Abstract: Thus far, little scientific research has considered other species associated with the community of the American chestnut and the chestnut blight fungus.  However, community ecology may be important in understanding the dynamics of chestnut blight infection, and for predicting the outcome for individual chestnut sprouts.  I tested if lichen growing on chestnut sprouts inhibits vegetative growth or reproduction of the chestnut blight fungus.  In the field portion of this study I sampled chestnut sprouts at Mountain Lake Biological Station (MLBS) near Pembroke, VA for lichen coverage using a line transect method and found that healthy trees had significantly more lichen than diseased trees of the same age.  Also, individual transects in which no Cryphonectria pycnidia were present had significantly more lichen than transects where pycnidia were present, suggesting the effect of lichens was on a local scale.  In a laboratory experiment, fungal hyphae growth was inhibited by chemicals extracted from the two species of lichen growing on the chestnuts sampled.  However, conidia germination was increased by the presence of these extracts.  The demonstrated inhibition of hyphae growth on a local scale and the difference in lichen coverage between healthy and diseased sprouts of the same age may be evidence that lichen increase the lifespan of chestnut sprouts by prolonging the time before they become infected by the blight fungus or by slowing the course of the disease.