Life Sciences Commons^™

Quantifying The Carbon Stored And Sequestered By The Trees On Pomona College’S Campus, Paola A. Giron-Carson

Scripps Senior Theses

We are experiencing a climate crisis that must be confronted with strategic mitigation. Pomona College contributes to the climate crisis through its emissions for which there is a baseline record. However there is no baseline record of the climate mitigation currently performed by the trees on Pomona’s campus through carbon storage. This study seeks to determine a current baseline quantity of carbon stored and sequestrated by Pomona’s trees as well as possible courses of climate mitigation for Pomona College to take. Initial information gathering was conducted through interviews with several stakeholders. This study was conducted using data collected prior to …

Changes In Poplar Digestibility Due To Overexpression Of Laccase Genes, Fnu Arunima

Dissertations, Master's Theses and Master's Reports

Woody biomass, particularly poplar, is a sought-after feedstock for lignocellulosic biofuels because of its year-round availability and high productivity. Because of cell wall components like lignin, poplar is inherently resistant to enzymatic saccharification. The experiment aims to determine whether the controlled overexpression of laccase genes alters the biomass composition and whether it can create poplar that is more digestible than the wildtype.

Three sets of transgenic poplar (Populus tremula x alba) samples were evaluated: laccase 18, laccase 27, and STTM. Laccase 18 samples, an target of miRNA397a was overexpressed along with Laccase 27. Short Tandem target Mimic (STTM) technology …

Propagation, Physiology And Biomass Of Giant Cane (Arundinaria Gigantea) For Conservation And Restoration, Sanjeev Sharm

MSU Graduate Theses

Giant cane (Arundinaria gigantea) is a native species to 22 states in the U.S. The species and its ecosystem are considered critically endangered, and the species has been reduced to 2% of its original extent. The species has a long cultural and conservation history. Large canebrakes were commonly found in Missouri in bottomland forests, stream and riverbanks, and margins of lakes. My research goals were to: 1) examine methods for propagation success from field to greenhouse to field; 2) examine the physiology of cane at one of the few current canebrakes, for greenhouse propagated plants, and field planted …

Phenotypic Evaluation Of Energycane (Saccharum Spp.) Genotypes In Northcentral Mississippi, Wyatt Armistead Eason

Theses and Dissertations

As fossil fuel supplies decrease and concerns of climate change increase, the search for alternative sources of fuel has pushed biomass crops to the forefront of discussion. Saccharum spontaneum readily hybridizes with commercial sugarcane and lends cold tolerance and greater yields to the hybrid progeny, called energycane. Twenty genotypes were tested against an energycane variety (Ho 02-113) as a control. Two locations were tested: the HH Leveck Animal Research Center (planted in 2019), and the Bearden Dairy Research Center (planted in 2020). The Bearden Dairy Research Center yielded significantly higher than the HH Leveck Animal Research Center regarding dry matter …

Using Thermal Units To Predict Biomass Accumulation And Total Nitrogen Uptake For Cover Crops In Arkansas, Mila Victório Pessotto

Graduate Theses and Dissertations

Including cover crops in agricultural production systems is an important management practice. Cover cropping can improve soil health, increase plant-available nitrogen (N), provide surface residue to prevent erosional soil loss, increase water infiltration, and increase weed suppression. Cover crops growth can be predicted using thermal days or growing degree days [GDD] similar to commodity crops such as corn (Zea mays L.) or rice (Oryza sativa). Growing degree day calculations are a well-known tool to predict crop growth stage or development stage and can be adapted for use in any plant species, including cover crops. Identifying and developing the relationship between …

Native Species For Biomass Production And Roadside Habitat In South Dakota, Jacob Foley

Electronic Theses and Dissertations

Native grasses and forbs are being considered for planting along South Dakota roadsides to create a favorable habitat for wildlife while also allowing landowners a source of forage and biomass production. South Dakota is host to 54,900 hectares (145,000 acres) of right-of-way that are managed by the South Dakota Department of Transportation. Approximately 80% of the roadsides are used by landowners for hay production. Species diversity and potential biomass yield were determined for the current roadside vegetation along four transects (SD Highways 14, 34 and 50) and SD I- 29 between White, SD and Elk Point, SD. Smooth bromegrass (Bromus …

The Effects Of Elevated Co2 Levels On Broad Bean, Vicia Faba, Growth/Defense Tradeoffs, Harley B. Kitching

Honors College Theses

Atmospheric changes, associated with global climate change, are increasing at an unprecedented rate. Plants generally display higher rates of growth in response to elevated CO₂ levels, but this response varies among species. In addition, very little is known about how plant growth/defense tradeoffs will be altered by increasing CO₂ levels. By raising Broad bean, Vicia faba L., plants under ambient (400 ppm) and elevated (900 ppm) levels of CO₂, it was shown that atmospheric composition directly altered plant growth/defense tradeoffs. Plants grown under elevated CO₂ had lighter stem weights but greater numbers of extrafloral nectaries …

Long-Term Impacts Of Fuel Treatments On Tree Growth And Aboveground Biomass Accumulation In Ponderosa Pine Forests Of The Northern Rocky Mountains, Kate A. Clyatt

Graduate Student Theses, Dissertations, & Professional Papers

In western North America, many low-elevation, dry forest types historically experienced frequent, low-severity fires. However, European settlement and fire suppression policies have contributed to over a century of fire exclusion, substantially altering forest structure and composition. There is considerable interest in restoring fire resilient characteristics to these forests through fuel reduction treatments. One limitation of current research on the impacts of fuel treatments is treatment longevity, as few studies have been able to quantify long-term responses to commonly applied treatments. This research evaluated tree growth and aboveground biomass responses 23 years after treatment in two silvicultural installations with different underburning …

Production And Harvest Of Microalgae In Wastewater Raceways With Resource Recycling, Alexander Colin Roberts

Master's Theses

Microalgae can be grown on municipal wastewater media to both treat the wastewater and produce feedstock for algae biofuel production. However the reliability of treatment must be demonstrated, as well as high areal algae productivity on recycled wastewater media and efficient sedimentation harvesting. This processes was studied at pilot scale in the present research.

A pilot facility was operated with nine CO₂-supplemented raceway ponds, each with a 33-m² surface area and a 0.3-m depth, continuously from March 6, 2013 through September 24, 2014. The ponds were operated as three sets of triplicates with two sets continuously fed …

Enhancing The Sustainability Of Integrated Biofuel Feedstock Production Systems, Amanda Joy Ashworth

Doctoral Dissertations

As use of second-generation biofuel crops increases, so do questions about sustainability, particularly their potential to affect fossil energy consumption and greenhouse gas emissions. Nitrogen (N)-fixing legumes interseeded into switchgrass (Panicum virgatum L.) may be an alternative to inorganic fertilizer in forage-feedstock systems. Research herein is divided into four general experiments: I). N replacement and feedstock impacts from legume intercrops and biochar in switchgrass; II). N-fixation rates in intercrop systems; III). impacts of biofuel systems under enhanced climate change; and, IV). projected sustainability of regional switchgrass production. Approaches included: characterization of feedstock/forage quality traits based on legume, biochar and …

Diallel Analysis Of Biomass And Ethanol Yield In Leaves Versus Stems Of Lowland Switchgrass, Alexandria Christina Desantis

Masters Theses

Switchgrass (Panicum virgatum L.) is a warm season perennial grass used widely as a forage crop. This research seeks to address improving biomass yield and predicted ethanol yield through certain traits by the following objectives: (1) differences in average biomass and predicted ethanol yields from leaves versus stems, (2) genetic variance and heritability estimates of biomass and ethanol yield traits (3) general (GCA) and specific combining ability (SCA) among the five parents for biomass and ethanol yield, and (4) correlations between agronomic and morphological traits. Five parents with varying morphological traits were crossed in a diallel design, excluding selfs. …

Genetic Variability For Biomass Yield, Yield Components, And Ethanol Yield Among Half-Sibs Of Switchgrass, Eifion Wyn Hughes

Masters Theses

For bioenergy crops to be an economical alternative to fossil fuels, rapid biological and technological advancements will need to occur. Some advancements can be accomplished by producing new switchgrass (Panicum virgatum L.) varieties with higher biomass and ethanol yields. The objective of this research was to quantify biomass and ethanol yield potential of four F₁ [F1] half-sib populations for future variety development as a bioenergy crop.

The four parental lines were PI 421999 (AR), PI 607837 (TX), PI 421552 (Cimarron), and Exp. # NSL-2001-1 (OK). Seed for one hundred and forty F₁ [F1] half-sib progeny were produced …

Switchgrass Yield And Quality With Multiple Fertilizer Applications And Harvest Dates, Thomas Clarkson Keene

Theses and Dissertations--Plant and Soil Sciences

Switchgrass (Panicum virgatum L.) is an important native warm-season grass for biomass and forage production in the U.S. This research determined the effect of fertilizer type (conventional, manure, and biosolids) and rate on switchgrass biomass yield and forage quality. Fertilizers were added at 0, 33, 67, 100, and 134 kg N ha^-1 on established stands of ‘Kanlow’ switchgrass in three northeastern Kentucky counties. Soils across sites ranged from recently cleared forestland (low pH, P, and K) to productive cropland (high pH, P and K). Stands were sampled for forage nutritive value in June, simulating a hay harvest. Nutritive …

Forage And Biomass Dual-Purpose Harvest System Using Native Warm-Season Grasses, David Weston Mcintosh

Masters Theses

There has been increasing interest in utilizing native warm-season grasses (NWSGs), especially switchgrass, as a biomass feedstock for cellulosic ethanol production. Millions of hectares of crop and pasture in the mid-South are forecast to potentially be planted with switchgrass for biomass feedstock production. This could have a substantial impact on the region’s cattle industry, reducing forage production hectares. This study was conducted to determine the effect of early season harvest timing on forage and biomass of NWSGs designed for use in cellulosic ethanol production. The over-all hypothesis was to determine if an early forage harvest can be included in a …

Small Mammal Populations In Switchgrass Stands Managed For Biomass Production Compared To Hay And Corn Fields In Kentucky, Laura Mary Jane Schwer

University of Kentucky Master's Theses

Switchgrass (Panicum virgatum), a native warm-season grass, has been investigated as a renewable energy crop that may provide viable wildlife habitat. This study investigated small mammal populations in switchgrass, hay, and corn to assess the relative habitat quality. Four, three-night trapping sessions were conducted at four locations in Kentucky using Sherman livetraps. Trapping occurred in spring (before first hay harvest), summer, fall (before switchgrass and corn harvest), and winter (post-harvest). Relative abundance of small mammals, calculated using a capture per unit effort index (per 100 trapnights), and mean taxonomic richness were used to compare habitats. Switchgrass had a …

Drought Response Of Populus Transformed With Stress Response Transcription Factors, Alina S. Campbell

Masters Theses

The economic feasibility of producing biomass-based fuels requires high-yielding feedstocks to supply biomass to biorefineries. Populus trees are a potential biomass feedstock due to their high yield, but their high water requirement limits productivity under drought conditions.

The number of genes controlling drought tolerance, and the long generation time for perennial species, slows cultivar development. Accelerated domestication proposes using the sequenced Populus genome to quickly incorporate target traits into productive clones by transgenesis.

Six putative drought tolerance transcription factors: DREB2A, DREB2B, AtMYB, AREB1/ABF2, MYB, and NAC, had been previously identified and manipulated in eastern cottonwood (Populus deltoides). Three …

Fine Root Biomass Distribution And Production Along A Barrier Island Chronosequence, Mark Jeffrey Stevenson

Biological Sciences Theses & Dissertations

Fine roots play an important role in community development on barrier islands. Fine roots can influence nutrient losses from the soil environment along with regulating water loss based on their distribution and concentration (Nobel et al., 1989; Gleeson and Tilman, 1990). A sequential coring method was used to determine fine root biomass and total biomass along a chronosequence of barrier island dunes and swales on the Virginia Coast Reserve - Long Term Ecological Research Site. Fine root production and the effects of nitrogen fertilization were also examined using an ingrowth core method along the chronosequence. Live fine root biomass, total …

Aboveground Biomass And Net Primary Production Along A Virginia Barrier Island Dune Chronosequence, John Joseph Dilustro

Biological Sciences Theses & Dissertations

Aboveground biomass was examined along a chronosequence of dune communities on Hog Island, a Virginia Coast Reserve LTER site. The dominant species were Ammophila breviligulata and Spartina patens. Aboveground biomass was harvested monthly from ten quadrats on dunes 6, 24, 36, and 120 years old. Sampling was conducted from April to November 1993. Biomass values were greater for younger dunes. Total aboveground biomass decreased with increasing site age and ranged from 152 g m^-2 on the 120 year old dune to 205 g m^-2 on the 6 year old dune in October 1993. Spartina patens biomass was …