scholarly journals Impacts of Vegetation Control, Genetic Improvement and their Interaction on Loblolly Pine Growth in the Southern United States—Age 12 Results

2002 ◽  
Vol 26 (1) ◽  
pp. 37-42 ◽  
Author(s):  
Stacey W. Martin ◽  
Barry D. Shiver
Keyword(s):  
South Carolina ◽  
Loblolly Pine ◽  
Coastal Plain ◽  
Genetic Improvement ◽  
First Generation ◽  
Single Family ◽  
Genetic Stock ◽  
Vegetation Control ◽  
Mechanical Site Preparation ◽  
Competition Control

Abstract A designed study was established in the Coastal Plain of Georgia and northern Florida, and in the Piedmont of South Carolina, Georgia, and Alabama with the objectives of evaluating the impacts of first-generation genetic improvement and of combining genetic improvement and vegetation control on yields of loblolly pine. The two levels of competition control were either none, other than that provided by the operational mechanical site preparation, or complete competition control. Genetic treatments consisted of unimproved seed stock, bulk lot first-generation improved stock or single family first-generation improved stock. In terms of total volume, increases up to 45% (882 ft3/ac) and 39% (863 ft3/ac) were obtained from using complete vegetation control in the Coastal Plain and Piedmont regions, respectively. Improved genetic stock increased total volume an average of 11% (246 ft3/ac) to 16% (364 ft3/ac) in the Coastal Plain and 12% (277 ft3/ac) to 19% (445 ft3/ac) in the Piedmont for bulk lot and single families, respectively. For total volume, the effects of competition control and genetics were additive, indicating the managers should obtain the full benefit of these two treatments. In both regions, improved genetics significantly reduced the percent fusiform infection. In addition, no statistically significant differences were detected between bulk lot and single family plantings across all dependent variables. South. J. Appl. For. 26(1):37–42.

Does It Pay to Conduct Midrotation Competition Control and/or Fertilization? Results from Two Thinned Loblolly Pine Studies in the Coastal Plain of Georgia

2021 ◽  
Author(s):  
Yanshu Li ◽  
E David Dickens ◽  
Matthew Sault ◽  
Jacek P Siry ◽  
Robert L Izlar ◽  
...  
Keyword(s):  
Loblolly Pine ◽  
Coastal Plain ◽  
Growth Response ◽  
Critical Role ◽  
Combined Treatment ◽  
Treatment Costs ◽  
Limiting Factors ◽  
Economic Returns ◽  
Vegetation Control ◽  
Competition Control

Abstract The effects of midrotation competition control and fertilization were studied in two loblolly pine stands in the Coastal Plain of Georgia. The use of fertilizer or herbicide alone did not enhance wood yields above the control, which negates the cost spent to conduct these practices. The combined treatment of fertilization and herbicide promoted higher average pine annual increment and greater proportion of sawtimber. Site limiting factors, most likely both competing woody vegetation and low nutrient status, largely determined the effectiveness and priority of midrotation treatments. The economic returns of the combined treatment varied considerably depending on stumpage prices, treatment costs, and magnitude and duration of the growth response. Sawtimber prices (absolute value and relative to pulpwood and chip-n-saw) play a critical role in the marginal returns of midrotation treatments. Continued depressed sawtimber prices will discourage private landowners from investing in midrotation vegetation control and fertilization. Study Implications: Midrotation fertilization and vegetation control can be attractive silvicultural treatments to increase timber volume and economic returns. Assessment of site variables that limit growth, especially soil fertility and plant competition, must be conducted before prioritization of treatments. The economic returns of midrotation treatments vary greatly depending on treatment costs, stumpage prices, and magnitude and duration of pine growth response compared with controls. The pine growth response of particular concern is ingrowth of trees into the sawtimber size class and growth of sawtimber-sized trees. Sawtimber prices play a critical role in the marginal internal rate of return of the additional investment. Lackluster timber prices (especially sawtimber prices) may render investment in midrotation fertilization and vegetation control unattractive and have detrimental effects on timber supply and forest health of the region in the long term.

scholarly journals Twelve-Year Results of a Loblolly Pine Site Preparation Study in the Piedmont and Upper Coastal Plain of South Carolina, Georgia, and Alabama

2002 ◽  
Vol 26 (1) ◽  
pp. 32-36 ◽  
Author(s):  
Stacey W. Martin ◽  
Barry D. Shiver
Keyword(s):  
South Carolina ◽  
Loblolly Pine ◽  
Coastal Plain ◽  
Chemical Treatment ◽  
Basal Area ◽  
Site Preparation ◽  
Growth And Yield ◽  
Control Treatment ◽  
Vegetation Control ◽  
Stand Basal Area

Abstract A designed experimental study was installed at 25 separate locations in the Piedmont and Upper Coastal Plain regions of South Carolina, Georgia, and Alabama with the objective of evaluating the effects of different site preparation treatments, both chemical and mechanical, on growth and yield of cutover site-prepared loblolly pine (Pinus taeda L.) plantations. The following six site preparation treatments were included: (1) burn, (2) chop and burn, (3) shear, pile and disk, (4) chop, herbicide and burn, (5) herbicide and burn, and (6) herbicide, burn and complete vegetation control. The herbicide, burn and complete vegetation control treatment significantly increased mean dbh, mean height, stand basal area, and total and merchantable volume compared to all other treatments. The burn-only treatment consistently ranked worst compared to all other treatments. There were significant differences in mean dbh, mean height, stand basal area, and total and merchantable volume between: (1) the herbicide and burn, which is an operational chemical treatment, and (2) the average of the chop and burn treatment and the shear, pile and disk treatment, which are operational mechanical treatments. In all cases the operational chemical treatment performed significantly better than the average of the two operational mechanical treatments. Average 12-yr-old merchantable volumes (ft3/ac) across all locations by treatment were: burn (846), chop and burn (1,445), shear, pile and disk (1,740), chop, herbicide and burn (1,669), herbicide and burn (1,919), and herbicide, burn and complete vegetation control (2,546). There were no apparent trends in percent fusiform infection levels across site preparation treatment intensity levels. South. J. Appl. For. 26(1):32–36.

scholarly journals Loblolly Pine—Pushing the Limits of Growth

2001 ◽  
Vol 25 (2) ◽  
pp. 69-74 ◽  
Author(s):  
Bruce E. Borders ◽  
Robert L. Bailey
Keyword(s):  
Loblolly Pine ◽  
Annual Increment ◽  
Complete Control ◽  
Vegetation Control ◽  
Mechanical Site Preparation ◽  
Yield Production ◽  
The World ◽  
Intensively Managed ◽  
Pinus Taeda L ◽  
Production Areas

Abstract With mean annual increments up to 5.4 cords/ac/yr, six loblolly pine (Pinus taeda L.) research sites in Georgia produced yields on par with other results from intensively managed loblolly plantations around the world. Cultural treatments in the Georgia study include complete control of vegetation other than the planted pines with multiple applications of herbicide, annual fertilization, the combination of complete vegetation control and annual fertilization, and an intensive mechanical site preparation treatment. Complete vegetation control resulted in higher yield production at ages 10 to 12 yr than the intensive mechanical treatment at all locations. This regime also resulted in higher yield production than the annual fertilization treatment at four of six locations. Volume mean annual increment for 10- to 12-yr-old plantations with the combination treatment of complete vegetation control and annual fertilization ranged from 325 to 490 ft3/ac, growth rates comparable to those obtained at other high biomass production areas throughout the world. Our economic evaluation based on these results shows that 8 to 12% real rates of return are feasible from investments in intensive loblolly pine plantations in the southeastern United States. South. J. Appl. For. 25(2):69–74.

Changes in site productivity and the recovery of soil properties following wet- and dry-weather harvesting disturbances in the Atlantic Coastal Plain for a stand of age 10 years

2007 ◽  
Vol 37 (8) ◽  
pp. 1336-1348 ◽  
Author(s):  
Mark H. Eisenbies ◽  
James A. Burger ◽  
W. Michael Aust ◽  
Steven C. Patterson
Keyword(s):  
South Carolina ◽  
Loblolly Pine ◽  
Coastal Plain ◽  
Tree Height ◽  
Site Preparation ◽  
Atlantic Coastal Plain ◽  
Site Productivity ◽  
Individual Tree ◽  
Wet Weather ◽  
Wet Pine Flats

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.

scholarly journals Intensive Forest Management Affects Loblolly Pine (Pinus taeda L.) Growth and Survival on Poorly Drained Sites in Southern Arkansas

2006 ◽  
Vol 30 (2) ◽  
pp. 79-85 ◽  
Author(s):  
M.S. Rahman ◽  
M.G. Messina ◽  
R.F. Fisher
Keyword(s):  
Forest Management ◽  
Pinus Taeda ◽  
Loblolly Pine ◽  
Site Preparation ◽  
Growth And Survival ◽  
Vegetation Control ◽  
Mechanical Site Preparation ◽  
Intensive Forest Management ◽  
Tree Survival ◽  
Pinus Taeda L

Abstract We investigated if intensive forest management could enhance loblolly pine seedling growth and survival on West Gulf flatwoods where winter and spring waterlogging and frequent summer drought limit loblolly pine performance. Fertilization, chemical vegetation control, and mechanical site preparation (combined bedding and ripping) were tested in different combinations on six sites established in southern Arkansas in early 1999. Loblolly pine (Pinus taeda L.) seedling performance was monitored in the first two growing seasons (1999 and 2000) and fifth growing season (2003) after planting. Fertilization increased growth in all years. Mechanical site preparation affected only height and only until year 2. There was no effect of chemical vegetation control in any measurement year, although chemical vegetation control resulted in greater growth in combination with fertilization than did either treatment applied separately. Tree survival averaged 92% a few months after planting and then decreased significantly at year 1 (77%), and remained comparable until year 5, the last year data were collected. Tree survival was not affected by mechanical site preparation, fertilization, or chemical vegetation control. Intensive forest management can increase loblolly pine seedling growth and survival on poorly drained sites in the West Gulf.

Woody and herbaceous competition effects on stand dynamics and growth of 13-year-old natural, precommercially thinned loblolly and shortleaf pines

1999 ◽  
Vol 29 (7) ◽  
pp. 947-959 ◽  
Author(s):  
Michael D Cain
Keyword(s):  
Pinus Taeda ◽  
Coastal Plain ◽  
Stand Dynamics ◽  
Vegetation Control ◽  
Competition Control ◽  
Loblolly Pines ◽  
Volume Production ◽  
The Mean ◽  
Four Levels ◽  
Pinus Taeda L

Stand dynamics of naturally regenerated, even-aged, loblolly pines (Pinus taeda L.) and shortleaf pines (P. echinata Mill.) were examined on the Upper Coastal Plain of southeastern Arkansas, U.S.A., following four levels of competition control. Treatments included a check (Ck) with no competition control, woody control (WC), herbaceous control (HC), and total control (TC) of nonpine vegetation. After pines became established from natural seeding, herbicides were used to control herbaceous plants for four consecutive years and woody plants for five consecutive years. At age five, 1235 crop pines/ha were retained and all noncrop pines >1.5 m tall were precommercially hand thinned. Although 93% of crop pines on Ck plots were judged free-to-grow 13 years after establishment, crop pines on vegetation control plots were larger (P [Formula: see text] 0.001) in mean diameter at breast height, total height, and volume per tree. From age 5 through 13 years, crop pine diameter growth increased on WC plots and decreased on HC plots because of hardwood competition in the latter treatment. At age 13, mean pine volume production was 48% greater (P < 0.01) on plots that received competition control than on Ck plots (160 m3·ha-1); TC resulted in 31% more (P < 0.01) volume (282 m3·ha-1) than the mean of WC and HC plots; and there was no difference (P = 0.15) between the latter two treatments.

Relationships between loblolly pine yield and woody plant diversity in Virginia Piedmont plantations

1999 ◽  
Vol 29 (7) ◽  
pp. 1065-1072 ◽  
Author(s):  
Lisa E Schabenberger ◽  
Shepard M Zedaker
Keyword(s):  
Species Richness ◽  
Loblolly Pine ◽  
Plant Diversity ◽  
Woody Plant ◽  
Basal Area ◽  
Plant Species Richness ◽  
Shannon Index ◽  
Vegetation Control ◽  
Virginia Piedmont ◽  
Competition Control

This study was established to determine the effects of competition control on loblolly pine (Pinus taeda L.) yield and woody plant diversity in Virginia Piedmont plantations 12-14 years of age. In a factorial experiment, loblolly pine and competing woody vegetation were analyzed at eight levels of competition control: total, two-thirds, one-third, or no woody stem control in combination with either total or no herbaceous vegetation control. Pine yield increased linearly with increasing levels of woody control intensity. As woody control increased, noncrop woody plant basal area and woody plant diversity (Shannon index (H')) in the canopy decreased. Woody plant species richness in the canopy was reduced by herbaceous control and by total woody control. Percent woody cover, H', and species richness in the understory were not affected at any level of competition control. Regression analysis was used to examine relationships between loblolly pine yield, noncrop woody dominance and canopy plant diversity (H'). Pine yield was negatively correlated (R2 = 0.74) with the percentage of noncrop woody basal area (PNCW BA) in the canopy, while canopy diversity was proportional to PNCW BA (R2 = 0.97). Canopy diversity was inversely related to pine yield (R2 = 0.77), with a high trade-off in diversity at low yield levels, but with decreasing sensitivity as pine yield increased.

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