Green Horizons

On Sept. 9, 2005, a Tree Farm® in eastern Wayne County, Mo., was host to a progressive forest management practice called early release. This practice consists of the aerial application of a forestry herbicide called Arsenal® AC with a low flying and slow moving helicopter. While not innovative—this practice has been used extensively in the southern U.S. and elsewhere— aerial release applications have not been seen in the Ozarks region of Missouri since the 1960s.

The project, coordinated by Clearwater Forest Consultants (CFC) of Piedmont, Mo., is designed to restore pine to a portion of the landscape while realizing a return on investment. Arsenal® AC was applied to pine plantations that have completed two or three growing seasons as part of the restoration project.

For the owners of this Tree Farm®, managing pine is a solid objective. At one time, shortleaf pine was the dominant tree in their forest. In addition, the selected sites are better suited for pine than for oak and other hardwood species. The virgin pine forest types were maintained by low intensity ground fires that passed through forests every 3-15 years. Early 1900’s logging and an increase in severe fires, followed by a period of fire suppression, drastically changed the landscape and forest vegetation types. Today there are not enough naturally occurring pine trees to serve as a seed source. Also, bringing back fire will not restore shortleaf pine. Prescribed fire is expensive, requires skill and is restricted to small windows of opportunity. A better way to bring back the pine forest is to establish plantations.

Helicopter beginning a run at the edge of the tree line

When a pine tree is planted, it faces an uphill battle because it must spend time and resources establishing its root system before it can even begin to compete. From a pine tree’s perspective, survival depends on capturing more of those resources than the grasses, vines, briars, and hardwood stump sprouts surrounding it. Resprouts from nearby hardwood stumps quickly overtop the pine seedlings, eventually shading them out.

An early release spraying with Arsenal® should eliminate competing hardwood, grass, and vine competition, but will not harm the planted pine trees. Arsenal® works by entering a plant through the leaf. Pine trees are not harmed by the herbicide because they metabolize the herbicide faster than broadleaved plants and work it out of their systems before the chemical has a chance to kill them. In addition, the shape of the pine leaf (needle) and its waxy outer layers naturally reduce the amount of chemical encountered by the tree. Following application, the herbicide has killed most of the hardwood and grass competition by the following spring, giving the planted pine seedlings a head start in the race for growing space.

Another benefit of herbicides like Arsenal® is that they can actually enhance wildlife habitat. Arsenal® kills the hardwood and grass vegetation that typically crowds out many legumes and other herbaceous plants wildlife species, like deer, utilize for survival. The amino acids attacked by the herbicide are non-essential to animals, including insects, reptiles, amphibians, birds and mammals.

For private landowners, the cost of restoration projects has been considered prohibitive. However, it is quite common in the southern states for private landowners and investors to pay for site preparation or release projects out of their pocket. In Missouri, cost share programs can make such projects a reality for many landowners, including the owners of the Tree Farm® featured in this article. According to a BASF Corporation representative, one of the best features of pine restoration is that investments in activities like site preparation and early release applications can pay off, offering a rate of return between 8 and 15 percent. By incorporating cost share benefits into the equation, returns on investment can be even higher.

Summit Helicopter’s crew loading mix into the helicopter from the tank truck. Pine seedlings are buried under the brush in the foreground.

Site preparation and early release applications can be carried out in several ways ranging from backpack sprayers to helicopter spraying. If the critical mass of acreage is available, helicopter spraying is less expensive than any other method. Cooperation among neighboring or nearby landowners can provide this critical mass of acreage. Site preparation and early release must be done at the proper times of the year in the development of the stand, which can lead to project coordination challenges. The services of a professional forestry consultant, such as Clearwater Forest Consultants, can truly benefit landowners in a successful pine restoration.