scholarly journals Influence of Different Thinning Treatments on Stand Resistance to Snow and Wind in Loblolly Pine (Pinus taeda L.) Coastal Plantations of Northern Iran

Forests ◽  
2020 ◽  
Vol 11 (10) ◽  
pp. 1034
Author(s):  
Rodolfo Picchio ◽  
Farzam Tavankar ◽  
Francesco Latterini ◽  
Meghdad Jourgholami ◽  
Behroz Karamdost Marian ◽  
...  
Keyword(s):  
Pinus Taeda ◽  
Loblolly Pine ◽  
Basal Area ◽  
Wind Damage ◽  
Middle Aged ◽  
Northern Iran ◽  
Crown Length ◽  
Wide Range ◽  
Snow Damage ◽  
Pinus Taeda L

Loblolly pine (Pinus taeda L.) is one of the main exotic conifer species that has been widely planted for the past fifty years for timber production in the coastal areas of northern Iran. Heavy snowfall and strong winds can cause much damage to these forests over a short time span of only a few years. This study was conducted to estimate snow and wind damage and analyze the role of stand thinning in their resistance to snow and wind. Amount and type of snow and wind damage were examined through systematic (80 m × 80 m) sample plots (each plot area of 625 m2) in nine different stands (2–10 plots in each stand) in terms of age, structure, and silviculture history in three replications for each stand in April and May 2020. Results showed that the amount of snow and wind damage had a wide range from 1.3% to 30.7%. Snow damage was more than three times that of wind. Snow and wind damage in the young stands were significantly more serious (p < 0.01) than in the middle-aged and old stands, and damage was significantly higher (p < 0.01) in the unthinned stands than in the thinned ones. Slenderness coefficient (Height/Diameter ratio, HD ratio) of trees resulted to be a good indicator in young and middle-aged stands, while crown form indices (relative crown length and relative crown width) were acceptable indicators in old stands for risk of snow and wind damage. Our results showed that the normal thinning (15% of basal area) decreased snow and wind damage in all the stands, while the heavy thinning (35% of basal area) reduced the snow damage, but it increased the wind one. It is possible to recommend high intensity thinning in young stands, normal thinning in middle-aged stands, and light thinning (15% of basal area) in old ones.

An Overcrowded Loblolly Pine Stand Thinned With Fire

1977 ◽  
Vol 1 (1) ◽  
pp. 24-26 ◽  
Author(s):  
W. Henry McNab
Keyword(s):  
Pinus Taeda ◽  
Loblolly Pine ◽  
Low Intensity ◽  
Young Stand ◽  
Wide Range ◽  
Number Of Stems ◽  
Pinus Taeda L

Abstract A low-intensity fire in a dense young stand of loblolly pine (Pinus taeda L.) in the Piedmont of central Georgia reduced the number of stems by 65 percent. No tree larger than four inches in diameter at the groundline was killed. Thus, low-intensity fires may be beneficial in precommercially thinning young loblolly pine, but the technique should be considered only for stands with a wide range of diameters.

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

Nondestructive estimation of Pinus taeda L. wood properties for samples from a wide range of sites in Georgia

2005 ◽  
Vol 35 (1) ◽  
pp. 85-92 ◽  
Author(s):  
P D Jones ◽  
L R Schimleck ◽  
G F Peter ◽  
R F Daniels ◽  
A Clark III
Keyword(s):  
Pinus Taeda ◽  
Loblolly Pine ◽  
Near Infrared ◽  
Microfibril Angle ◽  
Nir Spectroscopy ◽  
Wood Properties ◽  
Small Sample ◽  
Dry Density ◽  
Wide Range ◽  
Pinus Taeda L

Preliminary studies based on small sample sets show that near infrared (NIR) spectroscopy has the potential for rapidly estimating many important wood properties. However, if NIR is to be used operationally, then calibrations using several hundred samples from a wide variety of growing conditions need to be developed and their performance tested on samples from new populations. In this study, 120 Pinus taeda L. (loblolly pine) radial strips (cut from increment cores) representing 15 different sites from three physiographic regions in Georgia (USA) were characterized in terms of air-dry density, microfibril angle (MFA), and stiffness. NIR spectra were collected in 10-mm increments from the radial longitudinal surface of each strip and split into calibration (nine sites, 729 spectra) and prediction sets (six sites, 225 spectra). Calibrations were developed using untreated and mathematically treated (first and second derivative and multiplicative scatter correction) spectra. Strong correlations were obtained for all properties, the strongest R2 values being 0.83 (density), 0.90 (MFA), and 0.93 (stiffness). When applied to the test set, good relationships were obtained (Rp2 ranged from 0.80 to 0.90), but the accuracy of predictions varied depending on math treatment. The addition of a small number of cores from the prediction set (one core per new site) to the calibration set improved the accuracy of predictions and importantly minimized the differences obtained with the various math treatments. These results suggest that density, MFA, and stiffness can be estimated by NIR with sufficient accuracy to be used in operational settings.

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.

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

1992 ◽  
Vol 16 (2) ◽  
pp. 93-98 ◽  
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.

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

1983 ◽  
Vol 7 (1) ◽  
pp. 45-50 ◽  
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.

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.

scholarly journals Stand Density Index for Loblolly Pine Plantations in North Louisiana

1996 ◽  
Vol 20 (2) ◽  
pp. 110-113 ◽  
Author(s):  
Roger A. Williams
Keyword(s):  
Pinus Taeda ◽  
Loblolly Pine ◽  
Basal Area ◽  
Stand Density ◽  
Pine Plantations ◽  
Density Index ◽  
Pinus Taeda L ◽  
Stand Density Index ◽  
North Louisiana

Abstract Stand Density Index (SDI) equations and diagrams were developed and presented for loblolly pine (Pinus taeda L.) plantations in north Louisiana. Two different SDI diagrams are presented—one that utilizes the number of trees per acre and average stand diameter, and a second that uses the number of trees per acre and the basal (ft²) per acre. Basal area is presented as a second alternative to average stand diameter since many practicing foresters commonly use basal area for density management. South. J. Appl. For. 20(2):110-113.

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