Botany Commons^™

Microbial Response To Biodegradable Mulch: Can Degradation Rate Be Accelerated By Management?, M. Benjamin Samuelson

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

Single-use, petroleum-based polyethylene mulch is ubiquitous in certified organic mulched vegetable systems, representing a broken nutrient cycle and a waste concern. Current organic-allowable biodegradable mulches cannot match the performance of polyethylene, in part because of the requirements that they contain 100% bio-based feedstock, and biodegrade within two years after soil incorporation. It is valuable to understand whether management can influence postharvest degradation rate of mulch films. Two biodegradable mulches: a potentially organic nonwoven polylactic acid and wood particle prototype (PLA), and a widely-adopted non-organic starch/copolymer blend, Bio360® (BLK), were used in field trials in two distinct ecoregions of Nebraska, at …

Investigating Parental Effects On End-Use Quality In Hard Winter Wheat (Triticum Aestivum L.) Hybrids, Anthony Delaney

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

To optimize the performance and marketing of hybrid wheat, breeders need to understand the impact parents have on end-use quality. The goal of this study was to investigate the inheritance of end-use quality traits of hard winter wheat reciprocal hybrids produced by Easterly (2017). The 2016 analysis included 71 reciprocal hybrid combinations from 13 parents and the 2017 analysis included 79 reciprocal hybrid combinations from 14 parents. The reciprocals were composed of crosses between the top performing and bottom performing parents with respect to end-use quality as quantified by a Mixograph, a SDS sedimentation assay, and a SDS-SRC hybrid assay. …

Rust And Viral Mosaic Diseases In Biofuel Switchgrass, Anthony A. Muhle

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

Switchgrass (Panicum virgatum L.) is a perennial warm-season monocot that is indigenous to locations in North America east of the Rocky Mountains, and is considered a model grass for biofuel feedstock production. As switchgrass production increases, diseases pose a potential threat to biomass production and ethanol extraction. The two predominant switchgrass diseases in Nebraska are rust caused by Puccinia spp. and a viral mosaic disease caused by Panicum mosaic virus (PMV) and its associated Satellite panicum mosaic virus (SPMV). In this thesis, one study determined how SPMV affects PMV infection and systemic spread in two populations of switchgrass at different …

Hormonal Signaling Induced In Soybean By Lysobacter Enzymogenes Strain C3, Jessica C. Walnut

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

The biological control bacterium Lysobacter enzymogenes strain C3 has been shown to suppress fungal diseases by producing a suite of lytic enzymes and antimicrobial secondary metabolites. Previous studies have found that C3, when applied to grass and cereal plants, also is capable of inducing local and systemic resistance against fungal pathogens. It is unknown, however, whether the bacterium has the ability to induce resistance in dicots and what signaling pathways are involved. This study assessed the ability of C3 to trigger local and systemic induced resistance responses in soybean (Glycine max ‘Williams82’) by analyzing relative expression of salicylic acid …

B.R. Wells Arkansas Rice Research Studies 2018, R. J. Norman, K. A.K. Moldenhauer

Arkansas Agricultural Experiment Station Research Series

No abstract provided.

The Effects Of Clipping On The Biomass Production Of Native Warm Season Grasses On Reclaimed Abandoned Coal Mine Soils, James A K Daniel

Electronic Theses & Dissertations

THE EFFECTS OF CLIPPING ON THE BIOMASS PRODUCTION OF NATIVE

WARM SEASON GRASSES ON RECLAIMED

ABANDONED COAL MINE SOILS

James A K Daniel

Strip mining leaves behind highly disrupted plant and soil communities. Mined land reclamation returns the land back to a natural or economically usable state, however, reclamation cannot completely restore the soils to their original state. Subsequently, normal frequencies of management practices may not be as effective as in undisturbed soils. Understanding how the severity of soil disturbance affects plant production is important for habitat rehabilitation and determining effective management techniques to be implemented following reclamation. This project …

The Weed Flora Of California: A Checklist, James P. Smith Jr

Botanical Studies

No abstract provided.

How Do Ecological Resilience Metrics Relate To Community Stability And Collapse?, Caleb P. Roberts, Dirac L. Twidwell Jr, David G. Angeler, Craig R. Allen

Department of Agronomy and Horticulture: Faculty Publications

The concept of ecological resilience (the amount of disturbance a system can absorb before collapsing and reorganizing) holds potential for predicting community change and collapse—increasingly common issues in the Anthropocene. Yet neither the predictions nor metrics of resilience have received rigorous testing. The crossscale resilience model, a leading operationalization of resilience, proposes resilience can be quantified by the combination of diversity and redundancy of functions performed by species operating at different scales. Here, we use 48 years of sub-continental avian community data aggregated at multiple spatial scales to calculate resilience metrics derived from the cross-scale resilience model (i.e., cross-scale diversity, …

Estimating Live Fuel Moisture Using Smap L-Band Radiometer Soil Moisture For Southern California, Usa, Shenyue Jia, Seung Hee Kim, Son V. Nghiem, Menas Kafatos

Mathematics, Physics, and Computer Science Faculty Articles and Research

Live fuel moisture (LFM) is a field-measured indicator of vegetation water content and a crucial observation of vegetation flammability. This study presents a new multi-variant regression model to estimate LFM in the Mediterranean ecosystem of Southern California, USA, using the Soil Moisture Active Passive (SMAP) L-band radiometer soil moisture (SMAP SM) from April 2015 to December 2018 over 12 chamise (Adenostoma fasciculatum) LFM sites. The two-month lag between SMAP SM and LFM was utilized either as steps to synchronize the SMAP SM to the LFM series or as the leading time window to calculate the accumulative SMAP SM. …

Identification Of Loci Controlling Adaptation In Chinese Soya Bean Landraces Via A Combination Of Conventional And Bioclimatic Gwas, Ying-Hui Li, Delin Li, Yong-Qing Jiao, James C. Schnable, Yan-Fei Li, Hui-Hui Li, Huai-Zhu Chen, Hui-Long Hong, Ting Zhang, Bin Liu, Zhang-Xiong Lui, Qing-Bo You, Yu Tian, Yong Guo, Rong-Xia Guan, Li-Juan Zhang, Ru-Zhen Chang, Zhiwu Zhang, Jochen Reif, Xin-An Zhou, Patrick S. Schnable, Li-Juan Qiu

Department of Agronomy and Horticulture: Faculty Publications

Landraces often contain genetic diversity that has been lost in modern cultivars, including alleles that confer enhanced local adaptation. To comprehensively identify loci associated with adaptive traits in soya bean landraces, for example flowering time, a population of 1938 diverse landraces and 97 accessions of the wild progenitor of cultivated soya bean, Glycine soja was genotyped using tGBS. Based on 99 085 high-quality SNPs, landraces were classified into three subpopulations which exhibit geographical genetic differentiation. Clustering was inferred from STRUCTURE, principal component analyses and neighbour-joining tree analyses. Using phenotypic data collected at two locations separated by 10 degrees of latitude, …

An Index To The Families And Genera Treated In Flora Of North America North Of Mexico, James P. Smith Jr

Botanical Studies

No abstract provided.

Rare, Threatened And Endangered Species Of Oregon (2019), Jimmy Kagan, Sue Vrilakas, Eleanor P. Gaines, Lindsey K. Wise, Michael Russell, Cayla Sigrah

Institute for Natural Resources Publications

The Oregon Biodiversity Information Center (ORBIC) is part of the Institute for Natural Resources (INR) located at Portland State University (PSU). ORBIC maintains extensive databases of Oregon biodiversity, concentrating on rare and endangered plants, animals and ecosystems. Since its creation in 1979 as the Oregon Natural Heritage Program, ORBIC has been part of the Natural Heritage network. ORBIC is a constituent member of NatureServe, a non-profit organization with a mission to provide the scientific basis for effective conservation action. NatureServe and Oregon manage data using standards and protocols used across the U.S., Canada, and much of Latin America.

ORBIC has …

Nitrogen Fixation In Roots Of Ceanothus, W. John Hayden

Biology Faculty Publications

Roots are usually out of sight and, therefore, out of mind. But as any good gardener will tell you, it is of utmost importance to understand those unique plant organs, even if their essential functions occur hidden from cursory observation. The red roots of the 2019 VNPS Wildflower of the Year, Ceanothus americanus, are particularly important because they host symbiotic bacteria that perform the essential function of nitrogen fixation. These prominent, knobby, distinctively pigmented roots are also the inspiration for the common name Redroot, applied to many species in the genus.

Solanum Plastisexum, An Enigmatic New Bush Tomato From The Australian Monsoon Tropics Exhibiting Breeding System Fluidity., Angela J. Mcdonnell, Heather B. Wetreich, Jason T. Cantley, Peter Jobson, Christopher T. Martine

Faculty Journal Articles

A bush tomato that has evaded classification by solanologists for decades has been identified and is described as a new species belonging to the Australian “Solanum dioicum group” of the Ord Victoria Plain biogeographic region in the monsoon tropics of the Northern Territory. Although now recognised to be andromonoecious, S. plastisexum Martine & McDonnell, sp. nov. exhibits multiple reproductive phenotypes, with solitary perfect flowers, a few staminate flowers or with cymes composed of a basal hermaphrodite and an extended rachis of several to many staminate flowers. When in fruit, the distal rachis may abcise and drop. A member of …

Review Of A Field Guide To The Natural World Of The Twin Cities By John J. Moriarty, Photography By Siah L. St. Clair, Douglas H. Johnson, Bonnie Sample

The Prairie Naturalist

A Field Guide to the Natural World of the Twin Cities has two foci: natural areas in the Twin Cities of Minnesota and the species that live in each. The geographical scope is the seven counties that envelop Minneapolis and Saint Paul. The author describes nine major habitat types that can be found there: prairie, savanna, big woods, oak woods, wetlands (marshes and swamps), fens and bogs, lakes, rivers, and urban and suburban. It is useful to know that “big woods” are not just woods that are large in extent, but woodlands that occur in Minnesota and western Wisconsin dominated …

Factors Affecting White Bass Abundance In Two Missouri River Reservoirs, William J. Radigan, Mark J. Fincel

The Prairie Naturalist

Annual angler harvest of white bass (Morone chrysops) increased from 1985–2005 in Lake Oahe and Lake Sharpe, two mainstem Missouri River reservoirs in South Dakota. In 2006, harvest rates dropped appreciably in both reservoirs and remained low through 2015. It is hypothesized that a confirmed 2005 columnaris disease outbreak led to reduced annual angler harvest of white bass from both reservoirs. Mean annual angler harvest prior to the outbreak (1985–2005) in Lake Oahe decreased 65% and in Lake Sharpe decreased 57% post outbreak (2006–2015). To assess potential causes of sustained decreased adult white bass abundance in the reservoirs, …

Review Of Gulls Simplified: A Comparative Approach To Identification By Pete Dunne And Kevin T. Karlson, Garrett J. Macdonald

The Prairie Naturalist

The title of Pete Dunne and Kevin Karlson’s new book, Gulls Simplified, may seem like an oxymoron to many birders. Gulls are, after all, one of the most vexing groups of North American birds due to their myriad identification challenges, and many seasoned birders simply “don’t do gulls.” Indeed, Dunne, in the first line of the Introduction (page 13), writes, “Ask any bird-watcher to name the bird group that is most intimidating, and to a man, woman, and tour leader they often shout: GULLS!” The genesis of the book, and the authors’ approach to identification within, arises from the notion …

Incidental Captures Of Plains Spotted Skunks In Central South Dakota, Samantha Fino, Joshua D. Stafford, Aaron T. Pearse, Jonathan A. Jenks

The Prairie Naturalist

The plains spotted skunk (Spilogale putorius interrupta) had a historically broad distribution in the central United States, extending from the Mississippi River west to the Rocky Mountains. This subspecies of the eastern spotted skunk (S. putorius) has experienced population declines in recent decades possibly due to habitat loss and reduction of prey through conversion of grasslands and forests to croplands, as well as reductions in abandoned buildings, fence rows, creek bottoms, and wood piles throughout the region (Crabb 1948, Kaplan and Mead 1991, Gompper and Hackett 2005, Sasse 2017). Woody debris provides access to prey, and …

Modifying Succession: A History Of Vegetation Alliances On Swanton Pacific Ranch, Jill Wilson O'Connor

Master's Theses

This thesis conducts historical research into Swanton Pacific Ranch in the County of Santa Cruz, an interdisciplinary facility for education and research managed by Cal Poly’s College of Agriculture, Food and Environmental Sciences. The study seeks to determine whether there have been discernable changes in vegetation alliances (communities), spatially or in type, within a 110-acre Study Area from the early twentieth century to the present day and how the changes compare with other similar historical analyses in California. Historical farming and ranching uses of the area are researched, and two family case studies are presented as paradigms of potential changes …

Leaf Functional Traits As Predictors Of Drought Tolerance In Urban Trees, Sophia Huang

Master's Theses

The services that urban trees provide to human society and the natural environment are widely recognized, but urban trees are in jeopardy due to climate change and urban stressors. With drought as a major threat in many areas, it is important for the future of urban forestry to select species composition based upon performance under water stress. Certain leaf functional traits can help horticulturalists more accurately predict water usage of urban trees. Comprehension through rigorous experimentation is lacking, partly due to the thousands of mostly exotic species. Previous studies suggest that species whose leaves have a denser arrangement of smaller …