Regenerating Oaks in Missouri's Bottomlands
In ancient Greek, Roman and Celtic mythologies, oak trees symbolized strength and virility. Oak groves were sacred places to Celtic and Druid cultures of the British Isles. Oak has long symbolized strength, endurance, military prowess, victory, royalty and fertility.
In addition to their symbolic, cultural and aesthetic values, oaks have also proven useful throughout history. Military and merchant sailing ships were built of oak. Because of its strength and endurance, oak wood was favored for building homes, crafting furniture and manufacturing household items. Charcoal produced from oak wood fueled the iron and glass industries in the 18th and 19th centuries. Oak bark, with its high tannin content, was important in the leather tanning process. Acorns have also provided nourishment for humans around the world.
Missouri once had an estimated 5 million acres of wetlands, much of which were bottomland forests that included some oak. Today, less than 15 percent of those historical wetlands remain in the state. Many landowners and public land managers are interested in restoring oak trees on the bottomlands of Missouri's rivers for wildlife and timber purposes. However, creating forests from acorns is not as easy as Ralph Waldo Emerson makes it sound.
Young oaks growing in bottomlands face serious challenges. Seedlings must compete with the lush growth of other plants. Because oak seedlings grow slowly, they are often shaded out by Johnson grass, Reed canary grass, giant ragweed, marestail, cottonwood, willow and other fast growing species that are better adapted to colonizing bare, open bottomland fields.
In bottomlands, animal damage often limits oak regeneration. Squirrels and other small rodents eat acorns planted in forests or fields, and many wildlife species eat planted nursery seedlings. White-tailed deer can slow tree development for years by repeatedly browsing on the twigs and buds of seedlings. If they eat the terminal or uppermost bud they can prevent a tree from growing taller. In winter, cottontail rabbits may completely sever the stems of small oaks, or chew through the bark and cambium of larger seedlings, killing them. Mice, voles and other small mammals also damage tree seedlings.
It's important to properly match the species of oak with the soil and the flooding tendency of the planting site. Several oak species are native to Missouri bottomlands, but their ability to tolerate flooding varies. Bur oak, swamp white oak, Nuttall oak, overcup oak, water oak and willow oak do well in frequently flooded areas.