American chestnut, once a mighty dominant tree of eastern North American forests, has fallen a victim of an introduced fungus, chestnut blight disease--and large trees have been reduced to shrub size. You can watch four unsuccessful attempts of the same tree to recover. The fungus lets the tree attain a certain magnitude before it kills. Each subsequent attempt yields less and less growth, as the plant's potential is depleted. The largest chestnut trunk in this photo is by no means the original coloss that fell down first, probably about a hundred years ago. Yet its root system keeps sending out more and more generations of stems. The current generation is the shrub on the left of the large dead trunk.