Cryphonectria parasitica is a microscopic fungus that attacks primarily tree species of the genus Castanea (chestnut) by penetrating their injured bark and colonizing the inner bark and cambium, disrupting nutrient and water flow and causing chestnut blight. Cr. parasitica severely impacts American chestnut (C. dentata) and European chestnut (C. sativa) causing major ecological damage and economic loss. Data from 2010 reveals that this pathogen partially or entirely defoliated and killed 40 % of Georgia's chestnut forests. In this study, we used generalized additive models (GAMs) to test whether environmental factors influence the severity of blight-induced defoliation of chestnut trees across Georgia. Mean annual precipitation emerged as the most impactful factor, followed in order of significance by slope, understory cover, mean annual temperature, and aspect. Our research contributes to a broader research agenda aimed at laying the groundwork for more informed conservation efforts. Keywords: Chestnut; Caucasus; Chestnut blight; Climate; Modeling; Defoliation; Severity
