The Importance of Tree Genetics in Forest Management

In the past, foresters who oversaw planting had limited knowledge or access to information about seedling genetics. The thought process used to be to find a green seedling with a good root system, plant it, and hope for the best. Silvicultural treatments like herbicides, fertilizer, and thinnings have long been utilized to help encourage growth in southern pine plantations. However, once a seedling is planted, one can never change the growth patterns and characteristics associated with that tree’s genetics. Each seedling represents an investment that the landowner will carry for a quarter of a century or longer. At American Forest Management, we understand the importance of making wise investments for future generations, so we embrace advancements in science and technology.

Tree breeding in loblolly and slash pine for improved performance has been occurring for more than half a century, but this is not a quick process. Loblolly has long been the focus of genetic improvement in the southeast, with slash improvement occurring to a lesser extent. Overall, genetic enhancements have led to trees with enhanced productivity, rust resistance, and straightness. We also have access to data that helps ensure landowners are selecting families that are well-adapted to their specific region. For example, minimum winter temperatures are an important factor in the selection process. Still, with increasing temperatures, more studies are being done to push coastal families into the Piedmont, which often exhibits better growth rates than typical Piedmont selections.

In recent years, several pulpwood mills have shut down across the southeast, devastating local pulpwood markets and causing landowners to question what’s next. To address this issue, many are turning to seedlings with a high level of genetic improvement and an emphasis on genetics that produce the straightest trees possible, thus decreasing pulpwood yields and maximizing sawtimber potential. This also allows the landowner to plant lower densities at establishment, which maximizes diameter growth, cuts down on the reliance upon multiple thinnings, and helps offset the higher seedling cost. Ultimately, matching genetics to local markets, soil types, and landowner objectives is key.

So, what’s next? In the coming years, we hope to have better stand-level data on genetics to help improve investment modeling. Wood density, branch characteristics, genomics, pitch canker, and other disease resistances are additional areas of study. With increased interest and funding initiatives for longleaf, we may soon see attempts at furthering genetic improvement in this species as well. With urban sprawl and alternative land use competition like solar, tree breeding plays a crucially important role in the appeal of reforestation, ensuring we have forests to manage for generations to come.