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

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.

1993 ◽  
Vol 23 (10) ◽  
pp. 2126-2132 ◽  
Author(s):  
Glenn R. Glover ◽  
Bruce R. Zutter

A site-preparation study installed in 1959 in Fayette County, Alabama, U.S.A., provides data to evaluate long-term effects of varying densities of hardwood on loblolly pine (Pinustaeda L.) plantation growth, yield, and stand structure. Six treatments (hand girdle; bulldoze scarification; herbicide applied to axe frill, chain frill, and with an injector; and an untreated check) were installed as a randomized complete block with five replications. Periodic measurements of pine and hardwood size and density show that higher hardwood densities existing early in the pine plantation had a substantial negative effect on loblolly pine survival and basal area yield, with the bulldoze and herbicide treatments having less hardwood and higher survival and stand basal area. Pine total height and diameter at breast height were reduced by increasing hardwood density early in the life of the plantation, but size of surviving trees differed little among treatments at later ages, except on plots where most pine trees were suppressed by hardwoods. Strong relationships between pine basal area per hectare at age 27 and both number of hardwood stems at age 3 and percentage of stand basal area in hardwood at age 6 were noted. These relationships indicate promise for predicting long-term growth and yield of loblolly pine plantations from early measures of hardwood interference.


Forests ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 556
Author(s):  
Mauricio Zapata-Cuartas ◽  
Bronson P. Bullock ◽  
Cristian R. Montes ◽  
Michael B. Kane

Intensive loblolly pine (Pinus taeda L.) plantation management in the southeastern United States includes mid-rotation silvicultural practices (MRSP) like thinning, fertilization, competitive vegetation control, and their combinations. Consistent and well-designed long-term studies considering interactions of MRSP are required to produce accurate projections and evaluate management decisions. Here we use longitudinal data from the regional Mid-Rotation Treatment study established by the Plantation Management Research Cooperative (PMRC) at the University of Georgia across the southeast U.S. to fit and validate a new dynamic model system rooted in theoretical and biological principles. A Weibull pdf was used as a modifier function coupled with the basal area growth model. The growth model system and error projection functions were estimated simultaneously. The new formulation results in a compatible and consistent growth and yield system and provides temporal responses to treatment. The results indicated that the model projections reproduce the observed behavior of stand characteristics. The model has high predictive accuracy (the cross-validation variance explained was 96.2%, 99.7%, and 98.6%; and the prediction root mean square distance was 0.704 m, 19.1 trees ha−1, and 1.03 m2ha−1 for dominant height (DH), trees per hectare (N), and basal area (BA), respectively), and can be used to project the current stand attributes following combinations of MRSP and with different thinning intensities. Simulations across southern physiographic regions allow us to conclude that the most overall ranking of MRSP after thinning is fertilization + competitive vegetation control (Fert + CVC) > fertilization only (Fert) > competitive vegetation control only (CVC), and Fert + CVC show less than additive effect. Because of the model structure, the response to treatment changes with location, age of application, and dominant height growth as indicators of site quality. Therefore, the proposed model adequately represents regional growth conditions.


2002 ◽  
Vol 26 (1) ◽  
pp. 37-42 ◽  
Author(s):  
Stacey W. Martin ◽  
Barry D. Shiver

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.


1999 ◽  
Vol 29 (7) ◽  
pp. 979-984 ◽  
Author(s):  
Dwight K Lauer ◽  
Glenn R Glover

The relationship between age-5 pine height and vegetation cover was estimated for loblolly pine (Pinus taeda L.) and slash pine (Pinus elliottii Engelm.) stands using regression analysis. This paper utilizes results from four locations of a vegetation control study that included herbicide treatments to control woody shrub and herbaceous vegetation. Age-5 average dominant height was predicted from first-year herbaceous cover, untreated first-year shrub cover, and fifth-year shrub cover. Dominant height increased 0.5 m for each decrease of about 30% in either first year herbaceous cover, untreated first-year shrub cover, or year-5 shrub cover. Lack of vegetation control on beds where vegetation was allowed to recolonize before planting reduced dominant height an additional 0.5 m. A competition index was constructed that estimates the difference between "potential" and actual age-5 pine height. Stand-level models were developed to link age-5 pine height and occupancy of competing vegetation to quadratic mean DBH, specific DBH percentiles, and stand basal area. The effects of interspecific competition on stand basal area and diameter percentiles could be accounted for through the effects of competing vegetation on dominant height except for treatments that did not control woody shrubs.


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.


1989 ◽  
Vol 13 (1) ◽  
pp. 17-21 ◽  
Author(s):  
James D. Haywood ◽  
James D. Burton

Abstract Productivity of upland loblolly pine (Pinus taeda L.) plantations was studied under seven site preparation treatments and five soil classes, with and without fertilizer, in the West Gulf Coastal Plain. Generally, the chop-burn-harrow and shear-windrow-harrow treatments resulted in themost basal area (ave. 112 ft²/ac), but the chop-burn-harrow treatment produced the most fiber (2,109 ft³/ac) after 12 growing seasons. Harrowing as an additional treatment after chopping-and-burning increased productivity by 394 ft³/ac over the chop-burn treatment. The leastproductive treatments were underplant-inject and shear-windrow. Generally, basal area per acre was comparatively high on the silty, slowly permeable clay, and very slowly permeable clay soils (ave. 105 ft ²/ac). Two of the soils, silty and slowly permeable clay, had comparatively highvolume production (ave. 1,878 ft³/ac). The least productive sites had gravelly subsoils. Generally, phosphorus fertilization did not influence pine productivity. South. J. Appl. For. 13(1):17-21.


2005 ◽  
Vol 29 (4) ◽  
pp. 205-214 ◽  
Author(s):  
Thomas R. Fox ◽  
Kevin H. Kyle ◽  
Lisa J. Andrews ◽  
W. Michael Aust ◽  
James A. Burger ◽  
...  

Abstract A site preparation study was established in 1968 at three locations in the Coastal Plain of Virginia. Three treatments were installed in a randomized complete block design: (1) chop, (2) bed, and (3) ditch. In 1978, four fertilizer treatments were superimposed on the site preparation study: (1) check, (2) phosphorus (P) only, (3) P + nitrogen (N), and (4) P + N + lime, converting it into a split-plot design. At age 33 years, height of the dominant loblolly pine in the ditch treatment was significantly greater than in the other site preparation treatments. However, there were no differences in stand density, diameter at breast height (dbh), basal area, or volume because of site preparation. This contrasts with the data collected at age 21 years, when total volume in both the bed treatment and the ditch treatment was greater than in the chop treatment. Changes in water table depths through time were the probable cause for decreased response to bedding and ditching. There was a large response to fertilization through age 33 years in this study. The P + N + lime treatment had significantly greater dbh, basal area, and volume than the other fertilizer treatments, which significantly increased pine stumpage value. The size of the growth response was greater at age 33 years than it was at age 21 years. Soil and foliage analysis suggests that the sustained growth response at this site was due to the added Ca. South. J. Appl. For. 29(4):205–214.


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.


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