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The concept of place is extremely important within today's contemporary society. As a result of hyper mobility, many people do not take the time to notice and understand the spaces surrounding them. A sense of place is subtle and fragile, yet can exist in the most humble of environments. In Appalachian, there are countless structures that dot the mountainous landscape symbolizing the sense of place in southwestern Virginia. The Virginia pole barn is important for the sense of place because of its direct tie to the land. Many of these structures were built from the indigenous American chestnut tree and crafted using traditional building techniques. These structures are an important contribution to the vernacular of the Appalachian region, and much of this is due to the material presence of these structures as they give balance and counterpoint to the ridges and valleys. Secondary research focused on theories about the creation of place, the spirit or character of a specific place, the role of symbols in these creations, and the importance of the American chestnut as a material. Primary research concentrated on the people who interact with these pole barns on a regular basis, the structures themselves, and the prevailing landscapes. / Master of Science

Results of inoculations of grafts, seedlings, excised stems, and intact trees of large, surviving American chestnut indicated that some have heritable blight resistance. Some degree of resistance in American chestnut possibly would assist spread of hypovirulence (H) factors. The pathogenicity of the H isolate but not the V (virulent) isolate appeared to influence the size and sporulating characteristics of biocontrolled H+V cankers. The histopathology of canker development on blight-resistant Chinese and blight-resistant and blight-susceptible American chestnut was examined after inoculation with V and H E-parasitica. Rapid formation and continual growth of mycelial fans distinguished chestnut blight cankers incited by V E-parasitica from those incited by H E-parasitica, and distinguished cankers on susceptible chestnut from cankers on resistant chestnut. Differences among such cankers in wound periderm and other pathological alterations of bark and wood anatomy probably were results of differences in rates of fan formation and growth. Wound periderm formation began at the deepest point of a wound or canker and progressed outward to the bark surface. Superficial cankers arose in resistant trees or with hypovirulent fungus when slow-forming mycelial fans expanded through areas where wound periderm had not formed. Rapid epidemics of chestnut blight occur in recently clearcut areas but not in areas with large trees of species other than American chestnut, most probably because chestnut sprouts released after cutting become larger than they do when overtopped by large forest trees. The size of chestnut sprouts appeared to influence the rate of blight progress by setting a maximum limit on canker size and thus canker sporulation. It may be possible to foster spread of H factors in the Appalachians if blight epidemics in clearcuts can be prolonged. This might be done by restricting inoculum production. Cutting and removing some blighted sprouts, cutting some large unblighted sprouts, or increasing blight resistance in the chestnut population are three potential means of restricting inoculum production. / Ph. D.

Phytophthora cinnamomi is a soil-borne oomycete pathogen causing root rot in susceptible host species. P. cinnamomi is thought to have originated in Southeast Asia, but has since been introduced to many regions around the world, where it causes dramatic declines in many forest tree species. In the eastern US, the primary susceptible tree species of concern are American chestnut (Castanea dentata), white oak (Quercus alba), and shortleaf pine (Pinus echinata). American chestnut, functionally eliminated in the early 1900s by the rapidly acting chestnut blight (Cryphonectria parasitica), has been the subject of decades-long breeding efforts aimed at improving chestnut resistance to chestnut blight. To improve chestnut restoration success, and restoration of other susceptible species, the distribution patterns of P. cinnamomi on a landscape scale must be better understood. This project was initiated to develop an improved method for detecting P. cinnamomi to permit high-throughput screening of forest soils, and to implement the improved detection approach in characterizing the distribution patterns of P. cinnamomi in developing soils on reclaimed surface mines in eastern Kentucky, as well as mature forest soils within an undisturbed watershed in a reference-quality eastern Kentucky forest. We developed an improved detection method using a molecular DNA-amplification approach (PCR), which demonstrated similar sensitivity to traditional culture-based methods, but required less time and space than traditional methods. We used this detection approach to screen soils from a chronosequence of reclaimed surface mines (reclaimed at different points in time) to evaluate whether reclaimed surface mined sites become favorable for P. cinnamomi colonization over time. Our analysis detected P. cinnamomi at the two older sites (reclaimed in 1997 and 2003), but we did not detect P. cinnamomi at the two newer sites sampled (reclaimed in 2005 and 2007). These results suggest that surface mined sites become favorable for P. cinnamomi colonization over time, and should not be considered permanently “Phytophthora-free.” We also collected ~200 samples from a watershed in UK’s Robinson Forest, from plots representing a gradient of topographic position, slope, and aspect. This survey indicated that P. cinnamomi distribution in forests is complex and can be difficult to predict; however, P. cinnamomi was detected in both drier upslope sites and in moister drainage sites.

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