Timber University

Emerald ash borer continues to spread across the South, threatening ash trees in forests, urban areas, and important bottomland hardwood ecosystems. In this episode of Timber University, Dr. Colin Bonser, an entomologist with Forest Health Protection in the USDA Forest Service, joins us to discuss emerald ash borer, how it is detected and monitored, and what its continued spread could mean for southern forests. Dr. Bonser explains how emerald ash borer attacks ash trees by feeding on vascular tissue beneath the bark, eventually girdling and killing the tree. We discuss common signs of infestation, including crown dieback, epicormic branching, D-shaped exit holes, and increased woodpecker activity. The conversation also covers Forest Service monitoring efforts, including the use of prism traps and attractant lures to detect new infestations. Recent detections in Louisiana are particularly important for Mississippi. Bonser discusses new detections in parishes along the Mississippi River and ongoing monitoring on the Mississippi side, including the Delta National Forest. Because ash is an important component of southern bottomland hardwood forests, widespread mortality could significantly alter forest composition and create longer-term ecological consequences. The episode also examines management options. Individual high-value ash trees can sometimes be protected through systemic insecticide treatments, but treating large numbers of trees is costly and generally impractical at the forest scale. We also discuss the economic consequences of losing ash, including impacts on timber value and industries that have historically relied on ash for products such as furniture, flooring, baseball bats, and musical instruments. This episode is a useful listen for forest landowners, consulting foresters, forest health professionals, forestry students, Extension professionals, and anyone interested in invasive species, bottomland hardwood management, and the future of ash in southern forests. Questions for Timber University can be sent to [email protected]

Forest management decisions are made under biological, financial, and market conditions that can change considerably during the life of a stand. In this episode of Timber University, Dr. Adam Polinko, formerly of Mississippi State University (now at Northern Arizona University), joins us to discuss two applied research projects examining how landowners and foresters can respond to those challenges: chemical thinning in overstocked pine stands and the long-term development of mixed cherrybark oak and sweetgum plantings. Dr. Polinko's research focuses broadly on silviculture and forest stand dynamics, including how forests respond to disturbances such as thinning, harvesting, and other management interventions. The first part of the conversation examines whether chemical thinning could help landowners manage dense pine stands that can no longer be commercially thinned because of weak pulpwood markets. Dr. Polinko explains how a modified "hack-and-squirt" treatment can be used to thin a stand from below by killing smaller trees in place, opening growing space for larger trees, and accelerating a process that would otherwise occur gradually through natural self-thinning. We discuss how chemical thinning differs from conventional row thinning and why it may be particularly useful on smaller properties where logging access, tract size, or limited markets make a commercial thinning difficult. Because the work can be completed by people on foot using relatively simple equipment, it could give some landowners a practical way to place an overstocked stand back on a more productive growth trajectory. The episode also explores the risks and trade-offs of killing trees in place. The research team is examining how treatment timing affects Ips engraver beetles, southern pine beetles, tree stress, and mortality. The study will also evaluate how standing dead trees, dry needles, fallen woody material, and changing fuel loads may influence wildfire behavior. At the same time, increased sunlight reaching the forest floor could stimulate vegetation that provides additional forage and habitat benefits for wildlife. The second half of the episode turns to a mixed-species study established in the early 1980s to examine the development of planted cherrybark oak and sweetgum. The study was designed to test observations from natural stands suggesting that sweetgum may initially grow as fast as, or faster than, cherrybark oak, while the oak eventually overtakes it. Recent measurements indicate that sweetgum remained highly competitive for approximately the first 25 years, after which its height growth began to level off, and the cherrybark oak pulled ahead. The result today is a stand containing large, high-quality cherrybark oak and much smaller sweetgum. Dr. Polinko explains that sweetgum may provide a valuable "training effect" for cherrybark oak. Competition between the species can help the oak maintain apical dominance, straighter stems, smaller branches, and better overall form than might develop in a widely spaced, single-species oak planting. The study also provides a rare opportunity to compare mixed stands directly with nearby pure sweetgum and mostly pure cherrybark oak stands on the same site. The conversation highlights why mixed-species forestry may offer more than biological benefits. Growing different species together can diversify future management options, reduce dependence on a single timber market, and give landowners greater flexibility when deciding which species to thin, retain, or manage as the final crop. Because forest rotations are long and markets can change much faster than stands can be replaced, this kind of biological and financial diversification may become increasingly valuable. This episode is a useful listen for forest landowners, consulting foresters, wildlife managers, forestry students, researchers, Extension professionals, and anyone interested in pine thinning, mixed-species management, stand dynamics, forest health, and the challenge of managing forests under changing market conditions. Questions for Timber University can be sent to [email protected]

Forest inventory and timber cruising provide the information landowners and foresters need to understand what is growing on a property, how much timber is present, and how that timber should be managed or valued. In this episode of Timber University, Dr. Josh Granger from Mississippi State University joins us to discuss the different methods used to measure forests and why a well-designed inventory can be one of the most important investments a forest landowner makes. Dr. Granger is an Associate Professor in Mississippi State University's Department of Forestry, where he teaches dendrology, forest measurements, and forest description and analysis. His work helps students develop the practical skills needed to identify trees, measure forest resources, design timber cruises, and use inventory data to support forest management decisions. In this conversation, we discuss why the purpose of an inventory should determine how it is designed. Dr. Granger explains the differences among fixed-area plots, prism or variable-radius sampling, strip cruises, nested plots, and 100-percent inventories. He also discusses why no single method is best for every situation and how foresters often combine methods to efficiently collect the information needed. We also explain basal area, trees per acre, total height, merchantable height, and the level of precision needed for different types of forestry work. The conversation explores why a diameter measurement to the nearest tenth of an inch may be useful for research, growth monitoring, or carbon accounting, while broader diameter classes may be adequate for some operational timber cruises. The episode also emphasizes the financial importance of obtaining a reliable inventory before buying or selling timber. Without an independent estimate of timber volume, quality, and product composition, landowners may have little basis for determining whether an offer reflects the true value of their timber. Forest inventories can also support property appraisals, timber-basis calculations, casualty-loss documentation, carbon projects, wildlife management, invasive-species monitoring, and long-term assessments of forest growth and condition. This episode is a useful listen for forest landowners, consulting foresters, forestry students, timber buyers, land managers, appraisers, extension professionals, and anyone interested in understanding how forests are measured and valued. Questions for Timber University can be sent to [email protected].

Can forest landowners deduct residual soil fertility as some farmers do? In this episode, Shaun and Brady examine the growing interest in the residual fertility tax deduction, explain the relevant IRS tax provisions, and discuss why these strategies may apply to agriculture but generally not to forestry. They also cover the legal uncertainty surrounding aggressive soil nutrient deductions and what forest landowners should know before pursuing them. Special Thanks to Dr. Yanshu Li at The University of Georgia for providing section code interpretation and Kristine Tidgren, Director of the Center for Agricultural Law and Taxation, for her very helpful work in this area that was used for the background and relevant cases discussed in the episode.  Have Questions? If you've encountered this issue in practice or have experience with residual fertility deductions in forestry or agriculture, the hosts would love to hear from you. Email: [email protected]

In this Q&A episode, Brady and Shaun answer listener and landowner questions on three practical forestry topics: whether diesel or dish soap should be used as surfactants in herbicide applications, what landowners should consider before converting industrial timberland into recreational or early successional habitat, and how soil properties influence which tree species can successfully grow on a site. The episode emphasizes a recurring Timber University theme: forestry decisions depend on objectives. A practice may be silviculturally possible, but that does not mean it is legal, consistent, financially sound, or appropriate for a specific landowner's long-term goals.