Declining loblolly pine stands: Symptoms, causes, and management options

摘要

By the early 1960s over 1.9 million acres of pine plantations had been established on private lands in the south as a result of both the Conservation Reserve Program and an increase in industrial forest management in the region. Because of its rapid growth and ease of establishment, loblolly pine (Pinus taeda L.) quickly became the commercial tree species of choice for southern forestry. However, as time passed, reports of declining loblolly health began to be reported throughout Alabama and the South. Symptoms included trees with short, yellow-green needles, sparse crowns, and reduced radial growth at approximately 40-50 years of age. Mortality usually occurred two to three years after symptoms appeared. Early recommendations were to reduce rotation age of loblolly pine from 70 to 60 years on these sites, maintain a basal area of 60-70 square feet per acre, and convert these stands to longleaf pine (Pinus palustris Mill.), the historic tree species in much of the area.