Thinning and Fertilizing Southern Pine Stands of the Lower Coastal Plain: Biological and Economic Effects

1992 ◽  
Vol 16 (4) ◽  
pp. 186-193 ◽  
Author(s):  
Stephen C. Stearns-Smith ◽  
Eric J. Jokela ◽  
Robert C. Abt

Abstract The interaction between thinning and fertilization (nitrogen and phosphorus) was investigated in seven slash pine (Pinus elliottii Engelm. var. elliottii) plantations and one natural loblolly pine (Pinus taeda L.) stand in the lower Coastal Plain of the southeastern United States. Thestands ranged in age from 14-20 years when the 2² factorial (thinning X fertilization) experiments were installed. Significant thinning X fertilization interactions occurred on five tests, but the nature of the interactions was inconsistent. Fertilization responses remained significant8 years after treatment and averaged 35 ft³/ac/yr. Fertilization increased stand volume production in the chip-n-saw product class more frequently than thinning. After 8 years, thinning increased individual tree volume growth by 0.50-3.05 ft³/tree over the controls; however, thinninggenerally decreased both total stand and chip-n-saw volumes at final harvest. Economic effects were examined by determining soil expectation values (SEV) for each thinning and fertilization treatment combination for various rotation lengths using uniform economic assumptions. The treatmentcombination that maximized stand volume production was not always the best financial choice. The increased growth rates due to thinning, fertilization, or both tended to extend the optimal rotation. A 4% real cost of capital with harvest merchandizing of pulpwood and chip-n-saw product classeseconomically favored fertilization over the other treatments. However, increasing the cost of capital (6% real) or merchandizing solely for pulpwood put fertilization at a relative disadvantage. South. J. Appl. For. 16(4):186-193

2017 ◽  
Vol 47 (4) ◽  
pp. 445-457 ◽  
Author(s):  
Adam O. Maggard ◽  
Rodney E. Will ◽  
Duncan S. Wilson ◽  
Cassandra R. Meek ◽  
Jason G. Vogel

Over half of the standing pine timber volume in the southeastern USA is composed of loblolly pine (Pinus taeda L.), making it the most important tree species in the region. Future climate variability may impact productivity of these forests due to reduced water availability. To determine the effects of nutrient availability and decreased water availability on stand-level water use efficiency and growth efficiency, we examined the interactive effects of fertilization and reduced throughfall on whole-tree water use, stand-level canopy transpiration, leaf area index (LAI), and stand-level stem volume growth. This study was conducted over the 6th and 7th growing seasons (2013–2014) of a loblolly pine plantation in southeastern Oklahoma. Across all plots, throughfall reduction reduced volumetric soil water content (VWC) from 13.6% to 10.9% for soil depths of 0–12 cm and from 22.3% to 19.9% for soil depths of 12–45 cm and reduced stand volume growth from 20.9 to 17.9 m3·ha−1. Across all plots, fertilization increased LAI by 12%, increased stand volume growth from 18.3 to 20.5 m3·ha−1, and increased water use efficiency of stem volume production by 18%. These results indicate that fertilization can benefit stand growth of loblolly pine plantations even when soil moisture is limiting, in part, by increasing the efficiency of water use.


2000 ◽  
Vol 24 (1) ◽  
pp. 31-36 ◽  
Author(s):  
Barry D. Shiver ◽  
John W. Rheney ◽  
Kenneth L. Hitch

Abstract A total of 141 paired plot installations remain of the 160 that were planted with slash (Pinus elliottii Engelm.) and loblolly (P. taedaL.) pine across southeastern Georgia and northern Florida, after 14 growing seasons. Installations were evenly distributed across eight soil types. Analyses indicate that loblolly performed equal to or better than slash pine. There were no soil X species interactions. After 14 yr, loblolly pine had significantly higher survival (71% vs. 66%), stand basal area (98 vs. 81 ft2/ac), total stand volume (1857 vs. 1721 ft3/ac), merchantable stand volume (1497 vs. 1310 ft3/ac), total green weight (53 tons vs. 47 tons), and merchantable green weight (45 vs. 35 tons/ac) than slash pine. Growth over the period from age 11 to age 14 was also higher for loblolly than for slash indicating that the difference in the two species is diverging over time. South. J. Appl. For. 24(1): 31-36.


1993 ◽  
Vol 17 (3) ◽  
pp. 135-138 ◽  
Author(s):  
Eric J. Jokela ◽  
Stephen C. Stearns-Smith

Abstract Data from six fertilizer trials established in semimature southern pine stands (five slash pine, Pinus elliottii Engelm. var. elliottii; one loblolly pine, Pinus taeda L.) were analyzed to determine the efficacy of single vs. split fertilizer treatments. Both fertilizer treatments supplied an elemental equivalent of 200 lb nitrogen (N)/ac and 50 lb phosphorus (P)/ac; however, the first treatment was delivered as a single dose, and the second treatment was a split N application (i.e., 50 lb N and 50 lb P/ac (initial); 150 lb N/ac (2 yr later). Cumulative responses of fertilized plots were still significantly greater than the controls in five trials after 8 yr and averaged 43% (15.7 ft²/ac) and 39% (607 ft³/ac) for basal area and stand volume growth, respectively. In general, no significant differences in either the magnitude or duration of response were detected between the single and split N fertilizer treatments. This suggests that delaying a portion of the N application for 2 yr will not diminish the level of growth responses attained. Therefore, land managers have flexibility in using either application method when implementing midrotation fertilizer prescriptions. South. J. Appl. For. 17(3):135-138.


1980 ◽  
Vol 4 (3) ◽  
pp. 139-142 ◽  
Author(s):  
G. H. Brister ◽  
J. L. Clutter ◽  
T. M. Skinner

Abstract Forest industry in the lower coastal plain of Georgia and Florida is becoming increasingly dependent on harvests from site-prepared plantations. Sound planning for utilization of this plantation resource requires the availability of adequate growth and yield information. This paper presents total and merchantable tree volume equations for cubic foot volumes outside- and inside-bark and taper relationships derived from these equations. The equations are based on 677 trees sampled from 174 site-prepared slash pine (Pinus Elliottii Engelm.) plantations in the flatwoods of Georgia and Florida.


2019 ◽  
Vol 65 (6) ◽  
pp. 784-795
Author(s):  
Jeffrey S Ward ◽  
Jessica Wikle

AbstractSix study areas were established in 80–125-year-old upland oak stands on average sites to compare stand and individual tree growth response following two active treatments (B-level thinning, crop tree) with an unmanaged control. Initial stocking of 104 percent was reduced to 62 percent and 60 percent on the B-level and crop-tree-management plots, respectively. Approximately 7,200 board feet per acre (International ¼) were harvested on the actively managed plots with upland oaks accounting for 81 percent of pre- and 86 percent of residual stand. Eleven-year diameter and volume growth of oak sawtimber trees was greater on actively managed plots. Growth response increased with degree of release and was maintained for the length of the study. Because of the increased individual tree growth of oaks in response to release, stand volume growth of oak sawtimber did not differ between treatments. In contrast to an 11-year decline of poletimber stocking on unmanaged plots, poletimber stocking increased on managed plots as diameter growth increased in response to partial release. This may increase difficulty of regenerating oak in the future. For those mature red oak stands where traditional regeneration prescriptions will not be implemented or will be delayed, commercial harvests can be conducted without compromising stand volume growth of oak.


1993 ◽  
Vol 23 (10) ◽  
pp. 2116-2125 ◽  
Author(s):  
Dwight K. Lauer ◽  
Glenn R. Glover ◽  
Dean H. Gjerstad

Herbaceous weed control studies installed by the Auburn University Silvicultural Herbicide Cooperative to examine response to methods and duration of herbaceous weed control in eight loblolly pine (Pinustaeda L.) plantations were analyzed to determine stand response through age 9. Studies were designed to compare weed control treatments with an untreated check, weed control methods (band vs. broadcast), and weed control duration (first year vs. first 2 years). Pine growth was increased by weed control on all sites. Growth was increased by an additional year of weed control (duration) on about one-half of the sites, but did not differ between band and broadcast treatments (method). Age 9 volume response above the check averaged 27.3 m3/ha for first-year weed control and 42.9 m3/ha for the first 2 years of weed control. Individual-tree height growth between ages 7 and 9 did not differ by treatment at most sites, but stand volume growth was higher with weed control at six of the eight sites. Uniformity of individual tree size, as represented by the standard deviation of DBH adjusted for dominant height, was more dependent on survival, hardwood encroachment, and level of fusiform rust stem infection, which varied by treatment and site, than on the result of herbaceous weed control per se. Growth projections made with the least intensive weed control treatment at each site indicated that on average, merchantable volume at age 22 with weed control will equal that of an age 25 stand without weed control. Largest gains were on sites where weed control increased survival.


2007 ◽  
Vol 37 (8) ◽  
pp. 1336-1348 ◽  
Author(s):  
Mark H. Eisenbies ◽  
James A. Burger ◽  
W. Michael Aust ◽  
Steven C. Patterson

Wet-weather logging can cause severe soil physical disturbances and redistribute residues. Although some research indicates negative effects of such disturbances on individual tree growth, the long-term resilience and resistance of soils and the ameliorative effects of site preparation are not fully understood. Three 20 ha loblolly pine ( Pinus taeda L.) plantations located on fertile wet pine flats on the coastal plain of South Carolina were subjected to five treatment combinations of harvest (wet and dry) and site preparation. Mean tree heights were 10.2–11.5 m, and stand biomass ranged between 95 and 143 Mg/ha. A rank diagnostic indicates that wet-weather harvesting did not significantly change site productivity between rotations, and bedding improved site productivity. At the polypedon scale (0.04 ha), there were no significant differences in tree height, biomass, or the rank diagnostic among classes of soil physical disturbances or harvesting residues when bedding was employed. On nonbedded sites, some levels of disturbance appeared to be superior to minimally disturbed sites. Based on 10 year results, wet pine flats are apparently resistant and resilient to the effects of wet-weather harvesting.


1996 ◽  
Vol 20 (4) ◽  
pp. 188-193 ◽  
Author(s):  
James C. Fortson ◽  
Barry D. Shiver ◽  
Lois Shackelford

Abstract A series of paired plots was installed in loblolly pine plantations at 42 locations in Georgia's Piedmont and Alabama's Piedmont and Coastal Plain. One plot of each pair had all competing vegetation eliminated. The other plot was left as an uncontrolled check. Locations were stratified over two age classes (5-9 and 12-16 yr old) and three slope positions (top, midslope, and bottom). Analysis of 33 surviving locations 8 yr after treatment revealed a positive treatment effect for both individual tree (dbh and total height) and stand characteristics (basal area per acre, total volume per acre, and merchantable volume per acre). There was no difference in volume response between age classes. Slope position was not significant for the individual tree variables, but was significant for the stand variables, with midslopes responding most positively followed by bottom and then top slope positions. Over all locations, the average treatment response was approximately ½ cord/ac/yr. Economic analyses indicate that the magnitude of the response will be economical for many stumpage prices, particularly on midslope and bottom slope positions, in plantations where access and species composition make herbicide spraying possible. South J. Appl. For. 20(4):188-192.


1989 ◽  
Vol 13 (4) ◽  
pp. 204-207 ◽  
Author(s):  
Bruce E. Borders ◽  
William M. Harrison

Abstract Age 8 measurements and analysis are reported and discussed for a large side-by-side loblolly pine (Pinus taeda L.)/slash pine (Pinus elliottii Engelm.) species comparison study. It is shown that loblolly pine performed better than slash pine in CRIFF soil groups A, D, F, and G whileslash pine and loblolly pine performed similarly in CRIFF soil groups B and C. South. J. Appl. For. 13(4):204-207.


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