Approaches to model mid-rotation treatment effects in loblolly pine plantations in the Southeastern United StatesThis article is part of a larger document. View the larger document here.
Loblolly pine (Pinus taeda L.) plantations are extensive in the Southeastern United States and represent a significant component of the forest products market in this region. For optimal stand-level management decisions, the growth response to any combination of mid-rotation silvicultural treatments like fertilization, thinning, or competing vegetation management needs to be accurately predicted over the long term. We present a review of the most common mid-rotation silvicultural treatments applied in loblolly pine plantations and provide a conceptual framework about their effects. Three theoretical expected types of responses are illustrated as a guide for better and more comprehensive modeling approach selection. Preliminary exploratory data analysis of remeasured plots from a mid-rotation treatment study established by the Plantation Management Research Cooperative at the University of Georgia indicates that basal area growth after thinning follow a Type I response and treatments such as thinning + fertilization or thinning + fertilization + vegetation control can follow either Type I or Type II responses. Finally, some thoughts are provided on how to improve the prediction accuracy of growth-and-yield models considering mid-rotation treatments.