Last October I spent a magically beautiful, but painfully upsetting, day in Fontenelle Forest near Omaha. On a floodplain in a loop of the Missouri River stood a climax forest of magnificent tall oaks, shagbark hickories, and lindens at the peak of their fall colors. In the last warm weather of autumn, the forest pools were teeming with America's loveliest water bird, the wood duck, while frogs basked on logs and deer browsed through the forest. From an overlook on a ridge rising out of the floodplain, the great river shone through the mist in the distance.
The silence, and the scene's peaceful magic, let me imagine that nothing had changed for thousands of years. I could easily forget that Fontenelle Forest is just a 1,300-acre reserve left from the Missouri's formerly extensive floodplain forests, most of which have long since been destroyed in the cause of human progress. Around the reserve stretch suburbs and farmlands, an artificial landscape against which Fontenelle Forest stands in contrast as if stamped out by a cookie cutter.
For the survival of the forest today, we can thank the Fontenelle Forest Association, a private nonprofit organization founded with the stated goal of preserving the forest in its natural state. Without any help from tax dollars, Omaha citizens raise money from private sources and serve without pay as directors. The association's rule 1 for visitors to the forest reads, "All plant and animal life is strictly protected"; rule 2, "No hunting, fishing, or weapons." The underlying philosophy for operating the reserve is one of no management, no interference by humans.
I wish I could report that these efforts were safeguarding the future of this wonderful ecosystem. They were not, and that was the painfully upsetting part of my visit. Closer examination of the forest showed that all the oaks, hickories, and lindens were mature trees; I saw no seedlings. On the forest floor were few acorns and hickory nuts needed for the forest's continued regeneration. The sight felt like visiting an apparently thriving country and suddenly realizing that it was inhabited mainly by old people, and that most of the infants and children had died. While I expected to find dense thickets under the scattered crowns of the great trees, the forest understory was actually so open that I could walk through most of it. Most of the saplings were species like ironwood and hackberry, which are pioneers in disturbed environments and which reproduce themselves by windblown seeds or tiny fruits rather than by big nuts. Ecologists would describe the forest as in reverse succession: not the usual pattern of shrubs yielding with time to saplings yielding in turn to tall old trees, but the reverse. What's going wrong with Fontenelle Forest?
A significant part of the answer involves the deer I saw browsing in the forest. In the Omaha area, as throughout much of the Midwest and East, deer are becoming abundant, thanks to our unintended help. We provide the equivalent of supermarket conditions for deer by breaking the landscape into the habitat mosaics that they prefer, planting crops on which they feed, and eliminating the big carnivores that used to keep down their numbers. The deer contribute to preventing Fontenelle Forest's regeneration by eating acorns and nuts, from which new oaks and hickories would sprout, and by browsing shrubs and low saplings. Deer thereby indirectly affect most of Fontenelle's other plant and animal species as well. Understory bird species that would normally breed or winter at Fontenelle are declining there, as are butterflies, which depend on understory plants for food, and wintering woodpeckers and jays, which feed on fallen nuts. The forest understory is changing a nursery for oak and hickory seedlings into a haven for "deer-proof" plants, such as poisonous snakeroot and stinging nettles.
This tragic situation arose out of the Fontenelle Forest Association's laudable policy of noninterference. …