Soil – The Decision Maker for Species Selection

Soil classification is an essential and often overlooked component used for pine tree species selection before planting. We have all seen stands of pine tree timber that are age 10, 20 or older that have performed poorly. We call these “off-site” stands. Some of the stands may be 20 plus years of age, and many trees are un-merchantable or barely merchantable. This is a result of poor species selection based upon the type of soil present. Choosing the incorrect species can potentially result in losses up to 50 percent volume potential.

Today there are many helpful tools to assist forest owners and forestry professionals in making an informed decision as to the best species – soil combination. The USDA Natural Resources Conservation Service (NRCS) has classified most soil series. Understanding and interpreting the data requires forestry training and soil management experience as is the case with each ArborGen Reforestation Advisor

It is helpful to have an understanding of soil taxonomy or classification. For a simplified approach, we can use some simple rules of thumb. For instance, there is a wide range of soils in south Alabama, south Georgia and north and central Florida. These soils can range from very deep sands to heavy clay soils. To identify the pine species to plant on a given soil, we need to understand the presence or absence of clay, the geographic location, and drainage class.

Loblolly Pine: Extensively grown throughout the Southeast U.S. About 80 percent of the pine tree seedlings grown and planted in the Southeast U.S. each year are loblolly pine. Loblolly grows well on various soil types but grows best on soils with an argillic horizon (some clay content), such as Ultisols and Alfisols. Typical soil types for loblolly are Bonifay, Orangeburg, Dothan, Tifton, etc. Loblolly pine prefers sites where the root system will not embed in low soil moisture areas. If planting upon poorly drained soils such as wet flats, then bedding is recommended.

Slash Pine: Grows along the lower coast and parts of the upper coast from the Carolinas to Texas. Slash pine is naturally adapted to grow on a wide range of soil types, including deep sandy soils that are excessively drained; moderately well-drained soils, with little to no clay content (Lakeland, Troup, Blanton); and poorly drained soils such as Spodosols (Leon, Allanton) having a high presence of organic matter and lack an argillic horizon with no clay content. However, because loblolly pine outperforms slash on all but the most poorly drained soils, only about 10 percent of the seedlings planted in the Southeast U.S. are slash pine.

Longleaf Pine: Heavily logged during the late 19th and early 20th century, longleaf pine once dominated the Southeast U.S. during settlement. It is a favorite species for those who enjoy its aesthetics, and it is widely grown on quail plantations. It grows best on upland sites with some clay content. It is often planted on deep sands but grows slowly on these soil types. Like slash pine, nearly 10 percent of the seedlings planted in the Southern U.S. are longleaf pine.

Sand Pine: Growing best on deep, excessively well-drained soils, such as Blanton and Lakeland, drought-hardy sand pine tends to develop root rot when planted in soils with clay causing the tree to become wind thrown. Commonly used for windbreaks, it is a minor species with a few million planted yearly.

Virginia Pine: Often found on some of the poorest soil types, but can grow on a wide range of soils. It is commonly found on sandy, rocky soils but can also grow on heavy clay soils. This species is often used for windbreaks.

Shortleaf Pine: This species grows best in deep, well-drained soils. Ultisols are predominantly the best types of soils for shortleaf pine, soils that are fine sandy loam or silty loam. They grow on south and west-facing slopes above the loblolly range.

Using the advice of a trained ArborGen reforestation professional, you can successfully launch a pine forest that aligns your goals of forest productivity and financial returns.

Customer Success Story: Ken Hoene, Forestry Consultant

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