Master of Science (MS), Bowling Green State University, 2021, Geology

As a main component of the terrestrial hydrological cycle, evapotranspiration (ET) significantly affects soil moisture, atmospheric water vapor content, plant nutrient absorption, and primary production. Thus, accurate estimation of ET is important to provide a better insight into complex processes of the water balance and plant-water interaction. Temporal and spatial estimation of ET over a large area is possible through remote sensing-based land surface energy balance models. In this study, modified Boreal Ecosystem Productivity Simulator (BEPS), a stomatal conductance-based ET model used to estimate the ET rate in the Lower Maumee River watershed for the 2018 growing season. The study area is crop-dominated with corn (a.k.a. maize), soybean, alfalfa, and winter wheat as the main crop types. Given that corn is a C4 plant, which possesses a water-efficient photosynthesis system, and the rest of the crops in the watershed are C3 plants with a less efficient water-related apparatus, this study explores the possible effect of land cover (LC) changes on ET, when LC is modified from the existing state to a simulated 100% corn-covered area. The goal is to understand how the growth of corn monoculture may impact the water balance of the watershed. The study also explores the impact of a range of stomatal conductance values of crops on the ET rate, and stomatal conductance is a measure of stomata openings and water transpiration. The findings show that increasing the corn coverage to 100% does not significantly impact the ET rate in the watershed (overall increase of ET is 5.05% for July and 3.96% for August). The results also suggest that the modeling scenario with the highest values of stomatal conductance may result in significantly increased ET (up to 24.04% for corn and 5.1% for soybean), and as such it agrees with the thermal-based ECOSTRESS ET product derived and validated over the study area over the same growing season (+/- 0.9 mm/day). This study extends the rese (open full item for complete abstract)

Committee: Anita Simic Milas Ph.D. (Advisor); Ganming Liu Ph.D. (Committee Member); Margaret Yacobucci Ph.D. (Committee Member) Subjects: Ecology; Geology; Hydrology; Remote Sensing

Master of Science in Environmental Science, Cleveland State University, 2020, College of Sciences and Health Professions

Compared to their natural counterparts, trees in urban ecosystems experience distinctive environmental conditions which can be both beneficial and harmful to tree functions and fitness. Thus, the morphological, phenological, and physiological functions of trees in urban ecosystems can be unique and might not be predictable from patterns identified in natural forests where most research on tree ecology has occurred. To better understand how different tree species contribute to ecosystem services in urban environments, we estimated a number of key performance metrics and functional traits for species commonly planted in urban areas. Between April of 2017 and December of 2019, we monitored 42 species of trees across two sites growing in open, urban settings. Radial growth of each individual was measured weekly from April to December using dendrometer bands. Leaf phenology was assessed weekly during leaf development and senescence. Wood phenology was estimated using the RDendrom package in R. Annual C sequestration was estimated using radial growth data, allometric equations (Urban Tree Database), and species-specific wood density and stem C% estimates (TRY database). We also measured several important anatomical, morphological, physiological, and phenological traits. In 2019, we measured a number of canopy characteristics on a smaller subset of individuals (n=137) across 38 species. Lastly, we measured a number of potentially important abiotic covariates, including soil texture, soil pH, canopy light availability, and various topographic variables. We found evidence that performance metrics (basal area growth), canopy characteristics, and functional traits varied significantly among the species in our study. Moreover, the performance metrics and traits which are directly linked to specific ecosystem services, such as aboveground carbon sequestration and drip line leaf area index, also varied significantly among the species in our study. This suggests that particular (open full item for complete abstract)

Committee: Kevin Mueller (Advisor); Emily Rauschert (Committee Member); Thomas Hilde (Committee Member) Subjects: Botany; Ecology; Environmental Science; Statistics; Urban Forestry

Master of Science (MS), Bowling Green State University, 2018, Geology

Evapotranspiration (ET) is a hydrologically and eco-agronomically important process that can be altered by soil properties, crop type and mechanisms of photosynthesis (e.g. C3 and C4), crop status, agricultural practices (crop rotation and monoculture), and meteorology. In particular, corn monoculture, which is widely used in the U.S, may affect over agricultural fields differently than soybean and wheat deu to the different (C4) photosynthesis mechanism, and thus can have an impact on local hydrologic cycle and climate. Satellite observations are the most sophisticated technology to monitor different rates of ET at large scale. This study used data from two satellites, Landsat 8 and Sentinel 2, to examine the capability of combining those data in ET time series to explore the differences between ET rates for C3 (soybean and winter wheat) and C4 (corn) crops. ET was estimated for a study area located in the Western Lake Erie basin for 2016 and 2017 using satellite data and the Boreal Ecosystem Productivity simulator (BEPS), a process based ecosystem model, modified for the agricultural ecosystem. Satellite images (from which land cover/land use data, and leaf area index were generated), weather (Gridmet data), and soil data (SSURGO data) were main inputs to BEPS. In addition, a sensitivity analysis was conducted to estimate ET for different percent increments of the total area covered by corn to the point of becoming a monoculture using synthetically developed land covers and LAI images. For both years, corn and soybean reach the maximum ET rate in the mid-growing season as expected with the peak being somewhat later in the season for soybean. The ET relationship between two sensors was strong during the mid-season (r = 0.95 for July) when LAI was high, and at the end of the season, when many crops were harvested and soil exposed (r = 0.98 for iv October). A high correlation was also observed when data were acquired within a short period of time (open full item for complete abstract)

Committee: Anita Simic Dr. (Advisor); Peter Gorsevski Dr. (Committee Member); Ganming Liu Dr. (Committee Member) Subjects: Agriculture; Agronomy; Earth; Ecology; Environmental Geology; Geobiology; Geology; Remote Sensing

Master of Science (MS), Bowling Green State University, 2014, Geology

Leaf area index (LAI) is an important indicator of ecosystem conditions and an important key biophysical variable to many ecosystem models. The LAI in this study was measured by Leica ScanStation C 10 Terrestrial Laser Scanner (TLS) and a hand-held Li-Cor LAI-2200 Plant Canopy Analyzer for understanding differences derived from the two sensors. A total of six different LAI estimates were generated using different methods for the comparisons. The results suggested that there was a reasonable agreement (i.e., the correlations r > 0.50) considering a total of 30 plots and limited land cover types sampled. The predicted LAI from spectral vegetation indices including WDVI, DVI, NDVI, SAVI, and PVI3 which were derived from Landsat TM imagery were used to identify statistical relationships and for the development of the Bayesian inference model. The Bayesian Linear Regression (BLR) approach was used to scale up LAI estimates and to produce continuous field surfaces for the Oak Openings Region in NW Ohio. The results from the BLR provided details about the parameter uncertainties but also insight about the potential that different LAIs can be used to predict foliage that has been adjusted by removing the wooden biomass with reasonable accuracy. For instance, the modeled residuals associated with the LAI estimates from TLS orthographic projection that consider only foliage had the lowest overall model uncertainty with lowest error and residual dispersion range among the six spatial LAI estimates. The deviation from the mean LAI prediction map derived from the six estimates hinted that sparse and open areas that relate to vegetation structure were associated with the highest error. However, although in many studies TLS has been shown to hold a great potential for quantifying vegetation structure, in this study the quantified relationship between LAI and the vegetation indices did not yield any statistical relationship that needs to be further explore.

Committee: Peter Gorsevski PhD (Advisor); Anita Simic PhD (Committee Member); Kurt Panter PhD (Committee Member); Jeff Snyder PhD (Committee Member) Subjects: Environmental Geology; Geology

Master of Science, The Ohio State University, 2012, Horticulture and Crop Science

Several winegrapes grown in cool climates, including Vitis vinifera Cabernet Franc and Vitis sp. Chambourcin, benefit from crop reduction. The practice promotes timely fruit maturation and can improve fruit quality. Balanced pruning and cluster thinning are the cultural practices used to attain the desired crop load. However, crop reduction by cluster thinning is labor intensive, costly and typically not mechanized for winegrapes. In this study, the practice of early season leaf removal by hand and with a mechanized leaf remover is proposed as an alternate tool to reduce crop level, thereby optimizing crop load and fruit quality. The objectives were to determine the effects of the timing of leaf removal (pre-bloom, bloom, or fruitset) on yield components, crop load, fruit quality, and cold hardiness in Chambourcin and to 2) determine the effects of manual versus mechanical leaf removal at different phenological stages on yield components, growth, crop load, and fruit quality in Cabernet Franc. In Chambourcin, leaf removal at pre-bloom in 2010 and bloom in 2010 and 2011 reduced yield as compared to defoliation at fruitset and control (no removal). Early season leaf removal reduced crop load (Ravaz index) in both years. Defoliation at bloom increased bud lignification in both years and reduced bud injury in fall of 2010. Defoliation at pre-bloom reduced bud injury in winter in one of two years. In Cabernet Franc, manual leaf removal at pre-bloom and mechanical leaf removal at bloom reduced yield. Leaf removal had no negative effects on pH, titratable acidity, soluble solids, or total phenolics in either cultivar in either year. Early season leaf removal can be used to control yield without negatively impacting growth, cluster compactness, disease incidence, fruit composition, or lignification. It is concluded that early season leaf removal is a viable alternative to cluster thinning as a method of yield reduction in Chambourcin. Early season mechanical leaf removal is (open full item for complete abstract)

Committee: Imed Dami Dr (Advisor); Douglas Doohan Dr (Committee Member); Joseph Scheerens Dr (Committee Member); Michael Ellis Dr (Committee Member) Subjects: Agriculture; Horticulture

Master of Science (MS), Ohio University, 2005, Plant Biology (Arts and Sciences)

The restoration of the American chestnut to U.S. forests is currently a subject of much interest. Questions remain about where on the landscape chestnut should be replanted, and the ecophysiological capacity of chestnut at different ontogenetic stages. The goals of the present study were to assess the physiological and leaf characteristics of chestnut and to quantify these characteristics at the seedling, sapling, and mature growth stage. The photosynthetic performance, leaf mass per area, and leaf nitrogen content of chestnut were assessed at sites in Wisconsin and Ohio. Seedlings maximized photosynthesis under high light conditions, a practical result for foresters replanting chestnut. The physiology and leaf characteristics of seedlings and saplings in the understory were similar. Photosynthesis and leaf nitrogen were maximized at the top of the canopy, declining with stand height and light availability. These results will be useful in modeling the carbon dynamics of mature American chestnut forests.

Committee: Kim Brown (Advisor) Subjects: Biology, Plant Physiology

Bachelor of Science, Miami University, 2007, College of Arts and Sciences - Botany

In this study, non-destructive surrogate methods of sampling aboveground plant biomass were compared to actual measured aboveground biomass. The frequency and the percent cover of each species were correlated with species biomass of each plot. The estimated Leaf Area Index (LAI), transmittance of light through the canopy, total additive frequency, and total additive percent cover were each correlated with the total biomass of each plot. Percent cover was the most highly correlated with the biomass of each species, while LAI was the most highly correlated with the biomass of all plants in each plot. In a case study, the methods that had been found to be most closely correlated with biomass also resulted in diversity correlations and richness correlations similar to those correlations with biomass. The additive percent cover of all species within a plot resulted in misleading correlations with diversity when compared to diversity-biomass correlations.

Committee: Martin Henry Stevens (Advisor) Subjects:

Master of Science, Miami University, 2005, Botany

Castanea dentata once dominated the eastern deciduous forest, but was virtually eliminated by the exotic fungus, Cryphonectria parasitica. We compared C. dentata's morphological and leaf chemistry traits to those of formerly co-occurring species. Seedlings of C. dentata, Q. rubra and L. tulipifera were grown in varying light and nitrogen regimes. After four months of growth, we measured specific leaf area, biomass, plant height and leaf nutrient content of each seedling. Castanea dentata attained greater height, biomass and leaves per plant than the other two species in most light treatments (P < .001). Results also revealed several other traits and tradeoffs of the three species. Castanea dentata's ability to accumulate greater biomass and height at the seedling stage of development may explain a great deal about its former dominance. Results also suggest that C. dentata will be able to thrive in a wide variety of intact forests when reintroduction experiments begin.

Committee: M. Henry Stevens (Advisor) Subjects: Biology, Botany