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Use Of Passive Integrated Transponders In Hatchling Texas Horned Lizards, Scott E. Henke Jan 2008

Use Of Passive Integrated Transponders In Hatchling Texas Horned Lizards, Scott E. Henke

The Prairie Naturalist

The Texas horned lizard (Phrynosoma cornutum) is a Texas state-threatened species and acquisition of data related to the species' ecology is essential. To accomplish this task individual animals need to be marked. Many marking techniques are available for lizards, however the majority of techniques have been tested on adults only. Studies involving hatchling and juvenile horned lizards are scarce due to problems associated with marking and relocating individuals in these age classes. I demonstrated that injection of passive integrated transponders (PIT's) can safely be used as a marking method in young Texas horned lizards. Thirty-two captive bred hatchling lizards were …

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Engineer Cantonment, Missouri Territory, 1819-1820: America's First Biodiversity Ineventory, Hugh H. Genoways, Brett C. Ratcliffe Jan 2008

Engineer Cantonment, Missouri Territory, 1819-1820: America's First Biodiversity Ineventory, Hugh H. Genoways, Brett C. Ratcliffe

Great Plains Research: A Journal of Natural and Social Sciences (through 2013)

It is our thesis that members of the Stephen Long Expedition of 1819-20 completed the first biodiversity inventory undertaken in the United States at their winter quarters, Engineer Cantonment, Missouri Territory, in the modern state of Nebraska. This accomplishment has been overlooked both by biologists and historians, but it should rank among the most significant accomplishments of the expedition. The results of this inventory allow us to evaluate the environmental, faunal, and floral changes along the Missouri River in the intervening nearly 190 years. The historical records form a visual image of a dynamic riverine system in which a highly …

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Effects Of Agricultural Conservation Practices On Fish And Wildlife, Stuart R. Gagnon, Joseph R. Makuch, Cassandra Y. Harper Jan 2008

Effects Of Agricultural Conservation Practices On Fish And Wildlife, Stuart R. Gagnon, Joseph R. Makuch, Cassandra Y. Harper

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

This bibliography, in two volumes, is part of a multi-volume set developed by the Water Quality Information Center at the National Agricultural Library in support of the U.S. Department of Agriculture’s Conservation Effects Assessment Project (CEAP). The bibliography is a guide to recent scientific literature covering effects of agricultural conservation practices on fish and wildlife. The citations listed here provide information on how conservation programs and practices designed to improve fish and wildlife habitat, as well as those intended for other purposes, e.g., water quality improvement, affect various aquatic and terrestrial fauna.

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Corn Rootworm Areawide Pest Management In The Midwestern Usa, Laurence D. Chandler, James R. Coppedge, C. Richard Edwards, Jon J. Tollefson, Gerald R. Wilde, Robert M. Faust Jan 2008

Corn Rootworm Areawide Pest Management In The Midwestern Usa, Laurence D. Chandler, James R. Coppedge, C. Richard Edwards, Jon J. Tollefson, Gerald R. Wilde, Robert M. Faust

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

For many maize (Zea mays) producers across the Midwestern USA, as well as in parts of the northern and southern plains, the corn rootworm complex (Diabrotica spp.; Coleoptera: Chrysomelidae) has represented one of the greatest challenges to efficient, quality maize-grain production over the past 50-60 years. Three species of corn rootworm are particularly troublesome: the western corn rootworm, Diabrotica virgifera virgifera, the northern corn rootworm, D. barberi and the Mexican corn rootworm, D. virgifera zeae; all have consistently been important economic pests of maize (Metcalf, 1986b). Prior to the introduction of transgenic maize varieties designed …

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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 …

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A Dgge-Cloning Method To Characterize Arbuscular Mycorrhizal Community Structure In Soil, Zhanbei Liang, Rhae A. Drijber, Donald J. Lee, Ismail M. Dwiekat, Steven D. Harris, David A. Wedin Jan 2008

A Dgge-Cloning Method To Characterize Arbuscular Mycorrhizal Community Structure In Soil, Zhanbei Liang, Rhae A. Drijber, Donald J. Lee, Ismail M. Dwiekat, Steven D. Harris, David A. Wedin

Department of Plant Pathology: Faculty Publications

Although arbuscular mycorrhizal fungi (AMF) are crucial for ecosystem functioning, characterizing AMF community structure in soil is challenging. In this study, nested polymerase chain reaction (PCR) and denaturing gradient gel electrophoresis (DGGE) were combined with cloning of fungal 18S ribosomal gene fragments for the rapid comparison of AMF community structure in soil. Reference AMF isolates, representing four major genera of AMF, were used to develop the method. Sequential amplification of 18S rDNA fragments by nested PCR using primer pairs AM1-NS31 and Glo1-NS31GC followed by DGGE analysis yielded a high-resolution band profile. In parallel, 18S rDNA fragment clone libraries were constructed …

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Geographic Patterns Of At-Risk Species, Curtis H. Flather, Michael S. Knowles, Jason Mcnees Jan 2008

Geographic Patterns Of At-Risk Species, Curtis H. Flather, Michael S. Knowles, Jason Mcnees

United States Department of Agriculture, Forest Service / University of Nebraska-Lincoln: Faculty Publications

This technical document supports the Forest Service’s requirement to assess the status of renewable natural resources as mandated by the Forest and Rangeland Renewable Resources Planning Act of 1974. It updates past reports on the trends and geographic patterns of species formally listed as threatened or endangered under the Endangered Species Act of 1973. We compare the geographic occupancy of threatened and endangered species at the county-level against the geographic occupancy of a broader set of species thought to be at risk of extinction. This is done to determine if new areas where species rarity may be concentrated emerge. Here …

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A Landscape Perspective In Managing Vegetation For Beneficial Plant-Pestnatural Enemy Interactions: A Foundation For Areawide Pest Management, Michael J. Brewer, Takuji Noma, Norman C. Elliott Jan 2008

A Landscape Perspective In Managing Vegetation For Beneficial Plant-Pestnatural Enemy Interactions: A Foundation For Areawide Pest Management, Michael J. Brewer, Takuji Noma, Norman C. Elliott

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

In the USA, Europe and increasingly in other regions, cropping systems designed for high production output are significant features of the landscape. Deployment of mechanized and high-input cropping systems over the last 50 years has resulted in substantial transformation and fragmentation of major grassland, shrubland and woodland systems throughout the world. These cropping systems are typically less diverse in species composition, structure and ecological functioning than those found in the original plant community (Altieri, 2004). Decreases in plant diversity of agroecosystems (i.e. the crops themselves and surrounding remnants of the original plant system) have negatively affected ecosystem functions (Freemark, 2005). …

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Chapter 15. Proven Practices And Innovative Technologies For On-Farm Crop Nitrogen Management, N. R. Kitchen, K. W. T. Goulding, J.F. Shanahan Jan 2008

Chapter 15. Proven Practices And Innovative Technologies For On-Farm Crop Nitrogen Management, N. R. Kitchen, K. W. T. Goulding, J.F. Shanahan

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Nitrogen (N) from soil, fertilizer, and manure sources is generally inefficiently used (30-60%) in most crop production systems. As a consequence, unused inorganic N can move off crop fields and contaminate surface and groundwater resources. Local and national governments have responded with guidelines, standards, regulations, and in some cases fines when off-field losses of N have not been reduced. Along with these environmental pressures, soaring energy costs have resulted in commensurate increased costs for N fertilizers. These factors are real for crop producers and are compelling them to scrutinize their crop N management more closely than in previous decades. Numerous …

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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. …

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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 …

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Phenotypic Plasticity Of Reproduction In Schizachyrium Scoparium (Poaceae) Populations In Relation To Ecological History, Elizabeth M. Obee, James A. Quinn Dec 2007

Phenotypic Plasticity Of Reproduction In Schizachyrium Scoparium (Poaceae) Populations In Relation To Ecological History, Elizabeth M. Obee, James A. Quinn

Aliso: A Journal of Systematic and Floristic Botany

Genetic differentiation in reproduction in the wide-ranging Schizachyrium scoparium (Poaceae) has been demonstrated in uniform gardens. However, the fine-tuning of flowering phenology and biomass allocation in relation to spatial and temporal fluctuations in the local environment is best accomplished by plastic responses to local variability. An earlier central New Jersey study suggested that S. scoparium populations in old fields of 2 to 40 years differed in plasticity. To test this apparent effect of ecological history on the development of different levels of plasticity, genotypes were collected from high- and low-fertility sites in New Jersey (forest biome) and in Oklahoma (grassland …

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Homestead National Monument Of America Bur Oak Forest Restoration Plan: Reference Condition And Management Considerations, Steven B. Rolfsmeier Jan 2007

Homestead National Monument Of America Bur Oak Forest Restoration Plan: Reference Condition And Management Considerations, Steven B. Rolfsmeier

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

The Vegetation Management Action Plan for Homestead National Monument of America includes a statement of the desired future condition that states: "The monument's natural resources are managed in such a way as to maintain a heterogeneous landscape composed of a mosaic of high quality remnant and restored tallgrass prairie, lowland bur oak forest and associated ecotones, as well as prairie streams and their hydrologic processes; that reflects the value of the site as a homestead, represents as accurately as possible the environment encountered by early settlers, and preserves native biodiversity" (Bolli 2006). The lowland bur oak forest along Cub Creek …

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The Function Of Stilt Roots In The Growth Strategy Of Socratea Exorrhiza (Arecaceae) At Two Neotropical Sites, Gregory R. Goldsmith, Rakan A. Zahawi Jan 2007

The Function Of Stilt Roots In The Growth Strategy Of Socratea Exorrhiza (Arecaceae) At Two Neotropical Sites, Gregory R. Goldsmith, Rakan A. Zahawi

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Arboreal palms have developed a variety of structural root modifications and systems to adapt to the harsh abiotic conditions of tropical rain forests. Stilt roots have been proposed to serve a number of functions including the facilitation of rapid vertical growth to the canopy and enhanced mechanical stability. To examine whether stilt roots provide these functions, we compared stilt root characteristics of the neotropical palm tree Socratea exorrhiza on sloped ( > 20°) and flat locations at two lowland neotropical sites. S. exorrhiza (n=80 trees) did not demonstrate differences in number of roots, vertical stilt root height, root cone circumference, root …

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Lixus Cardui, A Biological Control Agent For Scotch Thistle (Onopordum Acanthium): Safe For Australia, But Not The Usa?, Joe Balciunas Jan 2007

Lixus Cardui, A Biological Control Agent For Scotch Thistle (Onopordum Acanthium): Safe For Australia, But Not The Usa?, Joe Balciunas

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Invasive exotic plants are often weeds in more than one country. After a biological control agent for a weed has been developed for use in one country, it is reasonable to consider using the same agent against the same weed in another country. ‘Transfer Projects’ can save considerable time and money, and they have been popular around the world. Lixus cardui Olivier (Coleoptera: Curculionidae), a weevil from Europe, was first used by Australian researchers to control Scotch thistle, Onopordum acanthium L. (Asteraceae). There are few close relatives of Scotch thistle in Australia, but that is not the case in North …

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Evaluating The Performance Of Leucaena Accessions For Agroforestry In Sub-Humid Environment, Southern Tanzania, A. E. Majule Dec 2006

Evaluating The Performance Of Leucaena Accessions For Agroforestry In Sub-Humid Environment, Southern Tanzania, A. E. Majule

Tanzania Journal of Science

The performance of Leucaena accessions on acid soils in eastern coast Tanzania for agroforestry was evaluated for three years. Plant tree parameters assessed were fodder yield and plant stem height, stem girth, the number of total branches and poles production. Also, Leucaena psyllid, a common pest threatening the plants was also counted. Soil parameters assessed were pH organic carbon, total nitrogen, exchangeable calcium and magnesium. Result showed significant difference in growth between Leucaena accessions. Leucaena leucocephal cv K8 and Leucaena diversifolia were able to grow fast reaching 4.7 and 3.3 m respectively within a period of three years. Leucaena diversifolia …

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Soil Microbial Community Composition As Affected By Restoration Practices In California Grassland, Rebecca E. Drenovsky, Martin Pothoff, Kerri L. Steenwerth, Louise E. Jackson, Rainer G. Joergensen, Kate M. Scow Jul 2006

Soil Microbial Community Composition As Affected By Restoration Practices In California Grassland, Rebecca E. Drenovsky, Martin Pothoff, Kerri L. Steenwerth, Louise E. Jackson, Rainer G. Joergensen, Kate M. Scow

Biology

Agricultural practices have strong impacts on soil microbes including both the indices related to biomass and activity as well as those related to community composition. In a grassland restoration project in California, where native perennial bunchgrasses were introduced into non-native annual grassland after a period of intensive tillage, weeding, and herbicide use to reduce the annual seed bank, microbial community composition was investigated. Three treatments were compared: annual grassland, bare soil fallow, and restored perennial grassland. Soil profiles down to 80cm in depth were investigated in four separate layers (0–15, 15–30, 30–60, and 60–80cm) using both phospholipid ester-linked fatty acid …

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Further Evidence For Seed Size Variation In The Genus Zostera: Exploratory Studies With Z. Japonica And Z. Asiatica, Sandy Wyllie-Echeverria, Victoria R. Wyllie-Echeverria, Algernon C. Churchill, Paul A. Cox Jan 2006

Further Evidence For Seed Size Variation In The Genus Zostera: Exploratory Studies With Z. Japonica And Z. Asiatica, Sandy Wyllie-Echeverria, Victoria R. Wyllie-Echeverria, Algernon C. Churchill, Paul A. Cox

Aliso: A Journal of Systematic and Floristic Botany

Recent studies found seed size variation within the seagrass Zostera marina, one of nine species in the genus Zostera. The objectives of this study were to determine if variation also exists in the seeds of two other species Zostera japonica and Zostera asiatica within this genus. Results indicate that: (1) length and weight varied between two populations (one indigenous population from Akkeshi-Ko, Japan, and one exotic population from Willapa Bay, Washington, USA) of the small-bodied intertidal seagrass species Z. japonica, and (2) seed-size classes were discernable. Preliminary investigations were also initiated with a Japanese population of Z. asiatica …

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Speciation In Duckweeds (Lemnaceae): Phylogenetic And Ecological Inferences, Daniel J. Crawford, Elias Landolt, Donald H. Les, Rebecca T. Kimball Jan 2006

Speciation In Duckweeds (Lemnaceae): Phylogenetic And Ecological Inferences, Daniel J. Crawford, Elias Landolt, Donald H. Les, Rebecca T. Kimball

Aliso: A Journal of Systematic and Floristic Botany

Species of duckweeds (Letnnaceae) that were resolved as sister taxa in a phylogeny based on combined molecular and non-molecular data were compared for morphological, physiological, and ecological attributes to infer factors important in the initial divergence leading to speciation. The ability to survive extreme conditions such as desiccation and cold temperatures is the most common difference identified between species. Two morphological characters facilitating survival in extreme environments are production of special resting buds called turions and increased seed production. The prevalent geographic pattern for species pairs consists of one restricted species occurring on the periphery of a more widespread taxon; …

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Impact Of Trap Design, Windbreaks, And Weather On Captures Of European Corn Borer (Lepidoptera: Crambidae) In Pheromone-Baited Traps, Thomas W. Sappington, Brendon J. Reardon, Douglas V. Sumerford Jan 2006

Impact Of Trap Design, Windbreaks, And Weather On Captures Of European Corn Borer (Lepidoptera: Crambidae) In Pheromone-Baited Traps, Thomas W. Sappington, Brendon J. Reardon, Douglas V. Sumerford

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Pheromone-baited traps are often used in ecological studies of the European corn borer, Ostrinia nubilalis (Hübner) (Lepidoptera: Crambidae). However, differences in trap captures may be confounded by trap design, trap location relative to a windbreak, and changes in local weather. The objectives of this experiment were, first, to examine differences in O. nubilalis adult (moth) captures among the Intercept wing trap, the Intercept bucket/funnel UNI trap, and the Hartstack wire-mesh, 75-cm-diameter cone trap (large metal cone trap) as well as among three cone trap designs. Second, we examined the influence of the location of the large metal cone trap relative …

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Laboratory Evaluation Of Avian Odors For Mosquito (Diptera: Culicidae) Attraction, S. A. Allan, Ulrich R. Bernier, D. L. Kline Jan 2006

Laboratory Evaluation Of Avian Odors For Mosquito (Diptera: Culicidae) Attraction, S. A. Allan, Ulrich R. Bernier, D. L. Kline

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Attraction of Culex quinquefasciatus Say, Culex tarsalis Coquillett, Culex nigripalpus Theobald, and Aedes aegypti (L.) to avian and other host odors was investigated in a dual-port olfactometer. Although attraction to a human arm was high for Ae. aegypti (>80%) and low for all Culex spp. (<25%), all species responded similarly to a chicken (55.3-73.6%). Responses of Ae. aegypti, Cx. quinquefasciatus, and Cx. nigripalpus to feathers were low (<20%) but greater than to controls. There was no difference in attraction of Cx. tarsalis to feathers or controls. Responses to CO2 (5 ml/min) were low for all species (<15%) except Cx. tarsalis, which were moderate (24.5%). When feathers were combined with CO2, the resulting attraction was additive or lower than responses …

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Bloodroot Pollination: Bet-Hedging In Uncertain Times, W. John Hayden Feb 2005

Bloodroot Pollination: Bet-Hedging In Uncertain Times, W. John Hayden

Biology Faculty Publications

“Hurry up and wait.” The phrase that epitomizes life in the military or any other large, bureaucratic, organization, applies surprisingly well to bloodroot and similar ephemeral wildflowers. Each year these plants race to flower as early as possible to assure sufficient time for fruits to ripen and seeds to mature while sunshine is abundant at the forest floor, for all too soon the forest floor will be draped in shadows cast by the trees’ leafy canopy. Ephemerals do everything quickly: sprout, grow, flower, disperse seeds, and re-enter dormancy. But flowering in very early spring can be risky. Some days will …

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Prevalence Of Pathogenic Yersinia Enterocolitica Strains In Pigs In The United States, Saumya Bhaduri, Irene V. Wesley, Eric J. Bush Jan 2005

Prevalence Of Pathogenic Yersinia Enterocolitica Strains In Pigs In The United States, Saumya Bhaduri, Irene V. Wesley, Eric J. Bush

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Yersinia enterocolitica is considered an important food-borne pathogen impacting the pork production and processing industry in the United States. Since this bacterium is a commensal of swine, the primary goal of this study was to determine the prevalence of pathogenic Y. enterocolitica in pigs in the United Sates using feces as the sample source. A total of 2,793 fecal samples were tested for its presence in swine. Fecal samples were collected from late finisher pigs from 77 production sites in the 15 eastern and midwestern pork-producing states over a period of 27 weeks (6 September 2000 to 20 March 2001). …

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Abundance Of Plodia Interpunctella (Hubner) And Cadra Cautella (Walker) Infesting Maize Stored On South Carolina Farms: Seasonal And Non-Seasonal Variation, Richard T. Arbogast, Shahpar R. Chini Jan 2005

Abundance Of Plodia Interpunctella (Hubner) And Cadra Cautella (Walker) Infesting Maize Stored On South Carolina Farms: Seasonal And Non-Seasonal Variation, Richard T. Arbogast, Shahpar R. Chini

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Seasonal trends and short-term fluctuations in abundance of Plodia interpunctella (Hubner) and Cadra cautella (Walker) infesting maize stored on two South Carolina farms were studied during three storage seasons (September 1990–June 1993). Coils of corrugated paper placed on the grain surface were used to trap mature larvae seeking pupation sites. Temperatures in the grain (18-cm-deep) and in the bin headspace were recorded hourly, and grain moisture content was measured weekly. Weekly mean numbers of moth larvae, and adults of two natural enemies, trapped in the coils were used for tracking changes in their abundance over time. The most significant findings …

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Environmental Factors Affecting Seed Persistence Of Annual Weeds Across The U.S. Corn Belt, Adam S. Davis, John Cardina, Frank Forcella, Gregg A. Johnson, George Kegode, John L. Lindquist, Edward C. Luschei, Karen A. Renner, Christy L. Sprague, Martin M. Williams Ii Jan 2005

Environmental Factors Affecting Seed Persistence Of Annual Weeds Across The U.S. Corn Belt, Adam S. Davis, John Cardina, Frank Forcella, Gregg A. Johnson, George Kegode, John L. Lindquist, Edward C. Luschei, Karen A. Renner, Christy L. Sprague, Martin M. Williams Ii

Department of Agronomy and Horticulture: Faculty Publications

Weed seedbanks have been studied intensively at local scales, but to date, there have been no regional-scale studies of weed seedbank persistence. Empirical and modeling studies indicate that reducing weed seedbank persistence can play an important role in integrated weed management. Annual seedbank persistence of 13 summer annual weed species was studied from 2001 through 2003 at eight locations in the north central United States and one location in the northwestern United States. Effects of seed depth placement, tillage, and abiotic environmental factors on seedbank persistence were examined through regression and multivariate ordinations. All species examined showed a negative relationship …

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Cattle As Grazing Management And Seed Dispersal Tools For Increasing Native Species Diversity On Great Basin Rangelands, Marina K. Whitacre May 2004

Cattle As Grazing Management And Seed Dispersal Tools For Increasing Native Species Diversity On Great Basin Rangelands, Marina K. Whitacre

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A series of experiments evaluated: 1) the influence of seed intake and gut retention time on seed passage, recovery, and germinability; 2) fecal seeding and broadcast /trampling as techniques to incorporate seeds into a well-established Agropyron desertorum (Fisch.) Schult. stand in Skull Valley , Utah; 3) intensive grazing as a means to reduce Agropyron biomass and increase establishment and survival of seeded species; and 4) the recovery and germinability of seed extracted from dung collected from the field. Two shrubs (Artemisia tridentata Nutt. ssp. wyomingensis Beetle & Young and Atriplex confertifolia Torr. & Frem.), a grass (Elymus elymoides (Raf.) …

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Vascular Plants Of The Russian Peak Area Siskiyou County, California, James P. Smith Jr, John O. Sawyer Jr. Feb 2004

Vascular Plants Of The Russian Peak Area Siskiyou County, California, James P. Smith Jr, John O. Sawyer Jr.

Botanical Studies

No abstract provided.

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Seed Mass And Morphology In Outcrossing And Selfing Species Of Clarkia (Onagraceae): An Sem Study, Jennifer L. Knies, Veronique A. Delesalle, A. R. Cavaliere Jan 2004

Seed Mass And Morphology In Outcrossing And Selfing Species Of Clarkia (Onagraceae): An Sem Study, Jennifer L. Knies, Veronique A. Delesalle, A. R. Cavaliere

Biology Faculty Publications

Seeds from three pairs of outcrossing-selfing sister taxa from the genus Clarkia (farewell-to-spring, Onagraceae)—Clarkia unguiculata, Clarkia exilis, Clarkia xantiana ssp. xantiana and ssp. parviflora, and Clarkia concinna ssp. concinna and ssp. automixa—were studied to assess the effects of contrasting mating systems on seed mass and seed morphology. For each outcrossing-selfing comparison, the seed mass of the selfing taxon was less than that of the outcrossing taxon. Seed mass typically differed significantly among populations within a taxon. Scanning electron microscopy showed that the seeds from all these taxa share several characteristics: a bullet to shield shape, a reticulate exotesta pattern, presence …

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Morphological, Anatomical And Ecological Studies On Tulipa Armena Boiss. Var. Lycica (Baker) Marais (Liliaceae), Ati̇la Ocak, Sevi̇m Alan, Ebru Ataşlar Jan 2004

Morphological, Anatomical And Ecological Studies On Tulipa Armena Boiss. Var. Lycica (Baker) Marais (Liliaceae), Ati̇la Ocak, Sevi̇m Alan, Ebru Ataşlar

Turkish Journal of Botany

This study presents investigations into the morphological, anatomical and ecological features of Tulipa armena Boiss. var. lycica (Baker) Marais. T. armena var. lycica, an endemic species which was collected from the Eskişehir, Alpu-Bozan plantation area and from Kunduzlar Dam and its environs. The species is a new record for Eskişehir. For morphological studies a description and illustrations of T. armena var. lycica are given. The morphological differences were compared with the Flora of Turkey. For anatomical studies, cross-sections of the root, stem and leaves and surface sections of the leaves of T. armena var. lycica are investigated for the first …

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Spatial Heterogeneity Of Soil Nutrients, Nitrogen Dynamics, And Vegetation In A 3rd Order Stream Floodplain In Southwestern West Virginia, David Allen Dick Jan 2003

Spatial Heterogeneity Of Soil Nutrients, Nitrogen Dynamics, And Vegetation In A 3rd Order Stream Floodplain In Southwestern West Virginia, David Allen Dick

Theses, Dissertations and Capstones

Soil processes often exhibit spatial heterogeneity within ecosystems and this heterogeneity may influence community structure. This study was conducted to determine spatial patterns and variability of soil nutrients and plant communities within different vegetation types in a stream floodplain in southwestern West Virginia. One 5-m × 5-m site was established in each of three vegetation/drainage types: pasture (PA), old field (OF), and wetland scar (SC). Pasture and SC sites were located ~25 m apart on flat bottomland; the OF site was located on a moderate slope 6.3 m above bottomland, ~200 m from PA and SC. A 10-m × 1-m …

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