Researchers at the Duke University Free Air CO2 Enrichment (FACE) research forest in Durham, N.C., are discovering amazing things. FACE is a forest with perforated pipes arranged through it that continuously pump CO2 into it. Among the amazing discoveries as a result of this is a decreased incidence of foliar disease on red maple. Researchers' first impression was that the increased CO2 depressed the growth of the fungus. However, the results of their study showed that not only did the red maple grow more vigorously at an increased 200 ppm CO2, the fungus grew better as well. What they did discover was that the red maple leaves were so efficient at taking in and assimilating CO2, their stomates (or pores in the leaves) were smaller and the fungal hyphae could not fit into the stomates as easily as when grown under lower CO2. The result: more vigorous red maples and fungus but with much less infection. They found that disease incidence was reduced 22 percent, 27 percent and 8 percent over the three years of the study. Although it appears the third year only had 8 percent reduction, this indicates that the presence of the disease is diminishing over time.