Digital Commons Network^™

Establishment Of Wildflower Islands To Enhance Roadside Health, Ecological Value, And Aesthetics Phase Ii, Jackson Ebbers, Heidi L. Hillhouse, John A. Guretsky, Thomas J. Weissling

Nebraska Department of Transportation: Research Reports

No abstract provided.

Regeneration Strategies And Forest Resilience To Changing Fire Regimes: Insights From A Goldilocks Model, Tanjona Ramiadantsoa, Zak Ratajczak, Monica G. Turner

Aspen Bibliography

Disturbances are ubiquitous in ecological systems, and species have evolved a range of strategies to resist or rebound following disturbance. Understanding how the presence and complementarity of regeneration traits will affect community responses to disturbance is increasingly urgent as disturbance regimes shift beyond their historical ranges of variability. We define "disturbance niche" as a species' fitness across a range of disturbance sizes and frequencies that can reflect the fundamental or realized niche, that is, whether the species occurs alone or with other species. We developed a model of intermediate complexity (i.e., a Goldilocks model) to infer the disturbance niche. We …

Global Distribution And Richness Of Armillaria And Related Species Inferred From Public Databases And Amplicon Sequencing Datasets, Rachel A. Koch, Joshua Herr

Department of Plant Pathology: Faculty Publications

Armillaria is a globally distributed fungal genus most notably composed of economically important plant pathogens that are found predominantly in forest and agronomic systems. The genus sensulato has more recently received attention for its role in woody plant decomposition and in mycorrhizal symbiosis with specific plants. Previous phylogenetic analyses suggest that around 50 species are recognized globally. Despite this previous work, no studies have analyzed the global species richness and distribution of the genus using data derived from fungal community sequencing datasets or barcoding initiatives. To assess the global diversity and species richness of Armillaria, we mined publicly available sequencing …

Rhizosphere Microbiome Of Arid Land Medicinal Plants And Extra Cellular Enzymes Contribute To Their Abundance, Abdul Latif Khan, Sajjad Asaf, Raeid M. M. Abed, Yen Ning Chai, Ahmed N. Al-Rawahi, Tupan Kumar Mohanta, Ahmed Al-Rawahi, Daniel P. Schachtman, Ahmed Al-Harrasi

Department of Agronomy and Horticulture: Faculty Publications

Revealing the unexplored rhizosphere microbiome of plants in arid environments can help in understanding their interactions between microbial communities and plants during harsh growth conditions. Here, we report the first investigation of rhizospheric fungal and bacterial communities of Adenium obesum, Aloe dhufarensis and Cleome austroarabica using next-generation sequencing approaches. A. obesum and A. dhufarensis grows in dry tropical and C. austroarabica in arid conditions of Arabian Peninsula. The results indicated the presence of 121 fungal and 3662 bacterial operational taxonomic units (OTUs) whilst microbial diversity was significantly high in the rhizosphere of A. obesum and A. dhufarensis and low …

The Family Rhabdoviridae: Mono- And Bipartite Negative-Sense Rna Viruses With Diverse Genome Organization And Common Evolutionary Origins, Ralf G. Dietzgen, Hideki Kondo, Michael M. Goodin, Gael Kurath, Nikos Vasilakis

Plant Pathology Faculty Publications

The family Rhabdoviridae consists of mostly enveloped, bullet-shaped or bacilliform viruses with a negative-sense, single-stranded RNA genome that infect vertebrates, invertebrates or plants. This ecological diversity is reflected by the diversity and complexity of their genomes. Five canonical structural protein genes are conserved in all rhabdoviruses, but may be overprinted, overlapped or interspersed with several novel and diverse accessory genes. This review gives an overview of the characteristics and diversity of rhabdoviruses, their taxonomic classification, replication mechanism, properties of classical rhabdoviruses such as rabies virus and rhabdoviruses with complex genomes, rhabdoviruses infecting aquatic species, and plant rhabdoviruses with both mono- …

Cover Crop Mixture Diversity And Function, Angela Florence

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

The objective of this study was to evaluate the effect of cover crop mixture diversity on cover crop function. Specifically, this study evaluated the effect of cover crop species and functional richness on aboveground biomass productivity, weed suppression, soil nutrient retention, soil microbial community characteristics, and performance stability. Twenty to forty cover crop treatments were replicated three to four times at eleven sites across southeastern Nebraska using a pool of eighteen species representing three cover crop species each from six pre-defined functional groups: cool-season grasses, cool-season legumes, cool-season brassicas, warm-season grasses, warm-season legumes, and warm-season broadleaves. Each species was planted …

How Nebraska’S Eastern Saline Wetland Native Plant Species Grow In Response To Restoration Methods: Application Of Different Salinity Level Groundwater, Ellen Dolph, Keunyea Song, Amy Burgin, Trenton E. Franz

UCARE Research Products

Nebraska’s Eastern Saline Wetlands are unique ecosystems endemic to the Salt and Rock Creek waters in Lancaster and Saunders County.

They provide an ecosystem services as well as habitat for endangered species such as the state endangered saltwort (Salicornia rubra) and federally endangered Salt Creek tiger beetle (Cicindela nevadica lincolniana).

Over 80 % of the saline wetlands are highly degraded and in recent years, the Saline Wetland Conservation Partnership has formed to conserve and restore the remaining saline wetland fragments, but there is limited information about inland saline wetland restoration. Purpose: Investigate techniques to better conserve …

Drought Responsive Gene Expression Regulatory Divergence Between Upland And Lowland Ecotypes Of A Perennial C4 Grass, John T. Lovell, Scott Schwartz, David B. Lowry, Eugene V. Shakirov, Jason E. Bonnette, Xiaoyu Weng, Mei Wang, Jenifer Johnson, Avinash Sreedasyam, Christopher Plott, Jerry Jenkins, Jeremy Schmutz, Thomas E. Juenger

Biological Sciences Faculty Research

Climatic adaptation is an example of a genotype-by-environment interaction (G×E) of fitness. Selection upon gene expression regulatory variation can contribute to adaptive phenotypic diversity; however, surprisingly few studies have examined how genome-wide patterns of gene expression G×E are manifested in response to environmental stress and other selective agents that cause climatic adaptation. Here, we characterize drought-responsive expression divergence between upland (drought-adapted) and lowland (mesic) ecotypes of the perennial C₄ grass, Panicum hallii, in natural field conditions. Overall, we find that cis-regulatory elements contributed to gene expression divergence across 47% of genes, 7.2% of which exhibit drought-responsive G×E. …

Conditional Vulnerability Of Plant Diversity To Atmospheric Nitrogen Deposition Across The United States, Samuel M. Simkin, Edith B. Allen, William D. Bowman, Christopher M. Clark, Jayne Belnap, Matthew L. Brooks, Brian S. Cade, Scott L. Collins, Linda H. Geiser, Frank S. Gilliam, Sarah E. Jovan, Linda H. Pardo, Bethany K. Schulz, Carly J. Stevens, Katharine N. Suding, Heather L. Throop, Donald M. Waller

Biological Sciences Faculty Research

Atmospheric nitrogen (N) deposition has been shown to decrease plant species richness along regional deposition gradients in Europe and in experimental manipulations. However, the general response of species richness to N deposition across different vegetation types, soil conditions, and climates remains largely unknown even though responses may be contingent on these environmental factors. We assessed the effect of N deposition on herbaceous richness for 15,136 forest, woodland, shrubland, and grassland sites across the continental United States, to address how edaphic and climatic conditions altered vulnerability to this stressor. In our dataset, with N deposition ranging from 1 to 19 kg …

16. A Comparison Of Soil Biodiversity In Restored Prairie Plots And Agricultural Fields At A Biomass Production Farm In Southeastern Minnesota, Bruno Borsari, Neal Mundahl, Malcolm Vidrine

North American Prairie Conference Proceedings

Communities of soil-dwelling organisms contribute to soil fertility and nutrient cycling, but conventional farming practices can disturb and reduce these communities. In southeastern Minnesota, some farmers are planting simplified prairie vegetation to produce biomass fuels. Our study was designed to assess the species abundance and diversity of soil invertebrates in plantings of mixed grasses only (MG) and mixed grasses with forbs (MGF) that were planted for use as a biomass fuel source on a farm in southeastern Minnesota in 2007. Abundance and diversity of soil invertebrates also were examined in soils of corn (Zea mays L.) fields grown on the …

05. Bird Communities Within A Prairie/Wetland Complex: Restoration Of Former Wastewater Treatment Ponds In Southeastern Minnesota, Neal Mundahl, Bruno Borsari

North American Prairie Conference Proceedings

Our 12-mo study examined the bird communities associated with three habitat types at differing stages of restoration within a prairie/wetland complex in southeastern Minnesota. The 25-ha site previously consisted of three municipal wastewater treatment ponds that were taken off-line in 2002. One pond was retained as a shallow wetland; the others were reconfigured and restored by planting with prairie vegetation (one pond in 2003 and the other pond in 2013) to provide habitat for both wetland and grassland birds. Timed walking surveys of birds in each habitat were made monthly from June 2014 through May 2015. We observed 48 bird …

Characterization Of Culturable Bacterial Endophytes And Their Capacity To Promote Plant Growth From Plants Grown Using Organic Or Conventional Practices, Ye Xia, Seth Debolt, Jamin Dreyer, Delia Scott, Mark A. Williams

Horticulture Faculty Publications

Plants have a diverse internal microbial biota that has been shown to have an important influence on a range of plant health attributes. Although these endophytes have been found to be widely occurring, few studies have correlated agricultural production practices with endophyte community structure and function. One agricultural system that focuses on preserving and enhancing soil microbial abundance and biodiversity is organic farming, and numerous studies have shown that organically managed system have increased microbial community characteristics. Herein, the diversity and specificity of culturable bacterial endophytes were evaluated in four vegetable crops: corn, tomato, melon, and pepper grown under organic …

Distribution And Diversity Of Ant Genera From Selected Ecoregions Across Nebraska, Jessica Jurzenski, Marc Albrecht, W. Wyatt Hoback

The Prairie Naturalist

We documented distribution and diversity of ant genera in four of the six-level III ecoregions across Nebraska. We sampled ants using bait cards, pitfall traps, and by opportunistic sampling, including direct collection and in carrion-baited pitfall traps. We identified 22 genera from five subfamilies, which were further classified into six functional groups. In common with other Great Plains states, Formica Linnaeus and Lasius Fabricius occurred most frequently in our samples, and overall ant genus-level richness was comparable to surrounding states. We compared genera similarity using Jaccard’s similarity index within and between the High Plains (western-most) and Western Corn Belt Plains …

Genetic Mapping Of Quantitative Trait Loci Associated With Bioenergy Traits, And The Assessment Of Genetic Variability In Sweet Sorghum (Sorghum Bicolor (L.). Moench), Aatshwaelwe Lekgari Lekgari

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

Sweet sorghum, a botanical variety of sorghum is a potential source of bioenergy because high sugar levels accumulate in its stalks. The objectives of this study were to explore the global diversity of sweet sorghum germplasm, and map the genomic regions that are associated with bioenergy traits. In assessing diversity, 142 sweet sorghum accessions were evaluated with three marker types (SSR, SRAP, and morphological markers) to determine the degree of relatedness among the accessions. The traits measured (anthesis date [AD], plant height [PH], biomass yield [BY], and moisture content [MC]) were all significantly different (P<0.05) among accessions. Morphological marker clustered the accessions into five groups based on PH, MC and AD. The three traits accounted for 92.5% of the variation. There were four and five groups based on SRAP and SSR data respectively classifying accessions mainly on their origin or breeding history. The observed difference between SSR and SRAP based clusters could be attributed to the difference in marker type. SSRs amplify any region of the genome whereas SRAP amplify the open reading frames and promoter regions. Comparing the three marker-type clusters, the markers complimented each other in grouping accessions and would be valuable in assisting breeders to select appropriate lines for crossing. In evaluating QTLs that are associated with bioenergy traits, 165 recombinant inbred lines (RILs) were planted at four environments in Nebraska. A genetic linkage map constructed spanned a length of 1541.3 cM, and generated 18 linkage groups that aligned to the 10 sorghum chromosomes. Fourteen QTLs (6 for brix, 3 for BY, 2 each for AD and MC, and 1 for PH) were mapped. QTLs for the traits that were significantly correlated, colocalized in two clusters on linkage group Sbi01b. Both parents contributed beneficial alleles for most of traits measured, supporting the transgressive segregation in this population. Additional work is needed on exploiting the usefulness of chromosome 1 in breeding sorghum for bioenergy.

Disturbance And Plant Succession In The Mojave And Sonoran Deserts Of The American Southwest, Scott R. Abella

Public Policy and Leadership Faculty Publications

Disturbances such as fire, land clearing, and road building remove vegetation and can have major influences on public health through effects on air quality, aesthetics, recreational opportunities, natural resource availability, and economics. Plant recovery and succession following disturbance are poorly understood in arid lands relative to more temperate regions. This study quantitatively reviewed vegetation reestablishment following a variety of disturbances in the Mojave and Sonoran Deserts of southwestern North America. A total of 47 studies met inclusion criteria for the review. The time estimated by 29 individual studies for full reestablishment of total perennial plant cover was 76 years. Although …

Global Assessment Of Nitrogen Deposition Effects On Terrestrial Plant Diversity : A Synthesis, R. Bobbink, K. Hicks, J. Galloway, T. Spranger, R. Alkemade, M. Ashmore, M. Bustamante, S. Cinderby, E. Davidson, F. Dentener, B. Emmett, J. W. Erisman, M. Fenn, Frank S. Gilliam, A. Nordin, L. Pardo, W. Devries

Biological Sciences Faculty Research

Atmospheric nitrogen (N) deposition is a recognized threat to plant diversity in temperate and northern parts of Europe and North America. This paper assesses evidence from field experiments for N deposition effects and thresholds for terrestrial plant diversity protection across a latitudinal range of main categories of ecosystems, from arctic and boreal systems to tropical forests. Current thinking on the mechanisms of N deposition effects on plant diversity, the global distribution of G200 ecoregions, and current and future (2030) estimates of atmospheric N-deposition rates are then used to identify the risks to plant diversity in all major ecosystem types now …

Species Richness And Soil Properties In Pinus Ponderosa Forests: A Structural Equation Modeling Analysis, Daniel C. Laughlin, Scott R. Abella, W. Wallace Covington, James B. Grace

Public Policy and Leadership Faculty Publications

Question: How are the effects of mineral soil properties on understory plant species richness propagated through a network of processes involving the forest overstory, soil organic matter, soil nitrogen, and understory plant abundance? Location: North-central Arizona, USA. Methods: We sampled 75 0.05-ha plots across a broad soil gradient in a Pinus ponderosa (ponderosa pine) forest ecosystem. We evaluated multivariate models of plant species richness using structural equation modeling. Results: Richness was highest at intermediate levels of understory plant cover, suggesting that both colonization success and competitive exclusion can limit richness in this system. We did not detect a reciprocal positive …

Agribusiness Sheep Updates - 2004 Part 2, Anyou Liu, Clinton Revell, Phil Nichols, Brad Nutt, Darryl Clements, Lucy Anderton, Stephen Gherardi, Chris Oldham, Paul Sanford, John Gladman, G. E. Donald, A. Edirisinghe, D. A. Henry, S. P. Gittins, R. C. G. Smith, Roy Butler, Kelly Pearce, David Masters, David Pethick, Andrew Thompson, Ken Hart, Johan Greeff, Beth Paganoni, Rachel Kirby, Matt Ryan, Kira Butler, Roger Heggarty, David Hopkins, Samantha Giles, Tom Plaisted, Mark Ferguson, Darren Gordon, John Young, Sandra Brown, Ian Mcfarland, John Archer, John Milton, Rob Davidson, Graeme Martin, David Lindsay, Johnathan England, Mandy Curnow, Karina P. Wood, Ashley K. White, B. Lloyd Davies, Paul M. Carberry, Mark Hyder, Mike Freer, Andrew Van Burgel, Kazue Tanaka, Andrew Peterson, Roger Wiese, Gonzalo Mata, Evan Burt, Amanda Miller, Anne Bennett, Felicity Flugge, Amir Abadi, Perry Dolling, Dean Thomas, Mike Ewing, David Lindsay, Emma Kopke, E. A. Dowling, E. K. Crossley, Brien (Ben) E. Norton, John Karlsson, Geoff Pollott, Diana Fedorenko, Darryl Clements, Robert Beard, Brown Besier, Una Ryan, Caroline Bath

Sheep Updates

Precision Pastures

Using Species Diversity to Improve Pasture Performance Anyou Liu and Clinton Revell, Department of Agriculture, Western Australia

New Annual Pasture Legumes for Sheep Graziers Phil Nichols, Angelo Loi, Brad Nutt and Darryl McClements Department of Agriculture Western Australia

Pastures from Space – Can Satellite Estimates of Pasture Growth Rate be used to Increase Farm Profit? Lucy Anderton, Stephen Gherardi and Chris Oldham Department of Agriculture Western Australia

Summer-active Perennial Grasses for Profitable Sheep Production Paul Sanford and John Gladman, Department of Agriculture, Western Australia

Pastures From Space – Validation Of Predictions Of Pasture Growth Rates DONALD, G.E^{.A …}

Plant Germplasm Resources, S. A. Eberhart, H. E. Bockelman

Herbarium Publications

Landraces and wild relatives of crops from centers of diversity have been rich sources of resistance to new pathogens, insect pests, and other stresses as well as for traits to improve food and fiber quality, animal feed, and industrial products. Because very few crops grown in the U.S. are native, plant introductions are vital to our agriculture. The National Plant Germplasm System (NPGS) was established to acquire, preserve, and distribute plant genetic resources from around the world so that scientists have immediate access to these source materials. The active collection is maintained and distributed by 19 national germplasm repositories. The …

Breeding Potential Of Exotic Barley Germplasm, Merja Veteläinen

Herbarium Publications

Utilization of exotic germplasm offers an approach to broaden genetic variability in breeding populations. This study was conducted in order to 1) compare germplasm of exotic origin with adapted Swedish barleys with respect to genetic differences and 2) to evaluate first cycles of pre-breeding i.e. agronomic traits in complex exotic x adapted crosses. Allozyme studies showed the following Nei's gene diversities among parents: 0.13 (adapted parents), 0.16 (landraces) and 0.25 (H. spontaneum). Cluster analysis based both on allozyme and agronomic data indicated that parental groups were genetically divergent. Earliness, straw length, number of ears per plant and thousand …