Recovery and Development of Understocked Loblolly-Shortleaf Pine Stands

1989 ◽  
Vol 13 (3) ◽  
pp. 132-139 ◽  
Author(s):  
James B. Baker

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.

1998 ◽  
Vol 22 (1) ◽  
pp. 47-52 ◽  
Author(s):  
James B. Baker ◽  
Michael G. Shelton

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.


1983 ◽  
Vol 7 (1) ◽  
pp. 45-50 ◽  
Author(s):  
Paul A. Murphy ◽  
Robert M. Farrar

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.


1998 ◽  
Vol 22 (1) ◽  
pp. 35-40 ◽  
Author(s):  
James B. Baker ◽  
Michael G. Shelton

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.


1991 ◽  
Vol 15 (1) ◽  
pp. 22-27
Author(s):  
Terry R. Clason

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.


2003 ◽  
Vol 27 (1) ◽  
pp. 18-29 ◽  
Author(s):  
Michael D. Cain ◽  
Michael G. Shelton

Abstract In southeastern Arkansas, pine growth was monitored for 19 yr after mechanically strip thinning a dense, naturally regenerated, even-aged stand of 6-yr-old loblolly pines (Pinus taeda L.) and shortleaf pines (P. echinata Mill.) that averaged 16,600 stems/ac. Prescribed winter burns were conducted biennially between ages 9 and 20 yr and at 24 yr. Commercial thinnings during the 17th and 23rd growing seasons left a residual stocking of either 85 ft2/ac or 200 crop trees/ac (75 ft2/ac) in merchantable-sized (> 3.5 in. dbh) pines on plots that were precommercially thinned and on plots that were not. Precommercial thinning enhanced pine growth in dbh and sawlog volume through 25 yr. Because of increased sawlog production, present net value averaged highest on plots that were precommercially thinned at age 6 then commercially thinned during the 17th yr to 200 crop trees/ac and during the 23rd yr to 75 ft2/ac. In the year following prescribed winter burns, both dbh growth and volume growth were reduced by about one-half when crown scorch was 75%. South. J. Appl. For. 27(1):18–29.


1998 ◽  
Vol 22 (1) ◽  
pp. 41-46 ◽  
Author(s):  
James B. Baker ◽  
Michael G. Shelton

Abstract Development of 86 intermediate and suppressed loblolly pine (Pinus taeda L.) trees, that had been recently released from overtopping pines and hardwoods, was monitored over a 15 yr period. The trees were growing in natural stands on good sites (site index = 90 ft at 50 yr) that had been recently cut to stocking levels ranging from 10 to 50%. At time of release, the trees averaged 26 yr in age, 4.8 in. in dbh, and 37 ft in height. The trees had averaged only 0.5 in. in dbh growth the 5 yr prior to release (0.1 in./yr). After 15 yr, the 77 surviving trees averaged 59 ft in height and 12.9 in. in dbh, increasing 21 ft in height and 8.1 in. in dbh. During the 15 yr period, crown dimensions of the trees increased markedly as well. On average, crown lengths increased 11 ft (from 16 to 27 ft); crown widths nearly tripled from 9 to 25 ft; and crown volumes increased 11 fold from 608 to 6,700 ft³. The majority of the trees had good form and would produce high-quality sawtimber. Satisfactory response to release was best predicted by initial dbh and live-crown ratio. Results of the study suggest that trees with at least a 20% live-crown ratio should satisfactorily respond to release even though they had developed in lower crown positions of fully stocked uneven-aged stands for 10 to 50 yr. Responding trees rapidly expanded their crowns and accelerated in height and diameter growth. South. J. Appl. For. 22(1):41-46.


1998 ◽  
Vol 22 (1) ◽  
pp. 53-59 ◽  
Author(s):  
James B. Baker ◽  
Michael G. Shelton

Abstract A 3- to 6-yr-old naturally regenerated even-aged loblolly pine (Pinus taeda L.) stand and a 5-yr-old loblolly pine plantation on good sites (SILob = 85 to 90 ft at 50 yr) were cut to density levels of 50, 90, 180, 270, and 360 seedlings and/or saplings/ac. Two pine release treatments (none and individual tree release with a herbicide) were applied to the natural stand, but were not imposed in the plantation because site preparation treatments were applied before planting. At 2, 5, and 10 yr after installation, plots were inventoried to determine: (1) the lowest threshold of seedling/sapling density that was feasible to manage, (2) the time required for poorly stocked seedling/sapling stands to reach an acceptable stocking level, and (3) whether release treatments would improve survival and growth of understocked, natural seedling/sapling stands. Results indicated that loblolly pine plantations on good sites having at least 180 trees/ac (30% stocking) reached an acceptable stocking level of 60% by age 10 and produced up to 1,500 ft³/ac (19 cd/ac) of merchantable volume by age 15. By this age, trees in plantations with 270 and 360 trees/ac displayed good form, but at densities of 180, 90, and 50 trees/ac the trees still retained large branches nearly to the ground. Natural stands having at least 180 trees/ac that were released from overtopping by hardwood at age 5 reached 60% stocking by age 15 but produced only 627 ft³/ac (8 cd/ac) of merchantable volume. When pines in the natural stand were not released, only plots with 360 trees/ac reached an acceptable 60% stocking level by age 15 but only produced 539 ft³/ac (7 cd/ac) of merchantable volume. The observed differences in recovery rates in the understocked pine stands principally reflected the levels of competing hardwoods. Results suggest that understocked, natural stands or plantations of pine seedlings/saplings with fewer than 180 trees/ac (less than 30% stocking), at age 5, should probably be liquidated and a new stand established unless the landowner is willing to sacrifice significant reductions in early volume production. South. J. Appl. For. 22(1)53-59.


1988 ◽  
Vol 12 (2) ◽  
pp. 107-114 ◽  
Author(s):  
James M. Guldin ◽  
James B. Baker

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


1982 ◽  
Vol 6 (2) ◽  
pp. 115-119 ◽  
Author(s):  
Paul A. Murphy ◽  
Robert M. Farrar

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.


Forests ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 935
Author(s):  
Mohammad Bataineh ◽  
Ethan Childs

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.


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