Yield Comparisons from Even-Aged and Uneven-Aged Loblolly-Shortleaf Pine Stands

Abstract Empirical yields for a 36-year management period are presented for seven long-term studies on similar sites in loblolly-shortleaf pine (Pinus taeda L.-P. echinata Mill.) stands on the upper southern coastal plain of southern Arkansas and northern Louisiana. Total merchantable cubic-foot yields are highest for conventionally managed even-aged plantations; sawtimber cubic-foot yields are highest for intensively managed even-aged plantations and intensively managed uneven-aged stands. However, uneven-aged stands have higher board-foot sawtimber yields than the most productive even-aged stands, particularly in comparisons using the Doyle log rule. It is hypothesized that the even-aged plantations have higher cubic-foot yields because they are more fully stocked with trees of merchantable size. Conversely, the uneven-aged stands have higher board-foot yields because of the greater proportion and continuous supply of sawtimber basal area, especially in stems of large size, which can be developed using the uneven-aged selection method. South J. Appl. For. 12(5):107-114

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Natural Loblolly and Shortleaf Pine Productivity Through 53 Years of Management under Four Reproduction Cutting Methods

Southern Journal of Applied Forestry ◽

10.1093/sjaf/25.1.7 ◽

2001 ◽

Vol 25 (1) ◽

pp. 7-16 ◽

Cited By ~ 7

Author(s):

Michael D. Cain ◽

Michael G. Shelton

Keyword(s):

Pinus Taeda ◽

Coastal Plain ◽

Total Production ◽

Shortleaf Pine ◽

Forest Landowners ◽

Advantages And Disadvantages ◽

Volume Production ◽

Pinus Taeda L ◽

Productive Method

Abstract A study was initiated in 1943 to evaluate the long-term productivity of loblolly (Pinus taeda L.) and shortleaf pines (P. echinata Mill.) when managed under four reproduction cutting methods—clearcut, heavy seedtree, diameter-limit, and selection—on the Upper Coastal Plain of southeastern Arkansas. Early volume production reflected retention of residual pines, and the clearcut was the least productive method through the first 36 yr. After 53 yr, there were no statistically significant (P = 0.07) differences among cutting methods in sawlog volume production, which averaged 3,800 ft3/ac. In terms of sawlog volume (bd ft/ac, Doyle scale), total production on clearcut, seedtree, and selection plots exceeded (P < 0.01) that on diameter-limit plots by 37%, but there were no differences in sawlog volume production among the other cutting methods. Results suggest that forest landowners should consider the advantages and disadvantages of each cutting method when planning their long-term objectives. South. J. Appl. For. 25(1):7–16.

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Basal Area and Diameter Distribution Models for Loblolly Pine Plantations with Hardwood Competition in the Piedmont and Upper Coastal Plain

Southern Journal of Applied Forestry ◽

10.1093/sjaf/16.2.93 ◽

1992 ◽

Vol 16 (2) ◽

pp. 93-98 ◽

Cited By ~ 7

Author(s):

Steven A. Knowe

Keyword(s):

Pinus Taeda ◽

Loblolly Pine ◽

Coastal Plain ◽

Basal Area ◽

Simulation Models ◽

Diameter Distribution ◽

Distribution Models ◽

Pinus Taeda L ◽

The Impact ◽

Volume Equations

Abstract Prediction equations were developed for basal area and percentiles of diameter distributions to account for the hardwood component in site-prepared, Piedmont and Upper Coastal Plain loblolly pine (Pinus taeda L.) plantations. Unlike existing stand-level simulation models that incorporate hardwood competition, the new equations resulted in constant total basal area regardless of the amount of hardwood competition and permitted the variance of the diameter distribution to increase with increasing proportion of hardwoods. The equations presented can be used with existing dominant height, survival, and volume equations as a tool for assessing the impact of hardwoods on loblolly pine yield. South. J. Appl. For. 16(2):93-98.

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Sawtimber Volume Predictions for Uneven-Aged Loblolly-Shortleaf Pine Stands on Average Sites

Southern Journal of Applied Forestry ◽

10.1093/sjaf/7.1.45 ◽

1983 ◽

Vol 7 (1) ◽

pp. 45-50 ◽

Cited By ~ 4

Author(s):

Paul A. Murphy ◽

Robert M. Farrar

Keyword(s):

Pinus Taeda ◽

Loblolly Pine ◽

Basal Area ◽

Site Index ◽

Selection System ◽

Pinus Echinata ◽

Shortleaf Pine ◽

Elapsed Time ◽

Pine Stands ◽

Pinus Taeda L

Abstract Equations are given to estimate current and projected sawtimber volumes and projected basal area of the sawtimber portion of uneven-aged loblolly-shortleaf (Pinus taeda L.-Pinus echinata Mill.) pine stands managed under the selection system. The independent variables are elapsed time, initial merchantable basal area, and the initial ratio of sawtimber basal area to merchantable basal area. The results should provide guidelines for the board-foot and cubic-foot production of sawtimber-sized trees in uneven-aged stands that occur on average sites (site index 90, loblolly pine) in the Coastal Plain.

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Rehabilitation of Understocked Loblolly-Shortleaf Pine Stands—I. Recently Cutover Natural Stands

Southern Journal of Applied Forestry ◽

10.1093/sjaf/22.1.35 ◽

1998 ◽

Vol 22 (1) ◽

pp. 35-40 ◽

Cited By ~ 6

Author(s):

James B. Baker ◽

Michael G. Shelton

Keyword(s):

Pinus Taeda ◽

Management Strategy ◽

Low Cost ◽

Basal Area ◽

Site Index ◽

Shortleaf Pine ◽

Considerable Cost ◽

Good Site ◽

Pinus Taeda L ◽

Natural Stands

Abstract Two loblolly-shortleaf pine (Pinus taeda L.-P. echinata Mill.) stands were cut to stocking levels of 10, 20, 30, 40, and 50% to simulate recently cutover, understocked, uneven-aged stands. Number of trees ranged from 38 per acre for 10% stocking to 213 per acre for 50% stocking; comparable total basal areas were 4 and 16 ft²/ac, respectively. One stand was on a good site (site index = 90 ft at age 50), the other on a medium site (site index = 75 ft at age 50). As a rehabilitation treatment, all hardwoods 1 in. groundline diameter and larger were injected with a herbicide. At 2, 5, 10, and 15 yr after treatment, the stands were inventoried to determine: (1) rate at which the understocked stands recovered, and (2) minimum stocking levels required for successful rehabilitation. During 15 yr of rehabilitation, the understocked stands changed dramatically, and because of rapid growth of residual pines, stocking levels, basal areas, and tree volumes increasedmarkedly. Stands having at least 20% residual stocking and 5 ft²/ac of pine basal area reached an acceptable stocking level of 60% (based on number and size of trees), or 45 ft²/ac of basal area within 15 yr. Stands at this minimum stocking threshold produced 4,600 bd ft(Doyle)/ac of sawtimber volume on the good site and 3,000 bd ft/ac of sawtimber volume on the medium site during the 15 yr period. The study indicates that recently cutover, or damaged, understocked stands with at least 20% to 30% stocking or 5 to 10 ft²/ac of pine basal area can be rehabilitated to produce respectable sawtimber volumes. This management strategy provides a low-cost alternative to establishing a new stand at considerable cost to the landowner. South. J. Appl. For. 22(1):35-40.

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Recovery and Development of Understocked Loblolly-Shortleaf Pine Stands

Southern Journal of Applied Forestry ◽

10.1093/sjaf/13.3.132 ◽

1989 ◽

Vol 13 (3) ◽

pp. 132-139 ◽

Cited By ~ 1

Author(s):

James B. Baker

Keyword(s):

Pinus Taeda ◽

Growth And Development ◽

Basal Area ◽

Shortleaf Pine ◽

Stand Growth ◽

Good Site ◽

Rehabilitation Period ◽

Pine Stands ◽

Pinus Taeda L ◽

Time Required

Abstract Plots in two uneven-aged loblolly-shortleaf pine (Pinus taeda L.-P. echinata Mill.) stands were cut back to stocking levels of approximately 10, 20, 30, 40, and 50% to simulate cutover, understocked stands. One stand was on a good site (SI = 90 ft at age 50), the other on a medium site(SI = 75 ft at age 50). As a rehabilitation treatment, all hardwoods 1-in. or larger in groundline diameter were injected with Tordon 101®. Two and 5 years later, the plots were reinventoried to determine stand growth and development. During the 5-year rehabilitation period the understockedstands changed dramatically, and because of the rapid growth of the pines left in the residual stands, stocking levels, basal areas, and tree volumes increased markedly. Average increases in stocking level, basal area, pulpwood, and sawlog volume were 40, 155, 160, and 355%, respectively,for the good site and 35, 110, 125, and 220% for the medium site. Projections of the time required for understocked stands to reach an acceptable stocking level of 60% (based on number and size of trees), or 45 ft² of basal area per acre, indicate that stands having at least 15 to 25%stocking, or 5 ft² of basal area per acre, can reach an acceptable stocking level in 15 years or less at a rehabilitation cost of $45 to $50 per acre. South. J. Appl. For. 13(3):132-139.

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Rehabilitation of Understocked Loblolly-Shortleaf Pine Stands—III. Natural Stands Cutover 15 Years Previously but Unmanaged

Southern Journal of Applied Forestry ◽

10.1093/sjaf/22.1.47 ◽

1998 ◽

Vol 22 (1) ◽

pp. 47-52 ◽

Cited By ~ 2

Author(s):

James B. Baker ◽

Michael G. Shelton

Keyword(s):

Pinus Taeda ◽

Basal Area ◽

Stand Development ◽

Shortleaf Pine ◽

Individual Tree ◽

Good Site ◽

Rehabilitation Period ◽

Mill Stand ◽

Pinus Taeda L ◽

Natural Stands

Abstract Plots in an unmanaged loblolly-shortleaf pine (Pinus taeda L.-P. echinata Mill.) stand that had been cutover 15 yr previously were established to represent five stocking levels: 10, 20, 30, 40, and 50%. The stand was on a good site (site indexLob = 90 ft at 50 yr) and had uneven-aged character. Two competition control treatments (none and individual tree release using herbicide) were also assigned. Three, five, and nine years later, the plots were reinventoried to determine: (1) the rate at which the understocked stands recovered, (2) the minimum stocking level required for successful rehabilitation, and (3) the effects of release on pine growth. The pine release treatment did not enhance stand development during the 9 yr rehabilitation period, primarily because only 18% of the pines (representing 5% of total pine basal area) were overtopped by hardwoods and were thus in need of release. However, results suggest that stands having an initial stocking of 20 to 30%, or a total basal area of 10 to 15 ft²/ac, can reach an acceptable stocking (levels of 60% for stocking, 45 ft²/ac for basal area, and 2,500 bd ft(Doyle)/ac for sawlog volume) within 15 yr or less. South. J. Appl. For. 22(1):47-52.

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Basal-area projection equations for thinned natural even-aged forest stands

Canadian Journal of Forest Research ◽

10.1139/x88-129 ◽

1988 ◽

Vol 18 (7) ◽

pp. 827-832 ◽

Cited By ~ 5

Author(s):

Paul A. Murphy ◽

Robert M. Farrar Jr.

Keyword(s):

Coastal Plain ◽

Basal Area ◽

Shortleaf Pine ◽

Gulf Coastal Plain ◽

The West ◽

General Technique ◽

Using Data ◽

Projection Equations ◽

Better Than

Several existing basal-area projection equations, including one with a thinning term, were compared by using data from a long-term thinning study in natural even-aged stands of loblolly (Pinustaeda L.) and shortleaf pine (Pinusechinata Mill.) in the West Gulf Coastal Plain. The model with the thinning term was no better than existing models with no thinning variable. These results prompted a search to improve the projection models that include thinning. A general technique for introducing a thinning variable into basal-area projection models was developed. This study found that the efficacy of adding a thinning term depends upon the accuracy requirements of the user.

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Interim Models for Basal Area and Volume Projection of Uneven-Aged Loblolly-Shortleaf Pine Stands

Southern Journal of Applied Forestry ◽

10.1093/sjaf/6.2.115 ◽

1982 ◽

Vol 6 (2) ◽

pp. 115-119 ◽

Cited By ~ 8

Author(s):

Paul A. Murphy ◽

Robert M. Farrar

Keyword(s):

Pinus Taeda ◽

Basal Area ◽

Selection System ◽

Pinus Echinata ◽

Shortleaf Pine ◽

Independent Variables ◽

Elapsed Time ◽

Volume Production ◽

Pinus Taeda L ◽

Area And Volume

Abstract Equations are presented for estimating current volume, projected basal area, and projected volume for stands of loblolly-shortleaf (Pinus taeda L.-Pinus echinata Mill.) pine managed under the selection system. The independent variables are initial stand basal area and elapsed time. The estimates should provide a guide to the cubic-foot volume production that might be expected from stands on average sites (site indices 80-90 ft.), medium basal areas (30 to 70 sq. ft.) and time periods of 10 years or less.

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