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.

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.

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.

scholarly journals The Influence of Thinning on the Proportion of Peeler, Sawtimber, and Pulpwood Trees in Loblolly Pine Plantations

2005 ◽  
Vol 29 (3) ◽  
pp. 158-162 ◽  
Author(s):  
Ralph L. Amateis ◽  
Harold E. Burkhart
Keyword(s):  
Loblolly Pine ◽  
Significant Influence ◽  
Basal Area ◽  
Product Distribution ◽  
Pine Plantations ◽  
Thinning Intensity ◽  
Modeling Methods ◽  
Before And After ◽  
History Of

Abstract Data from a long-term, region-wide thinning study were used to examine the proportion of pulpwood, sawtimber, and peeler quality trees in unthinned, once-thinned, and twice-thinned plantations. Results suggest that the thinning treatments have had a significant influence on the product distribution in these stands over the 21-year history of the study. Proportional odds modeling methods were used to develop equations for predicting product proportions from dbh, the basal area before and after thinning (thinning intensity), and the number of thinnings imposed. South. J. Appl. For. 29(3):158–162.

scholarly journals Competition Effects on Growth and Crown Dimensions of Shortleaf and Loblolly Pine in Mature, Natural-Origin, Pine–Hardwood Mixtures of the Upper West Gulf Coastal Plain of Arkansas, USA: A Neighborhood Analysis

Forests ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 935
Author(s):  
Mohammad Bataineh ◽  
Ethan Childs
Keyword(s):  
Loblolly Pine ◽  
Species Abundance ◽  
Basal Area ◽  
Pinus Echinata ◽  
Shortleaf Pine ◽  
Species Identity ◽  
Linear Mixed Effects ◽  
Natural Origin ◽  
Pinus Taeda L ◽  
Crown Dimensions

The need for a comprehensive and mechanistic understanding of competition has never been more important as plants adapt to a changing environment and as forest management evolves to focus on maintaining and enhancing complexity. With the recent decline in shortleaf pine (Pinus echinata Mill.) land area, it is critical to determine the effects of competition on shortleaf pine and its performance against loblolly pine (Pinus taeda L.), the preferred planted replacement. We evaluate differences in shortleaf and loblolly pine 10 year mean basal area increment (BAI) and crown dimensions across a gradient of neighborhoods. Linear mixed-effects regression models were developed using BAI and several crown metrics as responses and crowding, competitor species abundance and identity, and initial size and species identity of focal tree as predictors. Crowding of focal trees negatively impacted BAI and crown size (p < 0.001, respectively). Although loblolly pine had three times higher BAI as compared to shortleaf pine within similar neighborhoods, BAI was variable, and the crowding effect did not differ between shortleaf and loblolly pine (p ranged from 0.51–0.99). Competitive impacts on focal trees did not differ by competitor identity (p ranged from 0.07–0.70). Distance-independent competition indices better explained the variation in BAI and horizontal crown metrics, while distance-dependent size ratios were more effective at evaluating vertical crown metrics. These findings highlight shortleaf pine competitive potential in mature, natural-origin stands and provide support for the restoration of pine–hardwood and hardwood–pine stratified mixtures as well as management of shortleaf pine at long rotations.

Thinned Loblolly Pine Stand Growth Improved by Early Hardwood Suppression

1991 ◽  
Vol 15 (1) ◽  
pp. 22-27
Author(s):  
Terry R. Clason
Keyword(s):  
Pinus Taeda ◽  
Loblolly Pine ◽  
Volume Growth ◽  
Basal Area ◽  
Growth Data ◽  
Stand Growth ◽  
Pinus Taeda L

Abstract A hardwood suppression treatment applied to a 7-year-old, loblolly pine (Pinus taeda L.) plantation enhanced projected productivity through a 35-year rotation that included three commercial thinnings. By age 22, growth data showed that hardwood removal treatments had larger pines and smaller hardwoods than check treatments. Fifteen-year pine basal area and merchantable volume growth on hardwood removal plots exceeded the check plots by 25 and 27%. Projected growth between ages 22 and 35 indicated that 28 years after early hardwood removal thinned plantation merchantable volume yields improved by 840 ft³ per acre. South. J. Appl. For. 15(1):22-27.

Eight-Year Performance of Loblolly Pine with Pisolithus Ectomycorrhizae on a Good-Quality Forest Site

1988 ◽  
Vol 12 (4) ◽  
pp. 275-280 ◽  
Author(s):  
Donald H. Marx ◽  
Charles E. Cordell ◽  
Alexander Clark
Keyword(s):  
Pinus Taeda ◽  
Loblolly Pine ◽  
Basal Area ◽  
Site Index ◽  
Forest Site ◽  
Water Deficits ◽  
Growing Seasons ◽  
Area Growth ◽  
Pinus Taeda L ◽  
Crown Closure

Abstract Loblolly pine (Pinus taeda L) seedlings with different initial amounts of Pisolithus tinctorius (Pt) ectomycorrhizae (Pt index 0, 27, 46, 68, or 88) were planted on a good-quality site (site index 90 ft at age 50) in southwest Georgia. After 8 years and crown closure, trees with Pt indices of 88 and 68 had significantly better survival and greater heights, diameters, volumes, and green weights per tree and per ac than nursery-run, control seedlings (Pt index 0). Volume and weight yields per ac were over 50% greater and volume and weight yields per tree were over 20% greater for trees in the Pt index 88 treatment than they were for control trees. A special statistical analysis indicated that average per ac volume was positively correlated with initial Pt index values larger than 58. Tree-ring analyses showed that trees with a Pt index of 88 had significantly greater annual basal area growth than controls during growing seasons with water deficits of 8 to 13 in. Annual growth did not differ when water deficits were greater or less than these amounts. After 8 years, Pt basidiocarps were present throughout the study site. Mycorrhizal treatment integrity may have been lost after 3 or 4 years. South. J. Appl. For. 12(4):275-280

scholarly journals A Growth and Yield Model Incorporating Hardwood Competition for Natural Loblolly Pine Stands in the Georgia Piedmont

1999 ◽  
Vol 23 (3) ◽  
pp. 179-185 ◽  
Author(s):  
Stacey W. Martin ◽  
Graham H. Brister
Keyword(s):  
Loblolly Pine ◽  
Basal Area ◽  
Growth And Yield ◽  
Parameter Estimates ◽  
Yield Model ◽  
Pinus Taeda L ◽  
Projection Equations ◽  
Georgia Piedmont ◽  
The Impact ◽  
Over Time

Abstract Using 5 yr remeasurement data from even-aged natural loblolly pine (Pinus taeda L.) stands in the Georgia Piedmont, a system of growth equations was developed to project pine yield over time that accounts for hardwood competition. In this system, the increase in the proportion of hardwood basal area over time is estimated, then the projected pine basal area and trees per acre are adjusted inversely to account for this increase. The parameter estimates for this system ensure compatibility between volume prediction and projection equations and the proportion of hardwood basal area, pine basal area, dominant height, and trees per acre projection equations. The whole-stand growth and yield system developed here coupled with published merchantable yield equations allow for the evaluation of the impact of hardwoods on future stand yield and product distributions. The results indicate that the impact of hardwood competition on pine yield is substantial and occurs mainly as a reduction in sawtimber volume. South. J. Appl. For. 16(3):179-185.

Fertilization of Established Southern Pine Stands: Effects of Single and Split Nitrogen Treatments

1993 ◽  
Vol 17 (3) ◽  
pp. 135-138 ◽  
Author(s):  
Eric J. Jokela ◽  
Stephen C. Stearns-Smith
Keyword(s):  
Loblolly Pine ◽  
Volume Growth ◽  
Basal Area ◽  
Pinus Elliottii ◽  
Growth Responses ◽  
Southern Pine ◽  
N Application ◽  
Pine Stands ◽  
Pinus Taeda L ◽  
Nitrogen Treatments

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.

Crown efficiency in a loblolly pine (Pinus taeda) spacing experiment

1998 ◽  
Vol 28 (9) ◽  
pp. 1344-1351 ◽  
Author(s):  
Hubert Sterba ◽  
Ralph L Amateis
Keyword(s):  
Pinus Taeda ◽  
Loblolly Pine ◽  
Basal Area ◽  
Tree Height ◽  
Projection Area ◽  
Individual Tree ◽  
Dominant Height ◽  
Crown Projection Area ◽  
Pinus Taeda L ◽  
Crown Closure

Crown efficiency was first defined by Assmann (1961. Waldertragskunde. BLV, München) as individual tree volume increment per unit of crown projection area. He hypothesized that within a given crown class, smaller crowns are more efficient because their ratio between crown surface and horizontal crown projection is higher. Data from a loblolly pine (Pinus taeda L.) spacing experiment were used to test if this hypothesis also holds in young loblolly pine stands and, if so, to determine if it explains the increment differences between spacings in the spacing experiment. Using individual tree height relative to plot dominant height to describe crown class, within-plot regression showed that crown efficiency decreased with crown size for trees below dominant height. This relationship was much less pronounced than indicated from Assmann's examples, although the crown surface to crown projection ratio behaved in the same way as Assmann had hypothesized. Crown efficiency as well as the crown surface to crown projection area ratio decreased with increasing density. Basal area increment per hectare increased until total crown closure approached 130% and then stayed constant. This major impact of total crown coverage brings into question the usefullness of crown efficiency as an indicator for unit area growth.

Color Aerial Photography for Assessing the Need for Fertilizers in Loblolly Pine Plantations

1988 ◽  
Vol 12 (4) ◽  
pp. 270-273 ◽  
Author(s):  
Charles R. Blinn ◽  
Al Lyons ◽  
Edward R. Buckner
Keyword(s):  
Pinus Taeda ◽  
Loblolly Pine ◽  
Aerial Photography ◽  
Basal Area ◽  
Site Index ◽  
Pine Plantations ◽  
Color Coding ◽  
Foliar N ◽  
Significant Relationships ◽  
Pinus Taeda L

Abstract Color aerial photography was used to assess crown color classes in loblolly pine (Pinus taeda L.) plantations. Three distinct Munsell color classes were delineated on the resulting photographs. Foliar N levels and, to a lesser degree, foliar K levels were directly related to color. Significant relationships between color and site index and color and basal area were shown. Application of color aerial photography, combined with Munsell color coding, could expedite land classification and also make possible more efficient use of fertilizers. South J. Appl. For. 12(4):270-273.

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