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Articles 481 - 510 of 703

Full-Text Articles in Ecology and Evolutionary Biology

Aspen Status Report And Recommendation For The Book Cliffs, Paul C. Rogers, Cody M. Mittanck, Ronald J. Ryel Jan 2013

Aspen Status Report And Recommendation For The Book Cliffs, Paul C. Rogers, Cody M. Mittanck, Ronald J. Ryel

Aspen Bibliography

Regionally quaking aspen (Populus tremuloides Michx.) forests are experiencing numerous impediments to resilience. In the West, recent drought, fire suppression, insects, diseases, climate trends, inappropriate management, and ungulate herbivory are impacting these high biodiversity forests. We conducted a landscape assessment of aspen communities in the Book Cliffs region, Vernal Field Office of the Bureau of Land Management, for the purposes of determining landscape-level status of aspen and making recommendations for future management of these forests. The study area consists of 268 distinct aspen polygons totaling approximately 70 ha (174 acres) of aspen forest surrounded by much larger tracts of …


Book Cliffs Roadless Area Aspen Study 2013 : Grand & Uintah Counties, Utah, Cody M. Mittanck Jan 2013

Book Cliffs Roadless Area Aspen Study 2013 : Grand & Uintah Counties, Utah, Cody M. Mittanck

Aspen Bibliography

No abstract provided.


Heifer Calving Date Positively Influences Calf Weaning Weights Through Six Parturitions, R. A. Cushman, L. H. Kill, Richard N. Funston, E. M. Mousel, G. A. Perry Jan 2013

Heifer Calving Date Positively Influences Calf Weaning Weights Through Six Parturitions, R. A. Cushman, L. H. Kill, Richard N. Funston, E. M. Mousel, G. A. Perry

West Central Research and Extension Center, North Platte

Longevity and lifetime productivity are important factors influencing profitability for the cowcalf producer. Heifers that conceive earlier in the breeding season will calve earlier in the calving season and have a longer interval to rebreeding. Calves born earlier in the calving season will also be older and heavier at weaning. Longevity data were collected on 2,195 heifers from producers in South Dakota Integrated Resource Management groups. Longevity and weaning weight data were collected on 16,549 individual heifers at the U.S. Meat Animal Research Center (USMARC). Data were limited to heifers that conceived during their first breeding season. Heifers were grouped …


Selective Utilization Of Microhabitats By Web-Building Spiders, Kelton D. Welch Jan 2013

Selective Utilization Of Microhabitats By Web-Building Spiders, Kelton D. Welch

Theses and Dissertations--Entomology

Natural enemies are members of complex ecological communities, and their ability to contribute to the biological control of pest organisms is strongly influenced by a convoluted network of ecological interactions with many other organisms within these communities. Researchers must develop an understanding of the mechanisms that shape trophic webs to predict and promote top-down effects of predators. The behavior of predators can have a strong influence on their potential as biological control agents.

Web-building spiders are a useful example organism for the study of natural enemy behavior because of the experimentally tractable nature of their foraging behavior. Specifically, patterns in …


Refining Thresholds In Coupled Fire–Vegetation Models To Improve Management Of Encroaching Woody Plants In Grasslands, Dirac L. Twidwell Jr, Samuel D. Fuhlendorf, Charles A. Taylor Jr, William E. Rogers Jan 2013

Refining Thresholds In Coupled Fire–Vegetation Models To Improve Management Of Encroaching Woody Plants In Grasslands, Dirac L. Twidwell Jr, Samuel D. Fuhlendorf, Charles A. Taylor Jr, William E. Rogers

Department of Agronomy and Horticulture: Faculty Publications

1. Restoration priorities are typically established without quantitative information on how to overcome the thresholds that preclude successful restoration of desirable ecosystem properties and services. We seek to demonstrate that quantifying ecological thresholds and incorporating them into management-oriented frameworks provide a more comprehensive perspective on how the threshold concept can be applied to achieve restoration goals.

2. As an example, restoration actions have been largely unsuccessful when based on prevailing ecological knowledge of fire-based thresholds in nonresprouting Juniperus woodland. We build on previous threshold-based research and link well-established models from applied fire physics with a widely applied ecological positive feedback …


Ecophysiological Responses Of Tall Fescue Genotypes To Endophyte Infection And Climate Change, Marie Bourguignon Jan 2013

Ecophysiological Responses Of Tall Fescue Genotypes To Endophyte Infection And Climate Change, Marie Bourguignon

Theses and Dissertations--Plant and Soil Sciences

Tall fescue is a widely used forage grass in the eastern USA and can form a symbiosis with a fungal endophyte, which can be beneficial for the plant but can cause livestock health issues. Little is known regarding the symbiotic response to predicted climate change. To address this knowledge gap, I analyzed tall fescue variety trial data collected throughout the U.S., exploring relationships between climate variables and yield for two different fescue cultivars that were either endophyte-free or infected. This study showed no endophyte or cultivar effect on fescue yield, but identified temperature, precipitation and location as significant predictors of …


The Influence Of Different Cover Types On American Robin Nest Success In Organic Agroecosystems, John E. Quinn, Amy Oden, James R. Brandle Jan 2013

The Influence Of Different Cover Types On American Robin Nest Success In Organic Agroecosystems, John E. Quinn, Amy Oden, James R. Brandle

Biology Publications

There are many opportunities for biodiversity conservation in organic farm systems. Successful and sustainable conservation efforts in organic systems, however, need to measure appropriate outcomes. In particular, data are needed on the breeding success of associated wildlife species. We measured nesting success of the American Robin (Turdus migratorius) in woodlands embedded within eight organic farms in eastern Nebraska. We modeled daily nest survival rate to identify land use and land cover patterns that optimize conservation of birds in organic farm systems. The percentage of a crop in the fields adjacent to linear woodlands best predicted daily survival rate. …


Barrow Island Ute Guide - Non-Indigenous Invertebrates, Frogs, Reptiles & Weeds, Mike Grimm, Kristofer Collett, Jessica Harrison, Peter Davis, Marc Widmer, Andras Szito, Rob Emery, Peter Mangano, John Botha, David Robinson, Brad Maryan Jan 2013

Barrow Island Ute Guide - Non-Indigenous Invertebrates, Frogs, Reptiles & Weeds, Mike Grimm, Kristofer Collett, Jessica Harrison, Peter Davis, Marc Widmer, Andras Szito, Rob Emery, Peter Mangano, John Botha, David Robinson, Brad Maryan

Biosecurity published reports

Barrow Island, the second largest island in Western Australia, is a Class A Nature Reserve and home to a variety of rare and endangered fauna and flora, some of which occur nowhere else. To protect fauna and flora it is essential workers and visitors to the island are aware of the risks that a non-indigenous species (NIS) poses to the ecological balance of Barrow Island.

Workers and visitors to Barrow Island need to be aware and keep their eyes open for any unusual fauna and flora that might be in accommodation units, recreation areas or the work place. Reports from …


The Effect Of Temperature On Seed Quality And Quantity In Crosses Between European (Populus Tremula) And Hybrid Aspens (P. Tremula X P. Tremuloides), L. Koviuranta, T. Latva-Karjanmaa, P. Pulkkinen Dec 2012

The Effect Of Temperature On Seed Quality And Quantity In Crosses Between European (Populus Tremula) And Hybrid Aspens (P. Tremula X P. Tremuloides), L. Koviuranta, T. Latva-Karjanmaa, P. Pulkkinen

Aspen Bibliography

Hybrid aspen (Populus tremula L. Populus tremuloides Michx.) plantations are expanding in Fennoscandia and the Baltic countries; however, the possible effects of plantations on the native European aspen (P. tremula) and the level of gene flow between European and hybrid aspen have not been investigated. We studied seed quantity and quality in intraspecific and interspecific crosses of the European and hybrid aspens over a two year period. In order to study whether elevated temperatures due to climate change would benefit the species differently, we performed the crosses in different temperatures. In both years, interspecific crosses produced more seeds with higher …


Effects Of Slash Pile Burning After Restoring Conifer- Encroached Aspen, Christa M. Dagley, John-Pascal Berrill, Stephanie Coppeto, Kyle Jacobson Dec 2012

Effects Of Slash Pile Burning After Restoring Conifer- Encroached Aspen, Christa M. Dagley, John-Pascal Berrill, Stephanie Coppeto, Kyle Jacobson

Aspen Bibliography

Removal of conifers encroaching aspen stands has been advocated and is being practiced in the Lake Tahoe Basin (EIP Project #10080: Aspen Community Restoration Projects). In remote and roadless areas, thinning of conifers is generating large volumes of wood and pile burning is currently being implemented to handle this biomass on site. However, the effects of pile burning on aspen are unknown, and there is an urgent need for guidelines to support design of thinning treatment prescriptions; specifically burn pile size and safe distances from live aspen trees of any size to prevent injury.


Nature's Perfect Food, Geoffrey D. Reynolds Aug 2012

Nature's Perfect Food, Geoffrey D. Reynolds

Faculty Publications

Nature's Perfect Food is an article that describes the history of local beekeeper Jack Hartman and the benefit of local honey bees to agriculture and honey consumers.


Facilitation Drives Mortality Patterns Along Succession Gradients Of Aspen-Conifer Forests, W. John Calder, Samuel B. St. Clair Jun 2012

Facilitation Drives Mortality Patterns Along Succession Gradients Of Aspen-Conifer Forests, W. John Calder, Samuel B. St. Clair

Aspen Bibliography

While it is well established that facilitation and competition are important structuring forces in plant communities, a clear understanding of the interactions between them and how they change through the life stages of plants and affect long-term plant community development is lacking. We have observed that conifer seedlings are rarely found growing in meadows but readily establish under adjacent aspen stands, particularly at the base of aspen trees, creating the potential for antagonistic interactions in later life stages. To examine these relationships and their potential consequences on forest community development, we characterized patterns of establishment, regeneration, and overstory mortality of …


Seed Reduction In Prairie Cordgrass, Spartina Pectinata Link., By The Floret-Feeding Caterpillar Aethes Spartinana (Barnes And Mcdunnough), Jarrad R. Prasifka, D. K. Lee, Jeffrey Bradshaw, Allen S. Parrish, Michael E. Gray Jan 2012

Seed Reduction In Prairie Cordgrass, Spartina Pectinata Link., By The Floret-Feeding Caterpillar Aethes Spartinana (Barnes And Mcdunnough), Jarrad R. Prasifka, D. K. Lee, Jeffrey Bradshaw, Allen S. Parrish, Michael E. Gray

Panhandle Research and Extension Center

Insect damage to prairie cordgrass, Spartina pectinata Link., is conspicuously high in Illinois, where attempts to collect native seed show the majority of spikelets damaged with small holes. Dissection of spikes during summer reveals minute caterpillars boring though glumes and feeding on florets inside. In 2009–2010, panicles of prairie cordgrass from across its native range were used to estimate the percentage of insect-related damage and losses to seed production. Collections of caterpillars from panicles and stems were used to identify one floret-feeding species, estimate its distribution in the central USA, and assess its feeding patterns within spikes. Insect feeding damaged …


Widespread Triploidy In Western North American Aspen (Populus Tremuloides), Karen E. Mock, Colin M. Callahan, M. Nurul Islam-Faridi, John D. Shaw, Hardeep S. Rai, Stewart C. Sanderson, Carol A. Rowe, Ronald J. Ryel, Michael D. Madritch, Richard S. Gardner, Paul G. Wolf Jan 2012

Widespread Triploidy In Western North American Aspen (Populus Tremuloides), Karen E. Mock, Colin M. Callahan, M. Nurul Islam-Faridi, John D. Shaw, Hardeep S. Rai, Stewart C. Sanderson, Carol A. Rowe, Ronald J. Ryel, Michael D. Madritch, Richard S. Gardner, Paul G. Wolf

Aspen Bibliography

No abstract provided.


Pando Clone (World's Largest Living Organism?) History And Evaluation : Case Study For Revalidation, Allen V. Henningson Jan 2012

Pando Clone (World's Largest Living Organism?) History And Evaluation : Case Study For Revalidation, Allen V. Henningson

Aspen Bibliography

No abstract provided.


Decision Memo: Pando Aspen Clone Restoration Project, Kurt Robins Jan 2012

Decision Memo: Pando Aspen Clone Restoration Project, Kurt Robins

Aspen Bibliography

The Pando Clone is located in Township 26 South, Range 1 East, Sections 24 and 25 about 1 mile southwest of the Lakeside Resort on State Highway 25 and about 1 mile due east of Mallard Bay at the southwest corner of Fish Lake (see map). The Pando Clone is the largest aspen clone in the world and the largest (most massive) single living organism in existence that has been discovered to date (Grant, 1993; DeWoody et al, 2008). It encompasses approximately 106 acres and is estimated to weigh in excess of 13 million pounds (Grant, 1993). This clone is …


Fine Roots Of Aspen Clones In High Salt And Petroleum Hydrocarbon Pollution, Kim Yrjälä, Ivika Ostonen, Shinjini Mukherjee, Timo Sipila, Lu-Min Vaario, Pertti Pulkkinen Dec 2011

Fine Roots Of Aspen Clones In High Salt And Petroleum Hydrocarbon Pollution, Kim Yrjälä, Ivika Ostonen, Shinjini Mukherjee, Timo Sipila, Lu-Min Vaario, Pertti Pulkkinen

Aspen Bibliography

The quality of polluted soil can much be improved and the environmental risks reduced by use of phytoremediation. Harmful hydrocarbon compounds can be degraded through the activity of plant and its associated microbes. We previously showed that PAHs increase aromatic ring-cleavage gene diversity in rhizosphere of birch (Sipilä et al. 2008, Yrjälä et al. 2010a) and the rhizosphere of aspen harbors Burkholderia bacteria able to degrade aromatics (Yrjälä et al. 2010b). The results are promising for successful remediation of polluted soils with woody plants. The aim of our studies is to elucidate the response of the plant and the associated …


Review Of Grass: In Search Of Human Habitat. By Joe C. Truett. Foreword By Harry W. Greene., Mary Ann Vinton Oct 2011

Review Of Grass: In Search Of Human Habitat. By Joe C. Truett. Foreword By Harry W. Greene., Mary Ann Vinton

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

Much of the book is devoted to discussing the heavy human dependence on grasslands and whether this relationship can be maintained in company with grassland conservation. Can humans continue to use grasslands for food, fiber, and newer uses like biofuels and carbon banking while still sustaining the ecosystem? Many of us in academic ecology struggle with resolving perceived conflicts between conservation and human grassland use. In many cases, a "win-win" scenario exists in which, for example, the proper use of livestock grazing is perfectly compatible with a healthy grassland ecosystem. In other cases, such as conserving prairie dog populations, tensions …


Aronia Mitschurinii: Solving A Horticultural Enigma, Peter J. Leonard Aug 2011

Aronia Mitschurinii: Solving A Horticultural Enigma, Peter J. Leonard

Master's Theses

Aronia (Medik.), commonly known as chokeberry, is a taxonomically misunderstood genus currently experiencing a renaissance in North America as both an ornamental and fruit crop. Three species of chokeberry are commonly accepted as native in North America: A. arbutifolia (L.) Pers. red chokeberry; A. melanocarpa (Michx.) Elliot, black chokeberry; and A. prunifolia (Marshall) Rehder, or purple chokeberry. In Europe a fourth species of human origin is recognized as Aronia mitschurinii (A.K.Skvortsov & Maitul.), or cultivated, black-fruited Aronia. It is widely speculated that this genotype originated in the early 20th century with Russian pomologist Ivan Michurin, as the product …


Herbicide-Resistant Risk Assessment: Response Of Common Nebraska Weeds To Dicamba Dose, Roberto J. Crespo Jul 2011

Herbicide-Resistant Risk Assessment: Response Of Common Nebraska Weeds To Dicamba Dose, Roberto J. Crespo

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

Dicamba-resistant soybeans are being developed to provide an additional herbicide mechanism of action that can be used in soybean, and to provide a tool to help manage or mitigate the evolution of other herbicide-resistant weed populations. The objectives of this thesis were to assess the risk of common Nebraska weeds developing resistance to dicamba, quantify baseline dose-response to dicamba of high-risk weed species, and survey the variability in dicamba dose-response among populations of those species. Twenty-five weed scientists were asked to estimate the risk likelihood of ten weed species evolving resistance to dicamba following the commercialization of dicamba-resistant soybean. Palmer …


Preference Of White-Tailed Deer For Corn Hybrids And Agricultural Husbandry Practices During The Growing Season, Joshua A. Delger, Kevin L. Monteith, Lowell E. Schmitz, Jonathan A. Jenks Apr 2011

Preference Of White-Tailed Deer For Corn Hybrids And Agricultural Husbandry Practices During The Growing Season, Joshua A. Delger, Kevin L. Monteith, Lowell E. Schmitz, Jonathan A. Jenks

Natural Resource Management Faculty Publications

Damage to field corn (Zea mays) by white-tailed deer (Odocoileus virginianus) can be substantial, resulting in millions of dollars lost annually. Numerous methods exist to minimize deer depredation, but all have met with varying degrees of success. Currently, little information is available on preference of white-tailed deer for corn hybrids during the growing season and how that preference might affect depredation patterns. We used adult female white-tailed deer in captivity to study the effect of herbicide treatments on deer-use (treatment versus no treatment) of corn in 2005 and to document preference among specific corn hybrids in …


Leaf Number Indicates Salt Tolerance Of Young Seedling Families Of European Aspen (Populus Tremula L.) Growing In Different Soils, Lu-Min Vaario, Kim Yrjälä, Matti Rousi, Timo Sipila, Pertti Pulkkinen Mar 2011

Leaf Number Indicates Salt Tolerance Of Young Seedling Families Of European Aspen (Populus Tremula L.) Growing In Different Soils, Lu-Min Vaario, Kim Yrjälä, Matti Rousi, Timo Sipila, Pertti Pulkkinen

Aspen Bibliography

Soil salinity limits plant productivity and quality. We evaluated the response of 12 aspen (Populus tremula) families to salt stress in two different soils irrigated for 4-weeks with 0, 80 or 160 mM saline solution. Easily measurable characteristics such as shoot height, leaf number, dry mass as well as the distribution of sodium (Na+) ions were measured in 5-month-old aspen seedlings raised in controlled greenhouse conditions on two different soils. Growth among families varied significantly, and the interaction between family and soil type was significant. From 2–5 months, leaf number correlated with that of the first month and salin-ity tolerance. …


Multicentury Fire And Forest Histories At 19 Sites In Utah And Eastern Nevada, Emily K. Heyerdahl, Peter M. Brown, Stanley G. Kitchen, Marc H. Weber Jan 2011

Multicentury Fire And Forest Histories At 19 Sites In Utah And Eastern Nevada, Emily K. Heyerdahl, Peter M. Brown, Stanley G. Kitchen, Marc H. Weber

Aspen Bibliography

Our objective is to provide site-specific fire and forest histories from Utah and eastern Nevada that can be used for land management or additional research. We systematically sampled fire scars and tree-recruitment dates across broad gradients in elevation and forest type at 13 sites in Utah and 1 in eastern Nevada to characterize spatial and temporal variation in historical fire regimes as well as forest structure and composition. We collected similar data non-systematically at five additional sites in Utah. These 19 sites include a broad range of forest types (from pinyon-juniper woodlands to spruce-fir forests) and fire regime types. In …


Oregon Aspen Project, Forest Restoration Partnership Dec 2010

Oregon Aspen Project, Forest Restoration Partnership

Aspen Bibliography

The Oregon Aspen Project was initiated in response to the decline of aspen groves in Oregon and throughout the Western United States, and the lack of information to guide managers interested in stewardship to enhance this resource. There were three central goals and accompanying objectives for this project which are listed below. The project accomplishments are provided below each bulleted objective


Damage Agents And Condition Of Mature Aspen Stands In Montana And Northern Idaho, Brytten E. Steed, Holly S.J. Kearns Apr 2010

Damage Agents And Condition Of Mature Aspen Stands In Montana And Northern Idaho, Brytten E. Steed, Holly S.J. Kearns

Aspen Bibliography

No abstract provided.


An Inventory And Condition Survey Of The Western Australian Part Of The Nullarbor Region, Peter-Jon A. Waddell, A K. Gardner, P Hennig Jan 2010

An Inventory And Condition Survey Of The Western Australian Part Of The Nullarbor Region, Peter-Jon A. Waddell, A K. Gardner, P Hennig

Technical Bulletins

The inventory and condition survey of the Western Australian part of the Nullarbor region, undertaken by the Department of Agriculture and Food, Western Australia (DAFWA) between 2005 and 2007, describes and maps the natural resources of the region. This survey report provides a baseline record of the existence and condition of the area's natural resources, to assist with the planning and implementation of land management practices. The report identified and described the condition of soils, landforms, vegetation, habitat, ecosystems, and declared plants and animals. It also assessed the impact of pastoralism and made land management recommendations. The Nullarbor region has …


Pollen Interception By Linyphiid Spiders In A Corn Agroecosystem: Implications For Dietary Diversification And Risk-Assessment, Julie A. Peterson, Susan Romero, James D. Harwood Jan 2010

Pollen Interception By Linyphiid Spiders In A Corn Agroecosystem: Implications For Dietary Diversification And Risk-Assessment, Julie A. Peterson, Susan Romero, James D. Harwood

West Central Research and Extension Center, North Platte

Dietary diversification, including consumption of plant tissues such as pollen, can enhance the fecundity of generalist predators, resulting in improved control of pest prey. Supplemental pollen feeding has been observed in many natural enemies, including sheet-web spiders (Araneae: Linyphiidae), which represent a major component of food webs in agroecosystems. Their horizontal, ground-based webs have the potential to intercept pollen grains during anthesis of crop plants, providing the opportunity for consumption of pollen to occur. In laboratory feeding trials, Frontinella communis and Tennesseellum formicum (Araneae: Linyphiidae) readily fed on pollen grains dusted on their webs, with 82 and 92% of spiders …


Aspen In Scotland: Biodiversity And Management, John Parrott, Neil Mackenzie Oct 2009

Aspen In Scotland: Biodiversity And Management, John Parrott, Neil Mackenzie

Aspen Bibliography

No abstract provided.


Quantification Of Bt-Endotoxin Exposure Pathways In Carabid Food Webs Across Multiple Transgenic Events, Julie A. Peterson, John J. Obrycki, James D. Harwood Jul 2009

Quantification Of Bt-Endotoxin Exposure Pathways In Carabid Food Webs Across Multiple Transgenic Events, Julie A. Peterson, John J. Obrycki, James D. Harwood

West Central Research and Extension Center, North Platte

Despite the reported specificity of Bacillus thuringiensis proteins against target pests, a number of studies have indicated that the uptake of Bt-endotoxins from bioengineered crops could have negative effects on natural enemies. It is therefore essential to quantify exposure pathways in non-target arthropod food webs across multiple transgenic events. Adult ground beetles (Coleoptera: Carabidae) were collected from transgenic corn fields expressing lepidopteran-specific Cry1Ab, coleopteran-specific Cry3Bb1, and both Cry1Ab and Cry3Bb1 (stacked event), as well as a non-transgenic isoline. Carabid gut-contents were screened for Cry1Ab Bt-endotoxin using enzyme-linked immunosorbent assay. Significant numbers of carabids tested positive for Cry1Ab from the lepidopteran-specific …


Barrow Island Ute Guide - Non-Indigenous Insects, Spiders And Snails, Mike Grimm, Kristofer Collett, Peter Davis, Marc Widmer, Andras Szito, Rob Emery, Peter Mangano Jun 2009

Barrow Island Ute Guide - Non-Indigenous Insects, Spiders And Snails, Mike Grimm, Kristofer Collett, Peter Davis, Marc Widmer, Andras Szito, Rob Emery, Peter Mangano

Biosecurity published reports

Barrow Island, the second largest island in Western Australia, is a Class A Nature Reserve and home to a variety of rare and endangered fauna and flora, some of which occur nowhere else. The island lies about 70 km off the north-west coast of Western Australia and 150 km west of Karratha.

Oil discoveries in the 1960s and the development of massive Northwest Shelf gas reserves since the 1990s made Barrow Island an important site for these industries. Strict environmental and quarantine conditions are placed on industry seeking permits to drill oil wells and construct gas processing plants. Oil production …