474 research outputs found

    A Guide to the Common Native and Exotic Thistles of South Dakota

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    This guide was compiled to provide an aid for the rapid identification of the more common pest and non-pest thistle species in South Dakota. Because of the great expense of managing and controlling invasive thistles in rangelands, pastures, and croplands, it is essential to be accurate in the identification of any species at hand. The recognition of native species not only helps maintain local biodiversity, but also prevents wasted effort, controls costs, and minimizes herbicide use and chemical pollution. It should be noted that native thistles are important both as floral resources for native pollinating insects and as seed sources for birds. To a certain degree, invasive thistle species are also important in these regards, but their negative impact to native communities outweighs their supplementary value. There are 11 species of plants in South Dakota commonly called thistle. This does not include sow thistle (Sonchus spp.) or Russian thistle (Salsola spp.), neither of which is closely related to true thistles. Six of these 11 are native species and are natural components of prairie, meadow, or woodland habitats. The remaining five are exotic species from Europe and Asia that were introduced to the U.S. The exotics are invasive weeds and have significant economic impact on crop and livestock production, native biological community stability, and recreation. This guide is useful for discriminating between the five native and five exotic species most commonly found in South Dakota

    AN UPDATE ON THE REVISION OF THE HANDBOOK, PREVENTION AND CONTROL OF WILDLIFE DAMAGE

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    Wildlife species have an important role in our environment and they provide many recreational, economic, and aesthetic benefits. Management of these species is necessary, however, when they cause damage to agricultural, industrial, and natural resources, and threaten personal property, public health, and safety. Published estimates indicate that commensal rodents, field rodents, and predators combined, cause \u3e$2 billion in damage in North America annually. Because of the social and economic impacts of wildlife damage, there is a need for up-to-date information on the prevention and control of wildlife damage for producers, resource managers, administrators, and the public. The book, Prevention and Control of Wildlife Damage, edited by Robert M. Timm (1983) (Handbook) has served as the principal reference in this field. The Handbook currently contains 65 chapters (650 pages) by 45 authors who are recognized as authorities in wildlife damage management. Over 8,500 copies have been sold and are being used by personnel from the U.S. Department of Agriculture -Extension Service (ES) and Division of Animal Damage Control (ADC), natural resources agencies, municipalities, private pest control operations and others throughout the United States, as well as other countries. The Handbook has been reprinted four times and was recognized by the Natural Resources Council of America as Outstanding Book for 1983. Previous Handbook sponsors include the University of Nebraska-Cooperative Extension (UNCE), ES, U.S. Environmental Protection Agency (EPA) and the Great Plains Agricultural Council

    Vegetation Trends on a Waste Rock Repository Cap in the Northern Black Hills

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    We assessed successional trends, long-term vegetation sustainability, and soil surface protection during the 2005-2007 growing seasons on the 32-ha Ruby Gulch Waste Rock Repository cap. The cap consisted of 150 cm of rock and soil covering a polyethylene membrane which in turn covered mining waste rock in order to prevent leaching of heavy metals and acidic water into streams. Following construction in 2003, a contractor applied a grass-forb seed mixture to provide soil-surface protection especially for steeply sloped portions of the cap. In 2005, we established 56, 1-m2 plots, and 20, 20-m transects to annually measure canopy cover, basal cover, and species diversity over three growing seasons. Our results showed a decrease in species richness, including a decline in broad-leaved plants (especially clovers [Trifolium spp.]), near disappearance ofthickspike wheatgrass (Elymus lanceolatus), and poor establishment of western wheatgrass (E. smithii). Kentucky bluegrass (Poa pratensis), fescue (including Festuca brevipila and F. ovina), intermediate wheatgrass (E. hispidus) and slender wheatgrass (E. trachycaulus) increased or remained stable. With declining diversity, species composition among plots and transects became more similar over the three-year period. A severe drought and grasshopper outbreak in 2006 likely accelerated the compositional shift. Increases in vegetative cover and litter appear adequate to prevent excessive erosion, and despite low diversity, the vegetation appears self-sustaining

    Patterns of Occurrence from Spring Bird Counts at Oak Lake Field Station, Brookings County, South Dakota

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    Over 400 bird species have been recorded from South Dakota. Many of these birds simply pass through to other habitats. Others take residence seasonally while a few species are permanent residents. Recent studies suggest that spring migrants may be arriving earlier than previously recorded and these shifting migration times may be reflected in annual spring bird counts. The objective of this effort was to summarize patterns in bird occurrence from spring bird counts held at the Oak Lake Field Station, Brookings County, South Dakota (mid-May from 1995 to 2008). Tallies of bird species seen along a regular route were made over a period of 3-4 hours by groups of 4-15 individuals. Since 1994, 16 orders, 41 families, 110 genera and 168 species of birds have been recorded from formal observations at the station. During the period 1996-2000, 64 bird species were recorded during the spring bird counts (average = 29/yr). Accounts from the same route during the period 2004-2008 yielded 86 total species (average = 48/yr). The Jaccard Coefficient of similarity in occurrence between these two survey periods was 48.5%. Woodpeckers, swallows, wrens, gulls and terns were noted more frequently from later surveys. Consistently implemented spring tallies together with data on dates of first arrival and warmth sum accumulations may be useful in detecting early biotic effects from global climate change

    EFFECTS OF HERBICIDES AND GRAZING ON FLORISTIC QUALITY OF NATIVE TALLGRASS PASTURES IN EASTERN SOUTH DAKOTA AND SOUTHWESTERN MINNESOTA

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    Historic herbicide use and grazing have influenced natural diversity and quality of native pasturelands in the Great Plains. Floristic quality assessments are useful to assist agencies in prioritizing conservation practices to enhance native grasslands. The objective of this study was to determine the effects of past land-use practices on the floristic quality of remnant native pastures in eastern South Dakota and southwestern Minnesota. Floristic quality assessments were conducted on 30 native pastures and categorized by past management practices (herbicide application and grazing intensity). Mean coefficient of conservatism (C) and floristic quality index (FQI) were calculated for each site~Results showed that increased herbicide use and grazing intensity resulted in a lower species richness, forb C ,and FQI. However, grass and grasslike plants were minimally affected. Pastures that were infrequently sprayed with herbicides and lightly grazed consistently had the highest species richness, C ,and FQI. Pastures with no grazing produced similar values to those with moderate grazing. Pastures managed as preserves or wildlife habitat areas had higher FQI than those managed for livestock grazing. The implications of this study should further help ecologists and managers understand the positive and negative effects of grazing practices and herbicide application on tallgrass prairie remnants

    EFFECTS OF HERBICIDES AND GRAZING ON FLORISTIC QUALITY OF NATIVE TALLGRASS PASTURES IN EASTERN SOUTH DAKOTA AND SOUTHWESTERN MINNESOTA

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    Historic herbicide use and grazing have influenced natural diversity and quality of native pasturelands in the Great Plains. Floristic quality assessments are useful to assist agencies in prioritizing conservation practices to enhance native grasslands. The objective of this study was to determine the effects of past land-use practices on the floristic quality of remnant native pastures in eastern South Dakota and southwestern Minnesota. Floristic quality assessments were conducted on 30 native pastures and categorized by past management practices (herbicide application and grazing intensity). Mean coefficient of conservatism (C) and floristic quality index (FQI) were calculated for each site~Results showed that increased herbicide use and grazing intensity resulted in a lower species richness, forb C ,and FQI. However, grass and grasslike plants were minimally affected. Pastures that were infrequently sprayed with herbicides and lightly grazed consistently had the highest species richness, C ,and FQI. Pastures with no grazing produced similar values to those with moderate grazing. Pastures managed as preserves or wildlife habitat areas had higher FQI than those managed for livestock grazing. The implications of this study should further help ecologists and managers understand the positive and negative effects of grazing practices and herbicide application on tallgrass prairie remnants

    Influence of Role Models and Hospital Design on the Hand Hygiene of Health-Care Workers

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    We assessed the effect of medical staff role models and the number of health-care worker sinks on hand-hygiene compliance before and after construction of a new hospital designed for increased access to handwashing sinks. We observed health-care worker hand hygiene in four nursing units that provided similar patient care in both the old and new hospitals: medical and surgical intensive care, hematology/oncology, and solid organ transplant units. Of 721 hand-hygiene opportunities, 304 (42%) were observed in the old hospital and 417 (58%) in the new hospital. Hand-hygiene compliance was significantly better in the old hospital (161/304; 53%) compared to the new hospital (97/417; 23.3%) (p<0.001). Health-care workers in a room with a senior (e.g., higher ranking) medical staff person or peer who did not wash hands were significantly less likely to wash their own hands (odds ratio 0.2; confidence interval 0.1 to 0.5); p<0.001). Our results suggest that health-care worker hand-hygiene compliance is influenced significantly by the behavior of other health-care workers. An increased number of hand-washing sinks, as a sole measure, did not increase hand-hygiene compliance

    Turbulence Transport Modeling and First Orbit Parker Solar Probe (PSP) Observations

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    Parker Solar Probe (PSP) achieved its first orbit perihelion on November 6, 2018, reaching a heliocentric distance of about 0.165 au (35.55 R⊙_\odot). Here, we study the evolution of fully developed turbulence associated with the slow solar wind along the PSP trajectory between 35.55 R⊙_\odot and 131.64 R⊙_\odot in the outbound direction, comparing observations to a theoretical turbulence transport model. Several turbulent quantities, such as the fluctuating kinetic energy and the corresponding correlation length, the variance of density fluctuations, and the solar wind proton temperature are determined from the PSP SWEAP plasma data along its trajectory between 35.55 R⊙_\odot and 131.64 R⊙_\odot. The evolution of the PSP derived turbulent quantities are compared to the numerical solutions of the nearly incompressible magnetohydrodynamic (NI MHD) turbulence transport model recently developed by Zank et al. (2017). We find reasonable agreement between the theoretical and observed results. On the basis of these comparisons, we derive other theoretical turbulent quantities, such as the energy in forward and backward propagating modes, the total turbulent energy, the normalized residual energy and cross-helicity, the fluctuating magnetic energy, and the correlation lengths corresponding to forward and backward propagating modes, the residual energy, and the fluctuating magnetic energy
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