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Patterns Of Soil Nitrogen Dynamics In A Central Appalachian Hardwood Forest Ecosystem, Bradley Michael Yurish

Theses, Dissertations and Capstones

Increasing awareness of the potential effects of acidic deposition prompted a watershed manipulation project at the Fernow Experimental Forest (FEF), West Virginia, in 1987. In this project, an acidifying agent, (Nf4)2S04 , was applied to an entire watershed to better understand ecosystem responses to simulated acid deposition in excess of ambient levels. In ecosystems receiving elevated N levels, increased soil N may contribute to soil acidification, lead to nutrient imbalances in plants, increase rates of nitrification, increase leaching of No3• and pollute surface waters. This study was designed to assess changes of three watersheds that received varied N inputs. The …

Population Structuring And Patterns Of Morphological Variation In Californian Styrax (Styracaceae), Peter Fritsch

Aliso: A Journal of Systematic and Floristic Botany

Recent studies of genetic variation within and among populations and phylogenetic estimates have provided evidence bearing on the evolutionary history and taxonomy of Styrax in California (S. redivivus). In this paper, data from these studies are further analyzed and integrated with new data from morphology to gain insight into the nature and taxonomic significance of character variation within this species. Six morphological characters thought to be important in the delimitation of infraspecific taxa within S. redivivus were measured on 52 herbarium specimens and analyzed with Pearson correlations and multivariate methods. Five characters are significantly associated with latitude and …

Using Confocal Microscopy In The Study Of Plant Structure And Development, Mark P. Running, Elliot M. Meyerowitz

Aliso: A Journal of Systematic and Floristic Botany

The widespread application of confocal laser scanning microscopy has revolutionized biological imaging. We have developed a protocol for using confocal microscopy to examine the development of wild type and mutant Arabidopsis thaliana, overcoming the technical difficulties associated with examining whole-mounted plant tissue. This allowed us to rapidly determine the underlying cellular defects that lead to the morphological changes visible in several mutants, and has led to a greater understanding of the mechanisms involved in the control of floral organ number.

Diversity And Evolution Of Seedling Baupläne In Perlargonium (Geraniaceae), Cynthia S. Jones, Robert A. Price

Aliso: A Journal of Systematic and Floristic Botany

The genus Pelargonium (Geraniaceae) exhibits tremendous variation in growth form. We apply a broadly defined concept of Bauplan in our study of growth form, architectural and anatomical features of early seedling development in the type subgenus. We analyze variation in these features within a phylogenetic framework based on sequence comparisons of internal transcribed spacer regions (ITS) of nuclear ribosomal DNA.

Preliminary ITS sequence comparisons show strong support for two major clades. One major clade contains two subgroups, one consisting of three previously recognized sections of more or less woody shrubs and subshrubs (sections Pelargonium, Glaucophyllum and Campylia), and …

PhosphoEnolPyruvate Carboxylase: A Ubiquitous, Highly Regulated Enzyme In Plants, Raymond Chollet, Jean Vidal, Marion H. O'Leary

Center for Plant Science Innovation: Faculty Publications

Since plant phosphoenolpyruvate carboxylase (PEPC) was last reviewed in the Annual Review of Plant Physiology over a decade ago (O’Leary 1982), significant advances have been made in our knowledge of this oligomeric, cytosolic enzyme. This review highlights this exciting progress in plant PEPC research by focusing on the three major areas of recent investigation: the enzymology of the protein; its posttranslational regulation by reversible protein phosphorylation and opposing metabolite effectors; and the structure, expression, and molecular evolution of the nuclear PEPC genes. It is hoped that the next ten years will be equally enlightening, especially with respect to the three-dimensional …

Inventory For Endangered, Threatened, And Rare Plant And Animal Species Within The Floodplain Corridor Of The Middle Loup River Basin, Nebraska Natural Heritage Program

Nebraska Game and Parks Commission: White Papers, Conference Presentations, and Manuscripts

In April 1996 the Nebraska Game and Parks Commission (NGPC) entered into agreement with the U. S. Department of the Interior Bureau of Reclamation (BOR) to conduct inventory work for endangered, threatened, and rare plant and animal species within the floodplain corridor of the Middle Loup River basin in Nebraska. This district includes the Farwell and Sargent Irrigation Districts. The impetus for such inventory work is the renewal of current water services contracts between BOR and irrigation districts that will expire in 1988. BOR has stated the need to balance the interests of the irrigation districts and their clients, with …

Center For Grassland Studies Newsletter, Winter 1996, Volume 2, No. 1

Center for Grassland Studies: Newsletters

Contents:

Turfgrasses Benefit People and Their Environment by Robert (Bob) C. Shearman, Department of Horticulture, UNL and Exec. Director of the National Turfgrass Evaluation Program

Conservation Reserve Program Entering an Unknown Phase by Richard T. Clark, Department of Agricultural Economics, UNL

Golf Growing in Popularity

Advisory Council Identifies Needs

Funding Opportunities

Bulletin No 4315 - Western Australian Agricultural & Fishery Exports At A Glance...1995/96, Graeme Robertson Dr, P. P. Rogers

Bulletins 4000 -

Second edition (revised and updated) January 1997.

Western Australia's economic growth and high productivity is based on a well established export-oriented economy that relies heavily on primary production.

Our abundant and diverse range of agricultural and fish products is supported by highly innovative and dynamic primary industries. These are backed by modern financial and physical infrastructure.

Western Australia's agricultural industries and fisheries have an international reputation for a professional approach to business and a proven track record in producing and supplying food and fibre products of consistently high quality. Clean air, unpolluted oceans and waterways, and abundant quality farmland are …

Western Flower Thrips, David F. Cook, Ian Dadour, Ernie Steiner, Brett Scourse

Journal of the Department of Agriculture, Western Australia, Series 4

Western flower thrips (Franklinislla occidentalis Pergands) is a serious pest of floral and vegetable crops. From its original habitat in western USA it has now spread throughout North America, Mexico, New Zealand and Europe. David Cook, Ian Dadour, Ernis Steiner and Brett Scourse outline its biology and the control options available.

Weeds : A Curse For Native Plants In Farm Woodlands, Max Abensperg-Traun

Journal of the Department of Agriculture, Western Australia, Series 4

Weeds have a mJOR IMPct on native Australian plants, particularly in the tropical north and the agricultural regions of southern Australia.

Maz Abensperg-Traun, and his clooeagues from the CSIRO Division of Wildlife and Ecology, explainthe effects of weed invasion on the diversity of native herbaceous plants in faarm woodlands in the centeral wheatbelt of south-west Western Australia.

Weeds Can Poison Crops, Aik Hock Cheam

Journal of the Department of Agriculture, Western Australia, Series 4

Weeds can interfere with the growth of a crop simply by competing with the crop for nutrients, moisture and light. But some weeds also release chemicals that inhibit the germination and growth of crop plants; the technical term for this is allelopathy. Aik Cheam outlines the problems caused by two common weeds and the discusses preventative measures.

Does The Monocot Mode Of Leaf Development Characterize All Monocots?, Geeta Bharathan

Aliso: A Journal of Systematic and Floristic Botany

Patterns of early leaf development in monocots are analyzed in a phylogenetic context. Recent developmental and phylogenetic studies enable this reevaluation of the leaf base model of the developing monocot leaf. Two questions are addressed: a) is the presence of the Vorläuferspitze (fore-runner tip) invariably correlated with development of the lamina from the lower leaf zone? and b) was the ancestral monocot characterized by the leaf base mode of development? Scanning electron microscopic observations are made of young primorida using the mold and cast method. These data are combined with data from the literature and examined in a phylogenetic context …

Applications Of An Ecophysiological Model For Irrigated Rice (Oryza Sativa)- Echinochloa Competition, John L. Lindquist, Martin Kropff

Department of Agronomy and Horticulture: Faculty Publications

A. simulation model of rice-barnyardgrass competition for light was used for two management applications. First simulations using47 weather data sets from four locations in Asia were conducted to evaluate the influence of weather variation on single year economic threshold densities of barnyardgrass. Second rapid leaf area expansion and leaf area index were evaluated as potential indicators of improved rice competitiveness and tolerance to barnyardgrass. Influence of weather variation on single year economic thresholds was small under the assumption that competition was for light only. Increasing early leaf area expansion rate reduced simulated barnyardgrass seed production and increased single year economic …

Germplasm And Cultivar Development, M. D. Casler, Jeffrey F. Pedersen, G. C. Eizenga, S. D. Stratton

Department of Agronomy and Horticulture: Faculty Publications

Cool-season forage grasses have evolved, and continue to evolve, in natural ecosystems subject to environmental factors both in the presence and absence of human influences. The literature often lacks facts describing the evolution and domestication of forage grasses. Furthermore, the literature on this subject mainly deals with evolution of species in the broad scope, i.e., on a scale of hundreds of thousands or millions or years. Thus, some of our conclusions are necessarily speculative and are highly subject to the nature of the research that has been reported. We describe the forces of selection that act upon cool-season forage grasses …

Potential For Controlling The Spread Of Centaurea Maculosa With Grass Competition, John L. Lindquist, Bruce D. Maxwell, T. Weaver

Department of Agronomy and Horticulture: Faculty Publications

ABSTRACT.-Spotted knapweed (Centaurea maculosa Lam.) is a major rangeland and roadside weed of the northern Rocky Mountains. It is often found in plant communities dominated by Pseudoroegneria spicatum or Festuca idahoensis, but it rarely invades roadsides dominated by Bromus inerrnis Leyss. Aboveground biomass of the 3 grass species grown in mixture with Centaurea was compared to growth in monoculture at a range of nitrogen input levels. The results suggest that Bromus is capable of suppressing the growth of Centaurea with the degree of suppression increasing with increasing nitrogen levels. The 2 native grasses had no impact on Centaurea …

Evaluation Of The Crop Growth Component Of The Root Zone Water Quality Model For Corn In Ohio, Sue E. Nokes, Feliks M. Landa, Jon D. Hanson

Biosystems and Agricultural Engineering Faculty Publications

The Root Zone Water Quality Model (RZWQM) is a computer model developed to simulate water, chemical, and biological processes in the root zone of agricultural management systems. As of this writing RZWQM is in the beta-testing phase of development. This article reports on a parameterization and evaluation study performed in Ohio on field corn for the crop growth component of RZWQM. The generic crop growth model in RZWQM had not previously been parameterized or tested on field corn. This article reports the results of such a study. One year of data was used to calibrate RZWQM, and two additional years …

Comparison Of Daily Water Table Depth Prediction By Four Simulation Models, Eric D. Desmond, Andrew D. Ward, Norman R. Fausey, Stephen R. Workman

Biosystems and Agricultural Engineering Faculty Publications

The Agricultural Drainage And Pesticide Transport (ADAPT) model was compared to the water management simulation models DRAINMOD, SWATREN, and PREFLO. SWATREN and PREFLO are one-dimensional finite-difference models while ADAPT and DRAINMOD are one-dimensional mass balance models. ADAPT, an extension of the computer model GLEAMS, also provides chemical transport information. All four models were tested against field data from Aurora, North Carolina. Observed water table depth data were collected during 1973 through 1977 from a water table management field experiment with three subsurface drain spacing treatments of 7.5, 15, and 30 m.

Both the standard error of estimate and the average …

Baccharis Malibuensis (Asteraceae): A New Species From The Santa Monica Mountains, California, R. Mitchell Beauchamp, James Henrickson

Aliso: A Journal of Systematic and Floristic Botany

Baccharis malibuensis is described from the Malibu Lake region of the Santa Monica Mountains, Los Angeles County, California. It is closely related to Baccharis plummerae subsp. plummerae but differs in having narrow, subentire, typically conduplicate, sparsely villous to mostly glabrous leaves with glands occurring in depressions on the adaxial surface, more cylindrical inflorescences, and a distribution in open chaparral vegetation. The new taxon shares some characteristics with B. plummerae subsp. glabrata of northwestern San Luis Obispo County, e.g., smaller leaves, reduced vestiture, and occurrence in scrub habitat, but the two taxa appear to have developed independently from B. p. subsp. …

Crossroads, Milestones, Amd Landmarks In Insect Development And Evolution: Implications For Systematics, Rob Desalle, Donat Agosti, Michael Whiting, Beatriz Perez-Sweeney, James Remsen, Rick Baker, James Bonacum, Ranhy Bang

Aliso: A Journal of Systematic and Floristic Botany

Our understanding of insect development and evolution has increased greatly due to recent advances in the comparative developmental approach. Modem developmental biology techniques such as in situ hybridization and molecular analysis of developmentally important genes and gene families have greatly facilitated these advances. The role of the comparative developmental approach in insect systematics is explored in this paper and we suggest two important applications of the approach to insect systematics--character dissection and morphologicallandmarking. Exi~ng morphological characters can be dissected into their genetic and molecular components in some cases and this will lead to more and richer character information in systematic …

Studies In Macrosiphonia (Apocynaceae): Generic Recognition Of Telosiphonia, James Henrickson

Aliso: A Journal of Systematic and Floristic Botany

Woodson recognized two subgenera within Macrosiphonia (Apocynaceae: Apocynoideae), a South American subgenus Eumacrosiphonia, and a North American subgenus Telosiphonia each with five species. Both taxa are characterized by low subshrub-shrub, nonviny growth habits, white, long-tubed, vespertine corollas of a type associated with moth pollination. Their distinctive anther and style-tip characteristics show each is related to a group of genera around Mandevilla and Mesechites. The two subgenera, however, differ strongly from each other in inflorescence, style-head structure, and pollen size indicating that they are not sister taxa and that Macrosiphonia as currently recognized is polyphyletic. Thus the subgenus Telosiphonia …

Integrating Cellular And Molecular Approchaes Into Studies Of Development And Evolution: The Issue Of Morphological Homology, Andrés Collazo, Scott E. Fraser

Aliso: A Journal of Systematic and Floristic Botany

Understanding the development and evolution of complex morphological characters requires broad, multidisciplinary approaches. By combining biological imaging, phylogenetic analyses, embryological manipulations and additional modem molecular techniques (e.g., whole mount in situ hybridization), we can address fundamental questions, such as the determination of homology. Many of the novel structures that evolved in vertebrates and distinguish them from their ancestors (such as jaws and the mechanosensory lateral line) are derived embryonically from two migratory ectodermal tissues, neural crest and/or various epidermal placodes. In particular, time-lapse cinematography of fluorescently labeled cells in living Xenopus and fish embryos has proved a powerful technique, revealing …

Options For Pest Management In Pastures, Phil Michael, Mike Grimm, Mike Hyder, Peter Doyle

Journal of the Department of Agriculture, Western Australia, Series 4

Redlegged eath mit, blue oat ite, lucern flea and aphids damage pastures across southern Australia, and it has been estimated that they cause annual losses to the Australian wool industry alone of over $200 million.

Redlegged earth mite is without doubt the most serious of the four pests. Peter DoPhil Michael, Mike Grimm, Mike Hyder and Peter Doyle discuss intergrated management options to control these pests.

Stand Hazard Rating For Central Idaho Forests, Robert Steele, Ralph E. Williams, Julie C. Weatherby, Elizabeth D. Reinhardt, James T. Hoffman, R. W. Thier

Aspen Bibliography

No abstract provided.

Fire-Bgc--A Mechanistic Ecological Process Model For Simulating Fire Succession On Coniferous Forest Landscapes Of The Northern Rocky Mountains, Robert E. Keane, Penelope Morgan, Steven W. Running

Aspen Bibliography

An ecological process model of vegetation dynamics mechanistically simulates long-term stand dynamics on coniferous landscapes of the Northern Rocky Mountains. This model is used to investigate and evaluate cumulative effects of various fire regimes, including prescribed burning and fire exclusion, on the vegetation and fuel complex of a simulation landscape composed of many stands. Detailed documentation of the model FIRE-BGC (a FIRE BioGeoChemical succession model) with complete discussion of all model parameters is followed with results of an application of the FIRE-BGC to a whitebark pine landscape in the Bob Marshall Wilderness Complex. Simulation results of several management scenarios are …

Waste-Wood-Derived Fillers For Plastics, Brent English, Craig M. Clemons, Nicole Stark, James P. Schneider

Aspen Bibliography

Filled thermoplastic composites are stiffer, stronger, and more dimensionally stable than their unfilled counterparts. Such thermoplastics are usually provided to the end-user as a precompounded, pelletized feedstock. Typical reinforcing fillers are inorganic materials like talc or fiberglass, but materials derived from waste wood, such as wood flour and recycled paper fiber, are also effective as fillers. The goal of this project was to generate commercial interest in using waste-wood–paper-derived fillers (WPFs) to reinforce thermoplastics. The research strategy was twofold: developmental research and outreach. Specific objectives were (1) to improve wastepaper fiber preparation, feeding, and compounding methods, and optimize composite performance, …

The Complete Nucleotide Sequence And Genome Organization Of The M Rna Segment Of Peanut Bud Necrosis Tospovirus And Comparison With Other Tospoviruses, Satyanarayana Tatineni, S. E. Mitchell, D. V. R. Reddy, S. Kresovich, R. Jarret, R. A. Naidu, S. Gowda, J. W. Demski

Department of Plant Pathology: Faculty Publications

The M RNA of peanut bud necrosis virus (PBNV; synonym groundnut bud necrosis virus) is 4801 nucleotides in length. It comprised two ORFs in an ambisense organization and terminal inverted repeats. The 3' large ORF (3363 nucleotides in the virus-complementary strand) encoded a protein with a predicted size of 127.2 kDa which was identified as the glycoprotein precursor (GP) of the G1 and G2 glycoproteins. A comparison of the deduced amino acid sequence of GP revealed 37 % identity and 58-59% similarity with that of tomato spotted wilt virus (TSWV, serogroup I) and impatiens necrotic spot virus (INSV, serogroup III), …

Peanut Bud Necrosis Virus: Purification Of Nucleocapsids And Sequence Homology Of Nucleocapsid Protein And Glycoprotein Precursor With Other Tospoviruses, Satyanarayana Tatineni, S. E. Mitchell, D. V. R. Reddy, S. Brown, S. Kresovich, R. Jarret, S. Gowda, R. A. Naidu, J. W. Demski

Department of Plant Pathology: Faculty Publications

A procedure for the purification of peanut bud necrosis virus (PBNV) nucleocapsids was developed. Virus particles were treated with nonionic detergent to disrupt the envelope membrane and free nucleocapsids were separated. into three lightscattering zones after sucrose gradient centrifogation. Nucleocapsids from the top zone contained S RNA and traces ofM RNA; whereas, nucleoplasids from the middle zone contained M RNA with detectable levels of S RNA and those from the bottom zone contained L RNA with traces of M and S RNAs. Clones from a cDNA library made from the purified PBNV Sand M RNAs were characterized and sequenced. Comparison …

Diagnosis And Resistance Breeding Of Peanut Bud Necrosis Virus, D. V. R. Reddy, Satyanarayana Tatineni, S. L. Dwivedi, A. S. Ratna, A. A. M. Buiel, G. V. Ranga Rao, S. N. Nigam, R. A. Naidu, H. T. Hsu, J. W. Demski

Department of Plant Pathology: Faculty Publications

The occu!fence of peanut bud necrosis (PBN) disease in India was first reported in 1968. The high incidence ofPBN disease during the 1960s coincided with largescale imports of the peanut cultivars Asiria Mwitundae and Spanish Improved, both of which are highly susceptible to PBN. Since then, a number of reports have been published in India describing bud necrosis under at least seven different names (Reddy 1988). Crop losses due to PBN have been estimated at USD89 million per year in India during 1976-1986. The disease is also currently recognized as economically important in Nepal (Sharma 1996), in Sri Lanka, and …

Fumonisins And Alternaria Alternata Lycopersici Toxins: Sphinganine Analog Mycotoxins Induce Apoptosis In Monkey Kidney Cells, Hong Wang, Clinton Jones, Janice Caiacci-Zanella, Todd Holt, David G. Gilchrist, Martin B. Dickman

Department of Plant Pathology: Faculty Publications

Fusarium moniliforme toxins (fumonisins) and Alternaria alternata lycopersici (AAL) toxins are members of a new class of sphinganine analog mycotoxins that occur widely in the food chain. These mycotoxins represent a serious threat to human and animal health, inducing both cell death and neoplastic events in mammals. The mechanisms by which this family of chemical congeners induce changes in cell homeostasis were investigated in African green monkey kidney cells (CV-1) by assessing the appearance of apoptosis, cell cycle regulation, and putative components of signal transduction pathways involved in apoptosis. Structurally, these mycotoxins resemble the sphingoid bases, sphingosine and sphinganine, that …

A Revision Of Discocarpus (Euphorbiaceae), Sheila M. Hayden, W. John Hayden

Biology Faculty Publications

As revised here, Discocarpus is interpreted to consist of three neotropical species: D. essequeboensis Klotzsch, D. gentryi S. M. Hayden, which is described and named herein as new to science, and D. spruceanus Müll. Arg. One previously accepted name, D. brasiliensis Klotzsch ex Müll. Arg., is reduced to synonymy of D. essequeboensis. Lecto-types are proposed for the two species previously described. One species is newly excluded from Discocarpus, as are three others, following previous literature. Foliar anatomy is described with a focus on epidermal sclereids, which are shown to occur on both epidermides. Evidence presented supports close relationships …