Efforts are underway to restore the American chestnut, Castanea dentata (Marsh.) Borkh, to its original range within the United States. The American Chestnut Foundation has traditionally focused on introducing blight resistance of the Chinese chestnut, C. mollissima Blume, into their breeding stock. Now, however, they are encountering problems with a root rot caused by Phytophthora cinnamomi Rands, and the threat of a potential disease caused by Phytophthora ramorum Werres, De Cock, and Man in?t Venld. In order for the Foundation to breed for resistance against the effects of these pathogens, much more needs to be discovered regarding their interactions within Castanea. This thesis is part of the effort to understand these interactions. The first chapter provides a literature review of interactions for two Phytophthora species and Castanea spp. The second chapter presents experiments investigating the mode of inheritance and number of loci controlling resistance to each of these Phytophthora species. Initial experimentation appears to suggest that resistance to P. cinnamomi may be controlled by a single dominant gene in chestnut, but conclusive evidence from subsequent experiments was not found; possible causes are discussed. A series of screening assays based on leaf disk assays using P. ramorum also failed to provide conclusive evidence that a single locus controls the degree of response, but statistically significant differences were noted among seedlots in each trial, suggesting some level of genetic control. The third chapter presents a genetic linkage map developed from amplified fragment length polymorphic (AFLP) markers for the F1 parent in a backcross family ((C. mollissima ?Mahogany? x C. dentata ?RCF1? = ?KY115?) x C. dentata ?WB348?). This purpose of this map is to correlate future resistance segregation patterns from controlled P. cinnamomi inoculation trials with specific marker loci. This would provide a foundation for future genetic research regarding the number of loci controlling resistance to root rot caused by P. cinnamomi and its relationship with other traits of interest in chestnuts.

Since the 1970s multiple research efforts around the world have focused on identifying potential environmental, economic, and social impacts of development. It is well understood that local project assessment approaches fail to identify, or worse quantify, indirect or cumulative effects, when they do not provide an appropriate baseline framework to understand the local and the regional environment as a connected entity. A conceptual approach based on several environmental assessment and spatial analysis tools suggests that we need to consider multi-scale methods that can help describe the different processes that occur within a region. This would help project managers and researchers to better evaluate ongoing regional policies by retrieving a wide characterization of the application and impacts of policies within the whole geographical spectrum. Within each policy assessment, these methods could evolve into a framework for environmental management practices at both local and regional scales that could be updated with new information through time. We analyze two regional policy case studies: poverty targeting in Sri Lanka, and payments for ecosystem services in Costa Rica.

Successful restoration of a wetland requires that wetland vegetation be established at the site. Unfortunately, the hydrologic regime of restored wetlands is frequently incompatible with these communities and the vegetation can not survive. This is sometimes a result of improper hydrologic design, but in many cases it is due to a lack of understanding of the hydrology required by these plant communities. The objective of this study was to provide quantitative data describing the long-term (40 yr) hydrology associated with the Pond Pine Woodland (PPW), Nonriverine Swamp Forest (NRSF), High Pocosin (HP), and Bay Forest (BF) plant communities found in three undisturbed Carolina Bays on the North Carolina Coastal Plain. This objective was achieved by simulating water table depths in the various plant communities in the bays over a 40 yr period with calibrated DRAINMOD hydrologic models. The hydrology of the PPW community differed significantly from that of the NRSF, HP, and BF communities in that water tables were deeper in the soil profile, water was ponded on the surface less often and for shorter durations, and the water table dropped to mineral soil horizons more frequently for extended periods of time. Further, the PPW received an average of 15% of its water input from groundwater inflow, whereas the other communities did not exhibit groundwater inflow. The source of the groundwater inflow is not known but it is believed to be a local phenomenon. The water could enter the bays either laterally from adjacent uplands or vertically from confined aquifers below. A confined artesian aquifer below one of the bays was likely the source of inflow for that bay. The hydrology of the NRSF, HP, and BF communities were very similar. The water table in the NRSF and HP occasionally dropped to mineral soil horizons, which may provide them with additional fertility relative to BF. The results of this study will enable wetland restoration engineers to better approximate the natural hydrology of these plant communities at a restoration site, thereby improving vegetation establishment success.

Several studies have examined the theoretical aspects of determining the optimal carbon rotation. This paper explores the tradeoff between timber and net carbon sequestration in managing representative forest management types in North Carolina. Under conservative assumptions regarding the social benefits of carbon storage, optimal rotation periods are extended depending on the forest type, carbon price, interest rate, and emission penalty under consideration. Analysis shows when carbon price is low the extension of the joint timber-carbon rotation are similar among DOE, CCX, and VCS protocols; when carbon price is high, the joint rotation extends longer under DOE protocol than the other two protocols, especially in the lowland hardwood forest type. Results suggest that such joint strategies could be financially attractive. Sensitivity analysis is used to examine the effects of changes in financial parameters on landowner returns and optimal management. Under most assumptions, our findings indicate that including carbon sequestration in forest management increases returns but leads to only marginal changes in rotation length.

The goal of this research study was to contribute to a better understanding of the challenges and opportunities of developing a woody biomass industry that includes non-industrial private forest (NIPF) landowners. Surveys were administered to 475 forest landowners before and after a forestry extension education program on emerging woody biomass markets in ten counties across North Carolina. We predicted that landowners would have low knowledge levels of woody biomass but, as a result of participating in the training, would increase knowledge, have more positive attitudes, and develop aspirations to harvest woody biomass on their land. Results, based on 395 returned surveys, confirmed these hypotheses, thus strengthening the perception of the importance of woody biomass educational programs as a component of renewable energy adoption plans. However, while the majority of landowners reported that the information gained was beneficial, we found that landowners would like more specific information before committing to participate in emerging woody biomass markets. Outreach to minority and traditionally underserved landowners also requires considerable development. If Extension professionals do not make a conscious effort to reach out to these populations they will be effectively excluded from this woody biomass market opportunity. These findings will assist Extension agents and other adult educators, policy makers, and energy or timber industry professionals to make informed decisions when developing policies and programs concentrated on woody biomass harvesting for energy.

Environmental site-specific constraints on shoot, branch, and leaf area growth and phenology were investigated during the third and fourth growing seasons in two-year-old radiata pine plantations established under a factorial combination of soil preparation, fertilization, and weed control at three contrasting textural and climatic soil-site conditions in the Central Valley of Chile. During October 2002 and June 2005, biweekly measurements of foliage accretion, branch, and stem growth were obtained together with periodical evaluations of foliage senescence. At each site, tree growth, aboveground biomass, belowground biomass, total biomass, aboveground:belowground biomass ratio, and leaf area index increased mainly by weed control (WC). The large gradient of tree growth and biomass accumulation among sites, and within sites varying in response to WC, was mainly attributed to large differences in soil water availability and possibly atmospheric water demand differences within sites. A linear relationship was established between LAI and stand growth across sites. The slope of the relationship (stemwood growth efficiency, GE) varied from 2.9 m3ha-1year-1 to 6.8 m3ha-1year-1 per unit of leaf area, with lower growth efficiencies found on sites with the greater water constraints. Phenology of growth was little affected by site or silvicultural treatments. Seasonal differences in the patterns of growth were mainly observed among sites for diameter, with longer growing seasons at sites with lower water limitations. In contrast, strong site and silvicultural treatments effects were observed on tree morphology. Trees where water limitations were more severe exhibited fewer and shorter flushes of height growth. The negative effects of soil water limitations, were at least partially ameliorated by silvicultural treatments that had been applied three years previously. Resource availability constraints during the mid to late growing season affected diameter growth more than height growth. Phenology of fascicle elongation indicated that sites with water and nutritional constraints ended fascicle elongation earlier during a growing season. Phenology of fascicle senescence indicated that maximum needlefall occurred during the summer and autumn seasons. No differences in silvicultural treatments were observed in foliage accretion or senescence patterns. Foliage longevity increased for sites with water and nutrient limitations.

Fungi play an important role in recycling woody debris in forest ecosystems. The dynamics of fungal decay of woody debris are important factors in creating animal habitat and soil organic matter as well as causing economic losses in the commercial utilization of timber resources. Polypore fungi account for approximately 70% of the fungi capable of decaying wood. On September 6,1996 winds from Hurricane Fran downed trees throughout the Piedmont of North Carolina and provided abundant substrate for polypore development. The objectives of this research were to: 1)Survey two forested tracts, totaling 115 hectares, for the occurrence of polypore fungi; 2) Record any new fungi or host-fungi associations for North Carolina; 3) Develop a key, based on macroscopic features, to these polypores for use by non-experts. A 100% cruise of Schenck Forest and an adjacent tract of land in Wake County, North Carolina was completed. Fifty-six polypore species representing 37 genera in five families were observed. Twenty-four taxa of woody plants were recorded as substrates. Six of these fungi are new reports for North Carolina. Fourteen of the host-fungi associations are new reports for the United States. A key and individual species descriptions are presented.

Soil degradation, persistent drought, and a continuous decline in peanut market prices combine to put Senegalese farmers in a difficult position. To avoid a complete system collapse, many have called for a paradigm shift from production to resource conservation and regeneration with the participation of rural populations (Advisory Committee on the Sahel et al., 1986; Cook, 1989; Rodale Institute, 1989; Chemonics International Inc., 2000; Franzel and Scherr, 2002). Cashew (Anacardium occidentale) alley-cropping represents an ideal opportunity for restoring soils while maintaining productivity, but farmers take time to adopt such new technologies. Some farmers are naturally more receptive to these new ideas than others (?early adopters?), and some farmers are more likely to encourage others to try new ideas (?effective advisors?). This thesis defines and identifies observable characteristics of these two types of farmers, arguing that they are the best extension multipliers and therefore good points of contact for extension agents to effect quick diffusion of the innovation through the village. This thesis contributes to the literature first, by considering time of adoption using quantitative methods that have typically been applied only to the decision whether or not to adopt at a particular point in time, and second, by incorporating into the model spatial and social relationships that are often ignored in adoption literature. The study was conducted in two small farming villages in the Sine-Saloum region of Senegal?Mamouda and Simong. I lived with a family in Simong for nine months and learned about the local culture and environment (June 2003-February 2004), and returned for three months of interviews and spatial data collection (February-April 2005). Qualitative and spatial data were analyzed, and quantitative data were used to estimate survival and probit regression models for time until cashew adoption, and OLS models for advisor effectiveness in cashew promotion. It was found that an effective extension multiplier will have assets and land with which to absorb any possible costs of failure, will have fields that are highly visible and centrally located in an area appropriate for cashew production, will be in the elder age class (more than 60 years old), and will be socially well-placed as an advisor to many and an advisee to none. Understanding the characteristics of early adopters and effective advisors will allow extension agents to quickly identify the few farmers who are most likely to adopt on the advice of an outsider and without the prior sanction of their peers, and who will then demonstrate and extend the innovation with little outside assistance. Focusing efforts on these key players should increase the effectiveness of the agent?s time spent in the village, and after a successful training and trial, the new technology should then spread with little further intervention through farmer to farmer contacts (Advisory Committee on the Sahel et al., 1986; Bunch, 1982; Rodale Institute, 1989). This should result in a quicker and more effective impact of extension on the welfare of these poor farming communities.

<p>MORISETTE, JEFFREY THOMAS. Using Generalized Linear Models to Enhance Satellite Based Land Cover Change Detection. (Under the direction of Siamak Khorram.)<p>A popular satellite based land cover change detection technique is to compare the spectral information for each pixel, from two images acquired at different dates. For each pixel, if there is a big enough difference between the reflectance values from the two images, the area represented by that pixel is considered to have changed. The change detection methods are different in how they determine a "big enough difference". The analyst is left to choose which function of the reflectance values to use and where to set the "change" threshold. These choices are often subjective and affect the accuracy of the change detection. In this dissertation we describe and defend the thesis that Generalized Linear Models can be used to enhance satellite based land cover change detection. This is done by first presenting some background on satellite based change detection and then describing how the Generalized Linear Models relate to existing satellite based change detection algorithms. This is followed by an example change detection, which utilizes Generalized Linear Models. The example uses subset images from Landsat Thematic Mapper Data. The data are from 1988 and 1994. For each time period there are overlapping subset images for an area over Raleigh, North Carolina and two overlapping subset images for an area over a coastal region of North Carolina. In each region we collect a sample at 260 ground locations. For each location, land cover changes are determined from high-resolution air photo reference data. This is coupled with the satellite radiance values for the corresponding area. Generalized Linear Models are then used to regress the binary response of change/no-change (as determined from the air photos) on the radiance values extracted from the satellite imagery. In doing so, the models help determine the most appropriate function of the reflectance values to use for predicting change. For the data in this study, the GLMs indicated a combination of radiance values to be more accurate than a single band or single index. Also, the models indicate that different combinations of radiance values should be used for the different study areas. Next, the models are used to produce "accuracy assessment curves". These curves show the relationship between the location of the "change threshold" and the accuracy of the associated change classification. These curves can be used to compare two models across all possible change thresholds. Finally, the models are incorporated into the satellite imagery to produce "probability of change" (POC) images and "variability" images. In the POC image the pixels contain continuous values ranging from zero to one, representing the probability that the area has changed. The pixels in the variability image contain values corresponding to the variability of the estimated POC. Results indicate that incorporating Generalized Linear Models into satellite based land cover change detection yields a more quantitative change detection procedure and more informative change detection products. There are three ways to utilize the models. First GLMs can help select the most significant set of explanatory variables to use in the change detection. Next, the output from the GLMs can be used to produce what we will refer to as "accuracy assessment curves". These curves show the relationship between the threshold value used to classify change areas and the accuracy of this classification. The third use is through incorporate the modeling into the image data to produce continuous "probability of change" images in which the pixel values range from zero to one. These values represent the probability that the area represented by that pixel has changed.<P>

<p>HALL, KAREN RENAE. COMPUTERIZED DENDROLOGY: The identification and natural history of the pine trees of southeastern North America. (Under the direction of Richard R. Braham.) A computer database of the pines of southeastern North America was developed using hyper-text markup language. This interactive program allows users to learn about bark, buds, leaves, reproductive structures, geographic range, climate, and natural history of pines. Audio files pronounce the scientific and vernacular names of trees. A search engine allows comparison of textual and graphic information of different characteristics.<P>