Annual ring widths and ring areas from 131 even-aged, natural, well-stocked stands of loblolly pine (Pinustaeda L.) in the Piedmont region were analyzed to reveal possible causes of a previously reported decline in radial growth. A linear aggregate model was used to separate independent factors that are known to contribute to radial growth variation in this species. Stand, site, and climatic conditions were reconstructed for each stand for the 36-year period 1949–1984 from previous inventories and from weather records at appropriately located stations. Within each of six 5-year age-classes, the model identified declines in both ring width and ring area associated with stand density, climate changes, and the passage of time. Regional climate first ameliorated this decline as pine stands passed from droughty conditions early in the 36-year period to a favorable climate during the middle of the period, and the decline accelerated later with the return of dry conditions toward the end of the period. The tree-ring model simulates a decline in radial increment in trees in natural pine stands between the ages of 20 and 45 years in the Piedmont which has averaged 1% per year since 1950. Part of the downward trend was attributed to increased competition, part to regional drought, and a considerable part to unidentified factors, possibly regional atmospheric deposition.

Volume (cubic foot) and weight predictions (green and dry) are presented in equations and tables for aboveground total tree and tree components of unthinned, planted iongleaf pine trees. The 111 sample trees, from 10 stands in Louisiana and Texas, were 10 to 44 years old and ranged from 1 to 21 inches dbh. The data for saplings (dbh < 5 inches) were analyzed separately from that of commercial sized trees (dbh >_ 5 inches). The linearized allometric model utilizes the variable D2H (squared diameter at breast height multipled by total tree height) to predict volumes and weights of tree components in two size classes.

A field study was conducted on an impoverished “borrow” area in the South Carolina Piedmont to determine the response of loblolly pine (Pinus taeda L.) seedlings to various fertilizer treatments. Treatments were applied for 4 consecutive years to individual seedlings outplanted for 2 years. At the end of the fertilization period, seedlings receiving N, either alone or in combination with P and/or K, were significantly taller than seedlings in other treatments. Ten years after the last fertilizer application, trees treated with N, with or without other nutrients, averaged 0.6–1.6 m taller and 23–30% larger in diameter than control trees. Merchantable tree volume was at least doubled by N application. Phosphorus and potassium, at the rates used, had no effect on growth. Percentage latewood and wood specific gravity were not altered by fertilization.

Published by: Southeastern F o r e s t Experiment S t a t i o n P a 0 , Box 2680, AshevilLe, NC 28802 PREFACEThe Problem P l a n t a t i o n s c u r r e n t l y comprise one-third of t h e pine f o r e s t a r e a i n the South, but c o n t r i b u t e only about 15 percent of m i l l f u r n i s h i n t h e region. By t h e year 2000, only a decade away, t h e a r e a of pine p l a n t a t i o n s w i l l increase modestly, but they w i l l by then provide about 50 percent of t h e South's softwood f i b e r supplies. A t t h e very l e a s t , t h i s s u b s t m t i a l s h i f t i n our resource base w i l l r e q u i r e us t o make rapid technological and market adaptations. Greater impacts of t h e change could be r e f l e c t e d i n poorer wood q u a l i t y , reduced product y i e l d s from p l a n t a t i o n wood, adverse e f f e c t s on s o l i d wood and f i b e r products, and l o s s of market share t o o t h e r wood-producing regions o r t o nonwood products.This s u b s t a n t i a l , rapid change i n our resource base should mandate immediate s t r a t e g i c planning and research. I f the South i s t o r e t a i n i t s competitive advantage and i t s market share i n softwood-based i n d u s t r y , w e must a s s e s s t h e impacts of t h e changing resource on our manufacturing processes. A cooperative e f f o r t i s needed t o gain s c i e n t i f i c knowledge of growth and u t i l i z a t i o n of p l a n t a t i o n wood, t o develop regional s t r a t e g i c plans t o develop and implement new manufacturing and f o r e s t management technology, and t o produce and market goods t h a t take advantage of our resource. Most o t h e r major w~r l d softwood producers--the P a c i f i c Northwest, B r i t i s h Columbia, and New Zealand--have developed i n t e g r a t e d research and planning e f f o r t s t o deal with t h e i r second-growth softwood resources. The South should do t h e same now.The Workshop S c i e n t i s t s , manufacturers and f o r e s t managers were i n v i t e d t o t h i s workshop t o i d e n t i f y t h e problems and opportunities associated with the changing southern pine resource base. Attendees p a r t i c i p a t e d i n commodity group sessions t o i d e n t i f y information needs t h a t may then be used t o guide f o r e s t management and manufacturing research associated with t h e pine p l a n t a t i o n resources.These proceedings contain overview papers presented a t t h e workshop and t h e recommended research information needs i d e n t i f i e d i n each group session. It i s hoped t h a t t h i s workshop w i l l serve a s t h e b a s i s f o r f u t u r e i n t e g r a t e d research and planning e f f o r t s f o r t h e southern softwood industry. P l a n t a t i o n s have s t e a d i l y increased i n area during t h e last t h r e e decades, and t h i s trend is expected t o e s c a l a t e . Rates of change i n t h e p l a n t a t i o n resource d i f f e r by ownership, On a l l ownerships t h e area o f n a t u r a l p i...

Approximately two-thirds of the loblolly pine forests in the South are regenerated by natural or direct seeding. Many of these stands are overstocked, challenged by hardwood and herbaceous competition, or lacking in fertility. Due to minimal management inputs, the initial diameter growth rates for stems in these stands are slow in many instances. Consequently, the juvenile wood cores in the boles of these trees are small relative to those of faster grown plantation stems. Thinning of such a stand at age 21 and application of fertilizer at age 23 dramatically increased diameter growth at breast height for all crown classes. The proportion of earlywood to latewood and the specific gravity of annual rings were not affected by either treatment, and they were highly favorable for quality sawn lumber. Earlier treatment of the study stand to coincide with the transition phase from juvenile to mature wood formation at age 15 would likely have optimized the future production of quality sawlogs. Timing of these treatments could best be gauged by the ring growth pattern of codominant trees in the stand and the stabilization of the annual earlywood to latewood ratio. South. J. Appl. For. 15(1):5-9.