Loblolly pine growth response to herbaceous vegetation control at different planting densities

1999 ◽  
Vol 29 (7) ◽  
pp. 960-967 ◽  
Author(s):  
Harold Quicke ◽  
Glenn Glover ◽  
Ralph S Meldahl
Keyword(s):  
Loblolly Pine ◽  
Basal Area ◽  
Planting Density ◽  
Herbaceous Vegetation ◽  
Vegetation Control ◽  
Volume Yield ◽  
Volume Response ◽  
Adjustment Term ◽  
Pinus Taeda L ◽  
Positive Effect

Growth of Pinus taeda L., with and without control of competing herbaceous vegetation, was evaluated over 15 years at planting densities ranging from 747 to 2990 trees/ha. A height response to vegetation control of 0.9 m at age 5 decreased to 0.3 m at age 15. Convergence in the cumulative height between treated and untreated stands did not translate into converging basal area and volume yield. For 1500 and 2200 trees/ha, volume response to early vegetation control increased to age 15. For 800 trees/ha volume gains increased to age 12 and were stable between ages 12 and 15. Higher densities apparently captured more of the site resources made available through vegetation control. Age-15 volume gains for 2200, 1500, and 800 trees/ha were 71 (23%), 48 (17%), and 19 m3·ha-1 (8%), respectively. A separate adjustment term in height and basal-area models captured the short-term positive effect of vegetation control on height growth and longer term basal-area responses. Previously published height and basal-area models were modified to account for planting-density effects.

Early Results from an Old-Field Loblolly Pine Spacing Study in the Georgia Piedmont with Competition Control

1993 ◽  
Vol 17 (4) ◽  
pp. 193-196 ◽  
Author(s):  
L. V. Pienaar ◽  
B. D. Shiver
Keyword(s):  
Loblolly Pine ◽  
Basal Area ◽  
Planting Density ◽  
Yield Potential ◽  
Stem Volume ◽  
Annual Increment ◽  
Average Growth ◽  
Vegetation Control ◽  
Early Results ◽  
Georgia Piedmont

Abstract The study reported here provides information on the yield potential of improved loblolly pine seedlings planted on marginal agricultural cropland in the Georgia Piedmont with control of herbaceous competition. Early growth rates greatly exceed those in existing plantations established on cutover and mechanically site-prepared land in this region without additional control of competing vegetation. After 8 growing seasons, average tree height, average dbh, basal area per acre, and stem volume per acre were all influenced by planting density, but the mean annual increment of merchantable volume (trees 4.0 in. dbh and bigger to a 2.0 in. top diameter) at age 8 yr, for planting densities of 400 to 1000 trees/ac, was 230 ft³, or approximately 3 cords/ac/yr. This is more than twice the average growth rate in this region of cutover and mechanically site-prepared loblolly plantations without additional vegetation control. These results should be of particular interest to prospective participants in the Conservation Reserve Program (CRP). South. J. Appl. For. 17(4):193-196.

Stand level pine response to occupancy of woody shrub and herbaceous vegetation

1999 ◽  
Vol 29 (7) ◽  
pp. 979-984 ◽  
Author(s):  
Dwight K Lauer ◽  
Glenn R Glover
Keyword(s):  
Loblolly Pine ◽  
Basal Area ◽  
Pinus Elliottii ◽  
First Year ◽  
Shrub Cover ◽  
Herbaceous Vegetation ◽  
Vegetation Control ◽  
Competing Vegetation ◽  
Dominant Height ◽  
Stand Basal Area

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.

scholarly journals Modeling Response to Midrotation Nitrogen and Phosphorus Fertilization in Loblolly Pine Plantations

2000 ◽  
Vol 24 (4) ◽  
pp. 207-212 ◽  
Author(s):  
Ralph L. Amateis ◽  
Jiping Liu ◽  
Mark J. Ducey ◽  
H. Lee Allen
Keyword(s):  
Loblolly Pine ◽  
Basal Area ◽  
Site Index ◽  
Phosphorus Fertilization ◽  
Nitrogen And Phosphorus ◽  
Fertilizer Response ◽  
Nonlinear Regression Models ◽  
Dominant Height ◽  
Volume Response ◽  
Pinus Taeda L

Abstract Data from a fertilizer response study in loblolly pine (Pinus taeda L.) plantations at different sites in the southeastern United States were used to develop response models for dominant height and basal area following midrotation nitrogen (N) and phosphorus (P) fertilization. Nonlinear regression models developed from the data predict total cumulative response as a function of the interaction of N and P application rates, drainage class of the site, stand conditions when fertilized, and time since fertilization. Stand variables that were found to be significant predictors of response included site index, age, basal area, number of surviving trees, and dominant height at fertilization. Dominant height response was significantly greater on poorly drained sites than on other sites. Basal area response to P was significantly less on poorly drained sites and significantly greater on well drained sites. These models can be coupled with unfertilized baseline models to estimate volume response to midrotation fertilization. South. J. Appl. For. 24(4):207-212.

Growth of Loblolly Pine Stands After the First Five Years of Uneven-Aged Silviculture Using Single-Tree Selection

1994 ◽  
Vol 18 (3) ◽  
pp. 128-132 ◽  
Author(s):  
Paul A. Murphy ◽  
Michael G. Shelton
Keyword(s):  
Pinus Taeda ◽  
Loblolly Pine ◽  
Volume Growth ◽  
Basal Area ◽  
Site Index ◽  
Single Tree ◽  
Single Tree Selection ◽  
Pinus Taeda L ◽  
North Louisiana ◽  
Positive Effect

Abstract The effects of three levels of residual basal area (40, 60, and 80 ft2/ac), maximum dbh (12, 16, and 20 in.) and site index (< 81 ft, 81 to 90 ft, and >90 ft) on the growth of loblolly pine (Pinus taeda L.) stands after 5 yr of uneven-aged silviculture were determined from plots located in south Arkansas and north Louisiana. Designated levels of basal area and maximum dbh were achieved by harvesting; a q factor of 1.2 (using 1 in. dbh classes) was imposed on all plots as closely as possible. Stand-level models were developed for annual per acre net volume growth (merchantable cubic feet, sawtimber cubic feet, and sawtimber board feet, Doyle rule) and annual per acre survivor growth, ingrowth, and mortality components of basal area growth. Growth for all volume measures increased with an increase in basal area. Site index did not significantly affect merchantable cubic-foot growth but had a positive effect on sawtimber growth in both cubic feet and board feet, Doyle. Increases in maximum dbh decreased merchantable and sawtimber cubic-foot growth but increased growth for board-foot volume, Doyle. South. J. Appl. For. 18(3): 128-132.

Hardwood Eradication Improves Productivity of Thinned Loblolly Pine Stands

1984 ◽  
Vol 8 (4) ◽  
pp. 194-197 ◽  
Author(s):  
T. R. Clason
Keyword(s):  
Pinus Taeda ◽  
Loblolly Pine ◽  
Volume Growth ◽  
Growth And Yield ◽  
Detectable Effect ◽  
Herbaceous Vegetation ◽  
Vegetation Control ◽  
Pine Stands ◽  
Pinus Taeda L

Abstract A single hardwood eradication treatment in a 7-year-old loblolly pine (Pinus taeda L.) stand along with pine stocking control increased growth and yield over a 10-year period. Herbaceous vegetation control had no detectable effect at ages 12 and 17. Treated plots had smaller stems, which could be controlled more readily by fire, although the number of understory stems was similar for all treatments. Mean annual radial and merchantable volume growth on treated plots surpassed controls by 30%. Future stand values were enhanced by removing hardwood competition. Residual stand sawtimber volumes on the treated plots were twice that of the control.

scholarly journals Planted Loblolly Pine Survival and Growth Responses to Herbaceous Vegetation Control

1996 ◽  
Vol 20 (1) ◽  
pp. 53-57 ◽  
Author(s):  
Jimmie L. Yeiser ◽  
Richard A. Williams
Keyword(s):  
Loblolly Pine ◽  
Sandy Loam ◽  
First Year ◽  
Growth Responses ◽  
Herbaceous Vegetation ◽  
Vegetation Control ◽  
Growing Seasons ◽  
Pine Seedlings ◽  
Pinus Taeda L ◽  
Over The Top

Abstract Plots in 13 loblolly pine (Pinus taeda L.) plantations established on sandy or sandy-loam soils in SE Oklahoma and SW Arkansas received herbaceous vegetation control using hexazinone and sulfometuron methyl. Treatments consisted of a one-time herbicide application over-the-top of loblolly pine seedlings by one of three methods: spot, band, or broadcast. At the end of 1 and 5 growing seasons, data were collected for survival, height, and diameter growth and compared for seedlings in areas untreated and treated for herbaceous vegetation control. Only data corresponding to herbicide rates and application methods labeled for use today are included in data analysis. When compared with untreated checks, seedlings treated for herbaceous vegetation control exhibited significant increases in first-year survival at 11 sites and in height and groundline diameter (GLD) at 12 of the 13 test sites. At the end of 1 growing season, herbaceous vegetation control provided mean seedling increases of 16.7%, 0.4 ft, and 0.1 in. for survival, height, and GLD, respectively. After 5 growing seasons, advantages from herbaceous vegetation control had increased with significant differences existing in survival, height, and diameter at breast height (dbh) on 10 of 11 test sites, as 2 sites were lost to wildfire. Numerically, treatment differences had increased to 18.4%, 2.4 ft, and 0.6 in. for survival, height, and dbh, respectively. South. J. Appl. For. 20(1):53-57.

Spacing rectangularity effect on the growth of loblolly pine plantations

2002 ◽  
Vol 32 (8) ◽  
pp. 1451-1459 ◽  
Author(s):  
Mahadev Sharma ◽  
Harold E Burkhart ◽  
Ralph L Amateis
Keyword(s):  
Pinus Taeda ◽  
Loblolly Pine ◽  
Basal Area ◽  
Planting Density ◽  
Stand Development ◽  
Crown Width ◽  
Pine Trees ◽  
Tree Data ◽  
Initial Spacing ◽  
Pinus Taeda L

The effect of spacing rectangularity on tree growth and stand development was evaluated using tree data obtained annually from a loblolly pine (Pinus taeda L.) spacing trial monitored through age 16 years. In this trial, plots with an initial planting density of 2240 trees/ha occur at slightly and highly rectangular spacings. Spacings with rectangularities 3:4 and 1:3 were used to evaluate the rectangularity effect. Survival and the development of height, diameter, volume per hectare, and basal area per hectare of loblolly pine trees were not affected by rectangularity. Diameter and height distributions were found to be a function of age but not a function of the rectangularity of initial spacing. Crown width, however, was affected by rectangularity. The crown width was larger at larger row or column distance than at smaller row or column distance, but the ratio of crown widths between and within rows was not equal to the rectangularity of the original planting spacing.

scholarly journals Modeling Response to Thinning in Loblolly Pine Plantations

2000 ◽  
Vol 24 (1) ◽  
pp. 17-22 ◽  
Author(s):  
Ralph L. Amateis
Keyword(s):  
Loblolly Pine ◽  
Basal Area ◽  
Response Models ◽  
Thinning Intensity ◽  
Nonlinear Regression Models ◽  
Predictors Of Response ◽  
Cumulative Response ◽  
Before And After ◽  
Volume Response ◽  
Pinus Taeda L

Abstract Data from a thinning study established in loblolly pine (Pinus taeda L.) plantations at different locations in the southeastern United States were used to develop response models for basal area and survival following thinning. The nonlinear regression models predict total cumulative response as a function of stand and site conditions at time of thinning, thinning intensity, and elapsed time since thinning. Variables expressing thinning intensity that were significant predictors of response included before and after thinning basal areas and number of trees. The models suggest that initially after thinning, volume response declines briefly then gradually increases toward the unthinned control. Managers can use the equations presented here to evaluate the effect of alternative thinning regimes on stand development. The response equations can also be combined with baseline models for unthinned stands to predict basal area and number of trees following thinning. South. J. Appl. For. 24(1):17-22.

Growth response of loblolly pine, sweetgum, and water oak in a pine-hardwood density study

1999 ◽  
Vol 29 (7) ◽  
pp. 968-978 ◽  
Author(s):  
Glenn Glover ◽  
Harold Quicke
Keyword(s):  
Pinus Taeda ◽  
Loblolly Pine ◽  
Growth Response ◽  
Basal Area ◽  
Volume Index ◽  
Vegetation Control ◽  
Quercus Nigra ◽  
Pinus Taeda L ◽  
Water Oak ◽  
Density Study

A study was established with loblolly pine (Pinus taeda L.) planted at 1683 trees/ha competing with sweetgum (Liquidambar styraciflua L.), water oak (Quercus nigra L.), or loblolly pine at densities of 0, 1794, 2692, and 5382 trees/ha. The study is a split-split plot with three blocks. Main plots are the three competitor species; subplots are with or without 2 years of herbaceous vegetation control (HVC); and sub-subplots are competitor densities. The study was measured at 6 years after establishment. Pines in pure plots responded to HVC with a mean basal area gain of 1.8 m2/ha (13%). With HVC, basal area increased 2.7 m2/ha (70%) for sweetgum and 2.3 m2/ha (58%) for water oak. Pines in mixed plots did not respond, or responded negatively, to HVC. Pine height, basal area, volume index, and canopy projection were only slightly affected by sweetgum density above zero. Pine characteristics decreased as water oak density increased. Adding sweetgum or water oak to pine reduced total (pine + hardwood) volume index and basal area.

scholarly journals A Dynamic Stand Growth Model System for Loblolly Pine Responding to Mid-Rotation Treatments

Forests ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 556
Author(s):  
Mauricio Zapata-Cuartas ◽  
Bronson P. Bullock ◽  
Cristian R. Montes ◽  
Michael B. Kane
Keyword(s):  
Growth Model ◽  
Loblolly Pine ◽  
Basal Area ◽  
Model System ◽  
Growth And Yield ◽  
Site Quality ◽  
Response To Treatment ◽  
Plantation Management ◽  
Vegetation Control ◽  
Dominant Height

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.

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