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Sample records for argentine rangelands recovering

  1. GRAZING CAN HELP WESTERN RANGELANDS RECOVER FROM FIRE

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Much of the approximately 153 million acres of sagebrush rangeland in the western United States is at risk of invasion by non-native annual grass invasion, such as cheatgrass, following fire. Livestock grazing has also been suggested to have contributed to exotic annual grass spread. However, the ...

  2. Deforestation of "degraded" rangelands: The Argentine Chaco enters the next stage of the Anthropocene

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Twenty years ago I completed my Master’s work in the Chaco forests of northern Argentina. The native forests are, in fact, rangelands. In addition to livestock grazing, there is timber extraction, wildlife harvest (think tegu lizard cowboy boots), and charcoal production. I took part in a project co...

  3. Rangeland Research Roundup -1

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Welcome to the inaugural edition of “Rangeland Research Roundup”. Please allow me to introduce myself and provide an overview of our rangeland research in this edition. My name is Justin Derner and I have been the Research Leader for the USDA-Agricultural Research Service (ARS), Rangeland Resources...

  4. Rangelands and Grazing

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rangelands are a type of land cover dominated by grasses, grass-like plants, forbs, and shrubs, where the land is managed as a natural ecosystem for multiple uses including wildlife habitat, biodiversity, recreation, and grazing by livestock. The area cover by rangelands is 48.2% of the land surfac...

  5. RANGELAND SEQUESTRATION POTENTIAL ASSESSMENT

    SciTech Connect

    Lee Spangler; George F. Vance; Gerald E. Schuman; Justin D. Derner

    2012-03-31

    Rangelands occupy approximately half of the world's land area and store greater than 10% of the terrestrial biomass carbon and up to 30% of the global soil organic carbon. Although soil carbon sequestration rates are generally low on rangelands in comparison to croplands, increases in terrestrial carbon in rangelands resulting from management can account for significant carbon sequestration given the magnitude of this land resource. Despite the significance rangelands can play in carbon sequestration, our understanding remains limited. Researchers conducted a literature review to identify sustainably management practices that conserve existing rangeland carbon pools, as well as increase or restore carbon sequestration potentials for this type of ecosystem. The research team also reviewed the impact of grazing management on rangeland carbon dynamics, which are not well understood due to heterogeneity in grassland types. The literature review on the impact of grazing showed a wide variation of results, ranging from positive to negative to no response. On further review, the intensity of grazing appears to be a major factor in controlling rangeland soil organic carbon dynamics. In 2003, researchers conducted field sampling to assess the effect of several drought years during the period 1993-2002. Results suggested that drought can significantly impact rangeland soil organic carbon (SOC) levels, and therefore, carbon sequestration. Resampling was conducted in 2006; results again suggested that climatic conditions may have overridden management effects on SOC due to the ecological lag of the severe drought of 2002. Analysis of grazing practices during this research effort suggested that there are beneficial effects of light grazing compared to heavy grazing and non-grazing with respect to increased SOC and nitrogen contents. In general, carbon storage in rangelands also increases with increased precipitation, although researchers identified threshold levels of

  6. Is rangeland agriculture sustainable?

    PubMed

    Heitschmidt, R K; Vermeire, L T; Grings, E E

    2004-01-01

    The objective of this paper is to examine the sustainability of rangeland agriculture (i.e., managed grazing) on a world-wide basis, with a focus on North America. Sustainability is addressed on three fronts: 1) ecological, 2) economic, and 3) social acceptance. Based on previous and on-going research, we suggest that employment of science-based rangeland grazing management strategies and tactics can ensure ecological sustainability. The formidable challenge in employing such technology centers around the need to balance efficiency of solar energy capture and subsequent harvest efficiencies across an array of highly spatially and temporally variable vegetation growing conditions using animals that graze selectively. Failure to meet this fundamental challenge often accelerates rangeland desertification processes, and in some instances, enhances rate and extent of the invasion of noxious weeds. We also suggest that the fundamental reason that ecologically sound grazing management technologies are often not employed in the management of grazed ecological systems is because social values drive management decisions more so than ecological science issues. This is true in both well-developed societies with substantial economic resources and in less-developed societies with few economic resources. However, the social issues driving management are often entirely different, ranging from multiple-use issues in developed countries to human day-to-day survival issues in poorly developed countries. We conclude that the long-term sustainability of rangeland agriculture in 1) developed societies depends on the ability of rangeland agriculturalists to continually respond in a dynamic, positive, proactive manner to ever-changing social values and 2) less-developed societies on their ability to address the ecological and social consequences arising from unsustainable human populations before the adoption of science-based sustainable rangeland management technologies. PMID:15471792

  7. Rangeland decision-making in Wyoming

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rangelands make up much of Wyoming’s diverse landscapes. In fact, around 85% of Wyoming is considered rangeland. So, what exactly is rangeland? Rangelands are a type of land dominated by some mix of mostly native grasses, forbs and shrubs. Some woodlands are considered rangelands too, particularly i...

  8. Cheatgrass and Grazing Rangelands

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Charles Elliot Fleming was one of the first scientists to work on the western range. In 1946 he published a series of questions concerning grazing of the exotic annual cheatgrass (Bromus tectorm), which had invaded millions of acres of the western rangelands. The introduction and subsequent invasi...

  9. Water harvesting applications for rangelands

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Although water harvesting techniques have been used effectively in irrigated agriculture and domestic water supplies, there seems to have been little continued exploitation of the same techniques in arid and semiarid rangeland restoration. A review of the history of rangeland water harvesting allow...

  10. Rangeland Research Roundup - October 2011

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Conducting rangeland research that is relevant for, and can be applied by, land managers is the core foundation for research projects involving the Rangeland Resources Research Unit. We are continually evaluating our research program to determine which research projects are meeting the needs of land...

  11. INDICATORS OF GREAT BASIN RANGELAND HEALTH

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Early-warning indicators of rangeland health can be used to estimate the functional integrity of a site and may allow sustainable management of desert rangelands. The utility of several vegetation canopy-based indicators of rangeland health at 32 Great Basin rangeland locations was investigated. T...

  12. Biodiversity of rangelands

    SciTech Connect

    West, N.E. )

    1993-01-01

    Biodiversity is a multifaceted phenomenon involving the variety of organisms present, the genetic differences among them, and the communities, ecosystems, and landscape patterns in which they occur. Society will increasingly value biodiversity and influence the passage of laws and writing of regulations involving biodiversity which rangeland managers will have to abide by over the coming decades. Even private and developing world rangelands will be affected. While taxonomic knowledge of vertebrates and vascular plants and their abundance, rarity, and distribution, in the developed nations is generally adequate, the same cannot be said of the developing world. Furthermore, adequate knowledge of invertebrates, nonvascular plants, and microbes is deficient everywhere. Although the basis of variation at all higher levels, genetic variation within rangeland species, even the major ones, has barely been assessed. Obtaining statistically adequate data on populations of rare species that are small and secretive is well nigh impossible. There are many means of measuring community diversity, but all of them are value laden. That is, choice of variables to measure and how they are indexed betrays what one considers are important. One should be more forthright in stating to the users the biases of these methods. There are many other, more useful ways to describe community-level diversity besides the traditional focus on species. Ungulate grazing is an important process in many ecosystems. Thus, removal of grazing destabilizes some systems. Livestock grazing will actually increase the chances of survival of some species. Sustainable development will depend on finding balance between use and protection, from range sites to landscapes, and even on a global basis. 120 refs., 5 figs., 1 tab.

  13. Contemporary Argentine Cinema during Neoliberalism

    ERIC Educational Resources Information Center

    Rocha, Carolina

    2009-01-01

    In this article I analyze contemporary Argentine cinematic production assessing the impact of Law 24,377 that was implemented in 1995 and that provided much-needed funds for national productions. By looking at film production and consumption, the emergence of young filmmakers and the performance of both commercial films and those belonging to the…

  14. Mapping rangelands with unmanned aircraft

    Technology Transfer Automated Retrieval System (TEKTRAN)

    At the Jornada Experimental Range in southern New Mexico, ongoing research is aimed at determining the utility of UAS for rangeland mapping and monitoring and developing an operational UAS-based remote sensing program for ecological applications. ...

  15. Whither the Rangeland?: Protection and Conversion in California's Rangeland Ecosystems

    PubMed Central

    Cameron, D. Richard; Marty, Jaymee; Holland, Robert F.

    2014-01-01

    Land use change in rangeland ecosystems is pervasive throughout the western United States with widespread ecological, social and economic implications. In California, rangeland habitats have high biodiversity value, provide significant habitat connectivity and form the foundation for a number of ecosystem services. To comprehensively assess the conservation status of these habitats, we analyzed the extent and drivers of habitat loss and the degree of protection against future loss across a 13.5 M ha study area in California. We analyzed rangeland conversion between 1984 and 2008 using time series GIS data and classified resulting land uses with aerial imagery. In total, over 195,000 hectares of rangeland habitats were converted during this period. The majority of conversions were to residential and associated commercial development (49% of the area converted), but agricultural intensification was surprisingly extensive and diverse (40% across six categories). Voluntary enrollment in an agricultural tax incentive program provided widespread protection from residential and commercial conversions across 37% of the remaining rangeland habitat extent (7.5 M ha), though this program did not protect rangeland from conversion to more intensive agricultural uses. Additionally, 24% of the remaining rangeland was protected by private conservation organizations or public agencies through land or easement ownership while 38% had no protection status at all. By developing a spatial method to analyze the drivers of loss and patterns of protection, this study demonstrates a novel approach to prioritize conservation strategies and implementation locations to avert habitat conversion. We propose that this approach can be used in other ecosystem types, and can serve as a regional conservation baseline assessment to focus strategies to effect widespread, cost-effective conservation solutions. PMID:25141171

  16. Rangeland monitoring with unmanned aerial vehicles (UAVs)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Unmanned aerial vehicles (UAVs) have great potential for rangeland management applications, such as monitoring vegetation change, developing grazing strategies, determining rangeland health, and assessing remediation treatment effectiveness. UAVs have several advantages: they can be deployed quickly...

  17. A rangeland hydrology and erosion model

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Soil loss rates on rangelands are considered one of the few quantitative indicators for assessing rangeland health and conservation practice effectiveness. An erosion model to predict soil loss specific for rangeland applications is needed because existing erosion models were developed from cropland...

  18. Modeling overland erosion on disturbed rangeland

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Rangeland Hydrology and Erosion Model (RHEM) is a new process-based model developed by the USDA-ARS primarily for undisturbed rangeland. Greater sediment detachment rates are usually generated by concentrated flow rather than by sheet flow. Disturbance on rangeland such as fire and tree encroach...

  19. Selection of the Argentine indicator region

    NASA Technical Reports Server (NTRS)

    Ramirez, C. J.; Reed, C. R. (Principal Investigator)

    1982-01-01

    Determined from available Argentine crop statistics, selection of the Indicator Region was based on the highest wheat, corn, and soybean producing provinces, which were: Buenos Aires, Cordoba, Entre Rios, and Santa Fe. Each province in Argentina was examined for the availability of LANDSAT data; area, yield and production statistics; crop calendars; and other ancillary data. The Argentine Indicator Region is described.

  20. Grasslands, Rangelands, and Agricultural Systems

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sustainable agro-ecosystems are those systems whose production does not negatively affect energy flow, nutrient cycling or ecosystem services. We examined literature reports in each of these different arenas to determine if cellulosic biomass production in rangelands met these criteria. We focused...

  1. Rangelands: a closing carbon sink?

    NASA Astrophysics Data System (ADS)

    Kuhn, Nikolaus J.

    2016-04-01

    Two thirds of the world's agricultural land is suitable for grazing only. Much of this land has experienced severe erosion due to mismanagement, massive redistribution of soil and sediment, and significant degradation of vegetation. As a consequence, geochemical cycles have changed. Unlike croplands, the impact of degradation on nutrient fluxes is hardly compensated on rangelands, potentially disturbing the carbon cycle because of the declining biomass production and the subsequent conversion of litter into soil organic matter. Over time, the degradation leads to a decline in soil C stocks and, if associated with soil erosion, also to a decline in carbon transfer from soil into sediment sinks. A priory reasoning suggests that during the degradation process, with soil productivity not yet massively affected, the Carbon transfer initially increases because soil erosion rates are also greater than in the non-disturbed system. With most soil degradation in rangelands occurring during the past 200 years, this mechanism on a large part of the global land area could have generated an unintentional terrestrial carbon sink during a time period with increasing industrial CO2 emissions. Using global data on soil degradation, soil erosion, soil carbon stocks and dynamics to simulate their interaction and potential role for rangeland carbon cycles supports the assumption that rangelands may have functioned as a carbon sink, but reveals major uncertainties with regards to the size. This highlights the need to improve our knowledge and understanding of rangeland erosion, landscape change and soil formation, both with regards to the recent past, but also the impacts of their future use and climate.

  2. LOCALIZING THE RANGELAND HEALTH METHOD FOR SOUTHEASTERN ARIZONA

    EPA Science Inventory

    The interagency manual Interpreting Indicators of Rangeland Health, Version 4 (Technical Reference 1734-6) provides a method for making rangeland health assessments. The manual recommends that the rangeland health assessment approach be adapted to local conditions. This technica...

  3. Trap-mulching Argentine ants.

    PubMed

    Silverman, Jules; Sorenson, Clyde E; Waldvogel, Michael G

    2006-10-01

    Argentine ant, Linepithema humile (Mayr), management is constrained, in large part, by polydomy where nestmates are distributed extensively across urban landscapes, particularly within mulch. Management with trap-mulching is a novel approach derived from trap-cropping where ants are repelled from a broad domain of nest sites to smaller defined areas, which are subsequently treated with insecticide. This concept was field-tested with mulch surrounding ornamental trees replaced with a narrow band of pine (Pinus spp.) needle mulch (trap) within a much larger patch of repellent aromatic cedar (Juniperus spp.) mulch. After ants reestablished around the trees, the pine needle mulch band was treated with 0.06% fipronil (Termidor). Poor results were obtained when the trap extended from the tree trunk to the edge of the mulched area. When the trap was applied as a circular band around the tree trunk reductions in the number of foraging ants were recorded through 14 d compared with an untreated mulch control, but not for longer periods. Reductions in the number of ant nests within mulch were no different between the trap mulch and any of the other treatments. We conclude that trap-mulching offers limited benefits, and that successful management of Argentine ants will require implementation of complementary or perhaps alternative strategies. PMID:17066809

  4. Developing the 18th indicator for interpreting indicators of rangeland health on Northern Great Plains rangelands

    Technology Transfer Automated Retrieval System (TEKTRAN)

    National Resources Inventory (NRI) resource assessment report shows little to no departure on Rangeland Health for most Northern Great Plains Rangelands. This information is supported by Interpreting Indicators of Rangeland Health (IIRH) data collected at local to regional scales. There is however a...

  5. Rangeland research: strategies for providing sustainability and stewardship to the rangelands of the world

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rangeland research is an important determinant of how rangelands are and will be used. Although larger external forces such as national and global economies and social and political attitudes have direct impact on uses of rangelands, the methods by which we implement and evaluate those economic and...

  6. Agriculture, Forestry and Rangeland Resources

    NASA Technical Reports Server (NTRS)

    Poulton, C. E.

    1973-01-01

    The application of ERTS-1 imagery for providing information on agriculture, forestry, and rangeland resources is described. The use of the ERTS-1 system for stratification and sampling estimates of relatively small areas is discussed. Examples of maps to improve resource definition for land use planning, resource allocation, and resource development are provided. Inventories of various crops, as determined by photointerpretation of ERTS imagery are submitted in tabular form.

  7. [Theory of Argentine cultural "isoidia"].

    PubMed

    Pagés Larraya, F

    1982-03-01

    For the epidemiological study of mental pathology in the Argentine Republic the country has been systematically divided into 25 Cultural Areas, to which it is necessary to add the "megalopolis" of Buenos Aires City and conurbation. Each one of these Cultural Areas is analysed according to the anthropological method, which enables us to comprise an innumerable series of epidemiological variants. We investigate, for example, in every one of them the situation of the mentally sick within the community and the cultural attitude of the latter towards mental illness. For statistical purposes of Psychiatrical Epidemiology an experimental study of the prevalence of this type of disease is carried out in each of the above mentioned areas. As a complement to this investigation an analysis of the Institutional Prevalence of Mental Pathology has been performed, i.e., of the patients attended at the State Establishments, be they national, provincial or municipal. PMID:7136824

  8. Rangeland sequestration potential assessment (Final Report)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rangelands occupy approximately half of the world's land area and store greater than 10% of the terrestrial biomass carbon and up to 30% of the global soil organic carbon. Although soil carbon sequestration rates are generally low on rangelands in comparison to croplands, increases in terriestrial c...

  9. CARBON FLUXES ON NORTH AMERICAN RANGELANDS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Seasonal patterns of growth and thus carbon uptake are relevant to both scientists who study ecosystem properties and managers who strive to maintain rangeland productivity. We studied seasonal patterns of net ecosystem exchange of carbon (NEE) on 11 US rangelands over a 6-year period. All sites w...

  10. Monitoring response to disturbance in dynamic rangelands

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Arid and semi-arid rangelands worldwide provide important ecosystem services and see a diversity of land uses. To maintain the health of these lands, it is necessary to monitor rangeland conditions in response to management and disturbance. Spatial patterns from disturbance are superimposed on patte...

  11. Automated Geospatial Watershed Assessment Tool for Rangelands

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Soil and water conservation is the keystone to sustainable livestock grazing and maintenance of native species on our western rangelands. Good rangeland management requires the ability to assess the potential impacts of climate and management actions on runoff and erosion at both hillslope and wate...

  12. Applying animal behavior to arid rangeland mangement

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Livestock production is one of many demands placed on today’s arid rangelands. Therefore, understanding plant and animal biology and their effects on biotic and abiotic landscape components is fundamental if rangelands are to remain ecologically sustainable. One limiting factor to accomplishing posi...

  13. Monitoring Rangeland Health by Remote Sensing

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Based on a land-cover classification from NASA’s MODerate resolution Imaging Spectroradiometer (MODIS), rangelands cover 48% of the Earth’s land surface, not including Antarctica. Nearly all analyses imply the most economical means of monitoring large areas of rangelands worldwide is with remote s...

  14. Meeting wild bees' needs on rangelands

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Some arid rangeland regions, notably those with warm dry climates of the temperate zones, host great diversities of native bees, primarily non-social species among which are many floral specialists. Rangeland bee faunas are threatened indirectly by invasive exotic weeds wherever these displace nat...

  15. Multiple Scale Remote Sensing for Monitoring Rangelands

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Based on a land-cover classification from NASA’s MODerate resolution Imaging Spectroradiometer (MODIS), rangelands cover 48% of the Earth’s land surface, not including Antarctica. Nearly all analyses imply the most economical means of monitoring large areas of rangelands worldwide is with remote se...

  16. Automated Geospatial Waershed Asessment Tool for Rangelands

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Soil and water conservation is the keystone to sustainable livestock grazing and maintenance of native species on our western rangelands. Good rangeland management requires the ability to assess the potential impacts of climate and management actions on runoff and erosion at both hillslope and water...

  17. Valuation of rangeland ecosystem services

    USGS Publications Warehouse

    Gascoigne, W.R.

    2011-01-01

    Economic valuation lends itself well to the anthropocentric orientation of ecosystem services. An economic perspective on ecosystems portrays them as natural assets providing a flow of goods and services valuable to individuals and society collectively. A few examples include the purification of drinking water, reduced risk from flooding and other extreme events, pollination of agricultural crops, climate regulation, and recreation opportunities from plant and animal habitat maintenance, among many others. Once these goods and services are identified and quantified, they can be monetized to complete the valuation process. The monetization of ecosystem goods and services (in the form of dollars) provides a common metric that allows for cross-comparison of attributes and evaluation of differing ecological scenarios. Complicating the monetization process is the fact that most of these goods and services are public and non-market in nature; meaning they are non-rival and non-exclusive and are typically not sold in a traditional market setting where monetary values are revealed. Instead, one must employ non-market valuation techniques, with primary valuation methods typically being very time and resource consuming, intimidating to non-economists, and often impractical. For these reasons, benefit transfer methods have gained popularity. This methodology harnesses the primary collection results of existing studies to make inferences about the economic values of non-market goods and services at an alternative policy site (in place and/or in time). For instance, if a primary valuation study on oak reestablishment on rangelands in southern California yielded a value of $30 per-acre associated with water regulation, this result can be transferred, with some adjustments, to say something about the value of an acre of oaks on rangelands in northern portions of the state. The economic valuation of rangeland ecosystem services has many roles. Economic values may be used as input

  18. Meadow degradation, hydrological processes and rangeland management in Tibet

    NASA Astrophysics Data System (ADS)

    He, Siyuan; Richards, Keith

    2013-04-01

    Alpine meadow dominated by species of Kobresia is widely distributed in the Tibetan Plateau. Kobresia pygmaea is often a main species and the meadow has evolved as a result of long-term trampling, being a main rangeland resource for livestock grazing. This alpine meadow also plays an important role in regulating the water and energy balance through land-atmosphere interaction, leaving an impact on local hydrological processes and beyond. Therefore, alpine meadow degradation is detrimental to both the health of the ecosystems, and to pastoralism. This research therefore studies the hydrological process with regard to degradation of Kobresia pygmaea meadow, tracing the possible causes, detecting the impacts on soil and biological properties, and further considering the herders' role in future rangeland management. The study area is around the Kema village of the Nagqu Prefecture in Northern Tibet, where human population depends on livestock grazing for livelihood. Main driving factors of alpine meadow degradation are climatic variations and human disturbance. The periodical change in local climate may be related to quasi-oscillatory atmospheric circulations in this monsoon dominated area and the climatic trends with extreme weather conditions can make the whole system hard to recover. Along with climatic variations, overgrazing is predominant with an exceeding of the carrying capacity by almost every household in this village. This is related to the change of rangeland management by the policies of privatisation of pasture and sedentarisation. The acceleration of degradation since the 1980s results in a series of distinct soil-vegetation combination classified in this research as the normal meadow, compact crust and bare soil. The species composition, soil physical and chemical properties and the vertical water movement along the soil-plant-atmosphere continuum are significantly different at the sites representing stages of degradation, revealed by multiple methods

  19. Revegetating sagebrush rangelands invaded by medusahead

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The objectives of this study were to determine: 1) effective treatments for controlling medusahead and 2) the appropriate plant materials for revegetating medusahead-invaded rangelands. Initial treatments of prescribed burning immediately followed with applications of the preemergent herbicide imaza...

  20. Aerospace video imaging systems for rangeland management

    NASA Technical Reports Server (NTRS)

    Everitt, J. H.; Escobar, D. E.; Richardson, A. J.; Lulla, K.

    1990-01-01

    This paper presents an overview on the application of airborne video imagery (VI) for assessment of rangeland resources. Multispectral black-and-white video with visible/NIR sensitivity; color-IR, normal color, and black-and-white MIR; and thermal IR video have been used to detect or distinguish among many rangeland and other natural resource variables such as heavy grazing, drought-stressed grass, phytomass levels, burned areas, soil salinity, plant communities and species, and gopher and ant mounds. The digitization and computer processing of VI have also been demonstrated. VI does not have the detailed resolution of film, but these results have shown that it has considerable potential as an applied remote sensing tool for rangeland management. In the future, spaceborne VI may provide additional data for monitoring and management of rangelands.

  1. Climate change mitigation and adaptation in rangelands

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rangeland ecosystems are multifaceted biophysical systems with highly variable soils, weather, landforms, animals, and vegetation that are manifest in complex management options which involve diverse human goals, values, beliefs and decision-making strategies. Overlaying this vast background variabi...

  2. Revegetating sagebrush rangelands invaded by medusahead

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The objectives of this study are to determine: 1) effective treatments for controlling medusahead and 2) the appropriate plant materials for revegetating medusahead-invaded rangelands. Initial treatments of prescribed burning immediately followed with applications of the preemergent herbicide imazap...

  3. Rehabilitation of degraded rangelands: lessons learned

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The introduction and subsequent invasion of cheatgrass (Bromus tectorum) has had astronomical effects to Great Basin rangelands. Cheatgrass has truncated secondary succession by outcompeting native plant species for limited resources, thus building persistent seed banks that take advantage of condi...

  4. RANGELAND COMMUNITIES: STRUCTURE, FUNCTION, AND CLASSIFICATION

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Determining the vegetational attributes of rangelands is critical to their management. Yet incorporating vegetation structure, function, and classification into a single chapter is an ambitious goal and an attempt to blur the boundaries between classical community ecology that characterize patterns...

  5. RANGELAND NUTRITIONAL PATTERNS AND CATTLE DISTRIBUTION

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Several animal and environmental characteristics affect livestock distribution on rangelands. An understanding of mechanisms governing livestock distribution can help land and livestock managers avoid or ameliorate potential deleterious grazing effects. This research tested hypotheses that foragin...

  6. [Potential emigration of young Italian-Argentines].

    PubMed

    Cacopardo, M C

    1992-12-01

    The author examines trends in out-migration among young, highly skilled Argentines, with a focus on those of Italian descent. Data are from interviews conducted among young adults in Buenos Aires, Mar del Plata, and Rosario. Major factors influencing migration include perceived labor force and economic opportunities. (SUMMARY IN ENG) PMID:12344794

  7. Radiation Studies with Argentine Ion Exchange Material

    SciTech Connect

    Crawford, C.L.

    2002-06-28

    A recent technology exchange between Argentina Nuclear Energy Commission (CNEA) and the US Department of Energy involved vitrification studies of ion exchange resins. Details of the spent ion exchange resins currently stored at two Argentine nuclear power plants, Atucha I and Embalse, have been presented in earlier reports. The present study examines irradiation of simulant samples of ion exchange resins.

  8. USDA internet tool to estimate runoff and soil loss on rangelands: rangelands hydrology and erosion model

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rangelands are the most dominant land cover type in the United States (770 million acres) with approximately 53% of the nation’s rangelands owned and managed by the private sector, while approximately 43% are managed by the federal government. Information on the type, extent, and spatial location of...

  9. Estimating Sediment Yield on Disturbed Rangeland Using the Rangeland Hydrology and Erosion Model (RHEM)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Rangeland Hydrology and Erosion Model (RHEM) is an event-based model that estimates runoff, erosion, and sediment delivery rates and volumes at the spatial scale of the hillslope and the temporal scale of a single rainfall event. It represents erosion processes on normal rangeland, as well as, r...

  10. Using rangeland health assessment to inform successional management

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rangeland health assessment provides qualitative information on ecosystem attributes. Successional management is a conceptual framework that allows managers to link information gathered in rangeland health assessment to ecological processes that need to be repaired to allow vegetation to change in ...

  11. Weather and climate applications for rangeland restoration planning

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rangeland ecosystems generally have an arid or semi-arid climatology, and are characterized by relatively high variability in seasonal and annual patterns of precipitation. Weather variability during seedling establishment is universally acknowledged as a principal determinant of rangeland seeding...

  12. LANDSCAPE NUTRITIONAL PATTERNS AND CATTLE DISTRIBUTION IN RANGELAND PASTURES

    Technology Transfer Automated Retrieval System (TEKTRAN)

    On rangelands, uneven or unmanaged livestock distribution can adversely affect plant community composition, riparian function, or displace wildlife. These issues have historic precedents and are still a challenge for those managing rangelands. A thorough understanding of the mechanisms governing l...

  13. Is the historical range of variation relevant to rangeland management?

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rangelands occupy about 40% of the Earth’s terrestrial surface, comprising grasslands, shrublands, and deserts (Havstad et al., 2007). Over a billion people live in rangelands, engaged primarily in pastoralism and limited crop agriculture for subsistence. Rangelands can be ideal coupled human-natura...

  14. 75 FR 8036 - Monitor-Hot Creek Rangeland Project

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-02-23

    ... Forest Service Monitor-Hot Creek Rangeland Project AGENCY: Forest Service, USDA. ACTION: Notice of intent... continued livestock grazing ] within the Monitor-Hot Creek Rangeland Project area. The analysis will... conditions within the Monitor-Hot Creek Rangeland Project area towards desired conditions. The project...

  15. 43 CFR 4180.1 - Fundamentals of rangeland health.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 43 Public Lands: Interior 2 2011-10-01 2011-10-01 false Fundamentals of rangeland health. 4180.1... Fundamentals of Rangeland Health and Standards and Guidelines for Grazing Administration § 4180.1 Fundamentals of rangeland health. Standards and guidelines developed or revised by a Bureau of Land...

  16. 43 CFR 4180.1 - Fundamentals of rangeland health.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 43 Public Lands: Interior 2 2013-10-01 2013-10-01 false Fundamentals of rangeland health. 4180.1... Fundamentals of Rangeland Health and Standards and Guidelines for Grazing Administration § 4180.1 Fundamentals of rangeland health. Standards and guidelines developed or revised by a Bureau of Land...

  17. 43 CFR 4180.1 - Fundamentals of rangeland health.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 43 Public Lands: Interior 2 2014-10-01 2014-10-01 false Fundamentals of rangeland health. 4180.1... Fundamentals of Rangeland Health and Standards and Guidelines for Grazing Administration § 4180.1 Fundamentals of rangeland health. Standards and guidelines developed or revised by a Bureau of Land...

  18. 43 CFR 4180.1 - Fundamentals of rangeland health.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 43 Public Lands: Interior 2 2012-10-01 2012-10-01 false Fundamentals of rangeland health. 4180.1... Fundamentals of Rangeland Health and Standards and Guidelines for Grazing Administration § 4180.1 Fundamentals of rangeland health. Standards and guidelines developed or revised by a Bureau of Land...

  19. Sediment source determination using fallout Cesium-137 in arid rangelands.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sediment source identification in arid rangelands is necessary to understanding rangeland conditions and developing management practices to improve rangeland health and reduce sediment load to streams. The purpose of this research was to use Cesium-137 to identify sources of sediments in an arid ran...

  20. Estimating effects of targeted conservation on nonfederal rangelands

    Technology Transfer Automated Retrieval System (TEKTRAN)

    On arid and semiarid rangelands, soil erosion is episodic in nature because of extremes in precipitation from year to year. Evaluation of long-term, average, annual soil loss on rangeland is inappropriate because, in many cases, water-induced soil erosion may not occur on arid or semiarid rangelands...

  1. A new Splash and Sheet Erosion Equation for Rangelands 1957

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Soil loss rates predicted from erosion models for rangelands have the potential to be important quantitative indicators for rangeland health and for assessing conservation practice effects. Splash and sheet erosion processes on rangelands differ in substantial ways from those in croplands, where the...

  2. SAC-B, Argentine scientific satellite

    NASA Technical Reports Server (NTRS)

    Gulich, J. M.; White, C.

    1994-01-01

    The project and the missions of the Argentine scientific satellite, SAC-B, are summarized. SAC-B is an international cooperative project between NASA and the Secretariat of State of Science and Technology of the Argentine Republic. The objective of SAC-B is to advance the study of solar physics and astrophysics through the examination of solar flares, gamma ray burst sources and the diffuse soft X-ray cosmic background. The scientific payload comprises an instrument to measure the temporal evolution of X-ray emissions from solar flares as well as nonsolar gamma ray bursts, a combined soft X-ray and gamma ray burst detector, a diffuse X-ray background detector, and an energetic neutral atoms detector.

  3. Western rangelands: overgrazed and undermanaged

    SciTech Connect

    Sheridan, D.

    1981-05-01

    Overgrazing and poor management of the western arid lands causes desertification as the levels of water tables and surface waters drop, top soil and surface waters become more saline, soil erodes, and native vegetation disappears. This process had led to severe desertification in an estimated 1.1 million square miles and very severe desertification on 10,500 square miles in the US. The three areas in the very severe category occur in the Navajo Indian reservation in Arizona and New Mexico and on either side of El Paso, Texas. All were subjected to overgrazing. Government policies have only recently tried to bring public land grazing in line with the land's carrying capacity by focusing on long-term productivity. The Public Rangelands Improvement Act of 1978 authorizes better management and multiple use of public lands, but the Bureau of Land Management has not established an effective monitoring system to ensure its implementation or to overcome political constraints against reducing livestock. Ranchers disagree with the assessments made by scientists and support vegetation modification instead of grazing allotments. 58 references, 7 figures. (DCK)

  4. Turning information into knowledge for rangeland management

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The kind of knowledge system that will be capable of meeting the needs of rangeland managers will evolve as scientists, technology specialists, managers, and biologists find ways to integrate the ever expanding array of information systems and tools to meet their needs. The tools and techniques high...

  5. UAS remote sensing missions for rangeland applications

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rangelands cover about 50% of the earth’s land surface, are in remote areas and have low population densities, all of which provide an ideal opportunity for remote sensing applications from unmanned aircraft systems (UAS). In this paper, we describe a proven workflow for UAS-based remote sensing, an...

  6. CONTROL OF RANGELAND GRASSHOPPERS USING PRESCRIBED FIRE

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Grasshoppers (Orthoptera: Acrididae) are considered among the most damaging rangeland pests yet desired for the development of many wildlife species. Most grasshoppers are innocuous, but control with insecticides is non-discriminatory among species. Our objectives were to evaluate the effects of p...

  7. Invasive Plants on Rangelands: a Global Threat

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Invasive plant species are spreading and invading rangelands at an unprecedented rate costing ranchers billions of dollars to control invasive plants each year. In its simplest form, the invasion process has four primary stages, including introduction, establishment, spread and colonization. Th...

  8. Rehabilitation of cheatgrass-infested rangelands: concepts

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The introduction and subsequent invasion of cheatgrass (Bromus tectorum) onto millions of acres of Intermountain West rangelands has caused astronomical changes to numerous ecosystems and the multiple uses that depend on healthy and functional ecosystems. This is the first part, of a 3-part series ...

  9. Improving estimates of rangeland carbon storage

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Terrestrial carbon sequestration on rangelands has the potential to make a substantial contribution to the reduction of greenhouse gas (GHG) levels in the atmosphere and mitigate the effects of global climate change. This enhanced sequestration can be accomplished through the management of soils and...

  10. Managing Complex Problems in Rangeland Ecosystems

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Management of rangelands, and natural resources in general, has become increasingly complex. There is an atmosphere of increasing expectations for conservation efforts associated with a variety of issues from water quality to endangered species. We argue that many current issues are complex by their...

  11. Is rangeland health relevant to Mongolia?

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Approximately 800,000 of Mongolia’s 2.5 million people depend directly on livestock production and rangelands for their livelihood. Overgrazing is widespread in the western provinces and near the capital city of Ulaanbaatar, while forage is often underutilized in eastern parts of the country. The ra...

  12. Adaptive management for drought on rangelands

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Adaptive management for drought on rangelands encompasses 1) enterprise flexibility – herd structure where the proportion of cow-calf pairs and yearlings provides plasticity to match forage availability with forage demand, with advantages to economic returns and increased resiliency of plant communi...

  13. National estimates of soil loss on rangelands

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Since 1995, an interagency group composed of the Natural Resources Conservation Service, Agricultural Research Service, and U.S. Geological Survey have worked together to develop a robust field approach for National Resource Inventory (NRI) on rangeland. The new NRI protocols are designed to detect ...

  14. Insecticide transfer efficiency and lethal load in Argentine ants

    NASA Astrophysics Data System (ADS)

    Hooper-Bui, L. M.; Kwok, E. S. C.; Buchholz, B. A.; Rust, M. K.; Eastmond, D. A.; Vogel, J. S.

    2015-10-01

    Trophallaxis between individual worker ants and the toxicant load in dead and live Argentine ants (Linepithema humile) in colonies exposed to fipronil and hydramethylnon experimental baits were examined using accelerator mass spectrometry (AMS). About 50% of the content of the crop containing trace levels of 14C-sucrose, 14C-hydramethylnon, and 14C-fipronil was shared between single donor and recipient ants. Dead workers and queens contained significantly more hydramethylnon (122.7 and 22.4 amol/μg ant, respectively) than did live workers and queens (96.3 and 10.4 amol/μg ant, respectively). Dead workers had significantly more fipronil (420.3 amol/μg ant) than did live workers (208.5 amol/μg ant), but dead and live queens had equal fipronil levels (59.5 and 54.3 amol/μg ant, respectively). The distribution of fipronil differed within the bodies of dead and live queens; the highest amounts of fipronil were recovered in the thorax of dead queens whereas live queens had the highest levels in the head. Resurgence of polygynous ant colonies treated with hydramethylnon baits may be explained by queen survival resulting from sublethal doses due to a slowing of trophallaxis throughout the colony. Bait strategies and dose levels for controlling insect pests need to be based on the specific toxicant properties and trophic strategies for targeting the entire colony.

  15. Insecticide Transfer Efficiency and Lethal Load in Argentine Ants

    SciTech Connect

    Hooper-Bui, L. M.; Kwok, E S.C.; Buchholz, B. A.; Rust, M. K.; Eastmond, D. A.; Vogel, J. S.

    2015-07-03

    Trophallaxis between individual worker ants and the toxicant load in dead and live Argentine ants (Linepithema humile) in colonies exposed to fipronil and hydramethylnon experimental baits were examined using accelerator mass spectrometry (AMS). About 50% of the content of the crop containing trace levels of 14C-sucrose, 14C-hydramethylnon, and 14C-fipronil was shared between single donor and recipient ants. Dead workers and queens contained significantly more hydramethylnon (122.7 and 22.4 amol/μg ant, respectively) than did live workers and queens (96.3 and 10.4 amol/μg ant, respectively). Dead workers had significantly more fipronil (420.3 amol/μg ant) than did live workers (208.5 amol/μg ant), but dead and live queens had equal fipronil levels (59.5 and 54.3 amol/μg ant, respectively). Moreover, the distribution of fipronil differed within the bodies of dead and live queens; the highest amounts of fipronil were recovered in the thorax of dead queens whereas live queens had the highest levels in the head. Resurgence of polygynous ant colonies treated with hydramethylnon baits may be explained by queen survival resulting from sublethal doses due to a slowing of trophallaxis throughout the colony. The bait strategies and dose levels for controlling insect pests need to be based on the specific toxicant properties and trophic strategies for targeting the entire colony.

  16. Insecticide Transfer Efficiency and Lethal Load in Argentine Ants

    DOE PAGESBeta

    Hooper-Bui, L. M.; Kwok, E S.C.; Buchholz, B. A.; Rust, M. K.; Eastmond, D. A.; Vogel, J. S.

    2015-07-03

    Trophallaxis between individual worker ants and the toxicant load in dead and live Argentine ants (Linepithema humile) in colonies exposed to fipronil and hydramethylnon experimental baits were examined using accelerator mass spectrometry (AMS). About 50% of the content of the crop containing trace levels of 14C-sucrose, 14C-hydramethylnon, and 14C-fipronil was shared between single donor and recipient ants. Dead workers and queens contained significantly more hydramethylnon (122.7 and 22.4 amol/μg ant, respectively) than did live workers and queens (96.3 and 10.4 amol/μg ant, respectively). Dead workers had significantly more fipronil (420.3 amol/μg ant) than did live workers (208.5 amol/μg ant), butmore » dead and live queens had equal fipronil levels (59.5 and 54.3 amol/μg ant, respectively). Moreover, the distribution of fipronil differed within the bodies of dead and live queens; the highest amounts of fipronil were recovered in the thorax of dead queens whereas live queens had the highest levels in the head. Resurgence of polygynous ant colonies treated with hydramethylnon baits may be explained by queen survival resulting from sublethal doses due to a slowing of trophallaxis throughout the colony. The bait strategies and dose levels for controlling insect pests need to be based on the specific toxicant properties and trophic strategies for targeting the entire colony.« less

  17. Cross-protection in nonhuman primates against Argentine hemorrhagic fever.

    PubMed Central

    Weissenbacher, M C; Coto, C E; Calello, M A; Rondinone, S N; Damonte, E B; Frigerio, M J

    1982-01-01

    The susceptibility of the marmoset Callithrix jacchus to Tacaribe virus infection was investigated to perform cross-protection studies between Junin and Tacaribe viruses. Five marmosets inoculated with Tacaribe virus failed to show any signs of disease, any alterations in erythrocyte, leukocyte, reticulocyte, and platelet counts or any changes in hematocrit or hemoglobin values. No Tacaribe virus could be recovered from blood at any time postinfection. Anti-Tacaribe neutralizing antibodies appeared 3 weeks postinfection. The five Tacaribe-infected marmosets and four noninfected controls were challenged with the pathogenic strain of Junin virus on day 60 post-Tacaribe infection. The former group showed no signs of disease, no viremia, and no challenge virus replication, whereas the control group exhibited the typical symptoms of Argentine hemorrhagic fever, high viremia, and viral titers in organs. Soon after challenge, the Tacaribe-protected marmosets synthesized neutralizing antibodies against Junin virus. These results indicate that the marmoset C. jacchus can be considered an experimental model for protection studies with arenaviruses and that the Tacaribe virus could be considered as a potential vaccine against Junin virus. PMID:6276301

  18. REVEGETATION SUCCESS OF MEDUSAHEAD-INFESTED RANGELANDS WITH PLATEAU® AND PRESCRIBED BURNING

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Medusahead (Taeniatherum caput-medusae (L.) Nevski) is an invasive annual grass that is rapidly invading rangelands. Medusahead invasion reduces the productivity and biodiversity of rangelands. Efforts to control medusahead and revegetation infested rangelands are often unsuccessful. We evaluated...

  19. Sediment Budgets and Source Determination Using Fallout Cesium-137 in Semiarid Rangelands

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Analysis of soil redistribution and sediment sources in semiarid and arid rangelands can provide information for understanding watershed sediment budgets and rangeland conditions and for implementing management practices to improve rangeland conditions and reduce sediment loads in streams. The purpo...

  20. Rangeland Rummy - a board game to support adaptive management of rangeland-based livestock systems.

    PubMed

    Farrié, B; Jouven, M; Launay, F; Moreau, J-C; Moulin, C-H; Piquet, M; Taverne, M; Tchakérian, E; Thénard, V; Martin, G

    2015-01-01

    Rangeland-based livestock systems have to deal with the significant instability and uncertainty of the agricultural context (policy changes, volatility of input prices, etc.), and especially of the climatic context. Thus, they are particularly concerned by adaptive management strategies. To support the development of such strategies, we developed a board game including a computer model called "Rangeland Rummy". It is to be used by groups of farmers and agricultural consultants in the context of short workshops (about 3 h). Rangeland Rummy builds upon five types of material object: (i) a game board; (ii) a calendar stick indicating the starting date of the game board; (iii) sticks marked with the feed resources available for combinations of vegetation types and their management practices; (iv) cards to define animal groups and their feeding requirements throughout the year; (v) cards related to types of feed that can be attributed to animal groups throughout the year. Using these material objects, farmers collectively design a rangeland-based livestock system. This system is immediately evaluated using a computer model, i.e. a spreadsheet providing graphs and indicators providing information on, among other things, the extent to which quantitative and qualitative animal feeding requirements are covered across the year. Playing the game thus consists in collectively and iteratively designing and evaluating rangeland-based livestock systems, while confronting the players with new contextual challenges (e.g. interannual variability of weather, volatility of input prices) or new farmers' objectives (e.g. being self-sufficient for animal feeding). An example of application of Rangeland Rummy with 3 farmers in southern France is reported. Applications show that it tends to develop farmers' adaptive capacity by stimulating their discussions and the exchange of locally-relevant knowledge on management strategies and practices in rangeland-based livestock systems. PMID

  1. A qualitative evaluation of Landsat imagery of Australian rangelands

    USGS Publications Warehouse

    Graetz, R.D.; Carneggie, David M.; Hacker, R.; Lendon, C.; Wilcox, D.G.

    1976-01-01

    The capability of multidate, multispectral ERTS-1 imagery of three different rangeland areas within Australia was evaluated for its usefulness in preparing inventories of rangeland types, assessing on a broad scale range condition within these rangeland types, and assessing the response of rangelands to rainfall events over large areas. For the three divergent rangeland test areas, centered on Broken W, Alice Springs and Kalgoorlie, detailed interpretation of the imagery only partially satisfied the information requirements set. It was most useful in the Broken Hill area where fenceline contrasts in range condition were readily visible. At this and the other sites an overstorey of trees made interpretation difficult. Whilst the low resolution characteristics and the lack of stereoscopic coverage hindered interpretation it was felt that this type of imagery with its vast coverage, present low cost and potential for repeated sampling is a useful addition to conventional aerial photography for all rangeland types.

  2. Modeling Overland Erosion on Disturbed Rangeland

    NASA Astrophysics Data System (ADS)

    Al-Hamdan, O. Z.; Hernandez, M.; Pierson, F. B.; Nearing, M.; Stone, J. J.; Williams, C. J.; Boll, J.; Weltz, M.

    2012-12-01

    The Rangeland Hydrology and Erosion Model (RHEM) is a new process-based model developed by the USDA-ARS primarily for undisturbed rangeland. Greater sediment detachment rates are usually generated by concentrated flow rather than by sheet flow. Disturbance on rangeland such as fire and tree encroachment can increase overland flow erosion rate by increasing the likelihood of concentrated flow formation on a more erodible surface. In this study, we made advancement to RHEM by developing a new version of the model to predict concentrated flow erosion rate from disturbed rangelands. The model was conceptualized based on observations and results of experimental studies on rangelands disturbed by fire and/or by tree encroachment. A logistic equation was used to partition overland flow into concentrated flow and sheet flow. The equation predicts the probability of overland flow to become concentrated based on slope angle, percentage bare soil, and flow discharge per unit width. Sediment detachment rate from concentrated flow was calculated using soil erodibility of the site and hydraulic parameters of the flow such as flow width and stream power. Soil detachment was assumed to start when concentrated flow starts (i.e. no threshold concept for initiating detachment was used). Width of concentrated flow was determined by flow discharge and slope using an equation which was developed specifically for rangeland. A dynamic erodibility concept was used where concentrated flow erodibility was set to be high at the beginning of the event and then decrease exponentially due to the reduction of availability of disturbance-source-sediment. Initial erodibility was estimated using an empirical parameterization equation as a function of readily available vegetation cover and surface soil texture data. Detachment rate from rain splash and sheet flow was determined by rainfall intensity and sheet flow discharge. A dynamic partial differential sediment continuity equation was used to

  3. Integration of Hyperspectral Data for Rangeland Characterization

    SciTech Connect

    Petrie, Gregg M.; Cullinan, Valerie I.; Cadwell, Larry L.; Downs, Janelle L.; Perry, Eileen M.; Turner, Jim

    2000-12-30

    Grazing lands in the United States consist of approximately 312 million hectares of federal, state, and private land. A recent review by the National Research Council indicates a need to collect comprehensive, consistent, and uniform data to evaluate rangeland health. The Pacific Northwest National Laboratory (PNNL) is assisting the U.S. Bureau of Land Management, and working cooperatively with the U.S. Forest Service, and the U.S. Natural Resource Conservation Service to address these data needs using new remote sensing methods designed to characterize large areas quickly and at minimal cost. Anticipated application for new remote sensing protocols range from conducting national assessments of the ecological condition of rangelands to monitoring change in condition of individual grazing allotments.

  4. Where and how Argentine ant (Linepithema humile) spreads in Corsica?

    PubMed

    Blight, Olivier; Orgeas, Jérôme; Renucci, Marielle; Tirard, Alain; Provost, Erick

    2009-08-01

    The Argentine ant, Linepithema humile (Dolichoderinae), is one of the most widespread invasive ant species in the world. When established in optimal habitat, this species usually excludes most other local ants and can heavily impact other arthropods as well. Although Argentine ants have been present in southern Europe for more than 100 years, they were first noted in Corsica, a French Mediterranean island, in 1957 in only one urban station. In this study, we aimed to map precisely their geographical distribution in Corsica and to quantify their presence by using an infestation index. We recorded changes in the distribution of Argentine ants in Corsica over the past decade. Argentine ants appeared to be well established within their introduced range and spreading along the Corsican coasts principally through Human-mediated jump-dispersal but not homogenously. PMID:19632658

  5. Pheromone disruption of Argentine ant trail integrity

    USGS Publications Warehouse

    Suckling, D.M.; Peck, R.W.; Manning, L.M.; Stringer, L.D.; Cappadonna, J.; El-Sayed, A. M.

    2008-01-01

    Disruption of Argentine ant trail following and reduced ability to forage (measured by bait location success) was achieved after presentation of an oversupply of trail pheromone, (Z)-9-hexadecenal. Experiments tested single pheromone point sources and dispersion of a formulation in small field plots. Ant walking behavior was recorded and digitized by using video tracking, before and after presentation of trail pheromone. Ants showed changes in three parameters within seconds of treatment: (1) Ants on trails normally showed a unimodal frequency distribution of walking track angles, but this pattern disappeared after presentation of the trail pheromone; (2) ants showed initial high trail integrity on a range of untreated substrates from painted walls to wooden or concrete floors, but this was significantly reduced following presentation of a point source of pheromone; (3) the number of ants in the pheromone-treated area increased over time, as recruitment apparently exceeded departures. To test trail disruption in small outdoor plots, the trail pheromone was formulated with carnuba wax-coated quartz laboratory sand (1 g quartz sand/0.2 g wax/1 mg pheromone). The pheromone formulation, with a half-life of 30 h, was applied by rotary spreader at four rates (0, 2.5, 7.5, and 25 mg pheromone/m2) to 1- and 4-m2 plots in Volcanoes National Park, Hawaii. Ant counts at bait cards in treated plots were significantly reduced compared to controls on the day of treatment, and there was a significant reduction in ant foraging for 2 days. These results show that trail pheromone disruption of Argentine ants is possible, but a much more durable formulation is needed before nest-level impacts can be expected. ?? 2008 Springer Science+Business Media, LLC.

  6. Pheromone disruption of Argentine ant trail integrity.

    PubMed

    Suckling, D M; Peck, R W; Manning, L M; Stringer, L D; Cappadonna, J; El-Sayed, A M

    2008-12-01

    Disruption of Argentine ant trail following and reduced ability to forage (measured by bait location success) was achieved after presentation of an oversupply of trail pheromone, (Z)-9-hexadecenal. Experiments tested single pheromone point sources and dispersion of a formulation in small field plots. Ant walking behavior was recorded and digitized by using video tracking, before and after presentation of trail pheromone. Ants showed changes in three parameters within seconds of treatment: (1) Ants on trails normally showed a unimodal frequency distribution of walking track angles, but this pattern disappeared after presentation of the trail pheromone; (2) ants showed initial high trail integrity on a range of untreated substrates from painted walls to wooden or concrete floors, but this was significantly reduced following presentation of a point source of pheromone; (3) the number of ants in the pheromone-treated area increased over time, as recruitment apparently exceeded departures. To test trail disruption in small outdoor plots, the trail pheromone was formulated with carnuba wax-coated quartz laboratory sand (1 g quartz sand/0.2 g wax/1 mg pheromone). The pheromone formulation, with a half-life of 30 h, was applied by rotary spreader at four rates (0, 2.5, 7.5, and 25 mg pheromone/m(2)) to 1- and 4-m(2) plots in Volcanoes National Park, Hawaii. Ant counts at bait cards in treated plots were significantly reduced compared to controls on the day of treatment, and there was a significant reduction in ant foraging for 2 days. These results show that trail pheromone disruption of Argentine ants is possible, but a much more durable formulation is needed before nest-level impacts can be expected. PMID:19034574

  7. Strategies for sustaining multiple ecosystem services from rangelands

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The application of natural resource science to both management needs and policy formation has been spotty, at best. Interestingly, rangeland science had an early history of closely supporting management needs and USA rangeland policies during the early 20th century. This history of support unrave...

  8. Making spatial predictions of rangeland ecosystem attributes using regression kriging

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sound rangeland management requires accurate information on condition over large landscapes. Typical approaches to making spatial predictions rangeland condition attributes (e.g., shrub or bare ground cover) are via regression between field and remotely-sensed data. This works well in some situation...

  9. Contributing to the mitigation of climate change using rangeland management

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The mitigation of climate change through rangeland management based projects seems to be viable in the marketplace. Carbon sequestration via rangeland management has a sound basis in both economics and ecology if the offset projects are compatible with existing land uses and management systems. Ho...

  10. Grand challenges for resilience-based management of rangelands

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The social and ecological contexts for rangeland management are changing rapidly, prompting a reevaluation of science, management, and the linkages between them. Here, we argue that the recent transformation from a steady state to an ecosystem management model has served the rangeland profession wel...

  11. Conservation program participation and adaptive rangeland decision-making

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This paper analyzes rancher participation in conservation programs in the context of a social-ecological framework for adaptive rangeland management. We argue that conservation programs are best understood as one of many strategies of adaptively managing rangelands in ways that sustain livelihoods a...

  12. Mongolia's rangelands: is livestock production the key to the future?

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Approximately half of the world’s land areas is rangeland. Over 1.5 billion people live on or immediately adjacent to this land type. Common to these rangelands are over 1 billion domesticated animals, primarily cattle, sheep and goats that are managed by pastoralists. The ruminant digestive system...

  13. Sustaining working rangelands: Insights from rancher decision making

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Grazed rangeland ecosystems encompass diverse global land resources, and are complex social-ecological systems from which society demands both goods (e.g., livestock and forage production) and services (e.g., abundant and high quality water). In the dialogue on rangeland conservation and sustainable...

  14. Developing an operational rangeland water requirement satisfaction index

    USGS Publications Warehouse

    Senay, G.B.; Verdin, J.P.; Rowland, J.

    2011-01-01

    Developing an operational water requirement satisfaction index (WRSI) for range-land monitoring is an important goal of the famine early warning systems network. An operational WRSI has been developed for crop monitoring, but until recently a comparable WRSI for rangeland was not successful because of the extremely poor performance of the index when based on published crop coefficients (Kc) for rangelands. To improve the rangeland WRSI, we developed a simple calibration technique that adjusts the Kc values for rangeland monitoring using long-term rainfall distribution and reference evapotranspiration data. The premise for adjusting the Kc values is based on the assumption that a viable rangeland should exhibit above-average WRSI (values >80%) during a normal year. The normal year was represented by a median dekadal rainfall distribution (satellite rainfall estimate from 1996 to 2006). Similarly, a long-term average for potential evapotranspiration was used as input to the famine early warning systems network WRSI model in combination with soil-water-holding capacity data. A dekadal rangeland WRSI has been operational for east and west Africa since 2005. User feedback has been encouraging, especially with regard to the end-of-season WRSI anomaly products that compare the index's performance to 'normal' years. Currently, rangeland WRSI products are generated on a dekadal basis and posted for free distribution on the US Geological Survey early warning website at http://earlywarning.usgs.gov/adds/.

  15. Management implications of global change for Great Plains rangelands

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Just as water and temperature drive the ecology of Great Plains rangelands, we predict that the impacts of global change on this region will be experienced largely through changes in these two important environmental variables. A third global change factor which will impact rangelands is increasing ...

  16. The western United States rangelands, a major resource

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rangeland is a type of land found predominantly in arid and semiarid regions, and managed as a natural ecosystem supporting vegetation of grasses, grass-like plants, forbs, or shrubs. There are approximately 761 m ac of rangeland in the United States, about 31% of the total land area. This land ty...

  17. Weather variability and adaptive management for rangeland restoration

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Inherent weather variability in upland rangeland systems requires relatively long-term goal setting, and contingency planning for partial success or failure in any given year. Rangeland plant communities are dynamic systems and successional planning is essential for achieving and maintaining system...

  18. Climate change and rangelands: Responding rationally to uncertainty

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rangelands constitute a substantial portion of the earth’s surface and contribute a wide variety of products and services to human well being. Global climate change will have an inordinate impact on rangelands because the productivity of grass and shrub dominated ecosystems is so closely linked to ...

  19. DIGITAL IMAGERY AND LANDSCAPE-SCALE RANGELAND MONITORING.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Monitoring is critical when manipulating rangeland ecosystems toward a desired goal. Unfortunately, cost and(or) logistics may limit a rangeland manager’s choice of monitoring tools. Ultimately, such tools must be affordable and provide rapid, accurate, and precise information that can be used to ...

  20. Variation in ecological resilience: a fundamental concept for rangeland ecology

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The concepts and terminology associated with ecological resilience are fast becoming a common language for the study of global change. We review the application of the broad concept of resilience to rangeland ecology, connecting it to several well-established rangeland concepts including equilibrial...

  1. New research themes after a century of rangeland science

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The rangeland science profession in the United States has its roots in the widespread overgrazing and concurrent severe droughts of the late 19th Century. These drivers contributed to rangeland resource degradation especially in the American Southwest. Experimental stations like those established ea...

  2. Spatial redistribution of nitrogen by cattle in semiarid rangeland

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Nitrogen (N) availability can strongly influence forage quality and the capacity for semiarid rangelands to respond to increasing atmospheric CO2. Although many pathways of nitrogen input and loss from rangelands have been carefully quantified, cattle-mediated N losses are often poorly understood. W...

  3. APPLICATIONS AND RESEARCH USING REMOTE SENSING FOR RANGELAND MANAGEMENT

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rangelands are grasslands, shrublands and savannas which may be used for grazing livestock in order to produce food and fiber. Assessment and monitoring of rangelands are currently based on comparing the species present in relation to a defined successional end-state. However, future assessment an...

  4. Sustainable rangeland management, economic growth, and a cautious role for the SRM

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Interest in the art and science of rangeland management increased dramatically during the 20th century and it was out of this interest that the profession of rangeland management was born. As public interest in rangeland management grew, so did the number, breadth, and depth of rangeland management ...

  5. Grazing behavioral responses of beef cattle to medusahead invasion in sagebrush steppe rangelands

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The objectives of this study are to determine: 1) seasonal forage quality of medusahead-invaded rangeland relative to adjacent rangeland supporting desirable vegetation; 2) relative grazing preference of beef cattle for medusahead-invaded rangeland and adjacent rangeland supporting desirable vegetat...

  6. Sound management may sequester methane in grazed rangeland ecosystems.

    PubMed

    Wang, Chengjie; Han, Guodong; Wang, Shiping; Zhai, Xiajie; Brown, Joel; Havstad, Kris M; Ma, Xiuzhi; Wilkes, Andreas; Zhao, Mengli; Tang, Shiming; Zhou, Pei; Jiang, Yuanyuan; Lu, Tingting; Wang, Zhongwu; Li, Zhiguo

    2014-01-01

    Considering their contribution to global warming, the sources and sinks of methane (CH4) should be accounted when undertaking a greenhouse gas inventory for grazed rangeland ecosystems. The aim of this study was to evaluate the mitigation potential of current ecological management programs implemented in the main rangeland regions of China. The influences of rangeland improvement, utilization and livestock production on CH4 flux/emission were assessed to estimate CH4 reduction potential. Results indicate that the grazed rangeland ecosystem is currently a net source of atmospheric CH4. However, there is potential to convert the ecosystem to a net sink by improving management practices. Previous assessments of capacity for CH4 uptake in grazed rangeland ecosystems have not considered improved livestock management practices and thus underestimated potential for CH4 uptake. Optimal fertilization, rest and light grazing, and intensification of livestock management contribute mitigation potential significantly. PMID:24658176

  7. Sound management may sequester methane in grazed rangeland ecosystems

    PubMed Central

    Wang, Chengjie; Han, Guodong; Wang, Shiping; Zhai, Xiajie; Brown, Joel; Havstad, Kris M.; Ma, Xiuzhi; Wilkes, Andreas; Zhao, Mengli; Tang, Shiming; Zhou, Pei; Jiang, Yuanyuan; Lu, Tingting; Wang, Zhongwu; Li, Zhiguo

    2014-01-01

    Considering their contribution to global warming, the sources and sinks of methane (CH4) should be accounted when undertaking a greenhouse gas inventory for grazed rangeland ecosystems. The aim of this study was to evaluate the mitigation potential of current ecological management programs implemented in the main rangeland regions of China. The influences of rangeland improvement, utilization and livestock production on CH4 flux/emission were assessed to estimate CH4 reduction potential. Results indicate that the grazed rangeland ecosystem is currently a net source of atmospheric CH4. However, there is potential to convert the ecosystem to a net sink by improving management practices. Previous assessments of capacity for CH4 uptake in grazed rangeland ecosystems have not considered improved livestock management practices and thus underestimated potential for CH4 uptake. Optimal fertilization, rest and light grazing, and intensification of livestock management contribute mitigation potential significantly. PMID:24658176

  8. Assessing transportation infrastructure impacts on rangelands: Test of a standard rangeland assessment protocol

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Linear disturbances associated with on and off-road vehicle use on rangelands has increased dramatically throughout the world in recent decades. This increase is due to a variety of factors including increased availability of all-terrain vehicles, infrastructure development (oil, gas, renewable ene...

  9. Rangeland Hydrology and Erosion Model (RHEM) enhancements for applications on disturbed rangelands

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Rangeland Hydrology and Erosion Model (RHEM) is a new process-based model developed by the USDA-ARS. Disturbance such as fire or woody plant encroachment can amplify overland flow erosion by increasing the likelihood of concentrated flow formation. In this study, we enhanced RHEM applications on...

  10. Modeling soil erosion impact of rangeland disturbance using the Rangeland Hydrology and Erosion Model (RHEM)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Disturbance on rangeland such as fire and tree encroachment can increase overland flow erosion rate by increasing the likelihood of concentrated flow formation on a more erodible surface. In this study, we made advancements to RHEM by developing a new version of the model to predict concentrated flo...

  11. Rangeland health assessment - The key to understanding and assessing rangeland soil health in the Northern Great Plains

    Technology Transfer Automated Retrieval System (TEKTRAN)

    As the science related to soil and rangeland health evolves, so do their protocols and assessment methodologies. Rangeland health assessments consist of evaluating how well ecological processes such as the water cycle, energy flow and nutrient cycling are functioning at a site. Soil health is the ca...

  12. Maintaining ecosystem services through continued livestock production on California rangelands

    NASA Astrophysics Data System (ADS)

    Barry, S.; Becchetti, T.

    2015-12-01

    Nearly 40% of California is rangeland comprising the largest land type in California and providing forage for livestock, primarily beef cattle. In addition to forage, rangelands provide a host of ecosystem systems services, including habitat for common and endangered species, fire fuels management, pollination services, clean water, viewsheds, and carbon sequestration. Published research has documented that most of these ecosystem services are positively impacted by managed livestock grazing and rancher stewardship. Ranchers typically do not receive any monetary reimbursement for their stewardship in providing these ecosystem services to the public. Markets have been difficult to establish with limited ability to adequately monitor and measure services provided. At the same time, rangelands have been experiencing rapid conversion to urbanization and more profitable and intensive forms of agriculture such as almond and walnut orchards. To prevent further conversion of rangelands and the loss of the services they provide, there needs to be a mechanism to identify and compensate landowners for the value of all products and services being received from rangelands. This paper considers two methods (opportunity cost and avoided cost) to determine the value of Payment for Ecosystem Services (PES) for rangelands. PES can raise the value of rangelands, making them more competitive financially. Real estate values and University of California Cooperative Extension Cost Studies, were used to demonstrate the difference in value (lost opportunity cost) between the primary products of rangelands (livestock production) and the products of the converted rangelands (almond and walnut orchards). Avoided costs for vegetation management and habitat creation and maintenance were used to establish the value of managed grazing. If conversion is to be slowed or stopped and managed grazing promoted to protect the ecosystem services rangelands provide, this value could be compensated through

  13. Biophysical characterization and management effects on semiarid rangeland observed from Landsat ETM+ data

    SciTech Connect

    Fang, Hongliang; Liang, Shunlin; McClaran, Mitchell P.; van Leeuwen, Willem J. D.; Drake, Sam; Marsh, Stuart E.; Thomson, Allison M.; Izaurralde, R Cesar C.; Rosenberg, Norman J.

    2005-01-20

    Semi-arid rangelands are very sensitive to global climatic change; studies of their biophysical attributes are crucial to understanding the dynamics of rangeland ecosystems under human disturbance. In the Santa Rita Experimental Range (SRER), Arizona, the vegetation has changed considerably and there have been many management activities applied. This study calculates seven surface variables: the enhanced vegetation index (EVI), the normalized difference vegetation index (NDVI), surface albedos (total shortwave, visible and near-infrared), leaf area index (LAI) and the fraction of photosynthetically active radiation absorbed by green vegetation (FPAR) from the Enhanced Thematic Mapper (ETM+) data. Comparison with the MODIS (Moderate Resolution Imaging Spectroradiometer) vegetation index and albedo products indicate they agree well with our estimates from ETM+ while their LAI and FPAR are larger than ETM+. Human disturbance has significantly changed the cover types and biophysical conditions. Statistical tests indicate that surface albedos increased and FPAR decreased at all sites. The recovery will require more than 67 years, and is about 50% complete within 40 years at the higher elevation. Grass cover, vegetation indices, albedos and LAI recovered from cutting faster at the higher elevation. Woody plants, vegetation indices and LAI have recovered to their original characteristics after 65 years at the lower elevation. More studies are needed to examine the spectral characteristics of different ground components.

  14. Carbohydrate supply limits invasion of natural communities by Argentine ants.

    PubMed

    Rowles, Alexei D; Silverman, Jules

    2009-08-01

    The ability of species to invade new habitats is often limited by various biotic and physical factors or interactions between the two. Invasive ants, frequently associated with human activities, flourish in disturbed urban and agricultural environments. However, their ability to invade and establish in natural habitats is more variable. This is particularly so for the invasive Argentine ant (Linepithema humile). While biotic resistance and low soil moisture limits their invasion of natural habitats in some instances, the effect of food availability has been poorly explored. We conducted field experiments to determine if resource availability limits the spread and persistence of Argentine ants in remnant natural forest in North Carolina. Replicated transects paired with and without sucrose solution feeding stations were run from invaded urban edges into forest remnants and compared over time using baits and direct counts at feeding stations. Repeated under different timing regimes in 2006 and 2007, access to sucrose increased local Argentine ant abundances (1.6-2.5 fold) and facilitated their progression into the forest up to 73 +/- 21% of 50-m transects. Resource removal caused an expected decrease in Argentine ant densities in 2006, in conjunction with their retreat to the urban/forest boundary. However, in 2007, Argentine ant numbers unexpectedly continued to increase in the absence of sugar stations, possibly through access to alternative resources or conditions not available the previous year such as honeydew-excreting Hemiptera. Our results showed that supplementing carbohydrate supply facilitates invasion of natural habitat by Argentine ants. This is particularly evident where Argentine ants continued to thrive following sugar station removal. PMID:19452171

  15. Rangeland degradation in North China: perceptions of pastoralists.

    PubMed

    Ho, Peter; Azadi, Hossein

    2010-04-01

    Rangeland degradation, a worldwide problem, is serious in China, especially in the Northern provinces. To assess the pastoralists' perceptions toward rangeland trend and degradation, a survey was conducted in Ningxia, North China. Data were collected from a total of 284 pastoralists in six Ningxia counties. Findings showed that the majority of respondents believe the rangelands in Ningxia have been degraded, although there are some disparities among the counties that illustrate differing severity of degradation. Findings also clarified that the pastoralists have more knowledge about the "technical" and "supportive" aspects of conditions, while remaining less aware of "economic" and "management" factors of this issue. Yet, a high disparity was revealed between pastoralists' perceptions among the counties in this study. The correlation matrix showed that most of their perceptions do not act independently. Findings also showed that those pastoralists who believe that their rangeland trend is "improved" have broader management and social perceptions than those who believe their rangeland is "degraded". Finally, correlation analysis showed that the management and social perceptions have a negative correlation with degradation severity. Based on the findings, recommendations for possible interventions through extension/educational programs to diminish rangeland degradation are made. The programs are suggested to be presented in three packages including "management", "social", and "economic" issues in rangeland degradation. PMID:20106474

  16. Detrimental effects of highly efficient interference competition: invasive Argentine ants outcompete native ants at toxic baits.

    PubMed

    Buczkowski, Grzegorz; Bennett, Gary W

    2008-06-01

    The Argentine ant (Linepithema humile) is an invasive species that disrupts the balance of natural ecosystems by displacing indigenous ant species throughout its introduced range. Previous studies that examined the mechanisms by which Argentine ants attain ecological dominance showed that superior interference and exploitation competition are key to the successful displacement of native ant species. The objective of this research was to test the hypothesis that effective interference competition by Argentine ants may also be detrimental to the survival of Argentine ant colonies where Argentine ants and native ants compete at toxic baits used to slow the spread of Argentine ants. To study this hypothesis, we examined the competitive interactions between Argentine ants and native odorous house ants, Tapinoma sessile, in the presence and absence of toxic baits. Results showed that Argentine ants aggressively outcompete T. sessile from toxic baits through efficient interference competition and monopolize bait resources. This has severe negative consequences for the survival of Argentine ants as colonies succumb to the toxic effects of the bait. In turn, T. sessile avoid areas occupied by Argentine ants, give up baits, and consequently suffer minimal mortality. Our results provide experimental evidence that highly efficient interference competition may have negative consequences for Argentine ants in areas where toxic baits are used and may provide a basis for designing innovative management programs for Argentine ants. Such programs would have the double benefit of selectively eliminating the invasive species while simultaneously protecting native ants from the toxic effects of baits. PMID:18559180

  17. Sediment retention in rangeland riparian buffers.

    PubMed

    Hook, Paul B

    2003-01-01

    Controlling nonpoint-source sediment pollution is a common goal of riparian management, but there is little quantitative information about factors affecting performance of rangeland riparian buffers. This study evaluated the influence of vegetation characteristics, buffer width, slope, and stubble height on sediment retention in a Montana foothills meadow. Three vegetation types (sedge wetland, rush transition, bunchgrass upland) were compared using twenty-six 6- x 2-m plots spanning 2 to 20% slopes. Plots were clipped moderately (10-15 cm stubble) or severely (2-5 cm stubble). Sediment (silt + fine sand) was added to simulated overland runoff 6, 2, or 1 m above the bottom of each plot. Runoff was sampled at 15-s to > 5-min intervals until sediment concentrations approached background levels. Sediment retention was affected strongly by buffer width and moderately by vegetation type and slope, but was not affected by stubble height. Mean sediment retention ranged from 63 to > 99% for different combinations of buffer width and vegetation type, with 94 to 99% retention in 6-m-wide buffers regardless of vegetation type or slope. Results suggest that rangeland riparian buffers should be at least 6 m wide, with dense vegetation, to be effective and reliable. Narrower widths, steep slopes, and sparse vegetation increase risk of sediment delivery to streams. Vegetation characteristics such as biomass, cover, or density are more appropriate than stubble height for judging capacity to remove sediment from overland runoff, though stubble height may indirectly indicate livestock impacts that can affect buffer performance. PMID:12809315

  18. Recovering lead from batteries

    NASA Astrophysics Data System (ADS)

    David Prengaman, R.

    1995-01-01

    Over the past 20 years, a significant number of processes have been developed to recover lead from scrap batteries. These processes recover lead via hydrometallurgical processing of the paste component of the battery followed by electrowinning. A number of pilot plant operations have been conducted, but thus far none of the processes have become operational.

  19. Assessing transportation infrastructure impacts on rangelands: test of a standard rangeland assessment protocol

    USGS Publications Warehouse

    Duniway, Michael C.; Herrick, Jeffrey E.; Pyke, David A.; Toledo, David

    2010-01-01

    Linear disturbances associated with on- and off-road vehicle use on rangelands has increased dramatically throughout the world in recent decades. This increase is due to a variety of factors including increased availability of all-terrain vehicles, infrastructure development (oil, gas, renewable energy, and ex-urban), and recreational activities. In addition to the direct impacts of road development, the presence and use of roads may alter resilience of adjoining areas through indirect effects such as altered site hydrologic and eolian processes, invasive seed dispersal, and sediment transport. There are few standardized methods for assessing impacts of transportation-related land-use activities on soils and vegetation in arid and semi-arid rangelands. Interpreting Indicators of Rangeland Health (IIRH) is an internationally accepted qualitative assessment that is applied widely to rangelands. We tested the sensitivity of IIRH to impacts of roads, trails, and pipelines on adjacent lands by surveying plots at three distances from these linear disturbances. We performed tests at 16 randomly selected sites in each of three ecosystems (Northern High Plains, Colorado Plateau, and Chihuahuan Desert) for a total of 208 evaluation plots. We also evaluated the repeatability of IIRH when applied to road-related disturbance gradients. Finally, we tested extent of correlations between IIRH plot attribute departure classes and trends in a suite of quantitative indicators. Results indicated that the IIRH technique is sensitive to direct and indirect impacts of transportation activities with greater departure from reference condition near disturbances than far from disturbances. Trends in degradation of ecological processes detected with qualitative assessments were highly correlated with quantitative data. Qualitative and quantitative assessments employed in this study can be used to assess impacts of transportation features at the plot scale. Through integration with remote

  20. [The Argentine Health System: organization and financial features].

    PubMed

    Arce, Hugo E

    2012-01-01

    The Argentine health system is defined by the following features: a) federal country organization; b) coexistence of public and private services with either outpatients or inpatients; c) fragmented entities of social security, most of these originated outside of the state organization. Components of the system are described and weighed; making decisions strength between national and provincial health authorities is analyzed and the Argentine system is compared with that of other countries. Statistical data on distribution of health expenditures and coverage of health services are presented as well as financial flow among diverse funding sources, insurers, providers and users of each sector. PMID:23089118

  1. Rotational grazing on rangelands: Reconciliation of perception and experimental evidence

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The experimental evaluation of grazing systems represents a highly visible and lengthy chapter in the history of the rangeland profession. Although experimentation has largely concluded, contrasting interpretations still remain regarding the potential benefits of rotational grazing systems on rangel...

  2. IMAGING SPECTROSCOPY FOR DETERMINING RANGELAND STRESSORS TO WESTERN WATERSHEDS

    EPA Science Inventory

    The Environmental Protection Agency is developing rangeland ecological indicators in eleven western states using advanced remote sensing systems. Fine spectral resolution (hyperspemal) sensors, or imaging spectrometers, can detect the subtle spectral features that makes vegetatio...

  3. Medusahead in sagebrush steppe rangelands: Prevention, control, and revegetation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Medusahead is an exotic annual grass invading western rangelands. Medusahead invasion is particularly troublesome, because revegetation of invaded areas is difficult. This manuscript synthesizes the literature to provide recommendations for managing medusahead in sagebrush plant communities. Beca...

  4. IMAGING SPECTROSCOPY FOR DETERMINING RANGELAND STRESSORS TO WESTERN WATERSHEDS

    EPA Science Inventory

    The Environmental Protection Agency is developing rangeland ecological indicators in twelve western states using advanced remote sensing techniques. Fine spectral resolution (hyperspectral) sensors, or imaging spectrometers, can detect the subtle spectral features that make veget...

  5. Future scenarios of impacts to ecosystem services on California rangelands

    USGS Publications Warehouse

    Byrd, Kristin; Alvarez, Pelayo; Flint, Lorraine; Flint, Alan

    2014-01-01

    The 18 million acres of rangelands in the Central Valley of California provide multiple benefits or “ecosystem services” to people—including wildlife habitat, water supply, open space, recreation, and cultural resources. Most of this land is privately owned and managed for livestock production. These rangelands are vulnerable to land-use conversion and climate change. To help resource managers assess the impacts of land-use change and climate change, U.S. Geological Survey scientists and their cooperators developed scenarios to quantify and map changes to three main rangeland ecosystem services—wildlife habitat, water supply, and carbon sequestration. Project results will help prioritize strategies to conserve these rangelands and the ecosystem services that they provide.

  6. The Mindful Attention Awareness Scale (MAAS) in an Argentine Population

    ERIC Educational Resources Information Center

    Montes, Silvana Andrea; Ledesma, Rubén Daniel; García, Natalia Mariana; Poó, Fernando Martín

    2014-01-01

    The purpose of this study was to provide evidence of validity for the Mindful Attention Awareness Scale scores in an Argentine sample (Spanish-language version). Results indicated satisfactory psychometric properties (a one-factor structure, good item discrimination, high reliability, and significant correlations with additional measures). This…

  7. Different Argentine Rural Extensionists' Mindsets and Their Practical Implications

    ERIC Educational Resources Information Center

    Landini, Fernando

    2015-01-01

    Purpose: This paper reflects upon the practice of Argentine rural extensionists working in the extension public system through the process of identifying different rural extensionists' types of mindsets and comparing them with transfer of technology extension approach, dialogical processes of horizontal knowledge exchange, participatory…

  8. Perceptions of ranchers about medusahead (Taeniatherum caput-medusae (L.) Nevski) management on sagebrush steppe rangelands

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Medusahead (Taeniatherum caput-medusae (L.) Nevski) is an exotic annual grass invading rangelands in the western United States. Medusahead is a serious management concern because its decreases biodiversity, reduces livestock forage production, and degrades ecological function of rangelands. Despit...

  9. Mapping total vegetation cover across western rangelands with moderate-resolution imaging spectroradiometer data

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Remotely sensed observations of rangelands provide a synoptic view of vegetation condition unavailable from other means. Multiple satellite platforms in operation today (e.g. Landsat, moderate-resolution imaging spectroradiometer [MODIS]) offer opportunities for regional monitoring of rangelands. Ho...

  10. Integrating a rangeland health assessment with successional management: A synergistic approach to EBIPM

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Qualitative Rangeland Health Assessments are extremely useful because they provide a relative indication of resource problems on rangelands. Additionally, theSuccessional Management framework identifies three primary causes of plantcommunity change, ecological processes, and factors that modify thes...

  11. Very High Resolution Panoramic Photography to Improve Conventional Rangeland Monitoring 1994

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rangeland monitoring often includes repeat photographs as a basis for documentation and although photographic equipment and electronics have been evolving rapidly, basic rangeland photo monitoring methods have changed little over time. Ground based digital photography is underutilized, especially s...

  12. An Integrated Social, Economic, and Ecologic Conceptual (ISEEC) framework for considering rangeland sustainability

    USGS Publications Warehouse

    Fox, W.E.; McCollum, D.W.; Mitchell, J.E.; Swanson, L.E.; Kreuter, U.P.; Tanaka, J.A.; Evans, G.R.; Theodore, Heintz H.; Breckenridge, R.P.; Geissler, P.H.

    2009-01-01

    Currently, there is no standard method to assess the complex systems in rangeland ecosystems. Decision makers need baselines to create a common language of current rangeland conditions and standards for continued rangeland assessment. The Sustainable Rangeland Roundtable (SRR), a group of private and public organizations and agencies, has created a forum to discuss rangeland sustainability and assessment. The SRR has worked to integrate social, economic, and ecological disciplines related to rangelands and has identified a standard set of indicators that can be used to assess rangeland sustainability. As part of this process, SRR has developed a two-tiered conceptual framework from a systems perspective to study the validity of indicators and the relationships among them. The first tier categorizes rangeland characteristics into four states. The second tier defines processes affecting these states through time and space. The framework clearly shows that the processes affect and are affected by each other. ?? 2009 Taylor & Francis Group, LLC.

  13. The Argentine ant persists through unfavorable winters via a mutualism facilitated by a native tree.

    PubMed

    Brightwell, Robert J; Silverman, Jules

    2011-10-01

    Mutualisms and facilitations can fundamentally change the relationship between an organism's realized and fundamental niche. Invasive species may prove particularly suitable models for investigating this relationship as many are dependent on finding new partners for successful establishment. We conducted field-based experiments testing whether a native tree facilitates the successful survival of the invasive Argentine ant, Linepithema humile (Mayr), through unfavorable winter conditions in the southeastern United States. We found Argentine ant nests aggregated around the native loblolly pine, Pinus taeda L., during the winter months. The bark of this tree absorbed enough radiant solar energy to reach temperatures suitable for Argentine ant foraging even when ambient temperatures should have curtailed all foraging. Conversely, foraging ceased when the trunk was shaded. The sun-warmed bark of this tree gave the Argentine ant access to a stable honeydew resource. Argentine ants were not found on or near deciduous trees even though bark temperatures were warm enough to permit Argentine ant foraging on cold winter days. Augmenting deciduous trees with sucrose water through the winter months lead to Argentine ant nests remaining at their base and Argentine ants foraging on the tree. The Argentine ant requires both foraging opportunity and a reliable winter food source to survive through unfavorable winter conditions in the southeastern United States. The loblolly pine provided both of these requirements extending the realized niche of Argentine ants beyond its fundamental niche. PMID:22251714

  14. PROCESS OF RECOVERING URANIUM

    DOEpatents

    Carter, J.M.; Larson, C.E.

    1958-10-01

    A process is presented for recovering uranium values from calutron deposits. The process consists in treating such deposits to produce an oxidlzed acidic solution containing uranium together with the following imparities: Cu, Fe, Cr, Ni, Mn, Zn. The uranium is recovered from such an impurity-bearing solution by adjusting the pH of the solution to the range 1.5 to 3.0 and then treating the solution with hydrogen peroxide. This results in the precipitation of uranium peroxide which is substantially free of the metal impurities in the solution. The peroxide precipitate is then separated from the solution, washed, and calcined to produce uranium trioxide.

  15. Spatial predictions of cover attributes of rangeland ecosystems using regression kriging and remote sensing

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sound rangeland management requires accurate information on rangeland condition over large landscapes. A commonly-applied approach to making spatial predictions of attributes related to rangeland condition (e.g., shrub or bare ground cover) from remote sensing is via regression between field and rem...

  16. Invasive rangeland plants in range and animal sciences and resources management

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Comprising about 50% of the world’s land surface, rangelands are an important ecological and economic resource. Rangeland plant communities are changing. Even though the composition of plant communities in rangeland changes continually through the process of succession, in more recent years this c...

  17. New concentrated flow hydraulics equations for physically-based rangeland hydrology and erosion models

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We examined the hydraulics of concentrated flow using unconfined field experimental data over diverse rangeland landscapes, and developed new empirical prediction models of different rangeland concentrated flow hydraulic parameters, which can be applicable across a wide span of rangeland sites, soil...

  18. Characteristics of concentrated flow hydraulics for rangeland ecosystems: implications for hydrologic modeling

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Concentrated flow is often the dominant source of water erosion following disturbance on rangeland. Because of the lack of studies that explain the hydraulics of concentrated flow on rangelands, cropland-based equations have typically been used for rangeland hydrology and erosion modeling, leading t...

  19. 78 FR 49723 - Humboldt-Toiyabe National Forests; Ely Ranger District; Ely Westside Rangeland Project

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-15

    ... Forest Service Humboldt-Toiyabe National Forests; Ely Ranger District; Ely Westside Rangeland Project... of the Ely Westside Rangeland Project began in 2006 with the original Notice of Intent published in... and conditions) on the allotments in the Ely Westside Rangeland Project area. The objection...

  20. Influence of grazing on rangeland soil carbon: State of the science

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The importance of rangeland to the soil carbon pools and cycles, as well as the drivers that influence soil carbon in rangelands is presented here with emphasis on grazing, global change and drought. Experimental results will be presented addressing soil carbon responses in rangelands to grazing x c...

  1. State-and-transition model archetypes: a global taxonomy of rangeland change

    Technology Transfer Automated Retrieval System (TEKTRAN)

    State and transition models (STMs) synthesize science-based and local knowledge to formally represent the dynamics of rangeland and other ecosystems. Mental models or concepts of ecosystem dynamics implicitly underlie all management decisions in rangelands and thus how people influence rangeland sus...

  2. AGWA: The Automated Geospatial Watershed Assessment Tool to inform rangeland management

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Do you want a relatively easy to use tool to assess rangeland soil and water conservation practices on rangeland erosion that is specifically designed to use ecological information? Effective rangeland management requires the ability to assess the potential impacts of management actions on soil ero...

  3. Rangelands: Changes to improve the quality and performance of an important SRM journal

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In 2008, an effort to improve the quality and financial performance of the journal RANGELANDS was begun. Reviews by the Society for Range Management (SRM) Board of Directors (BOD) appointed RANGELANDS Task Force (RTF) and the Advisory Council identified aspects of RANGELANDS critical to membership s...

  4. Fast and Flexible: Argentine Ants Recruit from Nearby Trails

    PubMed Central

    Flanagan, Tatiana P.; Pinter-Wollman, Noa M.; Moses, Melanie E.; Gordon, Deborah M.

    2013-01-01

    Argentine ants (Linepithema humile) live in groups of nests connected by trails to each other and to stable food sources. In a field study, we investigated whether some ants recruit directly from established, persistent trails to food sources, thus accelerating food collection. Our results indicate that Argentine ants recruit nestmates to food directly from persistent trails, and that the exponential increase in the arrival rate of ants at baits is faster than would be possible if recruited ants traveled from distant nests. Once ants find a new food source, they walk back and forth between the bait and sometimes share food by trophallaxis with nestmates on the trail. Recruiting ants from nearby persistent trails creates a dynamic circuit, like those found in other distributed systems, which facilitates a quick response to changes in available resources. PMID:23967129

  5. The Argentine ant: challenges in managing an invasive unicolonial pest.

    PubMed

    Silverman, Jules; Brightwell, Robert John

    2008-01-01

    The Argentine ant, Linepithema humile, has invaded urban, agricultural, and natural habitats worldwide, causing economic damage and disrupting ecosystem processes. Introduced populations of L. humile and those of many other invasive ants tend to be unicolonial, forming expansive, multiqueened supercolonies that dominate native ant communities and challenge control practices in managed habitats. Argentine ant management typically entails the application of residual insecticide liquids, granules, or baits to only a portion of the colony, resulting in fairly rapid reinfestation. We suggest that prevailing control methodologies are incomplete and not compatible with the behavior, nesting habits, and population structure of this ant, and therefore, more aggressive management strategies are required. Successful eradication efforts against other invasive unicolonial ant species can provide useful insights for local-scale L. humile eradication. PMID:17877449

  6. Climate impacts on agriculture: Implications for forage and rangeland production

    SciTech Connect

    Izaurralde, Roberto C.; Thomson, Allison M.; Morgan, Jack; Fay, Philip; Polley, Wayne; Hatfield, Jerry L.

    2011-04-19

    Projections of temperature and precipitation patterns across the United States during the next 50 years anticipate a 1.5 to 2°C warming and a slight increase in precipitation as a result of global climate change. There have been relatively few studies of climate change impacts on pasture and rangeland (grazingland) species compared to those on crop species, despite the economic and ecological importance of the former. Here we review the literature on pastureland and rangeland species to rising CO2 and climate change (temperature, and precipitation) and discuss plant and management factors likely to influence pastureland and rangeland responses to change (e.g., community composition, plant competition, perennial growth habit, seasonal productivity, and management methods). Overall, the response of pasture species to increased [CO2] is consistent with the general response of C3 and C4 type vegetation, although significant exceptions exist. Both pastureland and rangeland species should exhibit an acceleration of metabolism and development due to earlier onset of spring green-up and longer growing seasons. However, in the studies reviewed here, C3 pasture species increased their photosynthetic rates by up to 40% while C4 species exhibited no increase in photosynthesis. In general, it is expected that increases in [CO2] and precipitation would enhance rangeland net primary production (NPP) while increased air temperatures would either increase or decrease NPP. Much of this uncertainty in response is due to uncertain future projections of precipitation, both globally and regionally. For example, if annual precipitation changes little or declines, rangeland plant response to warming temperatures and rising [CO2] may be neutral or may decline due to increased water stress. This review reveals the need for comprehensive studies of climate change impacts on the pasture ecosystem including grazing regimes, mutualistic relationships (e.g., plant roots-nematodes; N

  7. Argentine Valuation of the EQ-5D Health States

    PubMed Central

    Augustovski, Federico Ariel; Irazola, Vilma Edit; Velazquez, Alberto Pascual; Gibbons, Luz; Craig, Benjamin M.

    2013-01-01

    Objective To develop a set of EQ-5D health state values for the Argentine general population. Methods Consecutive subjects attending six primary care centers in Argentina were selected based on quota sampling and interviewed using the EuroQol Group protocol for measurement and valuation of health studies. Initially respondents were randomly assigned a unique card set; however, to improve efficiency, subjects were later randomly assigned to one of three fixed sets of EQ-5D states. Using the VAS and TTO responses for these states, we estimated a valuation model using ordinary least squares regression clustered by respondent. Predicted values for EQ-5D health states are compared to published values for the United States. Results Six hundred eleven subjects were interviewed by 14 trained interviewers, rendering 6,887 TTO and 6,892 VAS responses. The model had an R2 of 0.897 and 0.928 for TTO and VAS respectively. The mean absolute difference between observed and predicted values was 0.039 for TTO and 0.020 for VAS, each showing a Lin’s concordance coefficient above 0.98. United States and Argentine TTO predicted values were highly correlated (Pearson’s rho=0.963), though the average absolute difference was clinically meaningful (0.06), rejecting the US values for nearly two thirds of the states (62.8%). The Argentine population placed lower values on mild states and higher values on severe states. Conclusion This study provides an Argentine value set that could be used locally or regionally, with meaningful and significant differences with that of the US. Health policy in Latin America must incorporate local values for sovereignty and validity. PMID:19900257

  8. Argentine Population Genetic Structure: Large Variance in Amerindian Contribution

    PubMed Central

    Seldin, Michael F.; Tian, Chao; Shigeta, Russell; Scherbarth, Hugo R.; Silva, Gabriel; Belmont, John W.; Kittles, Rick; Gamron, Susana; Allevi, Alberto; Palatnik, Simon A.; Alvarellos, Alejandro; Paira, Sergio; Caprarulo, Cesar; Guillerón, Carolina; Catoggio, Luis J.; Prigione, Cristina; Berbotto, Guillermo A.; García, Mercedes A.; Perandones, Carlos E.; Pons-Estel, Bernardo A.; Alarcon-Riquelme, Marta E.

    2011-01-01

    Argentine population genetic structure was examined using a set of 78 ancestry informative markers (AIMs) to assess the contributions of European, Amerindian, and African ancestry in 94 individuals members of this population. Using the Bayesian clustering algorithm STRUCTURE, the mean European contribution was 78%, the Amerindian contribution was 19.4%, and the African contribution was 2.5%. Similar results were found using weighted least mean square method: European, 80.2%; Amerindian, 18.1%; and African, 1.7%. Consistent with previous studies the current results showed very few individuals (four of 94) with greater than 10% African admixture. Notably, when individual admixture was examined, the Amerindian and European admixture showed a very large variance and individual Amerindian contribution ranged from 1.5 to 84.5% in the 94 individual Argentine subjects. These results indicate that admixture must be considered when clinical epidemiology or case control genetic analyses are studied in this population. Moreover, the current study provides a set of informative SNPs that can be used to ascertain or control for this potentially hidden stratification. In addition, the large variance in admixture proportions in individual Argentine subjects shown by this study suggests that this population is appropriate for future admixture mapping studies. PMID:17177183

  9. Recovering plant biodiversity

    PubMed Central

    2011-01-01

    Studying recovering plant biodiversity on Mount Pinatubo may provide valuable insights that improve our understanding of recovery of other ecosystems following disturbances of all types. Ongoing sheet and rill erosion coupled with mass waste events in the unstable pyroclastic flow deposits persist, effectively re-setting primary succession at micro-landscape scale without affecting habitat level diversity. Spatial factors and micro-habitat diversity may exert more control over continued succession as the riparian systems become more deeply dissected and complex. The number of taxa within functional groups and conservation concerns are botanical issues that deserve further research. PMID:22019638

  10. Cattle-rangeland management practices and perceptions of pastoralists towards rangeland degradation in the Borana zone of southern Ethiopia.

    PubMed

    Solomon, T B; Snyman, H A; Smit, G N

    2007-03-01

    A survey was conducted in the Borana pastoral areas of southern Ethiopia to assess current livestock production systems, rangeland management practices and the perceptions of the pastoralists towards rangeland degradation. This information is considered vital to future pastoral development planning and interventions. Data were collected from a total of 20 villages that were identified from 5 peasant associations, namely Did Yabello, Moyatte, Did Harra, Dubuluk and Melbana. The average household size in the study area was 7.23. The majority of the pastoralists relied on both livestock and crop farming. The average livestock holding per household was 14 cattle, 10 goats, 6 sheep and 2 camels. Livestock holdings, with the exception of camels, has shown a declining trend over time. The two most important traditional rangeland management strategies adopted by the pastoralists included burning and mobility, but since 1974/75 burning has no longer been practised. With regard to mobility, the livestock herding falls in two categories, namely: home based and satellite herding. The former involves the herding of milking cows, calves and immature animals (<2 years) close to the encampments. The latter constitutes the herding of bulls and immatures (>2 years) further away from the encampments. Based on the pastoralists' perceptions, the major constraints on livestock production in descending order, were recurrent drought, feed and water scarcity, animal diseases, predators and communal land ownership. All the respondents considered the condition of the rangelands to have declined dramatically over time. In the past most development policies were based on equilibrium theories that opposed the communal use of the rangelands and traditional range management practices. The way in which the pastoral system affects the rangeland ecosystem functioning is contentious to this theory and the 'tragedy of the commons'. There was also a perceived problem of bush encroachment and the ban on

  11. Climate impacts on agriculture: Implications for forage and rangeland production

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Projections of temperature and precipitation patterns across the United States during the next 50 years anticipate a 1.5 to 2°C warming trend and a slight increase in precipitation. In general, the effects of climate change on crop species have been better studied than in pastureland and rangeland s...

  12. Selected Common Poisonous Plants of the United States' Rangelands

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Poisonous plants cause large economic losses throughout the rangelands of the world. In the 17 western states of the United States alone, it has been estimated that losses related to the ingestion of poisonous plants exceed $340 million annually. There are many plants that contribute to these large...

  13. Financial incentives: Possible options for sustainable rangeland management?

    PubMed

    Louhaichi, Mounir; Yigezu, Yigezu A; Werner, Jutta; Dashtseren, Lojoo; El-Shater, Tamer; Ahmed, Mohamed

    2016-09-15

    Large-scale mismanagement of natural resources emanating from lack of appropriate policies and regulatory framework is arguably one of the reasons that led to resource degradation and poor livelihoods in many countries in the Middle East and North Africa (MENA) region. Sustainable rangeland management practices (SRMPs) are considered to be a solution to feed shortages and rangeland degradation. However, the scope for SRMP adoption, has been a subject of debate. Using a case study from Syria and the application of the Minimum Data Analysis method (TOA-MD), this paper provides empirical evidence for ensuring wider adoption of SRMP. The paper argues that the introduction of financial incentives in the form of payments for agricultural-environmental services can increase the economic viability and enhance the adoption of SRMPs and is a better alternative to the unsustainable state subsidies for fodder purchases and barley cultivation on rangelands. Model results indicate that further investment in reasearch toward generating low cost technologies and tailored governance strategies including a financial incentive system would lead to better management of rangelands and improve livelihoods in the Syrian Badia. These findings are valuable for policy makers, donors as well as development and extension practitioners in the MENA region as they can better inform future courses of actions. PMID:27288553

  14. Rangeland ecology and management in a changing world

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rangeland ecological science and management over the past century has emphasized external human actions to supplement and direct natural ecological processes in the hope of achieving sustained production. The focus has usually been on an improve efficiency of production, generally achieved by addin...

  15. Germination and Persistence of Rangeland Grasses on Heavy Metal Soils

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Many acres of Western rangeland have been degraded by mining and other land disturbances which often results in soil with elevated salinity, increased acidity, high levels of sodium, metals, and decreased nutrient availability. Chemical amendment of degraded soils followed by reseeding has resulted...

  16. Integrated approach to cheatgrass suppression on Great Basin Rangelands

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cheatgrass (Bromus tectorum), native to central Eurasia, is a highly invasive annual grass that has invaded millions of hectares of rangelands throughout the Intermountain West. Cheatgrass has revolutionized secondary succession by providing a fine-textured, early-maturing fuel that increases the c...

  17. EXPERIENCING THE SUCCESS AND FAILURES OF RANGELAND RESTORATION/REVEGETATION

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Anyone who has ever attempted to restore (native species) or revegetate (introduced species) disturbed arid rangelands knows the frustration inherent in such efforts. Exotic species such as cheatgrass (Bromus tectorum) and medusahead (Taeniatherum caput-medusae) significantly add to the complicatio...

  18. The importance of seed germination in rangeland research

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The USDA, Agricultural Research Service (ARS)/ Great Basin Rangelands Research Unit, Wildland Seed Laboratory, located in Reno, NV, has been studying seed germination for the past 40 years. The wildland seed laboratory has collected, processed, and quantified germination characteristics of hundreds...

  19. SELECTIVE CONTROL OF RANGELAND GRASSHOPPERS WITH PRESCRIBED FIRE

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Grasshoppers (Orthoptera: Acrididae) are considered among the most damaging rangeland pests, but are necessary for the survival of many wildlife species. Most grasshoppers are innocuous, but control with insecticides is non-discriminatory among species. The objectives were to evaluate the effects ...

  20. THE EFFECTS OF INTERSEEDED ALFALFA ON NATIVE RANGELAND SOILS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rising atmospheric CO2 concentration impacts on global change have spurred research in the field of soil carbon sequestration. Rangeland soils, generally nitrogen and water deficient, have shown potential as a sink for carbon through management practices and plant community improvement. Introducing ...

  1. Impacts of feral horse use on rangelands and riparian areas

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Feral (wild) horse impacts on rangelands and riparian areas are largely unknown. The impacts of feral horses are often indistinguishable from domestic livestock impacts because livestock grazing occurs across most horse herd management areas. However, the Sheldon National Wildlife Refuge has a lar...

  2. Cattle as ecosystem engineers: New grazing management enhances rangeland biodiversity

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A confluence of factors has shaped the composition and structure of vegetation on rangelands in the American West. These factors include climate, soils, topography, history of grazing and fire (both wildfire and prescribed fire) as well as legacy effects from prior land management practices. Despite...

  3. Integrating Weed Management and Restoration on Western Rangelands

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In 2003, we began experiments to control cheatgrass and restore native species on Great Basin Rangelands. Experiments, which tested transitional species and functional groups on restoration, were established at eight sites in Nevada, Oregon, Idaho, and Utah. After two years of trials, accessions of ...

  4. Brush management as a rangeland conservation strategy: A critical evaluation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    One of the most striking land cover changes on rangelands worldwide over the past 150 years has been the proliferation of trees and shrubs at the expense of perennial grasses. Woody plant encroachment represents a threat to grassland, shrub-steppe and savanna ecosystems and the plants and animals n...

  5. Hydrology, erosion, and soil interrelationships after rangeland wildfire

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Wildfire is a major ecological process and management issue on rangelands throughout the western United States. Fire suppression and land management activities over the past century have disrupted natural fire cycles which can result in more intense and sometimes catastrophic events. Managers are ...

  6. Revegetating medusahead-invaded sagebrush rangelands in the intermountain west

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Revegetation of medusahead-invaded rangeland is needed to increase forage production, decrease the risk of wildfires, and improve wildlife habitat. Successful revegetation starts with effective control of medusahead. Prescribed burning followed by a fall application of a pre-emergent herbicide has...

  7. Response of native ungulates to drought in semiarid Kenyan rangeland

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The distribution and abundance of native ungulates were measured on commercially-managed, semiarid rangeland in central Kenya over a 3-year period that encompassed severe drought and above-average rainfall. Ungulate biomass density averaged 7556 kg/km2 over the study and was dominated by elephant (L...

  8. Monitoring Rangeland Health With MODIS Vegetation Index Data

    NASA Astrophysics Data System (ADS)

    Brown, J. F.

    2004-12-01

    Rangelands cover approximately one third of the land area of the conterminous U.S. These lands supply much of the forage for the U.S. cattle industry. Large area monitoring of these vast expanses of range has proved challenging since most of these lands are in the western U.S., are relatively sparsely populated, and are not well covered by meteorological weather stations. Improvements in the spatial and temporal precision of rangeland health information would be useful both for the cattle industry and for scientific studies of soil erosion, water runoff, ecosystem health, and carbon cycling. Optical multispectral remote sensing data from satellites are an objective source of synoptic, timely information for monitoring rangeland health. The objective of this study is to develop and evaluate a method for measuring and monitoring rangeland health over large areas. In the past, data collected by the Advanced Very High Resolution Radiometer has proved useful for this purpose, however the basic 1 km spatial resolution is not ideal when scaling up from ground observations. This study assesses MODIS 250 meter resolution vegetation index data for this purpose. MODIS data not only have finer spatial resolution and improved geolocation, but they also exhibit enhanced vegetation sensitivity and minimized variations associated with external atmospheric and non-atmospheric effects. Ground data collected over 51 sites in western South Dakota over four years are used as training for regression tree models of range health. Range health maps for the growing season derived from the models are presented and evaluated.

  9. Simplifying ecological site verification, rangeland health assessments, and monitoring

    Technology Transfer Automated Retrieval System (TEKTRAN)

    During the past several decades, scientists and land managers in North America have increasingly recognized the importance of rangeland assessment relative to ecological potential based on soil and climate. The adoption of the site potential based “ecological site” system was recently formalized in ...

  10. Ecosystem Services from U.S. Rangelands: A Synthesis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The over 300 million ha of public and private rangelands in the United States are characterized by low and variable precipitation, nutrient-poor soils, and high spatial and temporal variability in plant production. This land type has provided a variety of goods and services, with the provisioning of...

  11. Prioritizing rangeland research and restoration based on societal outcomes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rangeland ecological research is generally driven by interest in a particular pattern, process or organism, by a desire to maximize a particular ecosystem service (such as livestock production) at a specific location, or by an interest in the effects of a particular management system on soils, veget...

  12. Are we ready for the (range)land revolution?

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rangeland scientists have a tremendous amount of knowledge that could ensure that the transition from livestock production to other land uses is as sustainable as possible, while maintaining livestock production systems where they are the most biophysically, socially, culturally and economically sus...

  13. Germination and Persistence of Rangeland Grasses on Heavy Metal Soils

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Many of acres of Western rangeland have been degraded by mining and other land disturbances which often result in soil with elevated salinity, increased acidity, high levels of sodium, metals, and decreased nutrient availability. Chemical amendment of degraded soils followed by reseeding has result...

  14. A PHYSIOLOGICAL BASIS FOR CONTROLLING LEAFY SPURGE ON NEBRASKA RANGELAND

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Leafy spurge is a non-native perennial forb that invades rangeland and pasture in the central and northern Great Plains of the U.S. and Canada. It quickly increases in pastures, reduces available forage by displacing desirable plants and changing species composition, and may reduce forage use by ca...

  15. Slope impacts on concentrated flow hydraulics in rangeland

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Several studies have been conducted to describe rill or concentrated flow hydraulics. However, most of these studies used data obtained from either laboratory experiments or field sites located on gently sloping crop lands. The data sets in the few rangeland field studies conducted did not cover a ...

  16. Revegetating medusahead-invaded sagebrush rangelands in the Intermountain West

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Revegetation of medusahead-invaded rangeland is needed to increase forage production, decrease the risk of wildfires, and improve wildlife habitat. Successful revegetation starts with effective control of medusahead. Prescribed burning followed by a fall application of a pre-emergent herbicide has...

  17. Opportunities for increasing utility of models for rangeland management

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A tremendous need exists for ecosystem models to assist in rangeland management, but the utility of models developed to date has been minimal for enterprise-level decision making. Three areas in which models have had limited effectiveness for land managers are 1) addressing contemporary needs associ...

  18. Medusahead In Sagebrush Steppe Rangelands: Control, Restoration, And Prevention.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Medusahead is a non-native annual grass that is degrading sagebrush rangelands. However, information on its management is not widely available to land managers. We compiled results from previous studies to provide information on controlling, restoring, and preventing medusahead infestations in sag...

  19. Ecologically appropriate plant materials for functional restoration of rangelands

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Ecosystems of rangelands targeted for restoration have often been modified, hindering restoration efforts. WEhile local adaptation has long been used as an argument for the exclusive use of local plant materials, recent meta-analysis results indicate that general adaptation across a variety of envi...

  20. Rangelands and climate change: A synthesis and challenges

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Climate change, along with other aspects of global change, represents a great challenge to rangeland management in the coming century. Coping with this challenge requires collaboration among scientists, managers and policy makers to develop new tools and management systems. This collaboration shou...

  1. Fire, plant invasions, and erosion events on western rangelands

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Millions of hectares of rangeland in the western United States have been invaded by annual and woody plants that have increased the role of wildland fire. Altered fire regimes pose significant implications for runoff and erosion. In this paper we synthesize what is known about fire impacts on rang...

  2. Impacts of feral horse use on rangelands and riparian areas

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Feral (wild) horse impacts on rangelands and riparian areas are largely unknown. The impacts of feral horses are often indistinguishable from domestic livestock impacts because livestock grazing occurs across most horse herd management areas. However, the Sheldon National Wildlife Refuge has a large...

  3. Importance of shrub restoration on great basin rangelands

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The recognition of brush species and the browse these plants provide as an important component of rangeland production was often overlooked in land management for some time. Even after the birth of range management in the early twentieth century, herbaceous species were considered the basic componen...

  4. Making soil health a part of rangeland management

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Soil health describes the ability of a soil to function at its potential, specifically “The capacity of a soil to function as a vital, living ecosystem that sustains plants, animals and humans”. The objectives of this paper are to 1) contextualize rangeland soil health by examining the common defini...

  5. Sound management may sequester methane in grazed rangeland ecosystems

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Considering their contribution to global warming, the sources and sinks of methane (CH4) should be accounted when undertaking a greenhouse gas inventory for grazed rangeland ecosystems. The aim of this study was to evaluate the mitigation potential of current ecological management programs implement...

  6. Incorporating plant mortality and recruitment into rangeland management and assessment

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rangeland management is largely focused on managing vegetation change. Objectives may include managing against change if the desired vegetation is in place, or attempting to create a shift in vegetation if the desired state is not present. Describing potential vegetation states and requirements fo...

  7. A simple graphical approach to quantitative monitoring of rangelands

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Long-term monitoring is an essential part of good rangeland management – but is often overlooked because managers perceive it to be complicated, technical, or time-consuming. We introduce a quick, easy, and quantitative approach to monitoring changes in plant and ground cover, plant density, and veg...

  8. PROCESS OF SELECTING INDICATORS FOR MONITORING CONDITIONS OF RANGELAND HEALTH

    EPA Science Inventory

    This paper reports on a process for selecting a suite of indicators that, in combination, can be useful in assessing the ecological conditions of rangelands. onceptual models that depict the structural and functional properties of ecological processes were used to show the linkag...

  9. Nitrogen uptake: invasive annual vs. native perennial rangeland grasses

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Incursion into perennial dominated rangelands of the Intermountain West by two winter exotic annual grasses, cheatgrass and medusahead, is one of the most serious plant invasion in North America. The invasions have decreased productivity and biological diversity and increased the frequency of range...

  10. Integrated approach to cheatgrass suppression on great basin rangelands

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cheatgrass (Bromus tectorum), native to central Eurasia, is a highly invasive annual grass that has invaded millions of hectares of rangelands throughout the Intermountain West. Cheatgrass has revolutionized secondary succession by providing a fine-textured, early-maturing fuel that increases the c...

  11. Managing the herbage utilisation and intake by cattle grazing rangelands

    Technology Transfer Automated Retrieval System (TEKTRAN)

    To be able to predict the performance of grazing cattle in extensive rangeland environments, herbage intake is paramount because it quantifies energy intake and performance. Nutrient demand of the animals is the major driver of herbage intake and characteristics of the sward dictate how this demand...

  12. Rangeland CEAP: An assessment of natural resources conservation service practices

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The NRCS uses science-based technology to provide conservation planning and assistance to land owners and land operators to maintain productive lands and healthy ecosystems. Evaluating science-based literature on effectiveness of rangeland conservation practices is an important first step as it pro...

  13. Parameterization of erodibility in the Rangeland Hydrology and Erosion Model

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The magnitude of erosion from a hillslope is governed by the availability of sediment and connectivity of runoff and erosion processes. For undisturbed rangelands, sediment is primarily detached and transported by rainsplash and sheetflow (splash-sheet) processes in isolated bare batches, but sedime...

  14. The Importance of Seed Germination in Rangeland Research

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The USDA, Agricultural Research Service (ARS)/ Great Basin Rangelands Research Unit, Wildland Seed Laboratory, located in Reno, NV, has been studying seed germination for the past 40 years. The wildland seed laboratory has collected, processed, and quantified germination characteristics of hundreds...

  15. Development of a UAV rangeland remote sensing capability

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Starting in 2000, experiments have been conducted at the Jornada Experimental Range near Las Cruces, NM to evaluate the utility of Unmanned Aerial Vehicles (UAVs) for applications on arid rangelands. When compared to all types of remote sensing research ongoing at Jornada and other locations, UAVs h...

  16. Rangeland Ecosystem Services: Nature's Supply and Human's Demands

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Ecosystem services are the benefits that society receives from nature and they include the regulation of climate, the pollination of crops, the provisioning of intellectual inspiration and recreational environment, as well as many essential goods such as food, fiber, and wood. Rangeland ecosystem se...

  17. A site-based approach to delivering rangeland ecosystem services

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rangeland ecosystems are capable of providing an array of ecosystem services important to the wellbeing of society. Some of these services (e.g. meat, fibre) are transported to markets and their quantity, quality and value are established via a set of widely accepted standards. Other services (e.g. ...

  18. Giant mudwaves in the Northern Argentine Basin: born and buried by bottom currents

    NASA Astrophysics Data System (ADS)

    Borisov, Dmitrii; Murdmaa, Ivar; Ivanova, Elena; Levchenko, Oleg

    2014-05-01

    New sedimentary records and very high resolution seismic profiles collected during four cruises of the RV "Akademik Ioffe" (2011-2013) were correlated with seismic, multibeam and coring data obtained during cruises of the RV "Robert Conrad", "Knorr", "Meteor". A complex analysis of the geological-geophysical data revealed an extensive field of giant mudwaves (48 000 km2) in the northwestern Argentine Basin, South Atlantic. The symmetric waves up to 60 m in height and 4000 m in wavelength are oriented roughly parallel to contours. They partly cover the Santa Catarina Plateau and extend through the Santos Basin to the Sao Paulo Plateau. The mudwaves field is traced at the depth range from 3400 to 4000 m and divided into buried (northern) and non-buried (southern) parts. The non-buried sediment waves cover the surface of the huge drift in the Santa Catarina Plateau. The wave height increases from the drift summit to its flanks and decreases at the foot. Two cores retrieved from the drift top and its northern flank recovered muddy contourites with a greater amount of silt-size material in the core from the drift flank. The age of the recovered sediments is at least 130 ka. In the northern Santos basin, the sediment waves are buried under a large lens-like sediment body (drift?) inclined at the margins. Cores obtained from the buried part of the mudwaves field recovered an intercalation of hemipelagic clay and silty-clay contourite. The age of recovered sediments does not exceed 150 ka (Bleil et al., 1993). Contourites deposition in the study area is related to the activity of the Antarctic bottom water (AABW) contour current. The AABW flow is considered to be divided into two branches by the Santa Catarina Plateau. We suggest that this topographic obstacle causes a flow velocity increase. Wave height and grain-size variations indicate higher bottom current velocities at the plateau flanks and relative tranquil conditions at the flat summit of the plateau. The symmetric

  19. Insights into the Carbon Sequestration Potential of Rangelands Through Measurement and Modeling of Differently Managed Pastures

    NASA Astrophysics Data System (ADS)

    Owen, J. J.; Hartman, M.; Parton, W. J.; Silver, W. L.

    2014-12-01

    generally declined due to a legacy effect of the historical shift in vegetation from perennial to annual grasses, and did not recover over the timespan considered here. These results demonstrate the potential of manure amendment to increase soil C in some rangelands and the ability of DayCent to reasonably approximate changes in soil C in response to management.

  20. Deterrency and Toxicity of Essential Oils to Argentine and Red Imported Fire Ants (Hymenoptera: Formicidae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Laboratory assays were conducted to evaluate deterrency and contact toxicity of six essential oils to the Argentine ant, Linepithema humile (Mayr), and the red imported fire ant, Solenopsis invicta Buren. In choice tests, both Argentine ants and fire ants crossed barriers treated with multiple rates...

  1. Trail pheromone of the Argentine ant, Linepithema humile (Mayr) (Hymenoptera: Formicidae).

    PubMed

    Choe, Dong-Hwan; Villafuerte, David B; Tsutsui, Neil D

    2012-01-01

    The Argentine ant (Linepithema humile) is recognized as one of the world's most damaging invasive species. One reason for the ecological dominance of introduced Argentine ant populations is their ability to dominate food and habitat resources through the rapid mobilization and recruitment of thousands of workers. More than 30 years ago, studies showed that (Z)-9-hexadecenal strongly attracted Argentine ant workers in a multi-choice olfactometer, suggesting that (Z)-9-hexadecenal might be the trail pheromone, or a component of a trail pheromone mixture. Since then, numerous studies have considered (Z)-9-hexadecenal as the key component of the Argentine ant trails. Here, we report the first chemical analyses of the trails laid by living Argentine ants and find that (Z)-9-hexadecenal is not present in a detectible quantity. Instead, two iridoids, dolichodial and iridomyrmecin, appear to be the primary chemical constituents of the trails. Laboratory choice tests confirmed that Argentine ants were attracted to artificial trails comprised of these two chemicals significantly more often than control trails. Although (Z)-9-hexadecenal was not detected in natural trails, supplementation of artificial dolichodial+iridomyrmecin trails with an extremely low concentraion of (Z)-9-hexadecenal did increase the efficacy of the trail-following behavior. In stark contrast with previous dogma, our study suggests that dolichodial and iridomyrmecin are major components of the Argentine ant trail pheromone. (Z)-9-hexadecenal may act in an additive manner with these iridoids, but it does not occur in detectable quantities in Argentine ant recruitment trails. PMID:23028739

  2. PROCESS FOR RECOVERING URANIUM

    DOEpatents

    MacWood, G.E.; Wilder, C.D.; Altman, D.

    1959-03-24

    A process is described for recovering uranium from deposits on stainless steel liner surfaces of calutrons. The deposit is removed from the stainless steel surface by washing with aqueous nitric acid. The solution obtained containing uranium, chromium, nickels copper, and iron is treated with excess of ammonium hydroxide to precipitatc the uranium, irons and chromium and convert thc nickel and copper to soluble ammonia complexions. The precipitated material is removed, dried, and treated with carbon tetrachloride at an elevated temperature of about 500 to 600 deg C to form a vapor mixture of UCl/sub 4/, UCl/sub 5/, FeCl/ sub 3/, and CrCl/sub 4/. The UCl/sub 4/ is separated from this vapor mixture by selective fractional condensation at a temprrature of about 300 to400 deg C.

  3. Process for recovering uranium

    DOEpatents

    MacWood, G. E.; Wilder, C. D.; Altman, D.

    1959-03-24

    A process useful in recovering uranium from deposits on stainless steel liner surfaces of calutrons is presented. The deposit is removed from the stainless steel surface by washing with aqueous nitric acid. The solution obtained containing uranium, chromium, nickel, copper, and iron is treated with an excess of ammonium hydroxide to precipitnte the uranium, iron, and chromium and convert the nickel and copper to soluble ammonio complexions. The precipitated material is removed, dried and treated with carbon tetrachloride at an elevated temperature of about 500 to 600 deg C to form a vapor mixture of UCl/ sub 4/, UCl/sub 5/, FeCl/sub 3/, and CrCl/sub 4/. The UCl/sub 4/ is separated from this vapor mixture by selective fractional condensation at a temperature of about 500 to 400 deg C.

  4. METHOD OF RECOVERING THORIUM

    DOEpatents

    Fisher, R.W.

    1957-12-10

    A method is described for recovering thorium from impurities found in a slag containing thorium and said impurities, comprising leaching a composition containing thorium with water, removing the water solution, treating the residue with hydrochloric acid, separating the solution from the insoluble residue, adjusting its acidity to 1 to 3 normal, adding oxalic acid, and thereafter separating the precipitated thorium oxalate digesting the residue from the hydrochloric acid treatment with a strong solution of sodium hydroxide at an elevated temperature, removing said solution and treating the insoluble residue with hydrochloric acid, separating the solution from the insoluble residue, adjusting the acidity of this solution to 1 to 3 normal, adding nitric acid to oxidize the iron present, adding oxalic acid and thereafter separating the thorium oxalate thus precipitated.

  5. Rangelands, pastoralists and governments: interlinked systems of people and nature.

    PubMed

    Walker, Brian H; Janssen, Marco A

    2002-05-29

    We analyse commercially operated rangelands as coupled systems of people and nature. The biophysical components include: (i) the reduction and recovery of potential primary production, reflected as changes in grass production per unit of rainfall; (ii) changes in woody plants dependent on the grazing and fire regimes; and (iii) livestock and wool dynamics influenced by season, condition of the rangeland and numbers of wild and feral animals. The social components include the managers, who vary with regard to a range of cognitive abilities and lifestyle choices, and the regulators who vary in regard to policy goals. We compare agent-based and optimization models of a rangeland system. The agent-based model leads to recognition that policies select for certain management practices by creating a template that governs the trajectories of the behaviour of individuals, learning, and overall system dynamics. Conservative regulations reduce short-term loss in production but also restrict learning. A free-market environment leads to severe degradation but the surviving pastoralists perform well under subsequent variable conditions. The challenge for policy makers is to balance the needs for learning and for preventing excessive degradation. A genetic algorithm model optimizing for net discounted income and based on a population of management solutions (stocking rate, how much to suppress fire, etc.) indicates that robust solutions lead to a loss of about 40% compared with solutions where the sequence of rainfall was known in advance: this is a similar figure to that obtained from the agent-based model. We conclude that, on the basis of Levin's three criteria, rangelands with their livestock and human managers do constitute complex adaptive systems. If this is so, then command-and-control approaches to rangeland policy and management are bound to fail. PMID:12079532

  6. Evaluating the capability of the enhanced Rangeland Hydrology and Erosion Model (RHEM) for modeling the soil erosion impact of disturbance on rangelands

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In this study, enhancement of the application of RHEM has been made using a new approach for predicting concentrated flow erosion in order to expand its applicability to disturbed rangelands. The enhanced model was conceptualized based on observations and results of experimental studies on rangeland...

  7. PROCESS OF RECOVERING URANIUM

    DOEpatents

    Kilner, S.B.

    1959-12-29

    A method is presented for separating and recovering uranium from a complex mixure of impurities. The uranium is dissolved to produce an aqueous acidic solution including various impurities. In accordance with one method, with the uranium in the uranyl state, hydrogen cyanide is introduced into the solution to complex the impurities. Subsequently, ammonia is added to the solution to precipitate the uraniunn as ammonium diuranate away from the impurities in the solution. Alternatively, the uranium is precipitated by adding an alkaline metal hydroxide. In accordance with the second method, the uranium is reduced to the uranous state in the solution. The reduced solution is then treated with solid alkali metal cyanide sufficient to render the solution about 0.1 to 1.0 N in cyanide ions whereat cyanide complex ions of the metal impurities are produced and the uranium is simultaneously precipituted as uranous hydroxide. Alternatively, hydrogen cyanide may be added to the reduced solution and the uranium precipitated subsequently by adding ammonium hydroxide or an alkali metal hydroxide. Other refinements of the method are also disclosed.

  8. Rangeland degradation assessment: a new strategy based on indigenous ecological knowledge of pastoralists

    NASA Astrophysics Data System (ADS)

    Behmanesh, B.; Barani, H.; Abedi Sarvestani, A.; Shahraki, M. R.; Sharafatmandrad, M.

    2015-10-01

    In the changing world, the prevalence of land degradation is becoming a serious problem worldwide especially in countries with arid and semiarid rangelands. There are many techniques to assess rangeland degradation but most of them rely on classic science. So a study was conducted to find out how indigenous people assess rangeland degradation and how their ecological knowledge can be used for rangeland degradation assessment. We interviewed pastoralists of two sites (Mirza-Baylu and Dasht) where part of both areas is located in Golestan National Park (NE Iran). A structured questionnaire was designed based on some indicators taken from literature and also primary discussions with pastoralists in order to evaluate land degradation. A qualitative Likert scale was used for scoring rangeland degradation indicators. The results revealed that pastoralist pay first attention to edaphic indicators than vegetative and other indicators. There were significant differences between inside and outside of the park in rangeland degradation indicators for both sites. The results show that the rangelands outside the park in both sites were degraded compare to inside the park especially in the areas near to villages. It can be concluded that pastoralists own a vast amount of knowledge on the vegetation and grazing animal habits that can be used in rangeland degradation assessment and it is necessary to document their ecological indigenous knowledge and involve them in rangeland degradation assessment process.

  9. The swift fox in rangeland and cropland in western Kansas: Relative abundance, mortality, and body size

    USGS Publications Warehouse

    Matlack, R.S.; Gipson, P.S.; Kaufman, D.W.

    2000-01-01

    We assessed suitability of cropland and shortgrass rangeland for swift foxes (Vulpes velox) in western Kansas. Relative abundance and survival were similar for foxes in rangeland and cropland. Mortality resulting from non-traumatic causes, coyotes, and motor vehicles differed significantly between habitats. Predation by coyotes, motor vehicles, and non-traumatic causes were responsible for 45%, 36%, and 18%, respectively, of 11 deaths in rangeland and 20%, 10%, and 70%, respectively, of 10 deaths in cropland. Swift foxes in rangeland were larger and in better condition than those in cropland. Males were larger than females based on mass, standardized mass (mass/body length), body length, hindfoot length, and ear length.

  10. Trail Pheromone Disruption of Argentine Ant Trail Formation and Foraging

    USGS Publications Warehouse

    Suckling, D.M.; Peck, R.W.; Stringer, L.D.; Snook, K.; Banko, P.C.

    2010-01-01

    Trail pheromone disruption of invasive ants is a novel tactic that builds on the development of pheromone-based pest management in other insects. Argentine ant trail pheromone, (Z)-9-hexadecenal, was formulated as a micro-encapsulated sprayable particle and applied against Argentine ant populations in 400 m2 field plots in Hawai'i Volcanoes National Park. A widely dispersed point source strategy for trail pheromone disruption was used. Traffic rates of ants in bioassays of treated filter paper, protected from rainfall and sunlight, indicated the presence of behaviorally significant quantities of pheromone being released from the formulation for up to 59 days. The proportion of plots, under trade wind conditions (2-3 m s-1), with visible trails was reduced for up to 14 days following treatment, and the number of foraging ants at randomly placed tuna-bait cards was similarly reduced. The success of these trail pheromone disruption trials in a natural ecosystem highlights the potential of this method for control of invasive ant species in this and other environments. ?? Springer Science+Business Media, LLC 2010.

  11. Trail pheromone disruption of Argentine ant trail formation and foraging.

    PubMed

    Suckling, David Maxwell; Peck, Robert W; Stringer, Lloyd D; Snook, Kirsten; Banko, Paul C

    2010-01-01

    Trail pheromone disruption of invasive ants is a novel tactic that builds on the development of pheromone-based pest management in other insects. Argentine ant trail pheromone, (Z)-9-hexadecenal, was formulated as a micro-encapsulated sprayable particle and applied against Argentine ant populations in 400 m2 field plots in Hawai'i Volcanoes National Park. A widely dispersed point source strategy for trail pheromone disruption was used. Traffic rates of ants in bioassays of treated filter paper, protected from rainfall and sunlight, indicated the presence of behaviorally significant quantities of pheromone being released from the formulation for up to 59 days. The proportion of plots, under trade wind conditions (2–3 m s−1), with visible trails was reduced for up to 14 days following treatment, and the number of foraging ants at randomly placed tuna-bait cards was similarly reduced. The success of these trail pheromone disruption trials in a natural ecosystem highlights the potential of this method for control of invasive ant species in this and other environments. PMID:20077128

  12. Rangeland health attributes and indicators for qualitative assessment

    USGS Publications Warehouse

    Pyke, David A.; Herrick, J.E.; Pellant, Mike

    2002-01-01

    Panels of experts from the Society for Range Management and the National Research Council proposed that status of rangeland ecosystems could be ascertained by evaluating an ecological site's potential to conserve soil resources and by a series of indicators for ecosystem processes and site stability. Using these recommendations as a starting point, we developed a rapid, qualitative method for assessing a moment-in-time status of rangelands. Evaluators rate 17 indicators to assess 3 ecosystem attributes (soil and site stability, hydrologic function, and biotic integrity) for a given location. Indicators include rills, water flow patterns, pedestals and terracettes, bare ground, gullies, wind scour and depositional areas, litter movement, soil resistance to erosion, soil surface loss or degradation, plant composition relative to infiltration, soil compaction, plant functional/structural groups, plant mortality, litter amount, annual production, invasive plants, and reproductive capability. In this paper, we detail the development and evolution of the technique and introduce a modified ecological reference worksheet that documents the expected presence and amount of each indicator on the ecological site. In addition, we review the intended applications for this technique and clarify the differences between assessment and monitoring that lead us to recommend this technique be used for moment-in-time assessments and not be used for temporal monitoring of rangeland status. Lastly, we propose a mechanism for adapting and modifying this technique to reflect improvements in understanding of ecosystem processes. We support the need for quantitative measures for monitoring rangeland health and propose some measures that we believe may address some of the 17 indicators.

  13. Decision methodology for the resource utilization of rangeland watersheds

    SciTech Connect

    Khalili, D.

    1986-01-01

    Degradation of rangeland resources leading to the desertification process is viewed in terms of human and climatic influences. While climatic impacts are important, resource utilization as practiced by man is the major cause of desertification. A multi-objective decision methodology developed here is intended for the analysis of alternative management plans of rangeland watersheds under climatic variability. First, a system model is employed to portray the dynamics of a rangeland as it would respond to climatic changes and different grazing intensities. This approach allows for an interaction of inputs such as rainfall, solar radiation, and temperature with the sate of the system which is a range condition index, and with outputs such as production and sediment yield. A simulation package is developed to implement the system model by actually using available data and providing some output values for production and sediment yield. At this stage a number of alternative management plans are identified. The information obtained from the simulation as well as other information of interest are represented by performance criteria, leading to an array of alternative versus criteria. Then, management plans need to be evaluated as they would impact the criteria. A multi-objective decision-making technique is selected to perform the analysis for an identification of preferred management alternatives.

  14. Assessing the impacts of livestock production on biodiversity in rangeland ecosystems

    PubMed Central

    Alkemade, Rob; Reid, Robin S.; van den Berg, Maurits; de Leeuw, Jan; Jeuken, Michel

    2013-01-01

    Biodiversity in rangelands is decreasing, due to intense utilization for livestock production and conversion of rangeland into cropland; yet the outlook of rangeland biodiversity has not been considered in view of future global demand for food. Here we assess the impact of future livestock production on the global rangelands area and their biodiversity. First we formalized existing knowledge about livestock grazing impacts on biodiversity, expressed in mean species abundance (MSA) of the original rangeland native species assemblages, through metaanalysis of peer-reviewed literature. MSA values, ranging from 1 in natural rangelands to 0.3 in man-made grasslands, were entered in the IMAGE-GLOBIO model. This model was used to assess the impact of change in food demand and livestock production on future rangeland biodiversity. The model revealed remarkable regional variation in impact on rangeland area and MSA between two agricultural production scenarios. The area of used rangelands slightly increases globally between 2000 and 2050 in the baseline scenario and reduces under a scenario of enhanced uptake of resource-efficient production technologies increasing production [high levels of agricultural knowledge, science, and technology (high-AKST)], particularly in Africa. Both scenarios suggest a global decrease in MSA for rangelands until 2050. The contribution of livestock grazing to MSA loss is, however, expected to diminish after 2030, in particular in Africa under the high-AKST scenario. Policies fostering agricultural intensification can reduce the overall pressure on rangeland biodiversity, but additional measures, addressing factors such as climate change and infrastructural development, are necessary to totally halt biodiversity loss. PMID:22308313

  15. Response to Barnes et al. Letter to the Editor (reference to Bracy Knight et al. 2011 paper in Rangelands)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Our original article “Cross-fencing on private US rangelands: financial costs and producer risks” (Bracy Knight et al. 2011 Rangelands 33(2):41-44), demonstrated that producers incur high initial and continuing long-term costs associated with cross-fencing rangelands. While these costs can be partia...

  16. Activity of Bifenthrin, Chlorfenapyr, Fipronil, and Thiamethoxam against Argentine Ants (Hymenoptera: Formicidae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bifenthrin, chlorfenapyr, fipronil, and thiamethoxam were evaluated for activity against the Argentine ant, Linepithema humile (Mayr). Mobility impairment and lethal times were determined following topical treatments. Ants were immobilized most quickly by bifenthrin, followed by chlorfenapyr and th...

  17. Editorial: a scientifically rigorous and user-friendly Rangeland Ecology & Management

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rangeland Ecology and Management (REM) is the premier journal for communication of science-based knowledge and for fostering both innovation and rigor in our stewardship of the world’s rangelands. REM is critical to the mission of the Society for Range Management and has had increasing scientific im...

  18. Discussion of submitted posters for Section 2.3 (Rangeland Germplasm Resources)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    As part of the IX International Rangeland Congress held in Rosario, Argentina, a total of 70 posters from 17 countries were submitted to Section 2.3 (Rangeland Germplasm Resources). These posters documented research conducted in five major regions of the world: South America, North America, Africa...

  19. Concentrated flow erodibility for physically-based erosion models: temporal variability in disturbed and undisturbed rangelands

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Current physically based overland flow erosion models for rangeland application do not separate disturbed and undisturbed conditions in modeling concentrated flow erosion. In this study, concentrated flow simulations on disturbed and undisturbed rangelands were used to estimate the erodibility and t...

  20. Fire severity modeling of sagebrush-steppe rangelands in Southeastern Idaho

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Wildland fires are common in rangelands throughout the world and the sagebrush steppe ecosystem of the Intermountain West is no exception. The potential for high severity fires to affect long-term changes in rangelands is considerable and for this reason, assessing fire severity shortly after the fi...

  1. Cooperative prevention systems to protect rangelands from the spread of invasive plants

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Invasive plants continue to spread and impact rangelands in the western United States. Fortunately, many rangeland ecosystems still remain invasive weed-free.Cooperative prevention systems can safeguard these remaining areas. Local-level weed prevention areas (WPAs) prioritize prevention in the larg...

  2. Estimating rangeland runoff, soil erosion, and salt mobility and transport processes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Over 55% of sediment and salts entering the Colorado River are derived from accelerated soil erosion from federal rangelands with damages estimated to be $385 million per year. About 55% of the loading is derived from rangelands. This suggests a significant potential to reduce dissolved-solids loa...

  3. Hydrologic ramifications of an increased role of wildland fire across the rangeland-dry forest continuum

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The increased role of wildland fire across the rangeland-dry forest continuum in the western United States (US) presents landscape-scale consequences relative runoff and erosion. Much of the Intermountain West now exists in a state in which rangeland and woodland wildfires stimulated by invasive che...

  4. Hydrologic vulnerability of western US rangelands in the wake of woodland encroachment and increasing wildfire activity

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Pinyon and juniper woodlands have dramatically increased their range in the past 150 years and currently occupy more than 30 million ha of the western US. Range expansion has primarily occurred through encroachment into sagebrush rangelands. Woodland expansion and infill on western rangelands have a...

  5. Western and Searls Prairie Clovers: North American Legumes for Rangeland Revegetation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Only a few North American legumes are commercially available for rangeland revegetation in the western U.S. Western prairie clover (Dalea ornata) and Searls prairie clover (D. searlsiae) are two North American legumes that hold promise for use in rangeland revegetation and conservation. Seeds of w...

  6. Earth stewardship on rangelands: Coping with ecological, economic, and political marginality

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rangelands encompass 30-40 percent of Earth's land surface and support 1-2 billion people. Their predominant use is extensive livestock production by pastoralists and ranchers. But rangelands are characterized by ecological, economic, and political marginality, and higher-value, more intensive land ...

  7. Plant/life form considerations in the rangeland hydrology and erosion model (RHEM)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Resilience of rangeland to erosion has largely been attributed to adequate plant cover; however, plant life/growth form, and individual species presence can have a dramatic effect on hydrologic and erosion dynamics on rangelands. Plant life/growth form refers to genetic tendency of a plant to grow i...

  8. Hydrologic effects of fire in sagebrush plant communities: Implications for rangeland hydrology and erosion modeling

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Millions of dollars are spent annually in the United States mitigating fire effects on rangeland hydrology and erosion. Rangeland managers and scientists need predictive tools to simulate hydrologic processes dictating post-fire responses, assist mitigation and risk assessments, and predict post-fir...

  9. Climate change and North American rangelands: Assessment of mitigation and adaptation strategies

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Current evidence and projected future climates indicate that climate change is likely to modify the function of and services supplied by rangeland ecosystems. Recent history has demonstrated that climatic variability has a strong influence on both ecological and social components of rangeland system...

  10. Heat dosage and oviposition depth influence egg mortality of two common rangeland grasshopper species

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rangeland fire is a common naturally occurring event and management tool, with the amount and structure of biomass controlling transfer of heat belowground. Temperatures grasshopper eggs are exposed to during rangeland fires are mediated by species specific oviposition traits. This experiment examin...

  11. Evaluation of Utah trefoil collections for rangeland restoration in the southern Great Basin

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Wildfires, weed invasion, and various other land disturbances are common in rangeland ecosystems of the Intermountain Region in the western U.S. Revegetation/restoration may be required on many of these rangelands to improve degraded conditions, speed recovery, and minimize soil erosion. Legumes n...

  12. Application of the Rangeland Hydrology and Erosion Model to Ecological Site Descriptions and Management

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The utility of Ecological Site Descriptions (ESDs) and State-and-Transition Models (STMs) concepts in guiding rangeland management hinges on their ability to accurately describe and predict community dynamics and the associated consequences. For many rangeland ecosystems, plant community dynamics ar...

  13. Fire impacts on rangeland hydrology and erosion in a steep sagebrush dominated landscape

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Wildfire is a major ecological process and management issue on sagebrush dominated rangelands throughout the western United States. Fire in these systems can induce soil water repellency and increase runoff and erosion. Few data are available to quantify fire induced hydrologic impacts on rangelands...

  14. AGWA: The Automated Geospatial Watershed Assessment Tool to Inform Rangeland Management

    EPA Science Inventory

    Do you want a relatively easy to use tool to assess rangeland soil and water conservation practices on rangeland erosion that is specifically designed to use ecological information? New Decision Support Tools (DSTs) that are easy-to-use, incorporate ecological concepts and rangel...

  15. UTILIZATION OF HISTORIC AERIAL PHOTOGRAPHY TO TRACK LONG-TERM VEGETATION RESPONSE TO RANGELAND TREATMENTS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    During the past 100 years, semiarid grasslands in the Southwest have been heavily invaded by shrubs. To combat shrub invasion, a variety of rangeland remediation treatments have been conducted at the Jornada Experimental Range and the New Mexico State University Chihuahuan Desert Rangeland Research...

  16. Lotus utahensis: southern great basin legume for possible use in rangeland revegetation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rangeland ecosystems in the western USA are increasingly vulnerable to wildland fires, weed invasion, and mismanagement. On many of these rangelands, revegetation/restoration may be required to improve degraded conditions, speed recovery, and minimize soil erosion. Legumes native to the Great Basi...

  17. Does Mesquite Growth and Removal Impact Net Greenhouse Gas Emissions in Southwestern Rangelands?

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The encroachment of velvet mesquite (Prosopis velutina) has resulted in increased N inputs to Southwestern rangeland soils. Because woody plant proliferation threatens the sustainability of livestock grazing, however, control of mesquite has been advocated as a means to increase rangeland forage pro...

  18. The 'range problem' after a century of rangeland science: New research themes for altered landscapes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The rangeland science profession in the United States has its roots in the widespread overgrazing and concurrent severe droughts of the late 19th Century. These drivers contributed to rangeland resource degradation especially in the American Southwest—what E. O. Wooton (1908) called "The Range Probl...

  19. Pilot Study for an Assessment of Vegetation Structure for Steppe Rangelands of Central Anatolia

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In the last fifty years, rangelands in the Central Anatolian Region of Turkey have been converted to cropping lands, which has negatively accelerated vegetation change, resulting in overgrazing, poor condition and productivity. In these steppe rangelands, to develop a rational basis for making resto...

  20. Development of an operational UAV / remote sensing capability for rangeland management

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rangeland comprises approximately 70% of the Earth’s land surface area. Much of this vast space is in very remote areas with difficult access. Unmanned Aerial Vehicles (UAVs) have great potential for rangeland management applications. UAVs have several advantages over satellites and piloted aircr...

  1. Rangeland management strategies for adapting to climatic variability: Enhancing the positive and mitigating the negative effects

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rangeland management strategies for adapting to climatic variability are needed to reduce enterprise risk, increase resilience of rangeland/grassland ecosystems and deliver sustainable provision of ecosystem goods (e.g., livestock production) and services (e.g., wildlife habitat) from western North ...

  2. Parameterization of the GPFARM-Range model for simulating rangeland productivity

    Technology Transfer Automated Retrieval System (TEKTRAN)

    One of the major limitations to rangeland model usage is the lack of parameter values appropriate for reliable simulations at different locations and times. In this chapter we seek to show how the GPFARM-Range, a rangeland model, which has been previously parameterized, tested and validated for the ...

  3. Techniques for Assessing the Environmental Outcomes of Conservation Practices Applied to Rangeland Watersheds

    EPA Science Inventory

    Grazing lands are the most dominant land cover type in the United States, with approximately 311.7 Mha being defined as rangelands (Mitchell 2000). Approximately 53% (166.2 Mha) of the nation’s rangelands (USDA 2009) are owned and managed by the private sector, while approximat...

  4. Fire effects on rangeland hydrology and erosion in a steep sagebrush-dominated landscape

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Post-fire runoff and erosion from wildlands has been well researched, but few studies have researched the degree of control exerted by fire on rangeland hydrology and erosion processes. Furthermore, the spatial continuity and temporal persistence of wildfire impacts on rangeland hydrology and erosi...

  5. Forage Production on Dry Rangelands of Binary Grass-Legume Mixtures at Four Plant Densities

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Forage production on Western US rangelands can be increased with the right combination of plants. Our objective was to demonstrate the relative forage production advantage of including a legume on dry rangelands. A falcata and rhizomatous alfalfa (medicago sativa L.), alti wildrye [Leymus andustus...

  6. Using the best available data: integrating field data and remote sensing imagery to monitor rangelands

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Monitoring of rangelands poses significant challenges to land managers due to broad extent and many uses of rangelands. The Bureau of Land Management’s (BLM) Assessment, Inventory, and Monitoring (AIM) program seeks to efficiently collect standard, quantitative monitoring data which is collected onc...

  7. Collection and Domestication of Rangeland Plant Species with Emphasis on Mongolia and China

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Changing economic and social conditions are threatening plant diversity on rangelands in Mongolia and China. Teams of collaborating scientists from the U.S.A., Mongolia, and China collected seed of rangeland plant species in Mongolia and Inner Mongolia, China, to preserve plant biodiversity from th...

  8. Techniques for assessing the environmental outcomes of conservation practices applied to rangeland watersheds

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Grazing lands are the most dominate land cover type in the United States with approximately 311.7 Mha being defined as rangelands. Approximately 53% of the Nation’s rangelands are owned and managed by the private sector while the Federal government manages approximately 43% of the Nation’s rangelan...

  9. TGS pipeline primed for Argentine growth, CEO says

    SciTech Connect

    Share, J.

    1997-03-01

    Nowhere in Latin America has the privatization process been more aggressively pursued than in Argentina where President Carlos Menem has successfully turned over the bulk of state companies to the private sector. In the energy sector, that meant the divestiture in 1992 of Gas del Estado, the state-owned integrated gas transportation and distribution company. It was split in two transportation companies: Transportadora de Gas del Sur (TGS) and Transportadora de Gas del Norte (TGN), and eight distribution companies. TGS is the largest transporter of natural gas in Argentina, delivering more than 60 percent of that nation`s total gas consumption with a capacity of 1.9 Bcf/d. This is the second in a series of Pipeline and Gas Journal special reports that discuss the evolving strategies of the natural gas industry as it continues to restructure amid deregulation. The article focuses on TGS, the Argentine pipeline system in which Enron Corp. is a key participant.

  10. Tectonics of the Argentine and Chilean Andes: An introduction

    NASA Astrophysics Data System (ADS)

    Folguera, Andrés; Alvarado, Patricia; Arriagada, César; Ramos, Victor A.

    2015-12-01

    This Special Issue gathers a series of contributions derived from presentations at the 19° Congreso Geológico Argentino held in Córdoba in 2-6 June 2014. Specific subjects cover a wide variety of topics and regions of the Argentine and Chilean Andes, varying from sedimentological analyses and U/Pb dating of detrital zircons in different rocks to determine source areas for different times and regions along the southern Andes; satellite gravity data for monitoring earthquakes at the subduction zone to understand their complex rupture structure; fission track data from the Andes to the foreland region; use of seismic tomographies and conventional seismic reflection data for analyzing crustal structure; to paleomagnetic data and structural and morphological analyses (Fig. 1).

  11. Colorado Basin Structure and Rifting, Argentine passive margin

    NASA Astrophysics Data System (ADS)

    Autin, Julia; Scheck-Wenderoth, Magdalena; Loegering, Markus; Anka, Zahie; Vallejo, Eduardo; Rodriguez, Jorge; Marchal, Denis; Reichert, Christian; di Primio, Rolando

    2010-05-01

    The Argentine margin presents a strong segmentation with considerable strike-slip movements along the fracture zones. We focus on the volcanic segment (between the Salado and Colorado transfer zones), which is characterized by seaward dipping reflectors (SDR) all along the ocean-continent transition [e.g. Franke et al., 2006; Gladczenko et al., 1997; Hinz et al., 1999]. The segment is structured by E-W trending basins, which differs from the South African margin basins and cannot be explained by classical models of rifting. Thus the study of the relationship between the basins and the Argentine margin itself will allow the understanding of their contemporary development. Moreover the comparison of the conjugate margins suggests a particular evolution of rifting and break-up. We firstly focus on the Colorado Basin, which is thought to be the conjugate of the well studied Orange Basin [Hirsch et al., 2009] at the South African margin [e.g. Franke et al., 2006]. This work presents results of a combined approach using seismic interpretation and structural, isostatic and thermal modelling highlighting the structure of the crust. The seismic interpretation shows two rift-related discordances: one intra syn-rift and the break-up unconformity. The overlying sediments of the sag phase are less deformed (no sedimentary wedges) and accumulated before the generation of oceanic crust. The axis of the Colorado Basin trends E-W in the western part, where the deepest pre-rift series are preserved. In contrast, the basin axis turns to a NW-SE direction in its eastern part, where mainly post-rift sediments accumulated. The most distal part reaches the margin slope and opens into the oceanic basin. The general basin direction is almost orthogonal to the present-day margin trend. The most frequent hypothesis explaining this geometry is that the Colorado Basin is an aborted rift resulting from a previous RRR triple junction [e.g. Franke et al., 2002]. The structural interpretation

  12. Soils of the Galindez Island, Argentine archipelago, Western Antarctica

    NASA Astrophysics Data System (ADS)

    Abakumov, Evgeny; Parnikoza, Ivan

    2015-04-01

    Antarctic Peninsula is a part of Antarctica which is characterized by increased soil diversity, caused by specific of parent materials and diversity of non-vascular and vascular plants. Soils of Galindez Island have been investigated during the 18-th Ukranian Antarctic Expedition 2013/14. This Island situated in Argentine archipelago (coastal part of Antarctic Peninsula). Soils of Galindez Island presented by following types: Leptosols, Lithosols, Histic Lithosols and Leptosols and some Gleyic soils, located in lowlands and coastal parts. An average solum profile thickness is 3-19 cm which result from the small depth of debris's, underplayed by massive crystallic rocks. The permafrost layer is located within the massive rock, but not in coarse friable parent material. The soils with bird influence are widely spread both in coastal and central part of Island. In the coastal parts we can find typical Ornithosols in the penguin rockeries areas. The main aim of our investigation was characterization of soils formed under vegetation, exactly under Deschampsia antarctica Desv. localities. Argentine Islands is the central part of D. antarctica spreading area in region of Antarctic peninsula. Probably, these islands colonized by hairgrass mainly due to ornitogenic activity. So, coastal population appearance related with Larus dominicanus nest areas and feeding activity. Thus, we found typical post ornithogenic soils here. This kind of soils we also observed in population of hairgrass of Galindez mainland where it was connected with the other Antarctic bird - Catharacta maccormicki activity. Thus, the soil diversity and soil geochemistry of the Galindez Island are closely related to the activity of birds. The spatial pattern of soils, their chemistry and organic matter quality is discussed in relation with distribution of bird nesting and feeding activity.

  13. Testing baits to control Argentine ants (Hymenoptera: Formicidae) in vineyards.

    PubMed

    Daane, Kent M; Cooper, Monica L; Sime, Karen R; Nelson, Erik H; Battany, Mark C; Rust, Michael K

    2008-06-01

    Liquid baits were evaluated for control of the Argentine ant, Linepithema humile (Mayr) (Hymenoptera: Formicidae), and associated mealybug and soft scale pests in California vineyards. In 2003, liquid baits with small doses ofimidacloprid, boric acid, or thiamethoxam dissolved in 25% sucrose water resulted in lower ant and mealybug densities and fruit damage, compared with an untreated control. Similar treatments in a soft scale-infested vineyard showed only a reduction of ant density and fruit infestation in only the boric acid and thiamethoxam treatments. In 2004, commercial and noncommercial formulations of liquid baits reduced ant densities in three separate trials, but they had inconsistent effects on mealybug densities and fruit infestation; granular protein bait had no effect. Using large plots and commercial application methodologies, liquid bait deployed in June resulted in lower ant density and fruit infestation, but it had no effect on mealybug density. Across all trials, liquid bait treatments resulted in lower ant density (12 of 14 trials) and fruit damage (11 of 14 sites), presenting the first report of liquid baits applied using commercial methodologies that resulted in a reduction of ants and their associated hemipteran crop damage. For commercialization of liquid baits, we showed that any of the tested insecticides can suppress Argentine ants when properly delivered in the crop system. For imidacloprid, bait dispensers must be protected from sunlight to reduce photodegradation. Results suggest that incomplete ant suppression can suppress mealybug densities. However, after ant populations are suppressed, there may be a longer period before hemipteran populations are effectively suppressed. Therefore, liquid baits should be considered part of a multiseason program rather than a direct, in-season control of hemipteran pest populations. PMID:18613568

  14. Establishment of the Geoglam Rangelands Acivity and Progress

    NASA Astrophysics Data System (ADS)

    Youngentob, K. N.; Held, A. A.; Grundy, M.; Donohue, R. J.

    2014-12-01

    With global population predicted to reach around 9 billion by 2050 and the area of arable land per person declining, there is increased focus on the need to increase food production. As part of a systematic response to that need, improved monitoring of global food production has been identified by the G20 as a priority. The Global Agricultural Monitoring initiative has been established under the Group on Earth Observations (known as GEOGLAM) as a response to this need, with initial focus on the four main food crops of the world and the major exporting regions. However, it is not only the world's croplands that will come under pressure to further increase their productivity and production. Global rangelands, scrublands and pasturelands must become more productive in producing grassland plant biomass and increased animal protein production, to supply an ever-growing global demand for essential animal protein. An essential complementary focus is needed on the sustainability of these systems to both ensure sustained productivity and to maintain the broader range of ecosystem services providing out of these large global lands. Termed "GEOGLAM Rangelands and Pasture Productivity (RAPP)", this new GEO initiative will provide the global community with the means to monitor the world's rangelands and pasture lands on a routine basis, and the capacity to produce animal protein in real-time, at global, regional and national levels. The primary scope of RAPP will be to monitor aboveground biomass and the condition of land cover for those lands and ecosystems that are integral to producing animal protein on a 'free-range', open-field basis, and their sustainable management. Using available national animal herd statistics, aims to include global and regional population information on beef cattle, goats, sheep, camels, pork, dairy cattle, wild and managed buffalo and deer. This paper will provide a broad overview of the status of implementation of the RAPP monitoring system, and

  15. Rangeland degradation assessment: a new strategy based on the ecological knowledge of indigenous pastoralists

    NASA Astrophysics Data System (ADS)

    Behmanesh, Bahareh; Barani, Hossein; Abedi Sarvestani, Ahmad; Shahraki, Mohammad Reza; Sharafatmandrad, Mohsen

    2016-04-01

    In a changing world, the prevalence of land degradation is becoming a serious problem, especially in countries with arid and semi-arid rangelands. There are many techniques to assess rangeland degradation that rely on scientific knowledge but ignore indigenous people. Indigenous people have accumulated precious knowledge about land management through generations of experience. Therefore, a study was conducted to find out how indigenous people assess rangeland degradation and how their ecological knowledge can be used for rangeland degradation assessment. Interviews were conducted with the pastoralists of two sites (Dasht and Mirza Baylu), where part of both areas is located in Golestan National Park (north-eastern Iran). A structured questionnaire was designed based on 17 indicators taken from literature and also primary discussions with pastoralists in order to evaluate land degradation. A qualitative Likert five-point scale was used for scoring rangeland degradation indicators. The results revealed that pastoralists pay more attention to edaphic indicators than to vegetative and other indicators. There were significant differences between the inside and outside of the park in terms of rangeland degradation indicators for both sites. The results show that the rangelands outside of the park in both sites were degraded compared to those inside of the park, especially in the areas close to villages. It can be concluded that pastoralists have a wealth of knowledge about the vegetation and grazing animal habits that can be used in rangeland degradation assessment. It is therefore necessary to document their ecological indigenous knowledge and involve them in the process of rangeland-degradation assessment.

  16. The GEOGLAM Rangelands and Pasture Productivity Activity: Recent Progress and Future Directions

    NASA Astrophysics Data System (ADS)

    Guerschman, J. P.; Held, A. A.; Donohue, R. J.; Renzullo, L. J.; Sims, N.; Kerblat, F.; Grundy, M.

    2015-12-01

    Rangelands and pastures cover about a third of the world's land area and support livestock production which represents ~40% of global agricultural gross domestic product. The global consumption of animal protein shows a clear increasing trend, driven by both total population and per capita income increases, putting a growing pressure on the sustainability of grazing lands worldwide. Despite their relevance, rangelands have received less attention than croplands regarding global monitoring of the resource productivity and condition. The Rangelands and Pasture Productivity (RaPP) activity is a component within the Global Agricultural Monitoring initiative established under the Group on Earth Observations (GEOGLAM) in 2013. GEOGLAM RaPP is aimed at providing the global community with the means to monitor the world's rangelands and pastures on a routine basis, and the capacity to produce animal protein in real-time, at global, regional and national levels. Since its launch two years ago GEOGLAM RAPP has made progress in the four implementation elements. These include: 1- the establishment of community of practice; 2- the development of a global monitoring system for rangeland condition; 3- the establishment of pilot sites in main rangeland systems for satellite data products validation and model testing; and 4- integration with livestock production models. Three international workshops have been held building the community of practice. A prototype monitoring system that provides global visualisations and querying capability of vegetation cover data and anomalies has been established. Pilot sites, mostly in areas with long records of field measurements of rangeland condition and productivity have been proposed for nine countries. The link to global livestock models, including physical and economic components, have been established. Future challenges for GEOGLAM RaPP have also been identified and include: better representation of the areas occupied by rangelands

  17. The crustal structure of the southern Argentine margin

    NASA Astrophysics Data System (ADS)

    Becker, Katharina; Franke, Dieter; Schnabel, Michael; Schreckenberger, Bernd; Heyde, Ingo; Krawczyk, Charlotte M.

    2012-06-01

    Multichannel reflection seismic profiles, combined with gravimetric and magnetic data provide insight into the crustal structure of the southernmost Argentine margin, at the transition from a rifted to a transform margin and outline the extent of the North Falkland Graben. Based on these data, we establish a regional stratigraphic model for the post-rift sediments, comprising six marker horizons with a new formation in the Barremian/Lower Cretaceous. Our observations support that a N-S trending subsidiary branch of the North Falkland Graben continues along the continental shelf and slope to the Argentine basin. During the rift phase, a wide shelf area was affected by the E-W extension, subsequently forming the North Falkland Graben and the subsidiary branch along which finally breakup occurred. We propose the division of the margin in two segments: a N-S trending rifted margin and an E-W trending transform margin. This is further underpinned by crustal scale gravity modelling. Three different tectono-dynamic processes shaped the study area. (1) The Triassic/Early Jurassic extensional phase resulting in the formation of the North Falkland Graben and additional narrower rift grabens ended synchronously with the breakup of the South Atlantic in the early Valanginian. (2) Extensional phase related to the opening of the South Atlantic. (3) The transform margin was active in the study area from about Hauterivian times and activity lasted until late Cretaceous/early Cenozoic. Both, the rifted margin and the transform margin are magma-poor. Very limited structures may have a volcanic origin but are suggested to be post-rift. The oceanic crust was found to be unusually thin, indicating a deficit in magma supply during formation. These findings in combination with the proposed breakup age in the early Valanginian that considerably predates the formation of the Paraná-Etendeka continental flood basalt provinces in Brazil and Namibia question the influence of the Tristan da

  18. The value of milk in rangelands in Mandera County, Kenya

    NASA Astrophysics Data System (ADS)

    Ngugi, Keziah; Ertsen, Maurits

    2015-04-01

    Lack of water over expansive regions in Greater Horn of Africa created the rangelands and rangelands created pastoralism. Pastoralism involve keeping of large livestock herds and movement in search of resources, mainly water, pasture, medicine and wild foods. Several studies have been done in the last century and findings pointed at pastoralism being primitive and unsustainable. It has been predicted it would die in the last century but in the rangelands, pastoralism lives on and it is resilient. This study is based in Mandera, a pastoralism county in Kenya that neighbors Ethiopia to the North and Somalia to the East. The study sought to investigate contribution of milk to pastoralism resilience. Interviews were conducted in the field among the pastoralists, women groups, transporters, traders, government officials and consumers of milk. These information was corroborated with actual field investigations in the expansive rangelands of Mandera County. Pastoralists rarely slaughter or sell their livestock even when the animals waste away during droughts. This is because they have been through such cycles before and observed livestock make tremendous recovery when the right conditions were restored. Rangelands lack infrastructure, there are no roads, schools, telephone or hospitals. Pastoralists diet is comprised of rice, wheat and milk. It was established milk was the main source of income among pastoralists in Mandera County. From milk, the pastoralists make income that is used to purchase the other foodstuffs. Milk is available on daily basis in large quantities owing to the large number of livestock. Unfortunately, every pastoralist household produce copious amounts of milk, thus no local demand and transport infrastructure is nonexistent, making sale of milk a near impossible task. The findings showed the pastoralists have established unique routes through which milk reach the markets in urban centers where demand is high. Urbanization sustain pastoralism. These

  19. Comparison of LANDSAT-2 and field spectrometer reflectance signatures of south Texas rangeland plant communities

    NASA Technical Reports Server (NTRS)

    Richardson, A. J.; Escobar, D. E.; Gausman, H. W.; Everitt, J. H. (Principal Investigator)

    1982-01-01

    The accuracy was assessed for an atmospheric correction method that depends on clear water bodies to infer solar and atmospheric parameters for radiative transfer equations by measuring the reflectance signature of four prominent south Texas rangeland plants with the LANDSAT satellite multispectral scanner (MSS) and a ground based spectroradiometer. The rangeland plant reflectances produced by the two sensors were correlated with no significant deviation of the slope from unity or of the intercept from zero. These results indicated that the atmospheric correction produced LANDSAT MSS estimates of rangeland plant reflectances that are as accurate as the ground based spectroradiometer.

  20. Recirculated and Energy Recovered Linacs

    SciTech Connect

    Geoffrey Krafft

    2003-05-01

    Linacs that are recirculated share many characteristics with ordinary linacs, including the ability to accelerate electron beams from an injector to high energy with relatively little (normalized) emittance growth and the ability to deliver ultrashort bunch duration pulses to users. When such linacs are energy recovered, the additional possibility of accelerating very high average beam current arises. Because this combination of beam properties is not possible from either a conventional linac, or from storage rings where emittance and pulse length are set by the equilibrium between radiation damping and quantum excitation of oscillations about the closed orbit, energy recovered linacs are being considered for an increasing variety of applications. These possibilities extend from high power free-electron lasers and recirculated linac light sources, to electron coolers for high energy colliders or actual electron-ion colliding- beam machines based on an energy recovered linac for the electrons.

  1. Argentine ant trail pheromone disruption is mediated by trail concentration.

    PubMed

    Suckling, David Maxwell; Stringer, Lloyd D; Corn, Joshua E

    2011-10-01

    Argentine ant trail pheromone disruption, using continuous release of the trail pheromone compound (Z)-9-hexadecanal, reduces the incidence of trails and foraging rates of field populations. However, little is known about the concentrations of pheromone required for successful disruption. We hypothesized that higher pheromone quantities would be necessary to disrupt larger ant populations. To test this, we laid a 30-cm long base trail of (Z)-9-hexadecanal on a glass surface at low and high rates (1 and 100 pg/cm) (Trail 1), and laid a second, shorter trail (Trail 2, 10 cm long, located 1.5 cm upwind) near the middle of Trail 1 at six rates (1, 10, 100, 1,000, 10,000, and 100,000 pg/cm). We then recorded and digitized movements of individual ants following Trail 1, and derived a regression statistic, r (2), as an index of trail integrity, and also recorded arrival success at the other end of the trail (30 cm) near a food supply. Disruption of trails required 100 fold more pheromone upwind, independent of base-trail concentration. This implies that in the field, trail disruption is likely to be less successful against high ant-trail densities (greater concentration of trail pheromone), and more successful against newly formed or weak trails, as could be expected along invasion fronts. PMID:21964852

  2. Chemical signals associated with life inhibit necrophoresis in Argentine ants.

    PubMed

    Choe, Dong-Hwan; Millar, Jocelyn G; Rust, Michael K

    2009-05-19

    One of the most conspicuous and stereotyped activities of social insects such as ants and honey bees is necrophoresis, the removal of dead colony members from the nest. Previous researchers suggested that decomposition products such as fatty acids trigger necrophoric behavior by ant workers. However, fatty acids elicit both foraging and necrophoric responses, depending on the current nest activities (e.g., feeding or nest maintenance). Furthermore, workers often carry even freshly killed workers (dead for <1 h) to refuse piles before significant decomposition has a chance to occur. Here, we show that the cuticular chemistry of Argentine ant workers, Linepithema humile, undergoes rapid changes after death. When the workers are alive or freshly killed, relatively large amounts of 2 characteristic ant-produced compounds, dolichodial and iridomyrmecin, are present on the ants' cuticle. However, these compounds disappear from the cuticle within about 1 h after death. We demonstrate how this phenomenon supports an alternative mechanism of ant necrophoresis in which the precise recognition and rapid removal of dead nestmates are elicited by the disappearance of these chemical signals associated with life. PMID:19416815

  3. [Distribution of Lutzomyia longipalpis in the Argentine Mesopotamia, 2010].

    PubMed

    Salomon, Oscar D; Fernandez, Maria S; Santini, María S; Saavedra, Silvina; Montiel, Natalia; Ramos, Marina A; Rosa, Juan R; Szelag, Enrique A; Martinez, Mariela F

    2011-01-01

    The first case of visceral leishmaniasis (VL) in Argentina was reported in 2006 in Posadas, Misiones. During the summer 2008-2009 Lutzomyia longipalpis, the VL vector, and canine VL cases were already spread along the province of Corrientes. In order to know the distribution of VL risk, systematic captures of the vector were performed between February and March 2010, in 18 areas of the provinces of Entre Ríos and Corrientes, and the city of Puerto Iguazú, Misiones, with a total of 313 traps/night. We confirmed the presence of Lu. longipalpis, for the first time in Chajarí (Entre Ríos), Alvear, La Cruz, Curuzú Cuatiá and Bella Vista (Corrientes), and Puerto Iguazú (Misiones). In Santo Tome and Monte Caseros (Corrientes), where the vector had been previously reported, traps with more samples were obtained with 830 and 126 Lu. Longipalpis trap/site/night respectively. These results show that the vector of urban VL continues spreading in the Argentine territory. Simultaneously, the spread of the parasite and the resulting human VL cases are associated with the dispersion of reservoirs, infected dogs, with or without clinical symptoms or signs, due to human transit. PMID:21296716

  4. Monitoring of erythemal irradiance in the Argentine ultraviolet network

    NASA Astrophysics Data System (ADS)

    Cede, Alexander; Luccini, Eduardo; Nuñez, Liliana; Piacentini, Rubén D.; Blumthaler, Mario

    2002-07-01

    The Ultraviolet (UV) Monitoring Network of the Argentine Servicio Meteorológico Nacional (National Weather Service) consists at present of nine stations from 22° to 64° latitude south equipped with biometers, broadband instruments that measure the erythemal irradiance. After a complete calibration of the instruments and reprocessing of the database a preliminary climatology of erythemal irradiance and erythemal exposure was built by analyzing the data of the first 2-4 years for each station. The influence of the measurement interval on the UV Index is quantified. A tropical high-altitude station in the Andean Altiplano reaches top UV Index values of 20 and daily doses of 10.6 kJ/m2, among the highest UV levels worldwide. Characteristic UV lndex and erythemal exposure in the central, most populated areas of Argentina are similar to those in other Southern Hemisphere stations and are higher than in comparable latitude regions of the Northern Hemisphere. The southern stations in the UV network are often affected by the Antarctic ozone hole. By comparing clear-sky irradiance measurements with aerosol-free radiative transfer calculations using the Total Ozone Mapping Spectrometer surface albedo climatology, typical attenuations from 2 to 15% due to aerosols were determined, reaching maxima of 30% at urban locations. On the other hand, increases of ~3-6% due to higher surface albedo were obtained for snow-free conditions, and increases up to 15% were obtained for snow-covered terrain.

  5. Antibiotic sensitivity of an Argentine strain collection of Moraxella bovis.

    PubMed

    Zielinski, G; Piscitelli, H; Perez-Monti, H; Stobbs, L A

    2000-01-01

    The antimicrobial susceptibility of 88 isolates of Moraxella bovis of Argentine origin was evaluated for 12 antimicrobials by broth microdilution procedures. The isolates had a minimum inhibitory concentration (MIC90) of < or = 0.06 microg/mL to enrofloxacin; < or = 0.12 microg/mL to ceftiofur; < or = 0.25 microg/mL to ampicillin; < or = 0.5 microg/mL to florfenicol and gentamicin; < or = 1.0 microg/mL to tilmicosin, erythromycin, and oxytetracycline; < or = 4.0 microg/mL to tylosin; < or = 8.0 microg/mL to spectinomycin; < or = 0.25/4.75 microg/mL to trimethoprim/sulfamethoxazole; and > or = 32 microg/mL to lincomycin. Modal MIC values for these antimicrobials were as follows: enrofloxacin, 0.03 microg/mL; ceftiofur, 0.06 pg/mL; ampicillin, 0.25 microg/mL; florfenicol, gentamicin, erythromycin, and oxytetracycline, 0.5 microg/mL; tilmicosin, 1.0 microg/mL; tylosin and spectinomycin, 4.0 microg/mL; lincomycin and erythromycin, 16 microg/mL; and trimethoprim/ sulfamethoxazole, < or = 0.25/4.75 microg/mL. These data show that all antimicrobials except lincomycin have MICs suggestive of sensitivity in vitro, though confirmation of clinical efficacy can only be properly assessed based on pharmacologic and/or clinical data to support the MIC values. PMID:19757583

  6. Recovering Zinc From Discarded Tires

    NASA Technical Reports Server (NTRS)

    Du Fresne, E. R.

    1984-01-01

    Zinc sulfate monohydrate sold at profit. Shredded tire material steeped in three sulfuric acid baths to extract zinc. Final product removed by evaporating part of solution until product crystallizes out. Recovered as zinc sulfate monohydrate and sold as fertilizer or for general use.

  7. PROCESS OF RECOVERING ALKALI METALS

    DOEpatents

    Wolkoff, J.

    1961-08-15

    A process is described of recovering alkali metal vapor by sorption on activated alumina, activated carbon, dehydrated zeolite, activated magnesia, or Fuller's earth preheated above the vaporization temperature of the alkali metal and subsequent desorption by heating the solvent under vacuum. (AEC)

  8. Multiscale sagebrush rangeland habitat modeling in southwest Wyoming

    USGS Publications Warehouse

    Homer, Collin G.; Aldridge, Cameron L.; Meyer, Debra K.; Coan, Michael J.; Bowen, Zachary H.

    2009-01-01

    Sagebrush-steppe ecosystems in North America have experienced dramatic elimination and degradation since European settlement. As a result, sagebrush-steppe dependent species have experienced drastic range contractions and population declines. Coordinated ecosystem-wide research, integrated with monitoring and management activities, would improve the ability to maintain existing sagebrush habitats. However, current data only identify resource availability locally, with rigorous spatial tools and models that accurately model and map sagebrush habitats over large areas still unavailable. Here we report on an effort to produce a rigorous large-area sagebrush-habitat classification and inventory with statistically validated products and estimates of precision in the State of Wyoming. This research employs a combination of significant new tools, including (1) modeling sagebrush rangeland as a series of independent continuous field components that can be combined and customized by any user at multiple spatial scales; (2) collecting ground-measured plot data on 2.4-meter imagery in the same season the satellite imagery is acquired; (3) effective modeling of ground-measured data on 2.4-meter imagery to maximize subsequent extrapolation; (4) acquiring multiple seasons (spring, summer, and fall) of an additional two spatial scales of imagery (30 meter and 56 meter) for optimal large-area modeling; (5) using regression tree classification technology that optimizes data mining of multiple image dates, ratios, and bands with ancillary data to extrapolate ground training data to coarser resolution sensors; and (6) employing rigorous accuracy assessment of model predictions to enable users to understand the inherent uncertainties. First-phase results modeled eight rangeland components (four primary targets and four secondary targets) as continuous field predictions. The primary targets included percent bare ground, percent herbaceousness, percent shrub, and percent litter. The

  9. Collaborative adaptive landscape management (CALM) in rangelands: Discussion of general principles

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The management of rangeland landscapes involves broad spatial extents, mixed land ownership, and multiple resource objectives. Management outcomes depend on biophysical heterogeneity, highly variable weather conditions, land use legacies, and spatial processes such as wildlife movement, hydrological...

  10. SOIL MICROARTHROPODS AS INDICATORS OF EXPOSURE TO ENVIRONMENTAL STRESS IN CHIHUAHUAN DESERT RANGELANDS

    EPA Science Inventory

    We studied soil microarthropod communities along livestock grazing disturbance gradients, inside and outside grazing exclosures, and on areas subjected to restoration efforts (herbicide and bulldozing) in order to test the suitability of mites as indicators of rangeland soil qual...

  11. How can science general, yet specific: The conundrum of rangeland science in the 21st Century

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Traditional approaches to understanding, predicting, and managing rangelands based on assumptions about homogeneity in space and stationarity in time of environmental drivers are expected to be insufficient in the future. Range scientists, ecologists, and global system scientists use approaches that...

  12. Overgrazing- How far are we from passing the tipping point of turning our rangelands into desert?

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Ecological science, particularly with regard to Mongolian rangelands, is not able to estimate when a tipping point will be passed. Nonetheless, it does provide a framework for responding to the threat of desertification tipping points. ...

  13. Are we "missing the boat" on preventing the spread of invasive plants in rangelands?

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Invasive plants are negatively impacting the ecological and economic production of rangelands by reducing resource productivity, decreasing biodiversity, displacing native vegetation, and altering ecosystem processes and functions. However, despite these well known negative impacts, once invasive p...

  14. Success of seeding native compared with introduced perennial vegetation for revegetating medusahead-invaded sagebrush rangeland

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Millions of hectares of Wyoming big sagebrush (Artemisia tridentata Nutt. ssp. wyomingensis Beetle &Young) rangeland have been invaded by medusahead (Taeniatherum caput-medusae [L.] Nevski), an exotic annual grass that degrades wildlife habitat, reduces forage production, and decreases biodiversity....

  15. Feeding strategy of juvenile (age-0+ year) Argentine hake Merluccius hubbsi in the Patagonian nursery ground.

    PubMed

    Temperoni, B; Viñas, M D; Buratti, C C

    2013-11-01

    Age-0+ year juvenile Argentine hake Merluccius hubbsi (60-150 mm total length, L(T)) from San Jorge Gulf, north Patagonian shelf region of the Argentine Sea, had an almost exclusively pelagic diet dominated by the hyperiid amphipod Themisto gaudichaudii and the euphausiid Euphausia lucens. This suggested that final settlement and permanent demersal habitat utilization might not, as previously reported, occur at earlier sizes (c. 20 mm L(T)). Their feeding strategy involves specialization at a population level towards both the main pelagic prey, indicating a narrow trophic niche. Novel data are provided which contribute to the growing body of information in relation to the age-0+ year transitional stage in demersal fishes and particularly to M. hubbsi recruitment in the Argentine Sea. PMID:24580669

  16. Biotic and abiotic controls of argentine ant invasion success at local and landscape scales

    USGS Publications Warehouse

    Menke, S.B.; Fisher, R.N.; Jetz, W.; Holway, D.A.

    2007-01-01

    Although the ecological success of introduced species hinges on biotic interactions and physical conditions, few experimental studies - especially on animals - have simultaneously investigated the relative importance of both types of factors. The lack of such research may stem from the common assumption that native and introduced species exhibit similar environmental tolerances. Here we combine experimental and spatial modeling approaches (1) to determine the relative importance of biotic and abiotic controls of Argentine ant (Linepithema humile) invasion success, (2) to examine how the importance of these factors changes with spatial scale in southern California (USA), and (3) to assess how Argentine ants differ from native ants in their environmental tolerances. A factorial field experiment that combined native ant removal with irrigation revealed that Argentine ants failed to invade any dry plots (even those lacking native ants) but readily invaded all moist plots. Native ants slowed the spread of Argentine ants into irrigated plots but did not prevent invasion. In areas without Argentine ants, native ant species showed variable responses to irrigation. At the landscape scale, Argentine ant occurrence was positively correlated with minimum winter temperature (but not precipitation), whereas native ant diversity increased with precipitation and was negatively correlated with minimum winter temperature. These results are of interest for several reasons. First, they demonstrate that fine-scale differences in the physical environment can eclipse biotic resistance from native competitors in determining community susceptibility to invasion. Second, our results illustrate surprising complexities with respect to how the abiotic factors limiting invasion can change with spatial scale, and third, how native and invasive species can differ in their responses to the physical environment. Idiosyncratic and scale-dependent processes complicate attempts to forecast where

  17. Combined effect of hemipteran control and liquid bait on Argentine ant populations.

    PubMed

    Brightwell, R J; Bambara, S B; Silverman, J

    2010-10-01

    The invasive Argentine ant, Linepithema humile (Mayr), has become a worldwide problem capable of inflicting significant ecological and economic injury on urban, agricultural, and natural environments. The mobility of this pest ant has long been noted, rapidly moving nests to new food resources and then away as resources are depleted. This ant, like many pest ant species, has a special affinity for honeydew excreted by phloem-feeding Hemiptera. We investigated the effect of various hemipteran control strategies on terrapin scale densities and measured their indirect effect on local Argentine ant densities and foraging effort. We then determined whether this indirect treatment strategy improved the performance of an ant bait. We predicted that Argentine ants would move nests away from trees treated for Hemiptera and then move nests back when a liquid bait was offered, followed by a decline in ant numbers due to intake of the toxicant. A horticultural oil spray and soil application of the systemic insecticide, imidacloprid, had no effect on terrapin scale numbers. However, trunk-injected dicrotophos caused a reduction in scale and a decline in local Argentine ant nest density and canopy foraging effort. We also recorded a reduction in local Argentine ant ground foraging when large amounts of liquid bait were applied, and we found no evidence that combining dicrotophos with liquid ant bait performed better than each treatment alone. We suggest that a strategy of combined hemipteran control plus application of liquid ant bait can reduce local Argentine ant densities, when both components of this system are highly efficacious. PMID:21061981

  18. Capability of AVHRR data in discriminating rangeland cover mixtures

    USGS Publications Warehouse

    Senay, Gabriel B.; Elliott, R.L.

    2002-01-01

    A combination of high temporal resolution Advanced Very High Resolution Radiometer (AVHRR) data and high spatial information Map Information Analysis and Display System (MIADS) landuse/landcover data from the United States Department of Agriculture-Natural Resources Conservation Service (USDA-NRCS) were used to investigate the feasibility of using the combined dataset for regional evapotranspiration (ET) studies. It was shown that the biweekly maximum Normalized Difference Vegetation Index (NDVI) composite AVHRR data were capable of discriminating rangelands with different types of trees and shrubs species. AVHRR data also showed a potential to distinguish canopy cover differences within a mix of similar species. The combination of MIADS data and AVHRR data can be used to study temporal dynamics of various cover types for use in regional ET estimates.

  19. A simple graphical approach to quantitative monitoring of rangelands

    USGS Publications Warehouse

    Riginos, C.; Herrick, J.E.; Sundaresan, S.R.; Farley, C.; Belnap, J.

    2011-01-01

    The article reviews graphical interpretation of the four monitoring methods that can be used to generate a variety of indicators of rangeland ecosystem function. Data for all four of the monitoring methods can be recorded on a single data sheet that is designed to be usable by somebody with minimal literacy. Indicators of plant and ground cover are central to most long-term monitoring systems. Plant and ground-cover data inform managers about forage availability, plant community composition and structure, and risk of runoff and erosion. The spatial arrangement of plants at a site in addition to the percent of the ground that is covered by plants is an important determinant of erosion potential. Vertical vegetation structure can be monitored by capturing data on maximum plant height at each stick location. Plant density method can provide an early indicator of future changes in plant cover, forage, quality, and habitat structure.

  20. Aircraft scatterometer observations of soil moisture on rangeland watersheds

    NASA Technical Reports Server (NTRS)

    Jackson, T. J.; Oneill, P. E.

    1983-01-01

    Extensive studies conducted by several researchers using truck-mounted active microwave sensors have shown the sensitivity of these sensors to soil moisture variations. The logical extension of these results is the evaluation of similar systems at lower resolutions typical of operational systems. Data collected during a series of aircraft flights in 1978 and 1980 over four rangeland watersheds located near Chickasha, Oklahoma, were analyzed in this study. These data included scatterometer measurements made at 1.6 and 4.75 GHz using a NASA aircraft and ground observations of soil moisture for a wide range of moisture conditions. Data were analyzed for consistency and compared to previous truck and aircraft results. Results indicate that the sensor system is capable of providing consistent estimates of soil moisture under the conditions tested.

  1. Potential for Carbon Sequestration using Organic Amendments on Rangeland Soils

    NASA Astrophysics Data System (ADS)

    Ryals, R.; Silver, W. L.

    2009-12-01

    Managed rangelands represent a geographically large land-use footprint and thus have considerable potential to sequester carbon (C) in soil through changes in management practices. Organic amendments are frequently added to agricultural and rangeland soils in an effort to improve fertility and yield, yet little is known about their impact on greenhouse gas dynamics and soil biogeochemical dynamics, especially in rangeland soils. This research aims to explore the effects of organic amendments on soil chemical and physical properties, plant inputs, and soil C and N dynamics in managed rangeland ecosystems. Our research uses field manipulations at two Mediterranean grassland ecosystems replicated within and across bioclimatic zones: the Sierra Foothills Research and Extension Center (SFREC) in Browns Valley, CA and the Nicasio Native Grass Ranch in Nicasio, CA. Both sites are dominated by annual grasses and are moderately grazed by cattle. Three replicate blocks at each site contain 60m x 25m treatment plots (organic amendments and control) with 5m buffer strips. Organic amendments were applied at a level of 14 MgC/ha (equivalent to a 1.27cm surface dressing) at the beginning of the wet season (December 2008). During the wet season (October through June), carbon dioxide (CO2) flux was measured weekly using a LI-8100, while fluxes of methane (CH4) and nitrous oxide (N2O) were measured biweekly using static flux chambers. During the dry season (June through September), fluxes were measured biweekly and monthly, respectively. Soil organic C (SOC) and nitrogen (N) were measured prior to treatment and seven months following treatment at 0-10, 10-30, 30-50, and 50-100 cm depths. Soil moisture and temperature were measured continuously. Changes in oxidative and hydrolytic extracellular enzyme activities are also being explored. After the first year of management, both sites responded similarly to treatments in both trend and magnitude. For example, at SFREC, total soil

  2. Soil degradation in wooded rangelands of southwest Spain

    NASA Astrophysics Data System (ADS)

    Schnabel, S.; Lavado Contador, J. F.; Gómez Gutiérrez, Á.

    2009-04-01

    The paper presents a review on soil degradation studies carried out since 1990 in wooded rangelands in Extremadura. In the semiarid and subhumid parts of the south-western Iberian Peninsula open evergreen woodlands dominated by Quercus species are widespread (dehesas and montados). They are composed of grasslands with a varying degree of tree cover, ranging from treeless to more than 80 individuals per hectare. In some areas shrubs form a third component of the vegetation. Dehesas are subject to a complex exploitation system with agro-silvo-pastoral land use. The dominant soil degradation phenomena include different forms of water erosion and physical and biological degradation. Regarding soil erosion and surface hydrology, research has been carried out at different spatial scales. Sheetwash and overland flow were investigated along hillslopes and in microplots, whereas gully erosion and runoff production were monitored in small experimental catchments. Recently, physical and biological degradation has been studied in a large number of farms, representing the most important types of rangelands in the region of Extremadura. This included a rapid appraisal of degradation features, the determination of soil properties and a study on the distribution and activity of gullies. Soil degradation varies strongly with regard to the natural factors, but also with respect to land use and management. Sheetwash (interrill erosion) is the dominant process on hillslopes, with a mean soil loss rate of 0.63 t ha-1. However rainfall variation and land management, especially livestock density, produce changes in soil cover. With low to moderate livestock densities and during prolonged periods with low rainfall (droughts), the vegetation cover may be strongly reduced, provoking high soil losses, whereas during normal or humid periods interrill erosion is low. Excessive stocking rates may exacerbate sheetwash, producing severe soil degradation, regardless of rainfall conditions. In

  3. State of knowledge about energy development impacts on North American rangelands: An integrative approach.

    PubMed

    Kreuter, Urs P; Iwaasa, Alan D; Theodori, Gene L; Ansley, R James; Jackson, Robert B; Fraser, Lauchlan H; Naeth, M Anne; McGillivray, Susan; Moya, Edmundo Garcia

    2016-09-15

    To reduce dependence on foreign oil reserves, there has been a push in North America to develop alternative domestic energy resources. Relatively undeveloped renewable energy resources include biofuels and wind and solar energy, many of which occur predominantly on rangelands. Rangelands are also key areas for natural gas development from shales and tight sand formations. Accordingly, policies aimed at greater energy independence are likely to affect the delivery of crucial ecosystem services provided by rangelands. Assessing and dealing with the biophysical and socio-economic effects of energy development on rangeland ecosystems require an integrative and systematic approach that is predicated on a broad understanding of diverse issues related to energy development. In this article, we present a road map for developing an integrative assessment of energy development on rangelands in North America. We summarize current knowledge of socio-economic and biophysical aspects of rangeland based energy development, and we identify knowledge gaps and monitoring indicators to fill these knowledge gaps. PMID:27183477

  4. [A century of legislation as regards Italy-Argentine immigration, 1860-1960].

    PubMed

    Olivieri, M

    1987-01-01

    This paper analyzes the changes in Argentine laws regarding migration, mainly in the hundred years since the Argentine Constitution was passed until the 1950s. The different subsequent laws and the debates they caused are related by the author to the political and ideological trends dominating Argentina in that period as to the characteristics and oscillations of the migratory afflux. Further the paper considers Italian laws and migration policies during the same period. The author concludes that after a liberal migration policy in the 19th century, growing legal restrictions and passionate discussion on the role of immigrants followed in this century, particularly between the 2 World Wars. PMID:12269146

  5. Agronomic characterization of the Argentina Indicator Region. [U.S. corn belt and Argentine pampas

    NASA Technical Reports Server (NTRS)

    Hicks, D. R. (Principal Investigator)

    1982-01-01

    An overview of the Argentina indicator region including information on topography, climate, soils and vegetation is presented followed by a regionalization of crop livestock land use. Corn/soybean production and exports as well as agricultural practices are discussed. Similarities and differences in the physical agronomic scene, crop livestock land use and agricultural practices between the U.S. corn belt and the Argentine pampa are considered. The Argentine agricultural economy is described. Crop calendars for the Argentina indicator region, an accompanying description, notes on crop-livestock zones, wheat production, field size, and agricultural problems and practices are included.

  6. Evaluation of Bare Ground on Rangelands using Unmanned Aerial Vehicles

    SciTech Connect

    Robert P. Breckenridge; Maxine Dakins

    2011-01-01

    Attention is currently being given to methods that assess the ecological condition of rangelands throughout the United States. There are a number of different indicators that assess ecological condition of rangelands. Bare Ground is being considered by a number of agencies and resource specialists as a lead indicator that can be evaluated over a broad area. Traditional methods of measuring bare ground rely on field technicians collecting data along a line transect or from a plot. Unmanned aerial vehicles (UAVs) provide an alternative to collecting field data, can monitor a large area in a relative short period of time, and in many cases can enhance safety and time required to collect data. In this study, both fixed wing and helicopter UAVs were used to measure bare ground in a sagebrush steppe ecosystem. The data were collected with digital imagery and read using the image analysis software SamplePoint. The approach was tested over seven different plots and compared against traditional field methods to evaluate accuracy for assessing bare ground. The field plots were located on the Idaho National Laboratory (INL) site west of Idaho Falls, Idaho in locations where there is very little disturbance by humans and the area is grazed only by wildlife. The comparison of fixed-wing and helicopter UAV technology against field estimates shows good agreement for the measurement of bare ground. This study shows that if a high degree of detail and data accuracy is desired, then a helicopter UAV may be a good platform. If the data collection objective is to assess broad-scale landscape level changes, then the collection of imagery with a fixed-wing system is probably more appropriate.

  7. Recovering entanglement by local operations

    SciTech Connect

    D’Arrigo, A.; Lo Franco, R.; Benenti, G.; Paladino, E.; Falci, G.

    2014-11-15

    We investigate the phenomenon of bipartite entanglement revivals under purely local operations in systems subject to local and independent classical noise sources. We explain this apparent paradox in the physical ensemble description of the system state by introducing the concept of “hidden” entanglement, which indicates the amount of entanglement that cannot be exploited due to the lack of classical information on the system. For this reason this part of entanglement can be recovered without the action of non-local operations or back-transfer process. For two noninteracting qubits under a low-frequency stochastic noise, we show that entanglement can be recovered by local pulses only. We also discuss how hidden entanglement may provide new insights about entanglement revivals in non-Markovian dynamics.

  8. Methods of recovering alkali metals

    DOEpatents

    Krumhansl, James L; Rigali, Mark J

    2014-03-04

    Approaches for alkali metal extraction, sequestration and recovery are described. For example, a method of recovering alkali metals includes providing a CST or CST-like (e.g., small pore zeolite) material. The alkali metal species is scavenged from the liquid mixture by the CST or CST-like material. The alkali metal species is extracted from the CST or CST-like material.

  9. Argentine experience in the field of illegal immigration.

    PubMed

    Villar, J M

    1984-01-01

    This article provides a brief history of Argentine policy toward migratory flows from neighboring countries and Europe, and concludes with statistics on the number of foreigners in Argentina in the 1970-80 period. Measures passed during the 1940s and 1950s were aimed at providing amnesty for foreigners who were residing in Argentina without immigrant status. However, the lack of an adequate administrative structure to regulate foreigners at the borders was a drawback for migration authorities and limited the possiblility of applying admission criteria effectively. By 1970, there were 583,000 foreigners from neighboring countries living in Argentina, which represented a 25% increase from 1960. 42% of these migrants were in the metropolitan region of the country, indicative of a shift away from employment in agriculture. Decree No. 87, passed in 1974, represented an extension of a migration policy aimed at granting ample facilities for permanent residence to aliens from contiguous countries and was designed to prevent abuse of clandestine workers by employers. As a result of this measure, 150,000 foreigners were able to settle legally in the country. A 1981 law, yet to be implemented, establishes a new legal framework aimed at fostering immigration and regulating the admission of foreigners. To attain the objective of settling workers in areas of the country considered of prime importance to economic development, the law provides for infrastructural investments and promotional measures in areas such as tax exemption and the granting of credit. The 1980 National Population Census indicated there were 677,000 foreigners from neighboring countries in Argentina. In that year, foreigners comprised 2.4% of the country's population and 3.1% of the inhabitants of the metropolitan region. These figures are indicative of a decline in the growth of immigration, most likely due to the decline in the purchasing power of workers' salaries in the late 1970s. PMID:12339919

  10. DNA Barcoding Identifies Argentine Fishes from Marine and Brackish Waters

    PubMed Central

    Mabragaña, Ezequiel; Díaz de Astarloa, Juan Martín; Hanner, Robert; Zhang, Junbin; González Castro, Mariano

    2011-01-01

    Background DNA barcoding has been advanced as a promising tool to aid species identification and discovery through the use of short, standardized gene targets. Despite extensive taxonomic studies, for a variety of reasons the identification of fishes can be problematic, even for experts. DNA barcoding is proving to be a useful tool in this context. However, its broad application is impeded by the need to construct a comprehensive reference sequence library for all fish species. Here, we make a regional contribution to this grand challenge by calibrating the species discrimination efficiency of barcoding among 125 Argentine fish species, representing nearly one third of the known fauna, and examine the utility of these data to address several key taxonomic uncertainties pertaining to species in this region. Methodology/Principal Findings Specimens were collected and morphologically identified during crusies conducted between 2005 and 2008. The standard BARCODE fragment of COI was amplified and bi-directionally sequenced from 577 specimens (mean of 5 specimens/species), and all specimens and sequence data were archived and interrogated using analytical tools available on the Barcode of Life Data System (BOLD; www.barcodinglife.org). Nearly all species exhibited discrete clusters of closely related haplogroups which permitted the discrimination of 95% of the species (i.e. 119/125) examined while cases of shared haplotypes were detected among just three species-pairs. Notably, barcoding aided the identification of a new species of skate, Dipturus argentinensis, permitted the recognition of Genypterus brasiliensis as a valid species and questions the generic assignment of Paralichthys isosceles. Conclusions/Significance This study constitutes a significant contribution to the global barcode reference sequence library for fishes and demonstrates the utility of barcoding for regional species identification. As an independent assessment of alpha taxonomy, barcodes provide

  11. Recover and purify hydrogen economically

    SciTech Connect

    Mehra, Y.R.

    1987-01-01

    With continued processing of crudes having higher sulfur content and higher carbon-to-hydrogen ratio and stricter environmental regulations requiring lower sulfur content of products such as diesel fuel, the hydrogen demand is expected to grow. Even though a substantial portion of this increased demand will be met by steam reforming of light hydrocarbons and partial oxidation of heavy hydrocarbons, upgrading existing refinery off-gas streams is a viable alternative. Several processes are available for recovering hydrogen from off-gas streams. These processes include cryogenic separation, catalytic purification, pressure swing adsorption and membrane separation. The process selection depends upon many factors, including the desired hydrogen product purity, hydrogen recovery levels, the available pressure drop, pretreatment requirements, the off-gas composition, the impact of impurities remaining in hydrogen product and turndown capability of such a facility. A new selective solvent process which recovers hydrogen from refinery and petrochemical off-gas streams is the subject of this paper. This technology, known as the Mehra Process, was originally developed for recovering hydrocarbons from natural gas streams. However, this technology also offers another alternative to refiners for the recovery of high purity hydrogen from off-gas streams.

  12. Multi-paddock grazing on rangelands: why the perceptual dichotomy between research results and rancher experience?

    PubMed

    Teague, Richard; Provenza, Fred; Kreuter, Urs; Steffens, Tim; Barnes, Matt

    2013-10-15

    Maintaining or enhancing the productive capacity and resilience of rangeland ecosystems is critical for the continued support of people who depend on them for their livelihoods, especially in the face of climatic change. This is also necessary for the continued delivery of ecosystem services derived from rangelands for the broader benefit of societies around the world. Multi-paddock grazing management has been recommended since the mid-20th century as an important tool to adaptively manage rangelands ecosystems to sustain productivity and improve animal management. Moreover, there is much anecdotal evidence from producers that, if applied appropriately, multi-paddock grazing can improve forage and livestock production. By contrast, recent reviews of published rangeland-based grazing systems studies have concluded that, in general, field trials show no superiority of vegetation or animal production in multi-paddock grazing relative to continuous yearlong stocking of single-paddock livestock production systems. Our goal is to provide a framework for rangeland management decisions that support the productivity and resiliency of rangelands and then to identify why different perceptions exist among rangeland managers who have effectively used multi-paddock grazing systems and research scientists who have studied them. First, we discuss the ecology of grazed ecosystems under free-ranging herbivores and under single-paddock fenced conditions. Second, we identify five principles underpinning the adaptive management actions used by successful grazing managers and the ecological, physiological, and behavioral framework they use to achieve desired conservation, production, and financial goals. Third, we examine adaptive management principles needed to successfully manage rangelands subjected to varying environmental conditions. Fourth, we describe the differences between the interpretation of results of grazing systems research reported in the scientific literature and the

  13. Effects of honeydew-producing hemipteran denial on local argentine ant distribution and boric acid bait performance.

    PubMed

    Brightwell, R J; Silverman, J

    2009-06-01

    The Argentine ant is well known for its affinity for honeydew and is often associated with hemipteran outbreaks in agricultural and urban environments. It has been suggested that Argentine ants may be controlled by restricting access to honeydew, thereby forcing the ants to move or by encouraging increased liquid toxicant intake. We tested this possible control strategy by restricting Argentine ant access to the honeydew-producing terrapin scale within the canopy of red maple trees and monitoring ant numbers with pitfall traps and nest counts in the mulch around the tree base. Argentine ant nest numbers fell dramatically in the mulch around ant-excluded trees; however, there was no reduction in Argentine ant numbers caught in pitfalls around trees with or without canopy access. We added 0.5% boric acid bait stations at the base of the red maples and monitored bait consumption. Pitfall and nest counts were not affected by the addition of boric acid, although bait consumption was lower around ant-excluded trees, suggesting that restricting access to honeydew-producing Hemiptera did not enhance bait performance. We attribute this result to the increased distance Argentine ant workers had to trail from nest to bait station when not tending nearby terrapin scale. We suggest an alternative management strategy concentrating direct insecticidal control of Argentine ants around a few host plants infested with honeydew-producing Hemiptera by controlling Hemiptera in nearby host plants. PMID:19610434

  14. Draft genome of the globally widespread and invasive Argentine ant (Linepithema humile).

    PubMed

    Smith, Christopher D; Zimin, Aleksey; Holt, Carson; Abouheif, Ehab; Benton, Richard; Cash, Elizabeth; Croset, Vincent; Currie, Cameron R; Elhaik, Eran; Elsik, Christine G; Fave, Marie-Julie; Fernandes, Vilaiwan; Gadau, Jürgen; Gibson, Joshua D; Graur, Dan; Grubbs, Kirk J; Hagen, Darren E; Helmkampf, Martin; Holley, Jo-Anne; Hu, Hao; Viniegra, Ana Sofia Ibarraran; Johnson, Brian R; Johnson, Reed M; Khila, Abderrahman; Kim, Jay W; Laird, Joseph; Mathis, Kaitlyn A; Moeller, Joseph A; Muñoz-Torres, Monica C; Murphy, Marguerite C; Nakamura, Rin; Nigam, Surabhi; Overson, Rick P; Placek, Jennifer E; Rajakumar, Rajendhran; Reese, Justin T; Robertson, Hugh M; Smith, Chris R; Suarez, Andrew V; Suen, Garret; Suhr, Elissa L; Tao, Shu; Torres, Candice W; van Wilgenburg, Ellen; Viljakainen, Lumi; Walden, Kimberly K O; Wild, Alexander L; Yandell, Mark; Yorke, James A; Tsutsui, Neil D

    2011-04-01

    Ants are some of the most abundant and familiar animals on Earth, and they play vital roles in most terrestrial ecosystems. Although all ants are eusocial, and display a variety of complex and fascinating behaviors, few genomic resources exist for them. Here, we report the draft genome sequence of a particularly widespread and well-studied species, the invasive Argentine ant (Linepithema humile), which was accomplished using a combination of 454 (Roche) and Illumina sequencing and community-based funding rather than federal grant support. Manual annotation of >1,000 genes from a variety of different gene families and functional classes reveals unique features of the Argentine ant's biology, as well as similarities to Apis mellifera and Nasonia vitripennis. Distinctive features of the Argentine ant genome include remarkable expansions of gustatory (116 genes) and odorant receptors (367 genes), an abundance of cytochrome P450 genes (>110), lineage-specific expansions of yellow/major royal jelly proteins and desaturases, and complete CpG DNA methylation and RNAi toolkits. The Argentine ant genome contains fewer immune genes than Drosophila and Tribolium, which may reflect the prominent role played by behavioral and chemical suppression of pathogens. Analysis of the ratio of observed to expected CpG nucleotides for genes in the reproductive development and apoptosis pathways suggests higher levels of methylation than in the genome overall. The resources provided by this genome sequence will offer an abundance of tools for researchers seeking to illuminate the fascinating biology of this emerging model organism. PMID:21282631

  15. Applied Ecology and Control of Imported Fire Ants and Argentine Ants

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The red imported fire ant, Solenopsis invicta Buren, and Argentine ant, Linepithema humile (Mayr), are invasive species that are major pests in urban, natural, and agricultural habitats. The goal of this dissertation was to study aspects the chemical sensitivity, behavior, and ecology of each specie...

  16. Argentine Hydrellia Robineau-Desvoidy (Diptera, Ephydridae): new species and key to identification.

    PubMed

    Rodrigues Júnior, Francisco De Assis; Mathis, Wayne Nielsen; Hauser, Martin

    2015-01-01

    Hydrellia egeriae sp. nov., a new species of Hydrellia from Campana (34 14' 04 S, 58 52' 32 W) and Hurlingham (3435'14 S, 5838'27 W), Buenos Aires province, Argentina is described. A key to the Argentine Hydrellia species is presented. PMID:26249060

  17. Schooling and Governance: Pedagogical Knowledge and Bureaucratic Expertise in the Genesis of the Argentine Educational System

    ERIC Educational Resources Information Center

    Southwell, Myriam

    2013-01-01

    The consolidation of the Argentine Federal Government by the 1870s aimed to modernise local society, establish state institutions and reach political stabilisation. Building a modern schooling system articulated both utopia and bureaucracy by establishing the use of knowledge as an instrument of social intervention, vindicating and legitimising…

  18. Library Networks in Less-Developed Countries: Two Argentine Cases and Some Observations.

    ERIC Educational Resources Information Center

    Tang, Donna Taxco

    As an American Library Association/USIA International Library Fellow in Argentina from March to September 1989, the author worked with the Argentine National Protective Commission for People's Libraries. Included in her assignment was a charge "to assist in the development of a popular libraries network in Patagonia," the southernmost region of…

  19. Perceptions of ranchers about medusahead (Taeniatherum caput-medusae (L.) Nevski) management on sagebrush steppe rangelands.

    PubMed

    Johnson, Dustin D; Davies, Kirk W; Schreder, Peter T; Chamberlain, Anna-Marie

    2011-09-01

    Medusahead (Taeniatherum caput-medusae (L.) Nevski) is an exotic annual grass invading rangelands in the western United States. Medusahead is a serious management concern because it decreases biodiversity, reduces livestock forage production, and degrades the ecological function of rangelands. Despite the obvious importance of ranchers as partners in preventing and managing medusahead in rangelands, little is known about their perceptions and behaviors concerning medusahead management. We present the results of a survey of ranchers operating on sagebrush steppe rangeland in a three-county area in southeast Oregon encompassing over 7.2 million ha. The primary objective of this research was to determine if the presence of medusahead on a ranch influenced its operator's perceptions and behaviors concerning invasive plant control and prevention. Ranchers operating on medusahead-infested rangeland were more likely to indicate increased awareness and concern about medusahead and the potential for its continued expansion. Ranchers operating on rangeland invaded by medusahead were also more likely to indicate use of measures to prevent the spread of medusahead and other invasive plants on rangeland, interest in educational opportunities concerning invasive annual grass management, and plans for controlling invasive annual grasses in the future. This study revealed an alarming trend in which individuals are less likely to implement important prevention measures and participate in education opportunities to improve their knowledge of invasive plants until they directly experience the negative consequences of invasion. Information campaigns on invasive plants and their impacts may rectify this problem; however, appropriate delivery methods are critical for success. Web- or computer-based invasive plant information and tools were largely unpopular among ranchers, whereas traditional forms of information delivery including brochures/pamphlets and face-to-face interaction were

  20. Introduced and invasive species in novel rangeland ecosystems: friends or foes?

    USGS Publications Warehouse

    Belnap, Jayne; Ludwig, John A.; Wilcox, Bradford P.; Betancourt, Julio L.; Dean, W. Richard J.; Hoffmann, Benjamin D.; Milton, Sue J.

    2012-01-01

    Globally, new combinations of introduced and native plant and animal species have changed rangelands into novel ecosystems. Whereas many rangeland stakeholders (people who use or have an interest in rangelands) view intentional species introductions to improve forage and control erosion as beneficial, others focus on unintended costs, such as increased fire risk, loss of rangeland biodiversity, and threats to conservation efforts, specifically in nature reserves and parks. These conflicting views challenge all rangeland stakeholders, especially those making decisions on how best to manage novel ecosystems. To formulate a conceptual framework for decision making, we examined a wide range of novel ecosystems, created by intentional and unintentional introductions of nonnative species and land-use–facilitated spread of native ones. This framework simply divides decision making into two types: 1) straightforward–certain, and 2) complex–uncertain. We argue that management decisions to retain novel ecosystems are certain when goods and services provided by the system far outweigh the costs of restoration, for example in the case of intensively managed Cenchrus pastures. Decisions to return novel ecosystems to natural systems are also certain when the value of the system is low and restoration is easy and inexpensive as in the case of biocontrol of Opuntia infestations. In contrast, decisions whether to retain or restore novel ecosystems become complex and uncertain in cases where benefits are low and costs of control are high as, for example, in the case of stopping the expansion of Prosopis and Juniperus into semiarid rangelands. Decisions to retain or restore novel ecosystems are also complex and uncertain when, for example, nonnative Eucalyptus trees expand along natural streams, negatively affecting biodiversity, but also providing timber and honey. When decision making is complex and uncertain, we suggest that rangeland managers utilize cost–benefit analyses

  1. Perceptions of Ranchers About Medusahead ( Taeniatherum caput-medusae (L.) Nevski) Management on Sagebrush Steppe Rangelands

    NASA Astrophysics Data System (ADS)

    Johnson, Dustin D.; Davies, Kirk W.; Schreder, Peter T.; Chamberlain, Anna-Marie

    2011-09-01

    Medusahead ( Taeniatherum caput-medusae (L.) Nevski) is an exotic annual grass invading rangelands in the western United States. Medusahead is a serious management concern because it decreases biodiversity, reduces livestock forage production, and degrades the ecological function of rangelands. Despite the obvious importance of ranchers as partners in preventing and managing medusahead in rangelands, little is known about their perceptions and behaviors concerning medusahead management. We present the results of a survey of ranchers operating on sagebrush steppe rangeland in a three-county area in southeast Oregon encompassing over 7.2 million ha. The primary objective of this research was to determine if the presence of medusahead on a ranch influenced its operator's perceptions and behaviors concerning invasive plant control and prevention. Ranchers operating on medusahead-infested rangeland were more likely to indicate increased awareness and concern about medusahead and the potential for its continued expansion. Ranchers operating on rangeland invaded by medusahead were also more likely to indicate use of measures to prevent the spread of medusahead and other invasive plants on rangeland, interest in educational opportunities concerning invasive annual grass management, and plans for controlling invasive annual grasses in the future. This study revealed an alarming trend in which individuals are less likely to implement important prevention measures and participate in education opportunities to improve their knowledge of invasive plants until they directly experience the negative consequences of invasion. Information campaigns on invasive plants and their impacts may rectify this problem; however, appropriate delivery methods are critical for success. Web- or computer-based invasive plant information and tools were largely unpopular among ranchers, whereas traditional forms of information delivery including brochures/pamphlets and face-to-face interaction were

  2. Powerful motors: Kinship, citizenship and the transformation of the Argentine oil industry

    NASA Astrophysics Data System (ADS)

    Shever, Elana

    The privatization of the Argentine oil industry has been described as an unprecedented transfer of property, capital and control from the state to the corporate sphere, but this study demonstrates that the privatization process is better understood as a transformation of the historical configurations of oil-fueled development, political communities and human subjectivities. This dissertation probes the development of the state-led oil industry, and the shift to a corporate-led one, through an ethnography of Argentines differently positioned in relation to the global oil industry. The ethnography explores the lives of middle class oil workers and their families in Northwest Patagonia, impoverished residents of the shanty neighborhoods near the refineries in metropolitan Buenos Aires, and affluent employees of the translocal corporations operating in the Argentine oil fields. After the Introduction delineates this study's four principal interventions into anthropological scholarship, each subsequent chapter engages a particular problem that cuts across the Argentine oil fields and the anthropological theoretical fields. Chapter Two scrutinizes the historical construction of the Argentine subterritory as a "natural" space of value. Chapters Three and Four investigate the articulation of capitalist production and filial reproduction. These chapters argue that sentiment is a crucial generative force that has shaped the oil industry, company towns and worker families from the founding of the state-owned oil company in beginning of the twentieth century to its conversion into a corporate-owned one at the century's close. Chapters Five and Six examine the emergence of consumer citizenship and corporate citizenship out of Argentine neoliberalismo and its transformation of the oil industry. They argue that consumer and corporate citizenship are both reformulations of the older traditions of liberalism and Peronism. All the chapters of this dissertation illustrate that the

  3. Transitions in rangeland evaluations: A review of the major transitions in rangeland evaluations during the last 25 years and speculation about future evaluations

    Technology Transfer Automated Retrieval System (TEKTRAN)

    New technologies in remote sensing allow us to view land changes over much larger areas than in the past. Our increased understanding of the importance of linkages among the living components (all of the interacting organisms) and non-living components (e.g., soils, air, and water) of rangelands and...

  4. Modeling climate change effects on runoff and soil erosion in southeastern Arizona rangelands and implications for mitigation with rangeland conservation practices

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Climate change is expected to impact runoff and soil erosion on rangelands in the southwestern United States. This study was done to evaluate the potential impacts of precipitation changes on soil erosion and surface runoff in southeastern Arizona using seven GCM models with three emission scenarios...

  5. Abiotic factors control invasion by Argentine ants at the community scale.

    PubMed

    Menke, Sean B; Holway, David A

    2006-03-01

    1. A prominent and unresolved question in ecology concerns why communities differ in their susceptibility to invasion. While studies often emphasize biotic resistance, it is less widely appreciated how the physical environment affects community vulnerability to invasion. 2. In this study we performed field experiments to test how abiotic variation directly and indirectly influences the extent to which Linepithema humile Mayr (Argentine ants) invade seasonally dry environments in southern California. 3. In controlled and replicated experiments involving drip irrigation, we demonstrate (i) that elevated levels of soil moisture increased both the abundance of Argentine ants and their ability to invade native ant communities and (ii) that cessation of irrigation caused declines in the abundance of Argentine ants and led to their withdrawal from previously occupied areas. 4. Because drip irrigation stimulated plant growth, in an additional experiment we manipulated both soil moisture and plant cover to assess the direct vs. indirect effects of added water on the abundance of L. humile. 5. Local abundance of Argentine ants increased in irrigated plots but was 38% higher in irrigated plots with plants compared to irrigated plots where plant growth was suppressed. The results of this experiment thus argue for a direct role of soil moisture in influencing Argentine ant abundance but suggest that that the indirect effects of added water may also be important. 6. Our study illustrates more generally that fine-scale variation in the physical environment can control whether communities become invaded by non-native species and suggests that an understanding of community susceptibility to invasion will be improved by a better appreciation of interactions between the biotic and abiotic environment. PMID:16637990

  6. Comparison of rangeland vegetation sampling techniques in the Central Grasslands

    USGS Publications Warehouse

    Stohlgren, T.J.; Bull, K.A.; Otsuki, Y.

    1998-01-01

    Maintaining native plant diversity, detecting exotic species, and monitoring rare species are becoming important objectives in rangeland conservation. Four rangeland vegetation sampling techniques were compared to see how well they captured local pant diversity. The methods tested included the commonly used Parker transects, Daubenmire transects as modified by the USDA Forest Service, a new transect and 'large quadrat' design proposed by the USDA Agricultural Research Service, and the Modified-Whittaker multi-scale vegetation plot. The 4 methods were superimposed in shortgrass steppe, mixed grass prairie, northern mixed prairie, and tallgrass prairie in the Central Grasslands of the United States with 4 replicates in each prairie type. Analysis of variance tests showed significant method effects and prairie type effects, but no significant method X type interactions for total species richness, the number of native species, the number of species with less than 1 % cover, and the time required for sampling. The methods behaved similarly in each prairie type under a wide variety of grazing regimens. The Parker, large quadrat, and Daubenmire transects significantly underestimated the total species richness and the number of native species in each prairie type, and the number of species with less than 1 % cover in all but the tallgrass prairie type. The transect techniques also consistently missed half the exotic species, including noxious weeds, in each prairie type. The Modified-Whittaker method, which included an exhaustive search for plant species in a 20 x 50 m plot, served as the baseline for species richeness comparisons. For all prairie types, the Modified-Whittaker plot captured an average of 42. (?? 2.4; 1 S.E.) plant species per site compared to 15.9 (?? 1.3), 18.9 (?? 1.2), and 22.8 (?? 1.6) plant species per site using the Parker, large quadrat, and Daubenmire transect methods, respectively. The 4 methods captured most of the dominant species at each site

  7. Incorporating grazing into an eco-hydrologic model: Simulating coupled human and natural systems in rangelands

    NASA Astrophysics Data System (ADS)

    Reyes, J. J.; Liu, M.; Tague, C.; Choate, J. S.; Evans, R. D.; Johnson, K. A.; Adam, J. C.

    2013-12-01

    Rangelands provide an opportunity to investigate the coupled feedbacks between human activities and natural ecosystems. These areas comprise at least one-third of the Earth's surface and provide ecological support for birds, insects, wildlife and agricultural animals including grazing lands for livestock. Capturing the interactions among water, carbon, and nitrogen cycles within the context of regional scale patterns of climate and management is important to understand interactions, responses, and feedbacks between rangeland systems and humans, as well as provide relevant information to stakeholders and policymakers. The overarching objective of this research is to understand the full consequences, intended and unintended, of human activities and climate over time in rangelands by incorporating dynamics related to rangeland management into an eco-hydrologic model that also incorporates biogeochemical and soil processes. Here we evaluate our model over ungrazed and grazed sites for different rangeland ecosystems. The Regional Hydro-ecologic Simulation System (RHESSys) is a process-based, watershed-scale model that couples water with carbon and nitrogen cycles. Climate, soil, vegetation, and management effects within the watershed are represented in a nested landscape hierarchy to account for heterogeneity and the lateral movement of water and nutrients. We incorporated a daily time-series of plant biomass loss from rangeland to represent grazing. The TRY Plant Trait Database was used to parameterize genera of shrubs and grasses in different rangeland types, such as tallgrass prairie, Intermountain West cold desert, and shortgrass steppe. In addition, other model parameters captured the reallocation of carbon and nutrients after grass defoliation. Initial simulations were conducted at the Curlew Valley site in northern Utah, a former International Geosphere-Biosphere Programme Desert Biome site. We found that grasses were most sensitive to model parameters affecting

  8. Reorienting land degradation towards sustainable land management: linking sustainable livelihoods with ecosystem services in rangeland systems.

    PubMed

    Reed, M S; Stringer, L C; Dougill, A J; Perkins, J S; Atlhopheng, J R; Mulale, K; Favretto, N

    2015-03-15

    This paper identifies new ways of moving from land degradation towards sustainable land management through the development of economic mechanisms. It identifies new mechanisms to tackle land degradation based on retaining critical levels of natural capital whilst basing livelihoods on a wider range of ecosystem services. This is achieved through a case study analysis of the Kalahari rangelands in southwest Botswana. The paper first describes the socio-economic and ecological characteristics of the Kalahari rangelands and the types of land degradation taking place. It then focuses on bush encroachment as a way of exploring new economic instruments (e.g. Payments for Ecosystem Services) designed to enhance the flow of ecosystem services that support livelihoods in rangeland systems. It does this by evaluating the likely impacts of bush encroachment, one of the key forms of rangeland degradation, on a range of ecosystem services in three land tenure types (private fenced ranches, communal grazing areas and Wildlife Management Areas), before considering options for more sustainable land management in these systems. We argue that with adequate policy support, economic mechanisms could help reorient degraded rangelands towards more sustainable land management. PMID:25617787

  9. Identifying high production, low production and degraded rangelands in Senegal with normalized difference vegetation index data

    USGS Publications Warehouse

    Tappan, G. Gray; Wood, Lynette; Moore, Donald G.

    1993-01-01

    Seasonal herbaceous vegetation production on Senegal's native rangelands exhibits high spatial and temporal variability. This variability can be monitored using normalized difference vegetation index (NDVI) data computed from 1-km resolution Advanced Very High Resolution Radiometer (AVHRR) image data. Although annual fluctuations in rainfall account for some of the variability, numerous long-term production patterns are evident in the AVHRR time-series data. Different n productivity reflect variations in the region's climate, topography, soils, and land use. Areas of overgrazing and intensive cultivation have caused long-term soil and vegetation degradation. Rangelands of high and low productivity, and degraded rangelands were identified using NDVI. Time-series image data from 1987 though 1992 were used to map relative rangeland productivity. The results were compared to detailed resource maps on soils, vegetation and land use. Much of the variation in rangeland productivity correlated well to the known distribution of resources. The study developed an approach that identified a number of areas of degraded soils and low vegetation production.

  10. Seasonal food habits of swift fox (Vulpes velox) in cropland and rangeland landscapes in western Kansas

    USGS Publications Warehouse

    Sovada, M.A.; Roy, C.C.; Telesco, D.J.

    2001-01-01

    Food habits of swift foxes (Vulpes velox) occupying two distinct landscapes (dominated by cropland versus rangeland) in western Kansas were determined by analysis of scats collected in 1993 and 1996. Frequencies of occurrence of prey items in scats were compared between cropland and rangeland areas by season. Overall, the most frequently occurring foods of swift foxes were mammals (92% of all scats) and arthropods (87%), followed by birds (24%), carrion (23%), plants (15%) and reptiles (4%). No differences were detected between landscapes for occurrence of mammals, arthropods or carrion in any season (P ??? 0.100). Plants, specifically commercial sunflower seeds, were consumed more frequently in cropland than in rangeland in spring (P = 0.004) and fall (P = 0.001). Birds were more common in the swift fox diet in cropland than in rangeland during the fall (P = 0.008), whereas reptiles occurred more frequently in the diet in rangeland than in cropland during spring (P = 0.042). Variation in the diet of the swift fox between areas was most likely due to its opportunistic foraging behavior, resulting in a diet that closely links prey use with availability.

  11. Discriminating indicator grass species for rangeland degradation assessment using hyperspectral data resampled to AISA Eagle resolution

    NASA Astrophysics Data System (ADS)

    Mansour, Khalid; Mutanga, Onisimo; Everson, Terry; Adam, Elhadi

    2012-06-01

    The development of techniques to estimate and map increaser grass species is critical for better understanding the condition of the rangeland and levels of rangeland degradation. This paper investigates whether canopy reflectance spectra, resampled to AISA Eagle resolution can discriminate among four increaser species representing different levels of rangeland degradation. Canopy spectral measurements were taken from the four indicator species: Hyparrhenia hirta (HH), Eragrostis curvula (EC), Sporobolus africanus (SA), and Aristida diffusa (AD). The random forest algorithm and a forward variable selection technique were used to identify optimal wavelengths for discriminating the species. Results revealed that the optimal number of wavelengths (n = 8) that yielded the lowest OOB error (11.36%) in discriminating among the four increaser species are located in 966.7, 877.6, 691.9, 718.7, 902.7, 854.8, 674.1 and 703 nm. These wavelengths are located in the visible, red-edge and near-infrared regions of the electromagnetic spectrum. The random forest algorithm can accurately discriminate species with an overall accuracy of 88.64% and a KHAT value of 0.85. The study demonstrated the possibility to upscale the method to airborne sensors such as AISA Eagle for mapping indicator species of rangeland degradation. A rotational grazing management plan should be considered as a way to create sustainable rangeland management in degraded areas.

  12. Process for recovering actinide values

    DOEpatents

    Horwitz, E. Philip; Mason, George W.

    1980-01-01

    A process for rendering actinide values recoverable from sodium carbonate scrub waste solutions containing these and other values along with organic compounds resulting from the radiolytic and hydrolytic degradation of neutral organophosphorous extractants such as tri-n butyl phosphate (TBP) and dihexyl-N,N-diethyl carbamylmethylene phosphonate (DHDECAMP) which have been used in the reprocessing of irradiated nuclear reactor fuels. The scrub waste solution is preferably made acidic with mineral acid, to form a feed solution which is then contacted with a water-immiscible, highly polar organic extractant which selectively extracts the degradation products from the feed solution. The feed solution can then be processed to recover the actinides for storage or recycled back into the high-level waste process stream. The extractant is recycled after stripping the degradation products with a neutral sodium carbonate solution.

  13. METHOD OF RECOVERING URANIUM COMPOUNDS

    DOEpatents

    Poirier, R.H.

    1957-10-29

    S>The recovery of uranium compounds which have been adsorbed on anion exchange resins is discussed. The uranium and thorium-containing residues from monazite processed by alkali hydroxide are separated from solution, and leached with an alkali metal carbonate solution, whereby the uranium and thorium hydrorides are dissolved. The carbonate solution is then passed over an anion exchange resin causing the uranium to be adsorbed while the thorium remains in solution. The uranium may be recovered by contacting the uranium-holding resin with an aqueous ammonium carbonate solution whereby the uranium values are eluted from the resin and then heating the eluate whereby carbon dioxide and ammonia are given off, the pH value of the solution is lowered, and the uranium is precipitated.

  14. Grasshopper (Orthoptera: Acrididae) Community Composition in the Rangeland of the Northern Slopes of the Qilian Mountains in Northwestern China

    PubMed Central

    Sun, T.; Liu, Z. Y.; Qin, L. P.; Long, R. J.

    2015-01-01

    In order to describe grasshopper (Orthoptera: Acrididae) species composition, diversity, abundance, and density of four rangelands types, we compared the grasshopper community composition and dynamics in the rangeland of the northern slopes of the Qilian Mountains. In total, 55 grasshopper species were collected from 2007 to 2009, representing three families and six subfamilies. The subfamily Oedipodinae was dominant, followed by Gomphocerinae and Catantopinae. Species abundance varied among rangeland types (RTs). The greatest abundance of grasshoppers was found in mountain rangeland, while the lowest abundance of grasshoppers was caught in alpine shrublands. Three species (Chorthippus cf. brunneus (Thunberg) (Acrididae), Chorthippus Dubius (Zubovski), and Gomphocerus licenti (Chang) were broadly distributed in the four RTs and constituted 7.5% of all grasshoppers collected. Ch. dubius was very abundant in desert rangeland and alpine shrubland. Bryodema dolichoptera Yin et Feng Eremippus qilianshanensis Lian and Zheng, and Filchnerella qilianshanensis Xi and Zheng (Pamphagidae) were endemic to the region of the Qilian Mountains. Species similarity between RTs ranged from 17.8 to 51.6 based on the Renkonen index. Similarly, the Sörensen index indicated a wide separation in species composition among RTs. The abundance of the eight most common species showed obvious differences among RTs and years. On average, mountain rangeland had the highest density values in 2007 and 2008, and alpine shrubland supported the smallest density. The densities in desert and mountain rangeland in 2007 were significantly higher than in 2008, while alpine rangeland and shrublands did not present obvious differences among years. PMID:25688084

  15. Effects of long-term livestock grazing on fuel characteristics in rangelands: an example from the sagebrush steppe

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Livestock grazing potentially has substantial influence on fuel characteristics in rangelands around the globe. However, information quantifying the impacts of grazing on rangeland fuel characteristics is limited and the effects of grazing on fuels are important because fuels characteristics are on...

  16. Modeling vegetation heights from high resolution stereo aerial photography: an application for broad-scale rangeland monitoring

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Vertical vegetation structure in rangeland ecosystems can be a valuable indicator for monitoring rangeland health or progress toward management objectives because of its importance for assessing riparian areas, post-fire recovery, wind erosion, and wildlife habitat. Federal land management agencies ...

  17. Grasshopper (Orthoptera: Acrididae) community composition in the rangeland of the northern slopes of The Qilian Mountains in northwestern China.

    PubMed

    Sun, T; Liu, Z Y; Qin, L P; Long, R J

    2015-01-01

    In order to describe grasshopper (Orthoptera: Acrididae) species composition, diversity, abundance, and density of four rangelands types, we compared the grasshopper community composition and dynamics in the rangeland of the northern slopes of the Qilian Mountains. In total, 55 grasshopper species were collected from 2007 to 2009, representing three families and six subfamilies. The subfamily Oedipodinae was dominant, followed by Gomphocerinae and Catantopinae. Species abundance varied among rangeland types (RTs). The greatest abundance of grasshoppers was found in mountain rangeland, while the lowest abundance of grasshoppers was caught in alpine shrublands. Three species (Chorthippus cf. brunneus (Thunberg) (Acrididae), Chorthippus Dubius (Zubovski), and Gomphocerus licenti (Chang) were broadly distributed in the four RTs and constituted 7.5% of all grasshoppers collected. Ch. dubius was very abundant in desert rangeland and alpine shrubland. Bryodema dolichoptera Yin et Feng Eremippus qilianshanensis Lian and Zheng, and Filchnerella qilianshanensis Xi and Zheng (Pamphagidae) were endemic to the region of the Qilian Mountains. Species similarity between RTs ranged from 17.8 to 51.6 based on the Renkonen index. Similarly, the Sörensen index indicated a wide separation in species composition among RTs. The abundance of the eight most common species showed obvious differences among RTs and years. On average, mountain rangeland had the highest density values in 2007 and 2008, and alpine shrubland supported the smallest density. The densities in desert and mountain rangeland in 2007 were significantly higher than in 2008, while alpine rangeland and shrublands did not present obvious differences among years. PMID:25688084

  18. Hierarchical object-based classification of ultra-high-resolution digital mapping camera (DMC) imagery for rangeland mapping and assessment

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Ultra high resolution digital aerial photography has great potential to complement or replace ground measurements of vegetation cover for rangeland monitoring and assessment. We investigated object-based image analysis (OBIA) techniques for classifying vegetation in southwestern U.S. arid rangelands...

  19. Concentrated flow experiments on burned and unburned sagebrush communities: Applications for the Rangeland Hydrology and Erosion Model.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The risk of increased runoff and water erosion is greater after fire on many rangelands. Recent experiments on steep sagebrush rangelands have shown that concentrated flow detachment and transport is the dominant postfire erosion process. Rainfall simulation studies have demonstrated that runoff a...

  20. Measurement of surface energy fluxes in a rangeland ecosystem and comparison with a multi-layer canopy model

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rangeland ecosystems are often characterized by a patchy mosaic of vegetation types, making measurement and modeling of surface energy fluxes particularly challenging. The purpose of this study was to evaluate surface energy fluxes measured using eddy correlation at three rangeland sites, and use ...

  1. A decade of advancement in understanding of rangeland hydrology and erosion and the effects of conservation practices

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Over the past decade the USDA-ARS Northwest Watershed Research Center (NWRC) has conducted extensive field research to quantify hydrologic and erosion effects of rangeland conservation practices and to develop and advance tools for rangeland assessment and management. Much of what was previously kn...

  2. Deriving shrub heights from high resolution stereo-pair aerial imagery: An application for broad-scale rangeland monitoring

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Vertical vegetation structure in rangeland ecosystems can be a valuable indicator for monitoring rangeland health or progress toward management objectives because of its importance for assessing riparian areas, post-fire recovery, wind erosion, and wildlife habitat. Federal land management agencies ...

  3. THE USDA-ARS CO2 FLUX NETWORK: VARIATION IN RANGELAND CO2 FLUX ACROSS YEARS AND ECOSYSTEMS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This research effort involved numerous ARS rangeland and pasture scientists from ten western states (ND, OK, TX, AZ, CO, WY, MT, UT, ID, OR) in cooperation with the Texas A&M University Blackland Research Center. The project focused on assessment of CO2 flux over native rangeland at each of the loc...

  4. Using common gardens and AFLP analyses to identify metapopulations of indigenous plant materials for rangeland revegetation in western USA

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Semiarid rangelands in the western USA are facing unprecedented challenges related to past mismanagement, invasive weedy species, wildfires, and climatic change. A diversity of plant species are needed to effectively revegetate these rangelands. Legumes indigenous to western North America are of p...

  5. Grazing management, season, and drought contributions to near-surface soil property dynamics and greenhouse gas flux in semiarid rangeland

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Semiarid rangelands provide an array of ecosystem services, yet the role of grazing management and environmental conditions to affect rangeland soil function is poorly understood. A study was conducted to assess effects of grazing management, season, and drought on soil property dynamics and greenh...

  6. Identifying geographically based metapopulations for development of plant materials indigenous to rangeland ecosystems of the western USA

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rangeland ecosystems account for about half of the earth's land surface. They play an important role in providing forage for livestock and wildlife, and they serve as critical watershed areas. Many of the world's rangelands have been degraded by overgrazing, marginal crop production, mineral and e...

  7. Utilizing common-garden and genetic diversity structure analysis to determine strategies for releasing wildland plant germplasm for rangeland revegetation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Semi-arid rangelands in the western North America face many challenges due to invasive weedy species, wildfires, and past mismanagement. A diversity of plant species are needed to effectively revegetate degraded rangelands in this expansive area. Legumes native to western North America are of inte...

  8. A suite of tools for monitoring and assessing impacts of road networks and off-road vehicle activity on rangelands

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Despite increasing amounts of transportation related activities on rangelands globally, few tools exist for assessing and monitoring impacts of roads, road networks and off-road vehicle traffic. This is in part due to an historical emphasis on grazing issues in rangelands and the complexity of monit...

  9. Use of rainfall simulation and concentrated flow experiments to characterize rangeland hydrologic and erosional processes in the Great Basin, USA

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Much of what is known about rangeland hydrology comes from short-term, poorly replicated studies of small (0.25 - 1 m2) field plots and personal observations of hydrologic behavior on gently sloping semi-arid shrub and grassland sites. Historical rangeland models have been largely based on these lim...

  10. Risk assessment of erosion from concentrated flow on rangelands using overland flow distribution and shear stress partitioning

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Erosion rates of overland flow on rangelands tend to be relatively low, but under certain conditions where flow is concentrated, soil loss can be significant. Therefore, a rangeland site can be highly vulnerable to soil erosion where overland flow is likely to concentrate and exert high shear stress...

  11. Physiological and environmental regulation of interannual variability in CO2 exchange on rangelands in the western United States

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Arid and semi-arid grazing lands (rangelands) may regularly shift between functioning as a carbon (C) sink and a C source in response to variability in precipitation and other climatic or environmental variables. We analyzed measurements of carbon dioxide (CO2) exchange from 8 native rangeland ecos...

  12. State and transition models: Theory, applications, and challenges. In: Briske, D.D. Rangeland Systems: Processes, Management and Challenges

    Technology Transfer Automated Retrieval System (TEKTRAN)

    State and transition models (STMs) are used for communicating about ecosystem change in rangelands and other ecosystems, especially the implications for management. The fundamental premise that rangelands can exhibit multiple states is now widely accepted. The current application of STMs for managem...

  13. Precipitation regulates the response of net ecosystem CO2 exchange to environmental variation on U.S. rangelands

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rangelands occupy about 50% of the Earth’s land surface and thus play an important role in the terrestrial carbon (C) cycle. For rangelands and other terrestrial ecosystems, the balance between photosynthetic uptake of carbon dioxide (CO2) and CO2 loss to respiration varies among years in response ...

  14. Ecological site-based assessments of wind and water erosion: Informing accelerated soil erosion management in rangelands

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This paper explores how soil erosion assessments structured across ecological sites can inform systems for managing accelerated soil erosion in rangelands. We evaluated wind and water erosion rates for five ecological sites in southern New Mexico, USA, using monitoring data and rangeland-specific wi...

  15. Recovering Radioactive Materials with OSRP team

    ScienceCinema

    None

    2010-01-08

    The National Nuclear Security Administration sponsors a program, executed by Los Alamos National Laboratory, to recover radioisotopes used by industry and academia and no longer needed. Called the "Offsite Source Recovery Program (OSRP), it has recovered

  16. Recovering Radioactive Materials with OSRP team

    SciTech Connect

    2008-04-30

    The National Nuclear Security Administration sponsors a program, executed by Los Alamos National Laboratory, to recover radioisotopes used by industry and academia and no longer needed. Called the "Offsite Source Recovery Program (OSRP), it has recovered

  17. Flow process in a rangeland catchment in California

    SciTech Connect

    Salve, R.; Tokunaga, Tetsu K.

    2000-09-01

    Emerging hydrology-related issues in California grasslands have directed attention towards the need to understand subsurface water flow within a complex, dynamic system. Tensiometers and neutron probes evaluated the subsurface hydrology of a rangeland catchment. Hydrological processes within the catchment varied both in space and time. Spatial variability was evident along the vertical profile and between the catchment slopes. Temporal variability in processes coincided with the seasons (i.e., wet winter, dry summer, and spring). From a water-balance equation developed for the catchment, we determined that there was significant variability both spatial and temporal in the amount of soil moisture lost to evapotranspiration and deep seepage. During the 16 month monitoring period there was a total of 50 cm of rainfall that fell in the catchment of which 9-55 cm was lost to evaporation and 37-79 cm to deep seepage. A simple deduction of the losses (evaporation and deep seepage) from the input (rainfall) shows that all monitored locations had a substantial decrease in the amount of water that was stored in the soil profile.

  18. Prediction methodology for contaminant transport from rangeland watersheds

    SciTech Connect

    Devaurs, M.A.; Springer, E.P.; Lane, L.J.; Langhorst, G.J.

    1988-01-01

    Weather on arid and semiarid lands can be extremely variable. Runoff is generally emphermeral, and high intensity, short-duration rainfall events are the major stimulus for runoff events. Transport of sediment and associated contaminants occurs with these infrequent events. Incorporation of variability in weather into any prediction technology is essential to provide accurate representations of climate-induced uncertainty in predictions of hydrologic response. The objective of this study is to investigate a method for including short-term climatic variations in analyses for contaminant transport from rangeland watersheds in arid/semiarid regions. Short term is defined here as a twenty to fifty time frame and it is assumed that lone term climatic fluctuations are not observed during this time. Also, most weather records are available for this time period; predictions of greater length are extrapolations of existing records unless corroborative data for longer term trends are collected. Predictions are being made with condensable uncertainty in the weather inputs even if the models for water, sediment, and contaminant transport are perfectly unknown. This study will incorporate uncertainty in weather inputs into the prediction process and address the ramifications of this uncertainty. Uncertainty introduced by improper model or parameter specification is only briefly addressed.

  19. Using 70-mm aerial photography to identify rangeland sites

    NASA Technical Reports Server (NTRS)

    Everitt, J. H.; Gerbermann, A. H.; Alaniz, M. A.; Bowen, R. L.

    1980-01-01

    A south Texas rangeland area was used as a study site to test the use of microdensitometry on 70-mm color-infrared and black-and-white photographs (scale 1:19,000) for distinguishing among 11 range sites (two brushland, seven grassland, two barren land) during the winter (February), spring (May), and summer (August) of 1976. Color-infrared photographs were also taken at a scale of 1:42,000 for the summer date. Film optical density readings were made on one color-infrared film with white light only. The best separations among density readings for all range sites were obtained using white light exposed on color-infrared film in the summer when vegetation was at peak foliage development. Results from this study indicate that 70-mm aerial color-infrared photography at a scale of 1:19,000 or 1:42,000 has good potential for identifying range sites in large and inaccessible areas, and could be a useful tool for range management.

  20. Retrieval of granular bait by the Argentine ant (Hymenoptera: Formicidae): effect of clumped versus scattered dispersion patterns.

    PubMed

    Silverman, Jules; Roulston, T'ai H

    2003-06-01

    Argentine ants, Linepithema humile (Mayr), use mass recruitment foraging, with clumped prey items being retrieved more efficiently than dispersed prey. However, in prior field experiments, granular baits, whether dispensed in containers or broadly scattered, had a similar impact on Argentine ant populations. In laboratory experiments, granular insecticide bait was encountered faster by Argentine ant workers and more granules were initially returned to the colony when the granules were scattered versus clumped. After 2 h, granules from both dispersion patterns were retrieved equally. Our results suggest that Argentine ant colonies adjust their foraging patterns to resources of different quality (prey versus bait). Also, foraging activity patterns for bait in the laboratory are consistent with prior field results demonstrating no efficacy advantages to discrete granular bait placements. PMID:12852629

  1. Argentine ant invasion associated with loblolly pines in the southeastern United States: minimal impacts but seasonally sustained.

    PubMed

    Rowles, Alexei D; Silverman, Jules

    2010-08-01

    Invasive ants are notorious for directly displacing native ant species. Although such impacts are associated with Argentine ant invasions (Linepithema humile) worldwide, impacts within natural habitat are less widely reported, particularly those affecting arboreal ant communities. Argentine ants were detected in North Carolina mixed pine-hardwood forest for the first time but were localized on and around loblolly pines (Pinus taeda), probably because of association with honeydew-producing Hemiptera. We explored the potential impacts of L. humile on arboreal and ground-foraging native ant species by comparing interspersed loblolly pines invaded and uninvaded by Argentine ants. Impacts on native ants were assessed monthly over 1 yr by counting ants in foraging trails on pine trunks and in surrounding plots using a concentric arrangement of pitfall traps at 1, 2, and 3 m from the base of each tree. Of floristics and habitat variables, higher soil moisture in invaded plots was the only difference between plot types, increasing confidence that any ant community differences were caused by Argentine ants. Overall patterns of impact were weak. Composition differed significantly between Argentine ant invaded and uninvaded trunks and pitfalls but was driven only by the presence of Argentine ants rather than any resulting compositional change in native ant species. Native ant abundance and richness were similarly unaffected by L. humile. However, the abundance of individual ant species was more variable. Although numbers of the arboreal Crematogaster ashmeadi (Myrmicinae) declined on and around invaded pines, epigeic Aphaenogaster rudis (Myrmicinae) remained the most abundant species in all plots. Argentine ant densities peaked in late summer and fall, therefore overlapping with most native ants. Unexpected was their continued presence during even the coldest months. We provide evidence that Argentine ants can invade and persist in native North Carolina forests, probably

  2. Assessing the Success of Postfire Reseeding in Semiarid Rangelands Using Terra MODIS

    NASA Technical Reports Server (NTRS)

    Chen, Fang; Weber, Keith T.; Scbnase, John L.

    2012-01-01

    Successful postfire reseeding efforts can aid rangeland ecosystem recovery by rapidly establishing a desired plant community and thereby reducing the likelihood of infestation by invasive plants. Although the success of postfire remediation is critical, few efforts have been made to leverage existing geospatial technologies to develop methodologies to assess reseeding success following a fire. In this study, Terra Moderate Resolution Imaging Spectroradiometer (MODIS) satellite data were used to improve the capacity to assess postfire reseeding rehabilitation efforts, with particular emphasis on the semiarid rangelands of Idaho. Analysis of MODIS data demonstrated a positive effect of reseeding on rangeland ecosystem recovery, as well as differences in vegetation between reseeded areas and burned areas where no reseeding had occurred (P,0.05). We conclude that MODIS provides useful data to assess the success of postfire reseeding.

  3. Long-term field trial to control the invasive Argentine ant (Hymenoptera: Formicidae) with synthetic trail pheromone.

    PubMed

    Nishisue, K; Sunamura, E; Tanaka, Y; Sakamoto, H; Suzuki, S; Fukumoto, T; Terayama, M; Tatsuki, S

    2010-10-01

    Previous short-term experiments showed that trail following behavior of the Argentine ant, Linepithema humile (Mayr) (Hymenoptera: Formicidae), can be disrupted by a high concentration of synthetic trail pheromone component (Z)-9-hexadecenal. In this study, a long-term field trial was conducted in 100-m2 plots of house gardens in an urban area of Japan to see whether the control effect on Argentine ants can be obtained by permeating synthetic trail pheromone from dispensers. The dispensers were placed in the experimental plots during the ant's active season (April-November) for 2 yr with monthly renewal. To estimate Argentine ant population density, foraging activity of Argentine ants in the study plots was monitored by monthly bait surveys. Throughout the study period, Argentine ant foraging activity was suppressed in the presence of the dispensers, presumably via trail forming inhibition. In contrast, the level of foraging activity was not different between treatment and no-treatment plots when the dispensers were temporarily removed, suggesting that treatment with pheromone dispensers did not suppress Argentine ant density in the treatment plots. Population decline may be expected with larger-scale treatment that covers a significant portion of the ant colony or with improvement in the potency of the disruptant. PMID:21061980

  4. Rangeland dynamics: investigating vegetation composition and structure of urban and exurban prairie dog habitat

    PubMed Central

    Hopson, Rebecca; Meiman, Paul

    2015-01-01

    Rapid human population growth and habitat modification in the western United States has led to the formation of urban and exurban rangelands. Many of these rangelands are also home to populations of black-tailed prairie dogs (Cynomys ludovicianus). Our study aimed to compare the vegetation composition of an urban and exurban rangeland, and explore the role that prairie dogs play in these systems. The percent absolute canopy cover of graminoids (grasses and grass-likes), forbs, shrubs, litter, and bare ground were estimated at sampling areas located on and off prairie dog colonies at an urban and an exurban site. Herbaceous forage quality and quantity were determined on plant material collected from exclosure cages located on the colony during the entire growing season, while a relative estimate of prairie dog density was calculated using maximum counts. The exurban site had more litter and plant cover and less bare ground than the urban site. Graminoids were the dominant vegetation at the exurban plots. In contrast, mostly introduced forbs were found on the urban prairie dog colony. However, the forage quality and quantity tests demonstrated no difference between the two colonies. The relative prairie dog density was greater at the urban colony, which has the potential to drive greater vegetation utilization and reduced cover. Exurban rangeland showed lower levels of impact and retained all of the plant functional groups both on- and off-colony. These results suggest that activities of prairie dogs might further exacerbate the impacts of humans in fragmented urban rangeland habitats. Greater understanding of the drivers of these impacts and the spatial scales at which they occur are likely to prove valuable in the management and conservation of rangelands in and around urban areas. PMID:25650011

  5. A Rangeland Hydrology and Erosion Model for Developing Ecological Site Descriptions

    NASA Astrophysics Data System (ADS)

    Nearing, M. A.; Hernandez, M.; Armendariz, G.; Barker, S.; Williams, C. J.

    2014-12-01

    Predicting soil erosion is common practice in natural resource management for assessing the effects of management practices and control techniques of soil productivity, sediment delivery and off site water quality. The Rangeland Hydrology and Erosion Model (RHEM) was designed for this purpose. RHEM is an event-based model that estimates runoff, erosion, and sediment delivery rates and volumes at the spatial scale of the hillslope and the temporal scale of as single rainfall event. It represents erosion processes under normal and fire-impacted rangeland conditions. Moreover, it adopts a new splash erosion and thin sheet -flow transport equation developed from rangeland data, and it links the model hydrologic and erosion parameters with rangeland plant community by providing a new system of parameter estimation equations based on 204 plots at 49 rangeland sites distributed across 15 western U.S. states. Testing was done using long-term runoff and erosion data from small semi-aridland catchments. One of our goals with this project is to develop a framework for incorporating key ecohydrologic information/relationships in Ecological Site Descriptions and thereby enhanced utility of Ecological Site Descriptions s for guiding management. These key ecohydrologic relationships govern the ecologic resilience of the various states and community phases on many rangeland ecological sites and are strongly affected by management practices, land use, and disturbances. However, ecohydrologic data and relationships are often missing in Ecological Site Descriptions and resilience-based state-and-transition models. In this study we applied the RHEM model to data from multiple points in several ecological sites in Arizona, New Mexico, and Utah to assess the utility of the model for informing these Ecological Site Descriptions.

  6. Biomass Increases Go under Cover: Woody Vegetation Dynamics in South African Rangelands.

    PubMed

    Mograbi, Penelope J; Erasmus, Barend F N; Witkowski, E T F; Asner, Gregory P; Wessels, Konrad J; Mathieu, Renaud; Knapp, David E; Martin, Roberta E; Main, Russell

    2015-01-01

    Woody biomass dynamics are an expression of ecosystem function, yet biomass estimates do not provide information on the spatial distribution of woody vegetation within the vertical vegetation subcanopy. We demonstrate the ability of airborne light detection and ranging (LiDAR) to measure aboveground biomass and subcanopy structure, as an explanatory tool to unravel vegetation dynamics in structurally heterogeneous landscapes. We sampled three communal rangelands in Bushbuckridge, South Africa, utilised by rural communities for fuelwood harvesting. Woody biomass estimates ranged between 9 Mg ha(-1) on gabbro geology sites to 27 Mg ha(-1) on granitic geology sites. Despite predictions of woodland depletion due to unsustainable fuelwood extraction in previous studies, biomass in all the communal rangelands increased between 2008 and 2012. Annual biomass productivity estimates (10-14% p.a.) were higher than previous estimates of 4% and likely a significant contributor to the previous underestimations of modelled biomass supply. We show that biomass increases are attributable to growth of vegetation <5 m in height, and that, in the high wood extraction rangeland, 79% of the changes in the vertical vegetation subcanopy are gains in the 1-3 m height class. The higher the wood extraction pressure on the rangelands, the greater the biomass increases in the low height classes within the subcanopy, likely a strong resprouting response to intensive harvesting. Yet, fuelwood shortages are still occurring, as evidenced by the losses in the tall tree height class in the high extraction rangeland. Loss of large trees and gain in subcanopy shrubs could result in a structurally simple landscape with reduced functional capacity. This research demonstrates that intensive harvesting can, paradoxically, increase biomass and this has implications for the sustainability of ecosystem service provision. The structural implications of biomass increases in communal rangelands could be

  7. Biomass Increases Go under Cover: Woody Vegetation Dynamics in South African Rangelands

    PubMed Central

    Mograbi, Penelope J.; Knapp, David E.; Martin, Roberta E.; Main, Russell

    2015-01-01

    Woody biomass dynamics are an expression of ecosystem function, yet biomass estimates do not provide information on the spatial distribution of woody vegetation within the vertical vegetation subcanopy. We demonstrate the ability of airborne light detection and ranging (LiDAR) to measure aboveground biomass and subcanopy structure, as an explanatory tool to unravel vegetation dynamics in structurally heterogeneous landscapes. We sampled three communal rangelands in Bushbuckridge, South Africa, utilised by rural communities for fuelwood harvesting. Woody biomass estimates ranged between 9 Mg ha-1 on gabbro geology sites to 27 Mg ha-1 on granitic geology sites. Despite predictions of woodland depletion due to unsustainable fuelwood extraction in previous studies, biomass in all the communal rangelands increased between 2008 and 2012. Annual biomass productivity estimates (10–14% p.a.) were higher than previous estimates of 4% and likely a significant contributor to the previous underestimations of modelled biomass supply. We show that biomass increases are attributable to growth of vegetation <5 m in height, and that, in the high wood extraction rangeland, 79% of the changes in the vertical vegetation subcanopy are gains in the 1-3m height class. The higher the wood extraction pressure on the rangelands, the greater the biomass increases in the low height classes within the subcanopy, likely a strong resprouting response to intensive harvesting. Yet, fuelwood shortages are still occurring, as evidenced by the losses in the tall tree height class in the high extraction rangeland. Loss of large trees and gain in subcanopy shrubs could result in a structurally simple landscape with reduced functional capacity. This research demonstrates that intensive harvesting can, paradoxically, increase biomass and this has implications for the sustainability of ecosystem service provision. The structural implications of biomass increases in communal rangelands could be

  8. Rangeland dynamics: investigating vegetation composition and structure of urban and exurban prairie dog habitat.

    PubMed

    Hopson, Rebecca; Meiman, Paul; Shannon, Graeme

    2015-01-01

    Rapid human population growth and habitat modification in the western United States has led to the formation of urban and exurban rangelands. Many of these rangelands are also home to populations of black-tailed prairie dogs (Cynomys ludovicianus). Our study aimed to compare the vegetation composition of an urban and exurban rangeland, and explore the role that prairie dogs play in these systems. The percent absolute canopy cover of graminoids (grasses and grass-likes), forbs, shrubs, litter, and bare ground were estimated at sampling areas located on and off prairie dog colonies at an urban and an exurban site. Herbaceous forage quality and quantity were determined on plant material collected from exclosure cages located on the colony during the entire growing season, while a relative estimate of prairie dog density was calculated using maximum counts. The exurban site had more litter and plant cover and less bare ground than the urban site. Graminoids were the dominant vegetation at the exurban plots. In contrast, mostly introduced forbs were found on the urban prairie dog colony. However, the forage quality and quantity tests demonstrated no difference between the two colonies. The relative prairie dog density was greater at the urban colony, which has the potential to drive greater vegetation utilization and reduced cover. Exurban rangeland showed lower levels of impact and retained all of the plant functional groups both on- and off-colony. These results suggest that activities of prairie dogs might further exacerbate the impacts of humans in fragmented urban rangeland habitats. Greater understanding of the drivers of these impacts and the spatial scales at which they occur are likely to prove valuable in the management and conservation of rangelands in and around urban areas. PMID:25650011

  9. Is the Invasive Species Listronotus bonariensis (Kuschel) (Coleoptera: Curculionidae) (Argentine Stem Weevil) a Threat to New Zealand Natural Grassland Ecosystems?

    PubMed Central

    Barratt, Barbara I. P.; Barton, Diane M.; Philip, Bruce A.; Ferguson, Colin M.; Goldson, Stephen L.

    2016-01-01

    Listronotus bonariensis (Argentine stem weevil) is a stem-boring weevil that has become a major pasture pest in New Zealand, and cool climate turf grass in Australia. This species is also frequently found in native tussock grassland in New Zealand. Laboratory and field trials were established to determine the risk posed to both seedlings and established plants of three native grass species compared to what happens with a common host of this species, hybrid ryegrass (L. perenne X L. multiflorum). Adult weevil feeding damage scores were higher on Poa colensoi and Festuca novae-zelandiae than Chionochloa rigida. Oviposition was lower on P. colensoi than hybrid ryegrass, and no eggs were laid on F. novae-zelandiae. In field trials using the same four species established as spaced plants L. bonariensis laid more eggs per tiller in ryegrass in a low altitude pasture site than in ryegrass in a higher altitude site. No eggs were found on the three native grass species at the tussock sites, and only low numbers were found on other grasses at the low altitude pasture site. Despite this, numbers of adult weevils were extracted from the plants in the field trials. These may have comprised survivors of the original weevils added to the plants, together with new generation weevils that had emerged during the experiment. Irrespective, higher numbers were recovered from the tussock site plants than from those from the pasture site. It was concluded that L. bonariensis is likely to have little overall impact, but a greater impact on native grass seedling survival than on established plants. PMID:27507979

  10. Developments in Monitoring Rangelands Using Remotely-Sensed Cross-Fence Comparisons

    NASA Astrophysics Data System (ADS)

    Kilpatrick, A. D.; Warren-Smith, S. C.; Read, J. L.; Lewis, M. M.; Ostendorf, B.

    2012-07-01

    This paper presents a new method for the use of earth-observation images to assess relative land condition over broad regions, using a cross-fence comparison methodology. It controls for natural spatial and temporal variables (e.g. rainfall, temperature soils, ecosystem) so that we can objectively monitor rangelands and other areas for the effects of management. The method has been tested with small and large scale theoretical models, as well as a case study in South Australian rangelands. This method can also be applied in other systems and experiments such as field trials of crop varieties as a robust spatial statistic.

  11. The source and market development of a premium product - Beef from the Argentine Pampas.

    PubMed

    Champredonde, M

    2008-07-01

    The two main features of beef from the Argentine Pampas are its quality and geographical origin. In addition to the normal aspects of meat quality detected by sensory panels or measured by scientific instruments, the quality of Pampean beef includes the powerful symbolic quality of pampas life - the immensity of the green grasslands and the culture of the gaucho, living on horseback or sipping mate while making an asado (barbecue). This review defines the qualities and geographical origin of Pampean beef, and explains their interrelationships in terms of animal breed, nutrition and production systems. The objective is to help secure Pampean beef against unfair encroachment from competing products which lack the true authenticity of beef from the Argentine Pampas. PMID:22062914

  12. Vitrification Demonstration with Argentine Ion Exchange Material in the Stir-Melter

    SciTech Connect

    Cicero-Herman, C.A.

    2002-06-28

    The Savannah River Technology Center (SRTC) is investigating the viability of vitrification treatment of Argentine ion exchange material as part of a Department of Energy (DOE) - Office of Science and Technology Development Task Plan. Bench-scale studies were performed by the SRTC to define the necessary vitrification process for this material. However, the process had to be demonstrated in a melter system before vitrification could be considered a viable treatment option.

  13. Draft Genome Sequences of Four Enterococcus faecium Strains Isolated from Argentine Cheese

    PubMed Central

    Martino, Gabriela P.; Quintana, Ingrid M.; Espariz, Martín; Blancato, Victor S.; Gallina Nizo, Gabriel; Esteban, Luis

    2016-01-01

    We report the draft genome sequences of four Enterococcus faecium strains isolated from Argentine regional cheeses. These strains were selected based on their technological properties, i.e., their ability to produce aroma compounds (diacetyl, acetoin, and 2,3-butanediol) from citrate. The goal of our study is to provide further genetic evidence for the rational selection of enterococci strains based on their pheno- and genotype in order to be used in cheese production. PMID:26847907

  14. Draft Genome Sequences of Four Enterococcus faecium Strains Isolated from Argentine Cheese.

    PubMed

    Martino, Gabriela P; Quintana, Ingrid M; Espariz, Martín; Blancato, Victor S; Gallina Nizo, Gabriel; Esteban, Luis; Magni, Christian

    2016-01-01

    We report the draft genome sequences of four Enterococcus faecium strains isolated from Argentine regional cheeses. These strains were selected based on their technological properties, i.e., their ability to produce aroma compounds (diacetyl, acetoin, and 2,3-butanediol) from citrate. The goal of our study is to provide further genetic evidence for the rational selection of enterococci strains based on their pheno- and genotype in order to be used in cheese production. PMID:26847907

  15. Survey of Argentine Health Researchers on the Use of Evidence in Policymaking

    PubMed Central

    Corluka, Adrijana; Hyder, Adnan A.; Segura, Elsa; Winch, Peter; McLean, Robert K. D.

    2015-01-01

    Objective In this study, Argentine health researchers were surveyed regarding their perceptions of facilitators and barriers to evidence-based policymaking in Argentina, as well as their publication activities, and research environment satisfaction. Methods A self-administered online survey was sent to health researchers in Argentina. The survey questions were based on a preceding qualitative study of Argentine health researchers, as well as the scientific literature. Results Of the 647 researchers that were reached, 226 accessed the survey, for a response rate of 34.9%. Over 80% of researchers surveyed had never been involved in or contributed to decision-making, while over 90% of researchers indicated they would like to be involved in the decision-making process. Decision-maker self-interest was perceived to be the driving factor in the development of health and healthcare policies. Research conducted by a research leader was seen to be the most influential factor in influencing health policy, followed by policy relevance of the research. With respect to their occupational environment, researchers rated highest and most favourably the opportunities available to present, discuss and publish research results and their ability to further their education and training. Argentine researchers surveyed demonstrated a strong interest and willingness to contribute their work and expertise to inform Argentine health policy development. Conclusion Despite Argentina’s long scientific tradition, there are relatively few institutionalized linkages between health research results and health policymaking. Based on the results of this study, the disconnect between political decision-making and the health research system, coupled with fewer opportunities for formalized or informal researcher/decision-maker interaction, contribute to the challenges in evidence informing health policymaking in Argentina. Improving personal contact and the building of relationships between

  16. Simulation-model evaluation of bovine tuberculosis-eradication strategies in Argentine dairy herds.

    PubMed

    Perez, Andres M; Ward, Michael P; Ritacco, Viviana

    2002-08-30

    We used stochastic modification of the Reed-Frost model to assess the impact of 14 different eradication strategies on bovine tuberculosis, under three scenarios of disease introduction, in Argentine dairy herds. All strategies investigated were based on a test-and-cull approach using either the caudal-fold test (CFT), the single cervical test (SCT), the gamma-interferon (gamma-IFN) test or a combination of these tests. The maximum, minimum and most-likely sensitivity and specificity were investigated in three scenarios simulating different epidemiological conditions. Simulation results were highly variable; therefore, it is difficult to predict the effect of disease-control strategies within individual herds. On average, the use of the SCT was less efficient in eradicating tuberculosis from the simulated herd than the CFT. Eradication would be achieved most efficiently by strategies in which the CFT was used assuming maximum possible sensitivity and specificity (difficult to achieve in the field) and/or the gamma-IFN test-which has both economical and logistical limitations to its widespread application in Argentina. When disease-control was simulated in situations in which herd tuberculosis prevalence is > or = 22%, all strategies we simulated were less efficient than herd depopulation. Considering that Argentine dairy producers are not compensated financially for cattle culled because of tuberculosis, eradication strategies currently used in the Argentine national tuberculosis eradication might not succeed. PMID:12163251

  17. Evaluating the capability of the enhanced Rangeland Hydrology and Erosion Model (RHEM) for modeling the soil erosion impact of disturbance on rangelands

    NASA Astrophysics Data System (ADS)

    Al-Hamdan, O. Z.; Hernandez, M.; Pierson, F. B.; Nearing, M.; Williams, C. J.; Stone, J. J.; Boll, J.; Weltz, M.

    2013-12-01

    In this study, enhancement of the application of RHEM has been made using a new approach for predicting concentrated flow erosion in order to expand its applicability to disturbed rangelands. The enhanced model was conceptualized based on observations and results of experimental studies on rangelands disturbed by fire and/or tree encroachment. The enhanced version of the model incorporates: a new stream power- based sediment detachment rate equation that applies a dynamic erodibility concept, a new concentrated flow width equation, and new empirical parameterization equations for estimating hydraulic friction and erodibility as a function of readily available vegetation cover and surface soil texture data. The enhanced version of the model was evaluated against rainfall simulation data for three different sites that exhibit some degree of disturbance by fire and/or tree encroachment. Evaluation results indicated the ability of the model to predict erosion at the plot scale within a satisfactory range of error. The new version of the model was able to match the predicted effect of disturbances across a wide range of ecological sites with diverse vegetation and ground cover conditions. The model performance indicates it can be used as a practical management tool for quantifying soil erosion under current conditions and for assessing accelerated soil erosion risks following rangeland disturbances, such as, wild fire, prescribed fire, and/or tree encroachment.

  18. Assessing the use of remotely sensed measurements for characterizing rangeland condition

    NASA Astrophysics Data System (ADS)

    Folker, Geoffrey P.

    There are over 233 million hectares (ha) of nonfederal grazing lands in the United States. Conventional field observation and sampling techniques are insufficient methods to monitor such large areas frequently enough to confidently quantify the biophysical state and assess rangeland condition over large geographic areas. In an attempt to enhance rangeland resource managers' abilities to monitor and assess these factors, remote sensing scientists and land resource managers have worked together to determine whether remotely sensed measurements can improve the ability to measure rangeland response to land management practices. The relationship between spectral reflectance patterns and plant species composition was investigated on six south-central Kansas ranches. Airborne multispectral color infrared images for 2002 through 2004 were collected at multiple times in the growing season over the study area. Concurrent with the image acquisition periods, ground cover estimates of plant species composition and biomass by growth form were collected. Correlation analysis was used to examine relationships among spectral and biophysical field measurements. Results indicate that heavily grazed sites exhibited the highest spectral vegetation index values. This was attributed to increases in low forage quality broadleaf forbs such as annual ragweed (Ambrosia artemisiifolia L.). Although higher vegetation index values have a positive correlation with overall above ground primary productivity, species composition may be the best indicator of healthy rangeland condition. A Weediness Index, which was found to be correlated with range condition, was also strongly linked to spectral reflectance patterns recorded in the airborne imagery.

  19. Rangeland assessment and monitoring methods guide - an interactive tool for selecting methods for assessment and monitoring

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A common concern expressed by land managers and biologists is that they do not know enough about the strengths and weaknesses of different field and remote-sensing methods for rangeland assessment and monitoring. The Methods Guide is a web-based tool and resource that provides researchers and manage...

  20. Feeding goats on scrubby Mexican rangeland and pasteurization: influences on milk and artisan cheese quality

    PubMed Central

    Hilario, Mario Cuchillo; Wrage, Nicole; Pérez-Gil R., Fernando

    2010-01-01

    The objective of this study was to evaluate the effect of foraging on local scrubby rangeland versus stable feeding with high-protein concentrate as well as the compulsory pasteurization process on goats’ milk and artisan soft cheese quality in terms of chemical composition and fatty acid profile. The results indicated that there were no significant differences in the energy, fat, or ash content of milk and cheese due to feeding; however, a significant influence of feeding on cheese protein and fatty acids in both milk and cheese was detected. Feeding on scrubby rangeland tended to increase the amounts of major polyunsaturated fatty acids in milk and cheese from goats. Pasteurization, which is mandatory in Mexico, did not alter the fatty acid concentrations in milk or cheese. Small goat-keepers using rangeland resources might claim better economical returns for products recognized as healthier. Further investigations to assure ecosystem sustainability of shrubby rangeland joined with economical evaluations and best animal management to avoid deleterious effects are recommended. PMID:20229357

  1. Monitoring rangeland health: A guide for pastoralists and other land managers in Eastern Africa

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This guide provides is written for people who want to design and implement a simple rangeland monitoring programme in eastern Africa that is based on ecological priniciples and reflects the status of key ecological processes. It outline a series of steps that enable community members and other land ...

  2. A technique for estimating rangeland canopy-gap size distributions from high resolution digital imagery

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The amount and distribution of gaps in vegetation canopy is a useful indicator of multiple ecosystem processes and functions. We describe a semi-automated approach for estimating canopy-gap size distributions in rangelands from high-resolution (HR) digital images using image interpretation by observ...

  3. Unmanned aircraft missions for rangeland remote sensing applications in the US National Airspace

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In recent years, civilian applications of unmanned aerial systems (UAS) have increased considerably due to their greater availability and the miniaturization of sensors, GPS, inertial measurement units, and other hardware. UAS are well suited for rangeland remote sensing applications, because of the...

  4. Rangeland remote sensing applications with unmanned aerial systems (UAS) in the national airspace: challenges and experiences

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In recent years, civilian applications of unmanned aerial systems (UAS) have increased considerably due to their greater availability and the miniaturization of sensors, GPS, inertial measurement units, and other hardware. UAS are well suited for rangeland remote sensing applications, because of the...

  5. The conservation-production interface in rangelands: Acknowledging tradeoffs and moving towards win-win solutions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Provision of wildlife habitat in rangelands, particularly for birds of conservation concern, is increasingly recognized as an important ecosystem service. Accommodating human use is also a key component of ecosystem management. Most remaining grassland bird habitat in the western Great Plains is pri...

  6. Launching the Counterattack: Interdisciplinary Deployment of Functional Traits to Repair Damaged Intermountain Rangelands

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Ecologists worldwide recognize that the novel ecosystems of the future will display radically different structure and function from ecosystems that have dominated the study of ecology up until the prsent time. Because of both abiotic and biotic obstacles, rangelands dominated by invasive plants are...

  7. Salinity mobilization and transport from rangelands: assessment, recommendations, and knowledge gaps

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The purpose of the salinity project is to improve the understanding of sources and transport mechanisms in rangeland catchments that deliver dissolved solids (salts) to streams within the Upper Colorado River Basin (UCRB) through a review of relevant literature on what is known about the impact of r...

  8. Mimosa tenuiflora as a Cause of Malformations in Ruminants in the Northeastern Brazilian Semiarid Rangelands

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Craniofacial anomalies, eye malformations, and permanent flexures of the forelimbs are common malformations seen in ruminants grazing semiarid rangelands of Northeastern Brazil. To investigate the cause of these malformations, we fed 2 suspected plants, Mimosa tenuiflora or Prosopis juliflora, to gr...

  9. Influence of Management on Soil Organic Carbon Dynamics in Northern Mixed-Grass Rangeland

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Grazing rangelands can influence plant community structure, soil chemical and physical properties, and the distribution and cycling of nutrients within the plant-soil system. Studies initiated in 1982 at the High Plains Grasslands Research Station near Cheyenne, Wyoming, have shown that after 12 yea...

  10. Surface roughness effects on concentrated flow erosion processes in rangelands pre- and post-fire

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Concentrated flow erosion is a major mechanism of soil erosion on disturbed rangeland hillslopes and is strongly influenced by surface roughness. In this study we evaluated the utility of terrestrial laser scanning (TLS) to assess effects of surface roughness on concentrated flow erosion processes ...

  11. A strategy for rangeland management based on best available knowledge and information

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Changes to rangeland systems are happening at spatial and temporal scales beyond the capability of our current knowledge and information systems. In this paper we look at how Web 2.0 tools such as wikis and crowd-sourcing and new technologies including mobile devices and massive online databases are...

  12. Hydrologic Vulnerability of Western US Rangelands in the Wake of Woodland Encroachment and Increasing Wildfire Activity

    NASA Astrophysics Data System (ADS)

    Williams, C. J.; Pierson, F. B.; Al-Hamdan, O. Z.; Kormos, P. R.

    2013-12-01

    Pinyon and juniper woodlands have dramatically increased their range in the past 150 years and currently occupy more than 30 million ha of the western US. Range expansion has primarily occurred through encroachment into sagebrush rangelands. Woodland expansion and infill on western rangelands have altered the ecological structure and function of these ecosystems and have made much of the western US prone to large severe wildfires. Early-succession woodlands are now burning in large, high-severity wildfires due to heavy woody-fuel loading and extensive horizontal-to-vertical fuel connectivity. Tree infill on late-succession woodlands coupled with extreme fire weather has increased the occurrence of large, high-severity woodland fires in recent decades. We investigated the effects of woodland encroachment and burning on hydrologic vulnerability at multiple woodlands and at a sagebrush rangeland in the early stages of woodland encroachment. Artificial rainfall and overland flow simulations were paired with vegetation and soil measures to evaluate ecohydrologic ramifications of woodland encroachment and burning at multiple spatial scales and over time. Our results provide insight into the ecohydrologic consequences of landscape-scale conversion of sagebrush rangelands to woodlands and the effects of increasing wildfire across this domain in the western US.

  13. Tipping points in rangeland social-ecological systems of the Southwest US: Past and present

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Background/Question/Methods: The advent of social-ecological system perspectives has led to new questions about the causes and consequences of global change. Nearly all research in rangeland ecosystems of the U.S. has focused on transitions in vegetation (such as grasslands to shrublands) casting h...

  14. 'Recovery', a new western wheatgrass cultivar with improved seedling establishment on rangelands

    Technology Transfer Automated Retrieval System (TEKTRAN)

    'Recovery' western wheatgrass (Pascopyrum smithii [Rydb.] A. Love) (Reg. No. CV-_____, PI ______) was released in December 2009 by the USDA-ARS, the U.S. Army Corps of Engineers-Engineer Research and Development Center, and the USDA-NRCS. Recovery was developed for reseedling rangelands following s...

  15. Introduction to the USDA-Agricultural Research Service Poisonous Plant Research Laboratory Special Rangelands Issue

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The USDA-ARS Poisonous Plant Research Labortory (PPRL) in Logan, UT will sponsor an edition of the magazine Rangelands. This paper provides a brief history and overview of the PPRL, mission statement, research objectives by CRIS, and the disciplines involved in the research....

  16. Carbon sequestration and rangelands: Effects of length of management practice and precipitation gradients

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Management of rangelands can aid in the mitigation of rising atmospheric CO2 concentrations via carbon (C) storage in plant biomass and soil organic matter, a process termed C sequestration. Management practices that increase soil nitrogen (N), such as interseeding of N-fixing legumes, have the grea...

  17. Origin, persistence, and resolution of the rotational grazing debate: Integrating human dimensions into rangeland research

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This synthesis examines the origins of the rotational grazing debate, identifies the major reasons for its persistence, and concludes with an approach for resolution. The debate originated from scientific and institutional responses to rangeland degradation in the US during the late 1800s. Rotationa...

  18. Lessons from community-based payment for ecosystem service schemes: from forests to rangelands.

    PubMed

    Dougill, Andrew J; Stringer, Lindsay C; Leventon, Julia; Riddell, Mike; Rueff, Henri; Spracklen, Dominick V; Butt, Edward

    2012-11-19

    Climate finance investments and international policy are driving new community-based projects incorporating payments for ecosystem services (PES) to simultaneously store carbon and generate livelihood benefits. Most community-based PES (CB-PES) research focuses on forest areas. Rangelands, which store globally significant quantities of carbon and support many of the world's poor, have seen little CB-PES research attention, despite benefitting from several decades of community-based natural resource management (CBNRM) projects. Lessons from CBNRM suggest institutional considerations are vital in underpinning the design and implementation of successful community projects. This study uses documentary analysis to explore the institutional characteristics of three African community-based forest projects that seek to deliver carbon-storage and poverty-reduction benefits. Strong existing local institutions, clear land tenure, community control over land management decision-making and up-front, flexible payment schemes are found to be vital. Additionally, we undertake a global review of rangeland CBNRM literature and identify that alongside the lessons learned from forest projects, rangeland CB-PES project design requires specific consideration of project boundaries, benefit distribution, capacity building for community monitoring of carbon storage together with awareness-raising using decision-support tools to display the benefits of carbon-friendly land management. We highlight that institutional analyses must be undertaken alongside improved scientific studies of the carbon cycle to enable links to payment schemes, and for them to contribute to poverty alleviation in rangelands. PMID:23045714

  19. Semiarid rangeland is resilient to summer fire and post-fire grazing utilization

    Technology Transfer Automated Retrieval System (TEKTRAN)

    1. Most wildfires occur during summer in the northern hemisphere, the area burned annually is increasing, and fire effects during this season are least understood. Livestock grazing is a primary use of rangelands affected by wildfire, but post-fire grazing management is not well-supported with dat...

  20. Livestock systems and rangeland degradation in the new World Atlas of Desertification

    NASA Astrophysics Data System (ADS)

    Zucca, Claudio; Reynolds, James F.; Cherlet, Michael

    2015-04-01

    Livestock systems and rangeland degradation in the new World Atlas of Desertification Land degradation and desertification (LDD), which are widespread in global rangelands, are complex processes. They are caused by multiple (but limited) number of biophysical and socioeconomic drivers that lead to an unbalance in the capacity of the land to sustainably produce ecosystem services and economic value. Converging evidence indicates that the key biophysical and socioeconomic drivers include agricultural or pastoral land use and management practices, population growth, societal demands (e.g., urbanization), and climate change (e.g., increasing aridity and drought). The new World Atlas of Desertification (WAD) describes these global issues, documents their spatial change, and highlights the importance of these drivers in relation to land degradation processes. The impacts of LDD on the atmosphere, on water and on biodiversity are also covered. The WAD spatially illustrates relevant types of livestock and rangeland management systems, related (over-under) use of resources, various management activities, and some of the common features and transitions that contribute to LDD. For example, livestock grazing in marginal areas is increasing due to competition with agricultural encroachment and, hence, vulnerable lands are under threat. The integration of stratified global data layers facilitates identifying areas where stress on the land system can be linked to underlying causal issues. One of the objectives of the new WAD is to provide synthesis and tools for scientists and stakeholders to design sustainable solutions for efficient land use in global rangelands.

  1. US forest service technical cooperation visit Badia Rangeland and irrigation analysis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A US Forest Service (USFS) team comprised of a rangeland management advisor, a dryland water resource, and irrigation specialist, and a Middle East program specialist visited Jordan to provide technical assistance to the Ministry of Agriculture-Water Harvesting Directorate (MoA) and the Hashemite Fu...

  2. UAS-derived imagery and terrain models for rangeland mapping and monitoring

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Images from satellites and piloted aircraft have been used extensively for mapping and monitoring rangelands, which comprise approximately 50% of the world’s land area. Unmanned aircraft systems (UAS) are ideally suited for monitoring these vast and remote areas, and derived data can bridge the gap ...

  3. Reflectance Measurements of Vegetation Communities in Arid Rangelands of New Mexico

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The USDA ARS Jornada Experimental Range (Jornada) in southern New Mexico and the Sevilleta National Wildlife Refuge (Sevilleta) in Central New Mexico are Long Term Ecological Research (LTER) sites that provide unique opportunities to study changing rangeland communities using remote sensing techniqu...

  4. Long-term effects of grazing and precipitation on carbon sequestration and microbial dynamics on rangelands

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Grazing at light to heavy stocking rates in northern mixed-grass rangeland increased C sequestration after 12 years (1982-1993); however, drought conditions 7 of the following 10 years (1993-2003) resulted in a 30% loss of the sequestered C where grazing was heavy with concurrent shifts in the plant...

  5. Contrasting watershed-scale trends in runoff and sediment yield complicate rangeland water resources planning

    NASA Astrophysics Data System (ADS)

    Berg, Matthew D.; Marcantonio, Franco; Allison, Mead A.; McAlister, Jason; Wilcox, Bradford P.; Fox, William E.

    2016-06-01

    Rangelands cover a large portion of the earth's land surface and are undergoing dramatic landscape changes. At the same time, these ecosystems face increasing expectations to meet growing water supply needs. To address major gaps in our understanding of rangeland hydrologic function, we investigated historical watershed-scale runoff and sediment yield in a dynamic landscape in central Texas, USA. We quantified the relationship between precipitation and runoff and analyzed reservoir sediment cores dated using cesium-137 and lead-210 radioisotopes. Local rainfall and streamflow showed no directional trend over a period of 85 years, resulting in a rainfall-runoff ratio that has been resilient to watershed changes. Reservoir sedimentation rates generally were higher before 1963, but have been much lower and very stable since that time. Our findings suggest that (1) rangeland water yields may be stable over long periods despite dramatic landscape changes while (2) these same landscape changes influence sediment yields that impact downstream reservoir storage. Relying on rangelands to meet water needs demands an understanding of how these dynamic landscapes function and a quantification of the physical processes at work.

  6. Assessing impacts of fire and post-fie mitigation on runoff and erosion from rangelands

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Wildfires are a natural component of rangeland ecosystems, but fires can pose hydrologic hazards for ecological resources, infrastructure, property, and human life. There has been considerable research conducted on the effects of fire on hydrologic processes and erosion on shrublands and woodlands....

  7. Orthorectification, mosaicking, and analysis of sub-decimeter resolution UAV imagery for rangeland monitoring

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Unmanned aerial vehicles (UAVs) offer an attractive platform for acquiring imagery for rangeland monitoring. UAVs can be deployed quickly and repeatedly, and they can obtain sub-decimeter resolution imagery at lower image acquisition costs than with piloted aircraft. Low flying heights result in ima...

  8. Application of a rangeland soil erosion model using NRI data in southeastern Arizona

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rangelands comprise a large portion of the western United States. They are important for providing ecosystem services such as sources of clean water and air, wildlife habitat, ecosystem biodiversity, recreation, and aesthetics. The National Resources Inventory (NRI) is a primary data source for on-...

  9. Approaches for mapping and monitoring arid rangelands with object-based image analysis and hyperspatial imagery

    Technology Transfer Automated Retrieval System (TEKTRAN)

    At the USDA Agricultural Research Service Jornada Experimental Range (JER) in southern New Mexico, remote sensing research is focused on finding new methods for mapping and monitoring rangelands, and on relating ground-based surveys to remotely sensed information. This presentation will give an over...

  10. Ground Based Reflectance Measurements of Arid Rangeland Vegetation Communities of the Southwestern United States

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In 1997 a research program began using an Analytical Spectral Device (ASD-FR) spectroradiometer to collect ground based in situ radiance/reflectance measurements from vegetation communities typical of semiarid/arid rangelands of southwestern United States. Measurements were made after the spring (Ap...

  11. Resilience theory in models of rangeland ecology and restoration: the evolution and application of a paradigm.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In this review, we will use our experiences and our ongoing collaborations to describe an approach that links new concepts regarding ecosystem dynamics to science, management and restoration activities in rangelands. First, we will review some novel elements and ideas connected to resilience theory ...

  12. Hydrologic and erosional impacts associated with an increased role of wildland fire on western rangelands

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Landscape plant community transitions across the Great Basin and Intermountain West have altered fire regimes and present large-scale consequences relative to rangeland hydrology. Extensive conversion of Great Basin shrub steppe to annual grasslands has increased fuel continuity and the frequency, ...

  13. AUTOMATED DIGITAL COVER ANALYSIS OF VERY-LARGE SCALE AERIAL (VLSA) RANGELAND IMAGES

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Vegetation cover and bare ground are key indicators of rangeland health. However, cover and bare ground assessments are often confounded by subjective evaluations, resulting in reduced measurement repeatability and questionable accuracy. Measurement methods, such as the point frame and line-intercep...

  14. An assessment of behavioral syndromes in rangeland-raised beef cattle

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Individuals in most animal groups exhibit consistent behavioural differences across situations or over time known as behavioural syndromes. We conducted a study with a herd of young rangeland-raised cows to determine whether animals exhibited consistent differences in foraging behaviours across cont...

  15. Tipping points in rangelands: The scales of social-biophysical interactions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Ecological and socio-economic processes are driving many of the world’s rangelands beyond “tipping points” to degraded states, but we have a poor understanding of the mechanisms by which these processes are linked to each other. We argue that this is due largely to the lack of data on region-scale p...

  16. Deriving empirical benchmarks from existing monitoring datasets for rangeland adaptive management

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Under adaptive management, goals and decisions for managing rangeland resources are shaped by requirements like the Bureau of Land Management’s (BLM’s) Land Health Standards, which specify desired conditions. Without formalized, quantitative benchmarks for triggering management actions, adaptive man...

  17. Ecosystem water availability in juniper versus sagebrush snow-dominated rangelands

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Western Juniper (J. occidentalis Hook.) now dominates over 3.6 million ha of rangeland in the Intermountain Western US. Critical ecological relationships among snow distribution, water budgets, plant community transitions, and habitat requirements for wildlife, such as sage grouse, remain poorly und...

  18. Lessons from community-based payment for ecosystem service schemes: from forests to rangelands

    PubMed Central

    Dougill, Andrew J.; Stringer, Lindsay C.; Leventon, Julia; Riddell, Mike; Rueff, Henri; Spracklen, Dominick V.; Butt, Edward

    2012-01-01

    Climate finance investments and international policy are driving new community-based projects incorporating payments for ecosystem services (PES) to simultaneously store carbon and generate livelihood benefits. Most community-based PES (CB-PES) research focuses on forest areas. Rangelands, which store globally significant quantities of carbon and support many of the world's poor, have seen little CB-PES research attention, despite benefitting from several decades of community-based natural resource management (CBNRM) projects. Lessons from CBNRM suggest institutional considerations are vital in underpinning the design and implementation of successful community projects. This study uses documentary analysis to explore the institutional characteristics of three African community-based forest projects that seek to deliver carbon-storage and poverty-reduction benefits. Strong existing local institutions, clear land tenure, community control over land management decision-making and up-front, flexible payment schemes are found to be vital. Additionally, we undertake a global review of rangeland CBNRM literature and identify that alongside the lessons learned from forest projects, rangeland CB-PES project design requires specific consideration of project boundaries, benefit distribution, capacity building for community monitoring of carbon storage together with awareness-raising using decision-support tools to display the benefits of carbon-friendly land management. We highlight that institutional analyses must be undertaken alongside improved scientific studies of the carbon cycle to enable links to payment schemes, and for them to contribute to poverty alleviation in rangelands. PMID:23045714

  19. Social-biophysical feedbacks and land change in an arid rangeland region

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Studies of human-dominated ecosystems have traditionally externalized human agents and their behavior. Rangelands of the southwestern U.S. are no exception: in spite of century-long studies of vegetation change, the specific role of human decisions and their feedbacks with land condition are unknown...

  20. Field validation of biomass retrieved from Landsat for rangeland assessment and monitoring

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Measures of terrestrial biomass that are accurate and repeatable are important to monitoring and modeling productivity in the world’s grassland and savanna (i.e., rangeland) ecosystems. Remote sensing offers potential to characterize seasonal changes in biomass in a consistent non-destructive manner...

  1. Monitoring spotted knapweed with very-large-scale-aerial imagery in sagebrush-dominated rangelands.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Spotted knapweed (Centaurea stoebe L.) invades and destroys productive rangelands. Monitoring weed infestations across extensive and remote landscapes can be difficult and costly. We evaluated the efficacy of very-large-scale-aerial (VLSA) imagery for detection and quantification of spotted knapwee...

  2. Improving restoration of exotic annual grass-invaded rangelands through activated carbon seed enhancement technologies

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cost-efficient strategies for revegetating annual grass-infested rangelands are limited. Restoration efforts typically comprise a combination of pre-emergent herbicide treatments and seeding to restore desired plant materials. However, practitioners struggle with applying herbicide at rates sufficie...

  3. INTERSEEDING MEDICAGO SATIVA SSP. FALCATA INTO RANGELANDS TO ENHANCE CARBON SEQUESTRATION AND FORAGE PRODUCTION

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rangelands of the U.S. Great Plains can generally be characterized as having low nitrogen levels, which along with water, are considered the major limiting factors in forage production. The purpose of this research was to assess the effect of interseeding Medicago sativa ssp. falcata on native range...

  4. Developing soil erodibility prediction equations for the Rangeland Hydrology and Erosion Model (RHEM)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Soil erodibility is a key factor for estimating soil erosion using physically based models. In this study, a new parameterization approach for estimating erodibility was developed for the Rangeland Hydrology and Erosion Model (RHEM). The approach uses empirical equations that were developed by apply...

  5. Potential of Kochia prostrata and perennial grasses for rangeland restoration in Jordan

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Six varieties of forage kochia [Kochia prostrata (L.) Shad.], three native shrubs, two introduced Atriplex shrub species native to cold deserts in the western United States and drought-tolerant perennial grass varieties were seeded and evaluated under arid rangeland conditions in Jordan. Varieties w...

  6. Functional group and species responses to spring precipitation in three semi-arid rangeland ecosystems

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Determining if precipitation-induced changes to forage production and basal and foliar cover in semi-arid rangelands are species-specific, functional group-specific or ubiquitous across species and functional groups will enhance decision making among producers and increase precision of forage produc...

  7. Weather variability, ecological processes and optimization of soil micro-environment for rangeland restoration

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Arid and semi-arid rangelands occupy over half of the earth’s surface and are characterized by relatively high variability in seasonal and annual patterns of precipitation. Invasive plants compete for soil and water resources and exacerbate inherent weather limitations for native plant establishmen...

  8. 75 FR 10754 - Humboldt-Toiyabe National Forests; Santa Rosa Ranger District; Martin Basin Rangeland Management...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-09

    ... authorize grazing on three of the allotments in the Project Area (the Buffalo, Granite Creek, and Rebel... grazing management. 2. No Grazing Alternative: Eliminate grazing in the Buffalo, Granite Creek, and Rebel... the Buffalo, Granite Creek, and Rebel Creek Allotments in the Martin Basin Rangeland Project area....

  9. 78 FR 73186 - Wallowa-Whitman National Forests, Oregon; Lower Imnaha Rangeland Analysis

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-05

    ...The USDA, Forest Service will prepare an environmental impact statement to authorize the approval of grazing livestock within the lower Imnaha area, including allotments within the Lightning Creek, Tulley Creek, Cow Creek, and a portion of the Snake River watersheds of the Hells Canyon National Recreation Area of the Wallowa-Whitman National Forest. The Lower Imnaha Rangeland Analysis (LIRA)......

  10. Restoration of exotic annual grass-invaded rangelands: importance of seed mix composition

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Restoration of exotic annual grass-invaded rangelands is needed to improve ecosystem function and services. Increasing plant species and plant functional group diversity is generally believed to increase resistance to invasion and increase desired vegetation. However, the effects of diversity and ...

  11. Multiscale variability of soil aggregate stability: implications for rangeland hydrology and erosion

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Conservation of soil and water resources in rangelands is a crucial step in stopping desertification processes. The formation of water-stable soil aggregates reduces soil erodibility and can increase infiltration capacity in many soils. Soil aggregate stability is highly variable at scales ranging f...

  12. Ecosystem water availability in juniper versus sagebrush snow-domintaed rangelands

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Western Juniper (J. occidentalis Hook.) now dominates over 3.6 million ha of rangeland in the Intermountain Western US. Critical ecological relationships among snow distribution, water budgets, plant community transitions, and habitat requirements for wildlife, such as sage grouse, remain poorly und...

  13. Assessing resilience of western rangelands to transportation-related land-use change

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The amount and extent of transportation related activity in western rangelands has rapidly increased in recent decades. This increase is due to a variety of factors including oil and gas development, recreational activities, and ex-urban development. In addition to areas directly impacted by infrast...

  14. Prediction of senescent rangeland canopy structural attributes with airborne hyperspectral imagery

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Canopy structural and chemical data are needed for senescent, mixed-grass prairie landscapes in autumn, yet models driven by image data are lacking for rangelands dominated by non-photosynthetically active vegetation (NPV). Here, we report how aerial hyperspectral imagery might be modeled to predic...

  15. Incorporation of texture, intensity, hue, and saturation for rangeland monitoring with unmanned aircraft imagery

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Aerial photography acquired with unmanned aerial vehicles (UAVs) has great potential for incorporation into rangeland health monitoring protocols, and object-based image analysis is well suited for this hyperspatial imagery. A major drawback, however, is the low spectral resolution of the imagery, b...

  16. Germination and seedling emergence of three western North American rangeland legumes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Few seed sources of North American forbs are available for revegetation/restoration of degraded western rangelands adapted to precipitation zones less than 300 mm, and those that are available are mainly wildland-collected. The amount of time and resources necessary to make wildland collections in ...

  17. Big questions emerging from a century of rangeland science and management

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This special feature commemorating the Jornada centennial addressed several big questions about the future of rangelands, including how livestock production can be sustained with reduced grass cover, responses to invasive species, and how to manage for diverse ecosystem services (among others)....

  18. Rangeland management for multiple outcomes: Explicity integrating ecosystem services into management models

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In recent decades, there has been increased interest in ecosystem services among landowners, and a growing diversity of stakeholders on rangelands. Given these changes, management cannot focus solely on maximizing ranch proceeds, but must also incorporate ecosystem service goals to sustain resources...

  19. Perennial grass dominance: creating a resilient plant community in an exotic annual grass invaded rangeland

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Millions of hectares of western rangelands have been invaded by the exotic and invasive annual grass, cheatgrass (Bromus tectorum). Cheatgrass provides a fine-textured, early maturing fuel that has increased the chance, rate, spread and season of wildfire to public and private lands throughout the ...

  20. Acquisition, orthorectification, and object-based classification of unmanned aerial vehicle (UAV) imagery for rangeland monitoring

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In this paper, we examine the potential of using a small unmanned aerial vehicle (UAV) for rangeland inventory, assessment and monitoring. Imagery with 8-cm resolution was acquired over 290 ha in southwestern Idaho. We developed a semi-automated orthorectification procedure suitable for handling lar...

  1. BIRD SPECIES ASSEMBLAGES AS INDICATORS OF BIOLOGICAL INTEGRITY IN GREAT BASIN RANGELAND

    EPA Science Inventory

    The study evaluates the potential for bird species assemblages to serve as indicators of biological integrity of rangelands in the Great Basin in much the same way that fish and invertebrate assemblages have been used as indicators in aquatic environments. Our approach was to ide...

  2. Disaggregation of soil map units for improved ecological site mapping in rangelands

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rangeland soils are often mapped with soil map units consisting of associations, complexes, and undifferentiated groups composed of varied soil components. Because different components may be related to different ecological sites, the unmapped heterogeneity within map units limits the potential uses...

  3. Disaggregation of Soil Map Units for Improved Ecological Site Mapping in Rangelands

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rangeland soils are often mapped with soil map units consisting of associations, complexes, and undifferentiated groups composed of varied soil components. Because different components may be related to different ecological sites, the unmapped heterogeneity within map units limits the potential uses...

  4. Remote sensing studies of arid rangelands in the southwestern United States

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The USDA ARS Jornada Experimental Range (Jornada) in southern New Mexico and the Sevilleta National Wildlife Refuge (Sevilleta) in Central New Mexico are Long Term Ecological Research (LTER) sites that provide unique opportunities to study changing rangeland conditions using remote sensing technique...

  5. Controls over the strength and timing of fire-grazer interactions in semiarid rangeland

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The degree to which large herbivores select and forage within recently burned areas is a key driver of vegetation heterogeneity in rangeland ecosystems. Yet few studies have carefully quantified the strength and timing of herbivore selection for burns or how selection strength varies among ecosystem...

  6. Variable Impacts of Imazapic on Downy Brome (Bromus Tectorum) and Seeded Species in Two Rangeland Communities

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In the Great Basin desert of North America, over 20 million acres of land have been invaded by downy brome. A common control measure includes herbicide use combined with seeding of desirable species. The herbicide imazapic is registerred for use on rangelands and provides effective short-term cont...

  7. Use of RHEM to assess runoff and erosion following disturbance on rangelands

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Landscape disturbance such as fire or woody plant encroachment on rangelands can have major impacts on the hydrological and erosion responses. As canopy and ground cover are reduced, soil sediments become available and can be detached by rain splash and overland flow. Disturbance can also increase t...

  8. Climate-change adaptation on rangelands: Linking regional exposure with diverse adaptive capacity

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The ecological consequences of climate change are anticipated to vary greatly throughout North American rangelands. Projections are for warming and drying in the southern plains, southwest and northern Mexico; warmer, drier summers, with reduced winter snowpack in northwest; and warmer, wetter condi...

  9. Potential for Use of Kochia Prostrata and Perennial Grasses for Use in Rangeland Rehabilitation in Jordan

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Six varieties of forage kochia [Kochia prostrata (L.) Shad.], three native shrubs, two introduced Atriplex shrub species native to cold deserts in the western United States and drought-tolerant perennial grass varieties were seeded and evaluated under arid rangeland conditions in Jordan. Varieties ...

  10. Mitigation of larkspur poisoning on rangelands through the selection of cattle

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Toxic larkspur (Delphinium species) in the western United States cause large economic losses from cattle deaths, increased management costs, and reduced utilization of pastures and rangelands. Peak larkspur toxicity coincides with maximum productivity of the range, which reduces the profitability of...

  11. Assessing impacts of fire and post-fire mitigation on runoff and erosion from rangelands

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Wildfires are a natural component of rangeland ecosystems, but fires can pose hydrologic hazards for ecological resources, infrastructure, property, and human life. There has been considerable research conducted on the effects of fire on hydrologic processes and erosion on shrublands and woodlands....

  12. Arguments for a major research focus on seeding establishment and recruitment on rangelands

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Understanding vegetation change is the basis for much of the rangeland management profession. Yet we know little about seedling ecology, from the standpoint of either reseeding or natural recruitment. We often view vegetation over long time horizons to allow changes to manifest themselves. If we lac...

  13. Using very-large-scale aerial imagery for rangeland monitoring and assessment: Some statistical considerations

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The availability of very-high-resolution (VHR) imagery and techniques for processing those data into indicators of ecosystem function has opened the door for VHR imagery to be used in rangeland monitoring and assessment. However, VHR imagery can be expensive and, like any survey measurement, studies...

  14. Spatially explicit rangeland erosion monitoring using high-resolution digital aerial imagery

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Nearly all of the ecosystem services supported by rangelands, including production of livestock forage, carbon sequestration, and provisioning of clean water, are negatively impacted by soil erosion. Accordingly, monitoring the severity, spatial extent, and rate of soil erosion is essential for long...

  15. Insight into sediment transport processes on saline rangeland hillslopes using three-dimensional soil microtoprgraphy changes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Hillslope runoff and soil erosion processes play a vital role on rangeland ecosystem sustainability due to their control on resource mobility but they also have significant implications in off-site resource transport. In general, physically-based soil erosion models such as RHEM divide erosion and ...

  16. The importance of persistent monitoring of great basin rangeland rehabilitation efforts

    Technology Transfer Automated Retrieval System (TEKTRAN)

    It has long been acknowledged the drastic change in fire cycles of the Great Basin rangelands due to cheatgrass (Bromus tectorum) invasion (Billings 1952, Young and Evans 1974, Wright 1980). An annual grass fire cycle now exists with return intervals less than 5 years compared to historical 60 to110...

  17. Revolutionary land use change in the 21st century: Is (rangeland) science relevant?

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rapidly increasing demand for food, fiber and fuel together with new technologies and the mobility of global capital are driving revolutionary changes in land use throughout the world. Efforts to increase land productivity include conversion of millions of hectares of rangelands to crop production, ...

  18. A review of concentrated flow erosion processes on rangelands: fundamental understanding and knowledge gaps

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Concentrated flow erosion processes are distinguished from splash and sheetflow processes in their enhanced ability to mobilize and transport large amounts of soil, water and dissolved elements. On rangelands, soil, nutrients and water are scarce and only narrow margins of resource losses are tolera...

  19. Unmanned aerial vehicles for hyperspatial remote sensing of rangelands: object-based classification and field validation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    UAVs are ideally suited for monitoring and assessing vegetation conditions in remote rangelands due to the relatively low operating costs, ability for fast deployment, and greater flexibility than piloted aircraft. The likelihood of obtaining FAA permission for operating a UAV is also greater in rem...

  20. Movement and spatial proximity patterns of rangeland-raised Raramuri Criollo cow-calf pairs

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The objective of this study was to compare movement patterns of nursing vs. nonnursing mature cows and to characterize cow-calf proximity patterns in two herds of Raramuri Criollo cattle. Herds grazed rangeland pastures in southern New Mexico (4355 ha) and west-central Chihuahua, Mexico (633 ha)'' A...

  1. North American Legumes for Rangeland Restoration, Conservation, and Forage Production in the Western U.S.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Land managers do not have many alternatives to choose from when seeding North American legume species on rangelands of the western U.S. As part of an initiative to address that need, research was conducted with basalt milkvetch (Astragalus filipes), western prairie clover (Dalea ornata), and Searls...

  2. Effects of Grazing Pressure on Efficiency of Grazing on North American Great Plains Rangelands

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Robust prediction models describing vegetation and animal responses to stocking rate in North American Great Plains rangelands are lacking as across site comparisons are limited by different qualitative designations of light, moderate and heavy stocking. Comparisons of stocking rates across sites ca...

  3. The Haleakala Argentine ant project: a synthesis of past research and prospects for the future.

    USGS Publications Warehouse

    Krushelnycky, Paul; Haines, William; Loope, Lloyd; Van Gelder, Ellen

    2011-01-01

    1. The Haleakala Argentine Ant Project is an ongoing effort to study the ecology of the invasive Argentine ant in the park, and if possible to develop a strategy to control this destructive species. 2. Past research has demonstrated that the Argentine ant causes very significant impacts on native arthropods where it invades, threatening a large portion of the park’s biodiversity in subalpine shrubland and alpine aeolian ecosystems. 3. Patterns of spread over the past 30+ years indicate that the invasion process is influenced to a substantial degree by abiotic factors such as elevation, rainfall and temperature, and that the ant has not reached its potential range. Predictions of total range in the park suggest that it has only invaded a small fraction of available suitable habitat, confirming that this species is one of most serious threats to the park’s natural resources. 4. Numerous experiments have been conducted since 1994 in an attempt to develop a method for eradicating the Argentine ant at Haleakala using pesticidal ant baits. Thirty baits have been screened for attractiveness to ants in the park, and ten of these were tested for effectiveness of control in field plots. While some of these baits have been very effective in reducing numbers of ants, none has been able to eliminate all nests in experimental plots. 5. Research into a secondary management goal of ant population containment was initiated in 1996. By treating only expanding margins of the park’s two ant populations with an ant pesticide, rates of outward spread were substantially reduced in some areas. While this strategy was implemented from 1997 to 2004, it was ultimately discontinued after 2004 because of the difficulty and insufficient effectiveness of the technique. 6. In order to achieve the types of results necessary for eradication, the project would probably need to explore the possibility of developing a specialized bait, rather than relying on a commercially produced bait. An

  4. Comparisons of pastoralists perceptions about rangeland resource utilisation in the Middle Awash Valley of Ethiopia.

    PubMed

    Abule, E; Snyman, H A; Smit, G N

    2005-04-01

    Pastoralism is the most dominant land use form in the arid rangelands of Sub-Saharan Africa, but this rangeland-based lifestyle is under threat. As a consequence a study was conducted in the Middle Awash Valley of Ethiopia with the main objectives of assessing and comparing the broad perceptions of two pastoral groups (the Oromo ethnic group living in Kereyu-Fantale and the Afar ethnic group living in Awash-Fantale) on the usage of the existing rangeland resources, and their views on constraints and possible solutions. Data were collected from 90 Oromo and 55 Afar households. Despite the difference in ethnicity both of these groups share common problems. They derive their main income from the sale of animals and animal products, but with the difference that milk products rank first in the case of the Afar and last in the case of the Oromo. Both pastoral groups depend heavily on native grasses for animal feed and to a lesser extent on woody plants as a source of browse. The majority of respondents were of the opinion that the condition of the rangelands is poor, mainly due to overgrazing, droughts and increases in the human population. Availability of water is also regarded as a problem, mainly by the Oromo. Migration is the first measure taken to solve shortages of livestock feed, but many of the pastoralists replied that migration is an undesirable practise which is mostly done out of necessity. Because of the limited resources most respondents of both groups still prefer communal land tenure where resources are shared. It is concluded that the problems facing the pastoralists in the Middle Awash Valley have been created over many years and the solutions will also require time. With the current approach of the communal grazing systems, sustainable utilisation of the rangeland ecosystem is not possible. Solutions to the poor condition of the existing rangelands will require a definite commitment and full participation not only of the pastoralists, but also of

  5. Adapting livestock management to spatio-temporal heterogeneity in semi-arid rangelands.

    PubMed

    Jakoby, O; Quaas, M F; Baumgärtner, S; Frank, K

    2015-10-01

    Management strategies in rotational grazing systems differ in their level of complexity and adaptivity. Different components of such grazing strategies are expected to allow for adaptation to environmental heterogeneities in space and time. However, most models investigating general principles of rangeland management strategies neglect spatio-temporal system properties including seasonality and spatial heterogeneity of environmental variables. We developed an ecological-economic rangeland model that combines a spatially explicit farm structure with intra-annual time steps. This allows investigating different management components in rotational grazing systems (including stocking and rotation rules) and evaluating their effect on the ecological and economic states of semi-arid grazing systems. Our results show that adaptive stocking is less sensitive to overstocking compared to a constant stocking strategy. Furthermore, the rotation rule becomes important only at stocking numbers that maximize expected income. Altogether, the best of the tested strategies is adaptive stocking combined with a rotation that adapts to both spatial forage availability and seasonality. This management strategy maximises mean income and at the same time maintains the rangeland in a viable condition. However, we could also show that inappropriate adaptation that neglects seasonality even leads to deterioration. Rangelands characterised by higher inter-annual climate variability show a higher risk of income losses under a non-adaptive stocking rule, and non-adaptive rotation is least able to buffer increasing climate variability. Overall, all important system properties including seasonality and spatial heterogeneity of available resources need to be considered when designing an appropriate rangeland management system. Resulting adaptive rotational grazing strategies can be valuable for improving management and mitigating income risks. PMID:26241933

  6. Effects of Management on Soil Carbon Pools in California Rangeland Ecosystems

    NASA Astrophysics Data System (ADS)

    Silver, W. L.; Ryals, R.; Lewis, D. J.; Creque, J.; Wacker, M.; Larson, S.

    2008-12-01

    Rangeland ecosystems managed for livestock production represent the largest land-use footprint globally, covering more than one-quarter of the world's land surface (Asner et al. 2004). In California, rangelands cover an estimated 17 million hectares or approximately 40% of the land area (FRAP 2003). These ecosystems have considerable potential to sequester carbon (C) in soil and offset greenhouse gas emissions through changes in land management practices. Climate policies and C markets may provide incentives for rangeland managers to pursue strategies that optimize soil C storage, yet we lack a thorough understanding of the effects of management on soil C pools in rangelands over time and space. We sampled soil C pools on rangelands in a 260 km2 region of Marin and Sonoma counties to determine if patterns in soil C storage exist with management. Replicate soil samples were collected from 35 fields that spanned the dominant soil orders, plant communities, and management practices in the region while controlling for slope and bioclimatic zone (n = 1050). Management practices included organic amendments, intensive (dairy) and extensive (other) grazing practices, and subsoiling. Soil C pools ranged from approximately 50 to 140 Mg C ha-1 to 1 m depth, with a mean of 99 ± 22 (sd) Mg C ha-1. Differences among sites were due primarily to C concentrations, which exhibited a much larger coefficient of variation than bulk density at all depths. There were no statistically significant differences among the dominant soil orders. Subsoiling appeared to significantly increase soil C content in the top 50 cm, even though subsoiling had only occurred for the first time the previous Nov. Organic amendments also appeared to greatly increase soil C pools, and was the dominant factor that distinguished soil C pools in intensive and extensive land uses. Our results indicate that management has the potential to significantly increase soil C pools. Future research will determine the

  7. Ecological site classification of semiarid rangelands: Synergistic use of Landsat and Hyperion imagery

    NASA Astrophysics Data System (ADS)

    Blanco, Paula D.; del Valle, Héctor F.; Bouza, Pablo J.; Metternicht, Graciela I.; Hardtke, Leonardo A.

    2014-06-01

    Ecological sites are the basic entity used in rangeland health assessment. This study evaluates the synergistic use of multi- and hyper-spectral satellite imagery for sub-pixel classification of ecological sites in semiarid rangelands. Hyperion and Landsat enhanced thematic mapper (ETM) data are included in a two-step procedure to mapping ecological sites in Patagonian rangelands of Argentina. Firstly, mixture tuned matched filtering and logistic regression analyses are used for Hyperion data processing to obtain ecological site probability images in the area covered by hyperspectral imagery. Secondly, artificial neural networks are applied to model the relationships between the spectral response patterns of Landsat and the probability images from Hyperion, and used to map ecological sites over the entire study area. Overall classification accuracy was 81% (kappa = 0.77) with relatively high accuracies for all ecological sites demonstrating that their spectral signatures are sufficiently distinct to be detectable. Better accuracies were obtained for shrub steppes with desert pavement (producer's and user's accuracies of 89% and 84%, respectively), and shrub-grass steppes associated to tertiary calcareous outcrops (producer's and user's accuracies of 100% and 86%, respectively), while poorer accuracies resulted for shrub-grass steppes on old alluvial plains (producer's and user's accuracies of 75% and 56%, respectively). Fuzzy maps of ecological sites as presented in this research can provide rangeland managers with a tool to stratify the landscape and organize ecological information for rangeland health assessment and monitoring, prioritizing and selecting appropriate management actions, and promoting the recovery of areas degraded in these environments.

  8. Recovering Radioactive Materials with ORSP Team

    ScienceCinema

    LANL

    2009-09-01

    The National Nuclear Security Administration sponsors a program, executed by Los Alamos National Laboratory, to recover radioisotopes used by industry and academia and no longer needed. Called the "Offsite Source Recovery Program (OSRP), it has recovered more than 16,000 orphan sources as of 2008.

  9. Variation of terpenes in milk and cultured cream from Norwegian alpine rangeland-fed and in-door fed cows.

    PubMed

    Borge, Grethe Iren A; Sandberg, Ellen; Øyaas, Jorun; Abrahamsen, Roger K

    2016-05-15

    The terpene content of milk and cream made from milk obtained from cows fed indoors, and by early or late grazing, in alpine rangeland farms in Norway, were analysed for three consecutive years. The main terpenes identified and semi-quantified were the monoterpenes β-pinene, α-pinene, α-thujene, camphene, sabinene, δ-3-carene, d-limonene, γ-terpinene, camphor, β-citronellene, and the sesquiterpene β-caryophyllene. The average total terpene content increased five times during the alpine rangeland feeding period. The terpenes α-thujene, sabinene, γ-terpinene and β-citronellene were only detected in milk and cultured cream from the alpine rangeland feeding period and not in samples from the indoors feeding period. These four terpenes could be used, as indicators, to show that milk and cultured cream originate from the alpine rangeland feeding period. The terpenes did not influence the sensorial quality of the milk or the cultured cream. PMID:26775961

  10. Employing UAVs to Acquire Detailed Vegetation and Bare Ground Data for Assessing Rangeland Health

    NASA Astrophysics Data System (ADS)

    Rango, A.; Laliberte, A.; Herrick, J. E.; Winters, C.

    2007-12-01

    Because of its value as a historical record (extending back to the mid 1930s), aerial photography is an important tool used in many rangeland studies. However, these historical photos are not very useful for detailed analysis of rangeland health because of inadequate spatial resolution and scheduling limitations. These issues are now being resolved by using Unmanned Aerial Vehicles (UAVs) over rangeland study areas. Spatial resolution improvements have been rapid in the last 10 years from the QuickBird satellite through improved aerial photography to the new UAV coverage and have utilized improved sensors and the more simplistic approach of low altitude flights. Our rangeland health experiments have shown that the low altitude UAV digital photography is preferred by rangeland scientists because it allows, for the first time, their identification of vegetation and land surface patterns and patches, gap sizes, bare soil percentages, and vegetation type. This hyperspatial imagery (imagery with a resolution finer than the object of interest) is obtained at about 5cm resolution by flying at an altitude of 150m above the surface of the Jornada Experimental Range in southern New Mexico. Additionally, the UAV provides improved temporal flexibility, such as flights immediately following fires, floods, and other catastrophic disturbances, because the flight capability is located near the study area and the vehicles are under the direct control of the users, eliminating the additional steps associated with budgets and contracts. There are significant challenges to improve the data to make them useful for operational agencies, namely, image distortion with inexpensive, consumer grade digital cameras, difficulty in detecting sufficient ground control points in small scenes (152m by 114m), accuracy of exterior UAV information on X,Y, Z, roll, pitch, and heading, the sheer number of images collected, and developing reliable relationships with ground-based data across a broad

  11. Sea Level Variability of the Argentine Basin From 25 to 5000 Days

    NASA Astrophysics Data System (ADS)

    Fu, L.

    2006-12-01

    While the mean sea level of the global oceans has been rising since the modern recording by tide gauges began over 100 years ago, the details of the spatial variability of sea level are not known until the advent of precision measurement from satellite altimeters slightly more than a decade ago. This new knowledge of spatial variability not only underscores the issue of sampling errors from sparsely located tide gauges; it also reveals the richness of ocean dynamics in affecting sea level changes. An example is given on the sea level of the Argentine Basin of the South Atlantic. The 13 plus years' (5000 days) worth of altimetry data from TOPEX/Poseidon, Jason, and ERS revealed a trend of rising sea level at the center of the basin at a rate greater than 1 cm/year, with strong seasonal-to-interannual variability. The part of sea level variability caused by the change in the heat storage in the upper ocean was estimated from in-situ observations. After subtracting this "thermosteric sea level" from the altimeter observations, the residual sea levels showed an isolated pool of rising trend (greater than 1 cm/year) over the Zapiola Rise (a sediment ridge centered on 45 S, 45 W), suggesting that the barotropic gyre of the Zapiola Anticyclone was spinning up over the past 13 years. In the mean time, the eddy kinetic energy in the surrounding regions also showed significant rising trends, suggesting possible relationship between the Zapiola Anticyclone and the surrounding eddy field on decadal time scales. There is also evidence for energy exchange between eddies and barotropic gyre-scale waves with periods close to 25 days in the Argentine Basin. The apparent interactions among a wide range of scales make the Argentine Basin an interesting and challenging region for theoretical and modeling studies to sort out the mechanisms of the interactions.

  12. Hydrological cycles and trends in the NW Argentine Andes since 1940

    NASA Astrophysics Data System (ADS)

    Castino, Fabiana; Bookhagen, Bodo; Strecker, Manfred

    2016-04-01

    Strong spatiotemporal variability characterizes the hydrometeorological pattern in the NW Argentine Andes, draining parts of the most populated and economically important areas of South America. During the summer monsoon season (DJF), the eastern flanks of the central Andes are characterized by deep convection, exposing them to extreme hydrometeorological events. These often result in floods and landslides with disastrous effects on the local populations. Here, we analyze river discharge to explore long-term hydrological variability in NW Argentine Andes and the linked climate controlling processes. We rely on 13 daily river discharge time series relevant to drainage basins spanning several size orders (102-104 km2) starting in 1914 and define different hydro-climate indices both for the mean and the extreme hydrological events. We apply quantile regression to investigate long-term trends and spectral analysis associated with cross-correlation with SST-based climate indices to identify links to large-scale climate variability modes. River discharge presents a pronounced and coherent variability signal in South America, particularly for wide drainage basins, such as the Amazon and Paraná/La Plata rivers, strongly associated to Pacific and Atlantic Oceans Sea Surface Temperature (SST) anomalies (i.e. ENSO, PDO, AMO). Our analysis evidences that in the NW Argentine Andes, mean discharge values are characterized by statistically significant, mostly positive, long-term trends since 1940, whereas the extreme events present a more non-unidirectional trend pattern. Also, coherent multi-annual to multi-decadal cycles characterizing the discharge pattern have been identified, suggesting that processes linked to SST anomaly-modes strongly control the hydrometeorology variability in the NW Argentina Andes.

  13. Hantavirus reservoir Oligoryzomys longicaudatus spatial distribution sensitivity to climate change scenarios in Argentine Patagonia

    PubMed Central

    Carbajo, Aníbal E; Vera, Carolina; González, Paula LM

    2009-01-01

    Background Oligoryzomys longicaudatus (colilargo) is the rodent responsible for hantavirus pulmonary syndrome (HPS) in Argentine Patagonia. In past decades (1967–1998), trends of precipitation reduction and surface air temperature increase have been observed in western Patagonia. We explore how the potential distribution of the hantavirus reservoir would change under different climate change scenarios based on the observed trends. Methods Four scenarios of potential climate change were constructed using temperature and precipitation changes observed in Argentine Patagonia between 1967 and 1998: Scenario 1 assumed no change in precipitation but a temperature trend as observed; scenario 2 assumed no changes in temperature but a precipitation trend as observed; Scenario 3 included changes in both temperature and precipitation trends as observed; Scenario 4 assumed changes in both temperature and precipitation trends as observed but doubled. We used a validated spatial distribution model of O. longicaudatus as a function of temperature and precipitation. From the model probability of the rodent presence was calculated for each scenario. Results If changes in precipitation follow previous trends, the probability of the colilargo presence would fall in the HPS transmission zone of northern Patagonia. If temperature and precipitation trends remain at current levels for 60 years or double in the future 30 years, the probability of the rodent presence and the associated total area of potential distribution would diminish throughout Patagonia; the areas of potential distribution for colilargos would shift eastwards. These results suggest that future changes in Patagonia climate may lower transmission risk through a reduction in the potential distribution of the rodent reservoir. Conclusion According to our model the rates of temperature and precipitation changes observed between 1967 and 1998 may produce significant changes in the rodent distribution in an equivalent

  14. ``You are what you eat'': Diet modifies cuticular hydrocarbons and nestmate recognition in the Argentine ant, Linepithema humile

    NASA Astrophysics Data System (ADS)

    Liang, D.; Silverman, J.

    2000-10-01

    Nestmate recognition plays a key role in the behavior and evolution of social insects. We demonstrated that hydrocarbons are the chemical cues used in Argentine ant, Linepithema humile, nestmate recognition, and that these hydrocarbons can be acquired from insect prey. Consequently, Argentine ant cuticular hydrocarbon patterns reveal the same hydrocarbons present in their diet. Diet alters both the recognition cues present on the cuticular surface and the response of nestmates to this new colony odor, resulting in aggression between former nestmates reared on different insect prey.

  15. "You are what you eat": diet modifies cuticular hydrocarbons and nestmate recognition in the Argentine ant, Linepithema humile.

    PubMed

    Liang, D; Silverman, J

    2000-09-01

    Nestmate recognition plays a key role in the behavior and evolution of social insects. We demonstrated that hydrocarbons are the chemical cues used in Argentine ant, Linepithema humile, nestmate recognition, and that these hydrocarbons can be acquired from insect prey. Consequently, Argentine ant cuticular hydrocarbon patterns reveal the same hydrocarbons present in their diet. Diet alters both the recognition cues present on the cuticular surface and the response of nestmates to this new colony odor, resulting in aggression between former nestmates reared on different insect prey. PMID:11091966

  16. Equity during an economic crisis: financing of the Argentine health system.

    PubMed

    Cavagnero, Eleonora; Bilger, Marcel

    2010-07-01

    This article analyses the redistributive effect caused by health financing and the distribution of healthcare utilization in Argentina before and during the severe 2001/2002 economic crisis. Both dramatically changed during this period: the redistributive effect became much more positive and utilization shifted from pro-poor to pro-rich. This clearly demonstrates that when utilization is contingent on financing, changes can occur rapidly; and that an integrated approach is required when monitoring equity. From a policy perspective, the Argentine health system appears vulnerable to economic downturns mainly due to high reliance on out-of-pocket payments and the strong link between health insurance and employment. PMID:20452070

  17. Automated monitoring of recovered water quality

    NASA Technical Reports Server (NTRS)

    Misselhorn, J. E.; Hartung, W. H.; Witz, S. W.

    1974-01-01

    Laboratory prototype water quality monitoring system provides automatic system for online monitoring of chemical, physical, and bacteriological properties of recovered water and for signaling malfunction in water recovery system. Monitor incorporates whenever possible commercially available sensors suitably modified.

  18. Metallurgical examination of recovered copper jet particles

    SciTech Connect

    Lassila, D.H.; Nikkel, D.J. Jr.; Kershaw, R.P.; Walters, W.P.

    1995-11-30

    A shaped charge (81 mm, 42{degrees}, OFHC copper cone) was fired into a ``soft` recovery bunker to allow metallurgical examination of recovered jet particles and the slug. The initial weight of the copper liner was 245 gm, of which 184 gm was recovered. The number of jet particles recovered was 37 (approximately 63% of the particles formed by the charge). Extensive metallurgical analyses were performed on the recovered slug and jet particles. The microstructural features associated with voids, e.g. dendritic grain growth, clearly indicate that the regions in the vicinity of the centerline of the slug and jet particles were melted. In this work we present calculations of jet temperature as a function of constitutive behavior. In order to predict melt in the center region of the jet we find it necessary to scale flow stress with a pressure dependent shear modulus.

  19. Recovering recyclable materials from shredder residue

    NASA Astrophysics Data System (ADS)

    Jody, Bassam J.; Daniels, Edward J.; Bonsignore, Patrick V.; Brockmeier, Norman F.

    1994-02-01

    Each year, about 11 million tons of metals are recovered in the United States from about 10 million discarded automobiles. The recovered metals account for about 75 percent of the total weight of the discarded vehicles. The balance of the material, known as shredder residue, amounts to about three million tons annually and is currently landfilled. The residue contains a diversity of potentially recyclable materials, including polyurethane foams, iron oxides, and certain thermoplastics. This article discusses a process under development at Argonne National Laboratory to separate and recover the recyclable materials from this waste stream. The process consists essentially of two stages. First, a physical separation is used to recover the foams and the metal oxides, followed by a chemical process to extract certain thermoplastics. The status of the technology and the process economics are reviewed here.

  20. METHOD FOR RECOVERING URANIUM FROM OILS

    DOEpatents

    Gooch, L.H.

    1959-07-14

    A method is presented for recovering uranium from hydrocarbon oils, wherein the uranium is principally present as UF/sub 4/. According to the invention, substantially complete removal of the uranium from the hydrocarbon oil may be effected by intimately mixing one part of acetone to about 2 to 12 parts of the hydrocarbon oil containing uranium and separating the resulting cake of uranium from the resulting mixture. The uranium in the cake may be readily recovered by burning to the oxide.

  1. The value of forage measurement information in rangeland management. [implementation of satellite data in range management

    NASA Technical Reports Server (NTRS)

    Lietzke, K. R.

    1975-01-01

    An economic model and simulation are developed to estimate the potential social benefit arising from the use of alternative measurement systems in rangeland management. In order to estimate these benefits, it was necessary to model three separate systems: the range environment, the rangeland manager, and the information system which links the two. The rancher's decision-making behavior is modeled according to sound economic principles. Results indicate substantial potential benefits, particularly when used in assisting management of government-operated ranges; possible annual benefits in this area range from $20 to $46 million, depending upon the system capabilities assumed. Possible annual benefit in privately-managed stocker operations range from $2.8 to $49.5 million, depending upon where actual rancher capabilities lie and what system capabilities are assumed.

  2. Mapping soils, crops, and rangelands by machine analysis of multitemporal ERTS-1 data. [Kansas and Texas

    NASA Technical Reports Server (NTRS)

    Baumgardner, M. F.; Henderson, J. A., Jr.

    1974-01-01

    ERTS-1 data, obtained during the period 25 August 1972 to 5 September 1973 over a range of test sites in the Central United States, have been used for identifying and mapping differences in soil patterns, species and conditions of cultivated crops, and conditions of rangelands. Multispectral scanner data from multiple ERTS passes over certain test sites have provided the opportunity to study temporal changes in the scene. Multispectral classifications delineating soils boundaries in different test sites compared well with existing soil association maps prepared by conventional means. Spectral analysis of ERTS data was used to identify, maps, and make areal measurements of wheat in western Kansas. Multispectral analysis of ERTS-1 data provided patterns in rangelands which can be related to soils differences, range management practices, and the extent of infestation of grasslands by mesquite (prosopis fuliflora) and juniper (juniperus spp.).

  3. A LANDSAT study of ephemeral and perennial rangeland vegetation and soils

    NASA Technical Reports Server (NTRS)

    Bentley, R. G., Jr. (Principal Investigator); Salmon-Drexler, B. C.; Bonner, W. J.; Vincent, R. K.

    1976-01-01

    The author has identified the following significant results. Several methods of computer processing were applied to LANDSAT data for mapping vegetation characteristics of perennial rangeland in Montana and ephemeral rangeland in Arizona. The choice of optimal processing technique was dependent on prescribed mapping and site condition. Single channel level slicing and ratioing of channels were used for simple enhancement. Predictive models for mapping percent vegetation cover based on data from field spectra and LANDSAT data were generated by multiple linear regression of six unique LANDSAT spectral ratios. Ratio gating logic and maximum likelihood classification were applied successfully to recognize plant communities in Montana. Maximum likelihood classification did little to improve recognition of terrain features when compared to a single channel density slice in sparsely vegetated Arizona. LANDSAT was found to be more sensitive to differences between plant communities based on percentages of vigorous vegetation than to actual physical or spectral differences among plant species.

  4. Assessment of rangeland ecosystem conditions, Salt Creek watershed and Dugout Ranch, southeastern Utah

    USGS Publications Warehouse

    Bowker, M.A.; Miller, M.E.; Belote, R.T.

    2012-01-01

    Increasingly, dry rangelands are being valued for multiple services beyond their traditional value as a forage production system. Additional ecosystem services include the potential to store carbon in the soil and plant biomass. In addition, dust emissions from rangelands might be considered an ecosystem detriment, the opposite of an ecosystem service. Dust emitted may have far-reaching impacts, for example, reduction of local air quality, as well as altering regional water supplies through effects on snowpack. Using an extensive rangeland monitoring dataset in the greater Canyonlands region (Utah, USA), we developed a method to estimate indices of the provisioning of three ecosystem services (forage production, dust retention, C storage) and one ecosystem property (nativeness), taking into account both ecosystem type and alternative states within that ecosystem type. We also integrated these four indices into a multifunctionality index. Comparing the currently ungrazed Canyonlands National Park watersheds to the adjacent Dugout Ranch pastures, we found clearly higher multifunctionality was attained in the Park, and that this was primarily driven by greater C-storage and better dust retention. It is unlikely to maximize all benefits and minimize all detriments at the same time. Some goods and services may have synergistic interactions; for example, managing for carbon storage will increase plant and biocrust cover likely lowering dust emission. Likewise, some may have antagonistic interactions. For instance, if carbon is consumed as biomass for livestock production, then carbon storage may be reduced. Ultimately our goal should be to quantify the monetary consequences of specific land use practices for multiple ecosystem services and determine the best land use and adaptive management practices for attaining multiple ecosystem services, minimizing economic detriments, and maximizing economic benefits from multi-commodity rangelands. Our technique is the first step

  5. Linking ecosystem services with state-and-transition models to evaluate rangeland management decisions

    NASA Astrophysics Data System (ADS)

    Lohani, S.; Heilman, P.; deSteiguer, J. E.; Guertin, D. P.; Wissler, C.; McClaran, M. P.

    2014-12-01

    Quantifying ecosystem services is a crucial topic for land management decision making. However, market prices are usually not able to capture all the ecosystem services and disservices. Ecosystem services from rangelands, that cover 70% of the world's land area, are even less well-understood since knowledge of rangelands is limited. This study generated a management framework for rangelands that uses remote sensing to generate state and transition models (STMs) for a large area and a linear programming (LP) model that uses ecosystem services to evaluate natural and/or management induced transitions as described in the STM. The LP optimization model determines the best management plan for a plot of semi-arid land in the Empire Ranch in southeastern Arizona. The model allocated land among management activities (do nothing, grazing, fire, and brush removal) to optimize net benefits and determined the impact of monetizing environmental services and disservices on net benefits, acreage allocation and production output. The ecosystem services under study were forage production (AUM/ac/yr), sediment (lbs/ac/yr), water runoff (inches/yr), soil loss (lbs/ac/yr) and recreation (thousands of number of visitors/ac/yr). The optimization model was run for three different scenarios - private rancher, public rancher including environmental services and excluding disservices, and public rancher including both services and disservices. The net benefit was the highest for the public rancher excluding the disservices. A result from the study is a constrained optimization model that incorporates ecosystem services to analyze investments on conservation and management activities. Rangeland managers can use this model to understand and explain, not prescribe, the tradeoffs of management investments.

  6. Pastoralists' responses to variation of rangeland resources in time and space.

    PubMed

    McAllister, Ryan R J; Gordon, Iain J; Janssen, Marco A; Abel, Nick

    2006-04-01

    We explore the response of pastoralists to rangeland resource variation in time and space, focusing on regions where high variation makes it unlikely that an economically viable herd can be maintained on a single management unit. In such regions, the need to move stock to find forage in at least some years has led to the evolution of nomadism and transhumance, and reciprocal grazing agreements among the holders of common-property rangeland. The role of such informal institutions in buffering resource variation is well documented in some Asian and African rangelands, but in societies with formally established private-property regimes, where we focus, such institutions have received little attention. We examine agistment networks, which play an important role in buffering resource variation in modern-day Australia. Agistment is a commercial arrangement between pastoralists who have less forage than they believe they require and pastoralists who believe they have more. Agistment facilitates the movement of livestock via a network based largely on trust. We are concerned exclusively with the link between the characteristics of biophysical variation and human aspects of agistment networks, and we developed a model to test the hypothesis that such a link could exist. Our model builds on game theory literature, which explains cooperation between strangers based on the ability of players to learn whom they can trust. Our game is played on a highly stylized landscape that allows us to control and isolate the degree of spatial variation and spatial covariation. We found that agistment networks are more effective where spatial variation in resource availability is high, and generally more effective when spatial covariation is low. Policy design that seeks to work with existing social networks in rangelands has potential, but this potential varies depending on localized characteristics of the biophysical variability. PMID:16711045

  7. Nationwide forestry applications program: Procedure 1 applicability to rangeland classification. [Weld County, Colorado

    NASA Technical Reports Server (NTRS)

    Reeves, C. A. (Principal Investigator)

    1978-01-01

    The author has identified the following significant results. An assumption that short prairie grass and salt grass could be differentiated on aircraft photographs was inaccurate for the Weld County site. However, rangeland could be differentiated using procedure 1 from LACIE. Estimates derived from either random or systematic sampling were satisfactory. Level 1 features were separated and mapped, and proportions were estimated with accompanying confidence statements.

  8. Rangeland monitoring reveals long-term plant responses to precipitation and grazing at the landscape scale

    USGS Publications Warehouse

    Munson, Seth M.; Duniway, Michael C.; Johanson, Jamin K.

    2015-01-01

    Managers of rangeland ecosystems require methods to track the condition of natural resources over large areas and long periods of time as they confront climate change and land use intensification. We demonstrate how rangeland monitoring results can be synthesized using ecological site concepts to understand how climate, site factors, and management actions affect long-term vegetation dynamics at the landscape-scale. Forty-six years of rangeland monitoring conducted by the Bureau of Land Management (BLM) on the Colorado Plateau reveals variable responses of plant species cover to cool-season precipitation, land type (ecological site groups), and grazing intensity. Dominant C3 perennial grasses (Achnatherum hymenoides, Hesperostipa comata), which are essential to support wildlife and livestock on the Colorado Plateau, had responses to cool-season precipitation that were at least twice as large as the dominant C4 perennial grass (Pleuraphis jamesii) and woody vegetation. However, these C3 perennial grass responses to precipitation were reduced by nearly one-third on grassland ecological sites with fine- rather than coarse-textured soils, and there were no detectable C3 perennial grass responses to precipitation on ecological sites dominated by a dense-growing shrub, Coleogyne ramosissima. Heavy grazing intensity further reduced the responses of C3 perennial grasses to cool-season precipitation on ecological sites with coarse-textured soils and surprisingly reduced the responses of shrubs as well. By using ecological site groups to assess rangeland condition, we were able to improve our understanding of the long-term relationships between vegetation change and climate, land use, and site characteristics, which has important implications for developing landscape-scale monitoring strategies.

  9. The use of low-resolution satellite image data for rangeland monitoring

    USGS Publications Warehouse

    Holm, Thomas M.; Draeger, William C.; Williams, Patrick T.; Buzzard, Robert F.

    1985-01-01

    The U.S. Geological Survey's Earth Resources Observation Systems (EROS) Data Center and the Bureau of Indian Affairs (BIA) jointly evaluated the used of Advanced Very High Resolution Radiometer (AVHRR) images for the calculate of normalized difference data as a green biomass indicator in an arid rangeland environment. The normalized difference data were compared to corresponding field-collected herbage data, and were used in a geographic information system to provide range management information.

  10. Evaluating Current and Future Rangeland Health in the Great Basin Ecoregion Using NASA Earth Observing Systems

    NASA Astrophysics Data System (ADS)

    Essoudry, E.; Wilson, K.; Ely, J.; Patadia, N.; Zajic, B.; Torres-Perez, J. L.; Schmidt, C.

    2014-12-01

    The Great Basin ecoregion in the western United States represents one of the last large expanses of wild lands in the nation and is currently facing significant challenges due to human impacts, drought, invasive species encroachment such as cheatgrass, and climate change. Rangelands in the Great Basin are of important ecological and economic significance for the United States; however, 40% of public rangelands fail to meet required health standards set by the Bureau of Land Management (BLM). This project provided a set of assessment tools for researchers and land managers that integrate remotely-sensed and in situ datasets to quantify and mitigate threats to public lands in the Great Basin ecoregion. The study area, which accounts for 20% of the total Great Basin ecoregion, was analyzed using 30 m resolution data from Landsat 8. Present conditions were evaluated from vegetation indices, landscape features, hydrological processes, and atmospheric conditions derived from the remotely-sensed data and validated with available in situ ground survey data, provided by the BLM. Rangeland health metrics were developed and landscape change drivers were identified. Subsequently, projected climate conditions derived from the Coupled Model Intercomparison Project (CMIP5) were used to forecast the impact of changing climatic conditions within the study area according to the RCP4.5 and RCP8.5 projections. These forecasted conditions were used in the Maximum Entropy Model (MaxEnt) to predict areas at risk for rangeland degradation on 30 year intervals for 2040, 2070, and 2100. Finally, vegetation health risk maps were provided to the project partners to aid in future land management decisions in the Great Basin ecoregion. These tools provide a low cost solution to assess landscape conditions, provide partners with a metric to identify potential problematic areas, and mitigate serious threats to the ecosystems.

  11. Remote camera-trap methods and analyses reveal impacts of rangeland management on Namibian carnivore communities

    USGS Publications Warehouse

    Kauffman, M.J.; Sanjayan, M.; Lowenstein, J.; Nelson, A.; Jeo, R.M.; Crooks, K.R.

    2007-01-01

    Assessing the abundance and distribution of mammalian carnivores is vital for understanding their ecology and providing for their long-term conservation. Because of the difficulty of trapping and handling carnivores many studies have relied on abundance indices that may not accurately reflect real abundance and distribution patterns. We developed statistical analyses that detect spatial correlation in visitation data from combined scent station and camera-trap surveys, and we illustrate how to use such data to make inferences about changes in carnivore assemblages. As a case study we compared the carnivore communities of adjacent communal and freehold rangelands in central Namibia. We used an index of overdispersion to test for repeat visits to individual camera-trap scent stations and a bootstrap simulation to test for correlations in visits to camera neighbourhoods. After distilling our presence-absence data to the most defensible spatial scale, we assessed overall carnivore visitation using logistic regression. Our analyses confirmed the expected pattern of a depauparate fauna on the communal rangelands compared to the freehold rangelands. Additionally, the species that were not detected on communal sites were the larger-bodied carnivores. By modelling these rare visits as a Poisson process we illustrate a method of inferring whether or not such patterns are because of local extinction of species or are simply a result of low sample effort. Our Namibian case study indicates that these field methods and analyses can detect meaningful differences in the carnivore communities brought about by anthropogenic influences. ?? 2007 FFI.

  12. Ecosystem performance monitoring of rangelands by integrating modeling and remote sensing

    USGS Publications Warehouse

    Wylie, Bruce K.; Boyte, Stephen P.; Major, Donald J.

    2012-01-01

    Monitoring rangeland ecosystem dynamics, production, and performance is valuable for researchers and land managers. However, ecosystem monitoring studies can be difficult to interpret and apply appropriately if management decisions and disturbances are inseparable from the ecosystem's climate signal. This study separates seasonal weather influences from influences caused by disturbances and management decisions, making interannual time-series analysis more consistent and interpretable. We compared the actual ecosystem performance (AEP) of five rangeland vegetation types in the Owyhee Uplands for 9 yr to their expected ecosystem performance (EEP). Integrated growing season Normalized Difference Vegetation Index data for each of the nine growing seasons served as a proxy for annual AEP. Regression-tree models used long-term site potential, seasonal weather, and land cover data sets to generate annual EEP, an estimate of ecosystem performance incorporating annual weather variations. The difference between AEP and EEP provided a performance measure for each pixel in the study area. Ecosystem performance anomalies occurred when the ecosystem performed significantly better or worse than the model predicted. About 14% of the Owyhee Uplands showed a trend of significant underperformance or overperformance (P<0.10). Land managers can use results from weather-based rangeland ecosystem performance models to help support adaptive management strategies.

  13. Estimating flow concentration and sediment redistribution in shrub-dominated rangeland communities

    NASA Astrophysics Data System (ADS)

    Nouwakpo, S. K.; Weltz, M.; McGwire, K. C.; Rossi, C.

    2014-12-01

    In arid and semi-arid rangelands where vegetation is typically sparse, a synergistic relationship is assumed to exist between spatial distribution of plants and hydrologic and erosion processes. It is believed that areas underneath plant canopy have been conditioned to act as sediment, nutrients and water sinks whereas interspaces evolve into flow concentration pathways acting as source areas. This vegetation - hydrology feedback mechanism is part of a broader Vegetation Driven Spatial Heterogeneity (VDSH) concept that has been traditionally studied from a theoretical stand point but with little support from experimental data. In shrub-dominated rangeland communities, this VDSH concept implies that spatial distribution of vegetation can be used to model: (1) the level of hillslope dissection into concentrated flow and sheet flow areas and (2) the magnitude of sediment entrapment (deposition) expected from a given vegetation spatial arrangement. In this study, we developed a methodology to test these two hypotheses and derive practical equations for modeling purposes. From a series of rainfall / runoff experiments on naturally vegetated shrubland erosion plots, flow concentration and erosion / deposition processes were quantified using a combination of sediment yield data and high resolution microtopographic changes detected with advance 3D reconstruction technologies (lidar and photogrammetry). This study is expected to produce for the first time (1) predictive equations for spatial frequency of flow concentration pathways in shrub-dominated rangeland communities and (2) equations for sediment delivery ratio, a measure of the portion of eroded sediment that reaches the hillslope outlet as a function of vegetation spatial arrangement.

  14. Climate Change and Land Management in the Rangelands of Central Oregon

    NASA Astrophysics Data System (ADS)

    Creutzburg, Megan K.; Halofsky, Jessica E.; Halofsky, Joshua S.; Christopher, Treg A.

    2015-01-01

    Climate change, along with exotic species, disturbances, and land use change, will likely have major impacts on sagebrush steppe ecosystems in the western U.S. over the next century. To effectively manage sagebrush steppe landscapes for long-term goals, managers need information about the interacting impacts of climate change, disturbances and land management on vegetation condition. Using a climate-informed state-and-transition model, we evaluated the potential impacts of climate change on rangeland condition in central Oregon and the effectiveness of multiple management strategies. Under three scenarios of climate change, we projected widespread shifts in potential vegetation types over the twenty-first century, with declining sagebrush steppe and expanding salt desert shrub likely by the end of the century. Many extreme fire years occurred under all climate change scenarios, triggering rapid vegetation shifts. Increasing wildfire under climate change resulted in expansion of exotic grasses but also decreased juniper encroachment relative to projections without climate change. Restoration treatments in warm-dry sagebrush steppe were ineffective in containing exotic grass, but juniper treatments in cool-moist sagebrush steppe substantially reduced the rate of juniper encroachment, particularly when prioritized early in the century. Overall, climate-related shifts dominated future vegetation patterns, making management for improved rangeland condition more difficult. Our approach allows researchers and managers to examine long-term trends and uncertainty in rangeland vegetation condition and test the effectiveness of alternative management actions under projected climate change.

  15. Climate change and land management in the rangelands of central Oregon.

    PubMed

    Creutzburg, Megan K; Halofsky, Jessica E; Halofsky, Joshua S; Christopher, Treg A

    2015-01-01

    Climate change, along with exotic species, disturbances, and land use change, will likely have major impacts on sagebrush steppe ecosystems in the western U.S. over the next century. To effectively manage sagebrush steppe landscapes for long-term goals, managers need information about the interacting impacts of climate change, disturbances and land management on vegetation condition. Using a climate-informed state-and-transition model, we evaluated the potential impacts of climate change on rangeland condition in central Oregon and the effectiveness of multiple management strategies. Under three scenarios of climate change, we projected widespread shifts in potential vegetation types over the twenty-first century, with declining sagebrush steppe and expanding salt desert shrub likely by the end of the century. Many extreme fire years occurred under all climate change scenarios, triggering rapid vegetation shifts. Increasing wildfire under climate change resulted in expansion of exotic grasses but also decreased juniper encroachment relative to projections without climate change. Restoration treatments in warm-dry sagebrush steppe were ineffective in containing exotic grass, but juniper treatments in cool-moist sagebrush steppe substantially reduced the rate of juniper encroachment, particularly when prioritized early in the century. Overall, climate-related shifts dominated future vegetation patterns, making management for improved rangeland condition more difficult. Our approach allows researchers and managers to examine long-term trends and uncertainty in rangeland vegetation condition and test the effectiveness of alternative management actions under projected climate change. PMID:25216989

  16. Laboratory and Field Evaluations of Polyacrylamide Hydrogel Baits Against Argentine Ants (Hymenoptera: Formicidae).

    PubMed

    Rust, Michael K; Soeprono, Andrew; Wright, Sarajean; Greenberg, Les; Choe, Dong-Hwan; Boser, Christina L; Cory, Coleen; Hanna, Cause

    2015-06-01

    The development of effective baits to control the Argentine ant, Linepithema humile (Mayr), has been problematic because foragers prefer sweet liquids, while many toxicants are insoluble in water and liquid baits are generally difficult to deliver. The incorporation of thiamethoxam and sucrose solutions into a water-absorbing polyacrylamide hydrogel provides a unique and novel carrier and method of application for liquid baits. Formulations of thiamethoxam affected the size of the hydrogels, and sucrose solutions containing 0.0003% technical thiamethoxam provided hydrogels as large as those made with 25% sucrose solution or deionized water. Concentrations of thiamethoxam as low as 0.000075% in the hydrogels provided 50% kill of workers within 3 d in a laboratory setting. In small colony studies, baiting with 0.00015 and 0.000075% thiamethoxam hydrogels provided 100% mortality of workers and queens within 8 d. An enzyme-linked immunosorbent assay indicated that thiamethoxam was absorbed into the interior of the polyacrylamide matrix. The water loss rates of the hydrogels were dependent upon the relative humidity. Polyacrylamide hydrogels with >50% water loss were less attractive to ants. Field studies in highly infested areas indicated that concentrations of 0.0006 or 0.0018% thiamethoxam were more effective than 0.00015%. Hydrogels may provide a cost-effective alternative to providing aqueous baits to control Argentine ants. PMID:26470250

  17. Potential application of Northern Argentine propolis to control some phytopathogenic bacteria.

    PubMed

    Ordóñez, R M; Zampini, I C; Moreno, M I Nieva; Isla, M I

    2011-10-20

    The antimicrobial activity of samples of Northern Argentine propolis (Tucumán, Santiago del Estero and Chaco) against phytopathogenic bacteria was assessed and the most active samples were identified. Minimal inhibitory concentration (MIC) values were determined by agar macrodilution and broth microdilution assays. Strong antibacterial activity was detected against Erwinia carotovora spp carotovora CECT 225, Pseudomonas syringae pvar tomato CECT 126, Pseudomonas corrugata CECT 124 and Xanthomonas campestris pvar vesicatoria CECT 792. The most active propolis extract (Tucumán, T1) was selected to bioguide isolation and identified for antimicrobial compound (2',4'-dihydroxychalcone). The antibacterial chalcone was more active than the propolis ethanolic extract (MIC values of 0.5-1 μg ml(-1) and 9.5-15 μg ml(-1), respectively). Phytotoxicity assays were realized and the propolis extracts did not retard germination of lettuce seeds or the growth of onion roots. Propolis solutions applied as sprays on tomato fruits infected with P. syringae reduced the severity of disease. Application of the Argentine propolis extracts diluted with water may be promising for the management of post harvest diseases of fruits. PMID:21237629

  18. Portrayals of character smoking and drinking in Argentine-, Mexican- and US-produced films.

    PubMed

    Kollath-Cattano, Christy; Abad-Vivero, Erika N; Mejia, Raul; Perez-Hernandez, Rosaura; Sargent, James D; Thrasher, James F

    2016-09-01

    The aim of this study was to assess film character portrayals of tobacco and alcohol use in US and nationally-produced films that were popular in Argentina and Mexico from 2004-2012. We performed a content analysis of these films (n=82 Argentine, 91 Mexican, and 908 US films, respectively). Chi-squares and t-tests were used to compare characteristics of characters who smoked or drank by country of movie production. Then data from all countries were pooled, and generalized estimating equation (GEE) models were used to determine independent correlates of character smoking or drinking. There were 480 major characters for Argentine-, 364 for Mexican-, and 4962 for US-produced films. Smoking prevalence among movie characters was similar to population smoking prevalence in Mexico (21%) and Argentina (26%), but about half in the US (11%), where movie product placements are restricted. Movie smoking declined over the period in all three countries. Movie alcohol prevalence was 40-50% across all countries and did not change with time. Demographic predictors of character smoking included: being male, 18 and older, having negative character valence. Movie smoking was not associated with lower SES. Predictors of character drinking included: being age 18 and older and positive character valence. Smoking and drinking predicted each other, illicit drug use, and higher scores for other risk behaviors. This suggests that policy development in Mexico and Argentina may be necessary to reduce the amount of character tobacco and alcohol use in films. PMID:27404576

  19. [Consensus guidelines for respiratory endoscopy issued by the Argentine Society of Bronchoesophagology].

    PubMed

    Quadrelli, S; Grynblat, P; Defranchi, H; Downey, D; de la Canal, A; Perrone, R; Schiaffini Mauro, A

    1998-04-01

    The international consensus is that guidelines for respiratory endoscopy are inadequate, regarding such issues as institutional requirements, benefits, risks and limitations of the procedure, training programs and accreditation, with the result that the way or performing endoscopy varies according to how an operator was trained. The absence of precise recommendations means that practice is highly diverse and inappropriate use of the procedure has increased. The Argentine Consensus Group for Normalization of Respiratory Endoscopy was created in 1995 to unify criteria for several aspects of endoscopic practice. The official recommendations of the Group and of the Argentine Society of Bronchoesophagology define the indications (diagnostic, therapeutic and investigative) and contraindications (absolute, relative and high risk) for bronchoscopy. Required pre-bronchoscopic studies for routine and special cases are defined, as are indications for premedication, intubation and general anesthesia. Requirements for the setting, support personal and instruments are specified. Guidelines for topical anesthesia and techniques for insertion of the endoscope are suggested. The technique, indications and limitations of bronchoalveolar lavage, bronchial brushing and biopsy and transbronchial needle biopsy are defined. The utility and limitations of the various therapeutic techniques of bronchoscopy (laser, radiotherapy and stents) are defined. Norms to safeguard the patient, instruments and operator are emphasized. PMID:9611657

  20. Quantitative analysis of the effects of the exotic Argentine ant on seed-dispersal mutualisms

    PubMed Central

    Rodriguez-Cabal, Mariano A.; Stuble, Katharine L.; Nuñez, Martin A.; Sanders, Nathan J.

    2009-01-01

    Although it is increasingly clear that exotic invasive species affect seed-dispersal mutualisms, a synthetic examination of the effect of exotic invasive species on seed-dispersal mutualisms is lacking. Here, we review the impacts of the invasive Argentine ant (Linepithema humile) on seed dispersal. We found that sites with L. humile had 92 per cent fewer native ant seed dispersers than did sites where L. humile was absent. In addition, L. humile did not replace native seed dispersers, as rates of seed removal and seedling establishment were all lower in the presence of L. humile than in its absence. We conclude that potential shifts in plant diversity and concomitant changes in ecosystem function may be a consequence of Argentine ant invasions, as well as invasions by other ant species. Because very few studies have examined the effects of non-ant invasive species on seed-dispersal mutualisms, the prevalence of disruption of seed-dispersal mutualisms by invasive species is unclear. PMID:19465575

  1. Acceptance and intake of gel and liquid sucrose compositions by the Argentine ant (Hymenoptera: Formicidae).

    PubMed

    Silverman, J; Roulston, T H

    2001-04-01

    Liquids and gels are common delivery forms used in commercial ant baits, but the relative effectiveness of each is unknown. We compared the feeding responses of the Argentine ant, Linepithema humile (Mayr), to liquid and gel compositions of sucrose. In choice assays, more workers were counted on gel than liquid; however, substantially more liquid was consumed. Because workers could stand on the gel, more workers could feed simultaneously on the gel. The feeding bouts of individual workers, however, were much less efficient at extracting sucrose in gel form. Workers fed eightfold longer on the gel, yet removed fivefold less sucrose than workers feeding on liquid. This potential bias should be considered during attraction and palatability studies that use physically different bait compositions. When the toxicant fipronil was added to the compositions, a greater proportion of the colony died after workers had fed on liquid than gel baits. This finding suggests that liquid formulations may provide more effective control of Argentine ants due to the greater speed and abundance in which it is ingested. PMID:11332847

  2. A collaborative characterization of North American grasslands and rangelands: climate, ecohydrology and carbon sink-source dynamics

    NASA Astrophysics Data System (ADS)

    Petrie, M. D.; Brunsell, N. A.; Vargas, R.; Collins, S. L.

    2013-12-01

    Grassland and rangeland ecoregions extend across the North American continent and exhibit diversity in climate, ecosystem services, and biophysical processes. In many grasslands and rangelands, the potential for reductions in ecosystem services and for large-scale ecosystem state change may increase under future climate scenarios. Climate change projections for North America vary, however, and the way changing climate will influence specific ecoregions is largely unknown. To better understand the regional effects of climate change on grasslands and rangelands, it is important to better understand the biophysical characteristics of these systems locally, and to identify the sensitivity of these characteristics to observed climate variation. In our study, we propose to use eddy covariance, soil moisture and precipitation data to identify how the grasslands and rangelands of North America differ in their responses to climate variability through time, with specific focus on the active growing season. Our primary goal is to determine the sensitivity of ecosystem Net Primary Productivity [NPP] to variation in temperature and precipitation patterns, and classify North American grasslands and rangelands by these sensitivities in addition to more standard climate and productivity variables. Our preliminary analyses in mesic, semiarid and arid grasslands in Kansas, Colorado and New Mexico show significant (P < 0.05) differences in climate, carbon sink strength and growing season length, and suggest that patterns of seasonal productivity and precipitation sensitivity may elucidate important grassland and rangeland responses to changing climate. Using change in Gross Primary Productivity (GPP) as an indicator of the onset of photosynthesis in spring and of senescense in the fall, grassland and rangeland ecosystems in Kansas (top and bottom left panels) and New Mexico (bottom right panel) display differing patterns of activity throughout the year.

  3. Differential use of the Argentine shelf by wintering adults and juveniles southern giant petrels, Macronectes giganteus, from Patagonia

    NASA Astrophysics Data System (ADS)

    Blanco, Gabriela S.; Quintana, Flavio

    2014-08-01

    To study habitat use and at-sea movements of southern giant petrels (SGP) during non-breeding period, we deployed 15 satellite transmitters (six adults, nine juveniles) at Isla Arce and Isla Gran Robredo colonies in Patagonia, Argentina. Birds were instrumented during 81.4 ± 37 days. Adult birds used 74% of the Argentine shelf concentrating mainly at the shelf break, middle shelf waters, and the surroundings of the colony. After fledging, juveniles spread to the Argentine, Uruguayan and Brazilian shelves within the South Atlantic. Adults alternated at-sea excursions (12 ± 5 days) with periods at the colony of 3 ± 0.3 days. Contrarily, juveniles moved first to the shelf break and then traveled northwards reaching the south of Brazil. There was some spatial overlap between age classes, but only during the first 30 days after juveniles had fledged; thereafter there was not overlap between the areas used by both age classes. The Argentine shelf is widely used by different species offering a suitable environment for foraging; this may be why adults SGP from Patagonian colonies spend all year-round within the Argentine shelf. The identification of used areas of non-breeding SGP fills a gap in the species knowledge contributing not only to the preservation the species, but also to the management of marine areas globally recognized as important for many other Procellariiformes.

  4. Characterizing rangeland using multispectral remotely sensed data and multi-scale ecological units

    NASA Astrophysics Data System (ADS)

    Maynard, Catherine Cae Lee

    In this study ecological range unit (ERU) delineations combined with multispectral satellite data were examined to address the need for consistent, spatially accurate, and temporally current methods to inventory rangeland and estimate relative biomass productivity in the context of ecologically sensitive site parameters. ERUs, Landsat 7 ETM+ combined band values, and vegetation index data from 13 scenes acquired from June 2000 to August 2002 were used as predictive variables in linear regression estimates of total biomass using field data collected from 263 locations within 24 ecological range sites on 5 Montana ranches. GIS spatial data analysis techniques were applied to certified soils data themes and published landscape level ecological units to produce the ERU categories used to stratify the field data collection and image analysis, and as a method to test the use of an independent data set for addressing the known influence of soil and site variability on the spectral response of vegetation. ERU categories, in combination with the near and mid-infrared bands (Band 4, 0.75--0.90 mum; Band 7 2.09--2.35 mum), were significant independent variables, and in linear regression predictions collectively explained 66% of the variability in total biomass (p -value < 0.001), as compared to 52% explained by the combined bands alone, suggesting that ERU categories might be accounting for a component of soil variability. This report also introduces an efficient, remote sensing directed method for preliminary identification of locations within ERUs where indicators of soil and site stability or biotic integrity might be outside the established means. A comparison between sites with spectrally anomalous brightness, greenness, and wetness Tasseled Cap indices and selected measurements of spectrally sensitive rangeland ecological health indicators were used to develop a classification method for locating and screening rangeland categories. Pixels where site productivity and

  5. Application of high resolution images from unmanned aerial vehicles for hydrology and rangeland science

    NASA Astrophysics Data System (ADS)

    Rango, A.; Vivoni, E. R.; Anderson, C. A.; Perini, N. A.; Saripalli, S.; Laliberte, A.

    2012-12-01

    A common problem in many natural resource disciplines is the lack of high-enough spatial resolution images that can be used for monitoring and modeling purposes. Advances have been made in the utilization of Unmanned Aerial Vehicles (UAVs) in hydrology and rangeland science. By utilizing low flight altitudes and velocities, UAVs are able to produce high resolution (5 cm) images as well as stereo coverage (with 75% forward overlap and 40% sidelap) to extract digital elevation models (DEM). Another advantage of flying at low altitude is that the potential problems of atmospheric haze obscuration are eliminated. Both small fixed-wing and rotary-wing aircraft have been used in our experiments over two rangeland areas in the Jornada Experimental Range in southern New Mexico and the Santa Rita Experimental Range in southern Arizona. The fixed-wing UAV has a digital camera in the wing and six-band multispectral camera in the nose, while the rotary-wing UAV carries a digital camera as payload. Because we have been acquiring imagery for several years, there are now > 31,000 photos at one of the study sites, and 177 mosaics over rangeland areas have been constructed. Using the DEM obtained from the imagery we have determined the actual catchment areas of three watersheds and compared these to previous estimates. At one site, the UAV-derived watershed area is 4.67 ha which is 22% smaller compared to a manual survey using a GPS unit obtained several years ago. This difference can be significant in constructing a watershed model of the site. From a vegetation species classification, we also determined that two of the shrub types in this small watershed(mesquite and creosote with 6.47 % and 5.82% cover, respectively) grow in similar locations(flat upland areas with deep soils), whereas the most predominant shrub(mariola with 11.9% cover) inhabits hillslopes near stream channels(with steep shallow soils). The positioning of these individual shrubs throughout the catchment using

  6. Satellite monitoring the rangeland degradation under the impacts of climatic and socio-economic changes over central Asia

    NASA Astrophysics Data System (ADS)

    Wang, K.; Zhang, L.; Dai, L.; Yan, D.

    2012-12-01

    Central Asia, encompassing the republics of Kazakhstan, Kyrgyz, Uzbekistan, Turkmenistan, Tajikistan and China's western Sinkiang, is a typical arid and semi-arid area. The climate in Central Asia is extreme arid, where summer is hot, cloudless and dry, and winter is moist and relatively warm in the south and cold and dry in the north. Rangeland, accounting for 46% of the entire area, is the main vegetation type in this area. Recent findings showed that climate change had caused unprecedented rangeland degradation in Central Asia over the past 30 years. Socio-economical change and environmental change due to the collapse of Soviet Union also accelerated rangeland degradation. Rangeland degradation adversely further deteriorated the environment. With the development of high resolution remote sensing images, an increasing attention has paid to study rangeland degradation in this area. However, previous investigations based on either Advanced Very High Resolution Radiometer (AVHRR) or Moderate Resolution Imaging Spectroradiometer (MODIS) data, has not integrate multi-resolution satellite data for investigating vegetation change and its response to climatic and socio-economic change . In this paper, we employed 30 years' remote sensing data, including both AVHRR ( 1982-2006) and MODIS (2000-2011) satellite data, and in-situ meteorological and social data (e.g. population, economic, and land use change data), to investigate rangeland degradation in the central Asia. We 1) analyzed the spatial-temporal variations of vegetation changes during the past 30 years, and 2) evaluated the roles of climatic and socio-economic factors as potential causes of observed vegetation changes. The results showed extensive area had statistically significant degradation trends (p<0.05). Precipitation was the main driver of rangeland degradation, while there were relatively weaker relationships between temperature and NDVI, indicating that water deficit largely limited vegetation activity

  7. Solid recovered fuels in the steel industry.

    PubMed

    Kepplinger, Werner L; Tappeiner, Tamara

    2012-04-01

    By using waste materials as alternative fuels in metallurgical plants it is possible to minimize the traditionally used reducing agents, such as coke, coal, oil or natural gas. Moreover, by using waste materials in the metallurgical industry it is feasible to recover these materials as far as possible. This also represents another step towards environmental protection because carbon dioxide emissions can be reduced, if the H(2) content of the waste material is greater in comparison with that of the substituted fuel and the effects of global warming can therefore be reduced. In the present article various solid recovered fuels and their applications in the metallurgical industry are detailed. PMID:22086964

  8. Proportion of recovered waterfowl bands reported

    USGS Publications Warehouse

    Geis, A.D.; Atwood, E.L.

    1961-01-01

    Data from the annual mail survey of waterfowl hunters in the United States were used to estimate the total numbers of banded waterfowl that were shot. These estimates were compared with Banding Office records to estimate the proportion of recovered bands that was reported. On the average, about two banded birds were recovered for each one reported. The proportion reported was higher for some areas and for some species than for others. The proportion reported was higher when more of the reports came through employees of conservation agencies.

  9. Use of Rainfall Simulation and Concentrated Flow Experiments to Characterize Rangeland Hydrologic and Erosional Processes in the Great Basin, USA

    NASA Astrophysics Data System (ADS)

    Pierson, Fred; Robichaud, Pete; Williams, Jason; Kormos, Patrick; Al-Hamdan, Osama; Boll, Jan

    2010-05-01

    Much of what is known about rangeland hydrology comes from short-term, poorly replicated studies of small (0.25 - 1 m2) field plots and personal observations of hydrologic behavior on gently sloping semi-arid shrub and grassland sites. Historical rangeland models have been largely based on these limited datasets and inferences from crop land studies. In recent years, we have sought to expand the inference space through the use of rainfall simulations and concentrated flow experiments from the small to large (13.5 - 32.5 m2) plot scales on steeply sloping, disturbed and undisturbed rangeland ecosystems. We present an overview of one such multi-year rainfall simulation study and highlight how the methodology and results specifically address current voids in the understanding of hydrology and erosion processes from steeply sloping, semi-arid rangeland landscapes. We further demonstrate how the methodologies and aggregated results from studies across a range of plant communities and degrees of disturbance reveal consistent trends in runoff and erosional behavior. The aggregated results advance the understanding of rangeland hydrology and erosion processes and present a well replicated dataset from which hydrologic model parameters can be derived.

  10. Evaluation of Utah trefoil (Lotus utahensis Ottley) collections for rangeland restoration/revegetation in the southern Great Basin and Colorado Plateau

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Wildfires, weed invasion, and various land uses have created a need for revegetation/restoration of rangeland ecosystems in the Intermountain Region of the western U.S.A. These rangelands may require revegetation/restoration to improve degraded conditions, speed recovery after wildfires, minimize s...

  11. Relationship Between Forage Allowance and Grazing Efficiency in the Great Plains: Implications for Managing Rangelands for Both Livestock Production and Desired Ecosystem Goods and Services

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Emergence of desired ecosystem goods and services from rangelands as a societal benefit and a potential income source for land managers has implications regarding the management of plant communities traditionally used primarily for livestock production. Contemporary decision-making on rangelands in ...

  12. 27 CFR 19.458 - Restoration and redenaturation of recovered denatured spirits and recovered articles.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Restoration and redenaturation of recovered denatured spirits and recovered articles. 19.458 Section 19.458 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY...

  13. Inventory of forest and rangeland and detection of forest stress

    NASA Technical Reports Server (NTRS)

    Heller, R. C. (Principal Investigator); Aldrich, R. C.; Weber, F. P.; Driscoll, R. S.

    1972-01-01

    The author has identified the following significant results. Seventy-two ground sensors were interfaced with three DCP'S at the Black Hills test site. Unfortunately, the transmitters had to be returned for modification and forestry sensed data is not available. The DCP's did operate properly from the Berkeley laboratory and data were recovered from the Goldstone and Alaska stations via Goddard. Replicated training sets and test sets have been selected from all three test site areas in preparation for the receipt of ERTS imagery and digital tapes. From 600 and 800 points have been selected at each site location and UTM coordinates determined. Templates are being made of these sets. As of September 1, ERTS-generated data had not been received and no statements can be made regarding quality or suitability for forest and range experiments. Aerial photography (scale 1:32,000) of the Manitou (226 C) and Black Hills (226 A) sites was taken with CIR in June. Various scales (1:2,000; 1:10,000; 1:20,000; and 1:40,000) of 70 mm photographs were obtained at Manitou with normal color, CIR, and panchromatic in August.

  14. Recovered Harvard Variables In The Milky Way

    NASA Astrophysics Data System (ADS)

    Weirich, J. R.; Samus, N.; Baranov, A.

    2001-12-01

    Hundreds of Harvard variables lacking finding charts still need to be recovered. Besides the Harvard plate stacks, much can be done using plate collections of other observatories. For several years, we have successfully used the plate collection of the Maria Mitchell Observatory to recover "lost" variables. Plates of the Moscow collection have also been used for this purpose for many years. In 2001, we successfully recovered on Nantucket and Moscow plates ten lost Harvard variables in the constellations Sagittarius, Scorpius, and Scutum. We studied some of these stars in more detail. Six of them are shown to be pulsating red giants (semiregulars or Miras). Among the four others, two cases are especially interesting. AM Sco, earlier considered a possible Mira-type object, is probably a young irregular variable (Orion variable), and AQ Sco, earlier classified as a slow pulsating variable or an Orion variable, is an RR Lyrae star. For the recovered stars, we will present accurate coordinates, finding charts, and the results of our new photographic study. This project was supported by the NSF/REU grant AST-9820555 and the Nantucket Maria Mitchell Association.

  15. Applications for Energy Recovering Free Electron Lasers

    SciTech Connect

    George Neil

    2007-08-01

    The availability of high-power, high-brilliance sources of tunable photons from energy-recovered Free Electron Lasers is opening up whole new fields of application of accelerators in industry. This talk will review some of the ideas that are already being put into production, and some of the newer ideas that are still under development.

  16. The Recovering Female Alcoholic: A Family Affair.

    ERIC Educational Resources Information Center

    Rolls, Judith A.

    To ensure a positive prognosis, the recovering female alcoholic requires family therapy as an adjunct to her regular treatment program. Research indicates that the characteristics affecting a person's ability to secure and use treatment include (1) predisposing factors; (2) attitudes toward alcohol and health care; (3) personal enabling factors;…

  17. Process for recovering filler from polymer

    DOEpatents

    Smith, Maurice L.; Smith, Robert M.

    1978-01-01

    This disclosure relates to a process for recovering filler material from a polymeric matrix by reacting the matrix at an elevated temperature in a gas atmosphere with a controlled oxidizing potential and thereafter separating and cleaning the residue from the reaction mixture.

  18. Stress Levels of Recovering Drug Addicts.

    ERIC Educational Resources Information Center

    LaMon, Brent C.; Alonzo, Anthony

    It appears that chronic drug use may develop as a means of coping in which individuals use self-medication to produce a more desirable state of being. Because drugs are often used to cope with stress, this study examined stress among recovering male drug addicts (N=23) from an urban substance abuse program by administering a self-report inventory…

  19. Effects of grazing on photosynthetic features and soil respiration of rangelands in the Tianshan Mountains of Northwest China

    PubMed Central

    Liu, Hua; Zang, Runguo; Chen, Han Y. H.

    2016-01-01

    Rangelands play a critical role in the global carbon cycle. However, the eco-physiological mechanisms associated with the effects of grazing on leaf photosynthesis and soil respiration remain poorly understood. To examine the impacts of grazing on leaf photosynthesis and soil respiration, we measured the photosynthetic parameters of the dominant species (Trifolium repens) and the soil respiration in grazed and ungrazed rangelands in the Tianshan Mountains of China. We found that grazing reduced the daily maximum net photosynthetic rate and soil respiration rates by 35% and 15%, respectively. The photosynthetic quantum yield, dark respiratory rate, and water use efficiency of T. repens leaves were reduced in grazed plots by 33.3%, 69.2%, and 21.5%, respectively. Our results demonstrated that grazing reduced carbon assimilation while increasing soil respiration within the rangelands in the Tianshan Mountains. PMID:27452980

  20. Effects of grazing on photosynthetic features and soil respiration of rangelands in the Tianshan Mountains of Northwest China.

    PubMed

    Liu, Hua; Zang, Runguo; Chen, Han Y H

    2016-01-01

    Rangelands play a critical role in the global carbon cycle. However, the eco-physiological mechanisms associated with the effects of grazing on leaf photosynthesis and soil respiration remain poorly understood. To examine the impacts of grazing on leaf photosynthesis and soil respiration, we measured the photosynthetic parameters of the dominant species (Trifolium repens) and the soil respiration in grazed and ungrazed rangelands in the Tianshan Mountains of China. We found that grazing reduced the daily maximum net photosynthetic rate and soil respiration rates by 35% and 15%, respectively. The photosynthetic quantum yield, dark respiratory rate, and water use efficiency of T. repens leaves were reduced in grazed plots by 33.3%, 69.2%, and 21.5%, respectively. Our results demonstrated that grazing reduced carbon assimilation while increasing soil respiration within the rangelands in the Tianshan Mountains. PMID:27452980