Prior to its decline and functional extinction due to an invasive blight fungus (Cryphonectria parasitica) in the early 20th century, the American chestnut was a key dominant tree species in most eastern deciduous forests. The infection mechanism, and associated factors affecting rates of infection, must be understood if a hybrid chestnut species is to be reintroduced within native range tree stands.  The focus of our work was on on the blight fungus itself.  Our objectives were to: 1) determine the possibility of hypo-virulent (or less infectious) strains of the fungus being present at our research site, 2) identify factors correlated with infection rates at the site, and 3) examine possible connections between infection and chestnut mortality rates and factors like chestnut type, family, and site location. We sampled each of four types of chestnut (Pure American/Chinese and two hybrids [B3F2 and B3F3]) at the St. George research site where we characterized cankers and tree environment in addition to culturing canker samples under lab conditions.  We did not find evidence of hypo-virulent strains of the chestnut blight at the research site, which could be attributed to hypo-virulent fungus having relatively low success rates due to inhibited sporulation. There was no significant relationship between chestnut species/lineage and infection/mortality rates.  This research could inform the development and success of hybrids used in the reintroduction of American chestnut in the future.

The composition of soil is determined by plants and their organic waste that has been broken down and recycled throughout the ecosystem. This process is controlled by bugs within the soil, called litter fauna. The analysis of litter fauna under the American Chestnut tree species gives details on the effects of that plant on the environment. The American chestnut has been functionally extinct since the introduction of the Chinese Chestnut blight to America in 1910’s. The American Chestnut used to dominate ecosystems and drive industry related to timber and nut harvest. Hybridization of the different American and Chinese Chestnut tree species has changed their morphology over the years in attempts to create a blight resistant hybrid. Scientists are unaware of the effects of the absence of American chestnuts and the emergence of pollinated hybrids on soil type and presence of litter fauna. Litter fauna diversity and population can help distinguish the health of an ecosystem therefore I hypothesized that abundance of individuals of non-Acarina taxa differs among hybrid tree types. Litter was collected under American Chestnut trees, Chinese Chestnut and two of their hybrids. The fauna was extracted using a Berlese funnel and analyzed.  I concluded that there is no functional difference in non-Acarina fauna samples among the hybrids and their pure-bred counterparts. This indicates that the reintroduction of American Chestnuts and their hybrids into the ecosystem will not negatively affect the soil and its litter fauna.