Thesis (M.S.)--Virginia Polytechnic Institute and State University, 1993. / Vita. Abstract. Includes bibliographical references (leaves 119-125). Also available via the Internet.

Thesis (Ph. D.)--University of Helsinki. / Includes bibliographical references (p. 86-93).

Thesis (M. For. Sc.)--University of Canterbury, 2006. / Typescript (photocopy). "August 2006." Includes bibliographical references (leaves 101-114). Also available via the World Wide Web.

Forest road building and timber harvesting operations have been recognized as principal causes of forest soil degradation. These activities can result in accelerated soil erosion, excessive scarification, and/or increased soil density, which may adversely affect site productivity. A study of landing areas emphasize the deficiencies in current rehabilitation guidelines Increased soil density on both summer and winter landings was still evident at 30 cm and the soil nutrient quality was poor. Two field tests of a green fallow system on subsoil materials exposed by erosion and landing construction proved successful in building site nutrient capital to acceptable levels. Seedling growth response to green fallow crop establishment in the coastal study verified these findings. A benefit-cost analysis of several forest soil rehabilitation scenarios demonstrated the importance of including secondary and intangible factors. From a pecuniary standpoint, based on primary benefits and costs, rehabilitation was economically feasible only when a low social discount rate (2%) and an optimistic stumpage increase projection (3% per year), were used. A discussion of some secondary and intangible benefits (i.e., harvesting rates, employment, government revenues, erosion control, and industry image) stresses the need for effective forest soil rehabilitation. / Forestry, Faculty of / Graduate

AN ABSTRACT OF THE THESIS OFNicholas Seaton, for the Master of Science degree in Plant Biology, presented on December 4, 2019 at Southern Illinois University Carbondale. TITLE: THE EFFECT OF DEER BROWSE ON ACHYRANTHES JAPONICAMAJOR PROFESSOR: Dr. David GibsonPlants respond in many ways to damage. These responses vary between sites depending on the severity and duration of the incident. One common form of damage in the forest understory is herbivory or browse. White tailed deer (Odocoileus virginianus) have been observed to change the dominant species of forests by selectively browsing palatable species in the understory. These changes in species dominance can lead to unwanted consequences, sometimes resulting in a proliferation of weedy or invasive plants or a reduction in performance and competitive abilities based on morphological traits. Understanding the changes that occur to undesirable species after deer browse can help land managers in their prioritization of sites for land management and understand the driving forces behind a species’ success or failure. Using deer exclosure plots, this study looks at the effects of white-tailed deer on Achyranthes japonica, an herbaceous invasive species in the Ohio River floodplain of Illinois and surrounding states. White tailed deer have been observed to browse A. japonica throughout the invaders range, but little is known about the plant’s response. Deer browse data were collected in the summer of 2018 from May to August. Estimated deer densities among six study sites ranged from 8 to 22 deer per km2. Plants that were browsed during the growing season were morphologically different to those that were not browsed. Browsed plants were 11.5 ± 0.1 cm shorter (F1,218=11.658; p<0.001) on average and produced 0.33 ± 0.09 fewer nodes (F1,216= 4.045; p<0.05). Browsed plants also produced 2.7 ± 0.32 fewer flowering spikes and were similar in length to those of un-browsed plants. These morphological differences showed significant variation between sites. Floristic Quality Indices of the herbaceous plant communities (Ȳ =3.5) ranged from 3.2 to 3.9 among study sites. This study shows that site conditions can impact the response of A. japonica growth as it continues to invade across its current introduced range and that the species is adaptive and grows along-side other similar weedy species such as Microstegium vimineum and Parthenocissus quinquefolia. This study also indicated that deer browse has little to no impact on the growth of Achyranthes japonica.Keywords: Achyranthes japonica, Odocoileus virginianus, herbivory, browse, deer density, site quality

Site preparation is a required silvicultural practice for establishing loblolly pine plantations in the Piedmont physiographic region of the southeastern U.S.; however, relatively little is known about its effect on soil and site factors that influence growth and yield. In this study, the effect of seven different site preparation prescriptions on competing vegetation, tree nutrition, and the spatial distribution of planted seedlings was examined. Three treatments had a soil tillage component and differed with respect to the number of operations employed in removing residual trees and logging slash prior to discing. One treatment involved roller chopping and broadcast burning, one an application of the herbicide glyphosate followed by a broadcast-burn, one involved shearing all raking fogging-debris into windows, and one was no site preparation prior to planting. All treatments were applied to 12 sites in the South Carolina and Georgia Piedmont. After four years in the field, 756 trees within the site preparation treatment areas were randomly selected for analysis of foliar nutrients, soil nutrients, and competing vegetation. Herbaceous, woody shrub, and hardwood competition levels were not significantly different among site preparation treatment areas after four years. However, hardwood competition levels had increased at a faster rate during the last two growing seasons on chopped and disced areas than on the other areas. Hardwood competition became the predominant factor limiting pine basal diameter when 83% of the total basal area was in hardwoods or hardwood basal area levels exceeded 3.5 m²ha⁻¹. Potassium was identified as the most limiting nutrient 38% of the time, compared to 28% for phosphorus, 14 % for nitrogen, 7% for calcium, aiid 13% for magnesium. A significant linear relationship between soil and foliar nutrients confirmed these results. No treatment effect on nutrient deficiencies was evident. Foliar nutrient critical levels were derived using the Diagnosis and Recommendation Integrated System (DRIS) and were the same as those reported in the literature for nitrogen, phosphorous, and magnesium while potassium and calcium critical levels were determined to be twice as high as those reported (0.52% and 0.19%, respectively). The spatial distribution of seedlings at planting and after 2 years was determined. Spatial patterns varied from uniform to random as the degree of logging slash removal decreased. After two years, the spatial distribution shifted toward random and clustered. The degree of change was similar in all but the herbicide burn and untreated areas, which exhibited the greatest change and whose mortality tended to be clustered. / Ph. D.

Knowledge of ecological site characteristics and tree growth on different sites is fundamental for silvicultural decisionmaking and planning. With biogeoclimatic ecosystem classification in place in British Columbia, silvicultural management has been given an ecological foundation; however, relationships between growth and site quality have not yet been fully investigated. The purpose of this study was to determine how site conditions within the SBS zone affect the height growth of lodgepole pine (Pl) and interior spruce (Sx).

M.Sc. (Botany) / Global efforts to protect the world’s forests from unsustainable and inequitable exploitation have been undermined in recent years by rampant illegal logging in many timber-producing countries. A prerequisite for efficient control and seizure of illegally harvested forest product is a rapid, accurate and tamper proof method of species identification. DNA barcoding is one such a tool, relatively simple to apply. It is acknowledged to bring about accuracy and efficiency in species identification. In this study a DNA barcode reference library for traded and protected tree species of southern Africa was developed comprising of 81 species and 48 genera. Four primary analyses were conducted to assess the suitability of the core barcodes as a species identification tool using the R package Spider 1.2-0. Lastly, to evaluate this identification tool, query specimens independently sampled at a Mozambican logging concession were identified using DNA barcoding techniques. The nearest neighbour (k-NN) and best close match (BCM) distance based parameter yielded 90% and 85% identification success rate using the core plant barcodes respectively. DNA barcoding identification of query specimens maintained a constant 83% accuracy over the single marker dataset and the combined dataset. This database can serve as a backbone to a control mechanism based on DNA techniques for species identification and also advance the ability of relevant authorities to rapidly identify species of timber at entry and exit points between countries with simple, fast, and accurate DNA techniques.

Site preparation treatments are often used prior to the planting of clearcut forest lands to improve planter access and to increase the number and quality of planting spots. Most mechanical site preparation treatments alter the configuration and material composition of surface soil materials, and can have marked effects on soil properties important to seedling survival and growth. Effects of some of these treatments on soil moisture, soil temperature, rates of nitrogen mineralization, and the establishment of Picea glauca x engelmannii seedlings were examined on fresh, moist, and wet sites in the moist cold subzone of the Sub-boreal Spruce Zone in west-central British Columbia. Four types of microsite alteration were investigated: forest floor removal (spot scalping), soil mounds over inverted sections of forest floor (inverted mounds), mineral soil mounds over a mineral soil surface, and inversion of the forest floor and mineral soil in place. Soil temperature was monitored continuously and soil moisture weekly at the 10-cm depth in 16 combinations of site and microsite treatment during two growing seasons. The response of seedling height and diameter growth was monitored for three growing seasons. Effects of altering soil temperatures through mechanical treatments on rates of nitrogen mineralization were examined by incubating a standard soil material in a range of microsites created by six combinations of site and mechanical treatment. Effects of substrate quality and soil temperature on rates of nitrogen mineralization were examined in paired mounded and untreated spots in fresh, moist, and wet sites. In all sites, early growing season soil temperatures in the seedling rooting zone were substantially warmer in inverted mounds than in other treatments. Spot scalping increased temperatures slightly relative to controls in the fresh site, but had little or no warming effect on moist and wet sites. Inverted mounds became substantially drier than other treatments during periods of low rainfall, particularly in the fresh site. After three growing seasons, seedling height growth was greatest in inverted mounds, irrespective of site. Amounts of nitrogen mineralized in a standard soil material during incubation for 77 days in the field were significantly greater for samples placed in inverted mounds than for those placed in other microsite treatments. There was a significant positive correlation between amounts of nitrogen mineralized during field incubations and degree hour sums calculated for associated microsite treatments and sites. Both substrate quality and soil thermal regime affected rates of N mineralization in samples from paired mounded and untreated spots, and an interaction was observed between the two factors. / Graduation date: 1991

Thesis (M.S.) in Ecology and Environmental Science--University of Maine, 2009. / Includes vita. Includes bibliographical references (leaves 78-87).