Digital Commons Network^™

Coupling Of Carbon Dioxide And Water Vapor Exchanges Of Irrigated And Rainfed Maize–Soybean Cropping Systems And Water Productivity, Andrew E. Suyker, Shashi B. Verma

School of Natural Resources: Faculty Publications

Continuous measurements of CO₂ and water vapor exchanges made in three cropping systems (irrigated continuous maize, irrigated maize–soybean rotation, and rainfed maize–soybean rotation) in eastern Nebraska, USA during 6 years are discussed. Close coupling between seasonal distributions of gross primary production (GPP) and evapotranspiration (ET) were observed in each growing season. Mean growing season totals of GPP in irrigated maize and soybean were 1738 ± 114 and 996 ± 69 g C m⁻², respectively (±standard deviation). Corresponding mean values of growing season ET totals were 545 ± 27 and 454 ± 23 mm, respectively. Irrigation affected GPP …

Growing Season Definition And Use In Wetland Delineation, Karen Malone, Hans Williams

eBooks

The definition of growing season in the 1987 U.S. Army Corps of Engineers Wetland Delineation Manual is derived from the soil biological-zero temperature concept. Lacking direct information on soil temperatures, minimum air temperature thresholds are used as indicators of the beginning and ending dates for the growing season. The 1987 Manual regional supplements allow for field observations of above-ground plant growth to estimate the growing season period. Since acceptance of the 1987 Manual, the growing season concept has been controversial. Soil biological zero does not apply to large areas of the continental United States, minimum air temperature thresholds appear inconsistent …

Shadetree Insect Pest Management, Diane Alston

Archived Gardening Publications

No abstract provided.

Relative Allelopathic Potential Of Invasive Plant Species In A Young Disturbed Woodland, Nikki Pisula, Scott J. Meiners

Faculty Research & Creative Activity

Invasive plant species are often more successful within introduced areas when compared to their natural ranges. Allelopathy has been suggested as a potential mechanism for this success because invasive plants frequently establish monocultures and may produce allelochemicals evolutionarily novel to the recipient community. However, species are typically tested in isolation making the relative strength of allelopathy difficult to assess. We conducted laboratory bioassays for 10 co-occurring non-native species to determine the relative strength of their allelopathic potential. These species represented a suite of successful invaders within a young forest and were from a variety of plant life forms: trees, lianas, …

A Catalogue Of The Ruby Van Deventer Collection In The Humboldt State University Herbarium, James P. Smith Jr, Thomas W. Nelson Jr.

Botanical Studies

No abstract provided.

Land Use And Climatic Factors Structure Regional Patterns In Soil Microbialcommunities, Rebecca E. Drenovsky, Kerri L. Steenworth, Louise E. Jackson, Kate M. Scow

Biology

Aim Although patterns are emerging for macroorganisms, we have limited under- standing of the factors determining soil microbial community composition and productivity at large spatial extents. The overall objective of this study was to discern the drivers of microbial community composition at the extent of biogeo- graphical provinces and regions. We hypothesized that factors associated with land use and climate would drive soil microbial community composition and biomass. Location Great Basin Province, Desert Province and California Floristic Province, California, USA. Methods Using phospholipid fatty acid analysis, we compared microbial com- munities across eight land-use types sampled throughout the State of …

Plant Community And Tissue Chemistry Responses To Fertilizer And Litter Nutrient Manipulations In A Temperate Grassland, Rebecca E. Drenovsky, Jean J. Pan, Brittany Widner, Deborah Ammerman

Biology

Human-mediated nutrient amendments have widespread effects on plant communities. One of the major consequences has been the loss of species diversity under increased nutrient inputs. The loss of species can be functional group dependent with certain functional groups being more prone to decline than others. We present results from the sixth year of a long-term fertilization and litter manipulation study in an old-field grassland. We measured plant tissue chemistry (C:N ratio) to understand the role of plant physiological responses in the increase or decline of functional groups under nutrient manipulations. Fertilized plots had significantly more total aboveground biomass and live …

Relative Allelopathic Potential Of Invasive Plant Species In A Young Disturbed Woodland, Nikki Pisula, Scott Meiners

Faculty Research & Creative Activity

Invasive plant species are often more successful within introduced areas when compared to their natural ranges. Allelopathy has been suggested as a potential mechanism for this success because invasive plants frequently establish monocultures and may produce allelochemicals evolutionarily novel to the recipient community. However, species are typically tested in isolation making the relative strength of allelopathy difficult to assess. We conducted laboratory bioassays for 10 co-occurring non-native species to determine the relative strength of their allelopathic potential. These species represented a suite of successful invaders within a young forest and were from a variety of plant life forms: trees, lianas, …

Allelopathic Effects Of Goldenrod Species On Turnover In Successional Communities, Nikki Pisula, Scott Meiners

Faculty Research & Creative Activity

While goldenrod species are often found to be allelopathic in laboratory settings, its importance in controlling plant community dynamics has been much more difficult to assess. We designed a study to determine whether allelopathy is related to the success of goldenrods in abandoned agricultural land. To accomplish this, we conducted laboratory bioassays for six co-occurring goldenrod species and compared these results to the cover and impacts of these species in the field. We determined the germination responses of two target species to a gradient of leaf extract concentrations to assess the allelopathic potential of these goldenrods. We also used long-term …

Spatiotemporal Dynamics Of Lianas During 50 Years Of Succession To Temperate Forest, Laura Ladwig, Scott Meiners

Faculty Research & Creative Activity

Although they are important components of forest communities, the general ecology and spatiotemporal patterns of temperate lianas during forest regeneration are largely unknown. The dependence of lianas on other plants for physical support makes them a potentially important driver of community dynamics. We examined 50 years of vegetation data from an old-field succession study to determine the dynamics and community controls on liana expansion within the Piedmont region of New Jersey, USA. Four lianas, Lonicera japonica, Parthenocissus quinquefolia, Toxicodendron radicans, and Vitis spp., occurred in enough abundance for detailed analyses. In general, liana cover peaked during mid-succession (20–30 years post-abandonment) …

Shiga Toxin Is Transported Into The Nucleoli Of Intestinal Epithelial Cells Via A Carrier-Dependent Process, Boris Baibakov, Rakhilya Murtazina, Christian Elowsky, Francis M. Giardiello, Olga Kovbasnjuk

Department of Plant Pathology: Faculty Publications

Shiga toxin (Stx) produced by the invasive Shigella dysenteriae serotype 1 (S. dysenteriae1) causes gastrointestinal and kidney complications. It has been assumed that Stx is released intracellularly after enterocyte invasion by S. dysenteriae1. However, there is little information about Stx distribution inside S. dysenteriae1-infected enterocytes. Here, we use intestinal epithelial T84 cells to characterize the trafficking of Stx delivered into the cytosol, in ways that mimic aspects of S. dysenteriae1 infection. We find that cytoplasmic Stx is transported into nucleoli. Stx nucleolar movement is carrier- and energy-dependent. Stx binding to the nucleoli of normal human …

Vascular Plants Of Adjacent Serpentine And Granite Outcrops On The Deer Isles, Maine, Usa, N Pope, T B. Harris, N Rajakaruna

Faculty Publications, Biological Sciences

We performed a comparative study of the vascular flora of a serpentine outcrop, Pine Hill, and that of a granite outcrop, Settlement Quarry, from Little Deer Isle and Deer Isle, respectively, Hancock County, Maine. We established four transects along a gradient from exposed to forested areas within each outcrop. Plants were recorded for presence and percent cover from circular plots along each transect. Soil and tissue samples were collected to examine soil-tissue elemental relations. One hundred thirty-two taxa were recorded from serpentine and 89 from granite. Fifty-seven taxa were shared by both sites. Species richness (α diversity) and diversity indices …

Occurrence Of Anisophylly And Anisoclady Within The Amaranthaceae [Abstract], Donald B. Pratt, Lynn G. Clark

Faculty Publications

No abstract provided.

Liana Host Preference And Implications For Deciduous Forest Regeneration, Laura M. Ladwig, Scott J. Meiners

Faculty Research & Creative Activity

Lianas have the potential to shape forest communities and alter forest regeneration. However, impacts of lianas on forest regeneration, particularly in temperate forests, are largely unstudied. To understand potential liana impacts on the community we need to first know the location and intensity of liana burdens on host trees. We examined liana-tree host references within a series of young regenerating deciduous forests in the Piedmont region of New Jersey, USA. Established trees ($ 5 cm dbh) and the lianas associated with each tree were surveyed in 2008. The five most abundant liana species were Celastrus orbiculatus, Lonicera japonica, Parthenocissus quinquefolia, …

Spatiotemporal Dynamics Of Lianas During 50 Years Of Succession To Temperate Forest, Laura Ladwig, Scott J. Meiners

Faculty Research & Creative Activity

Although they are important components of forest communities, the general ecology and spatiotemporal patterns of temperate lianas during forest regeneration are largely unknown. The dependence of lianas on other plants for physical support makes them a potentially important driver of community dynamics. We examined 50 years of vegetation data from an old-field succession study to determine the dynamics and community controls on liana expansion within the Piedmont region of New Jersey, USA. Four lianas, Lonicera japonica, Parthenocissus quinquefolia, Toxicodendron radicans, and Vitis spp., occurred in enough abundance for detailed analyses. In general, liana cover peaked during mid-succession (20–30 years post-abandonment) …

Allelopathic Effects Of Goldenrod Species On Turnover In Successional Communities, Nikki Pisula, Scott J. Meiners

Faculty Research & Creative Activity

While goldenrod species are often found to be allelopathic in laboratory settings, its importance in controlling plant community dynamics has been much more difficult to assess. We designed a study to determine whether allelopathy is related to the success of goldenrods in abandoned agricultural land. To accomplish this, we conducted laboratory bioassays for six co-occurring goldenrod species and compared these results to the cover and impacts of these species in the field. We determined the germination responses of two target species to a gradient of leaf extract concentrations to assess the allelopathic potential of these goldenrods. We also used long-term …

Liana Host Preference And Implications For Deciduous Forest Regeneration, Laura Ladwig, Scott Meiners

Faculty Research & Creative Activity

Lianas have the potential to shape forest communities and alter forest regeneration. However, impacts of lianas on forest regeneration, particularly in temperate forests, are largely unstudied. To understand potential liana impacts on the community we need to first know the location and intensity of liana burdens on host trees. We examined liana-tree host references within a series of young regenerating deciduous forests in the Piedmont region of New Jersey, USA. Established trees ($ 5 cm dbh) and the lianas associated with each tree were surveyed in 2008. The five most abundant liana species were Celastrus orbiculatus, Lonicera japonica, Parthenocissus quinquefolia, …

Genetic Characteristics And Environmental Parameters For Growing Turfgrass In Closed And Retractable Dome Stadiums, Bruce Bugbee, Paul Johnson

Turfgrass

Our analysis indicates that electric lighting for turfgrass growth is highly cost effective, if it is coupled with appropriate genetic and environmental changes.

Inadequate light levels for vigorous turf growth is the key challenge associated with growing turf in enclosed and retractable dome stadiums. The light levels of closed stadiums are too low to maintain vigorous plant growth that can quickly recover from the damage caused by athletic events. As a solution, retractable-dome stadiums have been built. However, even with the roof open, light levels in these stadiums are less than half of natural sunlight because of shading from the …

Summer Heat And An Epidemic Of Cytospora Canker Of Alnus, James J. Worrall, Gerard C. Adams, Sarah C. Tharp

Department of Plant Pathology: Faculty Publications

An epidemic of cytospora canker [Valsa melanodiscus, anamorph Cytospora umbrina] is associated with dieback and mortality of Alnus incana ssp. tenuifolia in the Southern Rocky Mountains and had begun by the late 1980s. Isolations showed that inoculum was often abundant on bark and bud surfaces even in winter, especially near diseased stems. The pathogen was occasionally isolated from internal tissues of dormant buds and asymptomatic wood and phloem. In infected stems, the pathogen was detected up to 5 cm beyond visible canker margins. The data suggest that the pathogen can cause latent infections, but the infection court …

Maria Sibylla Merian's Frogs, Kay Etheridge

Biology Faculty Publications

Maria Sibylla Merian (German, 1647-1717) is best known for her magnificent 1705 publication, Metamorphosis insectorum surinamensium, although she published earlier works on insect metamorphosis. Merian wrote the text and painted all of the illustrations for her books, and for the early volumes she produced most of the engravings. Contemporary scholarship has focused primarily on Merian's detailed images of lepidopteran and host plant life cycles, but Merian's Surinam album also portrays anuram metamorphosis, including the first European depiction of Pipa pipa.

Post-­Fire Alterations In Mechanical Strength Of Leaves In Heteromeles Arbutifolia, Andrew Hair, Madeline Dilascia, Nick Novella, Taylor Wurdeman

Featured Research

Wildfires in the Santa Monica mountains in Southern California burn down a decent percentage of the local vegetation. However, some plants like Heteromeles Arbutifolia, are considered to be resprouters because they return a mere two years after being burnt down. It is hypothesized that the artificially browsed resprout leaves will have a lower tensile strength than both the young and adult leaves because they use a lower amount of carbohydrates per unit-leaf-area. Data showed that although there was a slight different between the young leaves and the adult leaves of the Heteromeles, there was no statistically significant difference between the …

A Comparison Of The Tensile Strength Of Leaves In Encelia Californica In Canyon And Beach Species, Anna Chowaniec, Annie Lee, Hayley Springs

Featured Research

Our research is concerned with the further exploration of leaf biomechanics, a relatively unexamined field. The purpose of this experiment was to find a correlation between environmental stress factors and tensile strength of leaves of Encelia californica. We hypothesized the beach species would have a higher tensile strength than canyon species. After evaluating data collected from both Pepperdine’s Presidents Canyon and Malibu beach we found that while the canyon species could withstand a higher maximum load of force, there was no difference between the canyon and the beach species with leaf area taken into account. Using Young’s Modulus, we …

Turnover Of Mature Mirnas And Sirnas In Plants And Algae, Heriberto Cerutti, Fadia Ibrahim

Center for Plant Science Innovation: Faculty Publications

rnicroRNAs (miRNAs) and small interfering RNAs (siRNAs) play important roles in gene regulation and defense responses against transposons and viruses in eukaryotes. These small RNAs generally trigger the silencing of cognate sequences through a variety of mechanisms, including RNA degradation, translational inhibition, and transcriptional repression. In the past few years, the synthesis and the mode of action of miRNAs and siRNAs have attracted great attention. However, relatively little is known about mechanisms of quality control during small RNA biogenesis as well as those that regulate mature small RNA stability. Recent studies in Arabidopsis thaliana and Caenorhahditis elegans have implicated 3′-to-5′ …

Mining The Bitter Melon (Momordica Charantia L.) Seed Transcriptome By 454 Analysis Of Nonnormalized And Normalized Cdna Populations For Conjugated Fatty Acid Metabolism-Related Genes, Peizhen Yang, Xiangjun Li, Jay M. Shockey, Edgar B. Cahoon

Center for Plant Science Innovation: Faculty Publications

Background: Seeds of Momordica charantia (bitter melon) produce high levels of eleostearic acid, an unusual conjugated fatty acid with industrial value. Deep sequencing of non-normalized and normalized cDNAs from developing bitter melon seeds was conducted to uncover key genes required for biotechnological transfer of conjugated fatty acid production to existing oilseed crops. It is expected that these studies will also provide basic information regarding the metabolism of other high-value novel fatty acids.

Results: Deep sequencing using 454 technology with non-normalized and normalized cDNA libraries prepared from bitter melon seeds at 18 DAP resulted in the identification of transcripts …

Horizontal Acquisition Of Multiple Mitochondrial Genes From A Parasitic Plant Followed By Gene Conversion With Host Mitochondrial Genes, Jeffrey P. Mower, Saša Stefanović, Weilong Hao, Julie S. Gummow, Kanika Jain, Dana Ahmed, Jeffrey D. Palmer

Center for Plant Science Innovation: Faculty Publications

Background: Horizontal gene transfer (HGT) is relatively common in plant mitochondrial genomes but the mechanisms, extent and consequences of transfer remain largely unknown. Previous results indicate that parasitic plants are often involved as either transfer donors or recipients, suggesting that direct contact between parasite and host facilitates genetic transfer among plants.

Results: In order to uncover the mechanistic details of plant-to-plant HGT, the extent and evolutionary fate of transfer was investigated between two groups: the parasitic genus Cuscuta and a small clade of Plantago species. A broad polymerase chain reaction (PCR) survey of mitochondrial genes revealed that at …

A Putative Rna-Binding Protein Positively Regulates Salicylic Acid–Mediated Immunity In Arabidopsis, Yiping Qi, Kenichi Tsuda, Anna Joe, Masanao Sato, Le V. Nguyen, Jane Glazebrook, James R. Alfano, Jerry D. Cohen, Fumiaki Katagiri

Center for Plant Science Innovation: Faculty Publications

RNA-binding proteins (RBP) can control gene expression at both transcriptional and post-transcriptional levels. Plants respond to pathogen infection with rapid reprogramming of gene expression. However, little is known about how plant RBP function in plant immunity. Here, we describe the involvement of an RBP, Arabidopsis thaliana RNA-binding protein-defense related 1 (AtRBP-DR1; At4g03110), in resistance to the pathogen Pseudomonas syringae pv. tomato DC3000. AtRBP-DR1 loss-of-function mutants showed enhanced susceptibility to P. syringae pv. tomato DC3000. Overexpression of AtRBP-DR1 led to enhanced resistance to P. syringae pv. tomato DC3000 strains and dwarfism. The hypersensitive response triggered by P. syringae pv. tomato DC3000 …

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 …

The Influence Of Nutrients And Physical Habitat In Regulating Algal Biomass In Agricultural Streams, Mark D. Munn, Jeffrey Frey, Anthony Tesoriero

United States Geological Survey: Water Reports and Publications

This study examined the relative influence of nutrients (nitrogen and phosphorus) and habitat on algal biomass in five agricultural regions of the United States. Sites were selected to capture a range of nutrient conditions, with 136 sites distributed over five study areas. Samples were collected in either 2003 or 2004, and analyzed for nutrients (nitrogen and phosphorous) and algal biomass (chlorophyll a). Chlorophyll a was measured in three types of samples, fine-grained benthic material (CHLFG), coarse-grained stable substrate as in rock or wood (CHLCG), and water column (CHLS). Stream and riparian habitat were characterized at each site. TP ranged from …

The Seed, Bob Henrickson, Justin R. Evertson

Nebraska Statewide Arboretum: Publications

Too often, groundcovers are not considered when new landscape plantings are installed. Traditionally, the soil surface of new planting beds that incorporate trees, shrubs and herbaceous perennials is covered with a 2-3” layer of organic mulch. The organic mulch helps to conserve moisture, control weeds and give the landscape a uniform, finished look. However, it usually takes a number of years before the plants mature, prompting a yearly top-dressing of mulch to keep the open areas covered. This yearly addition of mulch can be relatively expensive and excessive mulch can build up on the soil. It can also be a …

Nebline, January 2010

NEBLINE Newsletter Archive from Nebraska Extension in Lancaster County

Feature: Tips for Positive Interactions with Tweens

Farm Views

Horticulture

Food & Fitness

Home & Family Living

Environmental Focus

Urban Agriculture

4-H & Youth

Community Focus

Extension Calendar

Nutrition Education Program

Family and Community Education (FCE) Clubs

and other extension news and events

Annual Report Special Pullout Section