Poster

         Ecology

Environmental niche and demographic modeling of American chestnut near its southwestern range limit

Presenting Author
Robert Laport
Description
The unintentional introduction and rapid spread of chestnut blight (caused by Cryphonectria parasitica (Murr.) Barr) in the early 20th century resulted in the demise of American chestnut (Castanea dentata (Marsh.) Borkh.; Fagaceae) as a major component of forest canopies resulting in negative impacts on eastern forest communities. Research efforts over the last century have documented the persistence of occasional remnant individuals throughout much of the species' historic range, providing the basis for ongoing breeding of blight-resistant trees and restoration efforts. Here we use environmental niche modeling to evaluate the climatic suitability and reintroduction potential near the southwestern range limit. We also use stage-structured matrix projection models to investigate the potential demographic future of C. dentata in a relatively understudied portion of the historical range based on observations of American chestnut in these areas over the last several decades. We found climatically suitable upland forest habitat with high canopy cover occurs throughout much of the southwestern portion of the historical range, but populations of American chestnut in these areas are predicted to drastically decline over the coming decades. These results suggest the southwestern extent of American chestnut's historical distribution should be incorporated into evaluations for future reintroduction, and emphasize the need for efforts to locate, conserve, and introduce genetic material from individuals with locally adapted genotypes into active restoration programs.