythmically shaken around like a cocktail until a uniform and dense paste is made. This malleable product, rather like a cake mixture can be deformed pulling it out, rolling it around, adapting its shape to the commands of one’s hands or the tool which is being used on it. In the piece Mixed, the contortion of the wood seeks to reproduce the plasticity of this slow heavy movement. Each piece lays itself on the next piece consecutively like a tongue of incandescent lava slowly advancing but with unstoppable inertia.

  17. The effects of black-tailed prairie dogs on plant communities within a complex urban landscape: an ecological surprise?

    Science.gov (United States)

    Beals, Stower C; Hartley, Laurel M; Prevéy, Janet S; Seastedt, Timothy R

    2014-05-01

    Historically, prairie dogs (Cynomys spp.) have been considered essential keystone species of western United States grassland ecosystems because they provide unique services and increase vegetation community richness, evenness, and diversity. However, the effects of black-tailed prairie dogs (Cynomys ludovicianus) on lands adjacent to or surrounded by urban areas may not result in the same ecosystem benefits historically associated with their presence. An urban landscape presents prairie dogs with movement challenges unparalleled in natural landscapes, as well as suites of nonnative plant species that are more common in disturbed areas. This study examined a complex ecosystem where vegetation communities are being influenced by directional environmental change, and quantified the synergistic effects resulting from the protective management of a native keystone species. The data set for this analysis was comprised of 71 paired (occupied by prairie dogs vs. unoccupied) vegetation surveys and 156 additional unpaired surveys collected from around the city of Boulder, Colorado, USA for 14 yr. Linear mixed models were used to compare data from transects occupied and unoccupied by prairie dogs, as well as to evaluate the effect of prairie dog occupation duration. In the absence of prairie dogs, vegetation in this region exhibited declines in native grasses, no changes in introduced grasses, and increases in native and nonnative forbs and bare soil over the study interval. In the presence of prairie dogs, these observed directional changes were nearly all amplified at rates four to 10 times greater than when prairie dogs were absent. Areas in Boulder occupied by prairie dogs also had significantly lower richness, evenness, and diversity of plant species, compared to unoccupied areas. Analysis of plant functional groups revealed the significant reduction of perennial native grasses, as well as a significantly higher cover of introduced forbs in occupied areas. Prairie dogs

  18. A note on the effects of paddock size on the white clover content of swards grazed by sheep

    NARCIS (Netherlands)

    Wolf, de P.L.; Schulte, R.P.O.; Lantinga, E.A.

    2004-01-01

    The maintenance of a high white clover content in mixed swards under sheep grazing has been a challenge to date. This paper presents the results of an experiment in which the effect of the length of a grazing period on the botanical composition of a mixed sward was studied. Paddocks ranging in size

  19. Zooplankton grazing in a eutrophic lake: implications of diel vertical migration

    International Nuclear Information System (INIS)

    Lampert, W.; Taylor, B.E.

    1985-01-01

    During summer and fall, depth profiles of zooplankton community grazing were determined in situ during day and night in the Schoehsee, a small eutrophic lake. Labeled algae of two different sizes were mixed with the natural suspension of phytoplankton in a grazing chamber. A small blue-green alga (Synechococcus, 1 μm) was labeled with 32 P; a larger green alga (Scenedesmus, 4-15 μm) was labeled with 14 C. During summer, grazing in the upper 5 m was negligible during day but strong at night. Hence, algae grow relatively unimpeded by grazing during daytime but are harvested at night. Vertical and diel differences in grazing rates disappeared when the vertical migration ceased in fall. Selectivity of grazing was controlled by the zooplankton species composition. Eudiaptomus showed a strong preference for Scenedesmus. Daphnia showed a slight preference for Scenedesmus, but Ceriodaphnia preferred Synechococcus. Cyclopoid copepodites did not ingest the small blue-green. Because Daphnia and Eudiaptomus were dominant, grazing rates on larger cells were usually higher than grazing rates on the small cells. Negative electivity indices for scenedesmus occurred only when the biomass of large crustaceans was extremely low (near the surface, during day). Zooplankton biomass was the main factor controlling both vertical and seasonal variations in grazing. Highest grazing rates (65%/d) were measured during fall when zooplankton abundance was high. Because differential losses can produce substantial errors in the results, it was necessary to process the samples on the boat immediately after collection, without preservation

  20. Grazing incidence beam expander

    Energy Technology Data Exchange (ETDEWEB)

    Akkapeddi, P.R.; Glenn, P.; Fuschetto, A.; Appert, Q.; Viswanathan, V.K.

    1985-01-01

    A Grazing Incidence Beam Expander (GIBE) telescope is being designed and fabricated to be used as an equivalent end mirror in a long laser resonator cavity. The design requirements for this GIBE flow down from a generic Free Electron Laser (FEL) resonator. The nature of the FEL gain volume (a thin, pencil-like, on-axis region) dictates that the output beam be very small. Such a thin beam with the high power levels characteristic of FELs would have to travel perhaps hundreds of meters or more before expanding enough to allow reflection from cooled mirrors. A GIBE, on the other hand, would allow placing these optics closer to the gain region and thus reduces the cavity lengths substantially. Results are presented relating to optical and mechanical design, alignment sensitivity analysis, radius of curvature analysis, laser cavity stability analysis of a linear stable concentric laser cavity with a GIBE. Fabrication details of the GIBE are also given.

  1. Soil change induced by prairie dogs across three ecological sites

    Science.gov (United States)

    Prairie dogs (Cynomys spp.) can influence vegetation dynamics and landscape hydrology by altering soil properties, yet few studies have evaluated soil responses to prairie dog activities across a range of soil types. This study was conducted to quantify prairie dog effects on soil properties within...

  2. Lucerne varieties for continuous grazing

    DEFF Research Database (Denmark)

    Søegaard, Karen

    2012-01-01

    severe grazing with heifers in two cutting/grazing managements. Two new varieties, Verbena and Camporegio, and an older variety Luzelle were established in 2009 in pure stands and in two different mixtures with perennial ryegrass (Lolium perenne). Camporegio had the lowest yield, the lowest competitive...... strength, the lowest plant density in spring, and the density was most reduced during grazing. The results could not confirm significant differences between the new and the older varieties. The results for Luzelle were generally between Verbena and Camporegio. The varieties did not differ in herbage...

  3. Greenhouse effect gases sources and sinks (CO{sub 2}, CH{sub 4}, N{sub 2}O) in grasslands and reduction strategies. Greenhouse effect gases prairies. Final report of the second part of the project. April 2004; Sources et puits de gaz a effet de serre (CO{sub 2}, CH{sub 4}, N{sub 2}O) en prairie paturee et strategies de reduction. GES-Prairies. Rapport final de la seconde tranche du projet. Avril 2004

    Energy Technology Data Exchange (ETDEWEB)

    Soussana, J.F

    2004-04-15

    The project 'GES-Prairies' (Greenhouse Gases - Grasslands) had two main objectives: 1. To measure more accurately the fluxes of CO{sub 2}, CH{sub 4} and N{sub 2}O of French grasslands and determine the greenhouse gas (GHG) balance of these areas. 2. To calculate the net GHG emissions of cattle production farms and finally to propose and evaluate some management scenarios leading to a reduction of GHG emissions. This project deals with three different spatial scales: the field scale, the farm scale and finally, the regional scale. At the field scale, during two years, fluxes of CO{sub 2}, CH{sub 4} and N{sub 2}O were measured in a mid-mountain permanent grassland, previously managed intensively by cutting and grazing (Laqueuille, Auvergne, France). Results from the first complete year of measurements show that the extensification process (reduction of the stocking rate and stopping N fertilization) allows to stock more carbon in the ecosystem. At the farm scale, We developed a model (FARMSIM, coupled to PASIM) able to simulate the GHG balance of a livestock farm. FARMSIM has been tested with data obtained from a mixed livestock farm in Lorraine (dairy and meat production, annual average stocking rate = 1.3 LU ha{sup -1}) of 100 ha (including 76 ha of grasslands and 21 of annual crops). The results indicate a net emission of 175 t equivalent C-CO{sub 2} for this farm. If expressed per unit of product, it represents 1.34 t equivalent C-CO{sub 2} per LU and per year or 0.54 kg CO{sub 2} per kg of milk and per year. At the regional scale/. The PASIM model has been used to simulate the European grasslands with a spatial resolution of 1' (about 200 * 200 km). For each grid cell, a sensibility analysis allowed to determine the N application which correspond to 30% of the N application that would maximize the annual yield of the pasture. Simulation runs on mixed systems (combining grazing and cutting) show that almost one half of the grassland area is, on

  4. State of the prairies of marine grasses

    International Nuclear Information System (INIS)

    Barrios, Lina M; Gomez, Diana I

    2002-01-01

    At the end of the year 2000, INVEMAR gave beginning to the project Distribution, it structures and classification of the prairies of marine flowering in the Colombian Caribbean, guided to characterize ecological and environmentally the ecosystems in this Colombian sector, particularly as for its distribution, extension, structures, associate biota and intervention degree. The above-mentioned like answer to the lack of information that was presented to the date in almost all the levels (line bases and ecology) for this ecosystem, required to implement monitoring programs and to adopt conservation strategies for the same one. The information that is presented is based primarily on the results obtained during the execution of the project in mention. An diagnostic is done, a characterization of the prairies, epiphytes covering, associate fauna and it structures of the prairies

  5. Transitions and coexistence along a grazing gradient in the Eurasian steppe

    Science.gov (United States)

    Ren, Haiyan; Taube, Friedelm; Zhang, Yingjun; Bai, Yongfei; Hu, Shuijin

    2017-04-01

    Ecological resilience theory has often been applied to explain species coexistence and range condition assessment of various community states and to explicate the dynamics of ecosystems. Grazing is a primary disturbance that can alter rangeland resilience by causing hard-to-reverse transitions in grasslands. Yet, how grazing affects the coexistence of plant functional group (PFG) and transition remains unclear. We conducted a six-year grazing experiment in a typical steppe of Inner Mongolia, using seven grazing intensities (0, 1.5, 3.0, 4.5, 6.0, 7.5 and 9.0 sheep/ hectare) and two grazing systems (i.e. a continuous annual grazing as in the traditional grazing system, and a mixed grazing system combining grazing and haymaking), to examine grazing effects on plant functional group shifts and species coexistence in the semi-arid grassland system. Our results indicate that the relative richness of dominant bunchgrasses and forbs had a compensatory coexistence at all grazing intensities, and the richness of rhizomatous grasses fluctuated but was persistent. The relative productivity of dominant bunchgrasses and rhizomatous grasses had compensatory interactions with grazing intensity and grazing system. Dominant bunchgrasses and rhizomatous grasses resist grazing effects by using their dominant species functional traits: high specific leaf area and low leaf nitrogen content. Our results suggest that: 1. Stabilizing mechanisms beyond grazing management are more important in determining plant functional group coexistence and ecological resilience. 2. Plant functional group composition is more important in influencing ecosystem functioning than diversity. 3. Ecosystem resilience at a given level is related to the biomass of dominant PFG, which is determined by a balanced shift between dominant species biomass. The relatively even ecosystem resilience along the grazing gradient is attributed to the compensatory interactions of dominant species in their biomass variations

  6. A comparison of some methods used to estimate the grazing capacity of a game ranch in Northern Province, South Africa

    Directory of Open Access Journals (Sweden)

    A.G. Schmidt

    1995-08-01

    Full Text Available The grazing capacity of a game ranch in Northern Province was estimated in a number of different ways using rainfall and herbaceous composition and phytomass data. The results indicate that the grazing capacity under the present environmental conditions should be approximately 50 of the recommended agricultural grazer stocking rate. This is in agreement with recent literature, indicating that the methods used should be suitable for determining a first approximation of grazing capacity in the mixed bushveld of Northern Province.

  7. Invasive plants affect prairie soil biology

    Science.gov (United States)

    Non-native or exotic plants often cause ecological and environmental damage in ecosystems where they invade and become established. These invasive plants may be the most serious threat to plant diversity in prairies, especially those in scattered remnants, which may be particularly vulnerable to rap...

  8. Timber resource of Minnesota's Prairie unit, 1977.

    Science.gov (United States)

    Jerold T. Hahn; W. Brad Smith

    1980-01-01

    The fourth inventory of Minnesota's Prairie Unit shows that although commercial forest area decreased 31.7% between 1962 and 1977, growing-stock volume increased 22%. This report gives statistical highlights and contains detailed tables of forest area as well as timber volume, growth, mortality, ownership, and use.

  9. Timber resource of Missouri's Prairie, 1972.

    Science.gov (United States)

    Jerold T. Hahn; Alexander Vasilevsky

    1975-01-01

    The third timber inventory of Missouri's Prairie Forest Survey Unit shows substantial declines in both growing-stock and sawtimber volumes between 1959 and 1972. Commercial forest area declined by one-fifth. Presents highlights and statistics on forest area and timber volume, growth, mortality, ownership, and use in 1972.

  10. Grazing Incidence Optics Technology

    Science.gov (United States)

    Ramsey, Brian; Smith, W. Scott; Gubarev, Mikhail; McCracken, Jeff

    2015-01-01

    This project is to demonstrate the capability to directly fabricate lightweight, high-resolution, grazing-incidence x-ray optics using a commercially available robotic polishing machine. Typical x-ray optics production at NASA Marshall Space Flight Center (MSFC) uses a replication process in which metal mirrors are electroformed on to figured and polished mandrels from which they are later removed. The attraction of this process is that multiple copies can be made from a single master. The drawback is that the replication process limits the angular resolution that can be attained. By directly fabricating each shell, errors inherent in the replication process are removed. The principal challenge now becomes how to support the mirror shell during all aspects of fabrication, including the necessary metrology to converge on the required mirror performance specifications. This program makes use of a Zeeko seven-axis computer-controlled polishing machine (see fig. 1) and supporting fabrication, metrology, and test equipment at MSFC. The overall development plan calls for proof-of-concept demonstration with relatively thick mirror shells (5-6 mm, fig. 2) which are straightforward to support and then a transition to much thinner shells (2-3 mm), which are an order of magnitude thinner than those used for Chandra. Both glass and metal substrates are being investigated. Currently, a thick glass shell is being figured. This has enabled experience to be gained with programming and operating the polishing machine without worrying about shell distortions or breakage. It has also allowed time for more complex support mechanisms for figuring/ polishing and metrology to be designed for the more challenging thinner shells. These are now in fabrication. Figure 1: Zeeko polishing machine.

  11. A comparison of native tallgrass prairie and plains bluestem forage systems for cow-calf production in the southern great plains.

    Science.gov (United States)

    Coleman, S W; Phillips, W A; Volesky, J D; Buchanan, D

    2001-07-01

    The objective of this study was to compare an introduced warm-season perennial grass (plains bluestem, Bothriochloa ischaemum) to native tallgrass prairie for cow-calf production. Three systems were used, two based on tallgrass prairie with two different forms of protein supplementation and one based on plains bluestem as the primary forage. The systems were as follows: 1) native tallgrass prairie with pelleted oilseed meal as the winter protein supplement (native-control); 2) native tallgrass prairie with limited access to wheat pasture as the winter protein supplement (native-wheat); and 3) plains bluestem with limited access to wheat pasture as the protein supplement (bluestem-wheat). Oilseed meal protein supplements were fed twice weekly. Cows grazing wheat pasture were allowed 6 h of grazing twice weekly. Ninety-nine cows per year were used over the 3-yr study. Cows were sired by either Charolais, Gelbvieh, Angus, or Hereford bulls out of commercial Angus-Hereford dams. Calves were sired by Simmental bulls. Calving and weaning rate increased over time but did not differ among systems or breed types. System did not influence the size or body condition score of cows or the performance of calves, but changes in the weight and condition scores of cows were greater on either native system than on the bluestem-wheat system. Cows from Charolais and Gelbvieh bulls were taller (P < 0.05), and heavier (P < 0.05), and weaned heavier (P < 0.05) calves than cows from Angus or Hereford bulls. The weight of cows on the bluestem-wheat system tended to decrease over time, whereas cows grazing on the native systems tended to gain weight over time. The native-control system was the most profitable system based on cow production. If excess hay produced from the bluestem-wheat system was sold as a cash crop, then this system was the most profitable. In general, we conclude that limit-grazing wheat pasture is a viable alternative to oilseed meal as protein supplement for wintering

  12. Feeding ecology of arctic-nesting sandpipers during spring migration through the prairie pothole region

    Science.gov (United States)

    Eldridge, J.L.; Krapu, G.L.; Johnson, D.H.

    2009-01-01

    We evaluated food habits of 4 species of spring-migrant calidrid sandpipers in the Prairie Pothole Region (PPR) of North Dakota. Sandpipers foraged in several wetland classes and fed primarily on aquatic dipterans, mostly larvae, and the midge family Chironomidae was the primary food eaten. Larger sandpiper species foraged in deeper water and took larger larvae than did smaller sandpipers. The diverse wetland habitats that migrant shorebirds use in the PPR suggest a landscape-level approach be applied to wetland conservation efforts. We recommend that managers use livestock grazing and other tools, where applicable, to keep shallow, freshwater wetlands from becoming choked with emergent vegetation limiting chironomid production and preventing shorebird use.

  13. Multisensor sampling of pelagic ecosystem variables in a coastal environment to estimate zooplankton grazing impact

    Science.gov (United States)

    Sutton, Tracey; Hopkins, Thomas; Remsen, Andrew; Burghart, Scott

    2001-01-01

    Sampling was conducted on the west Florida continental shelf ecosystem modeling site to estimate zooplankton grazing impact on primary production. Samples were collected with the high-resolution sampler, a towed array bearing electronic and optical sensors operating in tandem with a paired net/bottle verification system. A close biological-physical coupling was observed, with three main plankton communities: 1. a high-density inshore community dominated by larvaceans coincident with a salinity gradient; 2. a low-density offshore community dominated by small calanoid copepods coincident with the warm mixed layer; and 3. a high-density offshore community dominated by small poecilostomatoid and cyclopoid copepods and ostracods coincident with cooler, sub-pycnocline oceanic water. Both high-density communities were associated with relatively turbid water. Applying available grazing rates from the literature to our abundance data, grazing pressure mirrored the above bio-physical pattern, with the offshore sub-pycnocline community contributing ˜65% of grazing pressure despite representing only 19% of the total volume of the transect. This suggests that grazing pressure is highly localized, emphasizing the importance of high-resolution sampling to better understand plankton dynamics. A comparison of our grazing rate estimates with primary production estimates suggests that mesozooplankton do not control the fate of phytoplankton over much of the area studied (<5% grazing of daily primary production), but "hot spots" (˜25-50% grazing) do occur which may have an effect on floral composition.

  14. A Prairie Dog Abatement Program in San Juan County, Utah

    OpenAIRE

    Messmer, Terry A.; Keyes, Jim; McDonald, Roy

    1993-01-01

    Four species of prairie dogs are native to the plains and plateaus of the western United States. The most abundant and widely distributed of these is the blacktailed prairie dog, (Cynomys ludovicianus). This species has been a frequent topic of discussion at previous Great Plains Wildlife Damage Control workshops. Black-tailed prairie dog ecology and management was the topic of a panel discussion held at the Fifth Great Plains Wildlife Damage Control Workshop, in Lincoln, Nebraska (Timm and J...

  15. Ecology of grazing lawns in Africa

    CSIR Research Space (South Africa)

    Hempson, GP

    2014-09-01

    Full Text Available otherwise outcompete lawn species for light. Regular grazing that prevents shading and maintains sward quality is thus the cornerstone of grazing lawn dynamics. The strong interplay between abiotic conditions and disturbance factors, which are central...

  16. Livestock grazing, wildlife habitat, and rangeland values

    Science.gov (United States)

    Paul R. Krausman; David E. Naugle; Michael R. Frisina; Rick Northrup; Vernon C. Bleich; William M. Block; Mark C. Wallace; Jeffrey D. Wright

    2009-01-01

    Livestock managers make and implement grazing management decisions to achieve a variety of objectives including livestock production, sustainable grazing, and wildlife habitat enhancement. Assessed values of grazing lands and ranches are often based on aesthetics and wildlife habitat or recreational values, which can exceed agricultural values, thus providing...

  17. 50 CFR 35.9 - Livestock grazing.

    Science.gov (United States)

    2010-10-01

    ... 50 Wildlife and Fisheries 6 2010-10-01 2010-10-01 false Livestock grazing. 35.9 Section 35.9... NATIONAL WILDLIFE REFUGE SYSTEM WILDERNESS PRESERVATION AND MANAGEMENT General Rules § 35.9 Livestock grazing. (a) The grazing of livestock, where established prior to the date of legislation which designates...

  18. 7 CFR 760.305 - Eligible grazing losses.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 7 2010-01-01 2010-01-01 false Eligible grazing losses. 760.305 Section 760.305... grazing losses. (a) A grazing loss due to drought is eligible for LFP only if the grazing loss for the... period for the specific type of grazing land or pastureland for the county.) (b) A grazing loss is not...

  19. Prairies Water Management on Corps Lands

    Science.gov (United States)

    2009-02-01

    infiltration, autogenic mechanisms can lead to the recovery of essential soil processes. The Role of Organic Matter in Soil Formation. In a prairie...management in EP-1130-2-540 (USACE 2005), and does not have a fire management training program in place (USACE 2008). Some Corps resource managers...are trained and partner with other entities to conduct prescribed burns on Corps grasslands. However, prescribed burning as a management strategy is

  20. Revegetation of wellsite disturbances on Fescue Prairie in east-central Alberta

    International Nuclear Information System (INIS)

    Woosaree, J.; Puhl, M.

    1999-01-01

    It has been observed that past methods of revegetating disturbed land in Alberta by using commercially-available species of grasses has had limited success in terms of biodiversity, the reason being that commercial forage species are highly competitive, and as such not only prevented the original prairie species from returning to reclaimed sites, but in some cases they have migrated from reclaimed sites and invaded surrounding native prairie. Alfalfa, crested wheatgrass, Kentucky bluegrass and Canada bluegrass are believed to be the most invasive of these commercially available species. Because their use in the past has resulted in landscape fragmentation, they are not recommended for use on wellsites located on native prairie. The limited mix of available native grass cultivars also have had limited success in increasing species diversity. Cross seeding has been suggested as one method for reducing the effect of inter-specific competition on the species emergence. However, the general view of government and industry is that improved methods of revegetation of wellsite disturbances and new guidelines for determining reclamation success are required to establish more ecologically compatible plant communities on well site disturbances 4 refs., 1 tab., 3 figs

  1. Arbuscular common mycorrhizal networks mediate intra- and interspecific interactions of two prairie grasses.

    Science.gov (United States)

    Weremijewicz, Joanna; da Silveira Lobo O'Reilly Sternberg, Leonel; Janos, David P

    2018-01-01

    Arbuscular mycorrhizal fungi form extensive common mycorrhizal networks (CMNs) that may interconnect neighboring root systems of the same or different plant species, thereby potentially influencing the distribution of limiting mineral nutrients among plants. We examined how CMNs affected intra- and interspecific interactions within and between populations of Andropogon gerardii, a highly mycorrhiza dependent, dominant prairie grass and Elymus canadensis, a moderately dependent, subordinate prairie species. We grew A. gerardii and E. canadensis alone and intermixed in microcosms, with individual root systems isolated, but either interconnected by CMNs or with CMNs severed weekly. CMNs, which provided access to a large soil volume, improved survival of both A. gerardii and E. canadensis, but intensified intraspecific competition for A. gerardii. When mixed with E. canadensis, A. gerardii overyielded aboveground biomass in the presence of intact CMNs but not when CMNs were severed, suggesting that A. gerardii with intact CMNs most benefitted from weaker interspecific than intraspecific interactions across CMNs. CMNs improved manganese uptake by both species, with the largest plants receiving the most manganese. Enhanced growth in consequence of improved mineral nutrition led to large E. canadensis in intact CMNs experiencing water-stress, as indicated by 13 C isotope abundance. Our findings suggest that in prairie plant communities, CMNs may influence mineral nutrient distribution, water relations, within-species size hierarchies, and between-species interactions.

  2. Chicago's Columbus Park: The Prairie Idealized. Teaching with Historic Places.

    Science.gov (United States)

    Bachrach, Julia Sniderman; Nathan, Jo Ann

    Twenty-four year old Jens Jensen came to the United States, settled in Chicago (Illinois), and promptly fell in love with the Midwest's prairie landscape. Although some thought that prairie was boring, monotonous, and ordinary, Jensen saw great beauty in the tree-filled groves, long winding rivers, natural rock formations and waterfalls, and the…

  3. 78 FR 17224 - Environmental Impact Statement; Proposed South Puget Sound Prairie Habitat Conservation Plan...

    Science.gov (United States)

    2013-03-20

    ... sizable portion of South Puget Sound Prairie habitat is located in the urban-rural interface and in the...-FF01E00000] Environmental Impact Statement; Proposed South Puget Sound Prairie Habitat Conservation Plan... permit application would be associated the South Puget Sound Prairie Habitat Conservation Plan (Prairie...

  4. Restoration and winter avian use of isolated prairies in eastern Texas

    Science.gov (United States)

    D. Craig Rudolph; Dave E. Plair; Dan Jones; J. Howard Williamson; Clifford E. Shackelford; Richard R. Schaefer; Joshua B. Pierce

    2014-01-01

    Numerous isolated prairies exist, or existed, on the West Gulf Coastal Plain east of the main distribution of the prairie ecosystem. Changing land-use patterns and suppression of wildfire have destroyed almost all of these small prairie occurrences. Intensified restoration and management of degraded prairie habitat on the Sam Houston National Forest in southeastern...

  5. Prairie Monitoring Protocol Development: North Coast and Cascades Network

    Science.gov (United States)

    McCoy, Allen; Dalby, Craig

    2009-01-01

    The purpose of the project was to conduct research that will guide development of a standard approach to monitoring several components of prairies within the North Coast and Cascades Network (NCCN) parks. Prairies are an important element of the natural environment at many parks, including San Juan Island National Historical Park (NHP) and Ebey's Landing National Historical Reserve (NHR). Forests have been encroaching on these prairies for many years, and so monitoring of the prairies is an important resource issue. This project specifically focused on San Juan Island NHP. Prairies at Ebey's Landing NHR will be monitored in the future, but that park was not mapped as part of this prototype project. In the interest of efficiency, the Network decided to investigate two main issues before launching a full protocol development effort: (1) the imagery requirements for monitoring prairie components, and (2) the effectiveness of software to assist in extracting features from the imagery. Several components of prairie monitoring were initially identified as being easily tracked using aerial imagery. These components included prairie/forest edge, broad prairie composition (for example, shrubs, scattered trees), and internal exclusions (for example, shrubs, bare ground). In addition, we believed that it might be possible to distinguish different grasses in the prairies if the imagery were of high enough resolution. Although the areas in question at San Juan Island NHP are small enough that mapping on the ground with GPS (Global Positioning System) would be feasible, other applications could benefit from aerial image acquisition on a regular, recurring basis and thereby make the investment in aerial imagery worthwhile. The additional expense of orthorectifying the imagery also was determined to be cost-effective.

  6. Greenhouse effect gases sources and sinks (CO2, CH4, N2O) in grasslands and reduction strategies. Greenhouse effect gases prairies. Final report of the second part of the project. April 2004

    International Nuclear Information System (INIS)

    Soussana, J.F.

    2004-04-01

    The project 'GES-Prairies' (Greenhouse Gases - Grasslands) had two main objectives: 1. To measure more accurately the fluxes of CO 2 , CH 4 and N 2 O of French grasslands and determine the greenhouse gas (GHG) balance of these areas. 2. To calculate the net GHG emissions of cattle production farms and finally to propose and evaluate some management scenarios leading to a reduction of GHG emissions. This project deals with three different spatial scales: the field scale, the farm scale and finally, the regional scale. At the field scale, during two years, fluxes of CO 2 , CH 4 and N 2 O were measured in a mid-mountain permanent grassland, previously managed intensively by cutting and grazing (Laqueuille, Auvergne, France). Results from the first complete year of measurements show that the extensification process (reduction of the stocking rate and stopping N fertilization) allows to stock more carbon in the ecosystem. At the farm scale, We developed a model (FARMSIM, coupled to PASIM) able to simulate the GHG balance of a livestock farm. FARMSIM has been tested with data obtained from a mixed livestock farm in Lorraine (dairy and meat production, annual average stocking rate = 1.3 LU ha -1 ) of 100 ha (including 76 ha of grasslands and 21 of annual crops). The results indicate a net emission of 175 t equivalent C-CO 2 for this farm. If expressed per unit of product, it represents 1.34 t equivalent C-CO 2 per LU and per year or 0.54 kg CO 2 per kg of milk and per year. At the regional scale/. The PASIM model has been used to simulate the European grasslands with a spatial resolution of 1' (about 200 * 200 km). For each grid cell, a sensibility analysis allowed to determine the N application which correspond to 30% of the N application that would maximize the annual yield of the pasture. Simulation runs on mixed systems (combining grazing and cutting) show that almost one half of the grassland area is, on average, used for cutting. These simulations predict N 2 O

  7. Oxytocin reduces alcohol consumption in prairie voles.

    Science.gov (United States)

    Stevenson, J R; Wenner, S M; Freestone, D M; Romaine, C C; Parian, M C; Christian, S M; Bohidar, A E; Ndem, J R; Vogel, I R; O'Kane, C M

    2017-10-01

    Alcohol use disorder (AUD) negatively affects millions of people every year in the United States, and effective treatments for AUD are still needed. The neuropeptide oxytocin has shown promise for reducing alcohol drinking in mice and rats. Because oxytocin also plays a key role in complex prosocial behaviors like bonding and attachment, we tested the effect of oxytocin on alcohol drinking in prairie voles, a species that both consumes high amounts of alcohol and forms oxytocin dependent social bonds in a manner similar to humans. Oxytocin treatment (1.0, 3.0, and 10.0mg/kg, i.p.) reduced alcohol consumption in male and female prairie voles in animals that had access to 15% ethanol vs water every other day for 12 alcohol drinking sessions. In animals with continuous access to 15% alcohol and water, oxytocin (3.0mg/kg) reduced alcohol consumption only in the first hour of access after treatment, with no significant effects on consumption over the 24-hr period. In an open field locomotor test, oxytocin (1.0, 3.0, and 10.0mg/kg, i.p.) did not affect overall locomotor activity; however, ethanol (2g/kg, i.p.) increased locomotor activity in males and females, and produced anxiolytic effects (increased time in the center of an open field) in females only. Because prairie voles have been shown to match the alcohol consumption of their cage mate, we evaluated the relationship between cage mates' alcohol drinking. There was an overall pattern of social facilitation (consumption by one cage mate predicted consumption by the other cage mate); however, we found significant individual differences across cages in which many cages did not show significant matching, and, in some cases one cage mate's consumption negatively predicted the other cage mate's consumption. Overall, our data provide support for the potential of oxytocin as a treatment to reduce alcohol consumption. Copyright © 2017 Elsevier Inc. All rights reserved.

  8. Grass composition and rangeland condition of the major grazing ...

    African Journals Online (AJOL)

    One area represented lightly grazed government ranches or parks which were used as benchmarks, another area represented the seasonal grazing areas with an intermediate grazing pressure and the remaining were the heavily grazed roadsides, lakeshores and other communal grazing lands. The range condition ...

  9. The grazing pattern of Muturu cattle under range system | Nweze ...

    African Journals Online (AJOL)

    Eighty Muturu cattle were grazed on rangeland, twice daily for two years to determine their grazing pattern. Twenty bulls and cows each between two to four years and forty calves between one to three months were used. The field grazing time (FGT), active grazing time (GT) and grazing travel time (GTT) were monitored.

  10. Produção de forragem em pastagens consorciadas com diferentes leguminosas sob pastejo rotacionado = Forage production in pasture-based systems mixed with different legumes under rotational grazing

    Directory of Open Access Journals (Sweden)

    Edilene Steinwandter

    2009-04-01

    Full Text Available O objetivo desta pesquisa foi avaliar dois sistemas forrageiros, constituídos por capim-elefante, azevém, trevo branco ou amendoim forrageiro e espécies de crescimento espontâneo, quanto às taxas de acúmulo e de desaparecimento de MS. Para avaliação utilizaram-se quatro piquetes, com 0,25 ha cada um, com capim-elefante estabelecido em linhas afastadas a cada 4 m. No período hibernal, entre as linhas do capim-elefante, fez-se o estabelecimento do azevém; em dois piquetes foi semeado o trevo branco e nos demais se preservou o amendoim forrageiro. O delineamento experimental utilizado foi inteiramente casualizado. Para a determinação das taxas de acúmulo e de desaparecimento de MS, avaliaram-se as massas de forragem de pré e pós-pastejo. Foram avaliadas a composição botânica e estrutural da pastagem e a lotação. Na média, as taxas de acúmulo e dedesaparecimento da MS e a lotação foram de 47,29 kg de MS ha-1 dia-1; 3,24% e 3,01 UA ha-1 e de 53,16 kg de MS ha-1 dia-1; 3,45% e 3,48 UA ha-1 para os sistemas constituídos por trevo branco e por amendoim forrageiro, respectivamente. Considerando-se a taxa de acúmulo deMS, a MS desaparecida e a lotação, os resultados demonstram melhores resultados para o sistema forrageiro constituído pelo amendoim forrageiro.The objective of this research was to evaluate two pasture-based systems, with elephantgrass, ryegrass, white clover or forage peanut and spontaneous growth species about the accumulation rate and of disappearance of forage mass. The elephantgrass was established in rows with a distance of 4 m between rows. In the cool season, ryegrass was planted between rows of elephantgrass; white clover wassowed,in two paddocks, and in the other two the forage peanut was preserved. The experimental design was completely randomized. In order to stipulate the accumulation rate and of disappearance of forage mass, the pre- and post-graze forage mass were evaluated.The botanical and

  11. Drought, Climate Change and the Canadian Prairies

    Science.gov (United States)

    Stewart, R. E.

    2010-03-01

    The occurrence of drought is a ubiquitous feature of the global water cycle. Such an extreme does not necessarily lead to an overall change in the magnitude of the global water cycle but it of course affects the regional cycling of water. Droughts are recurring aspects of weather and climate extremes as are floods and tornadoes, but they differ substantially since they have long durations and lack easily identified onsets and terminations. Drought is a relatively common feature of the North American and Canadian climate system and all regions of the continent are affected from time-to-time. However, it tends to be most common and severe over the central regions of the continent. The Canadian Prairies are therefore prone to drought. Droughts in the Canadian Prairies are distinctive in North America. The large scale atmospheric circulations are influenced by blocking from intense orography to the west and long distances from all warm ocean-derived atmospheric water sources; growing season precipitation is generated by a highly complex combination of frontal and convective systems; seasonality is severe and characterized by a relatively long snow-covered and short growing seasons; local surface runoff is primarily produced by snowmelt water; there is substantial water storage potential in the poorly drained, post-glacial topography; and aquifers are overlain by impermeable glacial till, but there are also important permeable aquifers. One example of Prairie drought is the recent one that began in 1999 with cessation of its atmospheric component in 2004/2005 and many of its hydrological components in 2005. This event produced the worst drought for at least a hundred years in parts of the Canadian Prairies. Even in the dust bowl of the 1930s, no single year over the central Prairies were drier than in 2001. The drought affected agriculture, recreation, tourism, health, hydro-electricity, and forestry in the Prairies. Gross Domestic Product fell some 5.8 billion and

  12. Southern marl prairies conceptual ecological model

    Science.gov (United States)

    Davis, S.M.; Loftus, W.F.; Gaiser, E.E.; Huffman, A.E.

    2005-01-01

    About 190,000 ha of higher-elevation marl prairies flank either side of Shark River Slough in the southern Everglades. Water levels typically drop below the ground surface each year in this landscape. Consequently, peat soil accretion is inhibited, and substrates consist either of calcitic marl produced by algal periphyton mats or exposed limestone bedrock. The southern marl prairies support complex mosaics of wet prairie, sawgrass sawgrass (Cladium jamaicense), tree islands, and tropical hammock communities and a high diversity of plant species. However, relatively short hydroperiods and annual dry downs provide stressful conditions for aquatic fauna, affecting survival in the dry season when surface water is absent. Here, we present a conceptual ecological model developed for this landscape through scientific concensus, use of empirical data, and modeling. The two major societal drivers affecting the southern marl prairies are water management practices and agricultural and urban development. These drivers lead to five groups of ecosystem stressors: loss of spatial extent and connectivity, shortened hydroperiod and increased drought severity, extended hydroperiod and drying pattern reversals, introduction and spread of non-native trees, and introduction and spread of non-native fishes. Major ecological attributes include periphyton mats, plant species diversity and community mosaic, Cape Sable seaside sparrow (Ammodramus maritimus mirabilis), marsh fishes and associated aquatic fauna prey base, American alligator (Alligator mississippiensis), and wading bird early dry season foraging. Water management and development are hypothesized to have a negative effect on the ecological attributes of the southern marl prairies in the following ways. Periphyton mats have decreased in cover in areas where hydroperiod has been significantly reduced and changed in community composition due to inverse responses to increased nutrient availability. Plant species diversity and

  13. Sylvatic plague vaccine and management of prairie dogs

    Science.gov (United States)

    Rocke, Tonie E.

    2012-01-01

    Scientists at the USGS National Wildlife Health Center (NWHC), in collaboration with colleagues at the University of Wisconsin (UW), have developed a sylvatic plague vaccine that shows great promise in protecting prairie dogs against plague (Mencher and others, 2004; Rocke and others, 2010). Four species of prairie dogs reside in the United States and Canada, and all are highly susceptible to plague and regularly experience outbreaks with devastating losses. Along with habitat loss and poisoning, plague has contributed to a significant historical decline in prairie dog populations. By some estimates, prairie dogs now occupy only 1 to 2 percent of their former range (Proctor and others, 2006), with prairie dog colonies being now much smaller and fragmented than they were historically, making individual colonies more vulnerable to elimination by plague (Antolin and others, 2002). At least one species, the Utah prairie dog (Cynomys parvidens) is listed by the U.S. Fish and Wildlife Service (FWS) as "threatened." Controlling plague is a vital concern for ongoing management and conservation efforts for prairie dogs. Current efforts to halt the spread of plague in prairie dog colonies typically rely on dusting individual prairie dog burrows with pesticides to kill plague-infected fleas. Although flea-control insecticides, such as deltamethrin, are useful in stopping plague outbreaks in these prairie dog colonies, dusting of burrows is labor intensive and time consuming and may affect other insects and arthropods. As an alternative approach, NWHC and UW scientists developed a sylvatic plague vaccine (SPV) for prairie dogs that can be delivered via oral bait. Laboratory studies have shown that consumption of this vaccine-laden bait by different prairie dog species results in significant protection against plague infection that can last for at least 9 months (Rocke and others, 2010; Rocke, unpublished). Work has now shifted to optimizing baits and distribution methods for

  14. Grazing incidence diffraction : A review

    Energy Technology Data Exchange (ETDEWEB)

    Gilles, B [LTPCM, ENSEEG. St. Martin d` Heres. (France)

    1996-09-01

    Different Grazing Incidence Diffraction (GID) methods for the analysis of thin films and multilayer structures are reviewed in three sections: the reflectivity is developed in the first one, which includes the non-specular diffuse scattering. The second one is devoted to the extremely asymmetric Bragg diffraction and the third one to the in-plane Bragg diffraction. Analytical formulations of the scattered intensities are developed for each geometry, in the framework of the kinetical analysis as well as the dynamical theory. Experimental examples are given to illustrate the quantitative possibility of the GID techniques.

  15. Developing a framework for evaluating tallgrass prairie reconstruction methods and management

    Science.gov (United States)

    Larson, Diane L.; Ahlering, Marissa; Drobney, Pauline; Esser, Rebecca; Larson, Jennifer L.; Viste-Sparkman, Karen

    2018-01-01

    The thousands of hectares of prairie reconstructed each year in the tallgrass prairie biome can provide a valuable resource for evaluation of seed mixes, planting methods, and post-planting management if methods used and resulting characteristics of the prairies are recorded and compiled in a publicly accessible database. The objective of this study was to evaluate the use of such data to understand the outcomes of reconstructions over a 10-year period at two U.S. Fish and Wildlife Service refuges. Variables included number of species planted, seed source (combine-harvest or combine-harvest plus hand-collected), fire history, and planting method and season. In 2015 we surveyed vegetation on 81 reconstructions and calculated proportion of planted species observed; introduced species richness; native species richness, evenness and diversity; and mean coefficient of conservatism. We conducted exploratory analyses to learn how implied communities based on seed mix compared with observed vegetation; which seeding or management variables were influential in the outcome of the reconstructions; and consistency of responses between the two refuges. Insights from this analysis include: 1) proportion of planted species observed in 2015 declined as planted richness increased, but lack of data on seeding rate per species limited conclusions about value of added species; 2) differing responses to seeding and management between the two refuges suggest the importance of geographic variability that could be addressed using a public database; and 3) variables such as fire history are difficult to quantify consistently and should be carefully evaluated in the context of a public data repository.

  16. Herbage intake by grazing dairy cows

    NARCIS (Netherlands)

    Meijs, J.A.C.

    1981-01-01

    An extensive review of the literature is given of
    - nine possible methods for estimating herbage intake by grazing ruminants, with special attention to the sward-cutting and indirect animal methods
    - the factors determining the herbage intake by grazing ruminants.

    The

  17. 75 FR 29572 - Information Collection; Grazing Management

    Science.gov (United States)

    2010-05-26

    ... Control Number 1004-0019] Information Collection; Grazing Management AGENCY: Bureau of Land Management... submitted an information collection request to the Office of Management and Budget (OMB) for a 3-year... INFORMATION: Title: Grazing Management (43 CFR 4120). OMB Number: 1004-0019. Forms: 4120-6 (Cooperative Range...

  18. Carcass Search & Recovery Guidelines for Black Tailed Prairie Dogs

    Science.gov (United States)

    The availability of dead or intoxicated prairie dogs above ground will be monitored, recorded and these carcasses will be properly disposed of, in accordance with the procedures described on this page.

  19. NPP Grassland: Konza Prairie, USA, 1984-1990, R1

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set contains three ASCII files (.txt format). Two files contain above-ground biomass and productivity data for a humid temperate tall-grass prairie...

  20. Two decades of prairie restoration at Fermilab, Batavia, Illinois

    Energy Technology Data Exchange (ETDEWEB)

    Betz, R.F. [Northeastern Illinois Univ., Chicago, IL (United States); Lootens, R.J.; Becker, M.K. [Fermi National Accelerator Lab., Batavia, IL (United States)

    1996-12-31

    Successional Restoration is the method being used to restore the prairie at Fermilab on the former agricultural fields. This involves an initial planting, using aggressive species that have wide ecological tolerances which will grow well on abandoned agricultural fields. Collectively, these species are designated as the prairie matrix. The species used for this prairie matrix compete with and eventually eliminate most weedy species. They also provide an adequate fuel load capable of sustaining a fire within a few years after a site has been initially planted. Associated changes in the biological and physical structure of the soil help prepare the way for the successful introduction of plants of the later successional species. Only after the species of the prairie matrix are well established, is the species diversity increased by introducing species with narrower ecological tolerances. These species are thus characteristic of the later successional stages.

  1. Public knowledge and perceptions of black-tailed prairie dogs

    Science.gov (United States)

    Lamb, B.L.; Cline, K.

    2003-01-01

    Black-tailed prairie dogs (Cynomys ludovicianus) historically occupied an 11-state region of the United States. We surveyed 1,900 residents (response rate 56%) of this region to understand citizen knowledge and perceptions about prairie dogs and their management. Those who have direct experience - e.g., those who live very close to prairie dog colonies or know the location of the nearest colony - have higher levels of knowledge. A significantly higher level of knowledge was documented among those who were politically active when compared with the general public. Those who found environmental issues difficult to understand were associated with lower knowledge. People with direct experience were likely to hold negative views, whereas those holding environmentalist values were likely to express positive attitudes toward the species. Although those with higher education reported more knowledge, there was no link between a person's level of knowledge and perceptions of prairie dog management.

  2. Brant Prairie : Union Gas customer service centre, Brantford, Ontario

    Energy Technology Data Exchange (ETDEWEB)

    Hensel, M.J.; Thompson, J. [The Walter Fedy Partnership, Kitchener, ON (Canada)

    1998-12-31

    The four-acre ecological restoration of tall grass prairie, wetland and Savannah ecosystems within the Union Gas Customer Service Centre in Brantford, Ontario is discussed. The restoration of the Brant Prairie site was instigated three years ago through Union Gas` land stewardship and environmental action initiative which tried to encourage the diversity and dynamics of each ecosystem, while creating a community resource for visitors to learn about natural heritage. The Brantford initiative includes: (1) protecting the sedge wetland which contained regionally rare species, (2) maintaining the dynamic water budget while protecting the sedge wetland from roadway contaminants, (3) creating a tall grass prairie similar in diversity and aesthetics to Brantford`s surviving prairie remnants, (4) creating a wildlife habitat for butterflies, birds and aquatic species, and (5) rediscovering partridge pea by uncovering a historic seed bank.

  3. Proceedings of the third prairie conservation and endangered species workshop

    Energy Technology Data Exchange (ETDEWEB)

    Holroyd, G.L.; Diskson, H.L.; Regnier, M.; Smith, H.C. (eds.)

    1993-01-01

    The Canadian prairies support a major agricultural economy and a declining abundance of wildlife. Soil erosion and water quality threaten the long-term viability of agriculture; half of Canada's endangered and threatened birds and mammals share the prairies. Wise policies of resource management are needed to solve these problems. A workshop was held to address the issue of how to manage the prairies to promote sustained agriculture and to conserve the wildlife that are in jeopardy. Papers were presented on the relationships between agriculture and wildlife, land restoration, climate change, pesticides, the Prairie Conservation Action Plan, plant conservation, amphibians, reptiles, migratory birds and other wildfowl, and mammals. Separate abstracts have been prepared for two papers from this workshop.

  4. Reduced fine-scale spatial genetic structure in grazed populations of Dianthus carthusianorum.

    Science.gov (United States)

    Rico, Y; Wagner, H H

    2016-11-01

    Strong spatial genetic structure in plant populations can increase homozygosity, reducing genetic diversity and adaptive potential. The strength of spatial genetic structure largely depends on rates of seed dispersal and pollen flow. Seeds without dispersal adaptations are likely to be dispersed over short distances within the vicinity of the mother plant, resulting in spatial clustering of related genotypes (fine-scale spatial genetic structure, hereafter spatial genetic structure (SGS)). However, primary seed dispersal by zoochory can promote effective dispersal, increasing the mixing of seeds and influencing SGS within plant populations. In this study, we investigated the effects of seed dispersal by rotational sheep grazing on the strength of SGS and genetic diversity using 11 nuclear microsatellites for 49 populations of the calcareous grassland forb Dianthus carthusianorum. Populations connected by rotational sheep grazing showed significantly weaker SGS and higher genetic diversity than populations in ungrazed grasslands. Independent of grazing treatment, small populations showed significantly stronger SGS and lower genetic diversity than larger populations, likely due to genetic drift. A lack of significant differences in the strength of SGS and genetic diversity between populations that were recently colonized and pre-existing populations suggested that populations colonized after the reintroduction of rotational sheep grazing were likely founded by colonists from diverse source populations. We conclude that dispersal by rotational sheep grazing has the potential to considerably reduce SGS within D. carthusianorum populations. Our study highlights the effectiveness of landscape management by rotational sheep grazing to importantly reduce genetic structure at local scales within restored plant populations.

  5. Ingestive behavior of supplemented Nellore heifers grazing palisadegrass pastures managed with different sward heights.

    Science.gov (United States)

    Vieira, Bruno Ramalho; Azenha, Mariana Vieira; Casagrande, Daniel Rume; Costa, Diogo Fleury Azevedo; Ruggieri, Ana Cláudia; Berchielli, Telma Teresinha; Reis, Ricardo Andrade

    2017-04-01

    Three sward heights (15, 25 and 35 cm) and three supplement types (energy, energy-protein, and a mineral mix supplement) were evaluated in a 3 × 3 factorial arrangement distributed in a completely randomized design to study changes in forage search patterns in Nellore heifers in a continuous grazing system. Pasture data were collected using two replicates (paddocks) per treatment over four periods during the rainy season. The behavior assessments were made in the first and fourth grazing seasons. It was hypothesized that supplements and pasture management would modify ingestive behavior, considering that animals would require less time grazing if they had energy requirements met through higher digestibility of better managed paddocks, or use of supplements high in energy. Total and green forage masses along with green : dead material ratio were greater in treatments managed with higher sward heights. Sward managed with 35 cm height resulted in lower leaf : stem ratio compared with 15 cm sward height treatments. The animals on the 15 cm pastures spent more time grazing overall and during each meal, but there were no differences observed in meal numbers in comparison to 35 cm treatments. Heifers fed protein and/or energy supplements spent less time grazing in the early afternoon, but overall grazing time was the same for all animals. © 2016 Japanese Society of Animal Science.

  6. Environmental Impacts of Wind Power Development on the Population Biology of Greater Prairie-Chickens

    Energy Technology Data Exchange (ETDEWEB)

    Sandercock, Brett K. [Kansas State University

    2013-05-22

    abandoned lek sites were located <5 km from turbines. Probability of lek persistence was significantly related to habitat and number of males. Leks had a higher probability of persistence in grasslands than agricultural fields, and increased from ~0.2 for leks of 5 males, to >0.9 for leks of 10 or more males. Large leks in grasslands should be a higher priority for conservation. Overall, wind power development had a weak effect on the annual probability of lek persistence. 3. We used molecular methods to investigate the mating behavior of prairie chickens. The prevailing view for lek-mating grouse is that females mate once to fertilize the clutch and that conspecific nest parasitism is rare. We found evidence that females mate multiple times to fertilize the clutch (8-18% of broods, 4-38% of chicks) and will parasitize nests of other females during egg-laying (~17% of nests). Variable rates of parentage were highest in the fragmented landscapes at the Smoky Hills field site, and were lower at the Flint Hills field site. Comparisons of the pre- and postconstruction periods showed that wind energy development did not affect the mating behaviors of prairie chickens. 4. We examined use of breeding habitats by radio-marked females and conducted separate analyses for nest site selection, and movements of females not attending nests or broods. The landscape was a mix of native prairie and agricultural habitats, and nest site selection was not random because females preferred to nest in grasslands. Nests tended to be closer to turbines during the postconstruction period and there was no evidence of behavioral avoidance of turbines by females during nest site selection. Movements of females not attending nests or broods showed that females crossed the site of the wind power development at higher rates during the preconstruction period (20%) than the postconstruction period (11%), and that movements away from turbines were more frequent during the postconstruction period. Thus, wind

  7. Disease limits populations: plague and black-tailed prairie dogs

    Science.gov (United States)

    Cully, Jack F.; Johnson, T.; Collinge, S.K.; Ray, C.

    2010-01-01

    Plague is an exotic vector-borne disease caused by the bacterium Yersinia pestis that causes mortality rates approaching 100% in black-tailed prairie dogs (Cynomys ludovicianus). We mapped the perimeter of the active portions of black-tailed prairie dog colonies annually between 1999 and 2005 at four prairie dog colony complexes in areas with a history of plague, as well as at two complexes that were located outside the distribution of plague at the time of mapping and had therefore never been affected by the disease. We hypothesized that the presence of plague would significantly reduce overall black-tailed prairie dog colony area, reduce the sizes of colonies on these landscapes, and increase nearest-neighbor distances between colonies. Within the region historically affected by plague, individual colonies were smaller, nearest-neighbor distances were greater, and the proportion of potential habitat occupied by active prairie dog colonies was smaller than at plague-free sites. Populations that endured plague were composed of fewer large colonies (>100 ha) than populations that were historically plague free. We suggest that these differences among sites in colony size and isolation may slow recolonization after extirpation. At the same time, greater intercolony distances may also reduce intercolony transmission of pathogens. Reduced transmission among smaller and more distant colonies may ultimately enhance long-term prairie dog population persistence in areas where plague is present.

  8. Interspecific comparisons of sylvatic plague in prairie dogs

    Science.gov (United States)

    Cully, J.F.; Williams, E.S.

    2001-01-01

    Of the 3 major factors (habitat loss, poisoning, and disease) that limit abundance of prairie dogs today, sylvatic plague caused by Yersinia pestis is the 1 factor that is beyond human control. Plague epizootics frequently kill >99% of prairie dogs in infected colonies. Although epizootics of sylvatic plague occur throughout most of the range of prairie dogs in the United States and are well described, long-term maintenance of plague in enzootic rodent species is not well documented or understood. We review dynamics of plague in white-tailed (Cynomys leucurus), Gunnison's (C. gunnisoni), and black-tailed (C. ludovicianus) prairie dogs, and their rodent and flea associates. We use epidemiologic concepts to support an enzootic hypothesis in which the disease is maintained in a dynamic state, which requires transmission of Y. pestis to be slower than recruitment of new susceptible mammal hosts. Major effects of plague are to reduce colony size of black-tailed prairie dogs and increase intercolony distances within colony complexes. In the presence of plague, black-tailed prairie dogs will probably survive in complexes of small colonies that are usually >3 km from their nearest neighbor colonies.

  9. Effects of chicory/perennial ryegrass swards compared with perennial ryegrass swards on the performance and carcass quality of grazing beef steers.

    Directory of Open Access Journals (Sweden)

    Christina L Marley

    Full Text Available An experiment investigated whether the inclusion of chicory (Cichorium intybus in swards grazed by beef steers altered their performance, carcass characteristics or parasitism when compared to steers grazing perennial ryegrass (Lolium perenne. Triplicate 2-ha plots were established with a chicory/ryegrass mix or ryegrass control. Forty-eight Belgian Blue-cross steers were used in the first grazing season and a core group (n = 36 were retained for finishing in the second grazing season. The experiment comprised of a standardisation and measurement period. During standardisation, steers grazed a ryegrass/white clover pasture as one group. Animals were allocated to treatment on the basis of liveweight, body condition and faecal egg counts (FEC determined 7 days prior to the measurement period. The measurement period ran from 25 May until 28 September 2010 and 12 April until 11 October 2011 in the first and second grazing year. Steers were weighed every 14 days at pasture or 28 days during housing. In the first grazing year, faecal samples were collected for FEC and parasite cultures. At the end of the first grazing year, individual blood samples were taken to determine O. ostertagi antibody and plasma pepsinogen levels. During winter, animals were housed as one group and fed silage. In the second grazing year, steers were slaughtered when deemed to reach fat class 3. Data on steer performance showed no differences in daily live-weight gain which averaged 1.04 kg/day. The conformation, fat grade and killing out proportion of beef steers grazing chicory/ryegrass or ryegrass were not found to differ. No differences in FEC, O. ostertagi antibody or plasma pepsinogen levels of beef steers grazing either chicory/ryegrass or ryegrass were observed. Overall, there were no detrimental effects of including chicory in swards grazed by beef cattle on their performance, carcass characteristics or helminth parasitism, when compared with steers grazing ryegrass.

  10. Montana Valley and Foothill Prairies Ecoregion: Chapter 6 in Status and trends of land change in the Western United States--1973 to 2000

    Science.gov (United States)

    Taylor, Janis L.

    2012-01-01

    The Montana Valley and Foothill Prairies Ecoregion comprises numerous intermountain valleys and low-elevation foothill prairies spread across the western half of Montana, on both sides of the Continental Divide (Omernik, 1987; U.S. Environmental Protection Agency, 1997). The ecoregion, which covers approximately 64,658 km2 (24,965 mi2), includes the Flathead Valley and the valleys surrounding Helena, Missoula, Bozeman, Billings, Anaconda, Dillon, and Lewistown (fig. 1). These valleys are generally characterized by shortgrass prairie vegetation and are flanked by forested mountains (Woods and others, 1999); thus, the valleys’ biotas with regards to fish and insects are comparable. In many cases, the valleys are conduits for some of the largest rivers in the state, including Clark Fork and the Missouri, Jefferson, Madison, Flathead, Yellowstone, Gallatin, Smith, Big Hole, Bitterroot, and Blackfoot Rivers (fig. 2). The Montana Valley and Foothill Prairies Ecoregion also includes the “Rocky Mountain front,” an area of prairies along the eastern slope of the northern Rocky Mountains. Principal land uses within the ecoregion include farming, grazing, and mining. The valleys serve as major transportation and utility corridors and also contain the majority of Montana’s human population. The Montana Valley and Foothill Prairies Ecoregion extends into 17 mostly rural counties throughout western Montana. Only three of the counties—Carbon, Yellowstone, and Missoula—are part of a metropolitan statistical area with contiguous built-up areas tied to an employment center. Nearly two-thirds of Montana residents live in nonmetropolitan counties (Albrecht, 2008). Ten of the counties within the ecoregion had population growth rates greater than national averages (9–13 percent) between 1970 and 2000 (table 1). Ravalli and Gallatin Counties had the highest growth rates. Population growth was largely due to amenity-related inmigration and an economy dependent on tourism

  11. Greenhouse Gas Emission from Beef Cattle Grazing Systems on Temperate Grasslands

    Science.gov (United States)

    Rice, C. W.; Rivera-Zayas, J.

    2017-12-01

    At a global scale, cattle production is responsible for 65% of GHG emissions. During 2014 cattle management was the largest emitters of methane (CH4) representing a 23.2% of the total CH4 from anthropogenic activities. Since 2014, gas samples have been gathered and analyzed for carbon dioxide (CO2), CH4 and nitrous oxide (N2O) from three grazing areas under three different burning regimes at the temperate grassland of Konza Prairie Biological Station in Kansas. Burning regimes included one site in annually burned, and two sites with patch burned every three years on offset years. Burning regimes showed no effect in N2O emissions (pconsumed on grazed grassland soils; with an increase in consumption with patch burning. Results quantify the role of temperate grasslands as a sink of CH4, and a possible sink of N2O. This experiment evidence CO2, CH4 and N2O emissions behavior as a consequence of burning regimes, and quantify the role of temperate grasslands as a sink of CH4 and N2O in order to understand best practice for resilience of beef cattle management.

  12. Investigation of the Transcriptome of Prairie Cord Grass, a New Cellulosic Biomass Crop

    KAUST Repository

    Gedye, Kristene; Gonzalez-Hernandez, Jose; Ban, Yuguang; Ge, Xijin; Thimmapuram, Jyothi; Sun, Fengjie; Wright, Chris; Ali, Shahjahan; Boe, Arvid; Owens, Vance

    2010-01-01

    in this paper describes the first investigation of the transcriptome of prairie cordgrass via Next Generation Sequencing Technology, 454 GS FLX. A total of 556,198 expressed sequence tags (ESTs) were produced from four prairie cordgrass tissues: roots, rhizomes

  13. 36 CFR 293.7 - Grazing of livestock.

    Science.gov (United States)

    2010-07-01

    ... 36 Parks, Forests, and Public Property 2 2010-07-01 2010-07-01 false Grazing of livestock. 293.7...-PRIMITIVE AREAS § 293.7 Grazing of livestock. (a) The grazing of livestock, where such use was established..., shall be permitted to continue under the general regulations covering grazing of livestock on the...

  14. Productivity of grasslands under continuous and rotational grazing

    NARCIS (Netherlands)

    Lantinga, E.A.

    1985-01-01

    In the Netherlands, rotational grazing, with grazing periods of 2 to 5 days, is the most common grazing system at present. In contrast with other countries of North-western Europe, the continuous grazing system is used here only to a limited extent. However, the results of numerous

  15. Prairie revegetation of a strip mine in Illinois: fifteen years after establishment

    Energy Technology Data Exchange (ETDEWEB)

    Corbett, E.A.; Anderson, R.C.; Rodgers, C.S. [Illinois State University, Normal, IL (United States). Dept. of Biological Sciences

    1996-12-01

    The long-term success of prairie planting on a former strip mine in northeastern Illinois was investigated. The site was reclaimed and planted with prairie species in the 1970s. Total biomass increased over time, largely as a result of an increase in biomass of non-prairie species. Biomass of prairie species remained unchanged because of an increase in Panicum virgatum (switchgrass) offsetting decreases in Sorghastrum nutans (Indian grass).

  16. Grazing management that regenerates ecosystem function and ...

    African Journals Online (AJOL)

    Grazing management that regenerates ecosystem function and grazingland ... in ecosystem improvement, productivity, soil carbon and fertility, water-holding ... for sufficient time to produce resource improvement, sound animal production, and ...

  17. Small mammals in successional prairie woodlands of the northern Great Plains

    Science.gov (United States)

    Mark A. Rumble; John E. Gobeille

    2001-01-01

    Prairie woodlands comprise about 1 percent of the landscape in the northern Great Plains. However, prairie woodlands provide habitat for far more than 1 percent of the wildlife species that occur in the prairie region. With increasing pressures on natural resources, managers need methods for managing wildlife habitat and biodiversity that are based on ecological...

  18. 76 FR 77245 - Attwater Prairie Chicken National Wildlife Refuge, Austin and Colorado Counties, TX...

    Science.gov (United States)

    2011-12-12

    ...-FF02R06000] Attwater Prairie Chicken National Wildlife Refuge, Austin and Colorado Counties, TX... (EA) for Attwater Prairie Chicken National Wildlife Refuge (Refuge, NWR), located approximately 60... Prairie Chicken NWR draft CCP and EA'' in the subject line of the message. Fax: Attn: Monica Kimbrough...

  19. 75 FR 21649 - Endangered and Threatened Wildlife and Plants; Attwater's Prairie-Chicken (Tympanuchus cupido...

    Science.gov (United States)

    2010-04-26

    ...] Endangered and Threatened Wildlife and Plants; Attwater's Prairie-Chicken (Tympanuchus cupido attwateri... availability of the Attwater's Prairie-Chicken (Tympanuchus cupido attwateri) Recovery Plan, Second Revision. A recovery plan was originally completed for the Attwater's prairie-chicken in 1983 and revised in 1993...

  20. Grazing function g and collimation angular acceptance

    Directory of Open Access Journals (Sweden)

    Stephen G. Peggs

    2009-11-01

    Full Text Available The grazing function g is introduced—a synchrobetatron optical quantity that is analogous (and closely connected to the Twiss and dispersion functions β, α, η, and η^{′}. It parametrizes the rate of change of total angle with respect to synchrotron amplitude for grazing particles, which just touch the surface of an aperture when their synchrotron and betatron oscillations are simultaneously (in time at their extreme displacements. The grazing function can be important at collimators with limited acceptance angles. For example, it is important in both modes of crystal collimation operation—in channeling and in volume reflection. The grazing function is independent of the collimator type—crystal or amorphous—but can depend strongly on its azimuthal location. The rigorous synchrobetatron condition g=0 is solved, by invoking the close connection between the grazing function and the slope of the normalized dispersion. Propagation of the grazing function is described, through drifts, dipoles, and quadrupoles. Analytic expressions are developed for g in perfectly matched periodic FODO cells, and in the presence of β or η error waves. These analytic approximations are shown to be, in general, in good agreement with realistic numerical examples. The grazing function is shown to scale linearly with FODO cell bend angle, but to be independent of FODO cell length. The ideal value is g=0 at the collimator, but finite nonzero values are acceptable. Practically achievable grazing functions are described and evaluated, for both amorphous and crystal primary collimators, at RHIC, the SPS (UA9, the Tevatron (T-980, and the LHC.

  1. Vulnerability of shortgrass prairie bird assemblages to climate change

    Science.gov (United States)

    Skagen, Susan K.; Dreitz, Victoria; Conrey, Reesa Y.; Yackel, Amy; Panjabi, Arvind O.; Knuffman, Lekha

    2016-01-01

    The habitats and resources needed to support grassland birds endemic to North American prairie ecosystems are seriously threatened by impending climate change. To assess the vulnerability of grassland birds to climate change, we consider various components of vulnerability, including sensitivity, exposure, and adaptive capacity (Glick et al. 2011). Sensitivity encompasses the innate characteristics of a species and, in this context, is related to a species’ tolerance to changes in weather patterns. Groundnesting birds, including prairie birds, are particularly responsive to heat waves combined with drought conditions, as revealed by abundance and distribution patterns (Albright et al. 2010). To further assess sensitivity, we estimated reproductive parameters of nearly 3000 breeding attempts of a suite of prairie birds relative to prevailing weather. Fluctuations in weather conditions in eastern Colorado, 1997-2014, influenced breeding performance of a suite of avian species endemic to the shortgrass prairie, many of which have experienced recent population declines. High summer temperatures and intense rain events corresponded with lower nest survival for most species. Although dry conditions favored nest survival of Burrowing Owls and Mountain Plovers (Conrey 2010, Dreitz et al. 2012), drought resulted in smaller clutch sizes and lower nest survival for passerines (Skagen and Yackel Adams 2012, Conrey et al. in review). Declining summer precipitation may reduce the likelihood that some passerine species can maintain stable breeding populations in this region of the shortgrass prairie.

  2. Prairie dogs increase fitness by killing interspecific competitors.

    Science.gov (United States)

    Hoogland, John L; Brown, Charles R

    2016-03-30

    Interspecific competition commonly selects for divergence in ecology, morphology or physiology, but direct observation of interspecific competition under natural conditions is difficult. Herbivorous white-tailed prairie dogs (Cynomys leucurus) employ an unusual strategy to reduce interspecific competition: they kill, but do not consume, herbivorous Wyoming ground squirrels (Urocitellus elegans) encountered in the prairie dog territories. Results from a 6-year study in Colorado, USA, revealed that interspecific killing of ground squirrels by prairie dogs was common, involving 47 different killers; 19 prairie dogs were serial killers in the same or consecutive years, and 30% of female prairie dogs killed at least one ground squirrel over their lifetimes. Females that killed ground squirrels had significantly higher annual and lifetime fitness than non-killers, probably because of decreased interspecific competition for vegetation. Our results document the first case of interspecific killing of competing individuals unrelated to predation (IK) among herbivorous mammals in the wild, and show that IK enhances fitness for animals living under natural conditions. © 2016 The Author(s).

  3. Performance of Angus and Brangus cow-calf pairs grazing Alicia bermudagrass and common bermudagrass-dallisgrass pastures.

    Science.gov (United States)

    Wyatt, W E; Gates, R N; Blouin, D C; Saxton, A M; Nelson, B D

    1997-07-01

    This research was designed to examine genotype x environment interactions in cow-calf growth performance of grazing animals. Angus and Brangus cow-calf pairs (minimum of six per breed) were allowed to rotationally graze (14-d intervals) treatment pastures from approximately May through early October in each of 2 yr. Treatment pastures contained relatively pure stands of Alicia bermudagrass (AP) or a mixed stand of common bermudagrass and dallisgrass (CDP). Forage allowance was equalized, using "put-and-take" cow-calf pairs, among forage and breed types at the initiation of each 14-d grazing interval. Forage samples were obtained in each paddock at the initiation of each grazing interval. Forage CP concentration was greater (P < .05; 13.5 vs 11.6%) and NDF concentration was less (P < .05; 63.8 vs 70.6%) for CDP than for AP. Daily weight loss was similar for Angus and Brangus cows, but it was greater (P < .05) for cows grazing AP than for cows grazing CDP. Calf ADG during the grazing season was 35% greater (P < .05) for CDP than for AP pastures and was 23% greater (P < .01) for Brangus than for Angus calves. Relative performance of Angus and Brangus cow-calf pairs was consistent between forages; no breed x forage interactions were observed.

  4. Grazing behavior and intake of goats rotationally grazing Tanzania-grass pasture with different post-grazing residues

    Directory of Open Access Journals (Sweden)

    Marcia H.M.R. Fernandes

    2016-05-01

    Full Text Available This study aimed to evaluate intake and ingestive behavior of goats rotationally grazing Tanzania (Panicum maximum cv. Tanzânia 1 pastures with 2 levels of post-grazing residue. The experimental area consisted of 1.2 ha of Tanzania pasture divided into 12 paddocks (24 areas, managed under 2 post-grazing residues: low green (leaf + stem herbage mass (GHM post-grazing (LR, approximately 1,500 kg/ha GHM; and high GHM post-grazing (HR, approximately 3,000 kg/ha GHM. Each paddock was grazed for 3 consecutive days (D1, D2, D3 followed by 33 days rest and evaluated from October 2005 to April 2006. Animal behavior (grazing time, bite rate and bite size/weight was evaluated on each grazing day. While goats spent more time grazing on LR than HR (P=0.02, bite rate did not differ between treatments or among days (P=0.31 and averaged 26.5 bites/min. In contrast, bite weight was greater in HR (0.15 g/bite than in LR (0.12 g/bite, and decreased from D1 to D3 (P<0.001. Absolute dry matter intake of goats was greater in the HR (2.19 kg/d than the LR (1.89 kg/d treatment; however, differences were not significant (P>0.05 when intake was determined on a body weight or metabolic weight basis. Our findings are consistent with the general assumption that bite weight is a trade-off between quantity and quality of the herbage mass and is the main determinant of animal performance. More studies are needed to determine animal performance on the various treatments and to determine management strategies to provide a desirable balance between animal weight gain and pasture stability.Keywords: Animal behavior, foraging, grazing systems, Megathyrsus maximus, plant - animal relations.DOI: 10.17138/TGFT(491-100

  5. The response of spider (Araneae assemblages to structural heterogeneity and prey abundance in sub-montane vegetation modified by conservation grazing

    Directory of Open Access Journals (Sweden)

    Peter Dennis

    2015-01-01

    Full Text Available The effect of experimental livestock grazing regimens (4 treatments×6 replicates on spiders via habitat structure and prey abundance was investigated on sub-montane habitats in the Southern Highlands of Scotland. The study, 2002–2004 included a baseline survey under the prior, commercial sheep grazing regimen and two assessments of spider assemblages post-treatment: commercial stocking density of sheep; 1/3 stocking density with sheep; 1/3 stocking density cattle with sheep; and no grazing. Spiders were sampled with a suction sampler, five sucks at each of 25 sample units by 24 plots (600 samples in 2003 and 2004, ca. 320 in 2002. Spider abundance and species richness increased under reduced stocking density, mixed herbivore and ungrazed treatments indirectly via changes in vegetation structure and prey abundance. The results refuted a meta-analysis that concluded species richness of spiders is unaffected by grazing. Grazing regimens caused turnover in species composition more than the net difference in species richness suggested, implying that no single, optimal grazing regimen will support as many species as a patchwork under varied grazing management. Conservation grazing benefits spiders and will have significant benefits for food webs in sub-montane ecosystems but the period to equilibrium after changes to grazing requires further investigation.

  6. Mineral supplementation for grazing ruminants

    International Nuclear Information System (INIS)

    McDowell, L.R.; Conrad, J.H.; Ellis, G.L.

    1986-01-01

    Grazing ruminants to which concentrate feeds cannot be economically fed must rely on self-feeding of mineral supplements. A number of factors affect mineral consumption of free-choice mixtures. Livestock exhibit little nutritional wisdom and will select palatable mixtures in preference to mixtures designed to meet their requirements. Palatability and appetite stimulators are often used to achieve a more uniform herd-wide consumption. It is best to formulate free-choice mixtures on the basis of analyses or other available data. However, when no information on mineral status is known, a free-choice complete mineral supplement is warranted. A 'complete' mineral mixture usually includes salt, a low fluoride P source, Ca, Co, Cu, I, Mn and Zn. Selenium, Mg, K, S, Fe or additional elements can be incorporated into a mineral supplement as new information suggests a need. The detriment to ruminant production caused by providing Ca, Se and Cu in excess can be greater than any benefit derived by providing a mineral supplement. In regions where high forage Mo predominates, three to five times the Cu content in mineral mixtures is needed to counteract Mo toxicity. Supplemental minerals are most critical during the wet season, when cattle are gaining weight rapidly and energy and protein supplies are adequate. Economic return on mineral supplementation is high. (author)

  7. Effect of day or night grazing on behaviour of swamp buffalo heifers

    Directory of Open Access Journals (Sweden)

    Somparn, P.

    2007-03-01

    Full Text Available An experiment was conducted to examine the effect of day or night grazing on behaviour by swamp buffaloes. A grazing trial was conducted over 42 days in the late rainy season, during September to November2005 at Surin Livestock Research and Breeding Center, Surin province. The experimental period was divided into two 21-day periods. Twelve 2-year-old swamp buffalo heifers were allocated to four groups, eachcontaining three heifers, with the mean group weights being as similar as possible. Each group was allowed to graze either from 06:20 to 18:00 h (daytime treatment or from 18:20 to 06:00 h (nighttime treatment infour separate paddocks, each of 5 rai, using a cross-over design. When not at pasture the animals in each group were kept in the common corral with free access to fresh drinking water and mineral blocks. Individualanimal activity was recorded by visual observation at 1-min intervals during the period at pasture. Individual groups within each period were treated as replicates. Differences between group means weretested using MIXED procedure of SAS.The buffaloes on daytime treatment spent longer (P<0.05 grazing than those on nighttime treatment (423 vs 332 min. The number of meals differed (P<0.05 between treatments, but overall mean meal durationswere similar (73 min. Buffaloes allowed to graze during daylight had a tendency (P<0.10 toward a higher bite and step rates than those grazing during the night. With the reduction in grazing activity duringthe night on nighttime treatment, the animals ruminated for longer during the period at pasture (327 and 191 min, P<0.001. Live-weight change over periods of 20 days did not differ significantly. The difference intemporal behaviour patterns between treatments indicated that animals have to adapt foraging strategies appropriate for different situations in order to maintain feed intake and subsequently production.

  8. Spent fuel storage at Prairie Island: January 1995 status

    International Nuclear Information System (INIS)

    Closs, J.; Kress, L.

    1995-01-01

    The disposal of spent nuclear fuel has been an issue for the US since the inception of the commercial nuclear power industry. In the past decade, it has become a critical factor in the continued operation of some nuclear power plants, including the two units at Prairie Island. As the struggles and litigation over storage alternatives wage on, spent fuel pools continue to fill and plants edge closer to premature shutdown. Due to the delays in the construction of a federal repository, many nuclear power plants have had to seek interim storage alternatives. In the case of Prairie Island, the safest and most feasible option is dry cask storage. This paper discusses the current status of the Independent Spent Fuel Storage Installation (ISFSI) Project at Prairie Island. It provides a historical background to the project, discusses the notable developments over the past year, and presents the projected plans of the Northern States Power Company (NSP) in regards to spent fuel storage

  9. Morphological Responses Explain Tolerance of the Bamboo Yushania microphylla to Grazing

    Directory of Open Access Journals (Sweden)

    Kesang Wangchuk

    2014-01-01

    Full Text Available Mechanisms of tolerance of the bamboo Y. microphylla to ungulate herbivory were investigated by measuring above- and belowground morphogenetic traits and biomass allocation patterns of the bamboo Y. microphylla under grazed and ungrazed conditions in a Himalayan mixed conifer forest. Data were collected from 5 populations consisting of 10 ramets each in adjacent grazed and ungrazed plots. Compared with ungrazed ramets, the aboveground morphological modifications of grazed ramets were higher culm density, shorter and thinner culms, shorter internode, and shorter top leaf. The belowground morphological modifications for the grazed ramets were thinner rhizomes, lower rhizome biomass and dry matter, more nodes, and shorter internodes. Despite the lower biomass and dry matter, the root-to-shoot ratio was higher for grazed ramets. Results suggest that Y. microphylla subjected to herbivory shows aboveground overcompensation in terms of densification at the cost of belowground biomass, but at the same time maintains a higher proportion of belowground reserves, as compared to ungrazed conditions. These responses provide adequate evidence to conclude that Y. microphylla tolerates ungulate herbivory through above- and belowground morphological modifications.

  10. Global warming and prairie wetlands: potential consequences for waterfowl habitat

    Science.gov (United States)

    Poiani, Karen A.; Johnson, W. Carter

    1991-01-01

    The accumulation of greenhouse gasses in the atmosphere is expected to warm the earth's climate at an unprecedented rate (Ramanathan 1988, Schneider 1989). If the climate models are correct, within 100 years the earth will not only be warmer than it has been during the past million years, but the change will have occurred more rapidly than any on record. Many profound changes in the earth's environment are expected, including rising sea level, increasing aridity in continental interiors, and melting permafrost. Ecosystems are expected to respond variously to a rapidly changing climate. Tree ranges in eastern North American are expected to shift northward, and seed dispersal may not be adequate to maintain current diversity (Cohn 1989, Johnson and Webb 1989). In coastal wetlands, rising sea level from melting icecaps and thermal expansion could flood salt-grass marshes and generally reduce the size and productivity of the intertidal zone (Peters and Darling 1985). As yet, little attention has been given to the possible effects of climatic warming on inland prairie wetland ecosystems. These wetlands, located in the glaciated portion of the North American Great Plains (Figure 1), constitute the single most important breeding area for waterfowl on this continent (Hubbard 1988). This region annually produces 50-80% of the continent's total duck production (Batt et al. 1989). These marshes also support a variety of other wildlife, including many species of nongame birds, muskrat, and mink (Kantrud et al. 1989a). Prairie wetlands are relatively shallow, water-holding depressions that vary in size, water permanence, and water chemistry. Permanence types include temporary ponds (typically holding water for a few weeks in the springs), seasonal ponds (holding water from spring until early summer), semipermanent ponds (holding water throughout the growing season during most years), and large permanent lakes (Stewart and Kantrud 1971). Refilling usually occurs in spring from

  11. The grazing capacity of sweetveld: 2. A model to estimate grazing ...

    African Journals Online (AJOL)

    The relations between grazing capacity and three independent variables were investigated in the False Thornveld of the Eastern Cape. The variables were veld condition, rainfall and density of woody species. These relations were used to develop a preliminary model to assess grazing capacity in the veld type. Despite its ...

  12. Paltry past-precipitation: Predisposing prairie dogs to plague?

    Science.gov (United States)

    Eads, David; Biggins, Dean E.

    2017-01-01

    The plague bacterium Yersinia pestis was introduced to California in 1900 and spread rapidly as a sylvatic disease of mammalian hosts and flea vectors, invading the Great Plains in the United States by the 1930s to 1940s. In grassland ecosystems, plague causes periodic, devastating epizootics in colonies of black-tailed prairie dogs (Cynomys ludovicianus), sciurid rodents that create and maintain subterranean burrows. In doing so, plague inhibits prairie dogs from functioning as keystone species of grassland communities. The rate at which fleas transmit Y. pestis is thought to increase when fleas are abundant. Flea densities can increase during droughts when vegetative production is reduced and herbivorous prairie dogs are malnourished and have weakened defenses against fleas. Epizootics of plague have erupted frequently in prairie dogs during years in which precipitation was plentiful, and the accompanying cool temperatures might have facilitated the rate at which fleas transmitted Y. pestis. Together these observations evoke the hypothesis that transitions from dry-to-wet years provide conditions for plague epizootics in prairie dogs. Using generalized linear models, we analyzed a 24-year dataset on the occurrence of plague epizootics in 42 colonies of prairie dogs from Colorado, USA, 1982–2005. Of the 33 epizootics observed, 52% erupted during years with increased precipitation in summer. For the years with increased summer precipitation, if precipitation in the prior growing season declined from the maximum of 502 mm to the minimum of 200 mm, the prevalence of plague epizootics was predicted to increase 3-fold. Thus, reduced precipitation may have predisposed prairie dogs to plague epizootics when moisture returned. Biologists sometimes assume dry conditions are detrimental for plague. However, 48% of epizootics occurred during years in which precipitation was scarce in summer. In some cases, an increased abundance of fleas during dry years might

  13. Urban Rights-of-Way as Reservoirs for Tall-Grass Prairie Plants and Butterflies

    Science.gov (United States)

    Leston, Lionel; Koper, Nicola

    2016-03-01

    Urban rights-of-way may be potential reservoirs of tall-grass prairie plants and butterflies. To determine if this is true, in 2007-2008, we conducted vegetation surveys of species richness and cover, and butterfly surveys of species richness and abundance, along 52 transmission lines and four remnant prairies in Winnipeg, Manitoba. We detected many prairie plants and butterflies within transmission lines. Some unmowed and infrequently managed transmission lines had native plant species richness and total percent cover of native plants comparable to that of similar-sized remnant tall-grass prairies in the region. Although we did not find significant differences in overall native butterfly numbers or species richness between rights-of-way and remnant prairies, we found lower numbers of some prairie butterflies along frequently mowed rights-of-way than within remnant tall-grass prairies. We also observed higher butterfly species richness along sites with more native plant species. By reducing mowing and spraying and reintroducing tall-grass prairie plants, urban rights-of-way could serve as extensive reservoirs for tall-grass prairie plants and butterflies in urban landscapes. Eventually, managing urban rights-of-way as reservoirs for tall-grass prairie plants and animals could contribute to the restoration of tall-grass prairie in the North American Midwest.

  14. Urban Rights-of-Way as Reservoirs for Tall-Grass Prairie Plants and Butterflies.

    Science.gov (United States)

    Leston, Lionel; Koper, Nicola

    2016-03-01

    Urban rights-of-way may be potential reservoirs of tall-grass prairie plants and butterflies. To determine if this is true, in 2007-2008, we conducted vegetation surveys of species richness and cover, and butterfly surveys of species richness and abundance, along 52 transmission lines and four remnant prairies in Winnipeg, Manitoba. We detected many prairie plants and butterflies within transmission lines. Some unmowed and infrequently managed transmission lines had native plant species richness and total percent cover of native plants comparable to that of similar-sized remnant tall-grass prairies in the region. Although we did not find significant differences in overall native butterfly numbers or species richness between rights-of-way and remnant prairies, we found lower numbers of some prairie butterflies along frequently mowed rights-of-way than within remnant tall-grass prairies. We also observed higher butterfly species richness along sites with more native plant species. By reducing mowing and spraying and reintroducing tall-grass prairie plants, urban rights-of-way could serve as extensive reservoirs for tall-grass prairie plants and butterflies in urban landscapes. Eventually, managing urban rights-of-way as reservoirs for tall-grass prairie plants and animals could contribute to the restoration of tall-grass prairie in the North American Midwest.

  15. Fecal microbiota of lambs fed purple prairie clover (Dalea purpurea Vent.) and alfalfa (Medicago sativa).

    Science.gov (United States)

    Huang, Qianqian; Holman, Devin B; Alexander, Trevor; Hu, Tianming; Jin, Long; Xu, Zhongjun; McAllister, Tim A; Acharya, Surya; Zhao, Guoqi; Wang, Yuxi

    2018-01-01

    The present study assessed the effect of purple prairie clover (PPC) and PPC condensed tannins (CT) on the fecal microbiota of lambs using high-throughput 16S rRNA gene pyrosequencing. A total of 18 individual lambs were randomly divided into three groups and fed either green chop alfalfa (Alf), a 40:60 (DM basis; Mix) mixture of Alf and PPC, or Mix supplemented with polyethylene glycol (Mix-P) for 18 days. Fecal samples were collected on days 13 through 18 using digital rectal retrieval. The DNA of fecal samples was extracted and the microbial 16S rRNA gene amplicons were sequenced using 454 pyrosequencing. Regardless of diet, the bacterial community was dominated by Firmicutes and Bacteroidetes with many sequences unclassified at the genus level. Forage type and CT had no effect on the fecal microbial composition at the phylum level or on α-diversity. Compared to the Alf diet, the Mix diet reduced the relative abundance of Akkermansia (P = 0.03) and Asteroleplasma (P = 0.05). Fecal microbial populations in Alf and Mix-P clustered separately from each other when assessed using unweighted UniFrac (P < 0.05). These results indicate that PPC CT up to 36 g/kg DM in the diet had no major effect on fecal microbial flora at the phyla level and exerted only minor effects on the genera composition of fecal microbiota in lambs.

  16. Effect of the Silica Content of Diatoms on Protozoan Grazing

    Directory of Open Access Journals (Sweden)

    Shuwen Zhang

    2017-06-01

    Full Text Available This study examined the effect that silica content in diatom cells has on the behavior of protists. The diatoms Thalassiosira weissflogii and T. pseudonana were cultured in high or low light conditions to achieve low and high silica contents, respectively. These cells were then fed to a heterotrophic dinoflagellate Noctiluca scintillans and a ciliate Euplotes sp. in single and mixed diet experiments. Our results showed that in general, N. scintillans and Euplotes sp. both preferentially ingested the diatoms with a low silica content rather than those with a high silica content. However, Euplotes sp. seemed to be less influenced by the silica content than was N. scintillans. In the latter case, the clearance and ingestion rate of the low silica diatoms were significantly higher, both in the short (6-h and long (1-d duration grazing experiments. Our results also showed that N. scintillans required more time to digest the high silica-containing cells. As the high silica diatoms are harder to digest, this might explain why N. scintillans exhibits a strong preference for the low silica prey. Thus, the presence of high silica diatoms might limit the ability of the dinoflagellate to feed. Our findings suggest that the silica content of diatoms affects their palatability and digestibility and, consequently, the grazing activity and selectivity of protozoan grazers.

  17. Nutrient removal by prairie filter strips in agricultural landscapes

    Science.gov (United States)

    X. Zhou; M.J. Helmers; H. Asbjornsen; R. Kolka; M.D. Tomer; R.M. Cruse

    2014-01-01

    Nitrogen (N) and phosphorus (P) from agricultural landscapes have been identified as primary sources of excess nutrients in aquatic systems. The main objective of this study was to evaluate the effectiveness of prairie filter strips (PFS) in removing nutrients from cropland runoff in 12 small watersheds in central Iowa. Four treatments with PFS of different spatial...

  18. Resistance to plague among black-tailed prairie dog populations

    Science.gov (United States)

    Rocke, Tonie E.; Williamson, Judy; Cobble, Kacy R.; Busch, Joseph D.; Antolin, Michael F.; Wagner, David M.

    2012-01-01

    In some rodent species frequently exposed to plague outbreaks caused by Yersinia pestis, resistance to the disease has evolved as a population trait. As a first step in determining if plague resistance has developed in black-tailed prairie dogs (Cynomys ludovicianus), animals captured from colonies in a plague-free region (South Dakota) and two plague-endemic regions (Colorado and Texas) were challenged with Y. pestis at one of three doses (2.5, 250, or 2500 mouse LD50s). South Dakota prairie dogs were far more susceptible to plague than Colorado and Texas prairie dogs (pdogs were quite similar in their response, with overall survival rates of 50% and 60%, respectively. Prairie dogs from these states were heterogenous in their response, with some animals dying at the lowest dose (37% and 20%, respectively) and some surviving even at the highest dose (29% and 40%, respectively). Microsatellite analysis revealed that all three groups were distinct genetically, but further studies are needed to establish a genetic basis for the observed differences in plague resistance.

  19. Food habits of nesting prairie falcons in Campbell County

    Science.gov (United States)

    John R. Squires; Stanley H. Anderson; Robert Oakleaf

    1989-01-01

    Fifteen species of prey were utilized by nesting Prairie Falcons (Falco mexicanus) as determined through pellet analysis. Thirteen-lined Ground Squirrels (Spermophilus tridecemlineatus), the most common prey, were present in 91% of the pellets, followed by Western Meadowlarks (Sturnella neglecta) which were present in 56% of pellets. Horned Larks (Eremophila...

  20. Prairie Restoration Project: Alternatives for Identifying Gifted Students

    Science.gov (United States)

    Salisbury, Katie E.; Rule, Audrey C.; Vander Zanden, Sarah M.

    2016-01-01

    An authentic, challenging curriculum engaged middle school students from an urban district in exploratory work related to restoring a small prairie at the school. Integrated science-literacy-arts activities were coupled with a system of thinking skills that helped students view issues from different perspectives. Impassioned guest speakers and an…

  1. Overview of Prairie Planting Techniques and Maintenance Requirements

    Science.gov (United States)

    2007-02-01

    districts have these drills 6 ERDC TN-EMRRP-ER-05 February 2007 available for rent. A three-point broadcast seeder or a fertilizer spreader can...lengthens the growing season for prairie plants but shortens it for many weedy species (Pauly 1997). Fire allows for nutrient recycling in the ecosystem by

  2. Selected hydrologic data, Camas Prairie, south-central Idaho

    Science.gov (United States)

    Young, H.W.; Backsen, R.L.; Kenyon, K.S.

    1978-01-01

    This report presents data collected during a 1-year study of the water resources of Camas Prairie, Idaho. Included are records of wells, discharge measurements of streams, hydrographs of water levels in wells, water-quality data, and drillers ' logs of wells. The data are conveniently made available to supplement an interpretive report, which will be published separately. (Woodard-USGS)

  3. Camel spider (Solifugae) use of prairie dog colonies

    Science.gov (United States)

    Solifugids (camel spiders) are widespread throughout arid regions of western North America and are thought to be important in structuring desert arthropod communities. Despite the ubiquity of camel spiders, little is known about their ecology. Black-tailed prairie dogs (Cynomys ludovicianus) are als...

  4. Grazing-incident PIXE Analysis Technology

    International Nuclear Information System (INIS)

    Li Hongri; Wang Guangpu; Liang Kun; Yang Ru; Han Dejun

    2009-01-01

    In the article, the grazing incidence technology is first applied to the PIXE (proton induced X-ray emission) analysis. Three pieces of samples were investigated, including the contaminated aluminium substrate, the SIMOX (separated by oxygen implantation) SOI (Silicon on Insulator) sample and the silicon wafer implanted with Fe + . The results reveal that the grazing-incident proton can improve the sensitivity of PIXE in trace analysis, especially for samples contaminated on surface. With the penetration depth of the proton bean decreased, the ratio of the peak area to the detection limit raised observably and the sensitivity near the sample surface increased. (authors)

  5. Recommended methods for range-wide monitoring of prairie dogs in the United States

    Science.gov (United States)

    McDonald, Lyman L.; Stanley, Thomas R.; Otis, David L.; Biggins, Dean E.; Stevens, Patricia D.; Koprowski, John L.; Ballard, Warren

    2011-01-01

    One of the greatest challenges for conserving grassland, prairie scrub, and shrub-steppe ecosystems is maintaining prairie dog populations across the landscape. Of the four species of prairie dogs found in the United States, the Utah prairie dog (Cynomys parvidens) is listed under the Endangered Species Act (ESA) as threatened, the Gunnison's prairie dog (C. gunnisoni) is a candidate for listing in a portion of its range, and the black-tailed prairie dog (C. ludovicianus) and white-tailed prairie dog (C. leucurus) have each been petitioned for listing at least once in recent history. Although the U.S. Fish and Wildlife Service (USFWS) determined listing is not warranted for either the black-tailed prairie dog or white-tailed prairie dog, the petitions and associated reviews demonstrated the need for the States to monitor and manage for self-sustaining populations. In response to these findings, a multi-State conservation effort was initiated for the nonlisted species which included the following proposed actions: (1) completing an assessment of each prairie dog species in each State, (2) developing a range-wide monitoring protocol for each species using a statistically valid sampling procedure that would allow comparable analyses across States, and (3) monitoring prairie dog status every 3-5 years depending upon the species. To date, each State has completed an assessment and currently is monitoring prairie dog status; however, for some species, the inconsistency in survey methodology has made it difficult to compare data year-to-year or State-to-State. At the Prairie Dog Conservation Team meeting held in November 2008, there was discussion regarding the use of different methods to survey prairie dogs. A recommendation from this meeting was to convene a panel in a workshop-type forum and have the panel review the different methods being used and provide recommendations for range-wide monitoring protocols for each species of prairie dog. Consequently, the Western

  6. Modeling the grazing effect on dry grassland carbon cycling with modified Biome-BGC grazing model

    Science.gov (United States)

    Luo, Geping; Han, Qifei; Li, Chaofan; Yang, Liao

    2014-05-01

    Identifying the factors that determine the carbon source/sink strength of ecosystems is important for reducing uncertainty in the global carbon cycle. Arid grassland ecosystems are a widely distributed biome type in Xinjiang, Northwest China, covering approximately one-fourth the country's land surface. These grasslands are the habitat for many endemic and rare plant and animal species and are also used as pastoral land for livestock. Using the modified Biome-BGC grazing model, we modeled carbon dynamics in Xinjiang for grasslands that varied in grazing intensity. In general, this regional simulation estimated that the grassland ecosystems in Xinjiang acted as a net carbon source, with a value of 0.38 Pg C over the period 1979-2007. There were significant effects of grazing on carbon dynamics. An over-compensatory effect in net primary productivity (NPP) and vegetation carbon (C) stock was observed when grazing intensity was lower than 0.40 head/ha. Grazing resulted in a net carbon source of 23.45 g C m-2 yr-1, which equaled 0.37 Pg in Xinjiang in the last 29 years. In general, grazing decreased vegetation C stock, while an increasing trend was observed with low grazing intensity. The soil C increased significantly (17%) with long-term grazing, while the soil C stock exhibited a steady trend without grazing. These findings have implications for grassland ecosystem management as it relates to carbon sequestration and climate change mitigation, e.g., removal of grazing should be considered in strategies that aim to increase terrestrial carbon sequestrations at local and regional scales. One of the greatest limitations in quantifying the effects of herbivores on carbon cycling is identifying the grazing systems and intensities within a given region. We hope our study emphasizes the need for large-scale assessments of how grazing impacts carbon cycling. Most terrestrial ecosystems in Xinjiang have been affected by disturbances to a greater or lesser extent in the past

  7. Effect of grazing frequency and intensity on Lolium perenne L ...

    African Journals Online (AJOL)

    ) system. Low frequency, low intensity grazing produced lower CDMD and herbage N levels than higher grazing frequencies and intensities. These differences were, however, generally small. Overall, levels of herbage digestibility (estimated ...

  8. Diets of swift foxes (Vulpes velox) in continuous and fragmented prairie in Northwestern Texas

    Science.gov (United States)

    Kamler, J.F.; Ballard, W.B.; Wallace, M.C.; Gipson, P.S.

    2007-01-01

    Distribution of the swift fox (Vulpes velox) has declined dramatically since the 1800s, and suggested causes of this decline are habitat fragmentation and transformation due to agricultural expansion. However, impacts of fragmentation and human-altered habitats on swift foxes still are not well understood. To better understand what effects these factors have on diets of swift foxes, scats were collected in northwestern Texas at two study sites, one of continuous native prairie and one representing fragmented native prairie interspersed with agricultural and fields in the Conservation Reserve Program. Leporids, a potential food source, were surveyed seasonally on both sites. Diets of swift foxes differed between sites; insects were consumed more on continuous prairie, whereas mammals, birds, and crops were consumed more on fragmented prairie. Size of populations of leporids were 2-3 times higher on fragmented prairie, and swift foxes responded by consuming more leporids on fragmented (11.1% frequency occurrence) than continuous (3.8%) prairie. Dietary diversity was greater on fragmented prairie during both years of the study. Differences in diets between sites suggested that the swift fox is an adaptable and opportunistic feeder, able to exploit a variety of food resources, probably in relation to availability of food. We suggest that compared to continuous native prairie, fragmented prairie can offer swift foxes a more diverse prey base, at least within the mosaic of native prairie, agricultural, and fields that are in the Conservation Reserve Program.

  9. Physiological-metabolic variables of heat stress in cows grazing in silvopastoral systems and in one treeless prairie.

    Directory of Open Access Journals (Sweden)

    Wilson Andrés Berragán-Hernández

    2015-06-01

    Full Text Available The aim of this work was to analyze changes of physiological and metabolic parameters as indicators of heat stress of cows in pasture systems. The research was carried out from 2011 to 2012 at the Turipaná Agricultural Research Center of Corpoica located in the Caribbean region in Cereté–Colombia. Environmental temperature (T and relative humidity (H were determined, as well as and rectal temperature (RT, skin temperature (ST, respiratory frequency (RF and the acid-basic status of animals. The variables were measured in the morning (6:00 h and in the afternoon (13:00 h. Significant Statistical differences were observed (p<0.05 in environmental temperature treatments (T with 7% and 6% less temperature in p-Arbus-Arbor y p-Arbor, respectively, compared with grass treatment. There was a significant hour effect on T and H (p<0.05 and a significant treatment-hour interaction on T (p<0.05. TP and FR showed a significant treatment-hour interaction per hour (6:00/13:00 h. The results show a positive effect of shadow from trees on the physiological variables. The negative effects observed on the physiological variables of unshaded treatments impacted in a minimal way the metabolic variables suggesting homeostatic responses in the animals under the evaluated stressful environmental conditions.

  10. A review of experiments comparing systems of grazing management ...

    African Journals Online (AJOL)

    Experiments comparing different systems of grazing management on natural pastures in various parts of the world are reviewed. In experiments in which various rotational systems were tested against continuous grazing, fewer than half revealed pasture improvement relative to continuous grazing. In the majority of ...

  11. Performance and Grazing Pattern of West African Dwarf Sheep to ...

    African Journals Online (AJOL)

    Sixty (60) West African Dwarf sheep managed semi intensively and grazing on natural pastures were used in a study to determine the performance and grazing pattern to seasonal forage supply and quality. The animals were allowed to graze for about 6 hours daily for four months each in the dry and wet seasons, ...

  12. How Does “Hunger” Level Impact Grazing Behavior?

    Science.gov (United States)

    Grazing behavior can be influenced through feeding and grazing management decisions. Research at our USDA-ARS lab showed that ruminal fill, or how ‘hungry’ the cow is, can affect grazing behavior. Cows that had less ruminal fill took a bigger bite that was shallow and wide, compared to a ‘full’ cow ...

  13. Longer rest periods for intensive rotational grazing limit diet quality ...

    African Journals Online (AJOL)

    Longer rest periods for intensive rotational grazing limit diet quality of sheep without enhancing environmental benefits. ... This experiment was established to compare three intensive rotational grazing strategies (fast rotation [FR], average 57-day rest; slow rotation [SR], average 114-day rest; and flexible grazing [FX], based ...

  14. Forage patch use by grazing herbivores in a South African grazing ecosystem

    NARCIS (Netherlands)

    Venter, J.A.; Nabe-Nielsen, J.; Prins, H.H.T.; Slotow, R.

    2014-01-01

    Understanding how different herbivores make forage patch use choices explains how they maintain an adequate nutritional status, which is important for effective conservation management of grazing ecosystems. Using telemetry data, we investigated nonruminant zebra (Equus burchelli) and ruminant red

  15. Grazing incidence polarized neutron scattering in reflection ...

    Indian Academy of Sciences (India)

    journal of. January 2012 physics pp. 1–58. Grazing incidence polarized ..... atomic distances, the neutron has an energy which is low compared to molecular binding ...... cores and that of the Co ions in the AF oxide coatings. ...... [32] C Leighton, M R Fitzsimmons, P Yashar, A Hoffmann, J Nogus, J Dura, C F Majkrzak and.

  16. Dietary selection by steers grazing kikuyu

    African Journals Online (AJOL)

    being grazeA for a period of 3,5 days in a four-week rotation, at ... Cattle improve the quality of their diet by actively seeking ... of stem in their diet. This would explain why the stem fraction mad~ no significant contribution to the equation predicting diet~ry selection. A:1unusual fact which emerged is that the animals selected.

  17. 25 CFR 700.722 - Grazing associations.

    Science.gov (United States)

    2010-04-01

    ... recognition by the Commissioner are: (1) The members of the association must be grazing permittees and.... (d) The Commissioner may withdraw his recognition of the association whenever: (1) The majority of... constitution and bylaws. All of the association's livestock will be run under an association brand properly...

  18. Grazing management for Nordic organic dairy farming

    OpenAIRE

    Kuusela, Eeva

    2005-01-01

    The aims of this study were to identify limiting factors and to develop adjusted grazing management for Nordic organic dairy farming conditions. The focus was to combine the aspects of plant, animal and organic production, as they are all involved in organic dairy pastures.

  19. Phosphorus supplementation of Karakul sheep grazing natural ...

    African Journals Online (AJOL)

    The phosphorus (P) status of adult Karakul ewes grazing natural pasture was determined by measuring the P content of blood, saliva, faecal, and bone samples. The ewes were divided into four groups of 20 ewes each, viz. ewes supplemented with P+ and P- which lambed during May and October. All lambs born were ...

  20. Woodlands Grazing Issues in Mediterranean Basin

    Science.gov (United States)

    Campos, P.

    2009-04-01

    In Mediterranean basin, woodlands grazing still continue to be important commercial owners' benefits. These owners manage woodlands vegetations as if they were not at risk of degradation and declining. Frequently, no temporally grazing set-aside is taken into account to avoid overgrazing of annual and perennial vegetations. Although less common, in the northern shore of Mediterranean basin undergrazing might increase the frequency and the number of catastrophic forest fires. This under/over grazing regime occurs in the Mediterranean basin woodlands with contrasted differences on land property rights, local economies and government livestock policy incentives. Spain and Tunisia are examples of these Mediterranean livestock contrasts. Most of Spanish Mediterranean woodlands and livestock herds are large private ownerships and owners could maintain their lands and livestock herds properties on the basis of moderate cash-income compensation against land revaluation and exclusive amenity self-consumption. The later is less tangible benefit and it could include family land legacy, nature enjoyment, country stile of life development, social status and so on. In public woodlands, social and environmental goals -as they are cultural heritage, biodiversity loss mitigation, soil conservation and employment- could maintain market unprofitable woodlands operations. Last three decades Spanish Mediterranean woodlands owners have increased the livestock herds incentivized by government subsidies. As result, grazing rent is pending on the level of European Union and Spanish government livestock subsidies. In this context, Spanish Mediterranean woodlands maintain a high extensive livestock stoking population, which economy could be called fragile and environmentally unsustainable because forest degradation and over/under grazing practices. Tunisian Mediterranean woodlands are state properties and livestock grazing is practice as a free private regimen. Livestock herds are small herd

  1. The influence of cattle grazing and grass seeding on coniferous regeneration after shelterwood cutting in eastern Oregon.

    Science.gov (United States)

    K.W. Seidel; J. Michael Geist; Gerald S. Strickler

    1990-01-01

    Natural regeneration was abundant, regardless of grazing and grass seeding treatments,after shelterwood cutting to three overstory densities (27, 73, and 119 square feet of basal area per acre) in mixed conifer stands in the Starkey Experimental Forest and Range in eastern Oregon. After 6 years, the number of tree seedlings ranged from about 3,800 per acre on the low-...

  2. Bivalve grazing can shape phytoplankton communities

    Science.gov (United States)

    Lucas, Lisa; Cloern, James E.; Thompson, Janet K.; Stacey, Mark T.; Koseff, Jeffrey K.

    2016-01-01

    The ability of bivalve filter feeders to limit phytoplankton biomass in shallow waters is well-documented, but the role of bivalves in shaping phytoplankton communities is not. The coupled effect of bivalve grazing at the sediment-water interface and sinking of phytoplankton cells to that bottom filtration zone could influence the relative biomass of sinking (diatoms) and non-sinking phytoplankton. Simulations with a pseudo-2D numerical model showed that benthic filter feeding can interact with sinking to alter diatom:non-diatom ratios. Cases with the smallest proportion of diatom biomass were those with the fastest sinking speeds and strongest bivalve grazing rates. Hydrodynamics modulated the coupled sinking-grazing influence on phytoplankton communities. For example, in simulations with persistent stratification, the non-sinking forms accumulated in the surface layer away from bottom grazers while the sinking forms dropped out of the surface layer toward bottom grazers. Tidal-scale stratification also influenced vertical gradients of the two groups in opposite ways. The model was applied to Suisun Bay, a low-salinity habitat of the San Francisco Bay system that was transformed by the introduction of the exotic clam Potamocorbula amurensis. Simulation results for this Bay were similar to (but more muted than) those for generic habitats, indicating that P. amurensis grazing could have caused a disproportionate loss of diatoms after its introduction. Our model simulations suggest bivalve grazing affects both phytoplankton biomass and community composition in shallow waters. We view these results as hypotheses to be tested with experiments and more complex modeling approaches.

  3. Grazing livestock are exposed to terrestrial cyanobacteria.

    Science.gov (United States)

    McGorum, Bruce C; Pirie, R Scott; Glendinning, Laura; McLachlan, Gerry; Metcalf, James S; Banack, Sandra A; Cox, Paul A; Codd, Geoffrey A

    2015-02-25

    While toxins from aquatic cyanobacteria are a well-recognised cause of disease in birds and animals, exposure of grazing livestock to terrestrial cyanobacteria has not been described. This study identified terrestrial cyanobacteria, predominantly Phormidium spp., in the biofilm of plants from most livestock fields investigated. Lower numbers of other cyanobacteria, microalgae and fungi were present on many plants. Cyanobacterial 16S rDNA, predominantly from Phormidium spp., was detected in all samples tested, including 6 plant washings, 1 soil sample and ileal contents from 2 grazing horses. Further work was performed to test the hypothesis that ingestion of cyanotoxins contributes to the pathogenesis of some currently unexplained diseases of grazing horses, including equine grass sickness (EGS), equine motor neuron disease (EMND) and hepatopathy. Phormidium population density was significantly higher on EGS fields than on control fields. The cyanobacterial neurotoxic amino acid 2,4-diaminobutyric acid (DAB) was detected in plant washings from EGS fields, but worst case scenario estimations suggested the dose would be insufficient to cause disease. Neither DAB nor the cyanobacterial neurotoxins β-N-methylamino-L-alanine and N-(2-aminoethyl) glycine were detected in neural tissue from 6 EGS horses, 2 EMND horses and 7 control horses. Phormidium was present in low numbers on plants where horses had unexplained hepatopathy. This study did not yield evidence linking known cyanotoxins with disease in grazing horses. However, further study is warranted to identify and quantify toxins produced by cyanobacteria on livestock fields, and determine whether, under appropriate conditions, known or unknown cyanotoxins contribute to currently unexplained diseases in grazing livestock.

  4. Effects of co-grazing dairy heifers with goats on animal performance, dry matter yield, and pasture forage composition.

    Science.gov (United States)

    Dennis, T S; Unruh-Snyder, L J; Neary, M K; Nennich, T D

    2012-12-01

    Mixed livestock grazing can offer an alternative management system for rearing dairy replacement heifers (Bos taurus). A 2-yr study was conducted during 2009 (yr 1) and 2010 (yr 2) to determine the effects of co-grazing Holstein heifers under rotational stocking with Boer × Kiko goats on animal performance, pasture DM yield, and botanical composition. Each year, 24 heifers (134 ± 6 d of age and 147.4 ± 31.2 kg BW in yr 1; 166 ± 11 d of age and 168.0 ± 27.6 kg BW in yr 2) and 6 goats (2 yr old and 39.7 ± 16.2 kg BW in yr 1; 1 yr old and 33.7 ± 7.4 kg BW in yr 2) were divided into 6 paddocks with 4 heifers and 2 goats, where applicable, per group. Low endophyte-infected tall fescue (Festuca arundinacea Schreb.) and white clover (Trifolium repens L.) pastures were used to evaluate 2 grazing strategies (heifers grazed alone [HO] or heifers co-grazed with goats [HG]). In addition, 6 goats were assigned to 2 paddocks and grazed alone (GO) each year to estimate goat pasture forage intake and compare Haemonchus contortus infection to co-grazed goats. Forage samples were taken monthly to assess DM yield and botanical composition. Samples collected for botanical composition were manually sorted into grass, legume, and weed species. Forage DMI was estimated using a rising plate meter before and after grazing. Heifer BW at the conclusion of yr 1 and yr 2 did not differ between HO and HG (P = 0.40 and P = 0.12, respectively). Likewise, overall ADG did not differ between HO and HG, averaging 0.65 kg/d and 0.63 kg/d over both grazing seasons (P = 0.70). Grazing strategy did not affect forage or total DMI in yr 1; however, HO consumed 2.3 kg/d more forage DM than HG (P pastures (P dairy heifers can be co-grazed with goats without negative effects on ADG or feed efficiency.

  5. The impact of sheep grazing on the carbon balance of a peatland

    Energy Technology Data Exchange (ETDEWEB)

    Worrall, Fred, E-mail: Fred.Worrall@durham.ac.uk; Clay, Gareth D.

    2012-11-01

    Estimates of the greenhouse gas (GHG) fluxes resulting from sheep grazing upon upland peat soils have never been fully quantified. Previous studies have been limited to individual flux pathways or to comparing the presence to the absence of sheep grazing. Therefore, this study combines a model of the physical impact of grazing with models of: biomass production; energy usage in sheep; and peat accumulation. These combined modelling approaches enabled this study to consider the indirect and direct impacts of sheep upon the carbon and greenhouse gas balance of a peatland at different grazing intensities as well as the changes between grazing intensities. The study considered four vegetation scenarios (Calluna sp., Molinia sp.; reseeded grasses, and Agrostis-Festuca grassland) and a mixed vegetation scenario based upon the vegetation typical of upland peat ecosystems in northern England. Each scenario was considered for altitudes between 350 and 900 m above sea level and for grazing intensities between 0.1 and 2 ewes/ha. The study can show that the total GHG flux at the vegetative carrying capacity tended to decline with increasing altitude for all vegetation scenarios considered except for Molinia sp. The average total GHG flux for all scenarios was 1505 kg CO{sub 2}eq/ha/yr/(ewe/ha), and on average 89% of the fluxes were directly from the sheep and not from the soil, and are therefore not unique to a peat soil environment. The study suggests that emission factors for upland sheep have been greatly underestimated. By comparing the total flux due to grazers to the flux to or from the soil that allows the study to define a GHG carry capacity, i.e. the grazing intensity at which the flux due to grazing is equal to the sink represented by the peat soils, this GHG carrying capacity varies between 0.2 and 1.7 ewes/ha with this capacity declining with increasing altitude for all model scenarios. -- Highlights: Black-Right-Pointing-Pointer Vegetative carrying capacity was

  6. 25 CFR 166.307 - Will the grazing capacity be increased if I graze adjacent trust or non-trust rangelands not...

    Science.gov (United States)

    2010-04-01

    ... § 166.307 Will the grazing capacity be increased if I graze adjacent trust or non-trust rangelands not... trust or non-trust rangeland in common with the permitted land. Grazing capacity will be established... 25 Indians 1 2010-04-01 2010-04-01 false Will the grazing capacity be increased if I graze...

  7. Response of mountain meadows to grazing by recreational pack stock

    Science.gov (United States)

    Cole, David N.; Van Wagtendonk, Jan W.; McClaran, Mitchel P.; Moore, Peggy E.; McDougald, Neil K.

    2004-01-01

    Effects of recreational pack stock grazing on mountain meadows in Yosemite National Park were assessed in a 5-year study. Yosemite is a designated wilderness, to be managed such that its natural conditions are preserved. Studies were conducted in 3 characteristic meadow types: shorthair sedge (Carex filifolia Nutt.), Brewer's reed grass (Calamagrostis breweri Thurber), and tufted hairgrass [Deschampsia cespitosa (L.) Beauv.]. Horses and mules grazed experimental plots at intensities of 15 to 69% utilization for 4 seasons. In all 3 meadows, grazing caused decreases in productivity. The mean reduction after 4 years of grazing was 18% in the shorthair sedge meadow, 17% in the Brewer's reed grass meadow, and 22% in the tufted hairgrass meadow. Grazing also caused shifts in basal groundcover (usually a reduction in vegetation cover and increase in bare soil cover), and changes in species composition. Productivity and vegetation cover decreased as percent utilization increased, while bare soil cover increased as utilization increased. Changes in species composition were less predictably related to differences in grazing intensity. Passive management of grazing is insufficient in wilderness areas that are regularly used by groups with recreational stock. Wilderness managers need to monitor meadow conditions and the grazing intensities that occur. Our study suggests that biomass and ground cover are more sensitive indicators of grazing impact than species composition. Managers must make decisions about maximum acceptable levels of grazing impact and then develop guidelines for maximum use levels, based on data such as ours that relates grazing intensity to meadow response.

  8. Avoidance behavior by prairie grouse: implications for development of wind energy.

    Science.gov (United States)

    Pruett, Christin L; Patten, Michael A; Wolfe, Donald H

    2009-10-01

    New wind-energy facilities and their associated power transmission lines and roads are being constructed at a rapid pace in the Great Plains of North America. Nevertheless, little is known about the possible negative effects these anthropogenic features might have on prairie birds, one of the most threatened groups in North America. We examined radiotelemetry tracking locations of Lesser Prairie-Chickens (Tympanuchus pallidicinctus) and Greater Prairie-Chickens (T. cupido) in two locations in Oklahoma to determine whether these birds avoided or changed movement behavior near power lines and paved highways. We tracked 463 Lesser Prairie-Chickens (15,071 tracking locations) and 216 Greater Prairie-Chickens (5,750 locations) for 7 and 3 years, respectively. Individuals of both species avoided power lines by at least 100 m and Lesser Prairie-Chickens avoided one of the two highways by 100 m. Prairie-chickens crossed power lines less often than expected if birds moved randomly (p 0.05). In addition, home ranges of Lesser Prairie-Chickens overlapped the power line less often than would be expected by chance placement of home ranges; this result was supported by kernel-density estimation of home ranges. It is likely that new power lines (and other tall structures such as wind turbines) will lead to avoidance of previously suitable habitat and will serve as barriers to movement. These two factors will likely increase fragmentation in an already fragmented landscape if wind energy development continues in prairie habitats.

  9. Reduction of neonicotinoid insecticide residues in Prairie wetlands by common wetland plants.

    Science.gov (United States)

    Main, Anson R; Fehr, Jessica; Liber, Karsten; Headley, John V; Peru, Kerry M; Morrissey, Christy A

    2017-02-01

    Neonicotinoid insecticides are frequently detected in wetlands during the early to mid-growing period of the Canadian Prairie cropping season. These detections also overlap with the growth of macrophytes that commonly surround agricultural wetlands which we hypothesized may reduce neonicotinoid transport and retention in wetlands. We sampled 20 agricultural wetlands and 11 macrophyte species in central Saskatchewan, Canada, over eight weeks to investigate whether macrophytes were capable of reducing movement of neonicotinoids from cultivated fields and/or reducing concentrations in surface water by accumulating insecticide residues into their tissues. Study wetlands were surrounded by clothianidin-treated canola and selected based on the presence (n=10) or absence (n=10) of a zonal plant community. Neonicotinoids were positively detected in 43% of wetland plants, and quantified in 8% of all plant tissues sampled. Three plant species showed high rates of detection: 78% Equisetum arvense (clothianidin, range: wetlands had higher detection frequency and water concentrations of clothianidin (β±S.E.: -0.77±0.26, P=0.003) and thiamethoxam (β±S.E.: -0.69±0.35, P=0.049) than vegetated wetlands. We assessed the importance of wetland characteristics (e.g. vegetative zone width, emergent plant height, water depth) on neonicotinoid concentrations in Prairie wetlands over time using linear mixed-effects models. Clothianidin concentrations were significantly lower in wetlands surrounded by taller plants (β±S.E.: -0.57±0.12, P≤0.001). The results of this study suggest that macrophytes can play an important role in mitigating water contamination by accumulating neonicotinoids and possibly slowing transport to wetlands during the growing season. Copyright © 2016 Elsevier B.V. All rights reserved.

  10. Climate impacts on the agribusiness sectors of a prairie economy

    International Nuclear Information System (INIS)

    Arthur, L.M.; Kooten, G.C. Van.

    1992-01-01

    Global warming is likely to result in increased agricultural output on the Canadian prairies. However, using input-output analysis, it is shown that the potential impact of global warming on agribusiness, while significant, is both uncertain and relatively small compared to the impact of government agricultural policies pertaining to the grain and livestock sectors. Furthermore, caution is required in deciding whether or not western Canada and prairie agribusinesses are net beneficiaries of a greenhouse effect because climate-induced changes in agricultural output elsewhere in the world still need to be taken into account. Most previous studies on American and European agriculture under the greenhouse effect predict reduced yields of current crops, which could mean improved markets for Canadian crops. 27 refs., 4 figs., 2 tabs

  11. Effects of grazing and feedlot finishing duration on the performance of three beef cattle genotypes in Uganda

    DEFF Research Database (Denmark)

    Asizua, Denis; Mpairwe, Denis; Kabi, Fred

    2017-01-01

    genotype (212±35 kg). The bulls were allotted to two feeding systems and three finishing durations. The feeding systems comprised sole grazing as the control where animals only grazed natural pastures and feedlot finishing where animals were fed a locally formulated total mixed ration containing 200 maize...... stover, 300 maize bran, 447 brewers’ spent grain, 50 molasses and 3 salt (NaCl) as g/kg on dry matter (DM) basis. The three durations were 60, 90 and 120 days excluding 14 days of adaptation period. Data was collected on feed intake, growth, slaughter and carcass characteristics. The Boran consumed less....... However, carcass quality grade scores were higher (Pcarcass...

  12. A meta-analysis of lesser prairie-chicken nesting and brood-rearing habitats: implications for habitat management

    Science.gov (United States)

    Hagen, Christian A.; Grisham, Blake A.; Boal, Clint W.; Haukos, David A.

    2013-01-01

    The distribution and range of lesser prairie-chicken (Tympanuchus pallidicinctus) has been reduced by >90% since European settlement of the Great Plains of North America. Currently, lesser prairie-chickens occupy 3 general vegetation communities: sand sagebrush (Artemisia filifolia), sand shinnery oak (Quercus havardii), and mixed-grass prairies juxtaposed with Conservation Reserve Program grasslands. As a candidate for protection under the Endangered Species Act, there is a need for a synthesis that characterizes habitat structure rangewide. Thus, we conducted a meta-analysis of vegetation characteristics at nest sites and brood habitats to determine whether there was an overall effect (Hedges' d) of habitat selection and to estimate average (95% CI) habitat characteristics at use sites. We estimated effect sizes (di) from the difference between use (nests and brood sites) and random sampling sites for each study (n = 14), and derived an overall effect size (d++). There was a general effect for habitat selection as evidenced by low levels of variation in effect sizes across studies and regions. There was a small to medium effect (d++) = 0.20-0.82) of selection for greater vertical structure (visual obstruction) by nesting females in both vegetation communities, and selection against bare ground (d++ = 0.20-0.58). Females with broods exhibited less selectivity for habitat components except for vertical structure. The variation of d++ was greater during nesting than brooding periods, signifying a seasonal shift in habitat use, and perhaps a greater range of tolerance for brood-rearing habitat. The overall estimates of vegetation cover were consistent with those provided in management guidelines for the species.

  13. Prairie rattlesnake envenomation in 27 New World camelids.

    Science.gov (United States)

    Sonis, J M; Hackett, E S; Callan, R J; Holt, T N; Hackett, T B

    2013-01-01

    Morbidity and case fatality from rattlesnake envenomation is regionally specific because of variability in relative toxicity of the species of snake encountered. A previous report of rattlesnake envenomation in New World camelids (NWC) from the western coastal United States documented high case fatality rates and guarded prognosis for survival. To describe clinical findings, treatments, and outcome of NWC with prairie rattlesnake (Crotalus viridis viridis) envenomation in the Rocky Mountain region of the United States. Twenty-seven NWC admitted to the Colorado State University Veterinary Teaching Hospital for evaluation of acute rattlesnake envenomation between 1992 and 2012. Medical records of NWC evaluated for rattlesnake envenomation as coded by the attending clinician and identified by a database search were reviewed retrospectively. Month of admission, signalment, area of bite, clinical and clinicopathologic data, treatments, and outcome were recorded. Twenty-five llamas and 2 alpacas were admitted for envenomation. Llamas were overrepresented compared to hospital caseload. The face was the most common site of envenomation, observed in 96% of recorded cases. Presenting clinical signs included fever, tachypnea, tachycardia, and respiratory distress. Nine animals required a tracheotomy. Median hospitalization time was 3 days and overall survival rate was 69%. Case fatality rate for prairie rattlesnake envenomation in NWC was lower than that reported in the Western coastal region of the United States and similar to that reported for prairie rattlesnake envenomation in horses. Copyright © 2013 by the American College of Veterinary Internal Medicine.

  14. Resting state brain networks in the prairie vole.

    Science.gov (United States)

    Ortiz, Juan J; Portillo, Wendy; Paredes, Raul G; Young, Larry J; Alcauter, Sarael

    2018-01-19

    Resting state functional magnetic resonance imaging (rsfMRI) has shown the hierarchical organization of the human brain into large-scale complex networks, referred as resting state networks. This technique has turned into a promising translational research tool after the finding of similar resting state networks in non-human primates, rodents and other animal models of great value for neuroscience. Here, we demonstrate and characterize the presence of resting states networks in Microtus ochrogaster, the prairie vole, an extraordinary animal model to study complex human-like social behavior, with potential implications for the research of normal social development, addiction and neuropsychiatric disorders. Independent component analysis of rsfMRI data from isoflurane-anestethized prairie voles resulted in cortical and subcortical networks, including primary motor and sensory networks, but also included putative salience and default mode networks. We further discuss how future research could help to close the gap between the properties of the large scale functional organization and the underlying neurobiology of several aspects of social cognition. These results contribute to the evidence of preserved resting state brain networks across species and provide the foundations to explore the use of rsfMRI in the prairie vole for basic and translational research.

  15. Interspecific nutrient transfer in a tallgrass prairie plant community

    International Nuclear Information System (INIS)

    Walter, L.E.F.; Hartnett, D.C.; Hetrick, B.A.D.; Schwab, A.P.

    1996-01-01

    Interplant nutrient transfer may be an important ecological process in grasslands, and may significantly influence plant neighborhood interactions. We investigated the potential for phosphorus transfer between the dominant grass Andropogon gerardii and several neighboring plant species in tallgrass prairie via a field 32PO4 labelling experiment. The mean amount of 32P received from donor shoots differed significantly among neighboring species and decreased with increasing distance from the donor. In general, forbs and cool-season C3 grasses received more labelled 32P than warm-season C4 grasses. Phosphorus transfer occurred over distances up to 0.5 m. The effects of species and distance on movement of phosphorus changed with increasing time after labelling. The relative mass of receiver and donor shoots did not affect amounts of 32P transfer. A benomyl fungicide treatment, applied to suppress mycorrhizal activity, likely did not affect existing vegetative hyphae and did not affect the amount of 32P transferred. These studies demonstrate that: (1) phosphorus is transferred among neighboring species in tallgrass prairie plant communities, (2) phosphorus may be transferred over significantly greater distances than reported in other grasslands, and (3) there is differential transfer among co-occurring species. Hypothesized mechanisms accounting for these patterns in tallgrass prairie include mycorrhizal hyphal interconnections and/or extensive and differential root and rhizosphere overlap among neighboring species

  16. The current status of grazing incidence optics

    International Nuclear Information System (INIS)

    Aschenbach, B.

    1983-01-01

    The developments in the area of grazing incidence optics with emphasis on telescopes for use in X-ray astronomy are reviewed. The performance of existing high-resolution telescopes is outlined and compared with those expected from future missions like ROSAT and AXAF. Starting from the basic principles of X-ray reflection and scattering, an attempt is made to highlight the current understanding of X-ray mirror physics using new theoretical ideas as well as experimental laboratory results. (author)

  17. Seasonality constraints to livestock grazing intensity.

    Science.gov (United States)

    Fetzel, Tamara; Havlik, Petr; Herrero, Mario; Erb, Karl-Heinz

    2017-04-01

    Increasing food production is essential to meet the future food demand of a growing world population. In light of pressing sustainability challenges such as climate change and the importance of the global livestock system for food security as well as GHG emissions, finding ways to increasing food production sustainably and without increasing competition for food crops is essential. Yet, many unknowns relate to livestock grazing, in particular grazing intensity, an essential variable to assess the sustainability of livestock systems. Here, we explore ecological limits to grazing intensity (GI; i.e. the fraction of net primary production consumed by grazing animals) by analysing the role of seasonality in natural grasslands. We estimate seasonal limitations to GI by combining monthly net primary production data and a map of global livestock distribution with assumptions on the length of nonfavourable periods that can be bridged by livestock (e.g. by browsing dead standing biomass, storage systems or biomass conservation). This allows us to derive a seasonality-limited potential GI, which we compare with the GI prevailing in 2000. We find that GI in 2000 lies below its potential on 39% of the total global natural grasslands, which has a potential for increasing biomass extraction of up to 181 MtC/yr. In contrast, on 61% of the area GI exceeds the potential, made possible by management. Mobilizing this potential could increase milk production by 5%, meat production by 4% or contribute to free up to 2.8 Mio km² of grassland area at the global scale if the numerous socio-ecological constraints can be overcome. We discuss socio-ecological trade-offs, which may reduce the estimated potential considerably and require the establishment of sound monitoring systems and an improved understanding of livestock system's role in the Earth system. © 2017 John Wiley & Sons Ltd.

  18. Grazing livestock are exposed to terrestrial cyanobacteria

    OpenAIRE

    McGorum , Bruce C; Pirie , R Scott; Glendinning , Laura; McLachlan , Gerry; Metcalf , James S; Banack , Sandra A; Cox , Paul A; Codd , Geoffrey A

    2015-01-01

    While toxins from aquatic cyanobacteria are a well-recognised cause of disease in birds and animals, exposure of grazing livestock to terrestrial cyanobacteria has not been described. This study identified terrestrial cyanobacteria, predominantly Phormidium spp., in the biofilm of plants from most livestock fields investigated. Lower numbers of other cyanobacteria, microalgae and fungi were present on many plants. Cyanobacterial 16S rDNA, predominantly from Phormidium spp., was detected in al...

  19. Effects of cultivar and grazing initiation date on fall-grown oat for replacement dairy heifers.

    Science.gov (United States)

    Coblentz, W K; Brink, G E; Esser, N M; Cavadini, J S

    2015-09-01

    Fall-grown oat has shown promise for extending the grazing season in Wisconsin, but the optimum date for initiating grazing has not been evaluated. Our objectives for this project were (1) to assess the pasture productivity and nutritive value of 2 oat cultivars [Ogle and ForagePlus (OG and FP, respectively)] with late-September (EG) or mid-October (LG) grazing initiation dates; and (2) to evaluate growth performance by heifers grazing these oat forages compared with heifers reared in confinement (CON). A total of 160 gravid Holstein heifers (80 heifers/yr) were assigned to 10 research groups (8 heifers/group). Mean initial body weight was 509±40.5 kg in 2013 and 517±30.2 kg in 2014. Heifer groups were assigned to specific pastures arranged as a 2×2 factorial of oat cultivars and grazing initiation dates. Grazing heifer groups were allowed to strip-graze oat pastures for 6 h daily before returning to the barn, where they were offered a forage-based basal total mixed ration. Main effects of oat cultivar and sampling date interacted for forage characteristics in 2013, but not in 2014. During 2013, oat forage mass increased until early November before declining in response to freezing weather conditions, thereby exhibiting linear and quadratic effects of sampling date, regardless of oat cultivar. Similar trends over time were observed in 2014. For 2013, the maximum forage mass was 5,329 and 5,046 kg/ha for FP and OG, respectively, whereas the mean maximum forage mass for 2014 was 4,806 kg/ha. ForagePlus did not reach the boot stage of growth during either year of the trial; OG matured more rapidly, reaching the late-heading stage during 2013, but exhibited only minor maturity differences from FP in 2014. For 2013, average daily gain for CON did not differ from grazing heifer groups (overall mean=0.63 kg/d); however, average daily gain from FP was greater than OG (0.68 vs. 0.57 kg/d), and greater from EG compared with LG (0.82 vs. 0.43 kg/d). For 2013, advantages in

  20. Restoring fire as an ecological process in shortgrass prairie ecosystems: initial effects of prescribed burning during the dormant and growing seasons.

    Science.gov (United States)

    Brockway, Dale G; Gatewood, Richard G; Paris, Randi B

    2002-06-01

    Prior to Anglo-European settlement, fire was a major ecological process influencing the structure, composition and productivity of shortgrass prairie ecosystems on the Great Plains. However during the past 125 years, the frequency and extent of grassland fire has dramatically declined as a result of the systematic heavy grazing by large herds of domestic cattle and sheep which reduced the available levels of fine fuel and organized fire suppression efforts that succeeded in altering the natural fire regime. The greatly diminished role of recurrent fire in these ecosystems is thought to be responsible for ecologically adverse shifts in the composition, structure and diversity of these grasslands, leading specifically to the rise of ruderal species and invasion by less fire-tolerant species. The purpose of this study was to evaluate the ecological effects of fire season and frequency on the shortgrass prairie and to determine the means by which prescribed fire can best be restored in this ecosystem to provide the greatest benefit for numerous resource values. Plant cover, diversity, biomass and nutrient status, litter cover and soil chemistry were measured prior to and following fire treatments on a buffalograss-blue grama shortgrass prairie in northeastern New Mexico. Dormant-season fire was followed by increases in grass cover, forb cover, species richness and concentrations of foliar P, K, Ca, Mg and Mn. Growing-season fire produced declines in the cover of buffalograss, graminoids and forbs and increases in litter cover and levels of foliar P, K, Ca and Mn. Although no changes in soil chemistry were observed, both fire treatments caused decreases in herbaceous production, with standing biomass resulting from growing-season fire approximately 600 kg/ha and dormant-season fire approximately 1200 kg/ha, compared with controls approximately 1800 kg/ha. The initial findings of this long-term experiment suggest that dormant-season burning may be the preferable method

  1. COMPARISON OF THE POPULATIONS OF COMMON WOOD-NYMPH BUTTERFLIES IN BURNED PRAIRIE, UNBURNED PRAIRIE AND OLD FIELD GRASSES

    Energy Technology Data Exchange (ETDEWEB)

    Hahn, M.; Walton, R.

    2007-01-01

    Common wood-nymph butterfl ies are found throughout the United States and Canada. However, not much is known about how they overwinter or their preferences for particular grasses and habitats. In this study, the impact of prairie management plans on the abundance of the wood-nymph population was assessed, as well as the preference of these butterfl ies for areas with native or non-native grasses. The abundance of common wood-nymph butterfl ies was determined using Pollard walks; more common wood-nymph butterfl ies were found in the European grasses than were found in the burned and unburned prairie sites. The majority of the vegetation at each of the three sites was identifi ed and documented. Using a 1 X 3 ANOVA analysis, it was determined there were signifi cantly more butterfl ies in the European grasses than in the burned and unburned prairie sites (p < 0.0005). There was no signifi cant difference between the burned and unburned treatments of the prairie on the common wood-nymph population. A multiple variable linear regression model described the effect of temperature and wind speed on the number of observed common wood-nymph butterfl ies per hour (p = 0.026). These preliminary results need to be supplemented with future studies. Quadrat analysis of the vegetation from all three sites should be done to search for a correlation between common wood-nymph butterfl y abundance per hour and the specifi c types or quantity of vegetation at each site. The effect of vegetation height and density on the observer’s visual fi eld should also be assessed.

  2. Tuberculosis transmission in the Indigenous peoples of the Canadian prairies.

    Science.gov (United States)

    Patel, Smit; Paulsen, Catherine; Heffernan, Courtney; Saunders, Duncan; Sharma, Meenu; King, Malcolm; Hoeppner, Vernon; Orr, Pamela; Kunimoto, Dennis; Menzies, Dick; Christianson, Sara; Wolfe, Joyce; Boffa, Jody; McMullin, Kathleen; Lopez-Hille, Carmen; Senthilselvan, Ambikaipakan; Long, Richard

    2017-01-01

    The prairie provinces of Canada. To characterize tuberculosis (TB) transmission among the Indigenous and non-Indigenous Canadian-born peoples of the prairie provinces of Canada. A prospective epidemiologic study of consecutively diagnosed adult (age ≥ 14 years) Canadian-born culture-positive pulmonary TB cases on the prairies, hereafter termed "potential transmitters," and the transmission events generated by them. "Transmission events" included new positive tuberculin skin tests (TSTs), TST conversions, and secondary cases among contacts. In the years 2007 and 2008, 222 potential transmitters were diagnosed on the prairies. Of these, the vast majority (198; 89.2%) were Indigenous peoples who resided in either an Indigenous community (135; 68.2%) or a major metropolitan area (44; 22.2%). Over the 4.5-year period between July 1st, 2006 and December 31st 2010, 1085 transmission events occurred in connection with these potential transmitters. Most of these transmission events were attributable to potential transmitters who identified as Indigenous (94.5%). With a few notable exceptions most transmitters and their infected contacts resided in the same community type. In multivariate models positive smear status and a higher number of close contacts were associated with increased transmission; adjusted odds ratios (ORs) and 95% confidence intervals (CIs), 4.30 [1.88, 9.84] and 2.88 [1.31, 6.34], respectively. Among infected contacts, being Indigenous was associated with disease progression; OR and 95% CI, 3.59 [1.27, 10.14] and 6.89 [2.04, 23.25] depending upon Indigenous group, while being an infected casual contact was less likely than being a close contact to be associated with disease progression, 0.66 [0.44, 1.00]. In the prairie provinces of Canada and among Canadian-born persons, Indigenous peoples account for the vast majority of cases with the potential to transmit as well as the vast majority of infected contacts. Active case finding and preventative therapy

  3. Grazing disturbance increases transient but decreases persistent soil seed bank.

    Science.gov (United States)

    Ma, Miaojun; Walck, Jeffrey L; Ma, Zhen; Wang, Lipei; Du, Guozhen

    2018-04-30

    Very few studies have examined whether the impacts of grazing disturbance on soil seed banks occur directly or indirectly through aboveground vegetation and soil properties. The potential role of the seed bank in alpine wetland restoration is also unknown. We used SEM (structural equation modeling) to explore the direct effect of grazing disturbance on the seed bank and the indirect effect through aboveground vegetation and soil properties. We also studied the role of the seed bank on the restoration potential in wetlands with various grazing intensities: low (fenced, winter grazed only), medium (seasonally grazed), and high (whole-year grazed). For the seed bank, species richness and density per plot showed no difference among grazing intensities for each depth (0-5, 5-10, 10-15 cm) and for the whole depth (0-15 cm) in spring and summer. There was no direct effect of grazing disturbance on seed bank richness and density both in spring and summer, and also no indirect effect on the seed bank through its direct effect on vegetation richness and abundance. Grazing disturbance indirectly increased spring seed bank density but decreased summer seed bank density through its direct effect (negative correlation) on soil moisture and total nitrogen and its indirect effect on vegetation abundance. Species composition of the vegetation changed with grazing regime, but that of the seed bank did not. An increased trend of similarity between the seed bank and aboveground vegetation with increased grazing disturbance was found in the shallow depth and in the whole depth only in spring. Although there was almost no change in seed bank size with grazing intensities, grazing disturbance increased the quantity of transient seeds but decreased persistent seeds. Persistent seeds stored in the soil could play a crucial role in vegetation regeneration and in restoration of degraded wetland ecosystems. The seed bank should be an integral part of alpine wetland restoration programs.

  4. 77 FR 24975 - Endangered and Threatened Wildlife and Plants; Revised Recovery Plan for the Utah Prairie Dog

    Science.gov (United States)

    2012-04-26

    ...-FF06E00000] Endangered and Threatened Wildlife and Plants; Revised Recovery Plan for the Utah Prairie Dog... Utah prairie dog (Cynomys parvidens). This species is federally listed as threatened under the... recovery plan for the Utah prairie dog. The Service and other Federal agencies also will take these...

  5. 75 FR 57055 - Endangered and Threatened Wildlife and Plants; Draft Revised Recovery Plan for Utah Prairie Dog

    Science.gov (United States)

    2010-09-17

    ...] Endangered and Threatened Wildlife and Plants; Draft Revised Recovery Plan for Utah Prairie Dog AGENCY: Fish... recovery plan for the Utah prairie dog (Cynomys parvidens). This species is federally listed as threatened... and peer reviewers in an appendix to the approved recovery plan. The Utah prairie dog (Cynomys...

  6. 76 FR 31906 - Endangered and Threatened Wildlife and Plants; Revising the Special Rule for the Utah Prairie Dog

    Science.gov (United States)

    2011-06-02

    ... Special Rule for the Utah Prairie Dog AGENCY: Fish and Wildlife Service, Interior. ACTION: Proposed rule... prairie dog. We are proposing to revise the existing limits on take, and we also propose a new incidental... dogs see: http://www.fws.gov/mountain-prairie/species/mammals/UTprairiedog or http://ecos.fws.gov...

  7. 77 FR 46157 - Endangered and Threatened Wildlife and Plants; Revising the Special Rule for the Utah Prairie Dog

    Science.gov (United States)

    2012-08-02

    ... Utah Prairie Dog; Final Rule #0;#0;Federal Register / Vol. 77 , No. 149 / Thursday, August 2, 2012...-AW02 Endangered and Threatened Wildlife and Plants; Revising the Special Rule for the Utah Prairie Dog... special regulations for the conservation of the Utah prairie dog. We are revising our special regulations...

  8. 78 FR 26302 - Endangered and Threatened Wildlife and Plants; Listing the Lesser Prairie-Chicken as a Threatened...

    Science.gov (United States)

    2013-05-06

    ...; 4500030113] RIN 1018-AY21 Endangered and Threatened Wildlife and Plants; Listing the Lesser Prairie-Chicken... the lesser prairie-chicken (Tympanuchus pallidicinctus). In addition, we announce the reopening of the public comment period on the December 11, 2012, proposed rule to list the lesser prairie-chicken as a...

  9. 78 FR 75306 - Endangered and Threatened Wildlife and Plants; Listing the Lesser Prairie-Chicken as a Threatened...

    Science.gov (United States)

    2013-12-11

    ...; 4500030113] RIN 1018-AY21 Endangered and Threatened Wildlife and Plants; Listing the Lesser Prairie-Chicken... the conservation of the lesser prairie-chicken (Tympanuchus pallidicinctus). In addition, we announce... prairie-chicken as a threatened species under the Act. We also announce the availability of the final...

  10. Using Halogens (Cl, Br, F, I) and Stable Isotopes of Water (δ18O, δ2H) to Trace Hydrological and Biogeochemical Processes in Prairie Wetlands

    Science.gov (United States)

    Levy, Z. F.; Lu, Z.; Mills, C. T.; Goldhaber, M. B.; Rosenberry, D. O.; Mushet, D.; Siegel, D. I.; Fiorentino, A. J., II; Gade, M.; Spradlin, J.

    2014-12-01

    Prairie pothole wetlands are ubiquitous features of the Great Plains of North America, and important habitat for amphibians and migratory birds. The salinity of proximal wetlands varies highly due to groundwater-glacial till interactions, which influence wetland biota and associated ecosystem functions. Here we use halogens and stable isotopes of water to fingerprint hydrological and biogeochemical controls on salt cycling in a prairie wetland complex. We surveyed surface, well, and pore waters from a groundwater recharge wetland (T8) and more saline closed (P1) and open (P8) basin discharge wetlands in the Cottonwood Lake Study Area (ND) in August/October 2013 and May 2014. Halogen concentrations varied over a broad range throughout the study area (Cl = 2.2 to 170 mg/L, Br = 13 to 2000 μg/L, F = evaporation-enriched pond water (δ18O = -9.5 to -2.71 ‰) mixes with shallow groundwater in the top 0.6 m of fringing wetland soils and 1.2 m of the substrate in the center of P1. Our results suggest endogenous sources for Br and I within the prairie landscape that may be controlled by biological mechanisms or weathering of shale from glacial till.

  11. Carbon budgets for an irrigated intensively grazed dairy pasture and an unirrigated winter-grazed pasture

    Science.gov (United States)

    Hunt, John E.; Laubach, Johannes; Barthel, Matti; Fraser, Anitra; Phillips, Rebecca L.

    2016-05-01

    Intensification of pastoral agriculture is occurring rapidly across New Zealand, including increasing use of irrigation and fertiliser application in some regions. While this enables greater gross primary production (GPP) and livestock grazing intensity, the consequences for the net ecosystem carbon budget (NECB) of the pastures are poorly known. Here, we determined the NECB over one year for an irrigated, fertilised and rotationally grazed dairy pasture and a neighbouring unirrigated, unfertilised, winter-grazed pasture. Primary terms in the NECB calculation were: net ecosystem production (NEP), biomass carbon removed by grazing cows and carbon (C) input from their excreta. Annual NEP was measured using the eddy-covariance method. Carbon removal was estimated with plate-meter measurements calibrated against biomass collections, pre- and post-grazing. Excreta deposition was calculated from animal feed intake. The intensively managed pasture gained C (NECB = 103 ± 42 g C m-2 yr-1) but would have been subject to a non-significant C loss if cattle excreta had not been returned to the pasture. The unirrigated pasture was C-neutral (NECB = -13 ± 23 g C m-2 yr-1). While annual GPP of the former was almost twice that of the latter (2679 vs. 1372 g C m-2 yr-1), ecosystem respiration differed by only 68 % between the two pastures (2271 vs. 1352 g C m-2 yr-1). The ratio of GPP to the total annual water input of the irrigated pasture was 37 % greater than that of the unirrigated pasture, i.e. the former used the water input more efficiently than the latter to produce biomass. The NECB results agree qualitatively with those from many other eddy-covariance studies of grazed grasslands, but they seem to be at odds with long-term carbon-stock studies of other New Zealand pastures.

  12. Annual Fire, Mowing and Fertilization Effects on Two Cicada Species (Homoptera: Cicadidae) in Tallgrass Prairie

    Science.gov (United States)

    Mac A. Callaham; Matt R. Whiles; John M. Blair

    2002-01-01

    In tallgrass prairie, cicadas emerge annually, are abundant and their emergence can be an important flux of energy and nutrients. However, factors influencing the distribution and abundance of these cicadas are virtually unknown. We examined cicada emergence in plots from a long-term (13 y) experimental manipulation involving common tallgrass prairie management...

  13. Ecology of fire in shortgrass prairie of the southern Great Plains

    Science.gov (United States)

    Paulette L. Ford; Guy R. McPherson

    1996-01-01

    The ecology of fire in shortgrass prairie of the southern Great Plains includes a complex interaction between the shortgrass prairie ecosystem and its inhabitants, all inextricably linked to land-use patterns. The history of the relationship between man and fire has been filled with ambivalence and mistrust, along with an appreciation of the power of fire as a...

  14. 77 FR 75119 - Dakota Prairie Grasslands, North Dakota; Oil and Gas Development Supplemental Environmental...

    Science.gov (United States)

    2012-12-19

    ... DEPARTMENT OF AGRICULTURE Forest Service Dakota Prairie Grasslands, North Dakota; Oil and Gas... to prepare a supplemental environmental impact statement. SUMMARY: In June of 2003, the Dakota... Dakota Prairie Grasslands Land and Resource Management Plan, based on the 2001 Northern Great Plains...

  15. The role of prairie dogs as a keystone species: response to Stapp

    Science.gov (United States)

    B. Miller; R. Reading; J. Hoogland; T. Clark; G. Ceballos; R. List; S. Forrest; L. Hanebury; P. Manzano; J. Pacheco; D. Uresk

    2000-01-01

    Stapp (1998) recently argued that it was premature to characterize prairie dogs (Cynomys spp.) as keystone species. In particular, Stapp directed much of his criticism at a paper some of us wrote (Miller et al. 1994). He mistakenly interprets the main objective of our paper as providing evidence that prairie dogs are keystone species. Rather, the...

  16. Review of black-tailed prairie dog reintroduction strategies and site selection: Arizona reintroduction

    Science.gov (United States)

    Sarah L. Hale; John L. Koprowski; Holly Hicks

    2013-01-01

    The black-tailed prairie dog (Cynomys ludovicianus) was once widely distributed throughout the western United States; however, anthropogenic influences have reduced the species’ numbers to 2 percent of historical populations. Black-tailed prairie dogs are described as a keystone species in the grassland ecosystem, and provide many unique services, including burrows for...

  17. Black-tailed prairie dog (Cynomys ludovicianus) response to seasonality and frequency of fire

    Science.gov (United States)

    Felicia D. Archuleta

    2014-01-01

    Fragmentation of the landscape, habitat loss, and fire suppression, all a result of European settlement and activities, have precipitated both the decline of Black-tailed prairie dog (Cynomys ludovicianus) populations and the occurrence of fire throughout the Great Plains, including the Shortgrass steppe of northeastern New Mexico. The presence of Black-tailed prairie...

  18. Prairie dog decline reduces the supply of ecosystem services and leads to desertification of semiarid grasslands.

    Directory of Open Access Journals (Sweden)

    Lourdes Martínez-Estévez

    Full Text Available Anthropogenic impacts on North American grasslands, a highly endangered ecosystem, have led to declines of prairie dogs, a keystone species, over 98% of their historical range. While impacts of this loss on maintenance of grassland biodiversity have been widely documented, much less is known about the consequences on the supply of ecosystem services. Here we assessed the effect of prairie dogs in the supply of five ecosystem services by comparing grasslands currently occupied by prairie dogs, grasslands devoid of prairie dogs, and areas that used to be occupied by prairie dogs that are currently dominated by mesquite scrub. Groundwater recharge, regulation of soil erosion, regulation of soil productive potential, soil carbon storage and forage availability were consistently quantitatively or qualitatively higher in prairie dog grasslands relative to grasslands or mesquite scrub. Our findings indicate a severe loss of ecosystem services associated to the absence of prairie dogs. These findings suggest that contrary to a much publicize perception, especially in the US, prairie dogs are fundamental in maintaining grasslands and their decline have strong negative impacts in human well - being through the loss of ecosystem services.

  19. Plant composition in oak savanna and woodland restoration at Prairie Fork Conservation Area in Missouri

    Science.gov (United States)

    Nadia E. Navarrete-Tindall; J.W. Van Sambeek; Jamie Coe; Warren Taylor

    2007-01-01

    The wooded areas of the Prairie Fork Conservation Area in central Missouri are typical of the oak/hickory forest/prairie transition zone that will require active management to restore pre-settlement, grass dominated savannas and open woodlands to improve habitat for wildlife. We initiated a management program to restore savannas and woodlands by reducing the midstory (...

  20. Demography of black-tailed prairie dog populations reoccupying sites treated with rodenticide

    Science.gov (United States)

    R. P. Cincotta; Daniel W. Uresk; R. M. Hansen

    1987-01-01

    A rodenticide, zinc phosphide, was applied to remove black-tailed prairie dogs (Cynomys ludovicianus) from 6 haofa prairie dog colony in southwestern South Dakota. Another adjacent 6 ha was left untreated. The removal experiment was repeated two consecutive years. Contingency table analysis showed that the resultant population was not homogeneous;...

  1. Prairie chicken populations of the Sheyenne Delta in North Dakota, 1961-1987

    Science.gov (United States)

    Jerry D. Kobriger; David P. Vollink; Michael E. Mcneill; Kenneth F. Higgins

    1988-01-01

    Prairie chickens (Tympanuchus cupido pinnatus) were first censused on the Sheyenne Grasslands in 1961. The population was extremely low in the 1960's, gradually increased in the 1970's, and reached a peak of 410 in 1980. Sufficient evidence exists to link the increase in numbers of prairie chickens on the grasslands from 1961 through 1987...

  2. Effect of mid-summer haying on growth and reproduction in prairie forbs

    Science.gov (United States)

    Becky Begay; Helen M. Alexander; Erin Questad

    2011-01-01

    Mid-summer haying is a common management practice for prairies; plant species could differ in the effect of haying on subsequent growth and reproduction. We examined the effect of haying on prairie species by performing a clipping experiment. For each of seven species, sixteen plants were chosen and half were randomly assigned to a clipping treatment and half to a...

  3. Physiologic Reference Ranges for Captive Black-Tailed Prairie Dogs (Cynomys ludovicianus)

    Science.gov (United States)

    Keckler, M Shannon; Gallardo-Romero, Nadia F; Langham, Gregory L; Damon, Inger K; Karem, Kevin L; Carroll, Darin S

    2010-01-01

    The black-tailed prairie dog (Cynomys ludovicianus) is a member of the order Rodentia and the family Sciuridae. Ecologically, prairie dogs are a keystone species in prairie ecology. This species is used as an animal model for human gallbladder disease and diseases caused by infection with Clostridium difficile, Yersinia pestis, Francisella tularensis, and most recently, Orthopoxvirus. Despite increasing numbers of prairie dogs used in research and kept as pets, few data are available on their baseline physiology in animal facility housing conditions. To establish baseline physiologic reference ranges, we designed a study using 18 wild-caught black-tailed prairie dogs. Telemetry data were analyzed to establish circadian rhythms for activity and temperature. In addition, hematologic and serum chemistry analyses were performed. Baseline measurements were used to establish the mean for each animal, which then were compiled and analyzed to determine the reference ranges. Here we present physiologic data on serum chemistry and hematology profiles, as well as weight, core body temperature, and daily activity patterns for black-tailed prairie dogs. These results reflect the use of multiple measurements from species- and age-matched prairie dogs and likely will be useful to ecologists, scientists interested in using this animal model in research, and veterinarians caring for pet prairie dogs. PMID:20587156

  4. A novel approach for assessing density and range-wide abundance of prairie dogs

    Science.gov (United States)

    Aaron N. Facka; Paulette L. Ford; Gary W. Roemer

    2008-01-01

    Habitat loss, introduced disease, and government-sponsored eradication programs have caused population declines in all 5 species of prairie dogs. Black-tailed prairie dogs (Cynomys ludovicianus) currently occupy only about 2% of an extensive geographic range (160 million hectares) and were recently considered for listing under the United States...

  5. Using stable isotopes to understand hydrochemical processes in and around a Prairie Pothole wetland in the Northern Great Plains, USA

    International Nuclear Information System (INIS)

    Mills, Christopher T.; Goldhaber, Martin B.; Stricker, Craig A.; Holloway, JoAnn M.; Morrison, Jean M.; Ellefsen, Karl J.; Rosenberry, Donald O.; Thurston, Roland S.

    2011-01-01

    Highlights: → A stable isotope study of the hydrochemistry of a Prairie Pothole wetland system. → δ 18 O H2O and δ 2 H H2O values show salt concentration by transpiration at wetland edge. → A range of δ 34 S SO4 values indicate SO 4 source and reduction processes. → Isotopic mixing lines show interaction of surface and groundwater at wetland edge. - Abstract: Millions of internally drained wetland systems in the Prairie Potholes region of the northern Great Plains (USA and Canada) provide indispensable habitat for waterfowl and a host of other ecosystem services. The hydrochemistry of these systems is complex and a crucial control on wetland function, flora and fauna. Wetland waters can have high concentrations of SO 4 2- due to the oxidation of large amounts of pyrite in glacial till that is in part derived from the Pierre shale. Water chemistry including δ 18 O H2O , δ 2 H H2O , and δ 34 S SO4 values, was determined for groundwater, soil pore water, and wetland surface water in and around a discharge wetland in North Dakota. The isotopic data for the first time trace the interaction of processes that affect wetland chemistry, including open water evaporation, plant transpiration, and microbial SO 4 reduction.

  6. Citizen knowledge and perception of black-tailed prairie dog management: Report to respondents

    Science.gov (United States)

    Sexton, Natalie R.; Brinson, Ayeisha; Ponds, Phadrea D.; Cline, Kurt; Lamb, Berton L.

    2001-01-01

    What do citizens know about black-tailed prairie dogs, and where do they get their information? When management decisions need to be made regarding an animal such as the black-tailed prairie dog, an understanding of the species and its relationship to humans is necessary. This includes knowing the biology of the animal, where it lives, and how it interacts with other animals. But it is equally important for those making decisions about the species to understand citizens’ knowledge and perceptions so managers can effectively communicate with the public and help the public participate in planning and decision making activities. Unfortunately, what is known about public knowledge, perception, and preferences concerning prairie dog management is limited to data from only a few areas. This study attempts to answer the question: What do people in the short-grass prairie region of the United States know and think about black-tailed prairie dogs?

  7. Precipitation, Climate Change, and Parasitism of Prairie Dogs by Fleas that Transmit Plague.

    Science.gov (United States)

    Eads, David A; Hoogland, John L

    2017-08-01

    Fleas (Insecta: Siphonaptera) are hematophagous ectoparasites that can reduce the fitness of vertebrate hosts. Laboratory populations of fleas decline under dry conditions, implying that populations of fleas will also decline when precipitation is scarce under natural conditions. If precipitation and hence vegetative production are reduced, however, then herbivorous hosts might suffer declines in body condition and have weakened defenses against fleas, so that fleas will increase in abundance. We tested these competing hypotheses using information from 23 yr of research on 3 species of colonial prairie dogs in the western United States: Gunnison's prairie dog (Cynomys gunnisoni, 1989-1994), Utah prairie dog (Cynomys parvidens, 1996-2005), and white-tailed prairie dog (Cynomys leucurus, 2006-2012). For all 3 species, flea-counts per individual varied inversely with the number of days in the prior growing season with >10 mm of precipitation, an index of the number of precipitation events that might have caused a substantial, prolonged increase in soil moisture and vegetative production. Flea-counts per Utah prairie dog also varied inversely with cumulative precipitation of the prior growing season. Furthermore, flea-counts per Gunnison's and white-tailed prairie dog varied inversely with cumulative precipitation of the just-completed January and February. These results complement research on black-tailed prairie dog (Cynomys ludovicianus) and might have important ramifications for plague, a bacterial disease transmitted by fleas that devastates populations of prairie dogs. In particular, our results might help to explain why, at some colonies, epizootics of plague, which can kill >95% of prairie dogs, are more likely to occur during or shortly after periods of reduced precipitation. Climate change is projected to increase the frequency of droughts in the grasslands of western North America. If so, then climate change might affect the occurrence of plague epizootics

  8. Developmental instability and fitness in Periploca laevigata experiencing grazing disturbance

    Science.gov (United States)

    Alados, C.L.; Giner, M.L.; Dehesa, L.; Escos, J.; Barroso, F.; Emlen, J.M.; Freeman, D.C.

    2002-01-01

    We investigated the sensitivity of developmental instability measurements (leaf fluctuating asymmetry, floral radial asymmetry, and shoot translational asymmetry) to a long‐standing natural stress (grazing) in a palatable tannin‐producing shrub (Periploca laevigata Aiton). We also assessed the relationship between these measures of developmental instability and fitness components (growth and floral production). Developmental instability, measured by translational asymmetry, was the most accurate estimator of a plant’s condition and, consequently, environmental stress. Plants with less translational asymmetry grew more and produced more flowers. Plants from the medium‐grazed population were developmentally more stable, as estimated by translational and floral asymmetry, than either more heavily or more lightly grazed populations. Leaf fluctuating asymmetry was positively correlated with tannin concentration. The pattern of internode growth also responded to grazing impact. Plants under medium to heavy grazing pressure accelerated early growth and consequently escaped herbivory later in the season, i.e., at the beginning of the spring, when grazing activity was concentrated in herbaceous plants. Periploca laevigata accelerated growth and finished growing sooner than in the other grazing treatment. Thus, its annual growth was more mature and less palatable later in the season when grazers typically concentrate on shrubs. The reduction of developmental instability under medium grazing is interpreted as a direct effect of grazing and not as the release from competition.

  9. Ecological Effects of Grazing in the Northern Tianshan Mountains

    Directory of Open Access Journals (Sweden)

    Xiaotao Huang

    2017-11-01

    Full Text Available Identifying the effects of grazing is critical for the conservation, protection and sustainable use of arid grassland ecosystems. However, research regarding the ecological effects of grazing along mountainous elevation gradients is limited in arid areas, particularly at the regional scale. Using the Biome-BGC grazing model, we explored the effects of grazing on grassland net primary productivity (NPP, evapotranspiration (ET and water use efficiency (WUE from 1979 to 2012 along an elevation gradient in the northern Tianshan Mountains. The NPP, ET and WUE values were generally lower under the grazing scenario than under the ungrazed scenario; the differences between the grazing and ungrazed scenarios showed increasing trends over time; and distinct spatial heterogeneity in these differences was observed. Distinct decreases in NPP and WUE under the grazing scenario mainly occurred in regions with high livestock consumption. The decrease in ET was greater in mountainous areas with high grazing intensity due to decreased transpiration and increased surface runoff. This study contributes to a better understanding of the ecological effects of grazing along an elevation gradient in the northern Tianshan Mountains and provides data to support the scientific management of grassland ecosystems.

  10. Livestock grazing and the desert tortoise in the Mojave Desert

    Science.gov (United States)

    Oldemeyer, John L.

    1994-01-01

    A large part of the Mojave Desert is not in pristine condition, and some current conditions can be related to past grazing-management practices. No information could be found on densities of the desert tortoise (Gopherus agassizii) or on vegetative conditions of areas that had not been grazed to allow managers a comparison of range conditions with data on tortoises. Experimental information to assess the effect of livestock grazing on tortoises is lacking, and researchers have not yet examined whether the forage that remains after grazing is sufficient to meet the nutritional needs of desert tortoises.

  11. Iodine-129 in thyroids of grazing animals

    International Nuclear Information System (INIS)

    Ballad, R.V.; Holman, D.W.; Hennecke, E.W.; Johnson, J.E.; Manuel, O.K.; Nicholson, L.M.

    1976-01-01

    A combination of neutron activation and mass spectrometry has been used to determine the concentrations of fissiogenic 129 I and stable 127 I in thyroids of grazing animals and in mineral iodine. The 129 I/ 127 I ratios are lowest in mineral iodine and in a given area lower in cow thyroids than in deer thyroids. Near saturation levels of mineral iodine in commercial feeds and salt licks may account for differences in the 129 I levels of cows and deer. Values of the 129 I/ 127 I ratio in deer appear to vary inversely with the iodine concentration of the thyroid. (author)

  12. Milk production, grazing behavior and nutritional status of dairy cows grazing two herbage allowances during winter

    Directory of Open Access Journals (Sweden)

    Miguel Ruiz-Albarran

    2016-03-01

    Full Text Available Winter grazing provides a useful means for increasing the proportion of grazed herbage in the annual diet of dairy cows. This season is characterized by low herbage growth rate, low herbage allowance, and low herbage intake and hence greater needs for supplements to supply the requirements of lactating dairy cows. The aim of this study was to determine the influence of herbage allowance (HA offered to autumn calving dairy cows grazing winter herbage on milk production, nutritional status, and grazing behavior. The study took 63 d using 32 multiparous Holstein-Friesian dairy cows. Prior to experimental treatment, milk production averaged 20.2 ± 1.7 kg d-1, body weight was 503 ± 19 kg, and days in milking were 103 ± 6. Experimental animals were randomly assigned to two treatments according to HA offered above ground level: low (17 kg DM cow-1 d-1 vs. high HA (25 kg DM cow¹ d¹. All cows were supplemented with grass silage supplying daily 6.25 and 4.6 kg DM of concentrate (concentrate commercial plus high corn moisture. Decreasing HA influenced positively milk production (+25%, milk protein (+20 kg, and milk fat (+17 kg per hectare; however no effects on milk production per cow or energy metabolic status were observed in the cows. In conclusion, a low HA showed to be the most significant influencing factor on milk and milk solids production per hectare in dairy cows grazing restricted winter and supplemented with grass silage and concentrate; but no effect on the milk production per cow was found.

  13. Modelling nitrous oxide emissions from grazed grassland systems

    International Nuclear Information System (INIS)

    Wang Junye; Cardenas, Laura M.; Misselbrook, Tom H.; Cuttle, Steve; Thorman, Rachel E.; Li Changsheng

    2012-01-01

    Grazed grassland systems are an important component of the global carbon cycle and also influence global climate change through their emissions of nitrous oxide and methane. However, there are huge uncertainties and challenges in the development and parameterisation of process-based models for grazed grassland systems because of the wide diversity of vegetation and impacts of grazing animals. A process-based biogeochemistry model, DeNitrification-DeComposition (DNDC), has been modified to describe N 2 O emissions for the UK from regional conditions. This paper reports a new development of UK-DNDC in which the animal grazing practices were modified to track their contributions to the soil nitrogen (N) biogeochemistry. The new version of UK-DNDC was tested against datasets of N 2 O fluxes measured at three contrasting field sites. The results showed that the responses of the model to changes in grazing parameters were generally in agreement with observations, showing that N 2 O emissions increased as the grazing intensity increased. - Highlights: ► Parameterisation of grazing system using grazing intensity. ► Modification of UK D NDC for the UK soil and weather conditions. ► Validation of the UK D NDC against measured data of N 2 O emissions in three UK sites. ► Estimating influence of animal grazing practises on N 2 O emissions. - Grazing system was parameterised using grazing intensity and UK-DNDC model was modified and validated against measured data of N 2 O emissions in three UK sites.

  14. Season and application rates affect vaccine bait consumption by prairie dogs in Colorado and Utah, USA

    Science.gov (United States)

    Tripp, Daniel W.; Rocke, Tonie E.; Streich, Sean P.; Brown, Nathanael L.; Fernandez, Julia Rodriguez-Ramos; Miller, Michael W.

    2014-01-01

    Plague, a zoonotic disease caused by the bacterium Yersinia pestis, causes high rates of mortality in prairie dogs (Cynomys spp.). An oral vaccine against plague has been developed for prairie dogs along with a palatable bait to deliver vaccine and a biomarker to track bait consumption. We conducted field trials between September 2009 and September 2012 to develop recommendations for bait distribution to deliver plague vaccine to prairie dogs. The objectives were to evaluate the use of the biomarker, rhodamine B, in field settings to compare bait distribution strategies, to compare uptake of baits distributed at different densities, to assess seasonal effects on bait uptake, and to measure bait uptake by nontarget small mammal species. Rhodamine B effectively marked prairie dogs' whiskers during these field trials. To compare bait distribution strategies, we applied baits around active burrows or along transects at densities of 32, 65, and 130 baits/ha. Distributing baits at active burrows or by transect did not affect uptake by prairie dogs. Distributing baits at rates of ≥65/ha (or ≥1 bait/active burrow) produced optimal uptake, and bait uptake by prairie dogs in the autumn was superior to uptake in the spring. Six other species of small mammals consumed baits during these trials. All four species of tested prairie dogs readily consumed the baits, demonstrating that vaccine uptake will not be an obstacle to plague control via oral vaccination.

  15. Factors influencing uptake of sylvatic plague vaccine baits by prairie dogs

    Science.gov (United States)

    Abbott, Rachel C.; Russell, Robin E.; Richgels, Katherine; Tripp, Daniel W.; Matchett, Marc R.; Biggins, Dean E.; Rocke, Tonie E.

    2017-01-01

    Sylvatic plague vaccine (SPV) is a virally vectored bait-delivered vaccine expressing Yersinia pestis antigens that can protect prairie dogs (Cynomys spp.) from plague and has potential utility as a management tool. In a large-scale 3-year field trial, SPV-laden baits containing the biomarker rhodamine B (used to determine bait consumption) were distributed annually at a rate of approximately 100–125 baits/hectare along transects at 58 plots encompassing the geographic ranges of four species of prairie dogs. We assessed site- and individual-level factors related to bait uptake in prairie dogs to determine which were associated with bait uptake rates. Overall bait uptake for 7820 prairie dogs sampled was 70% (95% C.I. 69.9–72.0). Factors influencing bait uptake rates by prairie dogs varied by species, however, in general, heavier animals had greater bait uptake rates. Vegetation quality and day of baiting influenced this relationship for black-tailed, Gunnison’s, and Utah prairie dogs. For these species, baiting later in the season, when normalized difference vegetation indices (a measure of green vegetation density) are lower, improves bait uptake by smaller animals. Consideration of these factors can aid in the development of species-specific SPV baiting strategies that maximize bait uptake and subsequent immunization of prairie dogs against plague.

  16. Dairy farmers using mob grazing in Pennsylvania and New York

    Science.gov (United States)

    Proponents of ultra-high stocking density grazing emphasize increased forage use efficiency and soil improvement by grazing mature forage with stocking densities up to 500,000 lb per acre of beef cattle on small paddocks with rest periods up to 180 days. However, it is unclear if this management tec...

  17. Day and night grazing by cattle in the Sahel

    NARCIS (Netherlands)

    Ayantunde, A.A.; Fernandez-Rivera, S.; Hiernaux, P.H.; Keulen, van H.; Udo, H.M.J.

    2002-01-01

    The influence of night grazing on feeding behavior, nutrition and performance of cattle was studied. Twenty-four steers weighing 367 kg (SD = 76) grazed either from 0900 to 1900 (day grazers), 2100 to 0700 (night grazers) or 0900 to 1900 and 2400 to 0400 (day-and-night grazers) during 13 weeks. Four

  18. Resilience of soils and vegetation subjected to different grazing ...

    African Journals Online (AJOL)

    The resilience of rangeland soils and vegetation to different levels of grazing is still poorly understood. A study was conducted to determine the recovery of a rangeland grazed at different intensities and allowed a two-year rest period. The following treatments were applied to 0.5 hectare plots: 0, 4, 8 and 16 heifers per ...

  19. Soil contamination of plant surfaces from grazing and rainfall interactions

    International Nuclear Information System (INIS)

    Hinton, T.G.; Stoll, J.M.; Tobler, L.

    1995-01-01

    Contaminants often attach to soil particles, and their subsequent environmental transport is largely determined by processes that govern soil movement. We examined the influence of grazing intensity on soil contamination of pastures. Four different grazing densities of sheep were tested against an ungrazed control plot. Scandium concentrations were determined by neutron activation analysis and was used as a tracer of soil adhesion on vegetation. Soil loadings ( g soil kg -1 dry plant) increased 60% when grazing intensity was increased by a factor of four (p 0.003). Rain and wind removed soil from vegetation in the ungrazed control plots, but when grazing sheep were present, an increase in rain from 0.3 to 9.7 mm caused a 130% increase in soil contamination. Multiple regression was used to develop an equation that predicts soil loadings as a function of grazing density, rainfall and wind speed (p = 0.0001, r 2 = 0.78). The model predicts that if grazing management were to be used as a tool to reduce contaminant intake from inadvertent consumption of resuspended soil by grazing animals, grazing densities would have to be reduced 2.5 times to reduce soil loadings by 50%. (author)

  20. White clover regenerative ability under N fertilizing and grazing

    Directory of Open Access Journals (Sweden)

    Josip Leto

    2008-12-01

    Full Text Available Recently, ecological and economic factors in milk and meat production stimulate use of legumes and grass-legumes mixtures, with zero or minimum mineral N as alternative to grass monoculture with high rate of mineral N. Research objective was to examine the effect of N application (0-N0 and 150 kg ha-1 year-1-N150 and rotational grazing by cattle (C and sheep (S on white clover: growing points number, stolon lenght, stolon dry weight, dry matter yield and clover contribution to total annual herbage production. N150 significantly reduced the growing points number, stolon length and stolon dry weight for more than 70 % compared to N0. Grazing treatment affected stolon population density only in interaction with N application because of N150 significantly reduced white clover population density only in sheep grazing. S-treatment had higher clover DM yield (0.21 t ha-1 than C-treatment (0.13 t ha-1. N0 had higher clover DM yield (0.25 t ha-1 than N150 (0.09 t ha-1. However, the interaction grazing management x N rate was significant for clover DM yield and clover contribution to total DM yield. N150 reduced both parameters for 80 % only in sheep grazing while difference in DM yield and clover contribution to total DM yield between grazing treatment was recorded only in N0 Sheep grazing increased DM yield for 150 % and clover contribution for 99 % compared to cattle grazing.

  1. Grass species selection patterns on rotationally-grazed Dohne ...

    African Journals Online (AJOL)

    Herbaceous species preference was studied during autumn and winter periods of occupation, on rotationally-grazed Dohne Sourveld, at four different stocking rates. Reports on species selection by cattle and sheep grazing together. Illustrates with graphsLanguage: English. Keywords: Grass species; Herbage availibility; ...

  2. Transformation of a savanna grassland by drought and grazing | O ...

    African Journals Online (AJOL)

    The relative effects of drought and heavy grazing on the floristic composition, population size and and structure, and basal cover of an African savanna grassland were differentiated by comparing changes over eight years over eight years, which included a severe drought year, across a gradient of grazing history. Drought ...

  3. The evaluation of four Eragrostis curvula ecotypes with grazing sheep.

    African Journals Online (AJOL)

    There were no significant differences in the dry matter production and chemical composition of the clipped samples of the ecotypes. Keywords: afrikaans; chemical composition; dry matter production; ecotypes; eragrostis curvula; grazing; live mass; live mass gains; open rotational grazing system; production; sheep; south ...

  4. Review: Behavior and daily grazing patterns of cattle

    NARCIS (Netherlands)

    Gregorini, P.; Tamminga, S.; Gunther, S.A.

    2006-01-01

    Grazing ruminants consume their food in discrete grazing events. The frequency and distribution of these events depend on the current physiological state of the animal and its environment. Within a small spatio-temporal scale, foraging decisions such as when to begin, which frequency, and how to

  5. Environmental Assessment of Beale AFB Grazing Lease Program

    Science.gov (United States)

    2012-12-01

    Beale AFB will use livestock (cattle, sheep and goats ) on its properties throughout the year as needed for the control of noxious weeds, reduction...initiating a wildfire. California Farm Bureau Federation policy recognizes that grazing is the most practical and environmentally acceptable way to...Site Monitoring Well Installation and Annual Targeted Goat Grazing Project, Placer County, California. 21 September 2011.  

  6. Possibilities and constraints for grazing in high output dairy systems

    NARCIS (Netherlands)

    Hennessy, D.; Delaby, L.; Pol, van den A.; Shalloo, L.

    2015-01-01

    In temperate and oceanic regions, grazed grass is the lowest cost feed available for milk production. In other regions, grazed grass is less important but can contribute to the diet of livestock. Within high output systems the interaction between the animal and sward is challenging for a host of

  7. The grazing index method of range condition assessment | du Toit ...

    African Journals Online (AJOL)

    Owing to the difficulty of examining succession theory in the Karoo, it is suggested the ecological index method (EIM), be replaced by the grazing index method (GIM), through the introduction of grazing index values (GIV) for Karoo plant species. The GIM may provide more acceptable range condition scores and more ...

  8. Forage selection and performance of sheep grazing dry annual range.

    NARCIS (Netherlands)

    Ridder, de N.; Benjamin, R.W.; Keulen, van H.

    1986-01-01

    During 114 days of grazing, sheep grazing a dry annual pasture in Israel selected the fine fraction available with a higher nutritive value. As this fraction became depleted and feed quality dropped, organic matter intake dropped from 1.73 to 0.75 kg/sheep/d. Sheep lost weight, body condition and

  9. Livestock Grazing as a Driver of Vernal Pool Ecohydrology

    Science.gov (United States)

    Michaels, J.; McCarten, N. F.

    2017-12-01

    Vernal pools are seasonal wetlands that host rare plant communities of high conservation priority. Plant community composition is largely driven by pool hydroperiod. A previous study found that vernal pools grazed by livestock had longer hydroperiods compared with pools excluded from grazing for 10 years, and suggests that livestock grazing can be used to protect plant diversity. It is important to assess whether observed differences are due to the grazing or due to water balance variables including upland discharge into or out of the pools since no a priori measurements were made of the hydrology prior to grazing. To address this question, in 2016 we compared 15 pools that have been grazed continuously and 15 pools that have been fenced off for over 40 years at a site in Sacramento County. We paired pools based on abiotic characteristics (size, shape, slope, soil type) to minimize natural variation. We sampled vegetation and water depth using Solinst level loggers. We found that plant diversity and average hydroperiod was significantly higher in the grazed pools. We are currently measuring groundwater connectivity and upland inputs in order to compare the relative strength of livestock grazing as a driver of hydroperiod to these other drivers.

  10. Effect of mowing and grazing on ramet emergence of Leymus ...

    African Journals Online (AJOL)

    user

    2011-03-21

    Mar 21, 2011 ... experiment was conducted in the spring of 2004 to investigate the effects on the surface soil temperature caused by mowing, grazing and grazing exclusion, and the influence of these factors on the ramets emergence characteristics. The primary effect of the treatments was significant changes in.

  11. Vegetation patterns and nutrients in relation to grazing pressure and ...

    African Journals Online (AJOL)

    A major challenge confronting managers of extensive grazing systems is uneven use of erbaceous forage plants by livestock. The concentration of grazing in preferred areas or around foci points (e.g. water points) eventually results in adverse impacts in soil nutrients, vegetation structure, production and composition.

  12. Grasses grazed by springbok and sheep | R. | African Journal of ...

    African Journals Online (AJOL)

    Grazing habits were determined by analysis of rumina from slaughtered springbok and sheep where springbok grazed together with Merino sheep in False Upper Karoo and together with Dorper sheep in Kalahari Thornveld. Results show that in both veld types, grass constituted about 39 percent of the dry mass intake of ...

  13. Spatial variation in keystone effects: Small mammal diversity associated with black-tailed prairie dog colonies

    Science.gov (United States)

    Cully, J.F.; Collinge, S.K.; Van Nimwegen, R. E.; Ray, C.; Johnson, W.C.; Thiagarajan, Bala; Conlin, D.B.; Holmes, B.E.

    2010-01-01

    Species with extensive geographic ranges may interact with different species assemblages at distant locations, with the result that the nature of the interactions may vary spatially. Black-tailed prairie dogs Cynomys ludovicianus occur from Canada to Mexico in grasslands of the western Great Plains of North America. Black-tailed prairie dogs alter vegetation and dig extensive burrow systems that alter grassland habitats for plants and other animal species. These alterations of habitat justify the descriptor " ecological engineer," and the resulting changes in species composition have earned them status as a keystone species. We examined the impact of black-tailed prairie dogs on small mammal assemblages by trapping at on- and off-colony locations at eight study areas across the species' geographic range. We posed 2 nested hypotheses: 1) prairie dogs function as a keystone species for other rodent species; and 2) the keystone role varies spatially. Assuming that it does, we asked what are the sources of the variation? Black-tailed prairie dogs consistently functioned as a keystone species in that there were strong statistically significant differences in community composition on versus off prairie dog colonies across the species range in prairie grassland. Small mammal species composition varied along both latitudinal and longitudinal gradients, and species richness varied from 4 to 11. Assemblages closer together were more similar; such correlations approximately doubled when including only on- or off-colony grids. Black-tailed prairie dogs had a significant effect on associated rodent assemblages that varied regionally, dependent upon the composition of the local rodent species pool. Over the range of the black-tailed prairie dog, on-colony rodent richness and evenness were less variable, and species composition was more consistent than off-colony assemblages. ?? 2010 The Authors.

  14. Lesser prairie-chicken avoidance of trees in a grassland landscape

    Science.gov (United States)

    Lautenbach, Joseph M.; Plumb, Reid T.; Robinson, Samantha G.; Hagen, Christian A.; Haukos, David A.; Pitman, James C.

    2016-01-01

    Grasslands are among the most imperiled ecosystems in North America. Reasons that grasslands are threatened include conversion to row-crop agriculture, fragmentation, and changes in fire regimes. The reduction of fire processes in remaining prairies has resulted in tree encroachment and establishment in grasslands, further reducing grassland quantity and quality. Grassland birds have been experiencing precipitous population declines in recent decades, commensurate with landscape changes to grasslands. The lesser prairie-chicken (Tympanuchus pallidicinctus Ridgway) is a declining species of prairie grouse of conservation concern. We used second- and third-order habitat selection metrics to test if female lesser prairie-chickens avoid grasslands where trees were present. Our results indicated that female lesser prairie-chickens selected habitats avoiding the nearest trees by 283 m on average, nearly twice as far as would be expected at random. Lesser prairie-chickens were 40 times more likely to use habitats with tree densities of 0 trees ∙ ha− 1 than habitats with 5 trees ∙ ha− 1. Probability of use indicated that lesser prairie-chickens were 19 times more likely to use habitats 1000 m from the nearest tree when compared with using habitats 0 m from the nearest tree. Nest survival was not affected at densities 2 trees ∙ ha− 1. Avoidance of trees could be due to perceived increased predation risk, reduced habitat quality, or a combination of these potentially confounding factors. Preventing further establishment and expansion of trees in landscapes occupied by lesser prairie-chickens could contribute to the continued persistence of the species. Additionally, restoring grasslands through tree removal may facilitate conservation efforts for grassland species such as the lesser prairie-chicken by improving habitat quality and promoting expansion of occupied range.

  15. Repeated burning of eastern tallgrass prairie increases richness and diversity, stabilizing late successional vegetation.

    Science.gov (United States)

    Bowles, Marlin L; Jones, Michael D

    2013-03-01

    Understanding temporal effects of fire frequency on plant species diversity and vegetation structure is critical for managing tallgrass prairie (TGP), which occupies a mid-continental longitudinal precipitation and productivity gradient. Eastern TGP has contributed little information toward understanding whether vegetation-fire interactions are uniform or change across this biome. We resampled 34 fire-managed mid- and late-successional ungrazed TGP remnants occurring across a dry to wet-mesic moisture gradient in the Chicago region of Illinois, USA. We compared hypotheses that burning acts either as a stabilizing force or causes change in diversity and structure, depending upon fire frequency and successional stage. Based on western TGP, we expected a unimodal species richness distribution across a cover-productivity gradient, variable functional group responses to fire frequency, and a negative relationship between fire frequency and species richness. Species diversity was unimodal across the cover gradient and was more strongly humpbacked in stands with greater fire frequency. In support of a stabilizing hypothesis, temporal similarity of late-successional vegetation had a logarithmic relationship with increasing fire frequency, while richness and evenness remained stable. Temporal similarity within mid-successional stands was not correlated with fire frequency, while richness increased and evenness decreased over time. Functional group responses to fire frequency were variable. Summer forb richness increased under high fire frequency, while C4 grasses, spring forbs, and nitrogen-fixing species decreased with fire exclusion. On mesic and wet-mesic sites, vegetation structure measured by the ratio of woody to graminoid species was negatively correlated with abundance of forbs and with fire frequency. Our findings that species richness responds unimodally to an environmental-productivity gradient, and that fire exclusion increases woody vegetation and leads to loss

  16. Mine spoil prairies expand critical habitat for endangered and threatened amphibian and reptile species

    Science.gov (United States)

    Lannoo, Michael J.; Kinney, Vanessa C.; Heemeyer, Jennifer L.; Engbrecht, Nathan J.; Gallant, Alisa L.; Klaver, Robert W.

    2009-01-01

    Coal extraction has been occurring in the Midwestern United States for over a century. Despite the pre-mining history of the landscape as woodlands, spent surface coalfields are often reclaimed to grasslands. We assessed amphibian and reptile species on a large tract of coal spoil prairie and found 13 species of amphibians (nine frog and four salamander species) and 19 species of reptiles (one lizard, five turtle, and 13 snake species). Two state-endangered and three state species of special concern were documented. The amphibian diversity at our study site was comparable to the diversity found at a large restored prairie situated 175 km north, within the historic prairie peninsula.

  17. Grazing behavior and production characteristics among cows differing in residual feed intake while grazing late season Idaho rangeland

    Science.gov (United States)

    The objectives were to determine if cows classified as either low- or high-residual feed intake (LRFI or HRFI) differed in BW, BCS, and winter grazing activity over time. Thirty Hereford x Angus (LRFI = 16; HRFI = 14) 2-year-old cows grazed sagebrush-steppe for 78 d beginning 29 September 2016. Body...

  18. Effects of grazing system on production and parasitism of dairy breed heifers and steers grazing wet marginal grasslands

    DEFF Research Database (Denmark)

    Kristensen, Troels; Thamsborg, S.M.; Andersen, Refsgaard

    2006-01-01

    Production and endoparasitism of first grazing season Holstein heifers and steers were investigated over two grazing seasons. Studies were conducted on low-lying peaty soil. In year 2000, 40 animals were included in a 2x2 factorial, replicated experiment with two sexes (steers v. heifers) and two...

  19. Tier 2 guidelines and remediation of Tebuthiuron on a native prairie site

    Energy Technology Data Exchange (ETDEWEB)

    Bessie, K.; Harckham, N.; Dance, T. [EBA Engineering Consultants Ltd., Calgary, AB (Canada); Burk, A. [EnCana Corp., Calgary, AB (Canada); Stephenson, G. [Stantec Consulting, Guelph, ON (Canada); Corbet, B. [Access Analytical Laboratories Inc., Calgary, AB (Canada)

    2009-10-01

    Tebuthiuron is a sterilant used to control vegetation at upstream and midstream petroleum sites. This article discussed the remediation processes used to reclaim a native prairie site contaminated with tebuthiuron. The site was located within a dry mixed grass natural area. A literature review was conducted to establish soil eco-contact guidelines specific to tebuthiuron. A site-specific ecotoxicity assessment was then conducted using a liquid chromatograph to detect tebuthiuron limits in the contaminated soils. A soil sampling technique was used to delineate the affected areas at the site. Site soils were spiked with various concentrations of tebuthiuron ranging from 0.00003 mg/kg to 3000 mg/kg. Test species included a Folsomia candida, an earthworm, and 4 plant species. The study showed that the invertebrate species were less sensitive to tebuthiuron than the plant species. A groundwater assessment showed that tebuthiuron levels exceeded Tier 1 groundwater remediation guidelines. A multilayer hydro-geological model showed that remediation guidelines were orders of magnitude greater than Tier 1 groundwater remediation. A thermal desorption technique was used to remediate the site. 7 refs., 8 figs.

  20. Acoustic response of Helmholtz dampers in the presence of hot grazing flow

    Science.gov (United States)

    Ćosić, B.; Wassmer, D.; Terhaar, S.; Paschereit, C. O.

    2015-01-01

    Thermoacoustic instabilities are high amplitude instabilities of premixed gas turbine combustors. Cooled passive dampers are used to attenuate or suppress these instabilities in the combustion chamber. For the first time, the influence of temperature differences between the grazing flow in the combustor and the cross-flow emanating from the Helmholtz damper is comprehensively investigated in the linear and nonlinear amplitude regime. The flow field inside the resonator and in the vicinity of the neck is measured with high-speed particle image velocimetry for various amplitudes and at different momentum-flux ratios of grazing and purging flow. Seeding is used as a tracer to qualitatively assess the mixing of the grazing and purging flow as well as the ingestion into the neck of the resonator. Experimentally, the acoustic response for various temperature differences between grazing and purging flow is investigated. The multi-microphone method, in combination with two microphones flush-mounted in the resonator volume and two microphones in the plane of the resonator entrance, is used to determine the impedance of the Helmholtz resonator in the linear and nonlinear amplitude regime for various temperatures and different momentum-flux ratios. Additionally, a thermocouple was used to measure the temperature in the neck. The acoustic response and the temperature measurements are used to obtain the virtual neck length and the effective area jump from a detailed impedance model. This model is extended to include the observed acoustic energy dissipation caused by the density gradients at the neck vicinity. A clear correlation between temperature differences and changes of the mass end-correction is confirmed. The capabilities of the impedance model are demonstrated.

  1. Comparison of methods for estimating herbage intake in grazing dairy cows

    DEFF Research Database (Denmark)

    Hellwing, Anne Louise Frydendahl; Lund, Peter; Weisbjerg, Martin Riis

    2015-01-01

    Estimation of herbage intake is a challenge both under practical and experimental conditions. The aim of this study was to estimate herbage intake with different methods for cows grazing 7 h daily on either spring or autumn pastures. In order to generate variation between cows, the 20 cows per...... season, and the herbage intake was estimated twice during each season. Cows were on pasture from 8:00 until 15:00, and were subsequently housed inside and fed a mixed ration (MR) based on maize silage ad libitum. Herbage intake was estimated with nine different methods: (1) animal performance (2) intake...

  2. Effects of grazing strategy on limiting nitrate leaching in grazed grass-clover pastures on coarse sandy soil

    DEFF Research Database (Denmark)

    Hansen, Elly Møller; Eriksen, Jørgen; Søegaard, Karen

    2012-01-01

    -term mean. The experiment was initiated in a 4-yr-old grass-clover sward in south Denmark. Three treatments were as follows grazing only (G), spring cut followed by grazing (CG) and both spring and autumn cuts with summer grazing (CGC). Nitrate leaching was calculated by extracting water isolates from 80 cm......Urinations of ruminants on grazed pastures increase the risk of nitrate leaching. The study investigated the effect of reducing the length of the grazing season on nitrate leaching from a coarse sandy, irrigated soil during 2006–2007 and 2007–2008. In both years, precipitation was above the long...... depth using ceramic suction cups. Because of considerable variation in measured nitrate concentrations, the 32 installed suction cups per treatment were insufficient to reveal differences between treatments. However, weighted nitrate leaching estimations for G, CG and CGC showed estimated mean nitrate N...

  3. Nutrient addition shifts plant community composition towards earlier flowering species in some prairie ecoregions in the U.S. Central Plains.

    Directory of Open Access Journals (Sweden)

    Lori Biederman

    Full Text Available The distribution of flowering across the growing season is governed by each species' evolutionary history and climatic variability. However, global change factors, such as eutrophication and invasion, can alter plant community composition and thus change the distribution of flowering across the growing season. We examined three ecoregions (tall-, mixed, and short-grass prairie across the U.S. Central Plains to determine how nutrient (nitrogen (N, phosphorus, and potassium (+micronutrient addition alters the temporal patterns of plant flowering traits. We calculated total community flowering potential (FP by distributing peak-season plant cover values across the growing season, allocating each species' cover to only those months in which it typically flowers. We also generated separate FP profiles for exotic and native species and functional group. We compared the ability of the added nutrients to shift the distribution of these FP profiles (total and sub-groups across the growing season. In all ecoregions, N increased the relative cover of both exotic species and C3 graminoids that flower in May through August. The cover of C4 graminoids decreased with added N, but the response varied by ecoregion and month. However, these functional changes only aggregated to shift the entire community's FP profile in the tall-grass prairie, where the relative cover of plants expected to flower in May and June increased and those that flower in September and October decreased with added N. The relatively low native cover in May and June may leave this ecoregion vulnerable to disturbance-induced invasion by exotic species that occupy this temporal niche. There was no change in the FP profile of the mixed and short-grass prairies with N addition as increased abundance of exotic species and C3 graminoids replaced other species that flower at the same time. In these communities a disturbance other than nutrient addition may be required to disrupt phenological

  4. Grazing Affects Exosomal Circulating MicroRNAs in Cattle

    Science.gov (United States)

    Muroya, Susumu; Ogasawara, Hideki; Hojito, Masayuki

    2015-01-01

    Circulating microRNAs (c-miRNAs) are associated with physiological adaptation to acute and chronic aerobic exercise in humans. To investigate the potential effect of grazing movement on miRNA circulation in cattle, here we profiled miRNA expression in centrifugally prepared exosomes from the plasma of both grazing and housed Japanese Shorthorn cattle. Microarray analysis of the c-miRNAs resulted in detection of a total of 231 bovine exosomal miRNAs in the plasma, with a constant expression level of let-7g across the duration and cattle groups. Expression of muscle-specific miRNAs such as miR-1, miR-133a, miR-206, miR-208a/b, and miR-499 were undetectable, suggesting the mildness of grazing movement as exercise. According to validation by quantitative RT-PCR, the circulating miR-150 level in the grazing cattle normalized by the endogenous let-7g level was down-regulated after 2 and 4 months of grazing (P cattle equalized when the grazing cattle were returned to a housed situation. Likewise, the levels of miR-19b, miR-148a, miR-221, miR-223, miR-320a, miR-361, and miR-486 were temporarily lowered in the cattle at 1 and/or 2 month of grazing compared to those of the housed cattle (P cattle at 2 months of grazing (P = 0.044). The elevation of miR-451 level in the plasma was coincident with that in the biceps femoris muscle of the grazing cattle (P = 0.008), which suggests the secretion or intake of miR-451 between skeletal muscle cells and circulation during grazing. These results revealed that exosomal c-miRNAs in cattle were affected by grazing, suggesting their usefulness as molecular grazing markers and functions in physiological adaptation of grazing cattle associated with endocytosis, focal adhesion, axon guidance, and a variety of intracellular signaling, as predicted by bioinformatic analysis. PMID:26308447

  5. Resilience of South African communal grazing lands after the removal of high grazing pressure

    CSIR Research Space (South Africa)

    Harrison, YA

    1999-05-01

    Full Text Available , et al., 1990; Dahlberg, 1993; Scoones, 1993; Shackleton, 1993; Sullivan, 1996). Invariably `overstocking' and hence overgrazing are deemed to be responsible for the apparent degradation. Despite this o cial perspective, most communal lands have... ones (Kelly and Walker, 1976; O'Connor and Pickett, 1992; Parsons, et al., 1997). However, these studies have not indicated the permanence, or reversibility, of the measured changes, and the magnitude of grazing eC128ects is usually minor relative...

  6. Figure and finish of grazing incidence mirrors

    International Nuclear Information System (INIS)

    Takacs, P.Z.; Church, E.L.

    1989-08-01

    Great improvement has been made in the past several years in the quality of optical components used in synchrotron radiation (SR) beamlines. Most of this progress has been the result of vastly improved metrology techniques and instrumentation permitting rapid and accurate measurement of the surface finish and figure on grazing incidence optics. A significant theoretical effort has linked the actual performance of components used as x-ray wavelengths to their topological properties as measured by surface profiling instruments. Next-generation advanced light sources will require optical components and systems to have sub-arc second surface figure tolerances. This paper will explore the consequences of these requirements in terms of manufacturing tolerances to see if the present manufacturing state-of-the-art is capable of producing the required surfaces. 15 refs., 14 figs., 2 tabs

  7. Axial grazing collisions with insulator surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Gravielle, M.S. [Instituto de Astronomia y Fisica del Espacio (IAFE), Consejo Nacional de Investigaciones Cientificas y Tecnicas, Casilla de Correo 67, Sucursal 28, 1428 Buenos Aires (Argentina) and Departamento de Fisica, FCEN, Universidad de Buenos Aires (Argentina)]. E-mail: msilvia@iafe.uba.ar; Miraglia, J.E. [Instituto de Astronomia y Fisica del Espacio (IAFE), Consejo Nacional de Investigaciones Cientificas y Tecnicas, Casilla de Correo 67, Sucursal 28, 1428 Buenos Aires (Argentina); Departamento de Fisica, FCEN, Universidad de Buenos Aires (Argentina)

    2007-05-15

    Electron capture and emission processes from insulator surfaces produced by grazing impact of fast ions are investigated under axial incidence conditions. For crystal surfaces we develop a model based on distorted wave methods, which allows us to express the coherent transition amplitude along the projectile path as a sum of atomic amplitudes, each one associated with a different lattice site. The method is applied to 100 keV protons colliding with LiF surfaces. For electron transitions from a given initial crystal state, the probabilities display strong interference effects as a function of the crystal orientation. But the interference patterns disappear when these partial probabilities are added to derive the total probability from the surface band.

  8. Axial grazing collisions with insulator surfaces

    International Nuclear Information System (INIS)

    Gravielle, M.S.; Miraglia, J.E.

    2007-01-01

    Electron capture and emission processes from insulator surfaces produced by grazing impact of fast ions are investigated under axial incidence conditions. For crystal surfaces we develop a model based on distorted wave methods, which allows us to express the coherent transition amplitude along the projectile path as a sum of atomic amplitudes, each one associated with a different lattice site. The method is applied to 100 keV protons colliding with LiF surfaces. For electron transitions from a given initial crystal state, the probabilities display strong interference effects as a function of the crystal orientation. But the interference patterns disappear when these partial probabilities are added to derive the total probability from the surface band

  9. Effect of strategies regarding concentrate supplementation and day-time grazing on N utilization at both field and dairy cow level

    DEFF Research Database (Denmark)

    Lund, Peter; Søegaard, Karen; Weisbjerg, Martin Riis

    2008-01-01

    N utilization at cow and field level was examined over two grazing periods of 30 days with 64 Holstein dairy cows. At cow and field level the effect of sward type (diploid vs. tetraploid perennial ryegrass, both mixed with white clover) and compressed sward height (6 vs. 10 cm) was examined....

  10. Poultry performance in different grazing densities: forage characteristics, losses due to grazing and feed intake

    Directory of Open Access Journals (Sweden)

    Luciano Cristiano França

    2014-02-01

    Full Text Available Morphological characteristics of three forage species grazed by rustic poultry in stocking were evaluated. Coast-cross fodder, kikuyu grass, and stylosanthes were planted in 33-m2 paddocks with two densities (m2/animal: D1 = 3m2/animal and D2 = 1m2/animal. The design was a randomized complete block with a 3 x 2 factorial (three grasses and two densities and three replications. Grass canopy height, grass mass, morphological composition (leaf, stem, and dead material, losses due to grazing, poultry weight gain and consumption, and concentrate feed conversion ratio and efficiency were evaluated. At the end of the experiment, forage and leaves masses were considered low to stylosanthes in D2 (0.28 to 0.03 kg/m2 and to kikuyu grass in D1 (0.13 to 0.05 kg/m2 and in D2 (0.11 and 0.03 kg/m2, respectively. In addition, the grass canopy height was considered low for stylosanthes (6.50 cm that could jeopardize the entry of new poultry lot. The three grass species had similar weight gain and revealed better results for 3m²/ chicken (3.20 kg/animal. Coast-cross fodder, kikuyu grass, and stylosanthes, with some exceptions, can be considered suitable for grazing fattening poultry at 3m2/animal at the evaluated time of the year (autumn.

  11. Riparian Meadow Response to Modern Conservation Grazing Management

    Science.gov (United States)

    Oles, Kristin M.; Weixelman, Dave A.; Lile, David F.; Tate, Kenneth W.; Snell, Laura K.; Roche, Leslie M.

    2017-09-01

    Riparian meadows occupy a small proportion of the public lands in the western United States but they provide numerous ecosystem services, including the production of high-quality forage for livestock grazing. Modern conservation management strategies (e.g., reductions in livestock stocking rates and adoption of new riparian grazing standards) have been implemented to better balance riparian conservation and livestock production objectives on publicly managed lands. We examined potential relationships between long-term changes in plant community, livestock grazing pressure and environmental conditions at two spatial scales in meadows grazed under conservation management strategies. Changes in plant community were not associated with either livestock stocking rate or precipitation at the grazing allotment (i.e., administrative) scale. Alternatively, both grazing pressure and precipitation had significant, albeit modest, associations with changes in plant community at the meadow (i.e., ecological site) scale. These results suggest that reductions in stocking rate have improved the balance between riparian conservation and livestock production goals. However, associations between elevation, site wetness, precipitation, and changes in plant community suggest that changing climate conditions (e.g., reduced snowpack and changes in timing of snowmelt) could trigger shifts in plant communities, potentially impacting both conservation and agricultural services (e.g., livestock and forage production). Therefore, adaptive, site-specific management strategies are required to meet grazing pressure limits and safeguard ecosystem services within individual meadows, especially under more variable climate conditions.

  12. Investigation of the Transcriptome of Prairie Cord Grass, a New Cellulosic Biomass Crop

    Directory of Open Access Journals (Sweden)

    Kristene Gedye

    2010-09-01

    Full Text Available Prairie cordgrass ( Bosc ex Link is being developed as a cellulosic biomass crop. Development of this species will require numerous steps, including breeding, agronomy, and characterization of the species genome. The research in this paper describes the first investigation of the transcriptome of prairie cordgrass via Next Generation Sequencing Technology, 454 GS FLX. A total of 556,198 expressed sequence tags (ESTs were produced from four prairie cordgrass tissues: roots, rhizomes, immature inflorescence, and hooks. These ESTs were assembled into 26,302 contigs and 71,103 singletons. From these data were identified, EST–SSR (simple sequence repeat regions and cell wall biosynthetic pathway genes suitable for the development of molecular markers which can aid the breeding process of prairie cordgrass by means of marker assisted selection.

  13. Influence of resource availability on Juniperus virginiana expansion in a forest–prairie ecotone

    Science.gov (United States)

    Despite being native to the United States, Juniperus virginiana has rapidly expanded in prairie ecosystems bringing detrimental ecological effects and increased wildfire risk. We transplanted J. virginiana seedlings in three plant communities to investigate mechanisms driving J. ...

  14. Anticoagulant Prairie Dog Bait Risk Mitigation Measures to Protect Endangered Species

    Science.gov (United States)

    This Web page contains information on how certified pesticide applicators can use anticoagulant prairie dog bait products such as Rozol and Kaput-D while minimizing exposure risks to listed and non-target species.

  15. Investigation of the Transcriptome of Prairie Cord Grass, a New Cellulosic Biomass Crop

    KAUST Repository

    Gedye, Kristene

    2010-09-15

    Prairie cordgrass (Spartina pectinata Bosc ex Link) is being developed as a cellulosic biomass crop. Development of this species will require numerous steps, including breeding, agronomy, and characterization of the species genome. The research in this paper describes the first investigation of the transcriptome of prairie cordgrass via Next Generation Sequencing Technology, 454 GS FLX. A total of 556,198 expressed sequence tags (ESTs) were produced from four prairie cordgrass tissues: roots, rhizomes, immature inflorescence, and hooks. These ESTs were assembled into 26,302 contigs and 71,103 singletons. From these data were identified, EST-SSR (simple sequence repeat) regions and cell wall biosynthetic pathway genes suitable for the development of molecular markers which can aid the breeding process of prairie cordgrass by means of marker assisted selection.

  16. FATTY ACID PROFILE IN MILK OF BOVEC SHEEP FED IN THE STABLE OR GRAZED IN DIFFERENT PASTURES

    Directory of Open Access Journals (Sweden)

    Angela Cividini

    2015-09-01

    Full Text Available The fatty acid profile in the milk of Bovec sheep fed total mixed ratio (TMR and grazed natural pastures in the lowland (480 m altitude supplemented with the second harvest (L as well as grazed different altitude mountain pastures; M1 (1100- 1300 m altitude, M2 (1600-1700 m altitude, M3 (1800 m altitude, M4 (1900 m altitude, M5 (2200 m altitude were determined. There was an important effect when ewes were turned from the stable to the pasture on all fatty acids. The percentage of α-linolenic acid (ALA, arachidonic acid (ARA and docosahexaenoic acid (DHA increased significantly (P<0.001 with the diet. In the milk from M5 grazing the percentage of ALA was 2.5 times higher than in milk from L and 2.6 times higher than in milk from TMR. The percentage of ARA and DHA in milk was the highest when ewes were grazing on the M5 pasture (0.21±0.02 wt. %; 0.22±0.02 wt. % respectively. Total n-3PUFA and n-6PUFA increased significantly (P<0.001 by the diet. Therefore, the n-6/n-3PUFA ratio was the best (1.2 in milk produced in the highest mountain pasture (M5, in terms of nutritional requirements.

  17. Widespread Use and Frequent Detection of Neonicotinoid Insecticides in Wetlands of Canada's Prairie Pothole Region

    OpenAIRE

    Main, Anson R.; Headley, John V.; Peru, Kerry M.; Michel, Nicole L.; Cessna, Allan J.; Morrissey, Christy A.

    2014-01-01

    Neonicotinoids currently dominate the insecticide market as seed treatments on Canada's major Prairie crops (e.g., canola). The potential impact to ecologically significant wetlands in this dominantly agro-environment has largely been overlooked while the distribution of use, incidence and level of contamination remains unreported. We modelled the spatial distribution of neonicotinoid use across the three Prairie Provinces in combination with temporal assessments of water and sediment concent...

  18. Social isolation induces behavioral and neuroendocrine disturbances relevant to depression in female and male prairie voles

    OpenAIRE

    Grippo, Angela J.; Gerena, Davida; Huang, Jonathan; Kumar, Narmda; Shah, Maulin; Ughreja, Raj; Carter, C. Sue

    2007-01-01

    Supportive social interactions may be protective against stressors and certain mental and physical illness, while social isolation may be a powerful stressor. Prairie voles are socially monogamous rodents that model some of the behavioral and physiological traits displayed by humans, including sensitivity to social isolation. Neuroendocrine and behavioral parameters, selected for their relevance to stress and depression, were measured in adult female and male prairie voles following 4 weeks o...

  19. Progress report: baseline monitoring of indicator species (butterflies) at tallgrass prairie restorations

    Science.gov (United States)

    Allain, Larry; Vidrine, Malcolm

    2014-01-01

    This project provides baseline data of butterfly populations at two coastal prairie restoration sites in Louisiana, the Duralde Unit of Lacassine National Wildlife Refuge (hereafter, the Duralde site) and the Cajun Prairie Restoration Project in Eunice (hereafter, the Eunice site). In all, four distinct habitat types representing different planting methods were sampled. These data will be used to assess biodiversity and health of native grasslands and also provide a basis for adaptive management.

  20. Mountain plover nest survival in relation to prairie dog and fire dynamics in shortgrass steppe

    Science.gov (United States)

    Augustine, David J.; Skagen, Susan K.

    2014-01-01

    Disturbed xeric grasslands with short, sparse vegetation provide breeding habitat for mountain plovers (Charadrius montanus) across the western Great Plains. Maintaining local disturbance regimes through prairie dog conservation and prescribed fire may contribute to the sustainability of recently declining mountain plover populations, but these management approaches can be controversial. We estimated habitat-specific mountain plover densities and nest survival rates on black-tailed prairie dog (Cynomys ludovicianus) colonies and burns in the shortgrass steppe of northeastern Colorado. Mountain plover densities were similar on prairie dog colonies (5.9 birds/km2; 95% CI = 4.7–7.4) and sites burned during the preceding dormant season (6.7 birds/km2; 95% CI = 4.6–9.6), whereas the 29-day nest survival rate was greater on prairie dog colonies (0.81 in 2011 and 0.39 in 2012) compared to the burned sites (0.64 in 2011 and 0.17 in 2012). Reduced nest survival in 2012 compared to 2011 was associated with higher maximum daily temperatures in 2012, consistent with a previous weather-based model of mountain plover nest survival in the southern Great Plains. Measurements of mountain plover density relative to time since disturbance showed that removal of prairie dog disturbance by sylvatic plague reduced mountain plover density by 70% relative to active prairie dog colonies after 1 year. Plover densities declined at a similar rate (by 78%) at burned sites between the first and second post-burn growing season. Results indicate that black-tailed prairie dog colonies are a particularly important nesting habitat for mountain plovers in the southern Great Plains. In addition, findings suggest that prescribed burning can be a valuable means to create nesting habitat in landscapes where other types of disturbances (such as prairie dog colonies) are limited in distribution and size. 

  1. Influence of richness and seeding density on invasion resistance in experimental tallgrass prairie restorations

    Science.gov (United States)

    Nemec, Kristine T.; Allen, Craig R.; Helzer, Christopher J.; Wedin, David A.

    2013-01-01

    In recent years, agricultural producers and non-governmental organizations and agencies have restored thousands of hectares of cropland to grassland in the Great Plains of the United States. However, little is known about the relationships between richness and seeding density in these restorations and resistance to invasive plant species. We assessed the effects of richness and seeding density on resistance to invasive and other unseeded plant species in experimental tallgrass prairie plots in central Nebraska. In 2006, twenty-four 55 m × 55 m plots were planted with six replicates in each of four treatments: high richness (97 species typically planted by The Nature Conservancy), at low and high seeding densities, and low richness (15 species representing a typical Conservation Reserve Program mix, CP25), at low and high seeding densities. There was a significant negative relationship between richness and basal cover of unseeded perennial forbs/legumes and unseeded perennial/annual grasses, abundance of bull thistle (Cirsium vulgare), and the number of inflorescences removed from smooth brome (Bromus inermis) transplants. Invasion resistance may have been higher in the high richness treatments because of the characteristics of the dominant species in these plots or because of greater interspecific competition for limiting resources among forbs/legumes with neighboring plants belonging to the same functional group. Seeding density was not important in affecting invasion resistance, except in the cover of unseeded grasses. Increasing seed mix richness may be more effective than increasing the seeding density for decreasing invasion by unseeded perennial species, bull thistle, and smooth brome.

  2. Plasma protein loss associated with gastrointestinal parasitism in grazing sheep.

    Science.gov (United States)

    Yakoob, A Y; Holmes, P H; Parkins, J J; Armour, J

    1983-01-01

    Some pathophysiological effects of parasitic gastroenteritis in two groups of lambs grazing paddocks either heavily or lightly contaminated with trichostrongyle larvae were investigated between July and October 1980. The leak of plasma protein was measured on three occasions at pasture using 51chromic chloride. Total faecal output was measured indirectly using chromic oxide. Losses of 51chromic chloride-labelled plasma protein into the gastrointestinal tract were significantly higher in the lambs grazing the heavily contaminated pasture than in those grazing lightly infected ground in both July and August. The increased plasma losses were associated with high faecal egg counts, hypoalbuminaemia and elevated levels of plasma pepsinogen.

  3. Aplanatic grazing incidence diffraction grating: a new optical element

    International Nuclear Information System (INIS)

    Hettrick, M.C.

    1986-01-01

    We present the theory of a grazing incidence reflection grating capable of imaging at submicron resolution. The optic is mechanically ruled on a spherical or cylindrical surface with varied groove spacings, delivering diffraction-limited response and a wide field of view at a selected wavelength. Geometrical aberrations are calculated on the basis of Fermat's principle, revealing significant improvements over a grazing incidence mirror. Aplanatic and quasi-aplanatic versions of the grating have applications in both imaging and scanning microscopes, microprobes, collimators, and telescopes. A 2-D crossed system of such gratings, similar to the grazing incidence mirror geometry of Kirkpatrick and Baez, could potentially provide spatial resolutions of --200 A

  4. Wildlife habitat management on the northern prairie landscape

    Science.gov (United States)

    Johnson, Douglas H.; Haseltine, Susan D.; Cowardin, Lewis M.

    1994-01-01

    The northern prairie landscape has changed dramatically within the past century as a result of settlement by Europeans. Natural ecosystems have been disrupted and wildlife populations greatly altered. Natural resource agencies control only limited areas within the landscape, which they cannot manage independently of privately owned lands. Wildlife managers need first to set quantifiable objectives, based on the survival, reproduction, and distribution of wildlife. Second, they need to build public support and partnerships for meeting those objectives. Finally, they need to evaluate progress not only with respect to attitudes of the public and partners but, more importantly, of the wildlife response. This paper describes some useful tools for managing information at all phases of this process. We follow by discussing management options at a landscape level. Examples are given that involve agency lands as well as private lands, managed for biological resources and diversity as well as economic sustainability.

  5. Classification of Prairie basins by their hysteretic connected functions

    Science.gov (United States)

    Shook, K.; Pomeroy, J. W.

    2017-12-01

    Diagnosing climate change impacts in the post-glacial landscapes of the North American Prairies through hydrological modelling is made difficult by drainage basin physiography. The region is cold, dry and flat with poorly developed stream networks, and so the basin area that is hydrologically connected to the stream outlet varies with basin depressional storage. The connected area controls the contributing area for runoff reaching the stream outlet. As depressional storage fills, ponds spill from one to another; the chain of spilling ponds allows water to flow over the landscape and increases the connected area of the basin. As depressional storage decreases, the connected fraction drops dramatically. Detailed, fine-scale models and remote sensing have shown that the relationship between connected area and the depressional storage is hysteretic in Prairie basins and that the nature of hysteresis varies with basin physiography. This hysteresis needs to be represented in hydrological models to calculate contributing area, and therefore streamflow hydrographs. Parameterisations of the hysteresis are needed for large-scale models used for climate change diagnosis. However, use of parameterisations of hysteresis requires guidance on how to represent them for a particular basin. This study shows that it is possible to relate the shape of hysteretic functions as determined by detailed models to the overall physiography of the basin, such as the fraction of the basin below the outlet, and remote sensing estimates of depressional storage, using the size distribution and location of maximum ponded water areas. By classifying basin physiography, the hysteresis of connected area - storage relationships can be estimated for basins that do not have high-resolution topographic data, and without computationally-expensive high-resolution modelling.

  6. Impact of processing on in vitro digestion of milk from grazing organic and confined conventional herds

    Science.gov (United States)

    Debate on differences between milk from grazing and non-grazing cows has not addressed the effects that standard processing may have on milk digestibility. In this study, raw milk from grazing organic (ORG) and non-grazing conventional (CONV) herds was adjusted to 0 and 3.25% fat and processed as fo...

  7. The effect of grazing on cow mortality in Danish dairy herds

    DEFF Research Database (Denmark)

    Burow, Elke; Thomsen, Peter Thorup; Sørensen, Jan Tind

    2011-01-01

    The effect of summer grazing in large Danish dairy herds and certain management characteristics of grazing were studied for their impact on dairy cow mortality. Mortality data (from the Danish Cattle Database) from 391 Danish dairy herds (>100 cows) were combined with information from...... a questionnaire survey of grazing procedures on these herds in 2008. In all, 131 of the herds were identified as summer grazing and 260 as zero-grazing herds. The mortality was affected by an interaction of summer grazing and milking system. The risk of a cow dying was reduced to 46% in a grazing compared...... and pasture was associated with increased cow mortality....

  8. Herds of methane chambers grazing bubbles

    Science.gov (United States)

    Grinham, Alistair; Dunbabin, Matthew

    2014-05-01

    Water to air methane emissions from freshwater reservoirs can be dominated by sediment bubbling (ebullitive) events. Previous work to quantify methane bubbling from a number of Australian sub-tropical reservoirs has shown that this can contribute as much as 95% of total emissions. These bubbling events are controlled by a variety of different factors including water depth, surface and internal waves, wind seiching, atmospheric pressure changes and water levels changes. Key to quantifying the magnitude of this emission pathway is estimating both the bubbling rate as well as the areal extent of bubbling. Both bubbling rate and areal extent are seldom constant and require persistent monitoring over extended time periods before true estimates can be generated. In this paper we present a novel system for persistent monitoring of both bubbling rate and areal extent using multiple robotic surface chambers and adaptive sampling (grazing) algorithms to automate the quantification process. Individual chambers are self-propelled and guided and communicate between each other without the need for supervised control. They can maintain station at a sampling site for a desired incubation period and continuously monitor, record and report fluxes during the incubation. To exploit the methane sensor detection capabilities, the chamber can be automatically lowered to decrease the head-space and increase concentration. The grazing algorithms assign a hierarchical order to chambers within a preselected zone. Chambers then converge on the individual recording the highest 15 minute bubbling rate. Individuals maintain a specified distance apart from each other during each sampling period before all individuals are then required to move to different locations based on a sampling algorithm (systematic or adaptive) exploiting prior measurements. This system has been field tested on a large-scale subtropical reservoir, Little Nerang Dam, and over monthly timescales. Using this technique

  9. Phosphorus and the grazing ruminant. 2. The effects of ...

    African Journals Online (AJOL)

    Department of Animal Science, University of Stellenbosch, Stellenbosch. The effects of .... rosis, severely impaired locomotion and therefore grazing behaviour ..... Studies in mineral metabolism. XXXVII. The influence of variations in the dietary ...

  10. Small mammal communities on cattle and game grazing areas in ...

    African Journals Online (AJOL)

    Small mammal communities on cattle and game grazing areas in Namibia. ... small mammal communities on two differently managed farmlands (cattle and game farm) in Namibia over the course of one year. ... AJOL African Journals Online.

  11. Assessment of the Effects of Emerging Grazing Policies on Land ...

    African Journals Online (AJOL)

    ADOWIE PERE

    ABSTRACT: This study examines the effects of the emerging grazing policies on land degradation in Nigeria using soil, vegetation ... imposed land use controls divorced from economic and demographic ... may be either positive or negative.

  12. Animal health management practices in zero grazing dairy units in ...

    African Journals Online (AJOL)

    Animal health management practices in zero grazing dairy units in Arusha City, Tanzania. ... African Journal of Food, Agriculture, Nutrition and Development ... findings, majority (84.6%) of the cow's enclosures were of poor hygiene.

  13. High motility reduces grazing mortality of planktonic bacteria

    DEFF Research Database (Denmark)

    Matz, Carsten; Jurgens, K.

    2005-01-01

    We tested the impact of bacterial swimming speed on the survival of planktonic bacteria in the presence of protozoan grazers. Grazing experiments with three common bacterivorous nanoflagellates revealed low clearance rates for highly motile bacteria. High-resolution video microscopy demonstrated...... size revealed highest grazing losses for moderately motile bacteria with a cell size between 0.2 and 0.4 mum(3). Grazing mortality was lowest for cells of >0.5 mum(3) and small, highly motile bacteria. Survival efficiencies of >95% for the ultramicrobacterial isolate CP-1 (less than or equal to0.1 mum......(3), >50 mum s(-1)) illustrated the combined protective action of small cell size and high motility. Our findings suggest that motility has an important adaptive function in the survival of planktonic bacteria during protozoan grazing....

  14. Ecological status of species on grazing gradients on the shallow ...

    African Journals Online (AJOL)

    Ecological status of species on grazing gradients on the shallow soils of the western ... Open Access DOWNLOAD FULL TEXT ... Vegetation data were gathered in such a way that those of different successional stages could be identified.

  15. Alterations in serotonin receptor-induced contractility of bovine lateral saphenous vein in cattle grazing endophyte-infected tall fescue.

    Science.gov (United States)

    Klotz, J L; Brown, K R; Xue, Y; Matthews, J C; Boling, J A; Burris, W R; Bush, L P; Strickland, J R

    2012-02-01

    As part of a 2-yr study documenting the physiologic impact of grazing endophyte-infected tall fescue on growing cattle, 2 experiments were conducted to characterize and evaluate effects of grazing 2 levels of toxic endophyte-infected tall fescue pastures on vascular contractility and serotonin receptors. Experiment 1 examined vasoconstrictive activities of 5-hydroxytryptamine (5HT), α-methylserotonin (ME5HT; a 5HT(2) receptor agonist), d-lysergic acid (LSA), and ergovaline (ERV) on lateral saphenous veins collected from steers immediately removed from a high-endophyte-infected tall fescue pasture (HE) or a low-endophyte-infected mixed-grass (LE) pasture. Using the same pastures, Exp. 2 evaluated effects of grazing 2 levels of toxic endophyte-infected tall fescue on vasoconstrictive activities of (±)-1-(2,5-dimethoxy-4-iodophenyl)-2-aminopropane hydrochloride (DOI), BW 723C86 (BW7), CGS-12066A (CGS), and 5-carboxamidotryptamine hemiethanolate maleate (5CT), agonists for 5HT(2A),( 2B), 5HT(1B), and 5HT(7) receptors, respectively. One-half of the steers in Exp. 2 were slaughtered immediately after removal from pasture, and the other one-half were fed finishing diets for >91 d before slaughter. For Exp. 1, maximal contractile intensities were greater (P 91 d. Experiment 1 demonstrated that grazing of HE pastures for 89 to 105 d induces functional alterations in blood vessels, as evidenced by reduced contractile capacity and altered serotonergic receptor activity. Experiment 2 demonstrated that grazing HE pastures alters vascular responses, which may be mediated through altered serotonin receptor activities, and these alterations may be ameliorated by the removal of ergot alkaloid exposure as demonstrated by the absence of differences in finished steers.

  16. Floodplains as a source of fine sediment in grazed landscapes: Tracing the source of suspended sediment in the headwaters of an intensively managed agricultural landscape

    Science.gov (United States)

    Yu, Mingjing; Rhoads, Bruce L.

    2018-05-01

    The flux of fine sediment within agricultural watersheds is an important factor determining the environmental quality of streams and rivers. Despite this importance, the contributions of sediment sources to suspended sediment loads within intensively managed agricultural watersheds remain poorly understood. This study assesses the provenance of fine suspended sediment in the headwater portion of a river flowing through an agricultural landscape in Illinois. Sediment source samples were collected from five sources: croplands, forested floodplains, grasslands, upper grazed floodplains, and lower grazed floodplains. Event-based and aggregated suspended sediment samples were collected from the stream at the watershed outlet. Quantitative geochemical fingerprinting techniques and a mixing model were employed to estimate the relative contributions of sediment from the five sources to the suspended sediment loads. To account for possible effects of small sample sizes, the analysis was repeated with only two sources: grazed floodplains and croplands/grasslands/forested floodplains. Results based on mean values of tracers indicate that the vast majority of suspended sediment within the stream (>95%) is derived from erosion of channel banks and the soil surface within areas of grazed floodplains. Uncertainty analysis based on Monte Carlo simulations indicates that mean values of tracer properties, which do not account for sampling variability in these properties, probably overestimate contributions from the two major sources. Nevertheless, this analysis still supports the conclusion that floodplain erosion accounts for the largest percentage of instream sediment (≈55-75%). Although grazing occurs over only a small portion of the total watershed area, grazed floodplains, which lie in close proximity to the stream channel, are an important source of sediment in this headwater steam system. Efforts to reduce fluxes of fine sediment in this intensively managed landscape should

  17. Relatedness of Macrophomina phaseolina isolates from tallgrass prairie, maize, soybean and sorghum.

    Science.gov (United States)

    Saleh, A A; Ahmed, H U; Todd, T C; Travers, S E; Zeller, K A; Leslie, J F; Garrett, K A

    2010-01-01

    Agricultural and wild ecosystems may interact through shared pathogens such as Macrophomina phaseolina, a generalist clonal fungus with more than 284 plant hosts that is likely to become more important under climate change scenarios of increased heat and drought stress. To evaluate the degree of subdivision in populations of M. phaseolina in Kansas agriculture and wildlands, we compared 143 isolates from maize fields adjacent to tallgrass prairie, nearby sorghum fields, widely dispersed soybean fields and isolates from eight plant species in tallgrass prairie. Isolate growth phenotypes were evaluated on a medium containing chlorate. Genetic characteristics were analysed based on amplified fragment length polymorphisms and the sequence of the rDNA-internal transcribed spacer (ITS) region. The average genetic similarity was 58% among isolates in the tallgrass prairie, 71% in the maize fields, 75% in the sorghum fields and 80% in the dispersed soybean fields. The isolates were divided into four clusters: one containing most of the isolates from maize and soybean, two others containing isolates from wild plants and sorghum, and a fourth containing a single isolate recovered from Solidago canadensis in the tallgrass prairie. Most of the sorghum isolates had the dense phenotype on media containing chlorate, while those from other hosts had either feathery or restricted phenotypes. These results suggest that the tallgrass prairie supports a more diverse population of M. phaseolina per area than do any of the crop species. Subpopulations show incomplete specialization by host. These results also suggest that inoculum produced in agriculture may influence tallgrass prairie communities, and conversely that different pathogen subpopulations in tallgrass prairie can interact there to generate 'hybrids' with novel genetic profiles and pathogenic capabilities.

  18. Effects of Grazing Management in Brachiaria grass-forage Peanut Pastures on Canopy Structure and Forage Intake.

    Science.gov (United States)

    Gomes, F K; Oliveira, M D B L; Homem, B G C; Boddey, R M; Bernardes, T F; Gionbelli, M P; Lara, M A S; Casagrande, D R

    2018-06-13

    Maintenance of mixed grass-legume pastures for stand longevity and improved animal utilization is a challenge in warm-season climates. The goal of this study was to assess grazing management on stand persistence, forage intake, and N balance of beef heifers grazing mixed pastures of Brachiaria brizantha and Arachis pintoi. A two-year experiment was carried out in Brazil, where four grazing management were assessed: rest period interrupted at 90%, 95%, and 100% of light interception (LI) and a fixed rest period of 42 days (90LI, 95LI, 100LI, and 42D, respectively). The LI were taken at 50 points at ground level and at five points above the canopy for each paddock using a canopy analyzer. For all treatments, the post-grazing stubble height was 15 cm. Botanical composition and canopy structure characteristics such as canopy height, forage mass, and vertical distribution of the morphological composition were evaluated pre-and post-grazing. Forage chemical composition, intake, and microbial synthesis were also determined. A randomized complete block design was used, considering the season of the year as a repeated measure over time. Grazing management and season were considered fixed, while block and year were considered random effects. In the summer, legume mass accounted for 19% of the canopy at 100LI, which was less than other treatments (a mean of 30%). The 100LI treatment had a greater grass stem mass compared with other treatments. In terms of vertical distribution for 100LI, 38.6% of the stem mass was above the stubble height, greater than the 5.7% for other treatments. The canopy structure limited neutral detergent fiber intake (P = 0.007) at 100LI (1.02% of BW/d), whereas 42D, 90LI, and 95LI treatments had NDF intake close to 1.2% of BW/d. The intake of digestible organic matter (OM; P = 0.007) and the ratio of crude protein/digestible OM (P < 0.001) were less at 100LI in relation to the other treatments. The production of microbial N (P < 0.001) and efficiency

  19. Soil modification by invasive plants: Effects on native and invasive species of mixed-grass prairies

    Science.gov (United States)

    Jordan, N.R.; Larson, D.L.; Huerd, S.C.

    2008-01-01

    Invasive plants are capable of modifying attributes of soil to facilitate further invasion by conspecifics and other invasive species. We assessed this capability in three important plant invaders of grasslands in the Great Plains region of North America: leafy spurge (Euphorbia esula), smooth brome (Bromus inermis) and crested wheatgrass (Agropyron cristatum). In a glasshouse, these three invasives or a group of native species were grown separately through three cycles of growth and soil conditioning in both steam-pasteurized and non-pasteurized soils, after which we assessed seedling growth in these soils. Two of the three invasive species, Bromus and Agropyron, exhibited significant self-facilitation via soil modification. Bromus and Agropyron also had significant facilitative effects on other invasives via soil modification, while Euphorbia had significant antagonistic effects on the other invasives. Both Agropyron and Euphorbia consistently suppressed growth of two of three native forbs, while three native grasses were generally less affected. Almost all intra- and interspecific effects of invasive soil conditioning were dependent upon presence of soil biota from field sites where these species were successful invaders. Overall, these results suggest that that invasive modification of soil microbiota can facilitate plant invasion directly or via 'cross-facilitation' of other invasive species, and moreover has potential to impede restoration of native communities after removal of an invasive species. However, certain native species that are relatively insensitive to altered soil biota (as we observed in the case of the forb Linum lewisii and the native grasses), may be valuable as 'nurse'species in restoration efforts. ?? 2007 Springer Science+Business Media B.V.

  20. Soil Aggregate Stability and Grassland Productivity Associations in a Northern Mixed-Grass Prairie.

    Directory of Open Access Journals (Sweden)

    Kurt O Reinhart

    Full Text Available Soil aggregate stability data are often predicted to be positively associated with measures of plant productivity, rangeland health, and ecosystem functioning. Here we revisit the hypothesis that soil aggregate stability is positively associated with plant productivity. We measured local (plot-to-plot variation in grassland community composition, plant (aboveground biomass, root biomass, % water-stable soil aggregates, and topography. After accounting for spatial autocorrelation, we observed a negative association between % water-stable soil aggregates (0.25-1 and 1-2 mm size classes of macroaggregates and dominant graminoid biomass, and negative associations between the % water-stable aggregates and the root biomass of a dominant sedge (Carex filifolia. However, variation in total root biomass (0-10 or 0-30 cm depths was either negatively or not appreciably associated with soil aggregate stabilities. Overall, regression slope coefficients were consistently negative thereby indicating the general absence of a positive association between measures of plant productivity and soil aggregate stability for the study area. The predicted positive association between factors was likely confounded by variation in plant species composition. Specifically, sampling spanned a local gradient in plant community composition which was likely driven by niche partitioning along a subtle gradient in elevation. Our results suggest an apparent trade-off between some measures of plant biomass production and soil aggregate stability, both known to affect the land's capacity to resist erosion. These findings further highlight the uncertainty of plant biomass-soil stability associations.

  1. Contrasting nest survival patterns for ducks and songbirds in northern mixed-grass prairie

    Science.gov (United States)

    Grant, Todd; Shaffer, Terry L.; Madden, Elizabeth M.; Nenneman, Melvin P.

    2017-01-01

    Management actions intended to protect or improve habitat for ducks may benefit grassland-nesting passerines, but scant information is available to explore this assumption. During 1998–2003, we examined nest survival of ducks and songbirds to determine whether effects of prescribed fire and other habitat features (e.g., shrub cover and distance to habitat edges) were similar for ducks and passerines breeding in North Dakota. We used the logistic-exposure method to estimate survival of duck and songbird nests (n = 3,171). We used an information-theoretic approach to identify factors that most influenced nest survival. Patterns of nest survival were markedly different between taxonomic groups. For ducks, nest survival was greater during the first postfire nesting season (daily survival rate [DSR] = 0.957, 85% CI = 0.951–0.963), relative to later postfire nesting seasons (DSR = 0.946, 85% CI = 0.942–0.950). Furthermore duck nest survival and nest densities were inversely related. Duck nest survival also was greater as shrub cover decreased and as distance from cropland and wetland edges increased. Passerines had lower nest survival during the first postfire nesting season (DSR = 0.934, 85% CI = 0.924–0.944), when densities also were low compared to subsequent postfire nesting seasons (DSR = 0.947, 85% CI = 0.944–0.950). Parasitism by brown-headed cowbirds (Molothrus ater) reduced passerine nest survival and this effect was more pronounced during the first postfire nesting season compared to subsequent nesting seasons. Passerine nest survival was greater as shrub cover decreased and perhaps for more concealed nests. Duck and songbird nest survival rates were not correlated during this study and for associated studies that examined additional variables using the same dataset, suggesting that different mechanisms influenced their survival. Based on our results, ducks should not be considered direct surrogates for passerines when predicting effects of prescribed fire, shrub cover, and habitat edges on nest survival.

  2. Direct and indirect effects of climate change on a prairie plant community.

    Directory of Open Access Journals (Sweden)

    Peter B Adler

    2009-09-01

    Full Text Available Climate change directly affects species by altering their physical environment and indirectly affects species by altering interspecific interactions such as predation and competition. Recent studies have shown that the indirect effects of climate change may amplify or counteract the direct effects. However, little is known about the the relative strength of direct and indirect effects or their potential to impact population persistence.We studied the effects of altered precipitation and interspecific interactions on the low-density tiller growth rates and biomass production of three perennial grass species in a Kansas, USA mixed prairie. We transplanted plugs of each species into local neighborhoods of heterospecific competitors and then exposed the plugs to a factorial manipulation of growing season precipitation and neighbor removal. Precipitation treatments had significant direct effects on two of the three species. Interspecific competition also had strong effects, reducing low-density tiller growth rates and aboveground biomass production for all three species. In fact, in the presence of competitors, (log tiller growth rates were close to or below zero for all three species. However, we found no convincing evidence that per capita competitive effects changed with precipitation, as shown by a lack of significant precipitation x competition interactions.We found little evidence that altered precipitation will influence per capita competitive effects. However, based on species' very low growth rates in the presence of competitors in some precipitation treatments, interspecific interactions appear strong enough to affect the balance between population persistence and local extinction. Therefore, ecological forecasting models should include the effect of interspecific interactions on population growth, even if such interaction coefficients are treated as constants.

  3. Rotation grazing as a conservation management tool : Vegetation changes after six years of application in a salt marsh ecosystem

    NARCIS (Netherlands)

    Lagendijk, D. D. Georgette; Howison, Ruth A.; Esselink, Peter; Ubels, Richard; Smit, Christian

    2017-01-01

    Grazing is commonly used in conservation to promote biodiversity, but the search for a grazing management regime that optimises biodiversity is still ongoing. Rotation grazing, where grazing is followed by a relatively long period of non-grazing, is a relative new tool in conservation management,

  4. Population Dynamics and Transcriptomic Responses of Chorthippus albonemus (Orthoptera: Acrididae to Herbivore Grazing Intensity

    Directory of Open Access Journals (Sweden)

    Xinghu Qin

    2017-11-01

    Full Text Available Livestock grazing can trigger outbreaks of insect pests in steppe ecosystems of Inner Mongolia in China. However, the physiological responses of the grasshopper Chorthippus albonemus to grazing are not well-understood. Here we investigated the effects of sheep grazing on the population dynamics and transcriptomic response of C. albonemus. We collected the insects three times (about 20 days apart in 1.33-ha plots in which there were no grazing, light grazing, moderate grazing, heavy grazing, or overgrazing. Our results showed that continuous grazing significantly decreased plant biomass and influenced plant succession. Total insect species diversity significantly declined along the grazing intensity gradient and over time. Results of the first two collections of C. albonemus indicated that moderate grazing significantly increased the abundance of C. albonemus. However, abundance was significantly decreased in plots that were overgrazed, possibly because of food stress and environmental pressures. Under moderate grazing, betA and CHDH genes were significantly upregulated in C. albonemus. In response to higher grazing intensity, upregulated genes included those involved in serine-type peptidase activity, anatomical structure development, and sensory organ development; downregulated genes included those involved in the structural constituents of the ribosome and ribosome processes. Genes strongly upregulated in response to heavy grazing pressure included adaptive genes such as those encoding ankyrin repeat domain-containing protein and HSP. These findings improve our understanding of the role of the transcriptome in C. albonemus population response to livestock grazing and may provide useful targets for grasshopper control.

  5. The development and adoption of conservation tillage systems on the Canadian Prairies

    Directory of Open Access Journals (Sweden)

    L. Awada

    2014-03-01

    Full Text Available One of the major agricultural innovations on the Canadian Prairies over the last 40 years has been the introduction of conservation tillage (CT. Conservation tillage-a system that includes minimum and zero tillage (ZT -was introduced as an alternative to traditional (conventional tillage (TT to control soil degradation and to promote agricultural sustainability. The development and adoption of CT systems involved pioneer farmers, engineers, scientists, and farmer associations. By the end of the 1970s, CT started to take shape on the Prairies, but for a number of economic, technical, political and social reasons, the adoption of CT did not occur on any major scale before the 1990s. Today, more than 75% of the Prairie's cropland is under some form of CT with more than 50% under ZT. In this paper, the factors behind the development and adoption of conservation tillage technology on the Prairies in the period between 1930 and 2011 are reviewed. Then, some of the benefits of the adoption of CT on the Prairies are highlighted. The data show that CT and ZT became profitable for the majority of farmers during and after the 1990s, and that the increased use of CT contributed to the dramatic decrease in the area under summerfallow and to the increase in the area sown to canola and pulse crops. These changes contributed to the reduction of all forms of land degradation and to decreases in agricultural greenhouse gas (GHG emissions.

  6. Factors that affect parasitism of black-tailed prairie dogs by fleas

    Science.gov (United States)

    Eads, David A.; Hoogland, John L.

    2016-01-01

    Fleas (Insecta: Siphonaptera) are hematophagous ectoparasites that feed on vertebrate hosts. Fleas can reduce the fitness of hosts by interfering with immune responses, disrupting adaptive behaviors, and transmitting pathogens. The negative effects of fleas on hosts are usually most pronounced when fleas attain high densities. In lab studies, fleas desiccate and die under dry conditions, suggesting that populations of fleas will tend to decline when precipitation is scarce under natural conditions. To test this hypothesis, we compared precipitation vs. parasitism of black-tailed prairie dogs (Cynomys ludovicianus) by fleas at a single colony during May and June of 13 consecutive years (1976–1988) at Wind Cave National Park, South Dakota, USA. The number of fleas on prairie dogs decreased with increasing precipitation during both the prior growing season (April through August of the prior year) and the just-completed winter–spring (January through April of current year). Due to the reduction in available moisture and palatable forage in dry years, herbivorous prairie dogs might have been food-limited, with weakened behavioral and immunological defenses against fleas. In support of this hypothesis, adult prairie dogs of low mass harbored more fleas than heavier adults. Our results have implications for the spread of plague, an introduced bacterial disease, transmitted by fleas, that devastates prairie dog colonies and, in doing so, can transform grassland ecosystems.

  7. Effects of sexual dimorphism and landscape composition on the trophic behavior of Greater Prairie-Chicken.

    Directory of Open Access Journals (Sweden)

    Beatriz Blanco-Fontao

    Full Text Available Partitioning of ecological niche is expected in lekking species that show marked sexual size dimorphism as a consequence of sex-specific ecological constraints. However, niche partitioning is uncertain in species with moderate sexual dimorphism. In addition, the ecological niche of a species may also be affected by landscape composition; particularly, agricultural fragmentation may greatly influence the trophic behavior of herbivores. We studied trophic niche variation in Greater Prairie-Chickens (Tympanuchus cupido, a grouse species that shows moderate sex-dimorphism. Greater Prairie-Chickens are native to tallgrass prairies of North America, although populations persist in less natural mosaics of cropland and native habitats. We used stable isotope analysis of carbon and nitrogen in blood, claws and feathers to assess seasonal differences in trophic niche breadth and individual specialization between male and female Greater Prairie-Chickens, and between birds living in continuous and fragmented landscapes. We found that females showed broader niches and higher individual specialization than males, especially in winter and autumn. However, differences between females and males were smaller in spring when birds converge at leks, suggesting that females and males may exhibit similar feeding behaviors during the lekking period. In addition, we found that birds living in native prairies showed greater annual trophic variability than conspecifics in agricultural mosaic landscapes. Native habitats may provide greater dietary diversity, resulting in greater diversity of feeding strategies.

  8. Trichostatin A (TSA) facilitates formation of partner preference in male prairie voles (Microtus ochrogaster).

    Science.gov (United States)

    Duclot, F; Wang, H; Youssef, C; Liu, Y; Wang, Z; Kabbaj, M

    2016-05-01

    In the socially monogamous prairie voles (Microtus ochrogaster), the development of a social bonding is indicated by the formation of partner preference, which involves a variety of environmental and neurochemical factors and brain structures. In a most recent study in female prairie voles, we found that treatment with the histone deacetylase inhibitor trichostatin A (TSA) facilitates the formation of partner preference through up-regulation of oxytocin receptor (OTR) and vasopressin V1a receptor (V1aR) genes expression in the nucleus accumbens (NAcc). In the present study, we tested the hypothesis that TSA treatment also facilitates partner preference formation and alters OTR and V1aR genes expression in the NAcc in male prairie voles. We thus observed that central injection of TSA dose-dependently promoted the formation of partner preference in the absence of mating in male prairie voles. Interestingly, TSA treatment up-regulated OTR, but not V1aR, gene expression in the NAcc similarly as they were affected by mating - an essential process for naturally occurring partner preference. These data, together with others, not only indicate the involvement of epigenetic events but also the potential role of NAcc oxytocin in the regulation of partner preference in both male and female prairie voles. Copyright © 2016 Elsevier Inc. All rights reserved.

  9. Assessment of lesser prairie-chicken use of wildlife water guzzlers

    Science.gov (United States)

    Boal, Clint W.; Borsdorf, Philip K.; Gicklhorn, Trevor S.

    2014-01-01

    Man-made water sources have been used as a management tool for wildlife, especially in arid regions, but the value of these water sources for wildlife populations is not well understood. In particular, the value of water as a conservation tool for Lesser Prairie-Chickens (Tympanuchus pallidicinctus) is unknown. However, this is a relevant issue due to a heightened conservation concern for the species and its occupancy of an arid landscape anticipated to experience warmer, drier springs and winters. We assessed if Lesser Prairie-Chickens would use commercially available wildlife water guzzlers and if there was any apparent selection between two design types. We confirmed that Lesser Prairie-Chickens would use bird friendly designed wildlife water guzzlers. Use was primarily during the lekking-nesting period (March–May) and the brood rearing period (June–July) and primarily by males. Although both designs were used, we found significantly greater use of a design that had a wider water trough and ramp built into the tank cover compared to a design that had a longer, narrower trough extending from the tank.Although we were unable to assess the physiological need of surface water by Lesser Prairie-Chickens, we were able to verify that they will use wildlife water guzzlers to access surface water. If it is found surface water is beneficial for Lesser Prairie-Chickens, game bird friendly designed guzzlers may be a useful conservation tool for the species.

  10. Hydrology of prairie wetlands: Understanding the integrated surface-water and groundwater processes

    Science.gov (United States)

    Hayashi, Masaki; van der Kamp, Garth; Rosenberry, Donald O.

    2016-01-01

    Wetland managers and policy makers need to make decisions based on a sound scientific understanding of hydrological and ecological functions of wetlands. This article presents an overview of the hydrology of prairie wetlands intended for managers, policy makers, and researchers new to this field (e.g., graduate students), and a quantitative conceptual framework for understanding the hydrological functions of prairie wetlands and their responses to changes in climate and land use. The existence of prairie wetlands in the semi-arid environment of the Prairie-Pothole Region (PPR) depends on the lateral inputs of runoff water from their catchments because mean annual potential evaporation exceeds precipitation in the PPR. Therefore, it is critically important to consider wetlands and catchments as highly integrated hydrological units. The water balance of individual wetlands is strongly influenced by runoff from the catchment and the exchange of groundwater between the central pond and its moist margin. Land-use practices in the catchment have a sensitive effect on runoff and hence the water balance. Surface and subsurface storage and connectivity among individual wetlands controls the diversity of pond permanence within a wetland complex, resulting in a variety of eco-hydrological functionalities necessary for maintaining the integrity of prairie-wetland ecosystems.

  11. Evaluating pasture and soil allowance of manganese for Kajli rams grazing in semi-arid environment.

    Science.gov (United States)

    Khan, Zafar Iqbal; Ahmad, Kafeel; Ashraf, Muhammad; Naqvi, Syed Ali Hassan; Seidavi, Alireza; Akram, Nudrat Aisha; Laudadio, Vito; Tufarelli, Vincenzo

    2015-03-01

    The current research on the manganese (Mn) transfer from soil to plant as well as to grazing Kajli rams in the form of sampling periods was carried out under semi-arid environmental conditions. Forage, soil and blood plasma samples were collected during 4 months of the year after a 1-month interval, and Mn concentrations were assessed after wet digestion using an atomic absorption spectrophotometer. Results showed that Mn concentration in soil ranged from 48.28 to 59.44 mg/kg, with incoherent augment and decline across sampling periods, and effect of sampling period on soil Mn was also found to be significant (P soil appeared higher than the critical value and sufficient for forage crop requirement. The Mn concentration in forage ranged between 24.8 and 37.2 mg/kg, resulting deficient based on the requirement allowance of Mn for livestock grazing animals, therein with almost unchanged forage Mn concentration. The Mn values in blood plasma of rams varied from 0.066 to 0.089 mg/l, with a consistent increase based on sampling period, and the effect of sampling periods on plasma Mn was found to be highly significant (P soil and plant species amassing capability on the transport of Mn in the soil-plant-animal system. Results indicated a much higher accumulation rate at the sampling characterized by vegetation dominated by legumes in comparison to grasses, crop residues and mixed pasture and a pronounced seasonal supply of Mn at the four sampling period of grazing land of diverse botanical composition.

  12. Unexpected Decrease in Milk Production after Fenbendazole Treatment of Dairy Cows during Early Grazing Season.

    Science.gov (United States)

    Ravinet, Nadine; Chartier, Christophe; Bareille, Nathalie; Lehebel, Anne; Ponnau, Adeline; Brisseau, Nadine; Chauvin, Alain

    2016-01-01

    Gastrointestinal nematodes (GIN) infection can impair milk production (MP) in dairy cows. To investigate whether MP would be optimized by spring targeted-selective anthelmintic treatment in grazing cows, we assessed (1) the effect on MP of an anthelmintic treatment applied 1.5 to 2 months after turn-out, and (2) herd and individual indicators associated with the post-treatment MP response. A randomized controlled clinical trial was conducted in 13 dairy farms (578 cows) in western France in spring 2012. In each herd, lactating cows of the treatment group received fenbendazole orally, control cows remained untreated. Daily cow MP was recorded from 2 weeks before until 15 weeks after treatment. Individual serum pepsinogen and anti-Ostertagia antibody levels (expressed as ODR), faecal egg count and bulk tank milk (BTM) Ostertagia ODR were measured at treatment time. Anthelmintic treatment applied during the previous housing period was recorded for each cow. In each herd, information regarding heifers' grazing and anthelmintic treatment history was collected to assess the Time of Effective Contact (TEC, in months) with GIN infective larvae before the first calving. The effect of treatment on weekly MP averages and its relationships with herd and individual indicators were studied using linear mixed models with two nested random effects (cow within herd). Unexpectedly, spring treatment had a significant detrimental effect on MP (-0.92 kg/cow/day on average). This negative MP response was particularly marked in high producing cows, in cows not treated during the previous housing period or with high pepsinogen levels, and in cows from herds with a high TEC or a high BTM ODR. This post-treatment decrease in MP may be associated with immuno-inflammatory mechanisms. Until further studies can assess whether this unexpected result can be generalized, non-persistent treatment of immunized adult dairy cows against GIN should not be recommended in early grazing season.

  13. Unexpected Decrease in Milk Production after Fenbendazole Treatment of Dairy Cows during Early Grazing Season.

    Directory of Open Access Journals (Sweden)

    Nadine Ravinet

    Full Text Available Gastrointestinal nematodes (GIN infection can impair milk production (MP in dairy cows. To investigate whether MP would be optimized by spring targeted-selective anthelmintic treatment in grazing cows, we assessed (1 the effect on MP of an anthelmintic treatment applied 1.5 to 2 months after turn-out, and (2 herd and individual indicators associated with the post-treatment MP response. A randomized controlled clinical trial was conducted in 13 dairy farms (578 cows in western France in spring 2012. In each herd, lactating cows of the treatment group received fenbendazole orally, control cows remained untreated. Daily cow MP was recorded from 2 weeks before until 15 weeks after treatment. Individual serum pepsinogen and anti-Ostertagia antibody levels (expressed as ODR, faecal egg count and bulk tank milk (BTM Ostertagia ODR were measured at treatment time. Anthelmintic treatment applied during the previous housing period was recorded for each cow. In each herd, information regarding heifers' grazing and anthelmintic treatment history was collected to assess the Time of Effective Contact (TEC, in months with GIN infective larvae before the first calving. The effect of treatment on weekly MP averages and its relationships with herd and individual indicators were studied using linear mixed models with two nested random effects (cow within herd. Unexpectedly, spring treatment had a significant detrimental effect on MP (-0.92 kg/cow/day on average. This negative MP response was particularly marked in high producing cows, in cows not treated during the previous housing period or with high pepsinogen levels, and in cows from herds with a high TEC or a high BTM ODR. This post-treatment decrease in MP may be associated with immuno-inflammatory mechanisms. Until further studies can assess whether this unexpected result can be generalized, non-persistent treatment of immunized adult dairy cows against GIN should not be recommended in early grazing season.

  14. Unexpected Decrease in Milk Production after Fenbendazole Treatment of Dairy Cows during Early Grazing Season

    Science.gov (United States)

    Ravinet, Nadine; Chartier, Christophe; Bareille, Nathalie; Lehebel, Anne; Ponnau, Adeline; Brisseau, Nadine; Chauvin, Alain

    2016-01-01

    Gastrointestinal nematodes (GIN) infection can impair milk production (MP) in dairy cows. To investigate whether MP would be optimized by spring targeted-selective anthelmintic treatment in grazing cows, we assessed (1) the effect on MP of an anthelmintic treatment applied 1.5 to 2 months after turn-out, and (2) herd and individual indicators associated with the post-treatment MP response. A randomized controlled clinical trial was conducted in 13 dairy farms (578 cows) in western France in spring 2012. In each herd, lactating cows of the treatment group received fenbendazole orally, control cows remained untreated. Daily cow MP was recorded from 2 weeks before until 15 weeks after treatment. Individual serum pepsinogen and anti-Ostertagia antibody levels (expressed as ODR), faecal egg count and bulk tank milk (BTM) Ostertagia ODR were measured at treatment time. Anthelmintic treatment applied during the previous housing period was recorded for each cow. In each herd, information regarding heifers’ grazing and anthelmintic treatment history was collected to assess the Time of Effective Contact (TEC, in months) with GIN infective larvae before the first calving. The effect of treatment on weekly MP averages and its relationships with herd and individual indicators were studied using linear mixed models with two nested random effects (cow within herd). Unexpectedly, spring treatment had a significant detrimental effect on MP (-0.92 kg/cow/day on average). This negative MP response was particularly marked in high producing cows, in cows not treated during the previous housing period or with high pepsinogen levels, and in cows from herds with a high TEC or a high BTM ODR. This post-treatment decrease in MP may be associated with immuno-inflammatory mechanisms. Until further studies can assess whether this unexpected result can be generalized, non-persistent treatment of immunized adult dairy cows against GIN should not be recommended in early grazing season. PMID

  15. Phenotypic and genetic characterization of wildland collections of western and Searls prairie clovers for rangeland revegetation in the western USA

    Science.gov (United States)

    Kishor Bhattarai

    2010-01-01

    Western prairie clover [Dalea ornata (Douglas ex Hook.) Eaton & J. Wright] is a perennial legume that occurs in the northern Great Basin, Snake River Basin, and southern Columbia Plateau, whereas Searls prairie clover [Dalea searlsiae (A. Gray) Barneby], also a perennial legume, occurs in the southern Great Basin and surrounding areas. Understanding the genetic and...

  16. Students' Perceptions of a Highly Controversial yet Keystone Species, the Black-Tailed Prairie Dog: A Case Study

    Science.gov (United States)

    Fox-Parrish, Lynne; Jurin, Richard R.

    2008-01-01

    The authors used a case-study methodology to explore the perceptions of 30 9th-grade biology students relative to black-tailed prairie dogs. The case study, which involved classroom- and field-based experiences that focused on black-tailed prairie dogs, revealed 3 major themes: apathy, egocentrism, and naive conceptions. The authors had hoped that…

  17. 75 FR 70021 - South Dakota Prairie Winds Project; Partial Term Relinquishment and Release of Easement for Wind...

    Science.gov (United States)

    2010-11-16

    ... requested financing for the project from the RUS. PW SD1 has also submitted an application to the Service to...] South Dakota Prairie Winds Project; Partial Term Relinquishment and Release of Easement for Wind Energy... impact statement (FEIS) on the South Dakota Prairie Winds Project issued by the Department of Energy's...

  18. Effects of past and present livestock grazing on herpetofauna in a landscape-scale experiment.

    Science.gov (United States)

    Kay, Geoffrey M; Mortelliti, Alessio; Tulloch, Ayesha; Barton, Philip; Florance, Daniel; Cunningham, Saul A; Lindenmayer, David B

    2017-04-01

    Livestock grazing is the most widespread land use on Earth and can have negative effects on biodiversity. Yet, many of the mechanisms by which grazing leads to changes in biodiversity remain unresolved. One reason is that conventional grazing studies often target broad treatments rather than specific parameters of grazing (e.g., intensity, duration, and frequency) or fail to account for historical grazing effects. We conducted a landscape-scale replicated grazing experiment (15,000 km 2 , 97 sites) to examine the impact of past grazing management and current grazing regimes (intensity, duration, and frequency) on a community of ground-dwelling herpetofauna (39 species). We analyzed community variables (species richness and composition) for all species and built multiseason patch-occupancy models to predict local colonization and extinction for the 7 most abundant species. Past grazing practices did not influence community richness but did affect community composition and patch colonization and extinction for 4 of 7 species. Present grazing parameters did not influence community richness or composition, but 6 of the 7 target species were affected by at least one grazing parameter. Grazing frequency had the most consistent influence, positively affecting 3 of 7 species (increased colonization or decreased extinction). Past grazing practice affected community composition and population dynamics in some species in different ways, which suggests that conservation planners should examine the different grazing histories of an area. Species responded differently to specific current grazing practices; thus, incentive programs that apply a diversity of approaches rather than focusing on a change such as reduced grazing intensity should be considered. Based on our findings, we suggest that determining fine-scale grazing attributes is essential for advancing grazing as a conservation strategy. © 2016 Society for Conservation Biology.

  19. The Effects of Timing of Grazing on Plant and Arthropod Communities in High-Elevation Grasslands

    Science.gov (United States)

    Davis, Stacy C.; Burkle, Laura A.; Cross, Wyatt F.; Cutting, Kyle A.

    2014-01-01

    Livestock grazing can be used as a key management tool for maintaining healthy ecosystems. However, the effectiveness of using grazing to modify habitat for species of conservation concern depends on how the grazing regime is implemented. Timing of grazing is one grazing regime component that is less understood than grazing intensity and grazer identity, but is predicted to have important implications for plant and higher trophic level responses. We experimentally assessed how timing of cattle grazing affected plant and arthropod communities in high-elevation grasslands of southwest Montana to better evaluate its use as a tool for multi-trophic level management. We manipulated timing of grazing, with one grazing treatment beginning in mid-June and the other in mid-July, in two experiments conducted in different grassland habitat types (i.e., wet meadow and upland) in 2011 and 2012. In the upland grassland experiment, we found that both early and late grazing treatments reduced forb biomass, whereas graminoid biomass was only reduced with late grazing. Grazing earlier in the growing season versus later did not result in greater recovery of graminoid or forb biomass as expected. In addition, the density of the most ubiquitous grassland arthropod order (Hemiptera) was reduced by both grazing treatments in upland grasslands. A comparison of end-of-season plant responses to grazing in upland versus wet meadow grasslands revealed that grazing reduced graminoid biomass in the wet meadow and forb biomass in the upland, irrespective of timing of grazing. Both grazing treatments also reduced end-of-season total arthropod and Hemiptera densities and Hemiptera biomass in both grassland habitat types. Our results indicate that both early and late season herbivory affect many plant and arthropod characteristics in a similar manner, but grazing earlier may negatively impact species of conservation concern requiring forage earlier in the growing season. PMID:25338008

  20. Social recognition is context dependent in single male prairie voles

    Science.gov (United States)

    Zheng, Da-Jiang; Foley, Lauren; Rehman, Asad; Ophir, Alexander G.

    2013-01-01

    Single males might benefit from knowing the identity of neighbouring males when establishing and defending boundaries. Similarly, males should discriminate between individual females if this leads to more reproductive opportunities. Contextual social cues may alter the value of learning identity. Knowing the identity of competitors that intrude into an animal’s territory may be more salient than knowing the identity of individuals on whose territory an animal is trespassing. Hence, social and environmental context could affect social recognition in many ways. Here we test social recognition of socially monogamous single male prairie voles, Microtus ochrogaster. In experiment 1 we tested recognition of male or female conspecifics and found that males discriminated between different males but not between different females. In experiment 2 we asked whether recognition of males is influenced when males are tested in their own cage (familiar), in a clean cage (neutral) or in the home cage of another male (unfamiliar). Although focal males discriminated between male conspecifics in all three contexts, individual variation in recognition was lower when males were tested in their home cage (in the presence of familiar social cues) compared to when the context lacked social cues (neutral). Experiment 1 indicates that selective pressures may have operated to enhance male territorial behaviour and indiscriminate mate selection. Experiment 2 suggests that the presence of a conspecific cue heightens social recognition and that home-field advantages might extend to social cognition. Taken together, our results indicate social recognition depends on the social and possibly territorial context. PMID:24273328

  1. Climate impacts on the hydrology of prairie wetlands

    International Nuclear Information System (INIS)

    Woo, Mingko; Rowsell, R.D.

    1991-01-01

    A study was carried out in the St. Denis National Wildlife Area, 45 km east of Saskatoon, to observe the hydrological processes and the temporal and spatial variability of slough responses to climate. One slough was instrumented for detailed study, showing that the high water level in spring was supported by snowmelt. In summer, rainfall was the major source of water supply, but was exceeded by losses to evaporation and groundwater recharge, leading to a decline of the water table and complete drying by June 13th. The duration that water remains in sloughs varies temporally and spatially. Ephemeral sloughs, deriving water mainly from snowmelt, tend to occupy higher ground, temporary sloughs rely on precipitation and surface runoff, and may receive groundwater discharge during wetter years. Permanent sloughs often occupy lower areas, receiving water from precipitation, lateral runoff, and groundwater discharge which buffers them from year to year fluctuations in precipitation. Tree ring analyses showed that meltwater is the major factor influencing tree growth, correlating the spatial variability of slough inundation to the temporal variability of winter snowfall. A study of slough hydrology is important to the understanding of the responses of Prairie wetlands to climatic variability and change. 17 refs., 2 figs

  2. Managing Water-Food-Energy Futures in the Canadian Prairies

    Science.gov (United States)

    Wheater, H. S.; Hassanzadeh, E.; Nazemi, A.; Elshorbagy, A. A.

    2016-12-01

    The water-food-energy nexus is a convenient phrase to highlight competing societal uses for water and the need for cross-sectoral policy integration, but this can lead to oversimplification of the multiple dimensions of water (and energy) management. In practice, water managers must balance (and prioritize) demands for water for many uses, including environmental flows, and reservoir operation often involves managing conflicting demands, for example to maximize retention for supply, reduce storage to facilitate flood control, and constrain water levels and releases for habitat protection. Agriculture and water quality are also inextricably linked: irrigated agriculture requires appropriate water quality for product quality and certification, but agriculture can be a major source of nutrient pollution, with impacts on human and ecosystem health, drinking water treatment and amenity. And energy-water interactions include energy production (hydropower and cooling water for thermal power generation) and energy consumption (e.g. for pumping and water and wastewater treatment). These dependencies are illustrated for the Canadian prairies, and a risk-based approach to the management of climate change is presented. Trade-offs between economic benefits of hydropower and irrigation are illustrated for alternative climate futures, including implications for freshwater habitats. The results illustrate that inter-sector interactions vary as a function of climate and its variability, and that there is a need for policy to manage inter-sector allocations as a function of economic risk.

  3. Assessing diversity of prairie plants using remote sensing

    Science.gov (United States)

    Gamon, J. A.; Wang, R.

    2017-12-01

    Biodiversity loss endangers ecosystem services and is considered as a global change that may generate unacceptable environmental consequences for the Earth system. Global biodiversity observations are needed to provide a better understanding of biodiversity - ecosystem services relationships and to provide a stronger foundation for conserving the Earth's biodiversity. While remote sensing metrics have been applied to estimate α biodiversity directly through optical diversity, a better understanding of the mechanisms behind the optical diversity-biodiversity relationship is needed. We designed a series of experiments at Cedar Creek Ecosystem Science Reserve, MN, to investigate the scale dependence of optical diversity and explore how species richness, evenness, and composition affect optical diversity. We collected hyperspectral reflectance of 16 prairie species using both a full-range field spectrometer fitted with a leaf clip, and an imaging spectrometer carried by a tram system to simulate plot-level images with different species richness, evenness, and composition. Two indicators of spectral diversity were explored: the coefficient of variation (CV) of spectral reflectance in space, and spectral classification using a Partial Least Squares Discriminant Analysis (PLS-DA). Our results showed that sampling methods (leaf clip-derived data vs. image-derived data) affected the optical diversity estimation. Both optical diversity indices were affected by species richness and evenness (Pguide regional studies of biodiversity estimation using high spatial and spectral resolution remote sensing.

  4. Homicide in the Canadian Prairies: elderly and nonelderly killings.

    Science.gov (United States)

    Ahmed, A G; Menzies, Robin P D

    2002-11-01

    To examine the psychosocial and clinical characteristics of male perpetrators of elderly and nonelderly homicides in the Canadian Prairies. We examined data drawn from a study of 901 adult homicide offenders who were incarcerated or on parole between 1988 and 1992 in Alberta, Saskatchewan, and Manitoba. Of those studied, 67 men were convicted of homicide involving 79 elderly victims, and 671 were convicted of homicide involving 675 nonelderly victims. Most perpetrators were single and engaged in irregular patterns of employment at the time of their index offence. Fourteen (20.8%) offenders with elderly victims had a history of psychiatric treatment, compared with 98 (14.6%) offenders with nonelderly victims; however, this difference was not statistically significant. Approximately 30% of both groups were diagnosed with personality disorders. A comparison of the index- offence characteristics showed no significant differences between the 2 groups. Our findings suggest that elderly individuals are more likely to be killed in their own homes by strangers. Social isolation appears to be a significant risk factor in cases of elderly homicide.

  5. Morphogenesis in guinea grass pastures under rotational grazing strategies

    Directory of Open Access Journals (Sweden)

    Denise Baptaglin Montagner

    2012-04-01

    Full Text Available This study was conducted in order to evaluate the morphogenetic and structural characteristics of guinea grass cv. Mombasa under three post-grazing heights (intense - 30 cm, lenient - 50 cm and variable - 50 in spring-summer and 30 cm in autumn-winter when sward light interception reached 95% during regrowth. Post-grazing heights were allocated to experimental units (0.25 ha in a completely randomized block design with three replications. Post-grazing heights affected only leaf elongation rate and the number of live leaves. Pastures managed with variable post-grazing height showed higher leaf elongation rate in the summer of 2007. This management strategy also resulted in a higher number of live leaves. During the spring of 2006, plants showed lower leaf elongation rate, leaf appearance rate and number of live leaves, and greater phyllochron and leaf lifespan. In contrast, during the summer of 2007, the leaf appearance rate, leaf elongation rate, number of live leaves, and final leaf length were greater while phyllochron, stem elongation rate, and leaf senescence rate were lower. The management of the guinea grass cv. Mombasa with intense or variable post-grazing height throughout the year seems to represent an interesting management target, in terms of leaf appearance rate and number of live leaves.

  6. Proceedings of the symposium on the management of prairie dog complexes for the reintroduction of the black-footed ferret

    Science.gov (United States)

    Oldemeyer, John L.; Biggins, Dean E.; Miller, Brian J.; Crete, Ronald

    1993-01-01

    The workshop featured a review of current knowledge in the biology of prairie dogs in the context of managing black-footed ferret habitat. The review addressed two main components. The first consisted of a series of papers on prairie dog habitat and biology. The second component of the workshop was a summary of the participants' discussion about managing prairie dog complexes. This discussion was based on the previously identified papers and profited from the participants' expertise on the ecology of black-footed ferrets and prairie dogs. The report provides current and comprehensive information about management of habitat for prairie dogs and black-footed ferrets and is a useful guide for agencies and individuals that manage black-footed ferrets.

  7. Mesozooplankton production, grazing and respiration in the Bay of Bengal: Implications for net heterotrophy

    Science.gov (United States)

    Fernandes, Veronica; Ramaiah, N.

    2016-03-01

    Mesozooplankton samples were collected from the mixed layer along a central (along 88°E) and a western transect in the Bay of Bengal during four seasons covered between 2001 and 2006 in order to investigate spatio-temporal variability in their biomass. At these stations, grazing and respiration rates were measured from live zooplankton hauled in from the surface during December 2005. Akin to the mesozooplankton "paradox" in the central and eastern Arabian Sea, biomass in the mixed layer was more or less invariant in the central and western Bay of Bengal, even as the chl a showed marginal temporal variation. By empirical equation, the mesozooplankton production rate calculated to be 70-246 mg C m- 2 d- 1 is on par with the Arabian Sea. Contrary to the conventional belief, mesozooplankton grazing impact was up to 83% on primary production (PP). Low PP coupled with very high zooplankton production (70% of PP) along with abundant bacterial production (50% of the PP; Ramaiah et al., 2009) is likely to render the Bay of Bengal net heterotrophic, especially during the spring intermonsoon. Greater estimates of fecal pellet-carbon egestion by mesozooplankton compared to the average particulate organic carbon flux in sediment traps, implies that much of the matter is recycled by heterotrophic communities in the mixed layer facilitating nutrient regeneration for phytoplankton growth. We also calculated that over a third of the primary production is channelized for basin-wide zooplankton respiration that accounts for 52 Mt C annually. In the current scenario of global warming, if low (primary) productive warm pools like the Bay of Bengal continue to be net heterotrophic, negative implications like enhanced emission of CO2 to the atmosphere, increased particulate flux to the deeper waters and greater utilization of dissolved oxygen resulting in expansion of the existing oxygen minimum zone are imminent.

  8. Conservation Reserve Program mitigates grassland loss in the lesser prairie-chicken range of Kansas

    Science.gov (United States)

    Haukos, David A.; Spencer, David; Hagen, Christian A.; Daniels, Melinda D.; Goodin, Doug

    2017-01-01

    Since the beginning of the 20th century, the overall occupied range of the lesser prairie-chicken (Tympanuchus pallidicinctus) has declined by 84% commensurate with population trends. Much of this decline has been attributed to the loss and fragmentation of native grasslands throughout the lesser prairie-chicken range. However, quantification of changes in land cover in the distribution of the lesser prairie-chicken is lacking. Our objectives were to (1) document changes in the areal extent and connectivity of grasslands in the identified lesser prairie-chicken range in Kansas, USA, (>60% of extant lesser prairie-chicken population) from the 1950s to 2013 using remotely sensed data and (2) assess the potential of the Conservation Reserve Program (U.S. Department of Agriculture Program converting cropland to permanent cover; CRP) to mitigate grassland loss. Digital land cover maps were generated on a decadal time step through spectral classification of LANDSAT images and visual analysis of aerial photographs (1950s and 1960s). Landscape composition and configuration were assessed using FRAGSTATS to compute a variety of landscape metrics measuring changes in the amount of grassland present as well as changes in the size and configuration of grassland patches. With the exception of a single regional portion of the range, nearly all of the grassland converted to cropland in the lesser prairie-chicken range of Kansas occurred prior to the 1950s. Prior to the implementation of CRP, the amount of grassland decreased 3.6% between the 1950s and 1985 from 18,455 km2 to 17,788 km2. Since 1985, the overall amount of grassland in the lesser prairie-chicken range has increased 11.9% to 19,898 km2 due to implementation of CRP, although the area of grassland decreased between 1994 and 2013 as CRP contracts were not renewed by landowners. Since 1986 grassland in Kansas became more connected and less fragmented in response to the CRP. While the CRP has been successful in

  9. Conservation Reserve Program mitigates grassland loss in the lesser prairie-chicken range of Kansas

    Directory of Open Access Journals (Sweden)

    David Spencer

    2017-01-01

    Full Text Available Since the beginning of the 20th century, the overall occupied range of the lesser prairie-chicken (Tympanuchus pallidicinctus has declined by 84% commensurate with population trends. Much of this decline has been attributed to the loss and fragmentation of native grasslands throughout the lesser prairie-chicken range. However, quantification of changes in land cover in the distribution of the lesser prairie-chicken is lacking. Our objectives were to (1 document changes in the areal extent and connectivity of grasslands in the identified lesser prairie-chicken range in Kansas, USA, (>60% of extant lesser prairie-chicken population from the 1950s to 2013 using remotely sensed data and (2 assess the potential of the Conservation Reserve Program (U.S. Department of Agriculture Program converting cropland to permanent cover; CRP to mitigate grassland loss. Digital land cover maps were generated on a decadal time step through spectral classification of LANDSAT images and visual analysis of aerial photographs (1950s and 1960s. Landscape composition and configuration were assessed using FRAGSTATS to compute a variety of landscape metrics measuring changes in the amount of grassland present as well as changes in the size and configuration of grassland patches. With the exception of a single regional portion of the range, nearly all of the grassland converted to cropland in the lesser prairie-chicken range of Kansas occurred prior to the 1950s. Prior to the implementation of CRP, the amount of grassland decreased 3.6% between the 1950s and 1985 from 18,455 km2 to 17,788 km2. Since 1985, the overall amount of grassland in the lesser prairie-chicken range has increased 11.9% to 19,898 km2 due to implementation of CRP, although the area of grassland decreased between 1994 and 2013 as CRP contracts were not renewed by landowners. Since 1986 grassland in Kansas became more connected and less fragmented in response to the CRP. While the CRP has been successful

  10. Social transfer of alcohol withdrawal-induced hyperalgesia in female prairie voles.

    Science.gov (United States)

    Walcott, Andre T; Smith, Monique L; Loftis, Jennifer M; Ryabinin, Andrey E

    2018-03-27

    The expression of pain serves as a way for animals to communicate potential dangers to nearby conspecifics. Recent research demonstrated that mice undergoing alcohol or morphine withdrawal, or inflammation, could socially communicate their hyperalgesia to nearby mice. However, it is unknown whether such social transfer of hyperalgesia can be observed in other species of rodents. Therefore, the present study investigated if the social transfer of hyperalgesia occurs in the highly social prairie vole (Microtus ochrogaster). We observe that adult female prairie voles undergoing withdrawal from voluntary two-bottle choice alcohol drinking display an increase in nociception. This alcohol withdrawal-induced hypersensitiity is socially transferred to female siblings within the same cage and female strangers housed in separate cages within the same room. These experiments reveal that the social transfer of pain phenomenon is not specific to inbred mouse strains and that prairie voles display alcohol withdrawal and social transfer-induced hyperalgesia.

  11. The effect of listing the lesser prairie chicken as a threatened species on rural property values.

    Science.gov (United States)

    Wietelman, Derek C; Melstrom, Richard T

    2017-04-15

    This paper estimates the effect of Endangered Species Act protections for the lesser prairie chicken (Tympanuchus pallidicinctus) on rural property values in Oklahoma. The political and legal controversy surrounding the listing of imperiled species raises questions about the development restrictions and opportunity costs the Endangered Species Act imposes on private landowners. Examining parcel-level sales data before and after the listing of the endemic lesser prairie chicken, we employ difference-in-differences (DD) regression to measure the welfare costs of these restrictions. While our basic DD regression provides evidence the listing was associated with a drop in property values, this finding does not hold up in models that control for latent county and year effects. The lack of a significant price effect is confirmed by several robustness checks. Thus, the local economic costs of listing the lesser prairie chicken under the Endangered Species Act appear to have been small. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Initial stages of the ion beam mixing process

    International Nuclear Information System (INIS)

    Traverse, A.; Le Boite, M.G.; Nevot, L.; Pardo, B.; Corno, J.

    1987-01-01

    The grazing x-ray reflectometry technique, performed on irradiated periodic multilayers, was used to study the early stages of the ion beam mixing process. We present our first results, obtained on NiAu samples irradiated with He ions. The experimental fluence dependence of the effective diffusion coefficient is in good agreement with a calculation based on a purely ballistic process

  13. Magnetic minerals in soils across the forest-prairie ecotone in NW Minnesota

    Science.gov (United States)

    Maxbauer, D.; Feinberg, J. M.; Fox, D. L.; Nater, E. A.

    2016-12-01

    Soil pedogenesis results in a complex assemblage of iron oxide minerals that can be disentangled successfully using sensitive magnetic techniques to better delineate specific soil processes. Here, we evaluate the variability in soil processes within forest, prairie, and transitional soils along an 11 km transect of anthropogenically unaltered soils that span the forest-to-prairie ecotone in NW Minnesota. All soils in this study developed on relatively uniform topography, similar glacial till parent material, under a uniform climate, and presumably over similar time intervals. The forest-to-prairie transition zone in this region is controlled by naturally occurring fires, affording the opportunity to evaluate differences in soil processes related to vegetation (forest versus prairie) and burning (prairie and transitional soils). Results suggest that the pedeogenic fraction of magnetite/maghemite in soils is similar in all specimens and is independent of soil type, vegetation, and any effects of burning. Magnetically enhanced horizons have 45% of remanence held by a low-coercivity pedogenic component (likely magnetite/maghemite) regardless of vegetation cover and soil type. Enhancement ratios for magnetic susceptibility and low-field remanences, often used as indicators of pedogenic magnetic minerals, are more variable but remain statistically equivalent across the transect. These results support the hypothesis that pedogenic magnetic minerals in soils mostly reflect ambient climatic conditions regardless of the variability in soil processes related to vegetation and soil type. The non-pedogenic magnetic mineral assemblage shows clear distinctions between the forest, prairie, and transitional soils in hysteresis properties (remanence and coercivity ratios; Mr/Ms and Bc/Bcr, respectively), suggesting that variable processes in these settings influence the local magnetic mineral assemblage, and that it may be possible to use magnetic minerals in paleosols to constrain

  14. Landscape composition creates a threshold influencing Lesser Prairie-Chicken population resilience to extreme drought

    Science.gov (United States)

    Ross, Beth E.; Haukos, David A.; Hagen, Christian A.; Pitman, James C.

    2016-01-01

    Habitat loss and degradation compound the effects of climate change on wildlife, yet responses to climate and land cover change are often quantified independently. The interaction between climate and land cover change could be intensified in the Great Plains region where grasslands are being converted to row-crop agriculture concurrent with increased frequency of extreme drought events. We quantified the combined effects of land cover and climate change on a species of conservation concern in the Great Plains, the Lesser Prairie-Chicken (Tympanuchus pallidicinctus  ). We combined extreme drought events and land cover change with lek count surveys in a Bayesian hierarchical model to quantify changes in abundance of male Lesser Prairie-Chickens from 1978 to 2014 in Kansas, the core of their species range. Our estimates of abundance indicate a gradually decreasing population through 2010 corresponding to drought events and reduced grassland areas. Decreases in Lesser Prairie-Chicken abundance were greatest in areas with increasing row-crop to grassland land cover ratio during extreme drought events, and decreased grassland reduces the resilience of Lesser Prairie-Chicken populations to extreme drought events. A threshold exists for Lesser Prairie-Chickens in response to the gradient of cropland:grassland land cover. When moving across the gradient of grassland to cropland, abundance initially increased in response to more cropland on the landscape, but declined in response to more cropland after the threshold (δ=0.096, or 9.6% cropland). Preservation of intact grasslands and continued implementation of initiatives to revert cropland to grassland should increase Lesser Prairie-Chicken resilience to extreme drought events due to climate change.

  15. Horse grazing systems: understory biomass and plant biodiversity of a Pinus radiata stand

    Directory of Open Access Journals (Sweden)

    Antonio Rigueiro-Rodríguez

    2012-02-01

    Full Text Available Horse grazing systems may affect productivity and biodiversity of understory developed under Pinus radiata D. Don silvopastoral systems, while acting as a tool to reduce the risk of fire. This study compared continuous and rotational grazing systems effect upon biomass, fractions of stem, sprouts, leaves and woody parts of Ulex europaeus L. and alpha (Species Richness, Shannon-Wiener and beta (Jaccard and Magurran biodiversity for a period of four years in a P. radiata silvopastoral system. The experiment consisted of a randomized block design of two treatments (continuous and rotational grazing. Biomass, and species abundances were measured - biodiversity metrics were calculated based on these results for a two years of grazing and two years of post-grazing periods. Both continuous and rotational grazing systems were useful tools for reducing biomass and, therefore, fire risk. The rotational grazing system caused damage to the U. europaeus shrub, limiting its recovery once grazing was stopped. However, the more intensive grazing of U. europaeus plants under rotational had a positive effect on both alpha and beta biodiversity indexes due to the low capacity of food selection in the whole plot rather than continuous grazing systems. Biomass was not affected by the grazing system; however the rotational grazing system is more appropriate to reduce U. europaeus biomass and therefore forest fire risk at a long term and to enhance pasture biodiversity than the continuous grazing system.

  16. Cattle grazing and its long-term effects on sedge meadows

    Science.gov (United States)

    Middleton, Beth

    2004-01-01

    Most people think that wetlands are temporary, that they fill in by natural processes, and eventually become dry land. Some of these outdated ideas have come from the way that this subject has been covered in introductory textbooks in schools (Gibson, 1996). From these texts, we learned incorrectly that over time a lake fills with sediment or organic matter to become a wetland, which dries out to support shrubs and trees, and eventually it is no longer a wetland (Middleton, 1999; Middleton and others, 2004). These old ideas of how vegetation changes (succession) are no longer accepted. Wetland succession should be thought of as a cycle, with natural disturbance driving the changes, depending on the needs of the species. Succession is not something that changes a wetland into something that is not a wetland (Egler, 1978; van der Valk, 1981; Middleton and others, 1991; Klinger, 1996; Middleton, 1999).As an example of how disturbance changes wetlands, I have studied sedge meadows that have become invaded by shrubs after cattle (Bos sp.) have grazed them, in the Lodi Marsh State Natural Area, Wisconsin. Cattle disturbances allowed shrubs to invade sedge meadows, but the cattle also grazed on the shrubs, which kept them small. After the cows were removed, the plant species changed in the sedge meadow from the original sedges (fig. 1), to sedges mixed with growing small shrubs, and eventually to tall shrubs with very small amounts of sedge, called “shrub carr” (Middleton, 2002a). Even though there has been a succession of plant types, the meadows, which began as wetlands, have remained wetlands. The settlers originally found the sedge meadows to be open “sedge” lands and not shrubby. The settlers cut the sedges by hand to feed the cattle. Whitetailed deer (Odocoileus virginianus), though probably not bison (Bison bison), grazed these sedge meadows (Middleton 2002a).Subsequent studies have explored methods to control invasive shrubs to restore the biodiversity of

  17. Impact of Prairie Cover on Hydraulic Conductivity and Storm Water Runoff

    Science.gov (United States)

    Herkes, D. M. G.; Gori, A.; Juan, A.

    2017-12-01

    Houston has long struggled to find effective solutions to its historic flooding problems. Conventional strategies have revolved around constructing hard infrastructure such as levees or regional detention ponds to reduce flood impacts. However, there has been a recent shift to explore the implementation of nature-based solutions in reducing flood impacts. This is due to the price of structural mechanisms, as well as their failure to adequately protect areas from flooding during the latest flood events. One alternative could be utilizing the natural water retention abilities of native Texas prairies. This study examines the effect of Texas prairie areas in increasing soil infiltration capacities, thereby increasing floodwater storage and reducing surface runoff. For this purpose, an infiltration study of 15 sites was conducted on lands owned by the Katy Prairie Conservancy within Cypress Creek watershed. Located in Northwest Houston, it is an area which had been heavily impacted by recent flood events. Each sampling site was selected to represent a particular land cover or vegetation type, ranging from developed open space to native prairies. Field test results are then compared to literature values of soil infiltration capacity in order to determine the infiltration benefit of each vegetation type. Test results show that certain vegetation, especially prairies, significantly increase the infiltration capacity of the underlying soil. For example, the hydraulic conductivity of prairie on sandy loam soil is approximately an order of magnitude higher than that of the soil itself. Finally, a physics-based hydrologic model is utilized to evaluate the flood reduction potential of native Texas prairie. This model represents Cypress Creek watershed in gridded cell format, and allows varying hydraulic and infiltration parameters at each cell. Design storms are run to obtain flow hydrographs for selected watch points in the study area. Two scenarios are simulated and compared

  18. Field-level financial assessment of contour prairie strips for enhancement of environmental quality.

    Science.gov (United States)

    Tyndall, John C; Schulte, Lisa A; Liebman, Matthew; Helmers, Matthew

    2013-09-01

    The impacts of strategically located contour prairie strips on sediment and nutrient runoff export from watersheds maintained under an annual row crop production system have been studied at a long-term research site in central Iowa. Data from 2007 to 2011 indicate that the contour prairie strips utilized within row crop-dominated landscapes have greater than proportionate and positive effects on the functioning of biophysical systems. Crop producers and land management agencies require comprehensive information about the Best Management Practices with regard to performance efficacy, operational/management parameters, and the full range of financial parameters. Here, a farm-level financial model assesses the establishment, management, and opportunity costs of contour prairie strips within cropped fields. Annualized, depending on variable opportunity costs the 15-year present value cost of utilizing contour prairie strips ranges from $590 to $865 ha(-1) year(-1) ($240-$350 ac(-1) year(-1)). Expressed in the context of "treatment area" (e.g., in this study 1 ha of prairie treats 10 ha of crops), the costs of contour prairie strips can also be viewed as $59 to about $87 per treated hectare ($24-$35 ac(-1)). If prairie strips were under a 15-year CRP contract, total per acre cost to farmers would be reduced by over 85 %. Based on sediment, phosphorus, and nitrogen export data from the related field studies and across low, medium, and high land rent scenarios, a megagram (Mg) of soil retained within the watershed costs between $7.79 and $11.46 mg(-1), phosphorus retained costs between $6.97 and $10.25 kg(-1), and nitrogen retained costs between $1.59 and $2.34 kg(-1). Based on overall project results, contour prairie strips may well become one of the key conservation practices used to sustain US Corn Belt agriculture in the decades to come.

  19. Graphite irradiated by swift heavy ions under grazing incidence

    CERN Document Server

    Liu, J; Müller, C; Neumann, R

    2002-01-01

    Highly oriented pyrolytic graphite is irradiated with various heavy projectiles (Ne, Ni, Zn, Xe and U) in the MeV to GeV energy range under different oblique angles of incidence. Using scanning tunneling microscopy, the impact zones are imaged as hillocks protruding from the surface. The diameter of surface-grazing tracks varies between 3 nm (Ne) and 6 nm (U), which is about twice as large as under normal beam incidence. Exclusively for U and Xe projectiles, grazing tracks exhibit long comet-like tails consisting of successive little bumps indicating that the damage along the ion path is discontinuous even for highest electronic stopping powers.

  20. 1000 years of sustainable grazing in Nordic conditions?

    DEFF Research Database (Denmark)

    Brandt, Jesper

    landscapes at different spatial levels. Information on much of this sort of regulation has however been lost through modern times, tended to prefer modern (nature) scientific methods primarily developed as general (meaning not spatially contextual) recommendations for raising productivity. During the later...... years this modern tradition has also been preferred by investigations to find solutions for non-sustainable types of land use in grazing systems. However, much sustainability-relevant wisdom has been accumulated in historical grazing-systems that should be included in the repertoire of knowledge...

  1. X-ray grazing incidence diffraction from multilayers

    Energy Technology Data Exchange (ETDEWEB)

    Tixier, S.; Boeni, P.; Swygenhoven, H. van; Horisberger, M. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1997-09-01

    Grazing incidence scattering geometries using synchrotron radiation have been applied in order to characterise the roughness profiles and the structural coherence of multilayers. The lateral correlation length of the roughness profiles was evaluated using diffuse reflectivity in the `out of plane` geometry. This type of measurement is the only diffuse reflectivity technique allowing large lateral momentum transfer. It is typically suitable for correlation lengths smaller than 1000 A. The lateral structural coherence length of Ni{sub 3}Al/Ni multilayers as a function of the layer thickness was obtained by grazing incidence diffraction (GID). 3 figs., 1 ref.

  2. Effect of grazing on the cow welfare of dairy herds evaluated by a multidimensional welfare index

    DEFF Research Database (Denmark)

    Burow, E.; Rousing, T.; Thomsen, P. T.

    2013-01-01

    Structural development in the prime sector has led to increasing herd sizes and new barn systems, followed by less summer grazing for dairy cows in Denmark. Effects of grazing on single welfare measures in dairy cows - for example, the presence of integument alterations or mortality - have been......) inspired multidimensional dairy cow welfare assessment protocol, the within-herd effect of summer grazing compared with winter barn housing in Danish dairy herds with cubicle free-stall systems for the lactating cows. Our hypothesis was that cow welfare in dairy herds was better during summer grazing than...... out to be more beneficial than few daily grazing hours (range average above 9 to 21 h) for the welfare of the dairy herds. In conclusion, this study reports a positive within-herd effect of summer grazing on dairy cow welfare, where many daily grazing hours were more beneficial than few daily grazing...

  3. Herbage availability €rs a stress factor on grazed Coastcross II ...

    African Journals Online (AJOL)

    ) relationships for Coastcross ll Bermuda grass grazed for four consecutive summer periods by young growing beef cattle. Stocking rate affected the daily. LWG/animal through its influence on herbage availability. Rota- tional grazing showed a ...

  4. The prevalence of serum antibodies to tick-borne infections in Mbale District, Uganda: The effect of agro-ecological zone, grazing management and age of cattle

    Directory of Open Access Journals (Sweden)

    C. Rubaire-Akiiki

    2004-03-01

    Full Text Available Between August and October 2000, a cross-sectional study was conducted in smallholder dairy farms in Mbale District, Uganda to assess the prevalence of ticks and tick-borne diseases under different grazing systems and agro-ecological zones and understand the circumstances under which farmers operated. A questionnaire was administered to obtain information on dairy farm circumstances and practices. A total of 102 farms were visited and sera and ticks were collected from 478 animals. Sero-prevalence of tick-borne diseases was determined using an enzyme-linked immunoassay. Acaricides were used indiscriminately but the intensity of their use varied with the grazing system and zone. Cattle from different farms mixed for various reasons. During the dry seasons farmers have to get additional fodder from outside their farms that can result in importation of ticks. The prevalence of ticks and serum antibodies to tick-borne infections differed across the grazing systems and zones. The highest serum antibody prevalence (>60% was recorded in the lowland zone under the free range and tethering grazing systems. The lowest tick challenge and serum antibody levels (<50% were recorded in the midland and upland zones under a zero-grazing system. These findings suggest that endemic stability to East Coast Fever, babesiosis and anaplasmosis is most likely to have existed in the lowland zone, particularly, under the tethering and free-range grazing systems. Also, endemic stability for babesiosis existed in the upland zones. Endemic instability for East Coast Fever existed in the midland and upland zones. These structured observational studies are instrumental in planning of control strategies for ticks and tick borne diseases since production systems and the cattle population at high risk of the diseases in the district have been identified.

  5. Metabarcoding and metabolome analyses of copepod grazing reveal feeding preference and linkage to metabolite classes in dynamic microbial plankton communities.

    Science.gov (United States)

    Ray, Jessica L; Althammer, Julia; Skaar, Katrine S; Simonelli, Paolo; Larsen, Aud; Stoecker, Diane; Sazhin, Andrey; Ijaz, Umer Z; Quince, Christopher; Nejstgaard, Jens C; Frischer, Marc; Pohnert, Georg; Troedsson, Christofer

    2016-11-01

    In order to characterize copepod feeding in relation to microbial plankton community dynamics, we combined metabarcoding and metabolome analyses during a 22-day seawater mesocosm experiment. Nutrient amendment of mesocosms promoted the development of haptophyte (Phaeocystis pouchetii)- and diatom (Skeletonema marinoi)-dominated plankton communities in mesocosms, in which Calanus sp. copepods were incubated for 24 h in flow-through chambers to allow access to prey particles (<500 μm). Copepods and mesocosm water sampled six times spanning the experiment were analysed using metabarcoding, while intracellular metabolite profiles of mesocosm plankton communities were generated for all experimental days. Taxon-specific metabarcoding ratios (ratio of consumed prey to available prey in the surrounding seawater) revealed diverse and dynamic copepod feeding selection, with positive selection on large diatoms, heterotrophic nanoflagellates and fungi, while smaller phytoplankton, including P. pouchetii, were passively consumed or even negatively selected according to our indicator. Our analysis of the relationship between Calanus grazing ratios and intracellular metabolite profiles indicates the importance of carbohydrates and lipids in plankton succession and copepod-prey interactions. This molecular characterization of Calanus sp. grazing therefore provides new evidence for selective feeding in mixed plankton assemblages and corroborates previous findings that copepod grazing may be coupled to the developmental and metabolic stage of the entire prey community rather than to individual prey abundances. © 2016 John Wiley & Sons Ltd.

  6. Ecological consequences of shifting the timing of burning tallgrass prairie.

    Directory of Open Access Journals (Sweden)

    E Gene Towne

    Full Text Available In the Kansas Flint Hills, grassland burning is conducted during a relatively narrow window because management recommendations for the past 40 years have been to burn only in late spring. Widespread prescribed burning within this restricted time frame frequently creates smoke management issues downwind. A potential remedy for the concentrated smoke production in late spring is to expand burning to times earlier in the year. Yet, previous research suggested that burning in winter or early spring reduces plant productivity and cattle weight gain while increasing the proportion of undesirable plant species. In order to better understand the ecological consequences of burning at different times of the year, plant production and species abundance were measured for 20 years on ungrazed watersheds burned annually in autumn, winter, or spring. We found that there were no significant differences in total grass production among the burns on either upland or lowland topographic positions, although spring burned watersheds had higher grass culm production and lower forb biomass than autumn and winter burned watersheds. Burning in autumn or winter broadened the window of grass productivity response to precipitation, which reduces susceptibility to mid-season drought. Burning in autumn or winter also increased the phenological range of species by promoting cool-season graminoids without a concomitant decrease in warm-season grasses, potentially widening the seasonal window of high-quality forage. Incorporating autumn and winter burns into the overall portfolio of tallgrass prairie management should increase the flexibility in managing grasslands, promote biodiversity, and minimize air quality issues caused by en masse late-spring burning with little negative consequences for cattle production.

  7. Continuous Cropping and Moist Deep Convection on the Canadian Prairies

    Directory of Open Access Journals (Sweden)

    Devon E. Worth

    2012-12-01

    Full Text Available Summerfallow is cropland that is purposely kept out of production during a growing season to conserve soil moisture. On the Canadian Prairies, a trend to continuous cropping with a reduction in summerfallow began after the summerfallow area peaked in 1976. This study examined the impact of this land-use change on convective available potential energy (CAPE, a necessary but not sufficient condition for moist deep convection. All else being equal, an increase in CAPE increases the probability-of-occurrence of convective clouds and their intensity if they occur. Representative Bowen ratios for the Black, Dark Brown, and Brown soil zones were determined for 1976: the maximum summerfallow year, 2001: our baseline year, and 20xx: a hypothetical year with the maximum-possible annual crop area. Average mid-growing-season Bowen ratios and noon solar radiation were used to estimate the reduction in the lifted index (LI from land-use weighted evapotranspiration in each study year. LI is an index of CAPE, and a reduction in LI indicates an increase in CAPE. The largest reductions in LI were found for the Black soil zone. They were −1.61 ± 0.18, −1.77 ± 0.14 and −1.89 ± 0.16 in 1976, 2001 and 20xx, respectively. These results suggest that, all else being equal, the probability-of-occurrence of moist deep convection in the Black soil zone was lower in 1976 than in the base year 2001, and it will be higher in 20xx when the annual crop area reaches a maximum. The trend to continuous cropping had less impact in the drier Dark Brown and Brown soil zones.

  8. The scale dependence of optical diversity in a prairie ecosystem

    Science.gov (United States)

    Gamon, J. A.; Wang, R.; Stilwell, A.; Zygielbaum, A. I.; Cavender-Bares, J.; Townsend, P. A.

    2015-12-01

    Biodiversity loss, one of the most crucial challenges of our time, endangers ecosystem services that maintain human wellbeing. Traditional methods of measuring biodiversity require extensive and costly field sampling by biologists with extensive experience in species identification. Remote sensing can be used for such assessment based upon patterns of optical variation. This provides efficient and cost-effective means to determine ecosystem diversity at different scales and over large areas. Sampling scale has been described as a "fundamental conceptual problem" in ecology, and is an important practical consideration in both remote sensing and traditional biodiversity studies. On the one hand, with decreasing spatial and spectral resolution, the differences among different optical types may become weak or even disappear. Alternately, high spatial and/or spectral resolution may introduce redundant or contradictory information. For example, at high resolution, the variation within optical types (e.g., between leaves on a single plant canopy) may add complexity unrelated to specie richness. We studied the scale-dependence of optical diversity in a prairie ecosystem at Cedar Creek Ecosystem Science Reserve, Minnesota, USA using a variety of spectrometers from several platforms on the ground and in the air. Using the coefficient of variation (CV) of spectra as an indicator of optical diversity, we found that high richness plots generally have a higher coefficient of variation. High resolution imaging spectrometer data (1 mm pixels) showed the highest sensitivity to richness level. With decreasing spatial resolution, the difference in CV between richness levels decreased, but remained significant. These findings can be used to guide airborne studies of biodiversity and develop more effective large-scale biodiversity sampling methods.

  9. Impact of Graze-­‐Out in Hard Red Winter Wheat Production

    OpenAIRE

    Neupane, Diwash; Moss, Charles B.

    2014-01-01

    We investigate the relationship between wheat graze-­‐out and cattle-­‐wheat price ratio and moisture level and examine the impact of graze-­‐out on wheat yield in major wheat-­‐producing states in US. Results indicate that cattle-­‐wheat price ratio and moisture level affect farmers’ graze out decision and graze-­‐out have significant impact on wheat yield.

  10. Fall-grown oat to extend the fall grazing season for replacement dairy heifers.

    Science.gov (United States)

    Coblentz, W K; Brink, G E; Hoffman, P C; Esser, N M; Bertram, M G

    2014-03-01

    Our objective was to assess the pasture productivity and forage characteristics of 2 fall-grown oat (Avena sativa L.) cultivars, specifically for extending the grazing season and reducing reliance on harvested forages by replacement dairy heifers. A total of 160 gravid Holstein heifers (80 heifers/yr) were stratified by weight, and assigned to 1 of 10 identical research pens (8 heifers/pen). Initial body weights were 480 ± 43.5 kg in 2011 and 509 ± 39.4 kg in 2012. During both years of the trial, four 1.0-ha pasture replicates were seeded in August with Ogle oat (Schumitsch Seed Inc., Antigo, WI), and 4 separate, but similarly configured, pasture replicates were seeded with Forage Plus oat (Kratz Farms, Slinger, WI). Heifer groups were maintained as units, assigned to specific pastures, and then allowed to graze fall-oat pastures for 6h daily before returning to the barn, where they were offered a forage-based basal total mixed ration. Two heifer groups were retained in confinement (without grazing) as controls and offered the identical total mixed ration as pasture groups. During 2011, available forage mass increased with strong linear and quadratic effects for both cultivars, peaking at almost 9 Mg/ha on October 31. In contrast, forage mass was not affected by evaluation date in 2012, remaining ≤ 2,639 kg/ha across all dates because of droughty climatic conditions. During 2012, Ogle exhibited greater forage mass than Forage Plus across all sampling dates (2,678 vs. 1,856 kg/ha), largely because of its more rapid maturation rate and greater canopy height. Estimates of energy density for oat forage ranged from 59.6 to 69.1% during 2011, and ranged narrowly from 68.4 to 70.4% during 2012. For 2011, responses for both cultivars had strong quadratic character, in which the most energy-dense forages occurred in mid November, largely due to accumulation of water-soluble carbohydrates that reached maximum concentrations of 18.2 and 15.1% for Forage Plus and Ogle

  11. Interactions among American badgers, black-footed ferrets, and prairie dogs in the grasslands of western North America

    Science.gov (United States)

    Eads, David A.; Biggins, Dean E.; Grassel, Shaun M.; Livieri, Travis M.; Licht, Daniel S.; Proulx, Gilbert; Do Linh San, Emmanuel

    2016-01-01

    American badgers (Taxidea taxus) and black-footed ferrets (Mustela nigripes) sometimes occur sympatrically within colonies of prairie dogs (Cynomys spp.) in the grasslands of western North America. From the perspective of a simplified food web, badgers are consumers of ferrets and, to a greater extent, prairie dogs; ferrets are specialized consumers of prairie dogs; and prairie dogs are consumers of vegetation. We review information on the predatory behaviours of badgers, which collectively demonstrate that badgers exhibit complex hunting strategies to improve their probability of capturing prairie dogs and, perhaps, ferrets. We also review studies of interactions between badgers and ferrets, which suggest that there is selective pressure on badgers to compete with ferrets, and pressure on ferrets to compete with and avoid badgers. We then speculate as to how prairie dogs might shape interactions between badgers and ferrets, and how badgers could spread the plague bacterium (Yersinia pestis) among prairie dog colonies. Lastly, we provide recommendations for research on this tractable system of semi-fossorial predators and prey.

  12. Methane Emission and Milk Production of Dairy Cows Grazing Pastures Rich in Legumes or Rich in Grasses in Uruguay

    Directory of Open Access Journals (Sweden)

    Roberto Gratton

    2012-06-01

    Full Text Available Understanding the impact of changing pasture composition on reducing emissions of GHGs in dairy grazing systems is an important issue to mitigate climate change. The aim of this study was to estimate daily CH4 emissions of dairy cows grazing two mixed pastures with contrasting composition of grasses and legumes: L pasture with 60% legumes on Dry Matter (DM basis and G pasture with 75% grasses on DM basis. Milk production and CH4 emissions were compared over two periods of two weeks during spring using eight lactating Holstein cows in a 2 × 2 Latin square design. Herbage organic matter intake (HOMI was estimated by chromic oxide dilution and herbage organic matter digestibility (OMD was estimated by faecal index. Methane emission was estimated by using the sulfur hexafluoride (SF6 tracer technique adapted to collect breath samples over 5-day periods. OMD (0.71 and HOMI (15.7 kg OM were not affected by pasture composition. Milk production (20.3 kg/d, milk fat yield (742 g/d and milk protein yield (667 g/d were similar for both pastures. This may be explained by the high herbage allowance (30 kg DM above 5 cm/cow which allowed the cows to graze selectively, in particular in grass sward. Similarly, methane emission expressed as absolute value (368 g/d or 516 L/d or expressed as methane yield (6.6% of Gross Energy Intake (GEI was not affected by treatments. In conclusion, at high herbage allowance, the quality of the diet selected by grazing cows did not differ between pastures rich in legumes or rich in grasses, and therefore there was no effect on milk or methane production.

  13. Methane Emission and Milk Production of Dairy Cows Grazing Pastures Rich in Legumes or Rich in Grasses in Uruguay.

    Science.gov (United States)

    Dini, Yoana; Gere, José; Briano, Carolina; Manetti, Martin; Juliarena, Paula; Picasso, Valentin; Gratton, Roberto; Astigarraga, Laura

    2012-06-08

    Understanding the impact of changing pasture composition on reducing emissions of GHGs in dairy grazing systems is an important issue to mitigate climate change. The aim of this study was to estimate daily CH₄ emissions of dairy cows grazing two mixed pastures with contrasting composition of grasses and legumes: L pasture with 60% legumes on Dry Matter (DM) basis and G pasture with 75% grasses on DM basis. Milk production and CH₄ emissions were compared over two periods of two weeks during spring using eight lactating Holstein cows in a 2 × 2 Latin square design. Herbage organic matter intake (HOMI) was estimated by chromic oxide dilution and herbage organic matter digestibility (OMD) was estimated by faecal index. Methane emission was estimated by using the sulfur hexafluoride (SF6) tracer technique adapted to collect breath samples over 5-day periods. OMD (0.71) and HOMI (15.7 kg OM) were not affected by pasture composition. Milk production (20.3 kg/d), milk fat yield (742 g/d) and milk protein yield (667 g/d) were similar for both pastures. This may be explained by the high herbage allowance (30 kg DM above 5 cm/cow) which allowed the cows to graze selectively, in particular in grass sward. Similarly, methane emission expressed as absolute value (368 g/d or 516 L/d) or expressed as methane yield (6.6% of Gross Energy Intake (GEI)) was not affected by treatments. In conclusion, at high herbage allowance, the quality of the diet selected by grazing cows did not differ between pastures rich in legumes or rich in grasses, and therefore there was no effect on milk or methane production.

  14. Influence of grazing regimes on cattle nutrition and performance and vegetation dynamics in Sahelian rangelands

    NARCIS (Netherlands)

    Ayantunde, A.A.

    1998-01-01

    In the West African Sahel, common herd management practices such as night grazing and corralling influence time available for grazing. When animals are used to deposit manure in the cropping fields, conflicts often arise between the need for animals to graze long enough for adequate feed

  15. Prescribed grazing for management of invasive vegetation in a hardwood forest understory

    Science.gov (United States)

    Ronald A. Rathfon; Songlin Fei; Jason Tower; Kenneth Andries; Michael. Neary

    2014-01-01

    Land managers considering prescribed grazing (PG) face a lack of information on animal stocking rates, timing of grazing, and duration of grazing to achieve desired conditions in natural ecosystems under invasion stress from a variety of nonnative invasive plant (NNIP) species. In this study we tested PG treatments using goats for reducing NNIP brush species and...

  16. 36 CFR 251.103 - Mediation of term grazing permit disputes.

    Science.gov (United States)

    2010-07-01

    ... 36 Parks, Forests, and Public Property 2 2010-07-01 2010-07-01 false Mediation of term grazing... Lands § 251.103 Mediation of term grazing permit disputes. (a) Decisions subject to mediation. In those States with Department of Agriculture certified mediation programs, any holder of a term grazing permit...

  17. 36 CFR 222.53 - Grazing fees in the East-noncompetitive procedures.

    Science.gov (United States)

    2010-07-01

    ... lands and the total costs (other than grazing fee costs) of operating on National Forest System lands... the percentage change in the cost of alternative livestock feed. (3) Computation of Annual Grazing Fee... 36 Parks, Forests, and Public Property 2 2010-07-01 2010-07-01 false Grazing fees in the East...

  18. Steers grazing of a rye cover crop influences growth of rye and no-till cotton

    Science.gov (United States)

    Small grain cover crops offer opportunities for grazing but effects on following row crops are not well understood. From 1999 through 2008, stocker steers sequence grazed small grains in a 2-paddock rye-cotton-wheat-fallow- rye rotation. Treatments imposed on rye included 1) zero-grazing from 1999; ...

  19. Nitrogen partitioning and milk production of dairy cows grazing simple and diverse pastures.

    Science.gov (United States)

    Totty, V K; Greenwood, S L; Bryant, R H; Edwards, G R

    2013-01-01

    Research was conducted to examine the effects of a diverse pasture mix on dry matter intake, milk yield, and N partitioning of lactating dairy cows. A pasture containing only ryegrass and white clover (RG), or high-sugar ryegrass and white clover (HS), was compared with a diverse pasture mix (HSD) including chicory, plantain, lotus, high-sugar ryegrass, and white clover. The experiment was conducted over a 10-d period using 3 groups of 12 cows in late lactation. No difference was observed in dry matter (14.3 kg of dry matter/cow per day) or N (583 g of N/cow per day) intake between treatments. The cows grazing the HSD pasture had an increased milk yield (16.9 kg/d) compared with those grazing the simple RG and HS pastures (15.2 and 14.7 kg/d, respectively). However, no differences were observed in milk solids yield for the 3 treatments. A tendency toward greater milk protein yields in the HSD group resulted in improved N use efficiency for milk of 20.4% from the cows fed HSD, compared with 17.8 and 16.7% from cows in the RG and HS treatments, respectively. Urinary N excretion was lower from the cows fed HSD, at 353.8 g/d, compared with 438.3 and 426.6 g/d for cows fed RG and HS, respectively. These results suggest that the use of pastures containing chicory, lotus, and plantain can contribute to the goal of reducing N losses from cows in late lactation. Copyright © 2013 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  20. Biomass requirements from natural pastures for livestock grazing ...

    African Journals Online (AJOL)

    The problem of seasonal shortages of herbage production from natural pastures in the Ethiopian highlands was investigated. This was done by comparing the available biomass amounts on the pastures with biomass amounts required for livestock grazing and for protecting land slope from soil erosion within a given slope ...

  1. Livestock grazing has minimal effect on the species richness and ...

    African Journals Online (AJOL)

    The Succulent Karoo, one of two arid biodiversity hotspots in the world, is known for its high plant species richness, but little is known about the influence of topography and how it mediates the potentially deleterious effects of grazing. Changes in vegetation species composition, cover and species diversity were examined ...

  2. Ingestive Behaviour of Grazing Ewes Given Two Levels of Concentrate

    African Journals Online (AJOL)

    It was expected that concentrate supplementation would reflect directly on forage intake owing to the substitution effect, which causes sheep where the supplement supplied a small proportion of net energy requirement, to have a greater grazing intensity. The two breeds differed in the time spent ruminating or lying, with the ...

  3. Radiobiological problems concerning grazing animals following the Chernobyl accident

    International Nuclear Information System (INIS)

    Prister, B.S.; Lazarev, N.M.; Romanov, L.M.

    1997-01-01

    Chernobyl accident took place on April 26 1986, which was the beginning of the grazing season, when there was not enough fodder on the farms and the cattle was grazed on the open territory. Therefore grazing animal-breeding was the most radioactively affected branch. The consumption of contaminated fodder and surface contamination with radioactive precipitation caused the accumulation of considerable ingested doses in the organisms of animals (up to 1 GY). Radioactive damage caused to the thyroid by the selective accumulation of radioiodine (mainly 131 I) is of particular attention. Cumulative doses of thyroid irradiation in mammals were much higher than for the other organs. Thus, in cows during their grazing on the contaminated pastures outside 30-km zone the ratio of ingested doses of the thyroid and whole body was 130:1 and more, therefore, radiation effects could have a certain negative effect, concerning the agricultural animals in the zone of accidental release influence. Accumulated ingested doses in the thyroid of cows on the contaminated territory in a number of cases caused the complete destruction of the thyroid (doses above 600 Gy), which provided the loss of milk productivity and reproductive qualities of the animals. Lower doses caused the functional disturbances, which in most cases have been levelled during the years after the accident

  4. The evolution of institutions and rules governing communal grazing ...

    African Journals Online (AJOL)

    This paper traces the tradition and evolution of the institutions and rules governing communal grazing lands in Botswana. It shows how the problem of resource overuse arose partly from the dismantling and delegitimization of traditional resource management institutions that occurred during the colonial period, and was ...

  5. Bacterial production, protozoan grazing, and mineralization in stratified Lake Vechten

    NARCIS (Netherlands)

    Bloem, J.

    1989-01-01

    The role of heterotrophic nanoflagellates (HNAN, size 2-20 μm) in grazing on bacteria and mineralization of organic matter in stratified Lake Vechten was studied.

    Quantitative effects of manipulation and fixation on HNAN were checked. Considerable losses were caused by

  6. Assessment of the Effects of Emerging Grazing Policies on Land ...

    African Journals Online (AJOL)

    Journal of Applied Sciences and Environmental Management ... policies on land degradation in Nigeria using soil, vegetation and sustainability as variables for the assessment. ... animals per kilometer square of land and 15,000 persons and 12,500 grazing animals per kilometer square of water. ... OTHER RESOURCES.

  7. Stability, resilience and animal production in continuously grazed ...

    African Journals Online (AJOL)

    The Jones-Sandland model, popularly used in southern Africa, may be criticised because it ignores firstly the long-term effects of grazing intensity on the acceptability and productivity of pasture or veld, and secondly possible discontinuities in the animal performance - stocking rate relationship. A mathematical model is ...

  8. Influence of sward characteristics on grazing behaviour and short ...

    African Journals Online (AJOL)

    Relative to temperate systems, there has been few reported detailed assessments of sward characteristics and associated grazing behavior from natural and ... in highly heterogeneous pastures has the potential to provide integrated (sward, animal, management) strategies for sustainable livestock production in Nigeria.

  9. Phytoplankton growth and microzooplankton grazing in the subtropical Northeast Atlantic.

    Directory of Open Access Journals (Sweden)

    Carlos Cáceres

    Full Text Available Dilution experiments were performed to estimate phytoplankton growth and microzooplankton grazing rates during two Lagrangian surveys in inner and eastern locations of the Eastern North Atlantic Subtropical Gyre province (NAST-E. Our design included two phytoplankton size fractions (0.2-5 µm and >5 µm and five depths, allowing us to characterize differences in growth and grazing rates between size fractions and depths, as well as to estimate vertically integrated measurements. Phytoplankton growth rates were high (0.11-1.60 d(-1, especially in the case of the large fraction. Grazing rates were also high (0.15-1.29 d(-1, suggesting high turnover rates within the phytoplankton community. The integrated balances between phytoplankton growth and grazing losses were close to zero, although deviations were detected at several depths. Also, O2 supersaturation was observed up to 110 m depth during both Lagrangian surveys. These results add up to increased evidence indicating an autotrophic metabolic balance in oceanic subtropical gyres.

  10. The national grazing strategy of the Republic of South Africa ...

    African Journals Online (AJOL)

    The White Paper on Agricultural Policy, tabled in May 1984, made reference to the alarming deterioration of natural rangelands and led to the drawing up of the National Grazing Strategy (NGS), released to parliament in May 1985, which was endorsed by the Department of Agriculture and accepted in its entirety by the ...

  11. The impact of grazing on forage quality of the herbaceous ...

    African Journals Online (AJOL)

    Reports on research conducted in the Mamoro cork oak forest of Morocco to describe the impacts of sheep grazing in March, April, May and June of 1987 and 1988 on seasonal changes in forage quality of the herbaceous vegetation. The study showed that trends in herbage quality were related mainly to plant maturity.

  12. Grazing on Regeneration Sites Encourages Pine Seedling Growth

    Science.gov (United States)

    Raymond D. Ratliff; Renee G. Denton

    1995-01-01

    Effects of season-long, deferred-rotation, and rest-rotation grazing, on ponderosa pine (Pinus ponderosa Dougl. ex Laws.) seedling growth and herbaceous vegetation control were studied in regeneration sites at Boyd Hill, Modoc National Forest, California. Seedlings were planted in 1989. Pine seedling survival and damage did not differ, but the...

  13. The Occurrence and Toxicity of Indospicine to Grazing Animals

    Directory of Open Access Journals (Sweden)

    Mary T. Fletcher

    2015-07-01

    Full Text Available Indospicine is a non-proteinogenic amino acid which occurs in Indigofera species with widespread prevalence in grazing pastures across tropical Africa, Asia, Australia, and the Americas. It accumulates in the tissues of grazing livestock after ingestion of Indigofera. It is a competitive inhibitor of arginase and causes both liver degeneration and abortion. Indospicine hepatoxicity occurs universally across animal species but the degree varies considerably between species, with dogs being particularly sensitive. The magnitude of canine sensitivity is such that ingestion of naturally indospicine-contaminated horse and camel meat has caused secondary poisoning of dogs, raising significant industry concern. Indospicine impacts on the health and production of grazing animals per se has been less widely documented. Livestock grazing Indigofera have a chronic and cumulative exposure to this toxin, with such exposure experimentally shown to induce both hepatotoxicity and embryo-lethal effects in cattle and sheep. In extensive pasture systems, where animals are not closely monitored, the resultant toxicosis may well occur after prolonged exposure but either be undetected, or even if detected not be attributable to a particular cause. Indospicine should be considered as a possible cause of animal poor performance, particularly reduced weight gain or reproductive losses, in pastures where Indigofera are prevalent.

  14. Carcass mass gains of steers grazing star grass, with different ...

    African Journals Online (AJOL)

    Carcass mass gains of steers grazing dryland Cynodon aethiopicus cv. No. 2 Star grass pastures during the growing season were determined for each of 16 treatments comprising four levels of nitrogen fertilisation in combination with four overlapping sets of stocking rates. The treatments were repeated over four growing ...

  15. Holistic Management: Misinformation on the Science of Grazed Ecosystems

    Directory of Open Access Journals (Sweden)

    John Carter

    2014-01-01

    Full Text Available Over 3 billion hectares of lands worldwide are grazed by livestock, with a majority suffering degradation in ecological condition. Losses in plant productivity, biodiversity of plant and animal communities, and carbon storage are occurring as a result of livestock grazing. Holistic management (HM has been proposed as a means of restoring degraded deserts and grasslands and reversing climate change. The fundamental approach of this system is based on frequently rotating livestock herds to mimic native ungulates reacting to predators in order to break up biological soil crusts and trample plants and soils to promote restoration. This review could find no peer-reviewed studies that show that this management approach is superior to conventional grazing systems in outcomes. Any claims of success due to HM are likely due to the management aspects of goal setting, monitoring, and adapting to meet goals, not the ecological principles embodied in HM. Ecologically, the application of HM principles of trampling and intensive foraging are as detrimental to plants, soils, water storage, and plant productivity as are conventional grazing systems. Contrary to claims made that HM will reverse climate change, the scientific evidence is that global greenhouse gas emissions are vastly larger than the capacity of worldwide grasslands and deserts to store the carbon emitted each year.

  16. Research note: Grazing-index method procedures of vegetation ...

    African Journals Online (AJOL)

    In the past, veld condition in the Karoo was assessed using the ecological index methods. This recently changed to the graxing-index method on account of the of the differently estimated grazing-index values being used. The principles governing the method of survey remain the same. The method employs ...

  17. Phosphorus and the grazing ruminant. 1. The effect of ...

    African Journals Online (AJOL)

    M.Sc.-tesis,. Universiteit Stellenbosch. DUDZINSKI, M.L. & ARNOLD, G.W., 1973. Comparison of diets of sheep and cattle grazing together on sown pastures on the southern tablelands of New South Wales by principal components analysis. Aust. J. Agric. Res. 24, 899. DU TOlT, P.J., MALAN, AI. & ROSSOUW, S.D., 1930.

  18. Effects of UV-B irradiated algae on zooplankton grazing

    NARCIS (Netherlands)

    Lange, de H.J.; Lürling, M.F.L.L.W.

    2003-01-01

    We tested the effects of UV-B stressed algae on grazing rates of zooplankton. Four algal species ( Chlamydomonas reinhardtii, Cryptomonas sp., Scenedesmus obliquus and Microcystis aeruginosa) were used as food and fed to three zooplankton species ( Daphnia galeata, Bosmina longirostris and

  19. Research Note Identifying key grazing indicators to monitor trends in ...

    African Journals Online (AJOL)

    Research Note Identifying key grazing indicators to monitor trends in the veld condition of Lambert's Bay Strandveld, South Africa. ... from which a minimum number of species necessary to monitor trends in the condition of the veld were determined, making it user-friendly for land-users, extension officers and others. The key ...

  20. Grazing animal husbandry based on sustainable nutrient management

    NARCIS (Netherlands)

    Hermans, C.; Vereijken, P.H.

    1995-01-01

    Sustainable husbandry systems for grazing animals (cattle and sheep) can be achieved by sustainable nutrient management (SNM). This implies the tuning of inputs to outputs of nutrients, to achieve and maintain optimum ranges of agronomically wanted and ecologically acceptable reserves of single

  1. Improved grazing activity of dairy heifers in shaded tropical grasslands

    Directory of Open Access Journals (Sweden)

    Andréia Cristina Tavares de Mello

    Full Text Available ABSTRACT: Trees in the production systems can effectively reduce hot weather-induced stress in the Brazilian Midwest. High temperatures cause changes in animals daily routine, and trees into pastures can promote benefits. The aim of this research was to evaluate the behavior of dairy heifers in silvopastoral systems in the state of Mato Grosso, Brazil. A herd of 24 crossbreed heifers (3/4 and 7/8 Holstein/Zebu, 350kg average weight, was evaluated over three seasons. Piatã grass was managed under three shade levels: full-sun, moderate-shade, and intensive-shade provided by 10 to 12m high Eucalyptus trees. Behavior data were collected every 15 minutes from 8:30h to 16h. Shade availability significantly impacted heifer behavior, mainly affecting grazing frequency and time during the hottest hours. Grazing behavior was affected by shade levels during the different seasons. Heifers showed preferred grazing times. Heifers in the intensive-shade system visited shady areas during the hottest hours throughout the seasons. Heifers in the full sun-system avoided grazing during the warmer times, ceasing feeding activities. Our results from the Brazilian Midwest showed that shade availability causes breed heifers to change their daily routine.

  2. Phytoplankton Growth and Microzooplankton Grazing in the Subtropical Northeast Atlantic

    Science.gov (United States)

    Cáceres, Carlos; Taboada, Fernando González; Höfer, Juan; Anadón, Ricardo

    2013-01-01

    Dilution experiments were performed to estimate phytoplankton growth and microzooplankton grazing rates during two Lagrangian surveys in inner and eastern locations of the Eastern North Atlantic Subtropical Gyre province (NAST-E). Our design included two phytoplankton size fractions (0.2–5 µm and >5 µm) and five depths, allowing us to characterize differences in growth and grazing rates between size fractions and depths, as well as to estimate vertically integrated measurements. Phytoplankton growth rates were high (0.11–1.60 d−1), especially in the case of the large fraction. Grazing rates were also high (0.15–1.29 d−1), suggesting high turnover rates within the phytoplankton community. The integrated balances between phytoplankton growth and grazing losses were close to zero, although deviations were detected at several depths. Also, O2 supersaturation was observed up to 110 m depth during both Lagrangian surveys. These results add up to increased evidence indicating an autotrophic metabolic balance in oceanic subtropical gyres. PMID:23935946

  3. Surface - atmosphere exchange of ammonia over grazed pasture

    NARCIS (Netherlands)

    Plantaz, M.A.H.G.

    1998-01-01

    This thesis deals with the exchange of ammonia between the atmosphere and grazed pasture in an area of intensive livestock breeding. The term exchange is used because gaseous ammonia can be taken up (dry deposition) as well as released (emission) by this type of surface.
    Ammonia exchange

  4. Assessment of the Effects of Emerging Grazing Policies on Land ...

    African Journals Online (AJOL)

    ADOWIE PERE

    carbon sequestration and water filtration. ... temperature of 13oc in the north during the harmattan in ... vegetation cover is removed with the view to obtain ... data concerning environmental degradation mitigation ... in terrestrial ecosystems and driving processes that .... Grazing systems, ecosystem response, and global.

  5. Effects of rainfall, competition and grazing on flowering of ...

    African Journals Online (AJOL)

    Birds, hares and small antelope consumed 10-50% of the flowers. Size-class distributions indicated that little recent recruitment had taken place on a ranch where palatable plants were scarce and where O. sinuatum flower production was severely depressed by grazing sheep.Language: English. Keywords: Asteraceae ...

  6. Response of mountain meadows to grazing by recreational pack stock

    Science.gov (United States)

    David N. Cole; Jan W. van Wagtendonk; Mitchel P. McClaran; Peggy E. Moore; Neil K. McDougald

    2004-01-01

    Effects of recreational pack stock grazing on mountain meadows in Yosemite National Park were assessed in a 5-year study. Yosemite is a designated wilderness, to be managed such that its natural conditions are preserved. Studies were conducted in 3 characteristic meadow types: shorthair sedge (Carex filifolia Nutt.), Brewer’s reed grass (...

  7. Preliminary survey on tsetse flies and trypanosomosis at grazing ...

    African Journals Online (AJOL)

    Preliminary survey on tsetse flies and trypanosomosis were conducted between. July and August 2007 at grazing fields and villages in and around the Nech Sar national park, with the ultimate intention of forwarding baseline information on the extent of the problem and possible control strategies. . Entomological (Tsetse.

  8. Determining grazing capacity in Namibia with the aid of remote ...

    African Journals Online (AJOL)

    The Namibian rangelands consist of a mixture of herbaceous and woody components. The main source of income is from farming systems with grass production the predominant source of forage. For rangeland managers to utilise this source sustainably, the accurate determination of grazing capacity is vital since it allows ...

  9. Magnetic alignment in grazing and resting cattle and deer

    Czech Academy of Sciences Publication Activity Database

    Begall, S.; Červený, Jaroslav; Neef, J.; Burda, H.; Vojtěch, O.

    2008-01-01

    Roč. 105, č. 36 (2008), s. 13451-13455 ISSN 0027-8424 Institutional research plan: CEZ:AV0Z60930519 Keywords : grazing behavior * magnetic alignment * magnetoreception * resting behavior * spatial orientation Subject RIV: EH - Ecology, Behaviour Impact factor: 9.380, year: 2008

  10. Production response of lambs receiving creep feed while grazing ...

    African Journals Online (AJOL)

    The aim of the study was to determine the production responses of lambs receiving either creep feed or not while grazing two different pastures. The production of ewes within each treatment was also recorded. The study was conducted at both the Kromme Rhee and Langgewens Research Farms. At Kromme Rhee, sheep ...

  11. Effects of Grazing Abandoned Grassland on Herbage Production and Utilization, and Sheep Preference and Performance

    Directory of Open Access Journals (Sweden)

    Håvard Steinshamn

    2018-05-01

    Full Text Available Large areas of farmland are abandoned in Norway, which for various reasons are regarded as undesirable. Loss of farmland may have negative implications for biodiversity and ecosystem function and food production potential. The objectives of this study were to assess forage mass production and utilization, botanical composition, lamb performance, and grazing distribution pattern when reintroducing livestock grazing to an abandoned grassland. The study area was located in Central Norway, unmanaged for 12 years. Sheep grazed the area for 10 weeks in 2013 and 4 weeks in spring and autumn, respectively, in 2014 and 2015. During the summer of 2014 and 2015, the area was subjected to the following replicated treatments: (1 No grazing, (2 grazing with heifers, and (3 grazing with ewes and their offspring. The stocking rate was similar in the grazed treatments. Forage biomass production and animal intake were estimated using grazing exclosure cages and botanical composition by visual assessment. Effect on lamb performance was evaluated by live weight gain and slaughter traits in sheep subjected to three treatments: (1 Common farm procedure with summer range pasturing, (2 spring grazing period extended by 1 month on the abandoned grassland before summer range pasturing, and (3 spring and summer grazing on the abandoned grassland. Grazing distribution patterns were studied using GPS position collars on ewes. Total annual biomass production was on average 72% higher with summer grazing than without. Annual consumption and utilization was on average 218 g DM/m2 and 70% when summer grazed, and 25 g DM/m2 and 18% without grazing, respectively. Botanical composition did not differ between treatments. Live weight gain was higher in lambs subjected to an extended spring grazing period (255 g/d compared to common farm practice (228 g/d and spring and summer grazing on the abandoned grassland (203 g/d, and carcass value was 14% higher in lambs on extended spring

  12. Midcontinent Prairie-Pothole wetlands and climate change: An Introduction to the Supplemental Issue

    Science.gov (United States)

    Mushet, David M.

    2016-01-01

    The multitude of wetlands in the Prairie Pothole Region of North America forms one of Earth’s largest wetland complexes. The midcontinent location exposes this ecologically and economically important wetland system to a highly variable climate, markedly influencing ponded-water levels, hydroperiods, chemical characteristics, and biota of individual basins. Given their dominance on the landscape and recognized value, great interest in how projected future changes in climate will affect prairie-pothole wetlands has developed and spawned much scientific research. On June 2, 2015, a special symposium, “Midcontinent Prairie-Pothole Wetlands: Influence of a Changed Climate,” was held at the annual meeting of the Society of Wetland Scientists in Providence, Rhode Island, USA. The symposium’s twelve presenters covered a wide range of relevant topics delivered to a standing-room-only audience. Following the symposium, the presenters recognized the need to publish their presented papers as a combined product to facilitate widespread distribution. The need for additional papers to more fully cover the topic of prairie-pothole wetlands and climate change was also identified. This supplemental issue of Wetlands is the realization of that vision.

  13. Status of black-tailed prairie dog (Cynomys ludovicianus) in Sonora, Mexico

    Science.gov (United States)

    Reyna A. Castillo-Gamez; Rafael Arenas-Wong; Luis Castillo-Quijada; Verónica Coronado-Peraza; Abigail Enríquez-Munguia; Mirna Federico-Ortega; Alejandra García-Urrutia; Alba Lozano-Gámez; Romeo Méndez-Estrella; Laura Ochoa-Figueroa; J. R. Romo-León; Guy Kruse-Llergo; Iván Parra-Salazar

    2005-01-01

    Prairie dog is a keystone species throughout the habitat where it occurs, but its populations have declined about 98% in the last century. This species has been considered of international importance for the United States of America, Canada, and Mexico. Only two populations are recorded for Mexico, and the westernmost (isolated by Sierra Madre...

  14. Testing for thresholds in a semiarid grassland: The influence of prairie dogs and plague

    Science.gov (United States)

    State and transition models for semiarid grasslands in the Great Plains of North America suggest that the presence of herbivorous black-tailed prairie dogs (Cynomys ludovicianus) on a site (1) creates a vegetation state characterized by increased dominance of annual forbs and unpalatable bunchgrasse...

  15. Rainwater deficit and irrigation demand for row crops in Mississippi Blackland Prairie

    Science.gov (United States)

    Gary Feng; Ying Ouyang; Ardeshir Adeli; John Read; Johnie Jenkins

    2018-01-01

    Irrigation research in the mid-south United States has not kept pace with a steady increase in irrigated area in recent years. This study used rainfall records from 1895 to 2016 to determine rainwater deficit and irrigation demand for soybean [Glycine max (L.) Merr.], corn (Zea mays L.), and cotton (Gossypium hirsutum L.) in the Blackland Prairie region of Mississippi...

  16. Spread of plague among black-tailed prairie dogs is associated with colony spatial characteristics

    Science.gov (United States)

    Johnson, T.L.; Cully, J.F.; Collinge, S.K.; Ray, C.; Frey, C.M.; Sandercock, B.K.

    2011-01-01

    Sylvatic plague (Yersinia pestis) is an exotic pathogen that is highly virulent in black-tailed prairie dogs (Cynomys ludovicianus) and causes widespread colony losses and individual mortality rates >95%. We investigated colony spatial characteristics that may influence inter-colony transmission of plague at 3 prairie dog colony complexes in the Great Plains. The 4 spatial characteristics we considered include: colony size, Euclidean distance to nearest neighboring colony, colony proximity index, and distance to nearest drainage (dispersal) corridor. We used multi-state mark-recapture models to determine the relationship between these colony characteristics and probability of plague transmission among prairie dog colonies. Annual mapping of colonies and mark-recapture analyses of disease dynamics in natural colonies led to 4 main results: 1) plague outbreaks exhibited high spatial and temporal variation, 2) the site of initiation of epizootic plague may have substantially influenced the subsequent inter-colony spread of plague, 3) the long-term effect of plague on individual colonies differed among sites because of how individuals and colonies were distributed, and 4) colony spatial characteristics were related to the probability of infection at all sites although the relative importance and direction of relationships varied among sites. Our findings suggest that conventional prairie dog conservation management strategies, including promoting large, highly connected colonies, may need to be altered in the presence of plague. ?? 2011 The Wildlife Society.

  17. Vegetation dynamics of restored and remnant Willamette Valley, OR wet prairie wetlands

    Science.gov (United States)

    Wet prairie wetlands are now one of the rarest habitat types in the Willamette Valley of Oregon, USA. Less than two percent of their historic extent remains, with most having been converted into agricultural fields (Christy and Alverson 2011, ONHP 1983). This habitat is the obl...

  18. Sediment removal by prairie filter strips in row-cropped ephemeral watersheds

    Science.gov (United States)

    Matthew J. Helmers; Xiaobo Zhou; Heidi Asbjornsen; Randy Kolka; Mark D. Tomer; Richard M. Cruse

    2012-01-01

    Twelve small watersheds in central Iowa were used to evaluate the eff ectiveness of prairie filter strips (PFS) in trapping sediment from agricultural runoff. Four treatments with PFS of different size and location (100% rowcrop, 10% PFS of total watershed area at footslope, 10% PFS at footslope and in contour strips, 20% PFS at footslope and in contour strips)...

  19. Effects of wind energy development on nesting ecology of greater prairie-chickens in fragmented grasslands.

    Science.gov (United States)

    McNew, Lance B; Hunt, Lyla M; Gregory, Andrew J; Wisely, Samantha M; Sandercock, Brett K

    2014-08-01

    Wind energy is targeted to meet 20% of U.S. energy needs by 2030, but new sites for development of renewable energy may overlap with important habitats of declining populations of grassland birds. Greater Prairie-Chickens (Tympanuchus cupido) are an obligate grassland bird species predicted to respond negatively to energy development. We used a modified before-after control-impact design to test for impacts of a wind energy development on the reproductive ecology of prairie-chickens in a 5-year study. We located 59 and 185 nests before and after development, respectively, of a 201 MW wind energy facility in Greater Prairie-Chicken nesting habitat and assessed nest site selection and nest survival relative to proximity to wind energy infrastructure and habitat conditions. Proximity to turbines did not negatively affect nest site selection (β = 0.03, 95% CI = -1.2-1.3) or nest survival (β = -0.3, 95% CI = -0.6-0.1). Instead, nest site selection and survival were strongly related to vegetative cover and other local conditions determined by management for cattle production. Integration of our project results with previous reports of behavioral avoidance of oil and gas facilities by other species of prairie grouse suggests new avenues for research to mitigate impacts of energy development. © 2014 The Authors. Conservation Biology published by Wiley Periodicals, Inc. on behalf of Society for Conservation Biology.

  20. Raptor community composition in the Texas Southern High Plains lesser prairie-chicken range

    Science.gov (United States)

    Behney, A.C.; Boal, Clint W.; Whitlaw, Heather A.; Lucia, D.R.

    2012-01-01

    Predation can be a factor in preventing prey population growth and sustainability when prey populations are small and fragmented, and when predator density is unrelated to the density of the single prey species. We conducted monthly raptor surveys from February 2007 to May 2009 in adjacent areas of the Texas Southern High Plains (USA) that do and do not support lesser prairie-chickens (Tympanuchus pallidicinctus), a candidate for protection under the Endangered Species Act. During the summer period corresponding to prairie-chicken nesting and brood-rearing, Swainson's hawks (Buteo swainsoni) were the most abundant raptor. During the lekking and overwintering period, the raptor community was diverse, with northern harriers (Circus cyaneus) being the most abundant species. Raptor abundance peaked during the early autumn and was lowest during the spring. Utility poles were a significant predictor of raptor density at survey points and Swainson's hawks and all raptors, pooled, were found in greater densities in non-prairie-chicken habitat dominated by mesquite (Prosopis glandulosa). Avian predation risk on prairie-chickens, based on presence and abundance of raptors, appears to be greatest during winter when there is a more abundant and diverse raptor community, and in areas with utility poles.

  1. Preliminary study of prairies forested with Eucalyptus sp. at the northwestern Uruguayan soils

    International Nuclear Information System (INIS)

    Carrasco-Letelier, L.; Eguren, G.; Castineira, C.; Parra, O.; Panario, D.

    2004-01-01

    The forestation of Uruguayan natural prairie soil does not always ensure an increase of soil carbon sink. - The land cover change of Uruguayan Forestal Plan provoked biogeochemical changes on horizon Au 1 of Argiudols; in native prairies which were replaced by monoculture Eucalyptus sp. plantation with 20 year rotations as trees. Five fields forested and six natural prairies were compared. The results not only show a statistical significant soil acidification, diminution of soil organic carbon, increase of aliphaticity degree of humic substances, and increase of affinity and capacity of hydrolytic activity from soil microbial communities for forested sites with Eucalyptus sp. but also, a tendency of podzolization and/or mineralization by this kind of land cover changes, with a net soil organic lost of 16.6 tons ha -1 in the horizon Au 1 of soil under Eucalyptus sp. plantation compared with prairie. Besides, these results point out the necessity of correction of the methodology used by assigned Uruguayan commission to assess the national net emission of greenhouse gases, since the mineralization and/or podzolization process detected in forested soil imply a overestimation of soil organic carbon. The biochemical parameters show a statistical significant correlation between the soil organic carbon status and these parameters which were presented as essential for the correct evaluation of Uruguayan soil carbon sink

  2. Phenotypic and genetic characterization of western prairie clover collections from the western USA

    Science.gov (United States)

    Kishor Bhattarai; B. Shaun Bushman; Douglas A. Johnson; John G. Carman

    2010-01-01

    Few North American legumes are available for rangeland revegetation in the semiarid western United States. Western prairie clover (Dalea ornata [Douglas ex Hook.] Eaton & J. Wright) is a perennial legume with desirable forage characteristics and is distributed in the northern Great Basin, Snake River Basin, and southern Columbia Plateau. Understanding the...

  3. Gallbladder contractility and mucus secretion after cholesterol feeding in the prairie dog

    NARCIS (Netherlands)

    Li, Y. F.; Moody, F. G.; Weisbrodt, N. W.; Zalewsky, C. A.; Coelho, J. C.; Senninger, N.; Gouma, D.

    1986-01-01

    The purpose of our study was to evaluate changes in gallbladder contractility and mucus secretion in vitro during the early stages of gallstone formation in prairie dogs. Thirty-two animals were divided into five groups. Control animals were fed a trace cholesterol diet. Experimental animals were

  4. Searls prairie clover (Dalea searlsiae) for rangeland revegetation: Phenotypic and genetic evaluations

    Science.gov (United States)

    Kishor Bhattarai; Shaun Bushman; Douglas A. Johnson; John G. Carman

    2011-01-01

    Few North American legumes are available for use in rangeland revegetation in the western USA, but Searls prairie clover [Dalea searlsiae (A. Gray) Barneby] is one that holds promise. Commercial-scale seed production of this species could address the issues of unreliable seed availability and high seed costs associated with its wildland seed collection. To evaluate its...

  5. Comparison of cellulosic ethanol yields from midwestern maize and reconstructed tallgrass prairie systems managed for bioenergy

    Science.gov (United States)

    Maize- and prairie-based systems were investigated as cellulosic feedstocks by conducting a 9 ha side-by-side comparison on fertile soils in the Midwestern United States. Maize was grown continuously with adequate fertilization over years both with and without a winter rye cover crop, and the 31-spe...

  6. Population status of prairie dogs (Cynomys ludovicianus) in the San Pedro River Basin, Sonora

    Science.gov (United States)

    Efren Moreno-Arzate; Carlos A. Lopez Gonzalez; Gerardo Carreon Arroyo

    2013-01-01

    The black tailed prairie dog (Cynomys ludovicianus) is a species of conservation concern for Mexico, the United States and Canada. Populations in Mexico (including those in Sonora), which are considered endangered by the Mexican authority, require additional conservation efforts to maintain them on the long term. Our objective was to determine population size and...

  7. Interactions of raptors and Lesser Prairie-Chickens at leks in the Texas Southern High Plains

    Science.gov (United States)

    Behney, Adam C.; Boal, Clint W.; Whitlaw, Heather A.; Lucia, Duane R.

    2011-01-01

    We examined behavioral interactions of raptors, Chihuahuan Ravens (Corvus cryptoleucus), and Lesser Prairie-Chickens (Tympanuchus pallidicinctus) at leks in the Texas Southern High Plains. Northern Harriers (Circus cyaneus) and Swainson's Hawks (Buteo swainsoni) were the most common raptors observed at leks. Only 15 of 61 (25%) raptor encounters at leks (0.09/hr) resulted in a capture attempt (0.02/hr). Mean (± SD) time for Lesser Prairie-Chickens to return to lekking behavior following a raptor encounter was 4.2 ± 5.5 min suggesting the disturbance had little influence on lekking behaviors. Lesser Prairie-Chickens engaged in different escape behaviors depending on raptor species and, generally, did not respond to ravens suggesting they are able to assess different predation risks. The raptors in our study area posed little predation risk to lekking prairie-chickens. Behavioral disturbance at leks appears minimal due to the lack of successful predation events, low raptor encounter rates, and short time to return to lekking behavior.

  8. Environmental Impacts of Wind Power Development on the Population Biology of Greater Prairie-Chickens

    Energy Technology Data Exchange (ETDEWEB)

    Sandercock, Brett K. [Kansas State Univ., Manhattan, KS (United States)

    2013-05-22

    This report summarizes the results of a seven-year, DOE-funded research project, conducted by researchers from Kansas State University and the National Wind Coordinating Collaborative, to assess the effects of wind energy development in Kansas on the population and reproduction of greater prairie chickens.

  9. Land use effects on pesticides in sediments of prairie pothole wetlands in North and South Dakota

    Science.gov (United States)

    McMurry, Scott T.; Belden, Jason B.; Smith, Loren M.; Morrison, Shane A.; Daniel, Dale W.; Euliss, Betty R.; Euliss, Ned H. Jr.; Kensinger, Bart J.; Tangen, Brian

    2016-01-01

    Prairie potholes are the dominant wetland type in the intensively cultivated northern Great Plains of North America, and thus have the potential to receive pesticide runoff and drift. We examined the presence of pesticides in sediments of 151 wetlands split among the three dominant land use types, Conservation Reserve Program (CRP), cropland, and native prairie, in North and South Dakota in 2011. Herbicides (glyphosate and atrazine) and fungicides were detected regularly, with no insecticide detections. Glyphosate was the most detected pesticide, occurring in 61% of all wetlands, with atrazine in only 8% of wetlands. Pyraclostrobin was one of five fungicides detected, but the only one of significance, being detected in 31% of wetlands. Glyphosate was the only pesticide that differed by land use, with concentrations in cropland over four-times that in either native prairie or CRP, which were equal in concentration and frequency of detection. Despite examining several landscape variables, such as wetland proximity to specific crop types, watershed size, and others, land use was the best variable explaining pesticide concentrations in potholes. CRP ameliorated glyphosate in wetlands at concentrations comparable to native prairie and thereby provides another ecosystem service from this expansive program.

  10. Intrusion of soil covered uranium mill tailings by whitetail prairie dogs and Richardson's ground squirrels

    International Nuclear Information System (INIS)

    Shuman, R.

    1984-01-01

    The primary objective of the reclamation of uranium mill tailings is the long-term isolation of the matrial from the biosphere. Fossorial and semi-fossorial species represent a potentially disruptive influence as a result of their burrowing habits. The potential for intrusion was investigated with respect to two sciurids, the whitetail prairie dog (Cynomys leucurus) and Richardson's ground squirrel (Spermophilus richardsonii). Populations of prairie dogs were established on a control area, lacking a tailings layer, and two experimental areas, underlain by a waste layer, in southeastern Wyoming. Weekly measurements of prairie dog mound surface activities were conducted to demonstrate penetration, or lack thereof, of the tailings layer. Additionally, the impact of burrowing upon radon flux was determined. Limited penetration of the waste layer was noted after which frequency of inhabitance of the intruding burrow system declined. No significant changes in radon flux were detected. In another experiment, it was found that Richardson's ground squirrels burrowed to less extreme depths when confronted by mill tailings. Additional work at an inactive tailings pile in western Colorado revealed repeated intrusion through a shallow cover, and subsequent transport of radioactive material to the ground surface by prairie dogs. Radon flux from burrow entrances was significantly greater than that from undisturbed ground. Data suggested that textural and pH properties of tailings material may act to discourage repeated intrusion at some sites. 58 references

  11. Interannual variability in the extent of wetland-stream connectivity within the Prairie Pothole Region

    Science.gov (United States)

    Melanie Vanderhoof; Laurie Alexander

    2016-01-01

    The degree of hydrological connectivity between wetland systems and downstream receiving waters can be expected to influence the volume and variability of stream discharge. The Prairie Pothole Region contains a high density of depressional wetland features, a consequence of glacial retreat. Spatial variability in wetland density, drainage evolution, and precipitation...

  12. Neonicotinoid insecticide removal by prairie strips in row-cropped watersheds with historical seed coating use

    Science.gov (United States)

    Hladik, Michelle L.; Bradbury, Steven; Schulte, Lisa A.; Helmers, Matthew; Witte, Christopher; Kolpin, Dana W.; Garrett, Jessica D.; Harris, Mary

    2017-01-01

    Neonicotinoids are a widely used class of insecticides that are commonly applied as seed coatings for agricultural crops. Such neonicotinoid use may pose a risk to non-target insects, including pollinators and natural enemies of crop pests, and ecosystems. This study assessed neonicotinoid residues in groundwater, surface runoff water, soil, and native plants adjacent to corn and soybean crop fields with a history of being planted with neonicotinoid-treated seeds from 2008-2013. Data from six sites with the same crop management history, three with and three without in-field prairie strips, were collected in 2015-2016, 2-3 years after neonicotinoid (clothianidin and imidacloprid) seed treatments were last used. Three of the six neonicotinoids analyzed were detected in at least one environmental matrix: the two applied as seed coatings on the fields (clothianidin and imidacloprid) and another widely used neonicotinoid (thiamethoxam). Sites with prairie strips generally had lower concentrations of neonicotinoids: groundwater and footslope soil neonicotinoid concentrations were significantly lower in the sites with prairie strips than those without; mean concentrations for groundwater were 11 and 20 ng/L (p = 0.048) and <1 and 6 ng/g (p = 0.0004) for soil, respectively. Surface runoff water concentrations were not significantly (p = 0.38) different for control sites (44 ng/L) or sites with prairie strips (140 ng/L). Consistent with the decreased inputs of neonicotinoids, concentrations tended to decrease over the sampling timeframe. Two sites recorded concentration increases, however, potentially due to disturbance of previous applications or influence from nearby fields where use of seed treatments continued. There were no detections (limit of detection: 1 ng/g) of neonicotinoids in the foliage or roots of plants comprising prairie strips, indicating a low likelihood of exposure to pollinators and other insects visiting these plants following the cessation of seed

  13. Simulating grazing practices in a complete livestock system model: estimating soil carbon storage and greenhouse gas emissions in grazed versus un-grazed agroecosystems using the Manure-DNDC model

    Science.gov (United States)

    Campbell, E. E.; Dorich, C.; Contosta, A.; Varner, R. K.

    2017-12-01

    In livestock agroecosystems, the combined contributions of enteric fermentation, manure management, and livestock grazing and/or feed production play an important role in agroecosystem carbon (C) storage and GHG losses, with complete livestock system models acting as important tools to evaluate the full impacts of these complex systems. The Manure-DeNitrification-DeComposition (DNDC) model is one such example, simulating impacts on C and nitrogen cycling, estimating methane, carbon dioxide, nitrous oxide, and ammonium dynamics in fields, manure storage, and enteric emissions. This allows the evaluation of differences in GHG and soil C impacts between conventional and organic dairy production systems, which differ in their use of grazed pasture versus confined feeding operations. However, Manure-DNDC has received limited testing in representing variations in grazed pasture management (i.e. intensive rotational grazing versus standard grazing practices). Using a set of forage biomass, soil C, and GHG emissions data collected at four sites across New England, we parameterized and validated Manure-DNDC estimations of GHG emissions and soil C in grazed versus un-grazed systems. Soil observations from these sites showed little effect from grazing practices, but larger soil carbon differences between farms. This may be due to spatial variation in SOC, making it difficult to measure and model, or due to controls of edaphic properties that make management moot. However, to further address these questions, model development will be needed to improve Manure-DNDC simulation of rotational grazing, as high stocking density grazing over short periods resulted in forage not re-growing sufficiently within the model. Furthermore, model simulations did not account for variation in interactions between livestock and soil given variability in field microclimates, perhaps requiring simulations that divide a single field into multiple paddocks to move towards more accurate evaluation of

  14. Effect of yearling steer sequence grazing of perennial and annual forages in an integrated crop and livestock system on grazing performance, delayed feedlot entry, finishing performance, carcass measurements, and systems economics.

    Science.gov (United States)

    Sentürklü, Songul; Landblom, Douglas G; Maddock, Robert; Petry, Tim; Wachenheim, Cheryl J; Paisley, Steve I

    2018-06-04

    In a 2-yr study, spring-born yearling steers (n = 144), previously grown to gain <0.454 kg·steer-1·d-1, following weaning in the fall, were stratified by BW and randomly assigned to three retained ownership rearing systems (three replications) in early May. Systems were 1) feedlot (FLT), 2) steers that grazed perennial crested wheatgrass (CWG) and native range (NR) before FLT entry (PST), and 3) steers that grazed perennial CWG and NR, and then field pea-barley (PBLY) mix and unharvested corn (UC) before FLT entry (ANN). The PST and ANN steers grazed 181 d before FLT entry. During grazing, ADG of ANN steers (1.01 ± SE kg/d) and PST steers (0.77 ± SE kg/d) did not differ (P = 0.31). But even though grazing cost per steer was greater (P = 0.002) for ANN vs. PST, grazing cost per kg of gain did not differ (P = 0.82). The ANN forage treatment improved LM area (P = 0.03) and percent i.m. fat (P = 0.001). The length of the finishing period was greatest (P < 0.001) for FLT (142 d), intermediate for PST (91 d), and least for ANN (66 d). Steer starting (P = 0.015) and ending finishing BW (P = 0.022) of ANN and PST were greater than FLT steers. Total FLT BW gain was greater for FLT steers (P = 0.017), but there were no treatment differences for ADG, (P = 0.16), DMI (P = 0.21), G: F (P = 0.82), and feed cost per kg of gain (P = 0.61). However, feed cost per steer was greatest for FLT ($578.30), least for ANN ($276.12), and intermediate for PST ($381.18) (P = 0.043). There was a tendency for FLT steer HCW to be less than ANN and PST, which did not differ (P = 0.076). There was no difference between treatments for LM area (P = 0.094), backfat depth (P = 0.28), marbling score (P = 0.18), USDA yield grade (P = 0.44), and quality grade (P = 0.47). Grazing steer net return ranged from an ANN system high of $9.09/steer to a FLT control system net loss of -$298 and a PST system that was slightly less than the ANN system (-$30.10). Ten-year (2003 to 2012) hedging and net return

  15. Predicting Greater Prairie-Chicken Lek Site Suitability to Inform Conservation Actions.

    Directory of Open Access Journals (Sweden)

    Torre J Hovick

    Full Text Available The demands of a growing human population dictates that expansion of energy infrastructure, roads, and other development frequently takes place in native rangelands. Particularly, transmission lines and roads commonly divide rural landscapes and increase fragmentation. This has direct and indirect consequences on native wildlife that can be mitigated through thoughtful planning and proactive approaches to identifying areas of high conservation priority. We used nine years (2003-2011 of Greater Prairie-Chicken (Tympanuchus cupido lek locations totaling 870 unique leks sites in Kansas and seven geographic information system (GIS layers describing land cover, topography, and anthropogenic structures to model habitat suitability across the state. The models obtained had low omission rates (0.81, indicating high model performance and reliability of predicted habitat suitability for Greater Prairie-Chickens. We found that elevation was the most influential in predicting lek locations, contributing three times more predictive power than any other variable. However, models were improved by the addition of land cover and anthropogenic features (transmission lines, roads, and oil and gas structures. Overall, our analysis provides a hierarchal understanding of Greater Prairie-Chicken habitat suitability that is broadly based on geomorphological features followed by land cover suitability. We found that when land features and vegetation cover are suitable for Greater Prairie-Chickens, fragmentation by anthropogenic sources such as roadways and transmission lines are a concern. Therefore, it is our recommendation that future human development in Kansas avoid areas that our models identified as highly suitable for Greater Prairie-Chickens and focus development on land cover types that are of lower conservation concern.

  16. The innate immune response may be important for surviving plague in wild Gunnison's prairie dogs

    Science.gov (United States)

    Busch, Joseph D.; Van Andel, Roger; Stone, Nathan E.; Cobble, Kacy R.; Nottingham, Roxanne; Lee, Judy; VerSteeg, Michael; Corcoran, Jeff; Cordova, Jennifer; Van Pelt, William E.; Shuey, Megan M.; Foster, Jeffrey T.; Schupp, James M.; Beckstrom-Sternberg, Stephen; Beckstrom-Sternberg, James; Keim, Paul; Smith, Susan; Rodriguez-Ramos, Julia; Williamson, Judy L.; Rocke, Tonie E.; Wagner, David M.

    2013-01-01

    Prairie dogs (Cynomys spp.) are highly susceptible to Yersinia pestis, with ≥99% mortality reported from multiple studies of plague epizootics. A colony of Gunnison's prairie dogs (Cynomys gunnisoni) in the Aubrey Valley (AV) of northern Arizona appears to have survived several regional epizootics of plague, whereas nearby colonies have been severely affected by Y. pestis. To examine potential mechanisms accounting for survival in the AV colony, we conducted a laboratory Y. pestis challenge experiment on 60 wild-caught prairie dogs from AV and from a nearby, large colony with frequent past outbreaks of plague, Espee (n = 30 per colony). Test animals were challenged subcutaneously with the fully virulent Y. pestis strain CO92 at three doses: 50, 5,000, and 50,000 colony-forming units (cfu); this range is lethal in black-tailed prairie dogs (Cynomys ludovicianus). Contrary to our expectations, only 40% of the animals died. Although mortality trended higher in the Espee colony (50%) compared with AV (30%), the differences among infectious doses were not statistically significant. Only 39% of the survivors developed moderate to high antibody levels to Y. pestis, indicating that mechanisms other than humoral immunity are important in resistance to plague. The ratio of neutrophils to lymphocytes was not correlated with plague survival in this study. However, several immune proteins with roles in innate immunity (VCAM-1, CXCL-1, and vWF) were upregulated during plague infection and warrant further inquiry into their role for protection against this disease. These results suggest plague resistance exists in wild populations of the Gunnison's prairie dog and provide important directions for future studies.

  17. Sylvatic plague vaccine partially protects prairie dogs (Cynomys spp.) in field trials

    Science.gov (United States)

    Rocke, Tonie E.; Tripp, Daniel W.; Russell, Robin E.; Abbott, Rachel C.; Richgels, Katherine; Matchett, Marc R.; Biggins, Dean E.; Griebel, Randall; Schroeder, Greg; Grassel, Shaun M.; Pipkin, David R.; Cordova, Jennifer; Kavalunas, Adam; Maxfield, Brian; Boulerice, Jesse; Miller, Michael W.

    2017-01-01

    Sylvatic plague, caused by Yersinia pestis, frequently afflicts prairie dogs (Cynomys spp.), causing population declines and local extirpations. We tested the effectiveness of bait-delivered sylvatic plague vaccine (SPV) in prairie dog colonies on 29 paired placebo and treatment plots (1–59 ha in size; average 16.9 ha) in 7 western states from 2013 to 2015. We compared relative abundance (using catch per unit effort (CPUE) as an index) and apparent survival of prairie dogs on 26 of the 29 paired plots, 12 with confirmed or suspected plague (Y. pestis positive carcasses or fleas). Even though plague mortality occurred in prairie dogs on vaccine plots, SPV treatment had an overall positive effect on CPUE in all three years, regardless of plague status. Odds of capturing a unique animal were 1.10 (95% confidence interval [C.I.] 1.02–1.19) times higher per trap day on vaccine-treated plots than placebo plots in 2013, 1.47 (95% C.I. 1.41–1.52) times higher in 2014 and 1.19 (95% C.I. 1.13–1.25) times higher in 2015. On pairs where plague occurred, odds of apparent survival were 1.76 (95% Bayesian credible interval [B.C.I.] 1.28–2.43) times higher on vaccine plots than placebo plots for adults and 2.41 (95% B.C.I. 1.72–3.38) times higher for juveniles. Our results provide evidence that consumption of vaccine-laden baits can protect prairie dogs against plague; however, further evaluation and refinement are needed to optimize SPV use as a management tool.

  18. Specificity in Sociality: Mice and Prairie Voles Exhibit Different Patterns of Peer Affiliation

    Science.gov (United States)

    Beery, Annaliese K.; Christensen, Jennifer D; Lee, Nicole S.; Blandino, Katrina L.

    2018-01-01

    Social behavior is often described as a unified concept, but highly social (group-living) species exhibit distinct social structures and may make different social decisions. Prairie voles (Microtus ochrogaster) are socially monogamous rodents that often reside in extended family groups, and exhibit robust preferences for familiar social partners (same- and opposite-sex) during extended choice tests, although short-term preferences are not known. Mice (Mus musculus) are gregarious and colonial, but in brief laboratory tests of social preference they typically prefer social novelty. This preference for novel vs. familiar peers may represent a species-specific difference in social decision-making between mice and prairie voles. However, the tests used to measure preferences in each species differ markedly in duration and degree of contact, such that the behaviors cannot be directly compared. We assessed whether social preferences for novelty or familiarity differed between mice and prairie voles of both sexes when assessed with matching protocols: the sociability/social preference test (SPT) typically used in mice (short, no direct contact), and the partner preference test (PPT) used in voles (long, direct contact). A subset of voles also underwent a PPT using barriers (long, no direct contact). In the short SPT, behavior did not differ between species. In the longer test, pronounced partner preferences emerged in prairie voles, but mice exhibited no social preferences and rarely huddled. No sex differences were evident in either test. Direct physical contact was required for partner preferences in huddling time in voles, but preference for the partner chamber was evident with or without contact. Both prairie voles and mice are social, but they exhibit important differences in the specificity and extent of their social behavior. While mice are often used to study social approach and other behaviors, voles are a more suitable species for the study of selective social

  19. Specificity in Sociality: Mice and Prairie Voles Exhibit Different Patterns of Peer Affiliation

    Directory of Open Access Journals (Sweden)

    Annaliese K. Beery

    2018-03-01

    Full Text Available Social behavior is often described as a unified concept, but highly social (group-living species exhibit distinct social structures and may make different social decisions. Prairie voles (Microtus ochrogaster are socially monogamous rodents that often reside in extended family groups, and exhibit robust preferences for familiar social partners (same- and opposite-sex during extended choice tests, although short-term preferences are not known. Mice (Mus musculus are gregarious and colonial, but in brief laboratory tests of social preference they typically prefer social novelty. This preference for novel vs. familiar peers may represent a species-specific difference in social decision-making between mice and prairie voles. However, the tests used to measure preferences in each species differ markedly in duration and degree of contact, such that the behaviors cannot be directly compared. We assessed whether social preferences for novelty or familiarity differed between mice and prairie voles of both sexes when assessed with matching protocols: the sociability/social preference test (SPT typically used in mice (short, no direct contact, and the partner preference test (PPT used in voles (long, direct contact. A subset of voles also underwent a PPT using barriers (long, no direct contact. In the short SPT, behavior did not differ between species. In the longer test, pronounced partner preferences emerged in prairie voles, but mice exhibited no social preferences and rarely huddled. No sex differences were evident in either test. Direct physical contact was required for partner preferences in huddling time in voles, but preference for the partner chamber was evident with or without contact. Both prairie voles and mice are social, but they exhibit important differences in the specificity and extent of their social behavior. While mice are often used to study social approach and other behaviors, voles are a more suitable species for the study of

  20. Lesser prairie-chicken fence collision risk across its northern distribution

    Science.gov (United States)

    Robinson, Samantha G.; Haukos, David A.; Plumb, Reid T.; Hagen, Christian A.; Pitman, James C.; Lautenbach, Joseph M.; Sullins, Daniel S.; Kraft, John D.; Lautenbach, Jonathan D.

    2016-01-01

    Livestock fences have been hypothesized to significantly contribute to mortality of lesser prairie-chickens (Tympanuchus pallidicinctus); however, quantification of mortality due to fence collisions is lacking across their current distribution. Variation in fence density, landscape composition and configuration, and land use could influence collision risk of lesser prairie-chickens. We monitored fences within 3 km of known leks during spring and fall and surveyed for signs of collision occurrence within 20 m of fences in 6 study sites in Kansas and Colorado, USA during 2013 and 2014. We assessed mortality locations of radio-tagged birds (n = 286) for evidence of fence collisions and compared distance to fence relative to random points. Additionally, we quantified locations, propensity, and frequency of fences crossed by lesser prairie-chickens. We tested for landscape and vegetative characteristics that influenced fence-cross propensity and frequency of global positioning system (GPS)-marked birds. A minimum of 12,706 fence crossings occurred by GPS-marked lesser prairie-chickens. We found 3 carcasses and 12 additional possible instances of evidence of collision during >2,800 km of surveyed fences. We found evidence for a single suspected collision based on carcass evidence for 148 mortalities of transmittered birds. Mortality locations of transmittered birds were located at distances from fences 15% farther than expected at random. Our data suggested minimal biological significance and indicated that propensity and frequency of fence crossings were random processes. Lesser prairie-chickens do not appear to be experiencing significant mortality risk due to fence collisions in Kansas and Colorado. Focusing resources on other limiting factors (i.e., habitat quality) has greater potential for impact on population demography than fence marking and removal.

  1. The predicted influence of climate change on lesser prairie-chicken reproductive parameters

    Science.gov (United States)

    Grisham, Blake A.; Boal, Clint W.; Haukos, David A.; Davis, D.; Boydston, Kathy K.; Dixon, Charles; Heck, Willard R.

    2013-01-01

    The Southern High Plains is anticipated to experience significant changes in temperature and precipitation due to climate change. These changes may influence the lesser prairie-chicken (Tympanuchus pallidicinctus) in positive or negative ways. We assessed the potential changes in clutch size, incubation start date, and nest survival for lesser prairie-chickens for the years 2050 and 2080 based on modeled predictions of climate change and reproductive data for lesser prairie-chickens from 2001-2011 on the Southern High Plains of Texas and New Mexico. We developed 9 a priori models to assess the relationship between reproductive parameters and biologically relevant weather conditions. We selected weather variable(s) with the most model support and then obtained future predicted values from climatewizard.org. We conducted 1,000 simulations using each reproductive parameter's linear equation obtained from regression calculations, and the future predicted value for each weather variable to predict future reproductive parameter values for lesser prairie-chickens. There was a high degree of model uncertainty for each reproductive value. Winter temperature had the greatest effect size for all three parameters, suggesting a negative relationship between above-average winter temperature and reproductive output. The above-average winter temperatures are correlated to La Nina events, which negatively affect lesser prairie-chickens through resulting drought conditions. By 2050 and 2080, nest survival was predicted to be below levels considered viable for population persistence; however, our assessment did not consider annual survival of adults, chick survival, or the positive benefit of habitat management and conservation, which may ultimately offset the potentially negative effect of drought on nest survival.

  2. Canola Root–Associated Microbiomes in the Canadian Prairies

    Directory of Open Access Journals (Sweden)

    Chih-Ying Lay

    2018-06-01

    Full Text Available Canola is one of the most economically important crops in Canada, and the root and rhizosphere microbiomes of a canola plant likely impact its growth and nutrient uptake. The aim of this study was to determine whether canola has a core root microbiome (i.e., set of microbes that are consistently selected in the root environment, and whether this is distinct from the core microbiomes of other crops that are commonly grown in the Canadian Prairies, pea, and wheat. We also assessed whether selected agronomic treatments can modify the canola microbiome, and whether this was associated to enhanced yield. We used a field experiment with a randomized complete block design, which was repeated at three locations across the canola-growing zone of Canada. Roots and rhizosphere soil were harvested at the flowering stage of canola. We separately isolated total extractable DNA from plant roots and from adjacent rhizosphere soil, and constructed MiSeq amplicon libraries for each of 60 samples, targeting bacterial, and archaeal 16S rRNA genes and the fungal ITS region. We determined that the microbiome of the roots and rhizosphere of canola was consistently different from those of wheat and pea. These microbiomes comprise several putative plant-growth-promoting rhizobacteria, including Amycolatopsis sp., Serratia proteamaculans, Pedobacter sp., Arthrobacter sp., Stenotrophomonas sp., Fusarium merismoides, and Fusicolla sp., which correlated positively with canola yield. Crop species had a significant influence on bacterial and fungal assemblages, especially within the roots, while higher nutrient input or seeding density did not significantly alter the global composition of bacterial, fungal, or archaeal assemblages associated with canola roots. However, the relative abundance of Olpidium brassicae, a known pathogen of members of the Brassicaceae, was significantly reduced in the roots of canola planted at higher seeding density. Our results suggest that

  3. Modeling Prairie Pothole Lakes: Linking Satellite Observation and Calibration (Invited)

    Science.gov (United States)

    Schwartz, F. W.; Liu, G.; Zhang, B.; Yu, Z.

    2009-12-01

    This paper examines the response of a complex lake wetland system to variations in climate. The focus is on the lakes and wetlands of the Missouri Coteau, which is part of the larger Prairie Pothole Region of the Central Plains of North America. Information on lake size was enumerated from satellite images, and yielded power law relationships for different hydrological conditions. More traditional lake-stage data were made available to us from the USGS Cottonwood Lake Study Site in North Dakota. A Probabilistic Hydrologic Model (PHM) was developed to simulate lake complexes comprised of tens-of-thousands or more individual closed-basin lakes and wetlands. What is new about this model is a calibration scheme that utilizes remotely-sensed data on lake area as well as stage data for individual lakes. Some ¼ million individual data points are used within a Genetic Algorithm to calibrate the model by comparing the simulated results with observed lake area-frequency power law relationships derived from Landsat images and water depths from seven individual lakes and wetlands. The simulated lake behaviors show good agreement with the observations under average, dry, and wet climatic conditions. The calibrated model is used to examine the impact of climate variability on a large lake complex in ND, in particular, the “Dust Bowl Drought” 1930s. This most famous drought of the 20th Century devastated the agricultural economy of the Great Plains with health and social impacts lingering for years afterwards. Interestingly, the drought of 1930s is unremarkable in relation to others of greater intensity and frequency before AD 1200 in the Great Plains. Major droughts and deluges have the ability to create marked variability of the power law function (e.g. up to one and a half orders of magnitude variability from the extreme Dust Bowl Drought to the extreme 1993-2001 deluge). This new probabilistic modeling approach provides a novel tool to examine the response of the

  4. Patterns in Greater Sage-grouse population dynamics correspond with public grazing records at broad scales.

    Science.gov (United States)

    Monroe, Adrian P; Aldridge, Cameron L; Assal, Timothy J; Veblen, Kari E; Pyke, David A; Casazza, Michael L

    2017-06-01

    Human land use, such as livestock grazing, can have profound yet varied effects on wildlife interacting within common ecosystems, yet our understanding of land-use effects is often generalized from short-term, local studies that may not correspond with trends at broader scales. Here we used public land records to characterize livestock grazing across Wyoming, USA, and we used Greater Sage-grouse (Centrocercus urophasianus) as a model organism to evaluate responses to livestock management. With annual counts of male Sage-grouse from 743 leks (breeding display sites) during 2004-2014, we modeled population trends in response to grazing level (represented by a relative grazing index) and timing across a gradient in vegetation productivity as measured by the Normalized Vegetation Difference Index (NDVI). We found grazing can have both positive and negative effects on Sage-grouse populations depending on the timing and level of grazing. Sage-grouse populations responded positively to higher grazing levels after peak vegetation productivity, but populations declined when similar grazing levels occurred earlier, likely reflecting the sensitivity of cool-season grasses to grazing during peak growth periods. We also found support for the hypothesis that effects of grazing management vary with local vegetation productivity. These results illustrate the importance of broad-scale analyses by revealing patterns in Sage-grouse population trends that may not be inferred from studies at finer scales, and could inform sustainable grazing management in these ecosystems. © 2017 by the Ecological Society of America.

  5. Livestock grazing intensity affects abundance of Common shrews (Sorex araneus) in two meadows in Denmark

    Science.gov (United States)

    Schmidt, Niels M; Olsen, Henrik; Leirs, Herwig

    2009-01-01

    Background Current nature conservation in semi-natural grasslands often includes grazing and hay cutting, as well as the abandonment of draining. Semi-natural grassland and in particular meadows constitute important habitat type for a large number of animal species in today's fragmented and intensively cultivated landscape of Europe. Here we focus on the population characteristics of Common shrews Sorex araneus in relation to livestock grazing intensity in two wet meadows in western Denmark. Results High grazing intensity had a significant negative effect on Common shrew number compared to low grazing intensity and no grazing. Common shrew abundance was generally, but not significantly, higher on the low grazing intensity plots than on the ungrazed controls. No differences in body mass, sex ratio, or reproductive output between Common shrew individuals from the various grazing treatments were found. Conclusion No negative effects of low intensity grazing on Common shrew abundance were found compared to the ungrazed control. Low intensity grazing thus seems a suitable management regime for Common shrews, when grazing is needed as part of the meadow management scheme. High intensity grazing on the other hand is not a suitable management tool. PMID:19152713

  6. Livestock grazing intensity affects abundance of Common shrews (Sorex araneus in two meadows in Denmark

    Directory of Open Access Journals (Sweden)

    Olsen Henrik

    2009-01-01

    Full Text Available Abstract Background Current nature conservation in semi-natural grasslands often includes grazing and hay cutting, as well as the abandonment of draining. Semi-natural grassland and in particular meadows constitute important habitat type for a large number of animal species in today's fragmented and intensively cultivated landscape of Europe. Here we focus on the population characteristics of Common shrews Sorex araneus in relation to livestock grazing intensity in two wet meadows in western Denmark. Results High grazing intensity had a significant negative effect on Common shrew number compared to low grazing intensity and no grazing. Common shrew abundance was generally, but not significantly, higher on the low grazing intensity plots than on the ungrazed controls. No differences in body mass, sex ratio, or reproductive output between Common shrew individuals from the various grazing treatments were found. Conclusion No negative effects of low intensity grazing on Common shrew abundance were found compared to the ungrazed control. Low intensity grazing thus seems a suitable management regime for Common shrews, when grazing is needed as part of the meadow management scheme. High intensity grazing on the other hand is not a suitable management tool.

  7. Effect of Mixed Systems on Crop Productivity

    Science.gov (United States)

    Senturklu, Songul; Landblom, Douglas; Cihacek, Larry; Brevik, Eric

    2017-04-01

    The goals of this non-irrigated research has been to determine the effect of mixed systems integration on crop, soil, and beef cattle production in the northern Great Plains region of the United States. Over a 5-year period, growing spring wheat (HRSW-C) continuously year after year was compared to a 5-year crop rotation that included spring wheat (HRSW-R), cover crop (dual crop consisting of winter triticale/hairy vetch seeded in the fall and harvested for hay followed by a 7-species cover crop that was seeded in June after hay harvest), forage corn, field pea/barley, and sunflower. Control 5-year HRSW yield was 2690 kg/ha compared to 2757 kg/ha for HRSW grown in rotation. Available soil nitrogen (N) is often the most important limitation for crop production. Expensive fertilizer inputs were reduced in this study due to the mixed system's complementarity in which the rotation system that included beef cattle grazing sustained N availability and increased nutrient cycling, which had a positive effect on all crops grown in the rotation. Growing HRSW continuously requires less intensive management and in this research was 14.5% less profitable. Whereas, when crop management increased and complementing crops were grown in rotation to produce crops and provide feed for grazing livestock, soil nutrient cycling improved. Increased nutrient cycling increased crop rotation yields and yearling beef cattle steers that grazing annual forages in the rotation gain more body weight than similar steers grazing NGP native range. Results of this long-term research will be presented in a PICO format for participant discussion.

  8. Research and Monitoring Special Use Permit [Minnesota Zoo's Prairie Butterfly Conservation Program on Chase Lake National Wildlife Refuge : 2016

    Data.gov (United States)

    Department of the Interior — The Minnesota Zoo’s Prairie Butterfly Conservation Program partners with numerous federal, state, and local agencies to establish the world’s first and only ex situ...

  9. 77 FR 73827 - Endangered and Threatened Wildlife and Plants; Listing the Lesser Prairie-Chicken as a Threatened...

    Science.gov (United States)

    2012-12-11

    ... the lesser prairie-chicken (Tympanuchus pallidicinctus), a grassland bird known from southeastern... plants; wind energy development; petroleum production; and presence of roads and manmade vertical structures including towers, utility lines, fences, turbines, wells, and buildings. We will request peer...

  10. Sneutrino mixing

    International Nuclear Information System (INIS)

    Grossman, Y.

    1997-10-01

    In supersymmetric models with nonvanishing Majorana neutrino masses, the sneutrino and antisneutrino mix. The conditions under which this mixing is experimentally observable are studied, and mass-splitting of the sneutrino mass eigenstates and sneutrino oscillation phenomena are analyzed

  11. Optimising stocking rate and grazing management to enhance environmental and production outcomes for native temperate grasslands

    Science.gov (United States)

    Badgery, Warwick; Zhang, Yingjun; Huang, Ding; Broadfoot, Kim; Kemp, David; Mitchell, David

    2015-04-01

    Stocking rate and grazing management can be altered to enhance the sustainable production of grasslands but the relative influence of each has not often been determined for native temperate grasslands. Grazing management can range from seasonal rests through to intensive rotational grazing involving >30 paddocks. In large scale grazing, it can be difficult to segregate the influence of grazing pressure from the timing of utilisation. Moreover, relative grazing pressure can change between years as seasonal conditions influence grassland production compared to the relative constant requirements of animals. This paper reports on two studies in temperate native grasslands of northern China and south eastern Australia that examined stocking rate and regionally relevant grazing management strategies. In China, the grazing experiment involved combinations of a rest, moderate or heavy grazing pressure of sheep in spring, then moderate or heavy grazing in summer and autumn. Moderate grazing pressure at 50% of the current district average, resulted in the better balance between maintaining productive and diverse grasslands, a profitable livestock system, and mitigation of greenhouse gases through increased soil carbon, methane uptake by the soil, and efficient methane emissions per unit of weight gain. Spring rests best maintained a desirable grassland composition, but had few other benefits and reduced livestock productivity due to lower feed quality from grazing later in the season. In Australia, the grazing experiment compared continuous grazing to flexible 4- and 20-paddock rotational grazing systems with sheep. Stocking rates were adjusted between systems biannually based on the average herbage mass of the grassland. No treatment degraded the perennial pasture composition, but ground cover was maintained at higher levels in the 20-paddock system even though this treatment had a higher stocking rate. Overall there was little difference in livestock production (e.g. kg

  12. Grooming behaviors of black-tailed prairie dogs are influenced by flea parasitism, conspecifics, and proximity to refuge

    Science.gov (United States)

    Eads, David A.; Biggins, Dean E.; Eads, Samantha L.

    2017-01-01

    Grooming is a common animal behavior that aids in ectoparasite defense. Ectoparasites can stimulate grooming, and natural selection can also favor endogenous mechanisms that evoke periodic bouts of “programmed” grooming to dislodge or kill ectoparasites before they bite or feed. Moreover, grooming can function as a displacement or communication behavior. We compared the grooming behaviors of adult female black-tailed prairie dogs (Cynomys ludovicianus) on colonies with or without flea control via pulicide dust. Roughly 91% of the prairie dogs sampled on the non-dusted colony carried at least one flea, whereas we did not find fleas on two dusted colonies. During focal observations, prairie dogs on the non-dusted colony groomed at higher frequencies and for longer durations than prairie dogs on the dusted colonies, lending support to the hypothesis that fleas stimulated grooming. However, the reduced amount of time spent grooming on the dusted colonies suggested that approximately 25% of grooming might be attributed to factors other than direct stimulation from ectoparasites. Non-dusted colony prairie dogs rarely autogroomed when near each other. Dusted colony prairie dogs autogroomed for shorter durations when far from a burrow opening (refuge), suggesting a trade-off between self-grooming and antipredator defense. Allogrooming was detected only on the non-dusted colony and was limited to adult females grooming young pups. Grooming appears to serve an antiparasitic function in C. ludovicianus. Antiparasitic grooming might aid in defense against fleas that transmit the plague bacterium Yersinia pestis. Plague was introduced to North America ca. 1900 and now has a strong influence on most prairie dog populations, suggesting a magnified effect of grooming on prairie dog fitness.

  13. Environmental radioiodine in thyroids of grazing animals

    International Nuclear Information System (INIS)

    Van Middlesworth, L.

    1990-01-01

    Animal thyroids are excellent indicators of environmental contamination from radioiodine, a fact largely unappreciated before 1954. From continuous monitoring of excised thyroids in Nal well-detectors, we know that high-altitude releases of mixed fission products caused increases of 10 3 to 10 5 times the minimal detectable level of 131 I (3.7 mBq/g) in sheep thyroids from the United States, Europe, Asia, Australia, and New Zealand. Within 6 weeks after high-altitude releases, sheep thyroids from different continents of the same hemisphere contained comparable concentrations of 131 I: more than 10 4 times greater concentrations than cow's milk and 5 x 10 3 times greater concentrations than human thyroids from similar areas. In contrast, during the low-altitude Chernobyl release, average 131 I concentrations in animal thyroids, at distances greater than 1,200 km from Chernobyl, were distributed as the inverse square of the distance from the source. 129 I concentrations measured since 1984 with a germanium well-detector in thyroids of sheep slaughtered in Birmingham, England, ranged from 3 to 50 mBq/g organ weight. Similar quantities of 125 I were present intermittently in thyroids of sheep slaughtered in Birmingham since 1986. The source of the 125 I, which is not a fission product, is not clear. For comparison, deer thyroids from the Savannah River Reservation, USA, contained 10 to 7 x 10 5 mBq 129 I/g. Although this isotope is not a biological hazard, it is a long-lived tracer of fission products

  14. An X-ray grazing incidence phase multilayer grating

    CERN Document Server

    Chernov, V A; Mytnichenko, S V

    2001-01-01

    An X-ray grazing incidence phase multilayer grating, representing a thin grating placed on a multilayer mirror, is proposed. A high efficiency of grating diffraction can be obtained by the possibility of changing the phase shift of the wave diffracted from the multilayer under the Bragg and total external reflection conditions. A grazing incidence phase multilayer grating consisting of Pt grating stripes on a Ni/C multilayer and optimized for the hard X-ray range was fabricated. Its diffraction properties were studied at photon energies of 7 and 8 keV. The obtained maximum value of the diffraction efficiency of the +1 grating order was 9% at 7 keV and 6.5% at 8 keV. The data obtained are in a rather good accordance with the theory.

  15. Invariant polygons in systems with grazing-sliding.

    Science.gov (United States)

    Szalai, R; Osinga, H M

    2008-06-01

    The paper investigates generic three-dimensional nonsmooth systems with a periodic orbit near grazing-sliding. We assume that the periodic orbit is unstable with complex multipliers so that two dominant frequencies are present in the system. Because grazing-sliding induces a dimension loss and the instability drives every trajectory into sliding, the system has an attractor that consists of forward sliding orbits. We analyze this attractor in a suitably chosen Poincare section using a three-parameter generalized map that can be viewed as a normal form. We show that in this normal form the attractor must be contained in a finite number of lines that intersect in the vertices of a polygon. However the attractor is typically larger than the associated polygon. We classify the number of lines involved in forming the attractor as a function of the parameters. Furthermore, for fixed values of parameters we investigate the one-dimensional dynamics on the attractor.

  16. Adjustable Grazing-Incidence X-Ray Optics

    Science.gov (United States)

    O'Dell, Stephen L.; Reid, Paul B.

    2015-01-01

    With its unique subarcsecond imaging performance, NASA's Chandra X-ray Observatory illustrates the importance of fine angular resolution for x-ray astronomy. Indeed, the future of x-ray astronomy relies upon x-ray telescopes with comparable angular resolution but larger aperture areas. Combined with the special requirements of nested grazing-incidence optics, mass, and envelope constraints of space-borne telescopes render such advances technologically and programmatically challenging. The goal of this technology research is to enable the cost-effective fabrication of large-area, lightweight grazing-incidence x-ray optics with subarcsecond resolution. Toward this end, the project is developing active x-ray optics using slumped-glass mirrors with thin-film piezoelectric arrays for correction of intrinsic or mount-induced distortions.

  17. Active Full-Shell Grazing-Incidence Optics

    Science.gov (United States)

    Davis, Jacqueline M.; Elsner, Ronald F.; Ramsey, Brian D.; O'Dell, Stephen L.; Kolodziejczak, Jeffery; Weisskopf, Martin C.; Gubarev, Mikhail V.

    2016-01-01

    MSFC has a long history of developing full-shell grazing-incidence x-ray optics for both narrow (pointed) and wide field (surveying) applications. The concept presented in this paper shows the potential to use active optics to switch between narrow and wide-field geometries, while maintaining large effective area and high angular resolution. In addition, active optics has the potential to reduce errors due to mounting and manufacturing lightweight optics. The design presented corrects low spatial frequency error and has significantly fewer actuators than other concepts presented thus far in the field of active x-ray optics. Using a finite element model, influence functions are calculated using active components on a full-shell grazing-incidence optic. Next, the ability of the active optic to effect a change of optical prescription and to correct for errors due to manufacturing and mounting is modeled.

  18. Aerial surveys adjusted by ground surveys to estimate area occupied by black-tailed prairie dog colonies

    Science.gov (United States)

    Sidle, John G.; Augustine, David J.; Johnson, Douglas H.; Miller, Sterling D.; Cully, Jack F.; Reading, Richard P.

    2012-01-01

    Aerial surveys using line-intercept methods are one approach to estimate the extent of prairie dog colonies in a large geographic area. Although black-tailed prairie dogs (Cynomys ludovicianus) construct conspicuous mounds at burrow openings, aerial observers have difficulty discriminating between areas with burrows occupied by prairie dogs (colonies) versus areas of uninhabited burrows (uninhabited colony sites). Consequently, aerial line-intercept surveys may overestimate prairie dog colony extent unless adjusted by an on-the-ground inspection of a sample of intercepts. We compared aerial line-intercept surveys conducted over 2 National Grasslands in Colorado, USA, with independent ground-mapping of known black-tailed prairie dog colonies. Aerial line-intercepts adjusted by ground surveys using a single activity category adjustment overestimated colonies by ≥94% on the Comanche National Grassland and ≥58% on the Pawnee National Grassland. We present a ground-survey technique that involves 1) visiting on the ground a subset of aerial intercepts classified as occupied colonies plus a subset of intercepts classified as uninhabited colony sites, and 2) based on these ground observations, recording the proportion of each aerial intercept that intersects a colony and the proportion that intersects an uninhabited colony site. Where line-intercept techniques are applied to aerial surveys or remotely sensed imagery, this method can provide more accurate estimates of black-tailed prairie dog abundance and trends

  19. Bite frequency measured by head pitch movements in grazing experiment

    DEFF Research Database (Denmark)

    Oudshoorn, Frank W.; S. Nadimi, Esmaeil; Jørgensen, Rasmus Nyholm

    2010-01-01

    . ECPLF      2007 Skiathos, Greece. p 111-116 Pulido, R.G. & Leaver, J.D., 2001. Quantifying the influence of sward height, concentrate level and initial      milk yield on the milk production and grazing behaviour of continuously stocked dairy cows. Grass      and Forage Science 56, 57-67.    ...

  20. Grazing and metabolism of Euphausia pacifica in the Yellow Sea.

    Directory of Open Access Journals (Sweden)

    Zhencheng Tao

    Full Text Available Grazing and metabolism of Euphausia pacifica in the Yellow Sea were studied from September 2006 to August 2007. Euphausia pacifica is a selective-feeding omnivore and grazing rates among different months were monitored using a Coulter Counter and batch culture feeding experiments. Euphausia pacifica mainly grazed microzooplankton in August and September, which resulted in an increase in chlorophyll a concentration. Oxygen consumption rate of E. pacifica was 38.7-42.5 μmol O2 g(-1 DW h(-1 in March, which was four times higher than the oxygen consumption rates in September and December. The vigorous metabolism of E. pacifica in March consumed 3.1% of body carbon daily, which is likely related to its high reproduction and grazing rate. Respiration and metabolism of E. pacifica in September and December were similar and were lower. O:N ratio of E. pacifica was the highest (17.3-23.8 in March when spawning activity occurred and when food was abundant. The energetic source of E. pacifica during September and December was mostly protein from eating a carnivorous diet, including such items as microzooplankton. Euphausia pacifica was found in cold water at the bottom of the Yellow Sea in summer and autumn and maintained a low consumption status. O:N ratios of E. pacifica in March, September, and December were negatively correlated with SSTs and no significant correlation was found between O:N ratios and chlorophyll a concentration. Seawater temperature is clearly the most important parameter influencing the metabolism of E. pacifica.

  1. Longitudinal Trajectories and Inter-parental Dynamics of Prairie Vole Biparental Care

    Directory of Open Access Journals (Sweden)

    Forrest D. Rogers

    2018-06-01

    Full Text Available For altricial mammalian species, early life social bonds are constructed principally between offspring and their mothers, and the mother-offspring relationship sets the trajectory for offspring bio-behavioral development. In the rare subset of monogamous and biparental species, offspring experience an expanded social network which includes a father. Accordingly, in biparental species fathers also have the potential to influence trajectories of offspring development. Previous semi-natural and laboratory study of one monogamous and biparental species, the prairie vole (Microtus ochrogaster, has given insight into the role that mothers and fathers play in shaping behavioral phenotypes of offspring. Of particular interest is the influence of biparental care in the development of monogamous behavior in offspring. Here, we first briefly review that influence. We then present novel research which describes how parental investment in prairie voles changes across sequential litters of pups, and the extent to which it is coordinated between mothers and fathers. We use approximately 6 years of archival data on prairie vole parenting to investigate trajectories and inter-parent dynamics in prairie vole parenting. We use a series of latent growth models to assess the stability of parental investment across the first 4 l. Our findings suggest that prairie voles display sexually dimorphic patterns of change in parental behavior: mothers' investment declines linearly whereas fathers' pattern of change is characterized by initial decline between litters 1 and 2 with subsequent increase from litters 2 to 4. Our findings also support a conclusion that prairie vole paternal care may be better characterized as compensatory—that is, fathers may compensate for decline in maternal investment. Opposing trends in investment between mothers and fathers ultimately imply stability in offspring investment across sequential litters. These findings, combined with previous

  2. Decline of Hesperia ottoe (Lepidoptera: Hesperiidae in Northern Tallgrass Prairie Preserves

    Directory of Open Access Journals (Sweden)

    Ann B. Swengel

    2013-11-01

    Full Text Available We counted butterflies on transect surveys during Hesperia ottoe flight period in 1988–2011 at tallgrass prairie preserves in four states (Illinois, Iowa, Minnesota, Wisconsin, divided into units cross-referenced to vegetation type and management history. H. ottoe occurred only in dry and sand prairie types, and was significantly more abundant in undegraded than semi-degraded prairie, and in discontinuous sod (with numerous unvegetated areas due to bare sand and/or rock outcrops than in continuous sod. This skipper was significantly more abundant in small sites compared to medium and large sites, even when the analysis was limited to undegraded prairie analyzed separately by sod type. H. ottoe was significantly under-represented in year-burn 0 (the first growing season after fire compared to an expected distribution proportional to survey effort. However, H. ottoe was also over-represented in fire-managed units compared to non-fire-managed units. However, by far most units and sites were in fire management and most populations declined to subdetection during this study. Peak abundance post-fire occurred in a later year-burn in discontinuous sod and was much higher than in continuous sod. We also analyze H. ottoe status and trend in midwestern prairie preserves by compiling a dataset of our and others’ butterfly surveys from 1974 to 2011. Only 1/9 sites with continuous sod had detectable H. ottoe in recent year(s. In discontinuous sod, 2/6 did, with two sites lacking data for the last few years. The number of years H. ottoe was still detectable after preservation and the number of years to consistent non-detection were both significantly higher in discontinuous than continuous sod. Both measures of population persistence averaged over twice as long in discontinuous than continuous sod, and correlated negatively with prairie size. The year when consistent non-detection began varied over several decades among sites. Despite the currently urgent

  3. Decline of Hesperia ottoe (Lepidoptera: Hesperiidae) in Northern Tallgrass Prairie Preserves.

    Science.gov (United States)

    Swengel, Ann B; Swengel, Scott R

    2013-11-20

    We counted butterflies on transect surveys during Hesperia ottoe flight period in 1988-2011 at tallgrass prairie preserves in four states (Illinois, Iowa, Minnesota, Wisconsin), divided into units cross-referenced to vegetation type and management history. H. ottoe occurred only in dry and sand prairie types, and was significantly more abundant in undegraded than semi-degraded prairie, and in discontinuous sod (with numerous unvegetated areas due to bare sand and/or rock outcrops) than in continuous sod. This skipper was significantly more abundant in small sites compared to medium and large sites, even when the analysis was limited to undegraded prairie analyzed separately by sod type. H. ottoe was significantly under-represented in year-burn 0 (the first growing season after fire) compared to an expected distribution proportional to survey effort. However, H. ottoe was also over-represented in fire-managed units compared to non-fire-managed units. However, by far most units and sites were in fire management and most populations declined to subdetection during this study. Peak abundance post-fire occurred in a later year-burn in discontinuous sod and was much higher than in continuous sod. We also analyze H. ottoe status and trend in midwestern prairie preserves by compiling a dataset of our and others' butterfly surveys from 1974 to 2011. Only 1/9 sites with continuous sod had detectable H. ottoe in recent year(s). In discontinuous sod, 2/6 did, with two sites lacking data for the last few years. The number of years H. ottoe was still detectable after preservation and the number of years to consistent non-detection were both significantly higher in discontinuous than continuous sod. Both measures of population persistence averaged over twice as long in discontinuous than continuous sod, and correlated negatively with prairie size. The year when consistent non-detection began varied over several decades among sites. Despite the currently urgent need to identify

  4. Partial replacement of corn grain by hydrogenated oil in grazing dairy cows in early lactation.

    Science.gov (United States)

    Salado, E E; Gagliostro, G A; Becu-Villalobos, D; Lacau-Mengido, I

    2004-05-01

    Thirty-six grazing dairy cows were used to determine milk production and composition, and dry matter and energy intake when corn grain was partially replaced by hydrogenated oil in the concentrate. Four additional cows, each fitted with a ruminal cannula, were used in a crossover design to evaluate effects of supplemental fat on rumen environment and pasture digestion. All cows grazed mixed pastures with an herbage allowance of 30 kg dry matter/cow per day. The control group was fed a concentrate containing corn grain (4.49 kg dry matter/cow per day) and fishmeal (0.37 kg dry matter/cow per day), whereas the other group (fat) received a concentrate containing corn grain (2.87 kg dry matter/cow per day), fishmeal (0.37 kg dry matter/cow per day) and fat (0.7 kg dry matter/cow per day). The fat was obtained by hydrogenation of vegetable oils (melting point 58 to 60 degrees C, 30.3% C16:0, 34.9% C18:0, 21.8% C18:1, 3.3% C18:2). Supplemental fat increased milk production (control = 23.7 vs. fat = 25.0 kg/cow per day), fat-corrected milk (control = 22.5 vs. fat = 24.5 kg/cow per day), milk fat content (control = 3.64% vs. fat = 3.86%) and yields of milk fat (control = 0.86 vs. fat = 0.97 kg/cow per day) and protein (control = 0.74 vs. fat = 0.78 kg/cow per day). Milk percentages of protein, lactose, casein, cholesterol, and urea nitrogen were not affected. Pasture DMI and total DMI of pasture and concentrate and estimated energy intake were unchanged. No differences in loss of body weight or body condition score were detected. Plasma concentrations of nonesterified fatty acids, somatotropin, insulin, and insulin-like growth factor were not affected by supplemental fat. Concentrations of plasma triglyceride and total cholesterol were increased by supplemented fat, and no changes in plasma glucose and urea nitrogen were observed. The acetate-to-propionate ratio was higher in rumen fluid of cows that consumed fat (fat = 3.39 vs. control = 3.27). In situ pasture NDF

  5. Spatial Distribution of Nitrogen on Grazed Karst Landscapes

    Directory of Open Access Journals (Sweden)

    Douglas G. Boyer

    2001-01-01

    Full Text Available The impact on water quality by agricultural activity in karst terrain is an important consideration for resource management within the Appalachian region. Karst areas comprise about 18% of the region’s land area. An estimated one-third of the region’s farms, cattle, and agricultural market value are located on karst terrain. Mean nitrate concentrations in several karst springs in southeastern West Virginia exhibit a strong linear relationship with the percentage of agriculture land cover. Development of best management practices for efficient nitrogen (N use and reduction of outflow of N to water from karst areas requires knowledge about N dynamics on those landscapes. Water extractable NO3-N and NH4-N were measured along transects at four soil depths in two grazed sinkholes and one wooded sinkhole. Distribution of soil NO3-N and NH4-N were related to frequency of animal presence and to topographic and hydrologic redistribution of soil and fecal matter in the grazed sinkholes. Karst pastures are characterized by under drainage and funneling of water and contaminants to the shallow aquifer. Control of NO3-N leaching from karst pasture may depend on management strategies that change livestock grazing behavior in sinkholes and reduce the opportunity for water and contaminants to quickly reach sinkhole drains.

  6. The ability of winter grazing to reduce wildfire size, intensity ...

    Science.gov (United States)

    A recent study by Davies et al. sought to test whether winter grazing could reduce wildfire size, fire behavior metrics, and fire-induced plant mortality in shrub-grasslands. The authors concluded that ungrazed rangelands may experience more fire-induced mortality of native perennial bunchgrasses. The authors also presented several statements regarding the benefits of winter grazing on post-fire plant community responses. However, this commentary will show that the study by Davies et al. has underlying methodological flaws, lacks data necessary to support their conclusions, and does not provide an accurate discussion on the effect of grazing on rangeland ecosystems. Importantly, Davies et al. presented no data on the post-fire mortality of the perennial bunchgrasses or on the changes in plant community composition following their experimental fires. Rather, Davies et al. inferred these conclusions based off their observed fire behavior metrics of maximum temperature and a term described as the “heat load”. However, neither metric is appropriate for elucidating the heat flux impacts on plants. This lack of post-fire data, several methodological flaws, and the use of inadequate metrics describing heat cast doubts on the authors’ ability to support their stated conclusions. This article is a commentary highlights the scientific shortcomings in a forthcoming paper by Davies et al. in the International Journal of Wildland Fire. The study has methodological flaw

  7. Grazing Soybean to Increase Voluntary Cow Traffic in a Pasture-based Automatic Milking System

    Directory of Open Access Journals (Sweden)

    C. E. F. Clark

    2014-03-01

    Full Text Available Pasture-based automatic milking systems (AMS require cow traffic to enable cows to be milked. The interval between milkings can be manipulated by strategically allocating pasture. The current experiment investigated the effect of replacing an allocation of grazed pasture with grazed soybean (Glycine max with the hypothesis that incorporating soybean would increase voluntary cow traffic and milk production. One hundred and eighty mixed age, primiparous and multiparous Holstein-Friesian/Illawarra cows were randomly assigned to two treatment groups (n = 90/group with a 2×2 Latin square design. Each group was either offered treatments of kikuyu grass (Pennisetum clandestinum Hoach ex Chiov. pasture (pasture or soybean from 0900 h to 1500 h during the experimental period which consisted of 2 periods of 3 days following 5 days of training and adaptation in each period with groups crossing over treatments after the first period. The number of cows trafficking to each treatment was similar together with milk yield (mean ≈18 L/cow/d in this experiment. For the cows that arrived at soybean or pasture there were significant differences in their behaviour and consequently the number of cows exiting each treatment paddock. There was greater cow traffic (more cows and sooner exiting pasture allocations. Cows that arrived at soybean stayed on the allocation for 25% more time and ate more forage (8.5 kg/cow/d/allocation relative to pasture (4.7 kg/cow/d/allocation. Pasture cows predominantly replaced eating time with rumination. These findings suggest that replacing pasture with alternative grazeable forages provides no additional incentive to increase voluntary cow traffic to an allocation of feed in AMS. This work highlights the opportunity to increase forage intakes in AMS through the incorporation of alternative forages.

  8. Introducing cattle grazing to a noxious weed-dominated rangeland shifts plant communities

    Directory of Open Access Journals (Sweden)

    Josh S. Davy

    2015-10-01

    Full Text Available Invasive weed species in California's rangelands can reduce herbaceous diversity, forage quality and wildlife habitat. Small-scale studies (5 acres or fewer have shown reductions of medusahead and yellow starthistle using prescribed grazing on rangelands, but little is published on the effects of pasture-scale (greater than 80 acres prescribed grazing on weed control and plant community responses. We report the results of a 6-year collaborative study of manager-applied prescribed grazing implemented on rangeland that had not been grazed for 4 years. Grazing reduced medusahead but did not alter yellow starthistle cover. Medusahead reductions were only seen in years that did not have significant late spring rainfall, suggesting that it is able to recover from heavy grazing if soil moisture is present. Later season grazing appears to have the potential to suppress medusahead in all years. In practice, however, such grazing is constrained by livestock drinking water availability and forage quality, which were limited even in years with late spring rainfall. Thus, we expect that grazing treatments under real-world constraints would reduce medusahead only in years with little late spring rainfall. After 10 years of grazing exclusion, the ungrazed plant communities began to shift, replacing medusahead with species that have little value, such as ripgut and red brome.

  9. Dynamics of forage accumulation in Elephant grass subjected to rotational grazing intensities

    Directory of Open Access Journals (Sweden)

    Braulio Maia de Lana Sousa

    2013-09-01

    Full Text Available We assessed the accumulation dynamics of forage and its components in Elephant grass cv. Napier (Pennisetum purpureum Schum. that were subjected to three post-grazing height treatments (30, 50, and 70 cm from February through May 2009 (experiment one and December 2009 through May 2010 (experiment two. In experiment one, the grazing events started when the light interception by the canopy reached 95%. The same was adopted for experiment two, except for the first grazing event, which was based on the height of the apical meristems of basal tillers. The experimental design for both experiments was a randomized complete block with three replications. The pastures that were managed at a post-grazing height of 30 cm exhibited lower rates of leaf and stem growth, total growth and forage accumulation than those that were managed at 50 or 70 cm, indicating that post-grazing height affects Elephant grass. The pastures that were managed at 50 cm exhibited relatively stable accumulation rates and less stem accumulation. Pastures managed at 70 cm of pos-grazing height presented more leaf and stem accumulation. Most apical meristems of Elephant grass should be removed in the first grazing when they reach the post-grazing target height of 50 cm. The elevation in the residual post-grazing height, especially in the summer, raises the regrowth vigor in the Elephant grass cv. Napier pasture. The post-grazing height of 30 cm reduces the growth of the Elephant grass cv. Napier.

  10. Apparent field safety of a raccoon poxvirus-vectored plague vaccine in free-ranging prairie dogs (Cynomys spp.), Colorado, USA.

    Science.gov (United States)

    Tripp, Daniel W; Rocke, Tonie E; Streich, Sean P; Abbott, Rachel C; Osorio, Jorge E; Miller, Michael W

    2015-04-01

    Prairie dogs (Cynomys spp.) suffer high rates of mortality from plague. An oral sylvatic plague vaccine using the raccoon poxvirus vector (designated RCN-F1/V307) has been developed for prairie dogs. This vaccine is incorporated into palatable bait along with rhodamine B as a biomarker. We conducted trials in August and September 2012 to demonstrate uptake and apparent safety of the RCN-F1/V307 vaccine in two prairie dog species under field conditions. Free-ranging prairie dogs and other associated small rodents readily consumed vaccine-laden baits during field trials with no apparent adverse effects; most sampled prairie dogs (90%) and associated small rodents (78%) had consumed baits. Visual counts of prairie dogs and their burrows revealed no evidence of prairie dog decline after vaccine exposure. No vaccine-related morbidity, mortality, or gross or microscopic lesions were observed. Poxviruses were not isolated from any animal sampled prior to bait distribution or on sites that received placebo baits. We isolated RCN-F1/V307 from 17 prairie dogs and two deer mice (Peromyscus maniculatus) captured on sites where vaccine-laden baits were distributed. Based on these findings, studies examining the utility and effectiveness of oral vaccination to prevent plague-induced mortality in prairie dogs and associated species are underway.

  11. Apparent field safety of a raccoon poxvirus-vectored plague vaccine in free-ranging prairie dogs (Cynomys spp.), Colorado, USA

    Science.gov (United States)

    Tripp, Daniel W.; Rocke, Tonie E.; Streich, Sean P.; Abbott, Rachel C.; Osorio, Jorge E.; Miller, Michael W.

    2015-01-01

    Prairie dogs (Cynomys spp.) suffer high rates of mortality from plague. An oral sylvatic plague vaccine using the raccoon poxvirus vector (designated RCN-F1/V307) has been developed for prairie dogs. This vaccine is incorporated into palatable bait along with rhodamine B as a biomarker. We conducted trials in August and September 2012 to demonstrate uptake and apparent safety of the RCN-F1/V307 vaccine in two prairie dog species under field conditions. Free-ranging prairie dogs and other associated small rodents readily consumed vaccine-laden baits during field trials with no apparent adverse effects; most sampled prairie dogs (90%) and associated small rodents (78%) had consumed baits. Visual counts of prairie dogs and their burrows revealed no evidence of prairie dog decline after vaccine exposure. No vaccine-related morbidity, mortality, or gross or microscopic lesions were observed. Poxviruses were not isolated from any animal sampled prior to bait distribution or on sites that received placebo baits. We isolated RCN-F1/V307 from 17 prairie dogs and two deer mice (Peromyscus maniculatus) captured on sites where vaccine-laden baits were distributed. Based on these findings, studies examining the utility and effectiveness of oral vaccination to prevent plague-induced mortality in prairie dogs and associated species are underway.

  12. Grazing exit versus grazing incidence geometry for x-ray absorption near edge structure analysis of arsenic traces

    International Nuclear Information System (INIS)

    Meirer, F.; Streli, C.; Wobrauschek, P.; Zoeger, N.; Pepponi, G.

    2009-01-01

    In the presented study the grazing exit x-ray fluorescence was tested for its applicability to x-ray absorption near edge structure analysis of arsenic in droplet samples. The experimental results have been compared to the findings of former analyses of the same samples using a grazing incidence (GI) setup to compare the performance of both geometries. Furthermore, the investigations were accomplished to gain a better understanding of the so called self-absorption effect, which was observed and investigated in previous studies using a GI geometry. It was suggested that a normal incidence-grazing-exit geometry would not suffer from self-absorption effects in x-ray absorption fine structure (XAFS) analysis due to the minimized path length of the incident beam through the sample. The results proved this assumption and in turn confirmed the occurrence of the self-absorption effect for GI geometry. Due to its lower sensitivity it is difficult to apply the GE geometry to XAFS analysis of trace amounts (few nanograms) of samples but the technique is well suited for the analysis of small amounts of concentrated samples

  13. Plague bacterium as a transformer species in prairie dogs and the grasslands of western North America

    Science.gov (United States)

    Eads, David A.; Biggins, Dean E.

    2015-01-01

    Invasive transformer species change the character, condition, form, or nature of ecosystems and deserve considerable attention from conservation scientists. We applied the transformer species concept to the plague bacterium Yersinia pestis in western North America, where the pathogen was introduced around 1900. Y. pestis transforms grassland ecosystems by severely depleting the abundance of prairie dogs (Cynomys spp.) and thereby causing declines in native species abundance and diversity, including threatened and endangered species; altering food web connections; altering the import and export of nutrients; causing a loss of ecosystem resilience to encroaching invasive plants; and modifying prairie dog burrows. Y. pestis poses an important challenge to conservation biologists because it causes trophic-level perturbations that affect the stability of ecosystems. Unfortunately, understanding of the effects of Y. pestis on ecosystems is rudimentary, highlighting an acute need for continued research.

  14. Respiratory isolation for tuberculosis: the experience of Indigenous peoples on the Canadian prairies.

    Science.gov (United States)

    Mayan, M; Robinson, T; Gokiert, R; Tremblay, M; Abonyi, S; Long, R

    2017-12-21

    Setting: The Prairie provinces of Canada. Objective: To understand how Indigenous peoples with infectious pulmonary tuberculosis living in different community settings in the Prairie provinces of Canada experience respiratory isolation. Design: Using an exploratory qualitative approach, we interviewed participants living in urban centres, non-remote reserve settings and remote and isolated reserve settings. Results: Through qualitative content analysis of 48 interviews, we determined that participants experienced feelings of confinement regardless of the community setting in which they lived. Participants also experienced family and social disconnect, but the experience was more potent for the remote and isolated reserve participants, who were required to be flown out of their home communities to receive treatment, and for those urban centre and non-remote reserve participants who lacked social connections. The roles of past experiences with sanitoria and of family in providing social support are discussed. Conclusions: The conclusions of this study focus on examining isolation policies and improving the hospital isolation experience.

  15. Plague bacterium as a transformer species in prairie dogs and the grasslands of western North America.

    Science.gov (United States)

    Eads, David A; Biggins, Dean E

    2015-08-01

    Invasive transformer species change the character, condition, form, or nature of ecosystems and deserve considerable attention from conservation scientists. We applied the transformer species concept to the plague bacterium Yersinia pestis in western North America, where the pathogen was introduced around 1900. Y. pestis transforms grassland ecosystems by severely depleting the abundance of prairie dogs (Cynomys spp.) and thereby causing declines in native species abundance and diversity, including threatened and endangered species; altering food web connections; altering the import and export of nutrients; causing a loss of ecosystem resilience to encroaching invasive plants; and modifying prairie dog burrows. Y. pestis poses an important challenge to conservation biologists because it causes trophic-level perturbations that affect the stability of ecosystems. Unfortunately, understanding of the effects of Y. pestis on ecosystems is rudimentary, highlighting an acute need for continued research. © 2015 Society for Conservation Biology.

  16. Implementation of an advanced digital feedwater control system at the Prairie Island nuclear generating station

    International Nuclear Information System (INIS)

    Paris, R.E.; Gaydos, K.A.; Hill, J.O.; Whitson, S.G.; Wirkkala, R.

    1990-05-01

    EPRI Project RP2126-4 was a cooperative effort between TVA, EPRI, and Westinghouse which resulted in the demonstration of a prototype of a full range, fully automatic feedwater control system, using fault tolerant digital technology, at the TVA Sequoyah simulator site. That prototype system also included advanced signal validation algorithms and an advanced man-machine interface that used CRT-based soft-control technology. The Westinghouse Advanced Digital Feedwater Control System (ADFCS) upgrade, which contains elements that were part of that prototype system, has since been installed at Northern States Power's Prairie Island Unit 2. This upgrade was very successful due to the use of an advanced control system design and the execution of a well coordinated joint effort between the utility and the supplier. The project experience is documented in this report to help utilities evaluate the technical implications of such a project. The design basis of the Prairie Island ADFCS signal validation for input signal failure fault tolerance is outlined first. Features of the industry-proven system control algorithms are then described. Pre-shipment hardware-in-loop and factory acceptance testing of the Prairie Island system are summarized. Post-shipment site testing, including preoperational and plant startup testing, is also summarized. Plant data from the initial system startup is included. The installation of the Prairie Island ADFCS is described, including both the feedwater control instrumentation and the control board interface. Modification of the plant simulator and operator and I ampersand C personnel training are also discussed. 6 refs., 14 figs., 3 tabs

  17. Exudate Chemical Profiles Derived from Lespedeza and Other Tallgrass Prairie Plant Species

    Science.gov (United States)

    2017-05-01

    Chemical Profiles Derived from Lespedeza and Other Tall- grass Prairie Plant Species. ERDC TN-17-1. Vicksburg, MS: U.S. Army Engineer Re- search and...200-1-52. Washington, DC: U.S. Army Corps of Engineers Headquarters, Civil Works. https://www.wbdg.org/ffc/army-coe/public-works-technical-bulletins...ERDC TN-17-1 May 2017 Approved for public release; distribution is unlimited. Exudate Chemical Profiles Derived from Lespedeza and Other

  18. Alcohol’s Effects on Pair-Bond Maintenance in Male Prairie Voles

    Directory of Open Access Journals (Sweden)

    Andre T. Walcott

    2017-11-01

    Full Text Available Alcohol abuse can have devastating effects on social relationships. In particular, discrepant patterns of heavy alcohol consumption are associated with increased rates of separation and divorce. Previous studies have attempted to model these effects of alcohol using socially monogamous prairie voles. These studies showed that alcohol consumption can inhibit the formation of pair bonds in this species. While these findings indicated that alcohol’s effects on social attachments can involve biological mechanisms, the formation of pair bonds does not properly model long-term human attachments. To overcome this caveat, this study explored whether discordant or concordant alcohol consumption between individuals within established pairs affects maintenance of pair bonds in male prairie voles. Male and female prairie voles were allowed to form a pair bond for 1 week. Following this 1-week cohabitation period, males received access to 10% continuous ethanol; meanwhile, their female partners had access to either alcohol and water or just water. When there was a discrepancy in alcohol consumption, male prairie voles showed a decrease in partner preference (PP. Conversely, when concordant drinking occurred, males showed no inhibition in PP. Further analysis revealed a decrease in oxytocin immunoreactivity in the paraventricular nucleus of alcohol-exposed males that was independent of the drinking status of their female partners. On the other hand, only discordant alcohol consumption resulted in an increase of FosB immunoreactivity in the periaqueductal gray of male voles, a finding suggesting a potential involvement of this brain region in the effects of alcohol on maintenance of pair bonds. Our studies provide the first evidence that alcohol has effects on established pair bonds and that partner drinking status plays a large role in these effects.

  19. Widespread use and frequent detection of neonicotinoid insecticides in wetlands of Canada's Prairie Pothole Region.

    Directory of Open Access Journals (Sweden)

    Anson R Main

    Full Text Available Neonicotinoids currently dominate the insecticide market as seed treatments on Canada's major Prairie crops (e.g., canola. The potential impact to ecologically significant wetlands in this dominantly agro-environment has largely been overlooked while the distribution of use, incidence and level of contamination remains unreported. We modelled the spatial distribution of neonicotinoid use across the three Prairie Provinces in combination with temporal assessments of water and sediment concentrations in wetlands to measure four active ingredients (clothianidin, thiamethoxam, imidacloprid and acetamiprid. From 2009 to 2012, neonicotinoid use was increasing; by 2012, applications covered an estimated ∼11 million hectares (44% of Prairie cropland with >216,000 kg of active ingredients. Thiamethoxam, followed by clothianidin, were the dominant seed treatments by mass and area. Areas of high neonicotinoid use were identified as high density canola or soybean production. Water sampled four times from 136 wetlands (spring, summer, fall 2012 and spring 2013 across four rural municipalities in Saskatchewan similarly revealed clothianidin and thiamethoxam in the majority of samples. In spring 2012 prior to seeding, 36% of wetlands contained at least one neonicotinoid. Detections increased to 62% in summer 2012, declined to 16% in fall, and increased to 91% the following spring 2013 after ice-off. Peak concentrations were recorded during summer 2012 for both thiamethoxam (range:

  20. Widespread use and frequent detection of neonicotinoid insecticides in wetlands of Canada's Prairie Pothole Region.

    Science.gov (United States)

    Main, Anson R; Headley, John V; Peru, Kerry M; Michel, Nicole L; Cessna, Allan J; Morrissey, Christy A

    2014-01-01

    Neonicotinoids currently dominate the insecticide market as seed treatments on Canada's major Prairie crops (e.g., canola). The potential impact to ecologically significant wetlands in this dominantly agro-environment has largely been overlooked while the distribution of use, incidence and level of contamination remains unreported. We modelled the spatial distribution of neonicotinoid use across the three Prairie Provinces in combination with temporal assessments of water and sediment concentrations in wetlands to measure four active ingredients (clothianidin, thiamethoxam, imidacloprid and acetamiprid). From 2009 to 2012, neonicotinoid use was increasing; by 2012, applications covered an estimated ∼11 million hectares (44% of Prairie cropland) with >216,000 kg of active ingredients. Thiamethoxam, followed by clothianidin, were the dominant seed treatments by mass and area. Areas of high neonicotinoid use were identified as high density canola or soybean production. Water sampled four times from 136 wetlands (spring, summer, fall 2012 and spring 2013) across four rural municipalities in Saskatchewan similarly revealed clothianidin and thiamethoxam in the majority of samples. In spring 2012 prior to seeding, 36% of wetlands contained at least one neonicotinoid. Detections increased to 62% in summer 2012, declined to 16% in fall, and increased to 91% the following spring 2013 after ice-off. Peak concentrations were recorded during summer 2012 for both thiamethoxam (range: Wetlands situated in barley, canola and oat fields consistently contained higher mean concentrations of neonicotinoids than in grasslands, but no individual crop singularly influenced overall detections or concentrations. Distribution maps indicate neonicotinoid use is increasing and becoming more widespread with concerns for environmental loading, while frequently detected neonicotinoid concentrations in Prairie wetlands suggest high persistence and transport into wetlands.

  1. The relative contribution of climate to changes in lesser prairie-chicken abundance

    Science.gov (United States)

    Ross, Beth E.; Haukos, David A.; Hagen, Christian A.; Pitman, James

    2016-01-01

    Managing for species using current weather patterns fails to incorporate the uncertainty associated with future climatic conditions; without incorporating potential changes in climate into conservation strategies, management and conservation efforts may fall short or waste valuable resources. Understanding the effects of climate change on species in the Great Plains of North America is especially important, as this region is projected to experience an increased magnitude of climate change. Of particular ecological and conservation interest is the lesser prairie-chicken (Tympanuchus pallidicinctus), which was listed as “threatened” under the U.S. Endangered Species Act in May 2014. We used Bayesian hierarchical models to quantify the effects of extreme climatic events (extreme values of the Palmer Drought Severity Index [PDSI]) relative to intermediate (changes in El Niño Southern Oscillation) and long-term climate variability (changes in the Pacific Decadal Oscillation) on trends in lesser prairie-chicken abundance from 1981 to 2014. Our results indicate that lesser prairie-chicken abundance on leks responded to environmental conditions of the year previous by positively responding to wet springs (high PDSI) and negatively to years with hot, dry summers (low PDSI), but had little response to variation in the El Niño Southern Oscillation and the Pacific Decadal Oscillation. Additionally, greater variation in abundance on leks was explained by variation in site relative to broad-scale climatic indices. Consequently, lesser prairie-chicken abundance on leks in Kansas is more strongly influenced by extreme drought events during summer than other climatic conditions, which may have negative consequences for the population as drought conditions intensify throughout the Great Plains.

  2. GIS habitat analysis for lesser prairie-chickens in southeastern New Mexico

    OpenAIRE

    Johnson, Kristine; Neville, Teri B; Neville, Paul

    2006-01-01

    Abstract Background We conducted Geographic Information System (GIS) habitat analyses for lesser prairie-chicken (LPCH, Tympanuchus pallidicinctus) conservation planning. The 876,799 ha study area included most of the occupied habitat for the LPCH in New Mexico. The objectives were to identify and quantify: 1. suitable LPCH habitat in New Mexico, 2. conversion of native habitats, 3. potential for habitat restoration, and 4. unsuitable habitat available for oil and gas activities. Results We f...

  3. Interannual water-level fluctuations and the vegetation of prairie potholes: Potential impacts of climate change

    Science.gov (United States)

    van der Valk, Arnold; Mushet, David M.

    2016-01-01

    Mean water depth and range of interannual water-level fluctuations over wet-dry cycles in precipitation are major drivers of vegetation zone formation in North American prairie potholes. We used harmonic hydrological models, which require only mean interannual water depth and amplitude of water-level fluctuations over a wet–dry cycle, to examine how the vegetation zones in a pothole would respond to small changes in water depth and/or amplitude of water-level fluctuations. Field data from wetlands in Saskatchewan, North Dakota, and South Dakota were used to parameterize harmonic models for four pothole classes. Six scenarios in which small negative or positive changes in either mean water depth, amplitude of interannual fluctuations, or both, were modeled to predict if they would affect the number of zones in each wetland class. The results indicated that, in some cases, even small changes in mean water depth when coupled with a small change in amplitude of water-level fluctuations can shift a prairie pothole wetland from one class to another. Our results suggest that climate change could alter the relative proportion of different wetland classes in the prairie pothole region.

  4. Functional consequences of climate change-induced plant species loss in a tallgrass prairie.

    Science.gov (United States)

    Craine, Joseph M; Nippert, Jesse B; Towne, E Gene; Tucker, Sally; Kembel, Steven W; Skibbe, Adam; McLauchlan, Kendra K

    2011-04-01

    Future climate change is likely to reduce the floristic diversity of grasslands. Yet the potential consequences of climate-induced plant species losses for the functioning of these ecosystems are poorly understood. We investigated how climate change might alter the functional composition of grasslands for Konza Prairie, a diverse tallgrass prairie in central North America. With species-specific climate envelopes, we show that a reduction in mean annual precipitation would preferentially remove species that are more abundant in the more productive lowland positions at Konza. As such, decreases in precipitation could reduce productivity not only by reducing water availability but by also removing species that inhabit the most productive areas and respond the most to climate variability. In support of this prediction, data on species abundance at Konza over 16 years show that species that are more abundant in lowlands than uplands are preferentially reduced in years with low precipitation. Climate change is likely to also preferentially remove species from particular functional groups and clades. For example, warming is forecast to preferentially remove perennials over annuals as well as Cyperaceae species. Despite these predictions, climate change is unlikely to unilaterally alter the functional composition of the tallgrass prairie flora, as many functional traits such as physiological drought tolerance and maximum photosynthetic rates showed little relationship with climate envelope parameters. In all, although climatic drying would indirectly alter grassland productivity through species loss patterns, the insurance afforded by biodiversity to ecosystem function is likely to be sustained in the face of climate change.

  5. Managing prairie dogs by managing plague: a vaccine for the future?

    Science.gov (United States)

    Johnson, Terry B.; Rocke, Tonie E.; Gober, Pete; Van Pelt, Bill E.; Miller, Michael W.; Tripp, Daniel W.; Abbott, Rachel C.; Bergman, David L.

    2014-01-01

    The Black-footed Ferret Recovery Implementation Team Executive Committee is conducting a project to develop,and (hopefully) eventually implement, a plague vaccination program for prairie dogs. The project is a component of the WesternAssociation of Fish and Wildlife Agencies Grasslands Conservation Initiative. An effective, field-worthy vaccine against plaguecould be the biggest breakthrough in recovery efforts for the black-footed ferret since the 1981 rediscovery of wild ferrets nearMeeteetse, Wyoming. If proven efficacious, the vaccine could help agencies and stakeholder cooperators maintain specificpopulations of prairie dogs at robust levels, thus enhancing range-wide conservation of those species, as well recovery of the ferret,while enabling control of other prairie dog populations to resolve site-specific agricultural and human health concerns. The resultsof laboratory and field-testing in the early stages of developing this vaccine are preliminary but mostly encouraging. A plan forbroad-scale application is being developed for possible use when testing has been completed and (if warranted) the vaccine isregistered for governmental use. An overview of all aspects of the project is discussed.

  6. Evaluation of monkeypox virus infection of prairie dogs (Cynomys ludovicianus) using in vivo bioluminescent imaging

    Science.gov (United States)

    Falendysz, Elizabeth A.; Londoño-Navas, Angela M.; Meteyer, Carol U.; Pussini, Nicola; Lopera, Juan G.; Osorio, Jorge E.; Rocke, Tonie E.

    2014-01-01

    Monkeypox (MPX) is a re-emerging zoonotic disease that is endemic in Central and West Africa, where it can cause a smallpox-like disease in humans. Despite many epidemiologic and field investigations of MPX, no definitive reservoir species has been identified. Using recombinant viruses expressing the firefly luciferase (luc) gene, we previously demonstrated the suitability of in vivo bioluminescent imaging (BLI) to study the pathogenesis of MPX in animal models. Here, we evaluated BLI as a novel approach for tracking MPX virus infection in black-tailed prairie dogs (Cynomys ludovicianus). Prairie dogs were affected during a multistate outbreak of MPX in the US in 2003 and have since been used as an animal model of this disease. Our BLI results were compared with PCR and virus isolation from tissues collected postmortem. Virus was easily detected and quantified in skin and superficial tissues by BLI before and during clinical phases, as well as in subclinical secondary cases, but was not reliably detected in deep tissues such as the lung. Although there are limitations to viral detection in larger wild rodent species, BLI can enhance the use of prairie dogs as an animal model of MPX and can be used for the study of infection, disease progression, and transmission in potential wild rodent reservoirs.

  7. Investigation of climate change impacts on Prairie's petroleum industry in Canada

    International Nuclear Information System (INIS)

    Li, J.B.; Huang, G.H.; Chakma, A.; Huang, Y.F.; Zeng, G.M.

    2002-01-01

    Alberta, Saskatchewan, and Manitoba, the three Prairie provinces of Canada, and their economies strongly depend on the petroleum industry. However, climate change may have potential impacts on the sector that could reverberate onto the socio-economic fabric of the provinces. The petroleum industry in the Prairies is faced with a big challenge: how to adapt to the changing climatic conditions so that they maintain or improve their economic and environmental efficiencies. The attitudes of the different stakeholders concerning climate change and the appropriate measures to be implemented by the petroleum industry were obtained through a questionnaire-based survey conducted between February and June 2001. Based on the responses received, a Chi-square statistical test was applied to look at the complex interactions in the results. An analysis of a number of petroleum-related processes and activities vulnerable to climate change was performed. A sound foundation was obtained for the decision-making process on the climate change measures required in the petroleum industry in the Prairies. 14 refs., 7 tabs

  8. Melanocortin Receptor Agonists Facilitate Oxytocin-Dependent Partner Preference Formation in the Prairie Vole.

    Science.gov (United States)

    Modi, Meera E; Inoue, Kiyoshi; Barrett, Catherine E; Kittelberger, Kara A; Smith, Daniel G; Landgraf, Rainer; Young, Larry J

    2015-07-01

    The central melanocortin (MC) system has been widely studied for its effects on food intake and sexual behavior. However, the MC system, and more specifically the MC4 receptor (MC4R), also interacts with neurochemical systems that regulate socioemotional behaviors, including oxytocin (OT) and dopamine. In monogamous prairie voles, OT and dopamine interact to promote partner preference formation, a laboratory measure of an enduring social bond between mates. Here we investigated the effects of MC receptor activation on partner preference formation in prairie voles, as well as the interaction between the MC and OT systems during this process. Peripheral administration of the brain penetrant MC3/4R receptor peptide agonist, Melanotan II (MTII), and the highly selective, small-molecule MC4R agonist, Pf-446687, enhanced partner preference formation in the prairie vole, but not in the non-monogamous meadow vole. MTII-induced partner preferences were enduring, as they were present 1 week after drug manipulation. The prosocial effects of MCR agonists may be mediated, in part, through modulation of OT, as coadministration of an OT receptor antagonist prevented MTII-induced partner preferences. MTII also selectively activated hypothalamic OT neurons and potentiated central OT release. As OT has been shown to enhance some aspects of social cognition in humans, our data suggest that the MC4R may be a viable therapeutic target for enhancing social function in psychiatric disorders, including autism spectrum disorders and schizophrenia, potentially through activation of the OT system.

  9. Partner Loss in Monogamous Rodents: Modulation of Pain and Emotional Behavior in Male Prairie Voles.

    Science.gov (United States)

    Osako, Yoji; Nobuhara, Reiko; Arai, Young-Chang P; Tanaka, Kenjiro; Young, Larry J; Nishihara, Makoto; Mitsui, Shinichi; Yuri, Kazunari

    2018-01-01

    Pain is modulated by psychosocial factors, and social stress-induced hyperalgesia is a common clinical symptom in pain disorders. To provide a new animal model for studying social modulation of pain, we examined pain behaviors in monogamous prairie voles experiencing partner loss. After cohabitation with novel females, males (n = 79) were divided into two groups on the basis of preference test scores. Half of the males of each group were separated from their partner (loss group), whereas the other half remained paired (paired group). Thus, males from both groups experienced social isolation. Open field tests, plantar tests, and formalin tests were then conducted on males to assess anxiety and pain-related behaviors. Loss males showing partner preferences (n = 20) displayed a significant increase in anxiety-related behavior in the open-field test (central area/total distance: 13.65% [1.58%] for paired versus 6.45% [0.87%] for loss; p partner preferences (r = 0.15). Results indicate that social bonds and their disruption, but not social housing without bonding followed by isolation, modulate pain and emotion in male prairie voles. The prairie vole is a useful model for exploring the neural mechanisms by which social relationships contribute to pain and nociceptive processing in humans.

  10. Assessing range-wide habitat suitability for the Lesser Prairie-Chicken

    Science.gov (United States)

    Jarnevich, Catherine S.; Holcombe, Tracy R.; Grisham, Blake A.; Timmer, Jennifer M.; Boal, Clint W.; Butler, Matthew; Pitman, James C.; Kyle, Sean; Klute, David; Beauprez, Grant M.; Janus, Allan; Van Pelt, William E.

    2016-01-01

    Population declines of many wildlife species have been linked to habitat loss incurred through land-use change. Incorporation of conservation planning into development planning may mitigate these impacts. The threatened Lesser Prairie-Chicken (Tympanuchus pallidicinctus) is experiencing loss of native habitat and high levels of energy development across its multijurisdictional range. Our goal was to explore relationships of the species occurrence with landscape characteristics and anthropogenic effects influencing its distribution through evaluation of habitat suitability associated with one particular habitat usage, lekking. Lekking has been relatively well-surveyed, though not consistently, in all jurisdictions. All five states in which Lesser Prairie-Chickens occur cooperated in development of a Maxent habitat suitability model. We created two models, one with state as a factor and one without state. When state was included it was the most important predictor, followed by percent of land cover consisting of known or suspected used vegetation classes within a 5000 m area around a lek. Without state, land cover was the most important predictor of relative habitat suitability for leks. Among the anthropogenic predictors, landscape condition, a measure of human impact integrated across several factors, was most important, ranking third in importance without state. These results quantify the relative suitability of the landscape within the current occupied range of Lesser Prairie-Chickens. These models, combined with other landscape information, form the basis of a habitat assessment tool that can be used to guide siting of development projects and targeting of areas for conservation.

  11. Characterization of the oxytocin system regulating affiliative behavior in female prairie voles.

    Science.gov (United States)

    Ross, H E; Cole, C D; Smith, Y; Neumann, I D; Landgraf, R; Murphy, A Z; Young, L J

    2009-09-15

    Oxytocin regulates partner preference formation and alloparental behavior in the socially monogamous prairie vole (Microtus ochrogaster) by activating oxytocin receptors in the nucleus accumbens of females. Mating facilitates partner preference formation, and oxytocin-immunoreactive fibers in the nucleus accumbens have been described in prairie voles. However, there has been no direct evidence of oxytocin release in the nucleus accumbens during sociosexual interactions, and the origin of the oxytocin fibers is unknown. Here we show for the first time that extracellular concentrations of oxytocin are increased in the nucleus accumbens of female prairie vole during unrestricted interactions with a male. We further show that the distribution of oxytocin-immunoreactive fibers in the nucleus accumbens is conserved in voles, mice and rats, despite remarkable species differences in oxytocin receptor binding in the region. Using a combination of site-specific and peripheral infusions of the retrograde tracer Fluorogold, we demonstrate that the nucleus accumbens oxytocin-immunoreactive fibers likely originate from paraventricular and supraoptic hypothalamic neurons. This distribution of retrogradely labeled neurons is consistent with the hypothesis that striatal oxytocin fibers arise from collaterals of magnocellular neurons of the neurohypophysial system. If correct, this may serve to coordinate peripheral and central release of oxytocin with appropriate behavioral responses associated with reproduction, including pair bonding after mating, and maternal responsiveness following parturition and during lactation.

  12. Uptake of C14-atrazine by prairie grasses in a phytoremediation setting.

    Science.gov (United States)

    Khrunyk, Yuliya; Schiewer, Silke; Carstens, Keri L; Hu, Dingfei; Coats, Joel R

    2017-02-01

    Agrochemicals significantly contribute to environmental pollution. In the USA, atrazine is a widely used pesticide and commonly found in rivers, water systems, and rural wells. Phytoremediation can be a cost-effective means of removing pesticides from soil. The objective of this project was to investigate the ability of prairie grasses to remove atrazine. 14 C-labeled atrazine was added to sterilized sand and water/nutrient cultures, and the analysis was performed after 21 days. Switchgrass and big bluestem were promising species for phytoremediation, taking up about 40% of the applied [ 14 C] in liquid hydroponic cultures, and between 20% and 33% in sand cultures. Yellow Indiangrass showed low resistance to atrazine toxicity and low uptake of [ 14 C] atrazine in liquid hydroponic cultures. Atrazine degradation increased progressively from sand to roots and leaves. Most atrazine taken up by prairie grasses from sand culture was degraded to metabolites, which accounted for 60-80% of [ 14 C] detected in leaves. Deisopropylatrazine (DIA) was the main metabolite detected in sand and roots, whereas in leaves further metabolism took place, forming increased amounts of didealkylatrazine (DDA) and an unidentified metabolite. In conclusion, prairie grasses achieved high atrazine removal and degradation, showing a high potential for phytoremediation.

  13. Direct and indirect responses of tallgrass prairie butterflies to prescribed burning

    Science.gov (United States)

    Vogel, Jennifer A.; Koford, Rolf R.; Debinski, Diane M.

    2010-01-01

    Fire is an important tool in the conservation and restoration of tallgrass prairie ecosystems. We investigated how both the vegetation composition and butterfly community of tallgrass prairie remnants changed in relation to the elapsed time (in months) since prescribed fire. Butterfly richness and butterfly abundance were positively correlated with the time since burn. Habitat-specialist butterfly richness recovery time was greater than 70 months post-fire and habitat-specialist butterfly abundance recovery time was approximately 50 months post-fire. Thus, recovery times for butterfly populations after prescribed fires in our study were potentially longer than those previously reported. We used Path Analysis to evaluate the relative contributions of the direct effect of time since fire and the indirect effects of time since fire through changes in vegetation composition on butterfly abundance. Path models highlighted the importance of the indirect effects of fire on habitat features, such as increases in the cover of bare ground. Because fire return intervals on managed prairie remnants are often less than 5 years, information on recovery times for habitat-specialist insect species are of great importance. ?? 2010 Springer Science+Business Media B.V.

  14. Interactive effects of chemical and biological controls on food-web composition in saline prairie lakes.

    Science.gov (United States)

    Cooper, Ryan N; Wissel, Björn

    2012-11-27

    Salinity is restricting habitatability for many biota in prairie lakes due to limited physiological abilities to cope with increasing osmotic stress. Yet, it remains unclear how salinity effects vary among major taxonomic groups and what role other environmental parameters play in shaping food-web composition. To answer these questions, we sampled fish, zooplankton and littoral macroinvertebrates in 20 prairie lakes (Saskatchewan, Canada) characterized by large gradients in water chemistry and lake morphometry. We showed that salinity thresholds differed among major taxonomic groups, as most fishes were absent above salinities of 2 g L-1, while littoral macroinvertebrates were ubiquitous. Zooplankton occurred over the whole salinity range, but changed taxonomic composition as salinity increased. Subsequently, the complexity of fish community (diversity) was associated with large changes in invertebrate communities. The directional changes in invertebrate communities to smaller taxa indicated that complex fish assemblages resulted in higher predation pressure. Most likely, as the complexity of fish community decreased, controls of invertebrate assemblages shifted from predation to competition and ultimately to productivity in hypersaline lakes. Surprisingly, invertebrate predators did not thrive in the absence of fishes in these systems. Furthermore, the here identified salinity threshold for fishes was too low to be a result of osmotic stress. Hence, winterkill was likely an important factor eliminating fishes in low salinity lakes that had high productivity and shallow water depth. Ultimately, while salinity was crucial, intricate combinations of chemical and biological mechanisms also played a major role in controlling the assemblages of major taxonomic groups in prairie lakes.

  15. Production of germline transgenic prairie voles (Microtus ochrogaster) using lentiviral vectors.

    Science.gov (United States)

    Donaldson, Zoe R; Yang, Shang-Hsun; Chan, Anthony W S; Young, Larry J

    2009-12-01

    The study of alternative model organisms has yielded tremendous insights into the regulation of behavioral and physiological traits not displayed by more widely used animal models, such as laboratory rats and mice. In particular, comparative approaches often exploit species ideally suited for investigating specific phenomenon. For instance, comparative studies of socially monogamous prairie voles and polygamous meadow voles have been instrumental toward gaining an understanding of the genetic and neurobiological basis of social bonding. However, laboratory studies of less commonly used organisms, such as prairie voles, have been limited by a lack of genetic tools, including the ability to manipulate the genome. Here, we show that lentiviral vector-mediated transgenesis is a rapid and efficient approach for creating germline transgenics in alternative laboratory rodents. Injection of a green fluorescent protein (GFP)-expressing lentiviral vector into the perivitelline space of 23 single-cell embryos yielded three live offspring (13 %), one of which (33%) contained germline integration of a GFP transgene driven by the human ubiquitin-C promoter. In comparison, transfer of 23 uninjected embryos yielded six live offspring (26%). Green fluorescent protein is present in all tissues examined and is expressed widely in the brain. The GFP transgene is heritable and stably expressed until at least the F(2) generation. This technology has the potential to allow investigation of specific gene candidates in prairie voles and provides a general protocol to pursue germline transgenic manipulation in many different rodent species.

  16. Density and success of bird nests relative to grazing on western Montana grasslands

    Science.gov (United States)

    Fondell, Thomas F.; Ball, I.J.

    2004-01-01

    Grassland birds are declining at a faster rate than any other group of North American bird species. Livestock grazing is the primary economic use of grasslands in the western United States, but the effects of this use on distribution and productivity of grassland birds are unclear. We examined nest density and success of ground-nesting birds on grazed and ungrazed grasslands in western Montana. In comparison to grazed plots, ungrazed plots had reduced forb cover, increased litter cover, increased litter depth, and increased visual obstruction readings (VOR) of vegetation. Nest density among 10 of 11 common bird species was most strongly correlated with VOR of plots, and greatest nest density for each species occurred where mean VOR of the plot was similar to mean VOR at nests. Additionally, all bird species were relatively consistent in their choice of VOR at nests despite substantial differences in VOR among plots. We suggest that birds selected plots based in part on availability of suitable nest sites and that variation in nest density relative to grazing reflected the effect of grazing on availability of nest sites. Nest success was similar between grazed plots and ungrazed plots for two species but was lower for nests on grazed plots than on ungrazed plots for two other species because of increased rates of predation, trampling, or parasitism by brown-headed cowbirds (Molothrus ater). Other species nested almost exclusively on ungrazed plots (six species) or grazed plots (one species), precluding evaluation of the effects of grazing on nest success. We demonstrate that each species in a diverse suite of ground-nesting birds preferentially used certain habitats for nesting and that grazing altered availability of preferred nesting habitats through changes in vegetation structure and plant species composition. We also show that grazing directly or indirectly predisposed some bird species to increased nesting mortality. Management alternatives that avoid

  17. Traditional cattle grazing in a mosaic alkali landscape: effects on grassland biodiversity along a moisture gradient.

    Directory of Open Access Journals (Sweden)

    Péter Török

    Full Text Available Extensively managed pastures are of crucial importance in sustaining biodiversity both in local- and landscape-level. Thus, re-introduction of traditional grazing management is a crucial issue in grassland conservation actions worldwide. Traditional grazing with robust cattle breeds in low stocking rates is considered to be especially useful to mimic natural grazing regimes, but well documented case-studies are surprisingly rare on this topic. Our goal was to evaluate the effectiveness of traditional Hungarian Grey cattle grazing as a conservation action in a mosaic alkali landscape. We asked the following questions: (i How does cattle grazing affect species composition and diversity of the grasslands? (ii What are the effects of grazing on short-lived and perennial noxious species? (iii Are there distinct effects of grazing in dry-, mesophilous- and wet grassland types? Vegetation of fenced and grazed plots in a 200-ha sized habitat complex (secondary dry grasslands and pristine mesophilous- and wet alkali grasslands was sampled from 2006-2009 in East-Hungary. We found higher diversity scores in grazed plots compared to fenced ones in mesophilous- and wet grasslands. Higher cover of noxious species was typical in fenced plots compared to their grazed counterparts in the last year in every studied grassland type. We found an increasing effect of grazing from the dry- towards the wet grassland types. The year-to-year differences also followed similar pattern: the site-dependent effects were the lowest in the dry grassland and an increasing effect was detected along the moisture gradient. We found that extensive Hungarian Grey cattle grazing is an effective tool to suppress noxious species and to create a mosaic vegetation structure, which enables to maintain high species richness in the landscape. Hungarian Grey cattle can feed in open habitats along long moisture gradient, thus in highly mosaic landscapes this breed can be the most suitable

  18. Using occupancy models to investigate the prevalence of ectoparasitic vectors on hosts: an example with fleas on prairie dogs

    Science.gov (United States)

    Eads, David A.; Biggins, Dean E.; Doherty, Paul F.; Gage, Kenneth L.; Huyvaert, Kathryn P.; Long, Dustin H.; Antolin, Michael F.

    2013-01-01

    Ectoparasites are often difficult to detect in the field. We developed a method that can be used with occupancy models to estimate the prevalence of ectoparasites on hosts, and to investigate factors that influence rates of ectoparasite occupancy while accounting for imperfect detection. We describe the approach using a study of fleas (Siphonaptera) on black-tailed prairie dogs (Cynomys ludovicianus). During each primary occasion (monthly trapping events), we combed a prairie dog three consecutive times to detect fleas (15 s/combing). We used robust design occupancy modeling to evaluate hypotheses for factors that might correlate with the occurrence of fleas on prairie dogs, and factors that might influence the rate at which prairie dogs are colonized by fleas. Our combing method was highly effective; dislodged fleas fell into a tub of water and could not escape, and there was an estimated 99.3% probability of detecting a flea on an occupied host when using three combings. While overall detection was high, the probability of detection was always dogs, flea occupancy was heightened in old/natural colonies of prairie dogs, and on hosts that were in poor condition. Occupancy was initially low in plots with high densities of prairie dogs, but, as the study progressed, the rate of flea colonization increased in plots with high densities of prairie dogs in particular. Our methodology can be used to improve studies of ectoparasites, especially when the probability of detection is low. Moreover, the method can be modified to investigate the co-occurrence of ectoparasite species, and community level factors such as species richness and interspecific interactions.

  19. An adaptive approach to invasive plant management on U.S. Fish and Wildlife Service-owned native prairies in the Prairie Pothole Region: decision support under uncertainity

    Science.gov (United States)

    Gannon, Jill J.; Moore, Clinton T.; Shaffer, Terry L.; Flanders-Wanner, Bridgette

    2011-01-01

    Much of the native prairie managed by the U.S. Fish and Wildlife Service (Service) in the Prairie Pothole Region (PPR) is extensively invaded by the introduced cool-season grasses smooth brome (Bromus inermis) and Kentucky bluegrass (Poa pratensis). The central challenge to managers is selecting appropriate management actions in the face of biological and environmental uncertainties. We describe the technical components of a USGS management project, and explain how the components integrate and inform each other, how data feedback from individual cooperators serves to reduce uncertainty across the whole region, and how a successful adaptive management project is coordinated and maintained on a large scale. In partnership with the Service, the U.S. Geological Survey is developing an adaptive decision support framework to assist managers in selecting management actions under uncertainty and maximizing learning from management outcomes. The framework is built around practical constraints faced by refuge managers and includes identification of the management objective and strategies, analysis of uncertainty and construction of competing decision models, monitoring, and mechanisms for model feedback and decision selection. Nineteen Service field stations, spanning four states of the PPR, are participating in the project. They share a common management objective, available management strategies, and biological uncertainties. While the scope is broad, the project interfaces with individual land managers who provide refuge-specific information and receive updated decision guidance that incorporates understanding gained from the collective experience of all cooperators.

  20. Social isolation disrupts innate immune responses in both male and female prairie voles and enhances agonistic behavior in female prairie voles (Microtus ochrogaster).

    Science.gov (United States)

    Scotti, Melissa-Ann L; Carlton, Elizabeth D; Demas, Gregory E; Grippo, Angela J

    2015-04-01

    Psychosocial stress, specifically social isolation, is an important risk factor for the development of a variety of psychological and physiological disorders. Changes in immune function have been hypothesized to mediate this relationship. The current study used the prairie vole (Microtus ochrogaster) model of isolation-induced depressive-like behavior to test whether social isolation led to changes in innate immune function. Specifically, we used hemolytic complement (CH50) and bacteria killing assays to assess innate immunity, in paired or singly housed male and female prairie voles. Further, in a second experiment we tested whether females exposed to an additional short-term social stressor, a resident-intruder trial, would show changes in immune function as well as enhanced hypothalamic pituitary axis (HPA) activity as indicated by elevated plasma corticosterone levels. Socially isolated animals, regardless of sex, had significantly reduced CH50s and bacteria killing ability. Socially isolated females exposed to a resident-intruder stressor also showed reduced CH50s and bacteria killing ability as well as significant increases in aggressive behavior, however, they did not show elevated circulating corticosterone levels. Collectively, these data will help inform our understanding of the relationship between social isolation and physiological and psychological health. Copyright © 2015 Elsevier Inc. All rights reserved.

  1. Temporal profiles of vegetation indices for characterizing grazing intensity on natural grasslands in Pampa biome

    Directory of Open Access Journals (Sweden)

    Amanda Heemann Junges

    2016-08-01

    Full Text Available ABSTRACT The Pampa biome is an important ecosystem in Brazil that is highly relevant to livestock production. The objective of this study was to analyze the potential use of vegetation indices to discriminate grazing intensities on natural grasslands in the Pampa biome. Moderate Resolution Imaging Spectroradiometer (MODIS Normalized Difference Vegetation Index (NDVI and Enhanced Vegetation Index (EVI images from Jan to Dec, 2000 to 2013 series, were analyzed for natural grassland experimental units managed under high (forage allowance of 5 ± 2 % live weight – LW, moderate (13 ± 5 % LW and low grazing intensity (19 ± 7 % LW. Regardless of intensity, the temporal profiles showed lower NDVI and EVI during winter, increased values in spring because of summer species regrowth, slightly decreased values in summer, especially in years when there is a water deficit, and increased values in the fall associated with the beginning of winter forage development. The average temporal profiles of moderate grazing intensity exhibited greater vegetation index values compared with low and high grazing intensities. The temporal profiles of less vegetation index were associated with lower green biomass accumulation caused by the negative impact of stocking rates on the leaf area index under high grazing intensity and a floristic composition with a predominance of tussocks under low grazing intensity. Vegetation indices can be used for distinguishing moderate grazing intensity from low and high intensities. The average EVI values can discriminate moderate grazing intensity during any season, and the NDVI values can discriminate moderate grazing intensity during spring and winter.

  2. Grazing reduces soil greenhouse gas fluxes in global grasslands: a meta-analysis

    Science.gov (United States)

    Tang, Shiming; Tian, Dashuan; Niu, Shuli

    2017-04-01

    Grazing causes a worldwide degradation in grassland and likely alters soil greenhouse gas fluxes (GHGs). However, the general patterns of grazing-induced changes in grassland soil GHGs and the underlying mechanisms remain unclear. Thus, we synthesized 63 independent experiments in global grasslands that examined grazing impacts on soil GHGs (CO2, CH4 and N2O). We found that grazing with light or moderate intensity did not significantly influence soil GHGs, but consistently depressed them under heavy grazing, reducing CO2 emission by 10.55%, CH4 uptake by 19.24% and N2O emission by 28.04%. The reduction in soil CO2 was mainly due to decreased activity in roots and microbes (soil respiration per unit root and microbial biomass), which was suppressed by less water availability due to higher soil temperature induced by lower community cover under heavy grazing. N2O emission decreased with grazing-caused decline in soil total N. The inhibitory effect on methanotroph activities by water stress is responsible for the decreased CH4 uptake. Furthermore, grazing duration and precipitation also influenced the direction and magnitude of responses in GHGs fluxes. Overall, our results indicate that the reduction in soil CO2 and N2O emission under heavy grazing is partially compensated by the decrease in CH4 uptake, which is mainly regulated by variations in soil moisture.

  3. Mixing Ventilation

    DEFF Research Database (Denmark)

    Kandzia, Claudia; Kosonen, Risto; Melikov, Arsen Krikor

    In this guidebook most of the known and used in practice methods for achieving mixing air distribution are discussed. Mixing ventilation has been applied to many different spaces providing fresh air and thermal comfort to the occupants. Today, a design engineer can choose from large selection...

  4. New insights into the phylogenetics and population structure of the prairie falcon (Falco mexicanus)

    Science.gov (United States)

    Doyle, Jacqueline M.; Bell, Douglas A.; Bloom, Peter H.; Emmons, Gavin; Fesnock, Amy; Katzner, Todd; LePre, Larry; Leonard, Kolbe; SanMiguel, Phillip; Westerman, Rick; DeWoody, J. Andrew

    2018-01-01

    BackgroundManagement requires a robust understanding of between- and within-species genetic variability, however such data are still lacking in many species. For example, although multiple population genetics studies of the peregrine falcon (Falco peregrinus) have been conducted, no similar studies have been done of the closely-related prairie falcon (F. mexicanus) and it is unclear how much genetic variation and population structure exists across the species’ range. Furthermore, the phylogenetic relationship of F. mexicanus relative to other falcon species is contested. We utilized a genomics approach (i.e., genome sequencing and assembly followed by single nucleotide polymorphism genotyping) to rapidly address these gaps in knowledge.ResultsWe sequenced the genome of a single female prairie falcon and generated a 1.17 Gb (gigabases) draft genome assembly. We generated maximum likelihood phylogenetic trees using complete mitochondrial genomes as well as nuclear protein-coding genes. This process provided evidence that F. mexicanus is an outgroup to the clade that includes the peregrine falcon and members of the subgenus Hierofalco. We annotated > 16,000 genes and almost 600,000 high-quality single nucleotide polymorphisms (SNPs) in the nuclear genome, providing the raw material for a SNP assay design featuring > 140 gene-associated markers and a molecular-sexing marker. We subsequently genotyped ~ 100 individuals from California (including the San Francisco East Bay Area, Pinnacles National Park and the Mojave Desert) and Idaho (Snake River Birds of Prey National Conservation Area). We tested for population structure and found evidence that individuals sampled in California and Idaho represent a single panmictic population.ConclusionsOur study illustrates how genomic resources can rapidly shed light on genetic variability in understudied species and resolve phylogenetic relationships. Furthermore, we found evidence of a single, randomly mating

  5. Using digital photography to examine grazing in montane meadows

    Science.gov (United States)

    McIlroy, Susan K.; Allen-Diaz, Barbara H.; Berg, Alexander C.

    2011-01-01

    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.

  6. Annual methane budgets of sheep grazing systems were regulated by grazing intensities in the temperate continental steppe: A two-year case study

    Science.gov (United States)

    Ma, Lei; Zhong, Mengying; Zhu, Yuhao; Yang, Helong; Johnson, Douglas A.; Rong, Yuping

    2018-02-01

    Methane (CH4) emission from animal husbandry accounts for a large percentage of anthropogenic contributions to CH4 emissions. Fully understanding of grazing management effects on the CH4 budget is essential for mitigating CH4 emissions in the temperate grazing steppe systems. Annual CH4 budgets for the sheep grazed steppes at various grazing intensities, un-grazing (UG, 0 sheep ha-1year-1), defer grazing (DG, 1.0 sheep ha-1 year-1), moderate grazing (MG, 1.43 sheep ha-1year-1), and heavy grazing (HG, 2.43 sheep ha-1year-1) were assessed across 2012-2014 in the agro-pastoral region of northern China. Annual soil CH4 uptake averaged across 2012-2014 were 1.1 ± 0.1, 2.4 ± 0.2, 2.2 ± 0.2, and 1.3 ± 0.1 kg CH4-C ha-1 for UG, DG (only 2013-2014), MG and HG sites. Non-growing season CH4 uptake comprised 50.0 ± 4.3% of annual CH4 uptake in 2012-2013 and 37.7 ± 2.0% in 2013-2014. DG and MG significantly promoted annual soil CH4 uptake (P 0.05). Bell-shaped relationship was presented between stocking rates and soil CH4 uptake (r2 = 0.59, P budgets for the grazed grasslands were -1.1 ± 0.1, 5.7 ± 0.6, 11.5 ± 1.5 and 15.5 ± 1.3 kg CH4-C ha-1 year-1 in UG, DG (only 2013-2014), MG and HG across 2012-2014. Soil CH4 uptake could offset 29.7 ± 5.6, 15.9 ± 4.3 and 6.8 ± 1.0% of total annual CH4 emissions from sheep, sheepfold and faeces in DG, MG, and HG. All grazed steppes are sources for atmospheric CH4 and the magnitude is regulated by grazing intensities. Sheep CH4 emissions for 1-g liveweight gain were 0.21, 0.32 and 0.37 g CH4-C in DG, MG and HG, respectively. DG is the recommended grazing management in this region to achieve greater herbage mass, higher sheep performance and lower CH4 emissions simultaneously.

  7. Impact of grazing abandonment on floristic diversity in the priority habitat type *9562 Grecian Juniper Woods

    Science.gov (United States)

    Vrahnakis, Michael; Kazoglou, Yannis; Fotiadis, George; Kakouros, Petros; Nasiakou, Stamatia; Soutsas, Konstantinos

    2017-04-01

    The habitat type *9562 Grecian juniper woods (Juniperetum excelsae) includes Greek juniper (Juniperus excelsa M. Bieb.) forests and they are found mainly in the western sector of the Prespa National Park, NW Greece. Greek juniper forests are considered extremely rare for EU-28, recommending a priority habitat type in accordance with Directive 92/43/EEC. In addition, their ecological importance is great given its high plant taxa richness; they harbor most of the 900 plant taxa found in the western sector of the Park, many of them being important for EU or global scale. The accelerated invasion of deciduous hardwoods is the most significant risk for the habitat, since its rich flora is well-adapted to open light conditions produced by the open spaced Greek junipers. Also, the dense vegetated conditions deprive the regeneration of the photophilous Greek juniper. The invasion results from the lack of its natural controller, i.e. the grazing livestock. It is estimated that the total area of juniper forests for the Devas area decreased to 89% of the area of 1945 in favor of invasive hardwoods. The paper presents the analysis of the floristic diversity of the priority habitat type *9562 Grecian Juniper Woods (Juniperetum excelsae) (GJWs). Four (4) types of juniper forest ranges (GJWs) were distinguished in terms of canopy cover: (a) pure GJWs, (b) mixed open GJWs, (c) open GJWs, and (d) mixed dense GJWs. A total of 171 plant taxa were recorded, and distributed within 43 botanical families; the largest one being Leguminosae (26 taxa). The statistically estimated plant taxa richness for pure GJWs was 116.4, for mixed open 152.6, for open 57.9, and for mixed dense 90.2 taxa. The analysis of α-diversity indices did not reveal any specific trend of diversity for the four GJWs. The behavior of the variability of diversity among the four range types of GJWs was depending on the emphasis the used indices place on properties such as taxa richness or abundance. This fact was

  8. Review of grazing studies on plutonium-contaminated rangelands

    International Nuclear Information System (INIS)

    Smith, D.D.

    1977-01-01

    Literature is cited that has provided data on tissue actinide concentrations in grazing animals when the actinide dosages resulted from artificial administration or from periodic exposure. Only one long-term study is known where a reproducing beef herd was restricted to a plutonium-contaminated environment. Highlights of this study that are reviewed and discussed include: relationship of ingesta concentrations to food habits; tissue concentration related to length of exposure and level of exposure; and the concentration range in various tissues. Emphasis is given to the gonadal concentration which is approximately 25 times that of muscle and blood. Future study plans are also discussed

  9. Vegetation and Grazing in the St. Katherine Protectorate, South ...

    African Journals Online (AJOL)

    5. Grazing pressure. 1. 2. 3. 4. 5. P lant health. Unk . La bita e. Le gu m ino s a e. Co m p o sita e. A m ara nthac ea e. B ora gin ace ae. C h en opo dia c e ae. E u ph orb iac ea e. S cro ph ula ria cea e. A sc lep id ac e ae. C a ry o phy lla cea e. R ese dace ae. C a pp arace ae. Cuc urb ita cea e. Cruc ife rae. Gram inae. U m be.

  10. An Evaluation of Grazing-Incidence Optics for Neutron Imaging

    Science.gov (United States)

    Gubarev, M. V.

    2007-01-01

    The refractive index for most materials is slightly less than unity, which opens an opportunity to develop the grazing incidence neutron imaging optics. The ideal material for the optics would be natural nickel and its isotopes. Marshall Space Flight Center (MSFC) has active development program on the nickel replicated optics for use in x-ray astronomy. Brief status report on the program is presented. The results of the neutron focusing optic test carried by the MSFC team at National Institute of Standards and Technology (NIST) are also presented. Possible applications of the optics are briefly discussed.

  11. Optical design of grazing incidence toroidal grating monochromator

    International Nuclear Information System (INIS)

    Pouey, M.; Howells, M.R.; Takacs, P.Z.

    1982-01-01

    Design rules using geometrical optics and physical optics associated with the phase balancing method are discussed for stigmatic toroidal grazing incidence monochromators. To determine the optical performance of devices involving mirrirs and/or gratings, ray tracing programs using exact geometry are quite widely used. It is then desirable to have some way to infer the practical performance of an instrument from a spot diagram created by tracing a limited number of rays. We propose a first approach to this problem involving an estimation of the geometrical intensity distribution in the image plane and the corresponding line spread function. (orig.)

  12. Ionization by ion impact at grazing incidence on insulator surface

    CERN Document Server

    Martiarena, M L

    2003-01-01

    We have calculated the energy distribution of electrons produced by ionization of the ionic crystal electrons in grazing fast ion-insulator surface collision. The ionized electrons originate in the 2p F sup - orbital. We observe that the binary peak appears as a double change in the slope of the spectra, in the high energy region. The form of the peak is determined by the initial electron distribution and its position will be affected by the binding energy of the 2p F sup - electron in the crystal. This BEP in insulator surfaces will appear slightly shifted to the low energy side with respect the ion-atom one.

  13. Deltamethrin flea-control preserves genetic variability of black-tailed prairie dogs during a plague outbreak

    Science.gov (United States)

    Jones, P.H.; Biggins, D.E.; Eads, D.A.; Eads, S.L.; Britten, H.B.

    2012-01-01

    Genetic variability and structure of nine black-tailed prairie dog (BTPD, Cynomys ludovicianus) colonies were estimated with 15 unlinked microsatellite markers. A plague epizootic occurred between the first and second years of sampling and our study colonies were nearly extirpated with the exception of three colonies in which prairie dog burrows were previously dusted with an insecticide, deltamethrin, used to control fleas (vectors of the causative agent of plague, Yersinia pestis). This situation provided context to compare genetic variability and structure among dusted and non-dusted colonies pre-epizootic, and among the three dusted colonies pre- and post-epizootic. We found no statistical difference in population genetic structures between dusted and non-dusted colonies pre-epizootic. On dusted colonies, gene flow and recent migration rates increased from the first (pre-epizootic) year to the second (post-epizootic) year which suggested dusted colonies were acting as refugia for prairie dogs from surrounding colonies impacted by plague. Indeed, in the dusted colonies, estimated densities of adult prairie dogs (including dispersers), but not juveniles (non-dispersers), increased from the first year to the second year. In addition to preserving BTPDs and many species that depend on them, protecting colonies with deltamethrin or a plague vaccine could be an effective method to preserve genetic variability of prairie dogs. ?? 2011 Springer Science+Business Media B.V.

  14. Valuing ecosystem and economic services across land-use scenarios in the Prairie Pothole Regions of the Dakotas, USA

    Science.gov (United States)

    Gascoigne, William R.; Hoag, Dana; Koontz, Lynne; Tangen, Brian A.; Shaffer, Terry L.; Gleason, Robert A.

    2011-01-01

    This study uses biophysical values derived for the Prairie Pothole Region (PPR) of North and South Dakota, in conjunction with value transfer methods, to assess environmental and economic tradeoffs under different policy-relevant land-use scenarios over a 20-year period. The ecosystem service valuation is carried out by comparing the biophysical and economic values of three focal services (i.e. carbon sequestration, reduction in sedimentation, and waterfowl production) across three focal land uses in the region [i.e. native prairie grasslands, lands enrolled in the Conservation Reserve and Wetlands Reserve Programs (CRP/WRP), and cropland]. This study finds that CRP/WRP lands cannot mitigate (hectare for hectare) the loss of native prairie from a social welfare standpoint. Land use scenarios where native prairie loss was minimized, and CRP/WRP lands were increased, provided the most societal benefit. The scenario modeling projected native prairie conversion to cropland over the next 20 years would result in a social welfare loss valued at over $4 billion when considering the study's three ecosystem services, and a net loss of about $3.4 billion when reductions in commodity production are accounted for.

  15. Age at Vaccination May Influence Response to Sylvatic Plague Vaccine (SPV) in Gunnison's Prairie Dogs (Cynomys gunnisoni).

    Science.gov (United States)

    Rocke, Tonie E; Tripp, Dan; Lorenzsonn, Faye; Falendysz, Elizabeth; Smith, Susan; Williamson, Judy; Abbott, Rachel

    2015-06-01

    Gunnison's prairie dogs (Cynomys gunnisoni) have been considered at greater risk from Yersinia pestis (plague) infection in the montane portion of their range compared to populations at lower elevations, possibly due to factors related to flea transmission of the bacteria or greater host susceptibility. To test the latter hypothesis and determine whether vaccination against plague with an oral sylvatic plague vaccine (SPV) improved survival, we captured prairie dogs from a C. g. gunnisoni or "montane" population and a C. g. zuniensis or "prairie" population for vaccine efficacy and challenge studies. No differences (P = 0.63) were found in plague susceptibility in non-vaccinated animals between these two populations; however, vaccinates from the prairie population survived plague challenge at significantly higher rates (P plague challenge at a much higher rate than adults (P plague in the C. g. gunnisoni or "montane" populations of Gunnison's prairie dogs, and that SPV could be a useful plague management tool for this species, particularly if targeted at younger cohorts.

  16. SEASON OF DELTAMETHRIN APPLICATION AFFECTS FLEA AND PLAGUE CONTROL IN WHITE-TAILED PRAIRIE DOG (CYNOMYS LEUCURUS) COLONIES, COLORADO, USA.

    Science.gov (United States)

    Tripp, Daniel W; Streich, Sean P; Sack, Danielle A; Martin, Daniel J; Griffin, Karen A; Miller, Michael W

    2016-07-01

    In 2008 and 2009, we evaluated the duration of prophylactic deltamethrin treatments in white-tailed prairie dog ( Cynomys leucurus ) colonies and compared effects of autumn or spring dust application in suppressing flea numbers and plague. Plague occurred before and during our experiment. Overall, flea abundance tended to increase from May or June to September, but it was affected by deltamethrin treatment and plague dynamics. Success in trapping prairie dogs (animals caught/trap days) declined between June and September at all study sites. However, by September trap success on dusted sites (19%; 95% confidence interval [CI] 16-22%) was about 15-fold greater than on undusted control sites (1%; CI 0.3-4%; P≤0.0001). Applying deltamethrin dust as early as 12 mo prior seemed to afford some protection to prairie dogs. Our data showed that dusting even a portion of a prairie dog colony can prolong its persistence despite epizootic plague. Autumn dusting may offer advantages over spring in suppressing overwinter or early-spring flea activity, but timing should be adjusted to precede the annual decline in aboveground activity for hibernating prairie dog species. Large colony complexes or collections of occupied but fragmented habitat may benefit from dusting some sites in spring and others in autumn to maximize flea suppression in a portion of the complex or habitat year-round.

  17. Use of vegetation sampling and analysis to detect a problem within a portion of a prairie restoration project.

    Science.gov (United States)

    Franson, Raymond; Scholes, Chad; Krabbe, Stephen

    2017-01-02

    In June 2005, the Department of Energy (DOE) began establishing the 60-ha Howell Prairie around the disposal cell at the DOE Weldon Spring Site (WSS). Prairies were historically present in the area of the site. Quantitative Cover sampling was used to quantify Total Cover, Native Grass Cover, Non-Native Grass Cover, Native Forb Cover, Non-Native Forb Cover, Warm Season (C 4 Grass), Cool Season (C 3 Grass), Perennial Cover and Annual Cover, Litter, and Bare Ground. Four permanent vegetation sampling plots were established. The first 4 years of vegetation measurements at Howell Prairie were made during above-average rainfall years on burned and unburned plots. The fifth-year (2012) vegetation measurements were made after below-average rainfall. Five years of results not only document the consistency of the restoration effort in three areas, but also demonstrate deficiencies in Grass Cover in a fourth area. The results are not only useful for Howell Prairie, but will be useful for restoration work throughout the region. Restoration work suffers from a lack of success monitoring and in this case from a lack of available reference areas. Floristic Quality Indices are used to make qualitative comparisons of the site to Konza Prairie sites.

  18. Age at vaccination may influence response to sylvatic plague vaccine (SPV) in Gunnison’s prairie dogs (Cynomys gunnisoni)

    Science.gov (United States)

    Rocke, Tonie E.; Tripp, Daniel W.; Lorenzsonn, Faye; Falendysz, Elizabeth A.; Smith, Susan; Williamson, Judy L.; Abbott, Rachel C.

    2015-01-01

    Gunnison’s prairie dogs (Cynomys gunnisoni) have been considered at greater risk from Yersinia pestis (plague) infection in the montane portion of their range compared to populations at lower elevations, possibly due to factors related to flea transmission of the bacteria or greater host susceptibility. To test the latter hypothesis and determine whether vaccination against plague with an oral sylvatic plague vaccine (SPV) improved survival, we captured prairie dogs from a C. g. gunnisoni or “montane” population and a C. g. zuniensis or “prairie” population for vaccine efficacy and challenge studies. No differences (P = 0.63) were found in plague susceptibility in non-vaccinated animals between these two populations; however, vaccinates from the prairie population survived plague challenge at significantly higher rates (P age, as the prairie group was much younger on average than the montane group. Vaccinates that were juveniles or young adults survived plague challenge at a much higher rate than adults (P ages. These results suggest that host susceptibility is probably not related to the assumed greater risk from plague in the C. g. gunnisoni or “montane” populations of Gunnison’s prairie dogs, and that SPV could be a useful plague management tool for this species, particularly if targeted at younger cohorts.

  19. Flea abundance, diversity, and plague in Gunnison's prairie dogs (Cynomys gunnisoni) and their burrows in montane grasslands in northern New Mexico

    Science.gov (United States)

    Megan M. Friggens; Robert R. Parmenter; Michael Boyden; Paulette L. Ford; Kenneth Gage; Paul Keim

    2010-01-01

    Plague, a flea-transmitted infectious disease caused by the bacterium Yersinia pestis, is a primary threat to the persistence of prairie dog populations (Cynomys spp.). We conducted a 3-yr survey (2004-2006) of fleas from Gunnison's prairie dogs (Cynomys gunnisoni) and their burrows in montane grasslands in Valles Caldera National Preserve in New Mexico. Our...

  20. Genetic strain and diet effects on grazing behavior, pasture intake, and milk production.

    Science.gov (United States)

    Sheahan, A J; Kolver, E S; Roche, J R

    2011-07-01

    Understanding how dairy cows adjust their grazing behavior in response to feed supplements is important for the development of management strategies that optimize profit from supplementation. New Zealand Holstein-Friesian (HF) cows have been selected for milk production on a predominantly pasture-based diet; in comparison, HF cows of North American (NA) ancestry have been selected almost exclusively for milk yield and fed diets high in nonfiber carbohydrates (NFC). We hypothesized, therefore, that supplementation would have differing effects on grazing behavior, pasture dry matter intake (DMI), and milk production in these genetic strains at peak, mid, and late lactation. A study was conducted over 2 consecutive lactations, with NA and NZ cows randomly allocated at calving to 0, 3, or 6 kg of dry matter/day concentrate plus unrestricted access to pasture. Pasture DMI, milk production, and grazing behavior were recorded at peak, mid, and late lactation. Concentrates were fed in equal amounts at morning and afternoon milking. The NA cows produced more milk and milk components, and had a greater pasture DMI, despite spending less time grazing. Declines in time spent grazing and pasture DMI were associated with increasing concentrate DMI. Grazing behavior following morning supplementation was different from that recorded following afternoon supplementation. Grazing ceased following morning supplementation before rumen fill could be a limiting factor, and the length of the grazing interval was inversely proportional to the amount of concentrate offered; these results suggest that physiological rather than physical stimuli were responsible for grazing cessation. The decrease in time spent grazing with increasing concentrate DMI is consistent with changes in neuroendocrine factors secreted in response to the presence of food in the digestive tract or with circulating products of digestion. After afternoon supplementation, sunset signaled the end of grazing irrespective of