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2c Dna Content Values In Amaranthus (Amaranthaceae) [Abstract], Donald B. Pratt, Shalini N. Jhangiani, Robert J. Wiggers Jan 2008

2c Dna Content Values In Amaranthus (Amaranthaceae) [Abstract], Donald B. Pratt, Shalini N. Jhangiani, Robert J. Wiggers

Faculty Publications

No abstract provided.


Development And Characterization Of Microsatellite Markers For The Grain Amaranths [Abstract], Melanie A. Mallory, Rozaura V. Hall, Andrea R. Mcnabb, Donald B. Pratt, Eric N. Jellen, Peter J. Maughan Jan 2008

Development And Characterization Of Microsatellite Markers For The Grain Amaranths [Abstract], Melanie A. Mallory, Rozaura V. Hall, Andrea R. Mcnabb, Donald B. Pratt, Eric N. Jellen, Peter J. Maughan

Faculty Publications

No abstract provided.


Comparison Of Plant Growth-Promotion With Pseudomonas Aeruginosa And Bacillus Subtilis In Three Vegetables, A. O. Adesemoye, M. Obini, E. O. Ugoji Jan 2008

Comparison Of Plant Growth-Promotion With Pseudomonas Aeruginosa And Bacillus Subtilis In Three Vegetables, A. O. Adesemoye, M. Obini, E. O. Ugoji

Department of Plant Pathology: Faculty Publications

Our objective was to compare some plant growth-promoting rhizobacteria (PGPR) properties of Bacillus subtilis and Pseudomonas aeruginosa as representatives of their two genera. Solanum lycopersicum L. (tomato), Abelmoschus esculentus (okra), and Amaranthus sp. (African spinach) were inoculated with the bacterial cultures. At 60 days after planting, dry biomass for plants treated with B. subtilis and P. aeruginosa increased 31% for tomato, 36% and 29% for okra, and 83% and 40% for African spinach respectively over the non-bacterized control. Considering all the parameters tested, there were similarities but no significant difference at P < 0.05 between the overall performances of the two organisms.


Algae In Agricultural Fields From St. Francis County, Arkansas, T. Smith Jan 2008

Algae In Agricultural Fields From St. Francis County, Arkansas, T. Smith

Journal of the Arkansas Academy of Science

On August 9th, 2007, two agriculture fields (rice and sorghum fields) were sampled for freshwater algae in St. Francis County. The purpose of this study was to document the algal species in the rice and sorghum fields and compare the similarities of species composition. There were a total of 53 species identified. Overall, diatoms and cyanobacteria were equally dominant with both represented by 21 species (39.6% of the total) and 11 green algal species (20.8%) were present. The sorghum field was dominated by Chlorogloeopsis fritschii and Chroococcus limneticus, while Anabeana cylindrica was abundant in the rice field.


The Small Glycine-Rich Rna Binding Protein Atgrp7 Promotes Floral Transition In Arabidopsis Thaliana, Corinna Streitner, Selahattin Danisman, Franziska Wehrle, Jan C. Schoning, James R. Alfano, Dorothee Staiger Jan 2008

The Small Glycine-Rich Rna Binding Protein Atgrp7 Promotes Floral Transition In Arabidopsis Thaliana, Corinna Streitner, Selahattin Danisman, Franziska Wehrle, Jan C. Schoning, James R. Alfano, Dorothee Staiger

Center for Plant Science Innovation: Faculty Publications

The RNA binding protein AtGRP7 is part of a circadian slave oscillator in Arabidopsis thaliana that negatively autoregulates its own mRNA, and affects the levels of other transcripts. Here, we identify a novel role for AtGRP7 as a flowering-time gene. An atgrp7-1 T-DNA mutant flowers later than wild-type plants under both long and short days, and independent RNA interference lines with reduced levels of AtGRP7, and the closely related AtGRP8 protein, are also late flowering, particularly in short photoperiods. Consistent with the retention of a photoperiodic response, the transcript encoding the key photoperiodic regulator CONSTANS oscillates with a similar pattern …


New And Current Microbiological Tools For Ecosystem Ecologists: Towards A Goal Of Linking Structure And Function, Rebecca E. Drenovsky, Kevin P. Ferris, Katharine M. Batten, Krassimira Hristova Jan 2008

New And Current Microbiological Tools For Ecosystem Ecologists: Towards A Goal Of Linking Structure And Function, Rebecca E. Drenovsky, Kevin P. Ferris, Katharine M. Batten, Krassimira Hristova

Biology

Interest in the relationships between soil microbial communities and ecosystem functions is growing with increasing recognition of the key roles microorganisms play in a variety of ecosystems. With a wealth of microbial methods now available, selecting the most appropriate method can be daunting, especially to those new to the field of microbial ecology. In this review, we highlight those methods currently used and most applicable to ecological studies, including assays to study various aspects of the carbon and nitrogen cycles (e.g., pool dilution, acetylene reduction, enzyme analyses, among others), methods to assess microbial community composition (e.g., phospholipid fatty acid analysis …


Mullewa Research Annexe Spring Field Day Future Farming Systems For North-Eastern Districts 21 August 2008, Department Of Agriculture, Western Australia Jan 2008

Mullewa Research Annexe Spring Field Day Future Farming Systems For North-Eastern Districts 21 August 2008, Department Of Agriculture, Western Australia

Grain and other field crops research reports

Papers:

  • Mullewa Research Annexe activities 2008

  • Wheat for today and the future

  • Consequences of strongly acidic and alkaline soils

  • Break crop influence on low rainfall heavy soil

  • Chemical fallow options for the north-east agricultural region

  • Herbicide tolerance of new wheat varieties

  • Lowrainfall oilseed crops for food and biofuel

  • Utilising stock to reduce business risk in Binnu! A case study


Spiderwort Is Vnps Wildflower Of The Year, W. John Hayden Jan 2008

Spiderwort Is Vnps Wildflower Of The Year, W. John Hayden

Biology Faculty Publications

The VNPS 2008 Wildflower of the Year (WOY) is spiderwort (Tradescantia virginiana). This herbaceous perennial plant occurs throughout much of the eastern portion of the U.S. and is widespread in Virginia. Spiderwort blooms from April to July. The small flowers occur in clusters at the ends of the stems, atop several elongate bracts. Flowers have three petals that range from purple to rose or, rarely, white. Densely hairy stamens provide, perhaps, the easiest way to recognize spiderworts. Also, stalks of spent flowers droop below the flower cluster yielding an aspect reminiscent of spindly spider legs.


In Planta Distribution Of ‘Candidatus Liberibacter Asiaticus’ As Revealed By Polymerase Chain Reaction (Pcr) And Real-Time Pcr, Satyanarayana Tatineni, Uma Shankar Sagaram, Siddarame Gowda, Cecile J. Robertson, William O. Dawson, Toru Iwanami, Nian Wang Jan 2008

In Planta Distribution Of ‘Candidatus Liberibacter Asiaticus’ As Revealed By Polymerase Chain Reaction (Pcr) And Real-Time Pcr, Satyanarayana Tatineni, Uma Shankar Sagaram, Siddarame Gowda, Cecile J. Robertson, William O. Dawson, Toru Iwanami, Nian Wang

Department of Plant Pathology: Faculty Publications

Huanglongbing (HLB) is one of the most devastating diseases of citrus worldwide, and is caused by a phloem-limited fastidious prokaryotic α- proteobacterium that is yet to be cultured. In this study, a combination of traditional polymerase chain reaction (PCR) and real-time PCR targeting the putative DNA polymerase and 16S rDNA sequence of ‘Candidatus Liberibacter asiaticus,’ respectively, were used to examine the distribution and movement of the HLB pathogen in the infected citrus tree. We found that ‘Ca. Liberibacter asiaticus’ was distributed in bark tissue, leaf midrib, roots, and different floral and fruit parts, but not in endosperm and …


Three Genes Of Citrus Tristeza Virus Are Dispensable For Infection And Movement Throughout Some Varieties Of Citrus Trees, Satyanarayana Tatineni, Cecile J. Robertson, Stephen M. Garnsey, Moshe Bar-Joseph, Siddarame Gowda, William O. Dawson Jan 2008

Three Genes Of Citrus Tristeza Virus Are Dispensable For Infection And Movement Throughout Some Varieties Of Citrus Trees, Satyanarayana Tatineni, Cecile J. Robertson, Stephen M. Garnsey, Moshe Bar-Joseph, Siddarame Gowda, William O. Dawson

Department of Plant Pathology: Faculty Publications

Citrus tristeza virus (CTV), a member of the Closteroviridae, possesses a 19.3-kb positive-stranded RNA genome that is organized into twelve open reading frames (ORFs). The CTV genome contains two sets of conserved genes, which are characteristic of this virus group, the replication gene block (ORF 1a and 1b) and the quintuple gene block (p6, HSP70 h, p61, CPm, and CP). With the exception of the p6 gene, they are required for replication and virion assembly. CTV contains five additional genes, p33, p18, p13, p20 and p23, in the 3′ half of the genome, some of which (p33, p18 and …


Regulation Of Apical Dominance In Aspergillus Nidulans Hyphae By Reactive Oxygen Species, Camile P. Semighini, Steven D. Harris Jan 2008

Regulation Of Apical Dominance In Aspergillus Nidulans Hyphae By Reactive Oxygen Species, Camile P. Semighini, Steven D. Harris

Department of Plant Pathology: Faculty Publications

In fungal hyphae, apical dominance refers to the suppression of secondary polarity axes in the general vicinity of a growing hyphal tip. The mechanisms underlying apical dominance remain largely undefined, although calcium signaling may play a role. Here, we describe the localized accumulation of reactive oxygen species (ROS) in the apical region of Aspergillus nidulans hyphae. Our analysis of atmA (ATM) and prpA (PARP) mutants reveals a correlation between localized production of ROS and enforcement of apical dominance. We also provide evidence that NADPH oxidase (Nox) or related flavoproteins are responsible for the generation of ROS at hyphal tips and …


An Immunofluorescence Assay To Detect Urediniospores Of Phakopsora Pachyrhizi, Fulya Baysal-Gurel, Melanie L. Lewis Ivey, Anne E. Dorrance, Douglas Luster, Reid Frederick, Jill Czarnecki, Michael J. Boehm, Sally A. Miller Jan 2008

An Immunofluorescence Assay To Detect Urediniospores Of Phakopsora Pachyrhizi, Fulya Baysal-Gurel, Melanie L. Lewis Ivey, Anne E. Dorrance, Douglas Luster, Reid Frederick, Jill Czarnecki, Michael J. Boehm, Sally A. Miller

Department of Plant Pathology: Faculty Publications

An indirect immunofluorescence spore assay (IFSA) was developed to detect urediniospores of Phakopsora pachyrhizi, utilizing rabbit polyclonal antisera produced in response to intact nongerminated (SBR1A) or germinated (SBR2) urediniospores of P. pachyrhizi. Both antisera were specific to Phakopsora spp. and did not react with other common soybean pathogens or healthy soybean leaf tissue in enzyme-linked immunosorbent assay (ELISA). SBR1A and SBR2 bound to P. pachyrhizi and P. meibomiae urediniospores were detected with goat anti-rabbit Alexa Fluor 488-tagged antiserum using a Leica DM IRB epifluorescent microscope with an I3 blue filter (excitation 450 to 490 nm, emission 515 nm). The …


2008 Wildflower Of The Year: Virginia Spiderwort, Tradescantia Virginiana, W. John Hayden Jan 2008

2008 Wildflower Of The Year: Virginia Spiderwort, Tradescantia Virginiana, W. John Hayden

Biology Faculty Publications

Spiderwort is an herbaceous perennial that arises from a cluster of rather stout overwintering roots. Stems may be solitary or more commonly clumped, and usually grow unbranched, reaching heights up to 40 cm tall. Stems are smooth or bear scattered short hairs. Leaves are 2—5 per stem, attached by means of a leaf sheath that is 13 cm long. Leaf blades are dull green, elongate, ending in a gradually tapered tip, flat or keeled, smooth (without hairs), and 1—3.5 dm long by 0.5—2.5 cm wide. Flowers occur in tight clusters located at the stem apex; bracts similar to the leaves …


State Of The River Report For The Lower St. Johns River Basin, Florida: Water Quality, Fisheries, Aquatic Life, And Contaminants 2008, Environmental Protection Board, City Of Jacksonville, University Of North Florida, Jacksonville University Jan 2008

State Of The River Report For The Lower St. Johns River Basin, Florida: Water Quality, Fisheries, Aquatic Life, And Contaminants 2008, Environmental Protection Board, City Of Jacksonville, University Of North Florida, Jacksonville University

State of the River Report

No abstract provided.


Microspore Wall Morphogenesis And Orbicule Ultrastructure Of Isoetes, Khalid Alarid Jan 2008

Microspore Wall Morphogenesis And Orbicule Ultrastructure Of Isoetes, Khalid Alarid

Biological Sciences Theses & Dissertations

The microspore wall morphogenesis and orbicule ultrastructure of Isoetes were studied using electron microscopy. Microspore wall morphogenesis in five species of Isoetes (I. appalachiana, I. engelmannii, I. hyemalis, I. piedmontana, and an undescribed species from York Co., VA, USA) was studied using scanning and transmission electron microscopy. Results show that they generally have the same developmental stages in terms of microspore wall morphogenesis. The mature microspore wall consisted of four layers: perispore, paraexospore, exospore and endospore. Paraexospore formation began during the tetrad stage. The exospore was then formed between the paraexospore and the plasma membrane. During the free spore …


Virulence Diversity Of The Common Bean Rust Pathogen Within And Among Individual Bean Fields And Development Of Sampling Strategies, C. Jochua, M. I. V. Amane, J. R. Steadman, X. Xue, K. M. Eskidge Jan 2008

Virulence Diversity Of The Common Bean Rust Pathogen Within And Among Individual Bean Fields And Development Of Sampling Strategies, C. Jochua, M. I. V. Amane, J. R. Steadman, X. Xue, K. M. Eskidge

Department of Plant Pathology: Faculty Publications

There is a dearth of information on pathogen variation within an individual field. In this study, virulence diversity of Uromyces appendiculatus, cause of bean rust, within individual fields was investigated. From six bean fields in the United States, Honduras, Dominican Republic, and South Africa, 380 U. appendiculatus isolates were differentiated into 65 virulence phenotypes on bean lines containing Andean- and Middle American-derived rust resistance genes. Race variation among bean rust isolates from different geographic regions was found, and virulence phenotypes found in fields from tropical and subtropical regions were more virulent and diverse than those found in fields from …


Branching Of Fungal Hyphae: Regulation, Mechanisms And Comparison With Other Branching Systems, Steven D. Harris Jan 2008

Branching Of Fungal Hyphae: Regulation, Mechanisms And Comparison With Other Branching Systems, Steven D. Harris

Department of Plant Pathology: Faculty Publications

The ability of rapidly growing hyphae to generate new polarity axes that result in the formation of a branch represents one of the most important yet least understood aspects of fungal cell biology. Branching is central to the development of mycelial colonies and also appears to play a key role in fungal interactions with other organisms. This review presents a description of the two major patterns of hyphal branching, apical and lateral, and highlights the roles of internal and external factors in the induction of branch formation. In addition, potential mechanisms underlying branch site selection are outlined, and the possible …


First Report Of Annual Bluegrass Weevil, Listronotus Maculicollis, Damage In Ohio, John L. Koenig, David J. Shetlar, Joseph W. Rimelspach, Michael J. Boehm Jan 2008

First Report Of Annual Bluegrass Weevil, Listronotus Maculicollis, Damage In Ohio, John L. Koenig, David J. Shetlar, Joseph W. Rimelspach, Michael J. Boehm

Department of Plant Pathology: Faculty Publications

Annual bluegrass weevil [Listronotus maculicollis (Kirby) (1)] larvae, pupae, and adults were recovered and identified in a sample received by the C. Wayne Ellett Plant and Pest Diagnostic Clinic (CWEPPDC) at Ohio State University on 19 June 2007. Damage to the approaches and collars of four golf course putting greens was detected by the superintendent of Stonewater Golf Club, Highland Heights, OH (a suburb of Cleveland) during the week of 11 June 2007. The superintendent suspected damage from the larvae of the black turfgrass ataenius, Ataenius spretulus (1). Insecticide applications applied to suppress black turfgrass ataenius did not provide …


Rapid Development Of Fungicide Resistance By Sclerotinia Homoeocarpa On Turfgrass, Young-Ki Jo, Seog Won Chang, Michael J. Boehm, Geunhwa Jung Jan 2008

Rapid Development Of Fungicide Resistance By Sclerotinia Homoeocarpa On Turfgrass, Young-Ki Jo, Seog Won Chang, Michael J. Boehm, Geunhwa Jung

Department of Plant Pathology: Faculty Publications

Dollar spot, caused by Sclerotinia homoeocarpa, is the most prevalent and economically important turfgrass disease in North America. Increasing levels of fungicide resistance, coupled with tightening environmental scrutiny of existing fungicides, has left fewer options for managing dollar spot. More knowledge about S. homoeocarpa populations is needed to improve dollar spot management strategies, especially with respect to minimizing the development of fungicide resistance. Population diversity of S. homoeocarpa was examined using inter-simple sequence repeat markers and vegetative compatibility assays. Two subgroups were found in S. homoeocarpa field populations on both fairway and putting green turfgrass at a research field …


Inoculation Strategies To Assess Biological Interactions Between Fusarium And Alternaria Species Infecting Sorghum, Deanna L. Funnell-Harris, Jeffrey F. Pedersen Jan 2008

Inoculation Strategies To Assess Biological Interactions Between Fusarium And Alternaria Species Infecting Sorghum, Deanna L. Funnell-Harris, Jeffrey F. Pedersen

Department of Plant Pathology: Faculty Publications

New cultivars of sorghum are being developed for increased food use, as livestock feed, and for the bioenergy industry by manipulation of secondary metabolic pathways through breeding. Previous work has suggested that such modifications may have an impact on cultivar response to fungal pathogens. We investigated four inoculation strategies that may be used in studies involving pathogens of sorghum. Plants of elite sorghum genotypes ‘Wheatland’ and RTx430, commonly used in breeding programs, were inoculated with isolates of Alternaria alternata, Fusarium equiseti, Fusarium proliferatum, Fusarium solani, Fusarium thapsinum, and Fusarium verticillioides recovered from field-grown sorghum. Wound inoculation of the peduncles …


Whole-Plant Mineral Partitioning Throughout The Life Cycle In Arabidopsis Thaliana Ecotypes Columbia, Landsberg Erecta, Cape Verde Islands, And The Mutant Line Ysl1ysl3, Brian M. Waters, Michael A. Grusak Jan 2008

Whole-Plant Mineral Partitioning Throughout The Life Cycle In Arabidopsis Thaliana Ecotypes Columbia, Landsberg Erecta, Cape Verde Islands, And The Mutant Line Ysl1ysl3, Brian M. Waters, Michael A. Grusak

Department of Agronomy and Horticulture: Faculty Publications

Minimal information exists on whole-plant dynamics of mineral flow through Arabidopsis thaliana or on the source tissues responsible for mineral export to developing seeds. Understanding these phenomena in a model plant could help in the development of nutritionally enhanced crop cultivars. A whole-plant partitioning study, using sequential harvests, was conducted to characterize growth and mineral concentrations and contents of rosettes, cauline leaves, stems, immature fruit, mature fruit hulls, and seeds of three WT lines (Col-0, Ler, and Cvi) and one mutant line (Col-0::ysl1ysl3). Shoot mineral content increased throughout the life cycle for all minerals, although tissue-specific …


Registration Of ‘Darrell’ Wheat, A. M. H. Ibrahim, S. D. Haley, P. S. Baenziger, Y. Jin, M. A. C. Langham, J. Rickertsen, S. Kalsbeck, R. Little, J. Ingemansen, O. K. Chung, B. W. Seabourn, G. H. Bai, Ming-Shun Chen, D. V. Mcvey Jan 2008

Registration Of ‘Darrell’ Wheat, A. M. H. Ibrahim, S. D. Haley, P. S. Baenziger, Y. Jin, M. A. C. Langham, J. Rickertsen, S. Kalsbeck, R. Little, J. Ingemansen, O. K. Chung, B. W. Seabourn, G. H. Bai, Ming-Shun Chen, D. V. Mcvey

Department of Agronomy and Horticulture: Faculty Publications

‘Darrell’ (Reg. No. CV-1024, PI 644224) hard red winter wheat (Triticum aestivum L.) was developed by the South Dakota State University–Agricultural Experiment Station and released in 2006 to seed producers by the South Dakota State University–Agricultural Experiment Station and the University of Nebraska Agricultural Experiment Station. Darrell was selected from the cross 2076-W12-11/‘Karl 92’ (PI 564245)//NE89526. NE89526 is an experimental line from the University of Nebraska with the pedigree ‘Lancota’ (CI 17389) selection/’Siouxland’ (PI 483469)//TX792729. 2076-W12-11 is an unreleased experimental line that originated from a population with an unidentified pedigree. Darrell was selected as an F3:4 line in 1998 …


Anther Appendages Of Incarvillea Trigger A Pollen-Dispensing Mechanism, Yi Han, Can Dai, Chun-Feng Yang, Qing-Feng Wang, Timothy J. Motley Jan 2008

Anther Appendages Of Incarvillea Trigger A Pollen-Dispensing Mechanism, Yi Han, Can Dai, Chun-Feng Yang, Qing-Feng Wang, Timothy J. Motley

Biological Sciences Faculty Publications

Background and Aims Anther appendages play diverse roles in anther dehiscence and pollen dispersal. This study aims to explore the pollen-dispensing mechanism triggered by special anther appendages in Incarvillea arguta.

Methods Field studies were conducted to record floral characteristics, pollinator visitations, and flower-pollinator interactions. Measurements of flowers and pollinators were analysed statistically. Pollen counts following a series of floral manipulations were used to evaluate pollen dispensing efficiency and function of the anther appendages.

Key Results Field observations determined that two species of Bombus (bumble-bees) were the primary pollinators of I. arguta with a mean visiting frequency of 1.42 visitations …


Quantitative-Genetic Variation In Morphological And Physiological Traits Within A Quaking Aspen (Populus Tremuloides) Population, Megan K. Kanaga, Ronald J. Ryel, Karen E. Mock, Michael E. Pfrender Jan 2008

Quantitative-Genetic Variation In Morphological And Physiological Traits Within A Quaking Aspen (Populus Tremuloides) Population, Megan K. Kanaga, Ronald J. Ryel, Karen E. Mock, Michael E. Pfrender

Wildland Resources Faculty Publications

Genetic diversity within populations is an important component of adaptive evolution, and recent research has demonstrated that genetic variation within plant populations can have important ecological effects. In this study, we investigate quantitative-genetic variation in several traits within a quaking aspen (Populus tremuloides Michx.) population. A common garden experiment was planted with replicates of 13 aspen genotypes collected from wet and dry sites within a population in southern Utah, USA. Ten growth, leaf, physiological, and structural traits were measured. There were significant, heritable phenotypic differences among genotypes in every measured trait and differences in 4 of the 10 traits among …


Joint Fire Science Program – Lake Mead National Recreation Area: Revegetating Burned Arid Lands: Identifying Successful Native Species Using Trait And Competition Analysis, Quarterly Progress Report, October 1, 2007 To December 31, 2007, Margaret N. Rees Dec 2007

Joint Fire Science Program – Lake Mead National Recreation Area: Revegetating Burned Arid Lands: Identifying Successful Native Species Using Trait And Competition Analysis, Quarterly Progress Report, October 1, 2007 To December 31, 2007, Margaret N. Rees

Fire Science

The task agreement was awarded to UNLV on October 1, 2007. This report covers the period October 1, 2007 to December 31, 2007. The following activities have been conducted toward meeting or exceeding deliverables in the statement of work: hiring and project start and experimental set-up


An Assessment Of Methods For Sampling Carabid Beetles (Coleptera: Carabidae) In A Montane Rain Forest, B. A. Nyundo, J. G. Yarro Dec 2007

An Assessment Of Methods For Sampling Carabid Beetles (Coleptera: Carabidae) In A Montane Rain Forest, B. A. Nyundo, J. G. Yarro

Tanzania Journal of Science

Pitfall trapping is the traditional method for sampling carabid beetles and other grounddwelling invertebrates. Tests were carried out in the Udzungwa Mountains National Park between March 1999 and July 2000. Results indicated that pitfall traps were less efficient compared to manual searching methods, both in terms of relative abundance and species richness of carabid beetles. The results are discussed in the context of biodiversity inventories in theEastern Arc Mountains.


Impact Of Small Scale Gold Mining On Soils Of The Wetland Forests In East Usambara, Tanzania, C. Kweyunga, R. B. M. Rbm Senzota Dec 2007

Impact Of Small Scale Gold Mining On Soils Of The Wetland Forests In East Usambara, Tanzania, C. Kweyunga, R. B. M. Rbm Senzota

Tanzania Journal of Science

Soil pits in disturbed and natural wetland forests of East Usambara were excavated and soil profile samples collected and analysed for physical and chemical properties. Their physical and chemical characteristics were found to be sharply different from those of the surrounding hills. Differences included lack of A Horizon, water saturation, presence of very high organic matter, very low pH and hence very poor in basic cations, and low microbial activity. Nutrient recycling, especially nitrogen and phosphorus, tended to shift from mineralization to immobilization. Effects of soil disturbance on both physical and chemical characteristics of the soils were also very vivid. …


Enhancing The Ability Of Panicum Virgatum To Survive Flooding And Its Effects On Soil Activity When Used For Lakeshore Stabilization, Lee Edwards Dec 2007

Enhancing The Ability Of Panicum Virgatum To Survive Flooding And Its Effects On Soil Activity When Used For Lakeshore Stabilization, Lee Edwards

All Dissertations

Reservoirs in upstate South Carolina are subject to erosion and vegetation has been placed to help stabilize banks, but soils are nutrient-poor and have high bulk densities. Panicum virgatum L. (switchgrass) has been planted in several sites, and it is hypothesized that over time, changes in microbial activity and soil quality will occur in response to the planting. As vegetated sites aged, acid phosphomonoesterase, nitrate reductase, and dehydrogenase activity increased. Low values of nitrogen fixation and substrate-induced respiration were measured at all sites with no statistical differences between sites. Fatty acids indicative of Gram negative bacteria were found in vegetated …


Maestra2: A Model For Simulating Spatially Explicit Carbon Dioxide Exchange Rates Among Species' Water Stress Response, Robert Reynolds Dec 2007

Maestra2: A Model For Simulating Spatially Explicit Carbon Dioxide Exchange Rates Among Species' Water Stress Response, Robert Reynolds

All Theses

MAESTRA2, a species specific mechanistic model, was parameterized to estimate water use, carbon accumulation and organ specific respiration of five deciduous tree species under both irrigated and water stressed conditions. The model was validated using temporally and spatially explicit ecophysiological data to account for seasonal changes in species physiology. The following tree species: Acer rubrum L. 'Summer Red' (A. rubrum), Betula nigra (B. nigra), Paulownia elongata (P. elongata), Quercus nuttallii (Q. nuttallii), and Quercus phellos (Q. phellos) were intensively measured and organ specific destructively harvested samples were compared to modeled estimates of carbon accumulation. Among species, we observed variability in …


The Jeweled Armor Of Tillandsia—Multifaceted Or Elongated Trichomes Provide Photoprotection, Simon Pierce Dec 2007

The Jeweled Armor Of Tillandsia—Multifaceted Or Elongated Trichomes Provide Photoprotection, Simon Pierce

Aliso: A Journal of Systematic and Floristic Botany

Foliar trichomes of gray-leaved Tillandsioideae (Bromeliaceae) are highly reflective, suggesting a role in protecting the leaf against direct sunlight in exposed niches. The performance of photosystem II, as denoted by the chlorophyll fluorescence characteristic Fv /Fm , was determined for seven Tillandsia species and Vriesea barclayana that were exposed to excessive light, with trichomes either present or removed. Additionally, trichome structure and interaction with light was recorded using extended depth-of-field photomicrography, and reflectance quantified using a novel photographic technique. Trichomes of mesomorphic Type IV life forms (T. cryptantha, T. cyanea) and of the intermediate life …