Thesis (Ph. D.)--University of Texas at Austin, 2004. / Supervisor: Norma Fowler. Vita. Includes bibliographical references.

Thesis (M.S.) University of Missouri-Columbia, 2006. / The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file (viewed on August 27, 2007) Includes bibliographical references.

Oaks (Quercus spp.) have dominated eastern forests of the United States for centuries; however, current disturbance regimes discourage oak recruitment and allow shade-tolerant mesophytic species (e.g., maples, Acer spp.) to out-compete oaks. I assessed the effects of mesophication on bird communities by examining differences in breeding bird community structure, abundance, and diversity across 8 and 12 deciduous forest stands in southern Illinois during 2009 and 2010, respectively, using line transects, and by examining a 5-year monitoring data set from across the Shawnee National Forest in 2005-2009. I predicted that variation in bird community structure between maple- and oak-dominated forests can be explained by differential availability of foraging niches. Forest stands used in 2009-2010 were separated along a gradient of hard-mast tree composition, which was defined as the percentage of tree basal area in the stand contributed by oaks and hickories (Carya spp.). Linear regression and Akaike's Information Criteria were used to assess habitat-association models for 7 bird community metrics: bird species diversity, species richness, overall abundance, and abundance of aerial foragers, bark gleaners, foliage gleaners, and ground gleaners. Bird species diversity (Shannon-Wiener H') and species richness ranged from 2.97 to 3.15, and 29 to 37, respectively, over both years. Bird species diversity and species richness were best modeled by a negative relationship with % hardmast tree basal area across both years, whereas overall abundance was best modeled by a positive relationship with understory woody stem diversity. Detection rates for foraging guilds were best modeled by various metrics of habitat structure. Aerial foragers, bark gleaners, foliage gleaners, and ground gleaners responded positively to stem density, downed coarse woody debris density, basal area, and stem diversity, respectively. I used non-metric multidimensional scaling (NMDS) and analysis of similarity (ANOSIM) to examine the degree of dissimilarity among bird communities and site type. In 2010, the bird community differed overall, with communities in oak forests tending (P = 0.09-0.11) to differ those in non-oak and mixed-mesophytic sites. Analysis of a 5-year data set yielded similar results. All models tested for bird-species diversity and species richness were competing, suggesting no individual habitat factor was a strong predictor. Overall abundance and abundance of aerial foragers, bark gleaners and foliage gleaners showed negative relationships to hardmast basal area in all years combined. Ground gleaners responded positively to tree diversity. A post-hoc analysis revealed that overall bird abundance and abundance of foliage-, bark- and ground-gleaning guilds responded positively to an index of riparian areas. Resource use during the breeding season may be shifted to mesic habitats, possibly due to increased resource availability in terms of arthropods and water. Results indicated that mesophication may not have the predicted effects on forest-breeding bird communities, and that vegetation structure was more important in determining bird community structure than tree composition in small-scale forest stands during the breeding season. Resident and over-wintering bird species may be most affected by the loss of oaks due to use during time periods when mesic habitats do not supplement resources. Managers should consider maintenance of a diversity of forest types to maximize avian diversity.

The current oak-hickory overstory that exists in the productive uplands of Southern Illinois is a result of a disturbance regime that lasted thousands of years. The species mix that is currently regenerating under this overstory is a consequence of the historic disturbance regime being severely altered in the last century. As the importance and value of the oak-hickory forest type is widely recognized, land managers seek effective ways to ensure the perpetuation of an oak-hickory component in future stands. Across its range, forest management activities are being implemented in an effort to promote oak, with mixed results. The current study was conducted in the eastern portion of the Shawnee National Forest on private land, with the exception of some Burn only and control stands which were located on Forest Service land. Treatments for these stands fell within five distinct groups: TSI, Burn, TSI/Burn, TSI/Harvest, TSI/Harvest/Burn, plus a control group. Data was collected on overstory, regeneration, and site characteristics. The change in height and abundance of oak seedlings across treatment groups was analyzed with an ANCOVA test. The competitive position of oak and hickory seedlings relative to all seedlings was analyzed with an ANOVA test. The results revealed that TSI only may actually put oak regeneration at a disadvantage, possibly because it only increases the amount of light enough to promote shade tolerant species. The TSI/Harvest/Burn group showed potential to increase the size and abundance of oak regeneration, suggesting the need for higher disturbance intensity in order to increase oak regeneration. When competitive position of oak and hickory seedlings were analyzed, the burn only group showed the greatest increase over the control group, reinforcing the idea that fire naturally selects for oak. Management activities should focus on using heavy disturbance to establish oak regeneration, then fire to ensure that they are competitive enough to eventually reach the overstory.

A study was conducted to assess Treaty Oak Community College's (Treaty Oak) accomplishment of its mission in terms of responding to the educational and training needs of the community. A questionnaire was sent to students who were enrolled in a program of study from 1986-1989. This survey was to evaluate the assistance Treaty Oak gives students in reaching their goals, to determine employment or student status and to assess the effectiveness of the academic and student services at Treaty Oak. A second questionnaire was sent to local businesses to evaluate the contribution that Treaty Oak makes in meeting the business community's needs. Evaluation of the treatment is in percentage form.

Red oak (Quercus spp.) acorns provide food for wildlife and are propagules for regeneration of these trees. Annual yield of acorns varies temporally and site-specifically. I examined acorn yield in relation to hydrology and soils of hardwood bottomlands at five sites in the Mississippi Alluvial Valley and a site in the Mississippi Interior Flatwoods Region during fall-winter 2012-2013. Acorn yield varied among sites (mean = 44.9 acorns/m2; SE = 6.7; CV = 14.9%). Duration of flooding during the growing season differed among sites which influenced soil characteristics. Acorn yield varied inversely with number of days sites were inundated during the growing season (R2 = 0.6725; P = 0.0456; n = 6) during 2012-2013. Managers should consider alleviating growing season flooding of red oaks, which may increase acorn yield and sustain red oaks and other bottomland hardwoods.

Survival and growth of two oak species, water oak (Quercus nigra) and swamp chestnut oak (Quercus michauxii), and three planting stocks: 1-0 bareroot, conventional containerized, and EKOgrownTM seedlings were compared for two growing seasons. Conventional containerized seedlings had the best survival. Bareroot seedlings had the second highest survival and EKOTM seedlings had the lowest at the end of two growing seasons. Conventional containerized planting stock exhibited greater groundline diameter (GLD) growth for both species at the end of the first growing season compared to bareroot and EKOTM planting stock. Bareroot seedlings had similar GLD growth to EKOTM seedlings for both years. Conventional containerized seedlings height differed in water oak but did not differ in swamp chestnut oak at the end of year two compared to bareroot seedlings. EKOTM seedlings exhibited severe dieback at the end of both growing seasons and the least amount of height growth.

East Fork Poplar Creek (EFPC) in Oak Ridge, TN was highly contaminated with elemental mercury in the 1950 and 1960. The area is still experiencing the effects of mercury contamination, and researchers are searching for ways to remediate the EFPC. One possible mechanism for bioremediation is the use of biogenic Mn oxides to remove heavy metals from water systems. Native Pseudomonas bacteria species were isolated from EFPC in order to examine biogenic Mn oxides production and bioremediation of Oak Ridge slurries. Pseudomonas isolates did produce Mn oxides which bound to mercury, and mercury bound to organic matter significantly decreased. However, after a significant decrease of dissolved mercury, dissolved mercury was cycled back into the water system on day 10. Given a longer experimental timeline, biogenic Mn oxides have the potential to decrease mercury cycling.

The purpose of this study is to determine the amounts of the element sulfur, phosphorus, sodium, potassium, silicon, iron, aluminium, calcium, magnessium, and manganess found in the roots, hearts, sap, leaves, and bark of two plants, the short leaf pine and the blackjack oak.

<p>In 2016, chestnut oak (<em>Quercus prinus</em>) trees across southern Indiana began displaying symptoms of decline disease. In the years following, widespread patches of mortality appeared on slopes and along ridges, prompting the Indiana Department of Natural Resources (IDNR) to investigate. The IDNR noted the presence of <em>Phytophthora cinnamomi </em>on one diseased chestnut oak, leading to the initiation of this study. Our goals were to (1) determine if <em>P. cinnamomi </em>contributed to the widespread decline, (2) determine what site or stand variables were associated with higher rates decline, (3) examine the growth of declining trees prior to the onset of symptoms to determine if drought contributed to decline, and (4) use Forest Service Forest Inventory and Analysis (FIA) data to examine trends in regional chestnut oak mortality.</p> <p>From 2021-2022, we collected thirty fine root and soil samples from declining chestnut oak trees within Morgan-Monroe State Forest, Yellowwood State Forest, and the Hoosier National Forest. Throughout these forests, we established sampling plots within declining and healthy chestnut oak stands. In each plot we recorded site, stand, and tree level variables, then collected tree cores from two or three chestnut oak trees. Fine root samples were tested for the presence of <em>P. cinnamomi </em>at the Purdue Pathogen and Pest Diagnostic Laboratory (PPDL) in West Lafayette, Indiana.</p> <p>We used binomial linear regression to test for significant (α = 0.05) relationships between site and stand variables and decline, where a binary decline or no decline was used as the response variable. Both basal area increment (BAI) and ring width index (RWI) chronologies were built separately for healthy, declining, and dead chestnut oak trees. We used a paired t-test (α = 0.05) to test for significant differences in 10-year segments of BAI between the three chronologies. Finally, we used linear regression to test for significant (α = 0.05) effects of the standardized precipitation-evapotranspiration index (SPEI) in current and previous year growing seasons on RWI. Chestnut oak mortality volume across the eastern United States was calculated using the EVALIdator tool provided by USDA-FS FIA. Associations between chestnut oak mortality recorded by FIA and several climate and topographical variables were examined using a random forest classification.</p> <p>Out of thirty fine root samples, only one tested positive for the presence of <em>P. cinnamomi</em>, indicating that this decline was not associated with the pathogen. The analysis of site and stand variables revealed a greater chance of decline on east and northeastern facing slopes, with a slight increase in decline likelihood with increasing stand density. There was significantly lower BAI in dead and declining trees long before decline symptoms began, a pattern consistent with previous drought induced declines. We observed a significant relationship between RWI and SPEI in the early growing season (June and 3-month June SPEI) and throughout almost all of the prior year’s growing season (May, June, 3-month June, 3-month July, and 3-month August SPEI). Chestnut oak mortality volume across the eastern US steadily increased from 2006-2020, indicating a region-wide increase in mortality. Our random forest classification indicated the importance of increased precipitation and precipitation timing on chestnut oak mortality.</p> <p>Chestnut oak decline observed in southern Indiana was induced by a series of droughts in 2005, 2007, and 2012. The greater early life BAI of chestnut oak which were impacted by decline revealed that individuals which likely prioritized stem growth over root growth were predisposed to decline and mortality from these droughts. This prioritization could be brought on by genetic differences, favoring rapid height growth in developing even-aged stands, or by an abundance of moisture availability. Our FIA analysis of mortality revealed increased mortality volume across many states from 2006-2020, and that chestnut oak mortality may be related to greater precipitation compared to historic levels. Considering these results, we suspect that chestnut oak which have recently died or are currently declining are likely individuals which lack the root system to endure repeated drought.</p>