Ecological Impacts of American-Chinese Chestnut Hybridization on Soil Arthropod Communities and Entomopathogenic Nematodes

Jaq Reed, Abigail Levinson

sreed@unca.edu

BIOLOGY

In the first half of the 20th century, a fungal blight (Cryphonectria parasitica) decimated the American chestnut tree (Castanea dentata) population throughout the Eastern United States. Efforts to create a blight-resistant hybrid using backcross breeding techniques with Chinese chestnut trees (Castanea mollissima) to reintroduce this tree to its native range have shown promising results. In order to understand the ecological impacts of hybridization on belowground communities, we evaluated the abundance and biodiversity of soil arthropods and the presence of entomopathogenic nematodes (EPNs) in stands of chestnut trees with varying levels of American-Chinese hybridization. Arthropods were separated from leaf litter samples using the Berlese funnel method and manually quantified and identified. EPNs collected via soil probe were extracted using the white trap method. No differences were observed in overall arthropod abundance nor EPN presence between chestnut plots. However, the unhybridized American chestnut stand had greater species dominance in comparison to the 75% American chestnut plot as well as a greater number of arachnids, insects, and myriapods than the 94% plot. Our findings suggest that while the general abundances of arthropods are unaffected by hybridization, backcross breeding may impact population composition among groups. Understanding the effects of chestnut hybridization on soil invertebrate biodiversity and abundance will provide context for future projects involving chestnut ecology as well as help identify potential pest species that may threaten the restoration of C. dentata.

May-14-2024