ByTrees provide a significant amount of oxygen necessary for human life. In the Midwest, oak and hickory are large parts of the tree population. Oak and hickory tree populations have declined in the Midwest, but nature groups and organizations work toward improving the production and survival of these native trees. A native plant nursery offers solutions like RPM (root production method) seeds to help in this endeavor.
Why We Need Oak and Hickory Trees
For over 5000 years, oak and hickory dominated the Midwest hardwood forests. They are significant members of Missouri’s forests and are necessary for quality biodiversity. They provide food for a wide variety of wildlife, and besides their acorns and nuts, they attract protein-rich insects necessary for songbird reproduction. Their dense and sturdy branching also offers safe cover and nesting. A mixed herbaceous understory thrives in the vibrant soil under the oak and hickory’s dense canopy.
Qualities of Oaks and Hickories
Both oaks (Quercus spp.) and hickories (Carya spp.) are fire tolerant. Their dominance in Midwest forests testifies to the natural presence of fire in Midwest ecosystems. These species have major ecological value for a wide range of animals, especially moths and butterflies. Various Lepidoptera species rely on oaks as host plants, and birds rely on these insects for food. Here is more information about the specific qualities of oaks and hickories:
Oaks
Oaks are strong and long-lived. There are hundreds of North American oak species due to their tendency to cross-pollinate. Most species are large and deciduous. Each is polygamous with male and female flowers on the same tree.
There are two primary groups of oaks: white and red (or black) oaks. Red oak leaf lobes are pointed and have tiny bristle tips. Since red oak acorns take two years to mature, both small, new, and large, mature acorns appear together. These acorns are generally yellow and more bitter than white oaks.
White oak leaves tend to have wavy lobes without bristle tips. They are a preferred food source by wildlife. Chestnut oaks are a subdivision of white oak. Their leaves have wavy or toothed edges without bristle tips. The chestnut oak survives well on steep, rocky sites where other oaks in its range cannot. Acorns of chestnut oak trees develop independently or in pairs.
Hickories
The other signature tree of Midwest forests is the hickory. These trees comprise a smaller group of about 25 species found in East Asia and North America. Hickories are divided into two major groups: pecan hickories and true hickories.
True hickories have 5–7 leaflets. At the end of each twig is a large egg-shaped bud. Midwest species in this group include pignut, shellbark, shagbark, black, and mockernut. The uncommon sand hickory (C. pallida) is also in this group. It lives only in the Bootheel, on sandy or gravelly soils in upland areas.
Pecan hickories have more than 7 sickle-shaped leaflets. The twig presents an elongated and flattened terminal bud. Missouri’s species in this group include pecan, bitternut, and water hickory. Pecan is the largest species, reaching 130 feet in height. Shagbark, mockernut, bitternut, shellbark, and water hickory may reach 100 feet. The rest are, at most, medium-sized trees. Pignut matures at 80 feet, black hickory at 70 feet, and sand hickory at 50 feet.
Over time, oak and hickory trees altered the Midwest landscape. Their durable hard mast of acorns and nuts sustained wildlife throughout the year, and spreading roots held erosive soils. In fall, a thick blanket of their leaves built both soil fertility and its ability to hold moisture. As those acidic leaves broke down, they altered the soil’s pH balance.
How RPM Helps With Growing Oaks and Hickories
Along with the decline of oaks and hickories in Midwest forests, both genera have dominant tap roots, which make them more difficult to grow and predispose them to high mortality after transplantation. This limitation also suppresses the commercial production of valuable native hardwood species, including oaks, hickories, and pecans.
Growing oaks, hickories, and other native species from seeds helps preserve a forest’s native plant diversity. Plant diversity requires propagation by seed rather than asexual methods, such as vegetative cuttings or tissue culture (cloning). Plants produced by seed are like siblings. They may come from the same parents but have different appearances.
Appropriate provenance (seed source and local ecotypes) also influences sensitive restoration sites. Quality seeds are collected from around the country. The seeds are identified and coded to maintain the seed source of all RPM-produced container plants. The RPM-production method improves plant survival and speeds regeneration. These results are paramount for remediation and restoration sites that focus on oak and hickory. To learn more about oak and hickory growth methods, find a reputable native plant nursery.
Visit a Native Plant Nursery
To restore the oak and hickory population in the Midwest, nature conservation groups can use RPM-produced seeds to speed up mass production. Early seed production allows natural, succession regeneration. Robust, RPM-produced root systems enable successful transplantation on the toughest restoration sites. Contact a native plant nursery for more information on oak and hickory reproduction.
