Beech bark disease: a studty on the effects of disease and demise of the American beech (Fagus grandifolia) in the Wells plot

Abstract

The American beech (Fagus grandifolia) has experienced major decline due to the presence of beech bark disease (BBD) in the United States since 1929. We studied how the radial size and growth related to the disease of the beech tree and its severity. We also looked at the spatial aspect of the disease and if this had any correlation with how the BBD was dispersed throughout the forest. To do this we used the Wells plot near Pellston, MI to conduct our study since there have been recordings of the diameter at breast height (DBH) of all trees in a one-hectare piece of land since 1927. We recorded DBH and severity of the disease on all 287 trees within the Wells plot and ran statistical analysis to see how radial growth was related to severity of disease and how distance effected the spread of the disease. We collected data that suggested there was correlation with the size and growth of the trees and the severity of the infection. We also collected data that suggested that the larger the DBH the more likely that there will be clustering of the disease. Beech may survive for long periods of infection from beech bark disease. However, our results demonstrate that the radial growth is reduced as the infection enters an area of uninfected beech trees.