Physiology and leaf characteristics of American chestnut (Castanea dentata (Marsh.) Borkh.) seedlings, saplings, and mature trees in Ohio and Wisconsin /

by Joesting, Heather M.

The restoration of the American chestnut to U.S. forests is currently a subject of much interest. Questions remain about where on the landscape chestnut should be replanted, and the ecophysiological capacity of chestnut at different ontogenetic stages. The goals of the present study were to assess the physiological and leaf characteristics of chestnut and to quantify these characteristics at the seedling, sapling, and mature growth stage. The photosynthetic performance, leaf mass per area, and leaf nitrogen content of chestnut were assessed at sites in Wisconsin and Ohio. Seedlings maximized photosynthesis under high light conditions, a practical result for foresters replanting chestnut. The physiology and leaf characteristics of seedlings and saplings in the understory were similar. Photosynthesis and leaf nitrogen were maximized at the top of the canopy, declining with stand height and light availability. These results will be useful in modeling the carbon dynamics of mature American chestnut forests. Approved: Kim J. Brown Assistant Professor of Environmental and Plant Biology