Botany Commons^™

Is Climate Change Causing The Range Contraction Of Cape Rock-Jumpers (Chaetops Frenatus)?, Gregory D. Duckworth, Raquel A. Garcia, Rheinhardt Scholtz, Res Altwegg

Department of Agronomy and Horticulture: Faculty Publications

Species distribution models often suggest strong links between climate and species' distribution boundaries and project large distribution shifts in response to climate change. However, attributing distribution shifts to climate change requires more than correlative models. One idea is to examine correlates of the processes that cause distribution shifts, namely colonization and local extinction, by using dynamic occupancy models. The Cape Rock-jumper (Chaetops frenatus) has disappeared over most of its distribution where temperatures are the highest. We used dynamic occupancy models to analyse Cape Rock-jumper distribution with respect to climate (mean temperature and precipitation over the warmest annual quarter), …

Factors Affecting California Grassland Biodiversity: Two Case Studies, Nora Bales

Master's Theses

Biodiversity loss over the last century has been significant and is projected to increase. Biodiversity loss is accelerating due to climate change and habitat loss and degradation. Biodiversity supports key ecosystem services including pollination services, climate regulation, and water filtration. Biodiversity conservation is a top priority for land managers and researchers, however many ecological studies with practical applications lack a thorough understanding of the soil environment in their study system. We conducted two case studies integrating soil and plant data to answer management questions. The first case study investigated the relationship between a threatened plant, Hooveria purpurea var. purpurea and …

Dicamba Off-Target Movement From Applications On Soybeans At Two Growth Stages, Greg R. Kruger, Guilherme S. Alves, Kasey Schroeder, Jeffrey A. Golus, Daniel B. Reynolds, Darrin M. Dodds, Ashli E. Brown, Bradley K. Fritz, Wesley C. Hoffmann

Department of Agronomy and Horticulture: Faculty Publications

The objective of this study was to evaluate dicamba off-target movement during and after applications over soybean at two growth stages. Dicamba-tolerant soybean [Glycine max (L.) Merr.] at V3 and R1 growth stages in Nebraska and Mississippi fields were treated with diglycolamine salt of dicamba (560 g ae ha⁻¹), potassium salt of glyphosate (1260 g ae ha⁻¹), and a drift-reducing adjuvant (0.5% v v⁻¹). Filter papers positioned outside the sprayed area were used to determine primary movement and air samplers positioned at the center of sprayed area were used to calculate dicamba flux …

A Follow-Up Survey To Assess Stakeholders’ Perspectives On Weed Management Challenges And Current Practices In Nebraska, Usa, Shawn T. Mcdonald, Debalin Sarangi, Jennifer M. Rees, Amit J. Jhala

Department of Agronomy and Horticulture: Faculty Publications

Stakeholders across the state of Nebraska, USA, were surveyed in 2019–2020 to assess problem weeds and weed management practices in agronomic crops. A total of 420 complete responses were obtained across four Nebraska districts (Northeast, Panhandle, Southeast, and West Central). Accumulated across the state, 65.5% of farmed or scouted crop ground in Nebraska was under no-till production, with the major crops being corn and soybean representing 39.3% and 30.7% of agronomic crop production area, respectively. Palmer amaranth, horseweed, waterhemp, kochia, and giant ragweed were ranked the most problematic weeds. In a 2014–2015 survey, Palmer amaranth was the sixth most problematic …

The Evolving Definition Of Plant Cell Type, Sahand Amini, Jeffrey J. Doyle, Marc Libault

Department of Agronomy and Horticulture: Faculty Publications

In 1665 Robert Hooke, looking at cork through his microscope, discovered that plants are composed of elementary structures he named “cells”. Variation in the expression of a single genome in a complex eukaryotic organism guides the initiation, maturation, physiology, and biochemistry of cells with different shapes and sizes, playing different structural and functional roles in space and time. How many kinds of cells—”cell types”— an organism possesses of course depends on the organism’s cellular complexity, but the plasticity within a cell type fuels the emergence of the concept of cell state (Figure 1). The transition between cell states is driven …

Shortening Harvest Interval, Reaping Benefits? A Study On Harvest Practices In Oil Palm Smallholder Farming Systems In Indonesia, Rosanne E. De Vos, Lisa Nurfalah, Fatima A. Tenorio, Ya Li Lim, Juan Pablo Monzon, Christopher R. Donough, Hendra Sugianto, Asri A. Dwiyahreni, Nurul L. Winarni, Nadia Mulani, Gilang Ramadhan, Muhammad Ali Imran, Antonius P. Tito, Pandu Sulistiawan, Muhammad Khoirul, Rana Farrasati, Iput Pradiko, Patricio Grassini, Maja Slingerland

Department of Agronomy and Horticulture: Faculty Publications

CONTEXT: Smallholders are responsible for a large share of global palm oil production. Yet, in Indonesia, the main palm oil producing country, smallholders’ yields remain low. Better management practices, including short harvest interval (HI, the number of days between two harvest rounds), could help to raise smallholder yields. However, at present, HI is long in smallholder fields and the drivers underlying this phenomenon are poorly understood.

OBJECTIVE: We explored agronomic, socio-economic, and institutional factors that underlie harvesting practices in independent oil palm smallholder farming systems in Indonesia to assess scope for sustainable intensification through shorter HI and reduced …

Nutritional Profile And Health Benefits Of Stevia Rebaudiana Bertoni: An Updated Review, Ishrat Fatima, Mubashrah Munir, Sehrish Sadia, Akash Tariq, Rahmatullah Qureshi

Journal of Bioresource Management

Aim of this comprehensive review is to document the up-dated data about pharmaceutical potential of Stevia rebaudiana Bertoni with special focus on its antioxidant activity. A total of 184 research articles were reviewed and five research engines were used to collect the data. The S. rebaudiana (Asteraceae) is indigenous to South America, now cultivated in many countries worldwide to be used as a natural bio-sweetener. Various nutritionally and medically important bioactive compounds such as diterpene glycosides, fatty acids, alkaloids, tannins, saponins, anthraquinones, phenolics, flavonoids, carbohydrates, carotenoids, steroids, polysaccharides and other phytochemicals constitute chemical composition of Stevia. Owing to the …

Characterization Of Nacl Stress In Young Bismarckia Palm (Bismarckia Nobilis), Muhammad Afzal Naeem, Iqra Hanif, Midrar Ullah, Muhammad Hassaan Khan, Tahmina Nazish

Journal of Bioresource Management

Salinity is a major problem caused by the accretion of excess salts composites in the form of ions like sodium (Na⁺), potassium (K⁺), calcium (Ca²⁺), magnesium (Mg²⁺) and chloride (Cl^-). The possible out-turns of the salinity on the morphology; physiology and biochemical variables of bismarckia palm (Bismarckia nobilis) were investigated in this study. The seedlings of bismarckia palm were grown in pots and periodically irrigated with various concentrations of NaCl solution to assess the various biological variables at the regular intervals. The experiment was performed by following the …

Exotic Herbivores And Fire Energy Drive Standing Herbaceous Biomass But Do Not Alter Compositional Patterns In A Semiarid Savanna Ecosystem, Virginia D. Preiss, Carissa L. Wonkka, Devan A. Mcgranahan, Alexandra G. Lodge, Matthew B. Dickinson, Kathleen L. Kavanagh, Heath D. Starns, Douglas R. Tolleson, Morgan L. Treadwell, Dirac L. Twidwell Jr, William E. Rogers

Department of Agronomy and Horticulture: Faculty Publications

Questions: Fire regime alterations are pushing open ecosystems worldwide past tipping points where alternative steady states characterized by woody dominance prevail. This reduces the frequency and intensity of surface fires, further limiting their effectiveness for controlling cover of woody plants. In addition, grazing pressure (exotic or native grazers) can reinforce woody encroachment by potentially reducing fine-fuel loads. We investigated the effects of different fire energies on the herbaceous plant community, together with mammalian wildlife herbivory (exotic and native combined) exclusion, to inform best management practices.

Location: Texas semi-arid savanna, southern Great Plains, USA.

Methods: We conducted an …

Effects Of Annual Weather Variation On Peak Herbaceous Yield Date In Sagebrush Steppe, Jonathan Bates, Dustin Johnson, Kirk W. Davies, Tony Svejcar, Stuart Hardegree

Western North American Naturalist

Interannual climate variability impacts forage yield in semiarid rangelands, but it also affects the timing of peak yields. Knowledge of peak standing crop or yield dates would be useful when planning fieldwork for various research or management activities and for developing more accurate models linking herbage production to climatic variables. In this study, herbaceous yield was measured every 2 weeks (April–August) over an 8-year period in a Wyoming big sagebrush (Artemisia tridentata ssp. wyomingensis) community in southeastern Oregon. Date of peak yield (Julian day) was calculated for morphological groups (tall perennial bunchgrasses, perennial forbs, annual forbs), Sandberg bluegrass …

Soil Seed Bank Composition And Spatial Distribution In A Cheatgrass (Bromus Tectorum L.)–Dominated Rangeland In Colorado, Usa, Ryan W. R. Schroeder, Jayne L. Jonas, M. Nikki Grant-Hoffman, Mark W. Paschke

Western North American Naturalist

Invasion by nonnative annual plants that form prolific seed banks, including Bromus tectorum L. (cheatgrass), throughout western North America is a major natural resource concern. Even with known economic and ecological implications, soil seed banks and their potential to impact ecological restoration in arid and semiarid ecosystems are poorly understood. Quantifying the regenerative potential of the soil seed bank—the living seeds in the soil profile and on the soil surface—can help natural resource managers make decisions to increase the likelihood of restoration success. We analyzed the germinable soil seed bank composition and distribution of a rangeland site in western Colorado …

Evaluation Of Native Plant Communities On Nebraska Game And Parks Commission State Parks, Robert F. Steinauer

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

This report evaluates the Native Plant Communities on Nebraska Game and Parks Commission State Parks East Region, also known as Region 3, which includes much of northeast and extreme eastern Nebraska, including portions of the lower Niobrara, Elkhorn and Platte Rivers and nearly the entire east border formed by the Missouri River. Fifteen state-listed threatened and endangered species have been recorded within the boundaries of Region 3 within the last twenty years. Several of these occupy habitats within major river channels.

Surveyed areas which contained habitat for legally protected species include Dead Timber State Recreation Area, Indian Cave State Park, …

Targeted Sequencing Of The Panicum Miliaceum Gene Space And Genotyping Of Variant Sites From Population Genetics Studies, Combined In A Single Assay, As A Tool For Broomcorn Millet Assisted Breeding, Gabriele Magris, Serena Foria, Silvano Ciani, Dipak K. Santra, Ombretta Polenghi, Virna Cerne, Michele Morgante, Gabriele Di Gaspero

Department of Agronomy and Horticulture: Faculty Publications

Broomcorn millet (Panicum miliaceum L.) is a prehistorical cereal, today cultivated as a minor crop with low yields but with a renewed interest for its high water use effciency and gluten-free grains. To reverse the downward trend in broomcorn millet cultivation, the crop needs genetic improvement and creation of novel genetic variation to increase productivity. In order to facilitate genomics-assisted breeding, we designed a reduced representation genome-sequencing assay that investigates 1.8% of the nuclear DNA in a targeted and reproducible way, with an intensity of genomic sampling that is a direct function of local recombination rate. We used this …

Indigenous Lakadong Turmeric Of Meghalaya And Its Future Prospects, Manjit Kumar Ray, Dipak K. Santra, Piyush Kumar Mishra, Saurav Das

Department of Agronomy and Horticulture: Faculty Publications

Turmeric (Curcuma longa) has long been used in traditional Indian medicine. India accounts for 80% of total global turmeric production. Lakadong turmeric gets its name from the tiny village of Lakadong, which is located in the foothills of the Jaintia Hills in Meghalaya, India. It is known for having a high curcumin content of more than 7%, as opposed to 2 - 4% in regular varieties. The tribes of this region brought Lakadong turmeric from the forest and domesticated it for medicinal purposes centuries ago. Growth in local coal industries and a gradual decline in the market have …

Isolation Of Arabidopsis Thaliana Plants Homozygous For An Insertional Inactivation Mutation Within Atprp4., Sydney Raitz, Timothy D. Trott

Research in Biology

The AtPRP4 gene in Arabidopsis thaliana has been shown to function in several specific parts of the plant’s cell wall. It is shown to be expressed in the seeds, radicles, roots, leaves, inflorescences, and embryos of Arabidopsis thaliana. These patterns have suggested unique functions for ATPRP4 in determining cell-type-specific wall structure during the development of a plant as well as contributing to defense reactions against physical damage to the plant and pathogen infection within the plant. In this study, a simple DNA prep was performed on the true leaves of Arabidopsis thaliana. Subsequent PCR reactions were performed using …

Examining The Restoration Potential Of Prescribed Fire And Tree Girdling Treatments On A Fire Dependent Ecosystem: Ecosystem Responses And Management Implications, Rebecca Daigle

Masters Theses

Oak savannas have greatly declined since the 1800s and management is needed to maintain these rare community types. A combination of prescribed burns and mechanical thinning are a common practice to increase forb abundance and biodiversity. This study examines the viability of another technique to thin the canopy called girdling, which was used in conjunction with low-intensity prescribed burns. Early summer prescribed burns were conducted in 2017, 2019, and 2021, while girdling treatments were implemented in 2017 and 2019. The study was conducted in Kent County, Michigan at two degraded former oak savanna communities. In 2022, we collected data to …

Insights On The Distribution Of Struthanthus Palmeri Kuijt (Loranthaceae), The Northernmost Species Of The Genus, Mónica I. Miguel-Vázquez, Yasser S. López De Olmos-Reyes, Maria Guadalupe Maldonado-Borja, Rosa Cerros-Tlatilpa

Western North American Naturalist

Struthanthus (Loranthaceae) is native to the Americas, and several species occur in Mexico, some of which are endemic, such as S. palmeri. Within the genus, S. palmeri has the northernmost distribution, inhabiting the arid environments of northwestern Mexico near the border with the United States. In this study, the known distribution of the species was updated. The elevation, hosts, and vegetation types where S. palmeri occurs were compiled to infer its potential distribution, using ecological niche modeling. Based on the results, the endemic status of S. palmeri is reinforced. This taxon occurs in several types of vegetation, from near …

Effect Of Cutting Management On The Forage Production And Quality Of Tepary Bean (Phaseolus Acutifolius A. Gray), Travis W. Witt, Brian K. Northup, Timothy G. Porch, Santos Barrera, Carlos A. Urrea

Department of Agronomy and Horticulture: Faculty Publications

Tepary bean (Phaseolus acutifolius A. Gray) is an underutilized drought tolerant annual legume, originating from the Sonoran Desert, that may be a beneficial forage/hay for beef cattle in the Southern Great Plains of the US (SGP). The SGP has erratic rainfall and periods of intermittent drought exacerbated by high summer temperatures. In 2020 and 2021, a split-plot design was used to evaluate 13 genotypes of tepary bean and a forage soybean (control) at El Reno, OK, USA to compare production of plant biomass and forage nutritive value parameters under seven harvest regimes. Genotypes were used as the main plot …

Investigating The Role Of Plant Traits And Interactions In Emergent Wetland Nutrient Removal, Andrew Ryan Sample

Theses and Dissertations

Increasing wetland restoration in the Lower Mississippi Alluvial Valley has been identified as a method to reduce nutrient loading in the Gulf of Mexico. Wetlands have historically been used to treat water through processes facilitated by wetland plants, and relatively few species and plant traits have been identified as important in carrying out these processes. This study focuses on some of those species and traits and aims to identify species differences and plant traits that may be important for wetland nutrient mitigation. Chapter I provides background information on nutrient pollution, wetland biogeochemical mechanisms for nutrient sequestration, and the focal species …

Reproductive Ecology And Bee Associates Of Packard’S Milkvetch (Astragalus Packardiae), A Rare Plant Endemic To Southwestern Idaho, Justin R. Fulkerson, C. Lynn Kinter

Western North American Naturalist

Conservation of rare plants is dependent on identifying mechanisms that limit their population or persistence. Successful pollination of flowers is one life history trait that is often limiting in plants occurring in fragmented landscapes. We studied pollinator associates and seed production in Astragalus packardiae (= A. cusickii var. packardiae, Packard’s milkvetch), a narrow endemic that is imperiled as a result of nonnative annual grasses, increased wildfire, recreational off-highway vehicle use, and livestock use. We used pollinator exclusion bags to examine the breeding system of Packard’s milkvetch. We collected and videotaped floral visitors to determine the makeup of the associates …