Thesis (Ph. D.)--Institute of Paper Chemistry, 1957. / Includes bibliographical references (p. 96-98).

Thesis (Ph. D.)--Institute of Paper Chemistry, 1952. / Includes bibliographical references (p. 154-157).

Thesis (Ph. D.)--Institute of Paper Chemistry, 1969. / Includes bibliographical references (p. 117-120).

Thesis (Ph. D.)--Institute of Paper Chemistry, 1943. / Bibliography: leaves 69-72.

Managed pine forests are central to the economic vitality of the southeastern US. Over the past fifty years, the productivity of managed pine forests of this region have increased significantly with the development of new silvicultural technologies and the use of improved tree genetic material. Of the pine species present in the southeastern US, loblolly pine has arguably been the most intensively studied and widely planted by forest managers. Efficient operational deployment of improved genetic materials requires an understanding of how possible site conditions and silvicultural treatment may interact to affect maximum yield. There are a wide range of site conditions in the south as the result of regional climate gradients, soil type and soil drainage patterns. On the western edge of loblolly pine’s natural extent, Texas has a drier climate than areas to the east, and in Louisiana, there are also poorly drained Ultisols that are found in areas with little relief and are prone to flooding. However, on the basis of 10-year forest inventory data of pure-family plots from three different sites and under two levels of cultural regime intensity, my study found that superior genotype, Lob 5 from South Carolina, still showed best performance in the Western Gulf area, and high intensive treatment could improve stand growth and resistance to wind damage significantly. Further, my study compared the stand production and dynamics between pure- and mixed-family plots. I found that Lob 5 and Lob 4 showed the growth traits of competitive ideotype, and low intensive treatment increased the deployment effect significantly for competitive ideotype. Finally, my study examined leaf area index (LAI) and foliar nitrogen concentration (foliar N). The result showed that fast growing genotype had lower LAI and foliar N than slow growing one. It indicated that fast growing genotype had high resource use efficiency and nutrient requirement. This research provided critical information to guide industrial forest management in the WG (Western Gulf) area. First, introduced superior genotype continued to show good performance in this area. Second, combination of good genotype and high intensive treatment would increase plantation production significantly. Third, identification of ideotype would increase the accuracy of growth potential estimation in progeny test.

With increasing encroachment on natural communities by anthropogenic activity, it is important to understand the functions of natural ecosystems in an effort to conserve natural areas. A first-hand study of the population dynamics of South Florida Slash Pine (P. elliottii Engelm. var. densa) following a fire event provided insight to its recovery and dispersal following a fire. A natural fire (lightning-induced) occurred in the spring of 2000 at the T. Mabry Carlton, Jr. Reserve, Sarasota County, providing an opportunity to study aspects of slash pine in relation to fire. One objective of my research was to look at dispersal/recruitment conditions and slash pine dynamics in relation to fire. I looked at the varying degrees of tree mortality due to fire at different stands of slash pines. I also looked at the stands in terms of stand composition and spatial arrangement of surviving adults. Finally, I studied how variable seedling establishment and survival was between stands. Few inferences could be drawn between fire and these individual analyses; however, all analyses revealed that at the scale of this study, pine flatwoods are patchy. I also looked at the dispersal of slash pines following a fire event. I modeled my research after Ribbens et al. (1994) and Clark et al. (1998), who took a phenomenological approach to dispersal modeling. This approach involved using distances between adults and seeds/seedlings and fecundity of adults to create dispersal models based on maximum likelihood estimates (MLE). I found that, while I could predict a model within acceptable parameters for most of the stands, more data was needed to predict models that better fit the data. This finding, along with the fact that I recovered no seed data for analysis, suggests factors are contributing to dispersal and recruitment (e.g. cone-crop) that need to be accounted for in the future.

A study was conducted at the Savannah River Site near Aiken, SC to: 1) characterize the spatial patterns of soil and forest floor variables (moisture, pH, soil phosphate, forest floor and soil carbon and nitrogen, and soil available nitrogen), 2) assess the spatial patterns of the plant community, and 3) investigate spatial relationships among the variables and between the variables and woody vegetation. Spatial soil and litter samples were collected on five 0.25 hectare plots, and relationships were explored using Pearson's correlation tests, canonical correlation analysis, variogram modeling and kriging. The average range of spatial autocorrelation for the forest floor variables was >45 m, while that for soil variables was 12 m. Woody stem basal area exhibited spatial autocorrelation at ranges of less than 12 m, and was only weakly correlated with forest floor and soil resource patterns. Few strong spatial correlations among the forest floor and soil variables were observed. The means and variances of the variables were low, and differences in resource levels probably had little impact on the spatial pattern of vegetation. Results indicate a weak, differential effect of species group on litter quality, a weak relationship between large pine trees and soil nitrogen patterns, and a general homogeneity of the stands. / Master of Science

Title from PDF of title page. / Document formatted into pages; contains 78 pages. / Thesis (M.S.)--University of South Florida, 2003. / Includes bibliographical references. / Text (Electronic thesis) in PDF format. / ABSTRACT: With increasing encroachment on natural communities by anthropogenic activity, it is important to understand the functions of natural ecosystems in an effort to conserve natural areas. A first-hand study of the population dynamics of South Florida Slash Pine (P. elliottii Engelm. var. densa) following a fire event provided insight to its recovery and dispersal following a fire. A natural fire (lightning-induced) occurred in the spring of 2000 at the T. Mabry Carlton, Jr. Reserve, Sarasota County, providing an opportunity to study aspects of slash pine in relation to fire. One objective of my research was to look at dispersal/recruitment conditions and slash pine dynamics in relation to fire. I looked at the varying degrees of tree mortality due to fire at different stands of slash pines. / ABSTRACT: I also looked at the stands in terms of stand composition and spatial arrangement of surviving adults. Finally, I studied how variable seedling establishment and survival was between stands. Few inferences could be drawn between fire and these individual analyses; however, all analyses revealed that at the scale of this study, pine flatwoods are patchy. I also looked at the dispersal of slash pines following a fire event. I modeled my research after Ribbens et al. (1994) and Clark et al. (1998), who took a phenomenological approach to dispersal modeling. This approach involved using distances between adults and seeds/seedlings and fecundity of adults to create dispersal models based on maximum likelihood estimates (MLE). I found that, while I could predict a model within acceptable parameters for most of the stands, more data was needed to predict models that better fit the data. / ABSTRACT: This finding, along with the fact that I recovered no seed data for analysis, suggests factors are contributing to dispersal and recruitment (e.g. cone-crop) that need to be accounted for in the future. / System requirements: World Wide Web browser and PDF reader. / Mode of access: World Wide Web.

South Florida slash pine (Pinus elliottii var. densa) is the southernmost pine species in the United States and the foundation species of the globally endangered pine rockland communities in south Florida. To test if slash pine produces annual growth rings in the Lower Florida Keys, we counted the number of rings on samples collected from the North Big Pine Key site (NBP), which contained a fire scar from a known wildfire and a known date for hurricane-induced tree mortality (2006 or 2007). In addition, a crossdated tree-ring chronology (1871–2009) was developed from living trees and remnant wood found at the site and compared to divisional climate data to determine how the regional climate regime influences radial growth. Our analyses demonstrated that slash pine forms anatomically distinct, annual growth rings with the consistent year-to-year variability necessary for rigorous dendrochronological studies. Response-function and correlation analysis showed that annual growth of slash pine at NBP is primarily influenced by water availability during the growing season. However, no significant correlations were found between tree growth and the Atlantic Multidecadal Oscillation or the El Niño-Southern Oscillation. Our study reveals the potential of producing high-quality dendrochronological data in southern Florida from slash pine, which should prove useful in further studies on fire history and tree phenology and for assessing the projected impacts of impending climate change on the fragile pine rockland community.

Ectomycorrhizas generally improve seedling mineral nutrition and growth, so I hypothesized that decline of the Florida native pine variety Pinus elliottii var. densa Little & Dorman is related to deficiency of appropriate ectomycorrhizal (ECM) fungi in the pine's native flatwoods. At Archbold Biological Station I examined how quickly ECM fungi colonize P. elliottii var. densa seedlings and I compared the effect of local absence versus presence of adult pines on ECM colonization and pine seedling performance. Under controlled greenhouse conditions, I investigated how a wide range of ECM colonization and spread of extraradical mycelium throughout a large volume of relatively infertile, flatwoods soil enhance the mineral nutrition and growth of pine seedlings. In a field bioassay, I transplanted two-month-old pine seedlings to three flatwoods sites with low (4 pines/400 square m), medium (9 pines/400 square m), and high (19 pines/400 square m) adult pine densities. I subsequently excavated seedlings every two weeks for four-and-a-half months and determined their ECM colonization, response to shade, and response to surrounding grass density. Across all sites, pine seedlings in high shade had a higher mean chlorophyll concentration and lower stem dry weight than in full sun. Competition with grass reduced seedling survival and stem dry weight. Initial colonization was rapid and not different among sites, with 5.4 % of roots colonized 15 days after transplant. Pine seedlings had midpoint means of 29.5 %, 18.1 % and 21.3 % ECM root tips in low, medium and high adult pine density sites, respectively, suggesting that pine seedlings establishing in flatwoods encounter sufficient ECM fungi to support their growth, regardless of adult pine density. In a field experiment, I determined in the presence versus absence of adult pines if pine seedlings had higher ECM colonization and consequent improved survival, mineral nutrition, and growth. Within and beyond pine stands, I transplanted seedlings into intact or drilled, hyphae in-growth pipes buried in the ground. I placed autoclaved or fresh ECM root inoculum in two sets of intact pipes, and autoclaved inoculum in drilled pipes into which mycorrhizal hyphae could extend from the surrounding vegetation. Seven-and-a-half months after transplant, ECM hyphae had penetrated the drilled pipes and colonized pine seedlings, but roots from the surrounding vegetation also penetrated pipes. Extraneous roots reduced the survival of seedlings both within and beyond pine stands, but extraneous roots reduced seedling growth only beyond pine stands. Because percentage ECM root tips was higher in the presence (53 %) than in the absence (38.8%) of adult pines, pine stands might benefit the competitive ability of seedlings by increased ECM colonization and possibly by common mycorrhizal networks connecting seedlings to adults. Because beneficial effects of ECM in the field were small, I also examined ECM effects on pine seedlings in a greenhouse experiment. I manipulated ECM fungus colonization and the volume of flatwoods soil to which extraradical mycelium had access. In a small volume of soil (220 mL), fresh ECM root inoculum promoted the mycorrhizal colonization of seedlings versus those receiving autoclaved roots, but seedling growth and uptake of Mg, Ca, and Zn was lower with fresh than with autoclaved root inoculum. Growth and mineral nutrient uptake likely was enhanced by a pulse of nutrients from autoclaved roots, but for inoculated plants may have been reduced because of nutrient retention by saprotrophic microorganisms degrading fresh ECM roots and because of mineral nutrient retention by ECM fungi. Ectomycorrhizal seedlings with extraradical mycelium access to a large soil volume had higher mean chlorophyll concentration than those in a small soil volume. Weekly disturbance of the extraradical mycelium, however, reduced foliar contents of Mn, K, P, N, and Zn by one-third to one-half, and reduced needle dry weight of seedlings by one-third, demonstrating the importance of extraradical mycelium accessing a large volume of soil when it is nutrient-poor. My research demonstrates that ECM fungi are widespread in flatwoods and rapidly colonize pine seedlings. ECM fungus inocula are greater in the presence than in the absence of adult pines, and ECM or seedlings' connections to a common mycorrhizal network improve seedlings' belowground competitive ability. ECM especially enhance seedling mineral nutrition and growth when undisturbed, extraradical mycelium extends throughout a large volume of soil. Populations of Pinus elliottii var. densa might best regenerate in flatwoods if seedlings recruit near adult pines and where there is little competition for light, water, and mineral nutrients.