Plant Sciences Commons^™

The Long-Term Effects Of Prescribed Fire On Floral Abundance And Bumble Bee Abundance In Mixed-Oak Forests Of Southeastern Ohio, Moses Shafer

Theses, Dissertations and Capstones

Pollinators are declining due to climate change and habitat loss driven by agriculture and urbanization. In fire-adapted ecosystems, fire promotes the biodiversity of plants by creating space, reducing competition, and increasing light and nutrient availability. However, little is known regarding the effects of fire on floral abundance of plants used by Bombus. The overall goal of this project was to assess the long-term effects of fire on floral abundance and Bombus abundance. Our specific questions were: (1) How does fire frequency influence floral abundance?, (2) How does fire frequency influence floral abundance of species specifically utilized by bumble bees?, …

Pcb Remediation In Transitional Floodplain Forests Along The Housatonic River, Soleil Laurin

Scripps Senior Theses

Human development affects natural environments in more ways than climate change, from the introduction of nonnative species and deforestation to pollution and urbanization. This is a case study examining the effects of PCB remediation on transitional floodplain forest along the Housatonic River in Western Massachusetts. The Housatonic River had previously been contaminated with PCBs and portions had been remediated. This study aims to determine the effects this remediation had on transitional floodplain forests, as well as provide a preliminary biodiversity assessment for sites that are planned to be remediated of PCBs by the Environmental Protection Agency. The study was carried …

Developing Best Practices For The Propagation Of Spartina Alterniflora For Use In Salt Marsh Restortaion, Justin Hinson

Electronic Theses and Dissertations

Coastal salt marshes are valuable ecosystems under threat from climate change and sea level rise. Living shorelines offer a promising solution, often incorporating the foundational salt marsh species Spartina alterniflora due to its ability to tolerate natural stressors and maintain sediment stability. However, research suggests that seed-based propagation protocols should be developed on a local scale due to the genetic heterogeneity within and between S. alterniflora populations. Here, we attempt to contribute to the development of one such protocol for coastal Georgia S. alterniflora.

In Fall 2021, seeds were collected bi-monthly from four marshes of varying ocean proximity and …

Sherwin Carlquist (1930–2021)—A Botanical Luminary, Thomas S. Elias, Mare Nazaire, Gary D. Wallace, Vanessa E. Ashworth

Aliso: A Journal of Systematic and Floristic Botany

Sherwin Carlquist (1930–2021) was an internationally respected and distinguished botanist who held faculty positions in botany at California Botanic Garden, Claremont Graduate University and Pomona College between 1956 and 1992. His legacy includes major scholarly contributions to plant systematics, plant anatomy, especially wood anatomy, island biogeography, evolutionary and ecological reasoning, and a prolific publication record. A loose collection of paragraphs by those who interacted with him addresses Carlquist's tremendous botanical output, teaching, mentorship, scientific scholarship, and his roles as a colleague and friend.

Fungi Associated With Herbaceous Plants In Coastal Northern California, Greg Huffman

Natural Sciences and Mathematics | Biological Sciences Master's Theses

The presence of fungal species associated with herbaceous plants was monitored in coastal Marin County, California, USA. The research involved a combination of field sampling surveys and data collection using a stratified random design, pathogen identification through microbiological and molecular analysis, and descriptive analysis and ordination of results. A total of two years of repeated sampling (four times a year) was organized to allow for the detection of seasonal differences in pathogen presence on aerial plant parts. The objective of this study was to identify microbial species present on herbaceous plants using ITS1 sequence analysis. Throughout March of 2018 to …

The Mechanisms And Consequences Of Shrub Encroachment On The Virginia Barrier Islands, Lauren K. Wood

Theses and Dissertations

Shrub encroachment is a global phenomenon driven by direct and indirect anthropogenic influence which alters plant communities and ecosystem function. Many studies have investigated drivers and consequences of woody plant establishment, but mesic landscapes are underrepresented in the literature. My objective was to assess the mechanisms of Morella cerifera encroachment into coastal mesic grassland, the potential for self-reinforcement, and consequences on community composition, nutrients, and landscape productivity. I studied temperature and water microclimate modification by Morella cerifera presence and removal to understand ecosystem engineering and community composition changes. Additionally, I examined the influence of shrubs on surrounding grassland species traits …

Landscape Scale: Inter- And Intraspecific Variation In Plant Interactions Along A Stress Gradient In The Sheep Range Of Nevada, Jordan Dowell

UNLV Theses, Dissertations, Professional Papers, and Capstones

Impending threats to shrubland ecosystems, posed by climate change, necessitate niche modeling efforts to project vegetation range shifts. However, efforts often remain unguided by individual-scale interspecific plant interactions. The stress gradient hypothesis posits that facilitation should increase in areas of high abiotic stress, only if the individuals are able to ameliorate the surrounding area via functional traits. The Sheep Range of Nevada was used to assess the role of functional traits as predictors of plant association. Larrea tridentata, Coleogyne ramosissima, and Artemisia nova were selected as shrubs with variable life history strategies and ranges in order to identify general patterns …

Fire And Road Disturbance Impacts On Forest Plant Species And Seed Rain In Table Mountain Fire Arai, Kittitas County, Washington, Jonathan A. Betz

All Master's Theses

Forest communities are in a constant state of change. Disturbance events can alter the physical landscape and create conditions favorable to some species while negatively impacting others. Fire has been a natural, reoccurring source of disturbance in Pacific Northwest forests. Over the past centuries the fire paradigm has changed in favor of fire suppression. Forest roads permit access provide greater access but further fracture forest community’s continuity. The 2012 Table Mountain Fire and road influence have altered the plant community’s seed rain and vegetation. This study measured dispersed seeds and understory vegetation cover as functions of roads and fire intensity. …

Ecological And Genetic Variation Among Populations Of Boechera Caeruleamontana Sp. Nov. (Brassicaceae) From Blue Mountain And Dinosaur National Monumentin Eastern Utah And Western Colorado, Melissa Snyder

Theses and Dissertations

Boechera is a large genus of flowering plants whose taxa are found primarily in North America. Boechera vivariensis (S.L. Welsh) W.A. Weber (the Park rockcress) is restricted to the Uintah Basin on Weber sandstone substrates in the vicinity of Dinosaur National Monument and Blue Mountain. The nomenclature of Park rockcress is significantly impacted by the discovery that the type collections of the taxon represent a rare, apomictic diploid resulting from the hybridization between B. thompsonii and an undescribed sexual diploid (to be called Boechera caeruleamontana sp. nov. Allphin and Windham). As a result, greater information is needed regarding how B. …

Effect Of Seed Morph And Light Level On Growth And Reproduction Of The Amphicarpic Plant Amphicarpaea Edgeworthii (Fabaceae), Keliang Zhang, Jerry M. Baskin, Carol C. Baskin, Xuejun Yang, Zhenying Huang

Biology Faculty Publications

Amphicarpic plants produce aerial and subterranean fruits on an individual plant, and these heteromorphic diaspores give rise to plants that differ in growth and ecology. Amphicarpaea edgeworthii is a summer annual amphicarpic species that grows over a range of light levels. We aimed to compare the response to shading intensity of plants of A. edgeworthii grown throughout their life cycle from aerial seeds (ASP) and from subterranean seeds (SSP). We hypothesized that vegetative and reproductive growth of plants from ASP and SSP respond differently to light. Plants were grown from ASP and SSP under 0, 46, 71 and 90% shading …

Mapping And Analyzing The Spatial Distribution Of Thetribe Triticeae Dumort. (Poaceae) In Turkey, Hakan Mete Doğan, Evren Cabi̇, Musa Doğan

Turkish Journal of Botany

Triticeae Dumort. (Poaceae), or true grasses, the fifth-largest plant family in the world, are of great importance in terms of human life and civilization. Therefore, understanding the spatial distribution of the family members is important for botanists, plant producers, and breeders. Turkey is one of two gene centers of this family. In this study, the spatial distribution of Triticeae in Turkey was mapped in geographic information systems (GIS) by utilizing a large number of specimens collected from 1006 georeferenced sampling sites between 2004 and 2010. Canonical correspondence analysis (CCA) was carried out in order to understand the spatial distribution of …

Friend Or Foe—Light Availability Determines The Relationship Between Mycorrhizal Fungi, Rhizobia And Lima Bean (Phaseolus Lunatus L.), Daniel J. Ballhorn, Martin Schädler, Jacob D. Elias, Jess A. Millar, Stefanie Kautz

Biology Faculty Publications and Presentations

Plant associations with root microbes represent some of the most important symbioses on earth. While often critically promoting plant fitness, nitrogen-fixing rhizobia and arbuscular mycorrhizal fungi (AMF) also demand significant carbohydrate allocation in exchange for key nutrients. Though plants may often compensate for carbon loss, constraints may arise under light limitation when plants cannot extensively increase photosynthesis. Under such conditions, costs for maintaining symbioses may outweigh benefits, turning mutualist microbes into parasites, resulting in reduced plant growth and reproduction. In natural systems plants commonly grow with different symbionts simultaneously which again may interact with each other. This might add complexity …

Small Unmanned Aerial Vehicles (Micro-Uavs, Drones) In Plant Ecology, Mitchell B. Cruzan, Ben G. Weinstein, Monica R. Grasty, Brendan F. Kohrn, Elizabeth C. Hendrickson, Tina M. Arredondo, Pamela G. Thompson

Biology Faculty Publications and Presentations

Premise of the study: Low-elevation surveys with small aerial drones (micro–unmanned aerial vehicles [UAVs]) may be used for a wide variety of applications in plant ecology, including mapping vegetation over small- to medium-sized regions. We provide an overview of methods and procedures for conducting surveys and illustrate some of these applications.

Methods: Aerial images were obtained by flying a small drone along transects over the area of interest. Images were used to create a composite image (orthomosaic) and a digital surface model (DSM). Vegetation classification was conducted manually and using an automated routine. Coverage of an individual species …

Experimental Studies Of The Multitrophic Effects Of Anti-Herbivore Defense In Three Pine Barrens Shrub Species, Elizabeth R. Coffey

Legacy Theses & Dissertations (2009 - 2024)

Plants produce numerous chemical defense compounds in response to herbivory. Induced chemical defenses potentially influence soil dynamics by changing the nutrient ratio of the leaves, which are seasonally shed and contribute to the soil, or by affecting the detritus community through leaching of chemicals in the root zone. Manual clipping was utilized in this study to induce chemical compounds with the goal of examining the secondary effects of induced plant defenses. I removed 25% of the mass of fifteen plants of three different plant species in the Albany Pine Bush annually for two consecutive years. I then compared the soil …

No Accession-Specific Effect Of Rhizosphere Soil Communities On The Growth And Competition Of Arabidopsis Thaliana Accessions, Anna G. Aguilera, Adán Colón-Carmona, Rick Kesseli, Jeffrey S. Dukes

Biology Faculty Publication Series

Soil communities associated with specific plant species affect individual plants' growth and competitive ability. Limited evidence suggests that unique soil communities can also differentially influence growth and competition at the ecotype level. Previous work with Arabidopsis thaliana has shown that accessions produce distinct and reproducible rhizosphere bacterial communities, with significant differences in both species composition and relative abundance. We tested the hypothesis that soil communities uniquely affect the growth and reproduction of the plant accessions with which they are associated. Specifically, we examined the growth of four accessions when exposed to their own soil communities and the communities generated by …

The Response Of Banksia Roots To Change In Water Table Level In A Mediterranean-Type Environment, Caroline Canham

Theses: Doctorates and Masters

For phreatophytic plants to persist in a given habitat they need to maintain a functional connection to the water table, and the capacity for roots to respond to changes in the water table is a key aspect of this. If root growth is limited by season, plants may not be able to grow roots to adjust to changes in the water table at a particular time of the year. The redistribution of roots, particularly the capacity for roots to follow the water table down in summer and autumn months, is vital for phreatophytic plants to maintain a functional connection with …

Micro-Environment And Plant Assemblage Structure On Virginia's Barrier Island "Pimple" Dunes, Brett A. Mcmillan, Frank P. Day

Biological Sciences Faculty Publications

“Pimple” dunes are small, rounded coastal dunes that form along major dune ridges of the barrier islands along the Eastern Shore of Virginia. Although most pimple dunes are small structures ranging between 10 and 20 m in diameter, they have distinct plant assemblages that replicate the upland ecotones of their barrier islands. We examined the relationship between microenvironment, edaphic factors, and plant assemblage structure on pimple dunes. Water availability was an obvious major ecological driver, but we also tested other environmental factors that may correlate with plant assemblage structure. We found distinct assemblage types that segregated themselves by habitat type: …

A Comparison Of Clearcut And Shelterwood Harvesting Effects On Understory Vegetation In Central Virginia Piedmont Forests, Lorelei J. Hartman

Theses & Honors Papers

I compared clearcutting and shelterwood harvesting effects on all understory vegetation (woody and nonwoody) in Piedmont hardwood forests. Clearcutting and shelterwood harvesting are both even.-aged management practices, put in contrast to clearcutting, the shelterwood method retains selected trees as partial canopy. The retained canopy is reported to be beneficial to desired tree species and restrict competition of undesired tree species, grasses and shrubs.·Research comparing the shelterwood method to clearcutting has been limited , particularly in hardwood forests. We collected data on understory plant communities in clearcut, low-leave shelterwood, and mature forest sites (not harvested in

at least 100 years). Percent …

Genetic Markers In Plant Evolutionary Ecology, Mitchell B. Cruzan

Biology Faculty Publications and Presentations

Genetic markers have provided plant ecologists with a method of assessing levels of genetic relatedness among individuals and populations. In recent years a number of techniques based on DNA sequence variation have been developed to complement allozyme methods that are already widely used. Some of these new markers are more variable than protein-based markers, allowing more precise estimates of genetic differences among individuals and populations. Other DNA-based markers are based on organelle genomes that are inherited uniparentally. These cytoplasmic markers can provide a method for assessing the separate effects of seed and pollen dispersal on gene flow within and among …

Dudleya Cymosa Subsp. Costafolia (Crassulaceae), A New Subspecies From The Southern Sierra Nevada, Tulare County, California, Jim A. Bartel, James R. Shevock

Aliso: A Journal of Systematic and Floristic Botany

Dudleya cymosa subsp. costafolia, a new subspecies from the southern Sierra Nevada, Tulare County, California, is described and illustrated. Along with bright yellow flowers, the cespitose plant produces numerous, small rosettes with rib-shaped linear to linear-oblanceolate leaves, which are unique to the subspecies. The authors have searched numerous other rock outcrops, especially limestone, in the general area for additional plants with no success. Dudleya cymosa subsp. costafolia evidently is restricted to a solitary limestone outcrop north of the South Fork of the Middle Fork of the Tule River.

Monardella Stebbinsii (Lamiaceae), A New Serpentine Endemic Species From The Northern Sierra Nevada, Plumas County, California, Clare B. Hardham, Jim A. Bartel

Aliso: A Journal of Systematic and Floristic Botany

Monardella stebbinsii (Lamiaceae ), a new species from the northern Sierra Nevada of Plumas County, California, is described and illustrated. Characterized by ovate leaves, multiple verticillasters per infiorascence, a matlike habit, reddish papery bracts, and purplish-red leaves with a soft white pubescence, the species is not closely related to any other species of the genus. The new species is apparently restricted to the central portion of a serpentine outcrop located north and east of the confluence of the North Fork of the Feather River and its East Branch.

Pflanzengesellchaften Der Mongolei, Werner Hilbig

Erforschung biologischer Ressourcen der Mongolei / Exploration into the Biological Resources of Mongolia, ISSN 0440-1298

First paragraphs of the introduction:

In Fortführung der Forschungsreisen der russischen Floristen und Pflanzengeouraphen im vorigen und Anfang dieses Jahrhunderts wurden erste Expeditionen zur systematischen Erforschung der Naturressourcen der Mongolei in den 20er und 30er Jahren durchgeführt. Sie wurden von der Akademie der Wissenschaften der UdSSR und der Akademie der Wissenschaften der MVR (vorher Wissenschaftliches Komitee der MVR) organisiert. Auch die von der Geographischen GeselIschaft und der Akademie der Wissenschaften der UdSSR durchgeführten Expeditionen zur Erforschung der natürlichen Bedingungen und der Landwirtschaft in der Mongolei schufen Möglichkeiten zur Entwicklung der geobotanischen Forschungsrichtung (vgl. GUBANOV u. HILBIG 1989).

Als erste eigenständi"e …

Dickey-Lincoln School Lakes Project Environmental Impact Statement: Appendix F: Terrestrial Ecosystem Analysis (Supplement), New England Division, United States Army Engineer Division

Dickey-Lincoln School Lakes Project

Construction of the proposed Dickey-Lincoln School Lakes Project in Aroostook County, Maine will result in the isolation of an area of land due to the impoundment behind Dickey Dam. This land area is located between the United States - Canadian border, the Little Black River, the impoundment (elevation = 913 feet), the Big Black River, and the Shields Branch of the Big Black River, and comprises 183,768 acres of land. A previous report (ERT, 1977) determined the forest types within two miles of the impoundment but did not extend to the Canadian border. This report addresses the forest types

Structural Comparisons Of Four Plant Communities In The Great Dismal Swamp, Claire Virginia Dabel

Biological Sciences Theses & Dissertations

Four plant communities in the Great Dismal Swamp, located on the coastal plain in southeastern Virginia, were sampled and estimates of density, basal area and aboveground standing crop biomass were determined, Biomass was estimated as 229,800 kg/ha in the Chamaecyparis thyoides community and as 344,500 kg/ha in the Taxodium distichum community. Biomass for the two hardwood communities, the

Acer-Nyssa community and mixed hardwood (Quercus-Nyssa-Acer-Liriodendron-Liquidamber) community was estimated as 195,700 kg/ha and 194,600 kg/ha respectively and did not differ significantly (P

Annual Pasture And Weed Plant Ecology, B J. Quinlivan

Journal of the Department of Agriculture, Western Australia, Series 4

The purpose of this article is to outline a few basic principles of pasture and weed ecology with particular reference to seed dormancy mechanisms.

These principles apply to many pasture plants and weeds, although their relative importance varies with the particular plants under study.

A Study Of Certain Community Relationships Of Eriogonum Corymbosum Benth In Dc In The Uintah Basin, Utah, Jack D. Brotherson

Theses and Dissertations

Eriogonum corymbosum Benth. in DC is a low-growing perennial shrub which is found in many cold temperate desert shrub regions of Colorado, Utah, and Nevada.. It is a species which grows on numerous soil types and/or geological formations. Specific objectives of the investigation were to study and describe certain community relationships of ten different plant communities where E. corymbosum was found. Each community was sampled to determine the amount of ground cover, percent composition, frequency, and density of each participating species. Physical site factors viz. soil texture, total soluble salts, pH, cation exchange capacity, and amount of calcium, magnesium, potassium, …