bluuebunny/crossref_metadata_2025 huggingface dataset:
Rehabilitation of Understocked Loblolly-Shortleaf Pine Stands—IV. Natural and Planted Seedling/Sapling Stands
Authors: Baker James B. , Shelton Michael G.
Published: August 2019

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.
The Role of Assistance Foresters in Nonindustrial Private Forest Management: Alabama Landowners' Perspectives
Authors: Zhang Daowei , Warren Sarah , Bailey Conner
Published: August 2019

Nonindustrial private forest landowners in Alabama were surveyed and assistance foresters' involvement in their management activities documented. Overall, assistance foresters have participated in some 58% of all forest management activities. Consulting foresters account for 45 to 50% of those activities involving assistance foresters. Public foresters have more small and low income landowners as their clients, and consulting and industry foresters assist more medium and large landowners. The perception of all assistance foresters by the landowners is positive, and reputation is a key to acquire new clients. Respondents also believe that the number of public foresters should stay roughly the same or be increased, and they are evenly divided about paying a fee for services provided by public foresters. South. J. Appl. For. 22(2):101-105.
Immature Loblolly Pine Growth and Biomass Accumulation: Correlations with Seedlings Initial First-Order Lateral Roots
Authors: Kormanik Paul P. , Sung Shi-Jean S. , Zarnoch Stanley J.
Published: August 2019

Five to seven years after being graded by first-order lateral root (FOLR) numbers and outplanted, loblolly pine (Pinus taeda L.) seedlings were excavated using a commercial tree spade and root systems re-evaluated. Current competitive position of trees was related to initial FOLR numbers of 1-0 seedlings. Current FOLR numbers were comparable among tree size classes, but root diameters where the spade severed the root were different. The dominant and codominant individuals had much larger FOLR cross sectional area at the severed point. The larger diameter laterals allow exploration of larger soil volume since they extended greater distances from the tree. Root biomass allometric equations were developed from excavating 175 individuals in 3 separate plantations. Root biomass was readily predicted based on either stem diameter breast height squared (D²H), or total aboveground biomass. Approximately 75% of standing tree biomass was aboveground and 25% belowground for all initial root grades, current crown classes, and sites. Subsoil compaction layers appeared to have a major impact on tree development at any specific location within a plantation. Compaction layers affected heights and diameters but not root/top ratios or the relative competition position based on initial FOLR numbers. These compaction layers resulted in plate-like taproots that suggested further root penetration was unlikely. South. J. Appl. For. 22(2):117-123.
Prediction and Error of Baldcypress Stem Volume from Stump Diameter
Authors: Parresol Bernard R.
Published: August 2019

The need to estimate the volume of removals occurs for many reasons, such as in trespass cases, severance tax reports, and post-harvest assessments. A logarithmic model is presented for prediction of baldcypress total stem cubic foot volume using stump diameter as the independent variable. Because the error of prediction is as important as the volume estimate, I demonstrate construction and use of simple and joint confidence intervals about the mean and individual predictions. For completeness, I address prediction and error from inventory estimates of removals. South. J. Appl. For. 22(2):69-73.
Use of Forested Habitat by Breeding Birds in the Gulf Coastal Plain
Authors: Hill Geoffrey E.
Published: August 2019

I compared birds present during the breeding season in four forest types in the Conecuh National Forest located on the Gulf Coastal Plain in Alabama: (1) longleaf pine (Pinus palustris) that had been subject to several recent burns, (2) longleaf pine that had been subject to few or no recent burns, (3) planted slash pine (P. elliottii), and (4) various forested wetland habitats ranging from stream-side riparian habitat to cypress (Taxodium distichum) ponds. I found significantly higher total individuals and significantly higher bird species richness in the two natural forest types—burned longleaf pine and riparian habitats—than either unburned longleaf or slash pine. To maintain greatest diversity and abundance of birds, managers of forests on the Gulf Coastal Plain should (1)preserve wetland habitat, (2) not convert stands of longleaf pine to stands of slash pine, and (3) regularly burn longleaf pine stands. South. J. Appl. For. 22(3):133-137.
Prescribed Fire Effects on Advanced Regeneration in Mixed Hardwood Stands
Authors: Barnes T.A. , Van Lear D.H.
Published: August 2019

Fire treatments were initiated in 1990 to evaluate effects of low-intensity prescribed fires on composition and structure of the advanced regeneration pool under mature mixed-hardwood stands on upland sites in the Piedmont of South Carolina. One spring burn was as effective as three winter burns in reducing midstory density, considered a prerequisite for subsequent development of oak (Quercus spp.) advanced regeneration. Burning increased the number of oak rootstocks, reduced the relative position of competing species, and increased root-to-shoot ratios of oak stems in the regeneration layer. These favorable effects of fire on oak regeneration outweigh the removal of small, poorly formed oak stems from the midstory/understory strata during burning. Prescribed burning in hardwood forests may solve some of the current oak regeneration problems, especially on better upland sites in the South. South. J. Appl. For. 22(3):138-142.
Economics of Site Preparation and Release Treatments Using Herbicides in Central Georgia
Authors: Busby Rodney L. , Miller James H. , Edwards M. Boyd
Published: August 2019

Land expectation values (LEV) of site preparation and release treatments using herbicides in central Georgia are calculated and compared. Loblolly pine growth and hardwood competition levels were measured at age 6 for the site preparation treatments and age 8 for the release treatments. These measurements were projected to final harvest using the North Carolina State University growth and yield simulator. On six directly comparable sites, site preparation improved land expectation values more than release. When the most profitable treatments on each site were compared, site preparation LEVs (after tax) were more than twice as profitable as release ($403 vs. $188/ac). Velpar L¹ and Pronone 10G herbicide treatments increased the land expectation value most for site preparation. Arsenal AC and Velpar L provided the highest returns among the herbicides tested for release. South. J. Appl. For. 22(3):156-162.
Successful Reforestation of South Carolina Sandhills is not influenced by Seedling Inoculation with Pisolithus tinctorius in the Nursery
Authors: Cram Michelle M. , Mexal John G. , Souter Ray
Published: August 2019

Longleaf (Pinus palustris) and loblolly pine (P. taeda) nursery beds were treated with either vegetative inoculum of Pisolithus tinctorius (Pt) or allowed to become inoculated with natural ectomycorrhizae (NI) from 1987 to 1991. The resulting Pt and NI seedlings were outplanted on 2 sites per year (1988-1992) for a total of 10 demonstration plantings on the Savannah River Site (SRS), South Carolina. After 4 yr (5 yr for Site 5) the presence of Pt on bareroot longleaf pine at the time of planting did not improve seedling diameter or height growth. Longleaf pine survival was increased with the presence of Pt only on one site, while NI seedlings had greater survival on five sites and greater growth on two sites. The presence of Pt on the containerized longleaf pine had no effect on survival or diameter growth after 4 yr. Inoculation of bareroot loblolly pine with Pt resulted in larger diameter seedlings at the time of planting for four of eight sites. However, these differences in diameter were not maintained in three of the sites after 4 yr. The use of Pt as an artificial inoculant of bareroot longleaf and loblolly pine seedlings does not increase survival or growth response of reforestation plantings on the sandhills of South Carolina after 4 (5) yr. South. J. Appl. For. 23(1):46-52.
White-Tailed Deer Browse Preferences in a Southern Bottomland Hardwood Forest
Authors: Castleberry Steven B. , Ford W. Mark , Miller Karl V. , Smith Winston P.
Published: August 2019

We examined spring and summer use of woody browse by white-tailed deer (Odocoileus virginianus) in forest gaps created by group selection timber harvest in a South Carolina bottomland hardwood forest during 1995 and 1996. Percent available twigs browsed, relative abundance, and relative use were calculated for each species with more than 50 twigs sampled. We used chi-square analysis to rate species as preferred, proportional, or low use. Total percent browsed was low in both years (2.5% in 1995; 3.0% in 1996). In 1995, 6 species were rated as high use, 4 species as proportional use, and 10 species as low use. In 1996, 6 species were rated as high use, 7 as proportional use, and 9 as low use. Species ratings generally were in agreement with other food habits studies in the Southeast. Preferred browse species included red maple (Acer rubrum), winged elm (Ulmus alata), greenbrier (Smilax spp.), and black willow (Salix nigra). The low rates of browsing probably were due to low use of the study area by deer during the growing season. Deer browsing likely had little impact on regeneration of most species in this bottomland hardwood forest. South. J. Appl. For. 23(2):78-82.
Effects of Pine and Hardwood Basal Areas After Uneven-Aged Silvicultural Treatments on Wildlife Habitat
Authors: Miller Darren A. , Leopold Bruce D. , Conner L. Mike , Shelton Michael G.
Published: August 2019

Uneven-aged management (UEAM) is becoming increasingly popular in the southeastern United States. However, effects of UEAM on wildlife habitat have not been adequately documented. We examined response of habitat within stands of varying levels of pine and hardwood basal area under an uneven-aged management regime in southern Mississippi. Summer and winter trends in understory biomass were similar across treatments. Time since disturbance influenced plant productivity. Stands with lower basal areas tended to have higher browse production, denser and higher vertical habitat structure, more woody, vine, and fern biomass, greater total biomass, and higher plant species diversity and richness. Pine basal area had little influence on browse production relative to effects of hardwood basal area. Although stands with higher basal area had less biomass, a higher proportion of biomass was composed of preferred browse. We recommend that forest managers create stands of varying levels of pine and hardwood basal areas to provide for diverse needs of many wildlife species. South. J. Appl. For. 23(3):151-157.
Effects of Thinning on Development of Southern Pine Beetle Infestations in Old Growth Stands
Authors: Turchin Peter , Davidson James , Hayes Jane Leslie
Published: August 2019

A study was conducted to quantify the relationship between southern pine beetle infestation growth and the intertree spacing in old growth pine stands. The problem with extrapolating the results of previous studies to old growth stands is that it is unclear whether the same mechanism will operate in stands of older trees characterized by double the diameter (20-25 cm vs. 40-60 cm). In this study we focused on experimentally answering the question of how three levels of thinning (resulting in different average intertree distances) affect the rate of SPB infestation growth in mature loblolly pine stands, over 60 yr old and over 40 cm average dbh. We also included a hardwood removal treatment. Both intermediate and severe thinning had a strong negative effect on the rate of infestation growth. The effects of intermediate and severe thinning were similar; there was no statistically detectable difference between these two treatments. Hardwood removal appeared to decrease infestation growth rate compared to no thinning, but this effect was not statistically significant. South. J. Appl. For. 23(4):193-196.
Which Trees and Stands are attacked by the Southern Pine Beetle?
Authors: Zhang Yujia , Zeide Boris
Published: August 2019

An analysis of long-term observations from loblolly pine (Pinus taeda L.) plantations showed that the southern pine beetle, SPB (Dendroctonus frontalis Zimmermann), kills a larger proportion of trees in dense stands. The presence of hardwood species diminishes damage, probably by hindering the dispersal of the SPB. It was also found that, in a given stand, mortality increases with tree size. On the other hand, the degree of damage was not related to age or mean diameter. For our plots, the annual probability that a loblolly pine tree would be killed by the beetle was 4.59 x 10-4. In the SPB infested stands, this probability increased 39 times (1.81 x 10-2. More precise estimates can be made using a prediction model driven by stand densities of pines and hardwoods, and the relative diameter of individual trees. South. J. Appl. For. 23(4):217-223.
An Individual-Tree Growth and Yield Prediction System for Uneven-Aged Shortleaf Pine Stands
Authors: Huebschmann Michael M. , Gering Lawrence R. , Lynch Thomas B. , Bitoki Onesphore , Murphy Paul A.
Published: August 2019

A system of equations modeling the growth and development of uneven-aged shortleaf pine (Pinus echinata Mill.) stands is described. The prediction system consists of two main components: (1) a distance-independent, individual-tree simulator containing equations that forecast ingrowth, basal-area growth, probability of survival, total and merchantable heights, and total and merchantable volumes and weights of shortleaf pine trees; and (2) stand-level equations that predict hardwood ingrowth, basal-area growth, and mortality. These equations were combined into a computer simulation program that forecasts future states of uneven-aged shortleaf pine stands. Based on comparisons of observed and predicted stand conditions in shortleaf pine permanent forest inventory plots and examination of the growth patterns of hypothetical stands, the simulator makes acceptable forecasts of stand attributes. South. J. Appl. For. 24(2):112-120.
A Survey of the Preservative Treated Wood Market in Oklahoma
Authors: King Stephen A. , Lewis David K.
Published: August 2019

Retail lumberyards in Oklahoma were surveyed concerning their trade in treated wood products. Results indicate that an estimated producer price value of $39.3 million of treated dimension lumber, landscape timbers, fenceposts, poles, and plywood were sold by retail lumberyards in Oklahoma during 1996. Retail lumberyard managers report that farmers and ranchers are the most important consumer segment for treated wood product sales. Retailers also report that straightness, general appearance, and preservative retention level are the most important attributes that consumers desire in preservative treated wood products. South. J. Appl. For. 24(2):70-76.
Response of Loblolly Pine Plantations to Late-Rotation Fertilization and Herbicide Applications in North Louisiana
Authors: Williams Roger A. , Farrish Kenneth W.
Published: August 2019

Late-rotation fertilization was studied over a 6 yr period in loblolly pine (Pinus taeda L.) plantations in north Louisiana. Fertilizer (150 lb/ac of nitrogen and 50 lb/ac of phosphorus) and herbicide (hexazinone, 2.5 lb ai/ac) were applied to five loblolly pine plantations in the 25-yr-old age class (25-26 yr), and five plantations in the 30-yr-old age class (30-32 yr). The study was established as a randomized block design with three blocks in each plantation. Three treatments studied were fertilizer (F), fertilizer+herbicide (FH), and herbicide (H), which were compared to a control. Diameter and volume growth responded significantly to treatments F and FH in both age classes. A greater per-tree response occurred in the 25-yr-old age class as a result of the additive effect of recent thinnings. The use of herbicide in treatments FH and H did not cause a significant increase in growth response. The growth response in treatment FH was not significantly different from the response in treatment F, nor was the growth response in treatment H significantly different from the control. In the 25-yr-old age class the response to fertilization (treatments F and FH) was allocated primarily to the larger trees. Treatments F and FH increased total volume growth (lb) by 48 and 55 ft3/ac/yr, respectively, over control plots while treatment H increased growth by 15 ft3/ac/yr. In the 30-yr-old age class, the response was distributed more evenly among all diameter classes. Treatments F and FH increased total volume growth on average of 58 and 60 ft³/ac/yr, respectively, over control plots while treatment H increased growth by 17 ft3/ac/yr. An economic analysis was performed using discount rates of 8% and 12%, and current prices and costs at the time of the study. Rates of return ranged from 29.6 to 38.8% under various economic scenarios (discount rates, prices and costs) in the 25-yr-old age class. The net present value equivalent to an annual income (EAI) gain for each of the 6 yr of the study ranged from $34.07-$60.54/ac/yr. These same economic scenarios produced rates of return of 23.3 to 31.9% in the 30-yr-old age class, with an EAI range of $18.98-$40.03/ac/yr. South. J. Appl. For. 24(3):166-175.
Loblolly Pine—Pushing the Limits of Growth
Authors: Borders Bruce E. , Bailey Robert L.
Published: August 2019

With mean annual increments up to 5.4 cords/ac/yr, six loblolly pine (Pinus taeda L.) research sites in Georgia produced yields on par with other results from intensively managed loblolly plantations around the world. Cultural treatments in the Georgia study include complete control of vegetation other than the planted pines with multiple applications of herbicide, annual fertilization, the combination of complete vegetation control and annual fertilization, and an intensive mechanical site preparation treatment. Complete vegetation control resulted in higher yield production at ages 10 to 12 yr than the intensive mechanical treatment at all locations. This regime also resulted in higher yield production than the annual fertilization treatment at four of six locations. Volume mean annual increment for 10- to 12-yr-old plantations with the combination treatment of complete vegetation control and annual fertilization ranged from 325 to 490 ft3/ac, growth rates comparable to those obtained at other high biomass production areas throughout the world. Our economic evaluation based on these results shows that 8 to 12% real rates of return are feasible from investments in intensive loblolly pine plantations in the southeastern United States. South. J. Appl. For. 25(2):69–74.
Vegetation Cover Response and Second-Year Loblolly and Slash Pine Response Following Bedding and Pre- and Post-Plant Herbicide Applications in Florida
Authors: Lauer Dwight K. , Zutter Bruce R.
Published: August 2019

Site preparation treatments of early single bed (EB), late single bed (LB), double bed (DB), EB + banded pre-plant herbicide (PP), and EB + broadcast pre-plant herbicide (BPP) were applied to four locations in Florida. Three of the four locations included these treatments crossed with a first-year post-plant herbicide application to control herbaceous vegetation(HC). Second-year pine heights evaluated at two slash pine (P. elliottii Engelm.) locations and one loblolly pine (P. taeda L.) location averaged taller (4.6 vs. 3.5 ft) following double-pass (DB, PP, BPP) than single-pass (EB, LB) treatments, taller (4.9 vs. 4.0 ft) for pre-plant herbicide (PP, BPP) than DB, but did not differ between PP and BPP. There were no significant interactions between site preparation and HC with HC, increasing second-year pine height by 0.5 ft. Pine height was greater for pre-plant herbicide treatments than for DB treatments because pre-plant herbicide treatments provided better control of competing vegetation.

Vegetation control differed among treatments. DB improved control of woody shrubs over single bedding alone, but increased herbaceous cover in the first growing season. The increase in herbaceous cover following DB accounts for the relatively small gain in second-year pine height (0.2 ft) for DB compared to LB. Pre-plant herbicide treatments following early bedding improved control of both woody shrubs and first-year herbaceous vegetation. Pre-plant herbicide treatments also shifted the composition of herbaceous vegetation towards less competitive species. HC improved control of herbaceous plants, and lowest first-year herbaceous cover was achieved with the combination of HC with pre-plant herbicide treatments. South. J. Appl. For. 25(2):75–83.
Forestry's Third Revolution: Integrating Biotechnology into Pinus taeda L. Breeding Programs
Authors: Williams Claire G. , Byram Thomas D.
Published: August 2019

The Third Revolution—the application of molecular biology to plant improvement—is providing biotechnology for Pinus taeda breeding programs in the southern United States. To harness commercial value, forest biotechnology must be integrated with pine breeding. Overlaying an agriculture biotechnology template on any aspect of forestry ignores key historical, economic and biological factors unique to pine breeding programs and even to biotechnology applications. Understanding differences between forestry and agriculture will aid policy decisions about the use of genetically enhanced pines and identify numerous leverage points for directing forest biotechnology research toward commercial advantage. Integrating biotechnology into a P. taeda breeding program is illustrated using a case study approach. A molecular marker system is proposed for improving the selection efficacy of a pine breeding program. South. J. Appl. For. 25(3):116–121.
Twelve-Year Results of a Loblolly Pine Site Preparation Study in the Piedmont and Upper Coastal Plain of South Carolina, Georgia, and Alabama
Authors: Martin Stacey W. , Shiver Barry D.
Published: August 2019

A designed experimental study was installed at 25 separate locations in the Piedmont and Upper Coastal Plain regions of South Carolina, Georgia, and Alabama with the objective of evaluating the effects of different site preparation treatments, both chemical and mechanical, on growth and yield of cutover site-prepared loblolly pine (Pinus taeda L.) plantations. The following six site preparation treatments were included: (1) burn, (2) chop and burn, (3) shear, pile and disk, (4) chop, herbicide and burn, (5) herbicide and burn, and (6) herbicide, burn and complete vegetation control. The herbicide, burn and complete vegetation control treatment significantly increased mean dbh, mean height, stand basal area, and total and merchantable volume compared to all other treatments. The burn-only treatment consistently ranked worst compared to all other treatments. There were significant differences in mean dbh, mean height, stand basal area, and total and merchantable volume between: (1) the herbicide and burn, which is an operational chemical treatment, and (2) the average of the chop and burn treatment and the shear, pile and disk treatment, which are operational mechanical treatments. In all cases the operational chemical treatment performed significantly better than the average of the two operational mechanical treatments. Average 12-yr-old merchantable volumes (ft3/ac) across all locations by treatment were: burn (846), chop and burn (1,445), shear, pile and disk (1,740), chop, herbicide and burn (1,669), herbicide and burn (1,919), and herbicide, burn and complete vegetation control (2,546). There were no apparent trends in percent fusiform infection levels across site preparation treatment intensity levels. South. J. Appl. For. 26(1):32–36.
Impacts of Rotation Age Changes on Growth/Removals Ratios
Authors: Prisley Stephen P. , Malmquist Andrew J.
Published: August 2019

When forest managers and policymakers wish to assess the ability of a given forest resource to support a sustainable level of timber harvests, they frequently use growth/removals ratios (G/R) developed from forest inventory data. Recently published inventory data for forests of the southern United States have documented numerous states in which softwood harvests exceed softwood growth, raising concern over the sustainability of this critical resource. At the same time, forest managers in the South have been investing in a wide range of practices that have dramatically increased the growth rates for softwood plantations. As these growth increases are verified in the field, forest managers respond accordingly with adjustments to management regimes, including shortening of rotation lengths. This, in turn, means that the area of forest harvested annually must increase in a given forest estate to approach a regulated forest condition.

The Timber Inventory, Growth, and Removals model (TIGR) is a spreadsheet model developed to evaluate the impact of shortening rotation length on the growth/removals ratios for managed forests. The model demonstrates that a temporary imbalance of removals over growth results when the rotation age is shortened. Hence, managers and policymakers should use caution when making inferences or public claims about sustainable harvest levels from growth/removals ratios alone. If the public has been convinced that G/R ratios greater than 1.0 imply sustainable harvests, then difficult explanations will be required when the G/R ratio drops below 1.0. South. J. Appl. For. 26(2):72–77.
Using Simple Marginal Analysis and Density Management Diagrams for Prescribing Density Management
Authors: Dean Thomas J. , Chang S.Joseph
Published: August 2019

This article presents a procedure to produce management regimes that not only maximize land value but also reflect stand development with simple marginal analyses of the accumulation and control of growing stock. An upper limit of growing stock is determined by translating management objectives into a future desired structure, and with this value as a guide for thinning age, marginal analysis is used to determine the planting density and the residual basal area after thinning. The procedure is demonstrated for a hypothetical loblolly pine plantation growing on land with a site index of 65 ft at 25 yr. The effects of various interest rates for a fixed rotation length and various rotation lengths for a fixed interest rate on initial planting density and residual growing stock after low thinning are analyzed. Optimal planting density decreased with increasing interest rate and rotation length. Thinning ages increased as initial planting density decreased, which caused optimal residual growing stock to increase with increasing interest rate and rotation age. According to this study, maximum land value is achieved when the growing stock limits are set to approximately the lower limit of full-site occupancy and the threshold of self-thinning. In terms of relative density, the ideal limits in growing stock for maximizing land value identified in this study are 35 and 55% of maximum SDI. South. J. Appl. For. 26(2):85–92.
Effects of Selective Availability on GPS Positioning Accuracy
Authors: Liu C.J.
Published: August 2019

Deactivation of selective availability (SA) is expected to provide improvement in Global Positioning System (GPS) accuracy, and recent reports showed such improvements were realized immediately. However, most forestry GPS observations are made in subcanopy environments in which a GPS receiver's antenna can only receive GPS signals from a small region of the sky due to obstructions. Consequently, the satellite geometry will be poor, and position accuracy will suffer. Thus, there is a need to understand the impact of SA removal on positioning accuracy in high-PDOP subcanopy observations. This study found that it is difficult to approach the destination when GPS navigation is adversely influenced by SA accuracy degradation. When GPS positioning is performed after SA deactivation, a GPS observer can walk directly to the intended destination under thick tree canopies. Results also indicated that the horizontal accuracy is 73.3 m at the 95% probability level in the SA-degraded data set and 8.3 m in the SA-free data set. Further data analysis indicated that HDOPs (Langley 1999) recorded in the SA-on and the SA-off periods are not statistically significantly different. This suggests that a major portion of the difference in horizontal accuracies between SA-degraded and SA-free GPS observations can be attributed to difficulties in approaching the destination when SA is active. South. J. Appl. For. 26(3):140–145.
I. Early Loblolly Pine Stand Response to Tillage on the Piedmont and Upper Coastal Plain of Georgia: Mortality, Stand Uniformity, and Second and Third Year Growth
Authors: Will R.E. , Wheeler M.J. , Markewitz D. , Jacobson M.A. , Shirley A.M.
Published: August 2019

The effects of machine planting, disking, bedding, and bedding + subsoiling on growth of loblolly pine (Pinus taeda L.) were assessed after two and three growing seasons for seven contrasting sites on the Piedmont and Upper Coastal Plain of Georgia. Heights and groundline diameters of half the trees (50 trees) per plot, percent mortality, individual tree volume index (D2H), stand uniformity, and per hectare volume index were compared across sites and treatments. Average tree size of the treatments were ranked (from largest to smallest) bed, bed + subsoil, disk, machine, and no-till. At the end of the third growing season, the trees in the bed only treatment had a mean height, groundline diameter, and volume index of 2.3 m ± 0.06 SE, 59 mm ± 1.7 SE, and 0.0094 m3 ± 0.00066 SE, respectively. The trees of the no-till treatment had a mean height, groundline diameter, and volume index of 2.1 m ± 0.07 SE, 50 mm ± 1.6 SE, and 0.0063 3 ± 0.00056 SE, respectively. Overall, the disk, bed, and bed + subsoil treatment plots had significantly greater absolute volume growth during the third growing season than the no-till and machine plots. Most of the tree mortality within all treatments occurred during the first growing season with the disk treatment having the least mortality (13.6%) and the no-till treatment the most (24.9%). Stand height and diameter uniformity, examined using the within plot coefficient of variation, was not significantly different among treatments. Per hectare volume index was significantly greater for the bed (7.0 m3/ha) and bed + subsoil treatments (7.1 m3/ha) than for the no-till (4.5 m3/ha) and machine (5.2 m3/ha) treatments. Significant differences occurred between sites for tree size parameters, ranging between 2.7 m mean height and 64 mm mean groundline diameter for a site on a Cowarts soil series to 1.8 m mean height and 45 mm mean groundline diameter for trees growing on a Pacolet soil series. Significant interactions between tillage treatments and sites occurred for some tree size parameters at age 2, but not age 3, and for average plot mortality rate. The results of this study indicate that some early gains in tree growth can be achieved through soil tillage on upland sites. Bedding provided the most consistent, positive response, but adding subsoiling to bedding provided no benefit. Overall, the gains were relatively small and site dependent. Tillage on these Piedmont and Upper Coastal Plain soils should best be considered as part of a complete management program that includes to weed control and fertilization. South. J. Appl. For. 26(4):181–189.
An Evaluation of Dazomet Incorporation Methods on Soilborne Organisms and Pine Seedling Production in Southern Nurseries
Authors: Fraedrich Stephen W. , Dwinell L. David
Published: August 2019

The use of dazomet as a fall and spring fumigant for pine seedling production and control of soilborne pests was evaluated at two southern nurseries. Dazomet was applied at low (280–325 kg/ha) and high (493–560 kg/ha) rates and incorporated with a rototiller or spading machine. Comparisons were made with methyl bromide/chloropicrin (MBC) fumigation and nonfumigated control treatments. Dazomet incorporation method had no effect on seedling density at either nursery, and often did not affect seedling morphological characteristics. At the Georgia (GA) nursery, seedling density and morphological characteristics did not differ among fumigant treatments except in the spring study area where shoot weight was greater in the MBC treatment than the dazomet or nonfumigated control treatments. In the fall study area at the North Carolina (NC) nursery, seedling density was greater in the high-rate dazomet treatment than the nonfumigated control. Seedlings were generally larger in MBC and dazomet treatments than the control. Seedling density and morphological characteristics did not differ among fumigation treatments in the spring study area. Fumigation with MBC or dazomet generally reduced the percentage of roots withPythium andFusarium spp. compared to controls at the GA nursery and the fall fumigation area in the NC nursery. Plant parasitic nematodes were found infrequently at both nurseries and did not differ among treatments. Nutsedge (Cyperus spp.) was the major problem at the GA nursery and was effectively controlled only with MBC. Compared to the MBC treatment, the abundance of soilborne fungi and the association of certain types ofTrichoderma with roots was often lower in the dazomet treatments. The importance of these differences for long term seedling production and management of soilborne diseases is not known at this time. South. J. Appl. For. 27(1):41–51.
Log Grade Prediction for Standing Yellow-Poplar Trees in Eastern Kentucky
Authors: Hilpp G. Keith , Pelkki Matthew H.
Published: August 2019

Information on the quality of logs in standing trees can aid resource managers and landowners in maximizing returns from timber harvests. However, little is published about the grade of logs in yellow-poplar (Liriodendron tulipifera) stands. In this study, discriminant analysis was used to develop classification functions to predict USDA Forest Service Log Grades for standing yellow-poplar trees in eastern Kentucky. The variables used to predict log grade are those commonly collected during forest inventory. This analysis indicates the importance of log position, merchantable height, and tree grade to log grade determination. The classification functions developed from the modeling data set correctly classified 80.9% of the log grades in a validation data set. These results provide a framework to resource managers and landowners for assessing yellow-poplar log quality in standing trees. South. J. Appl. For. 27(1):61–65.
Effects of Orifice-Weir Outlet on Hydrology and Water Quality of a Drained Forested Watershed
Authors: Amatya D.M. , Skaggs R.W. , Gilliam J.W. , Hughes J.H.
Published: August 2019

Orifice-weir structures at ditch outlets are proposed to reduce peak drainage rates during high flows and to store water during the growing season in poorly drained managed pine plantations. Two coastal watersheds, one conventionally drained (D1) and another with an orifice-weir outlet (D3), were monitored to examine the effects of this orifice treatment on drainage outflows and nutrient exports from drained pine plantations in eastern North Carolina. Five years (1995–1999) of measured hydrologic data showed that the daily water table elevation on D3 was 7 cm higher on average, but was 13.5 cm higher during wet periods compared to conventional drainage. The peak drainage rates from D3 were substantially dampened by the orifice-weir. Accordingly, average annual outflow was reduced by 18%. The reduction in outflow was as much as 34% in 1995. Taking the characteristic differences observed in concentrations between these two watersheds during the pretreatment phase into consideration, the measured average annual TKN concentration in the watershed with the orifice appeared to be higher, and total P and sediment lower than expected for conventional drainage. Despite the reduction of flow in all 5 yr, the measured exports of NO3-N, TKN, and total N increased in the first 3 yr (except for TKN in 1995) and decreased in 1998 and 1999 with no significant effects because of the orifice-weir treatment. However, on an average annual basis, total sediment and total P export from D3 were reduced by 54% and 30%, respectively. These results showed that an orifice-weir at the drainage outlet can be used to reduce peak rates, annual drainage outflows, total P and sediment export. The orifice-weir outlet did not have an effect on the export of nitrogen components as happens when controlled drainage with a raised weir is used. South. J. Appl. For. 27(2):130–142.
Effects of Thinning in a Cherrybark Oak Plantation
Authors: Pelkki Matthew H. , Colvin Robert J.
Published: August 2019

A cherrybark oak plantation was established on an Upper Coastal Plain creek bottom in southwest Arkansas in 1962. At age 10, treatments of (1) thinning only, (2) thinning and pruning, and (3) a control (no treatment) were applied in three replicates. Repeated thinnings from below occurred in the thinned and thinned/pruned plots at ages 21, 26, and 31. Pruning was applied in the thin/prune plots only once, at age 10. Thinning had significant effects on diameter growth immediately and continued to accelerate diameter growth through age 39, but had no effect on total tree height. Height to live crown was significantly lower for thinned plots than in the control. Pruning appeared to have no effect on diameter, height, or number or height of epicormic branches. Sawtimber volume and accumulated sawtimber production was significantly greater in treatments that received thinning, with potential for greater economic returns. The reader is cautioned that these results may not be indicative of cherrybark oak plantations in the South due to the size of the study area and possible edge effects. South. J. Appl. For. 28(1):55–58.
Site Suitability and Economic Aspects of Black Walnut (Juglans nigra L.) in Mississippi
Authors: Schultz Emily B. , DeLoach Walter M.
Published: August 2019

A site suitability study and economic analysis were conducted for naturally occurring black walnut (Juglans nigra L.) in Mississippi using 60 fifth-acre plots established during 2000. Soil, site, and tree measurements were used to: (1) construct site index (SI) curves and a nondestructive method for predicting walnut age; (2) classify diameter growth potential; (3) characterize suitable planting sites; and (4) project monetary returns. Bottomland fronts, flats, and ridges and upland toe slopes were the most frequently occurring natural black walnut sites and produced average diameter growth of 0.5 in./year. Growth was not significantly (P > 0.1) influenced by soil nutrients, pH, or site factors; however, a small portion of variation was positively correlated to silt percentage (P = 0.01–0.09;R2 = 0.05–0.12) and negatively correlated to sand percentage (P = 0.01– 0.09;R2 = 0.05–0.11). Clay textured soils were absent at all sampling depths. Land dedicated to black walnut management yielded up to 5.4 times the land expectation values of loblolly pine (Pinus taeda L.) where SIs for both species were 100. Favorable growth rates and monetary returns demonstrated that black walnut production has substantial economic potential for forest landowners in Mississippi. South. J. Appl. For. 28(3):123–131.
Nursery Practices Influence Seedling Morphology, Field Performance, and Cost Efficiency of Containerized Cherrybark Oak
Authors: Howell Kirk D. , Harrington Timothy B.
Published: August 2019

To quantify effects of nursery practices on seedling cost and performance, cherrybark oaks (Quercus pagoda L.) were grown in three container sizes (170, 650, or 1,250 cm3) with or without fertilization and then planted Dec. 1995 at a site near Milledgeville, GA, with or without removal of container soil. Initial size, biomass, and leaf area of seedlings grown in medium and large containers were up to twice those grown in small containers, and they were greater with versus without fertilization. Price efficiency (stem volume divided by estimated nursery price of 1,000 seedlings) was greatest for medium and large containers with soil removed and hypothetically reused. Differences in stem diameter and height due to container size and fertilization continued to diverge through the fifth year after planting. Fifth-year yield (stem volume × proportionate survival of 1,000 planted seedlings) increased 104, 56, and 31% with increasing container size and with fertilization and soil removal, respectively. Cost efficiency (fifth-year yield divided by costs compounded 5 years at 5% interest) was greatest for medium and large containers with soil removed. Joint comparisons of nursery costs, planting costs, and field performance for different seedling stock types provide an objective approach for prioritizing cultural treatments in forestry. South. J. Appl. For. 28(3):152–162.
The Financially Optimal Loblolly Pine Planting Density and Management Regime for Nonindustrial Private Forestland in East Texas
Authors: Huang Ching-Hsun , Kronrad Gary D. , Morton Jason D.
Published: August 2019

Economic analyses were conducted to investigate the effects of initial planting density on the profitability of loblolly pine (Pinus taeda L.) on nonindustrial private forestland (NIPF) in East Texas. Five planting densities of 870, 725, 620, 540, and 484 trees per acre (tpa)representing spacings of 5×10, 6×10, 7×10, 8×10, and 9×10 ft, respectively, were investigated. Land expectation values were used to determine the financially optimal thinning and final harvesting schedules (including rotation length and the timing, frequency, and intensity of thinning). Five site indices (50–90), six real alternative rates of return (ARR) (2.5–15.0%), and three thinning options (0, 1, and 2) were employed. Results indicate that two thinnings appear to be the financially optimal number of thinnings for most siteindex-ARR scenarios. The planting spacing of 8×10 ft is optimal when ARR is low, and the 9×10 ft spacing is optimal when ARR is high. South. J. Appl. For. South. J. Appl. For. 29(1):16–21.
Effects of Carbon Markets on the Optimal Management of Slash Pine (Pinus elliottii) Plantations
Authors: Alavalapati Janaki R.R. , Stainback G. Andrew
Published: August 2019

Global climate change is a growing concern among many policy makers. This concern has led to substantial interest in using forests as one option to mitigate climate change. In this article, the effect of internalizing carbon sequestration benefits on the optimal management of slashpine plantations is explored. Results suggest that without carbon benefits, it is optimal to use herbicide and bedding but not fertilizer because the increase in timber yield does not justify the high cost of fertilizer. With carbon benefits, however, the use of fertilizer becomes profitable.Thus a carbon market would likely induce plantation owners to increase their management intensity, which may in turn also have significant impacts on the amount of carbon sequestered. For example, by allowing the management regime to vary in addition to rotation age, the amount of carbon sequestereddecreased from 204 to 164 metric tons of carbon per acre when carbon prices increased from $40 to $200 per metric ton. Thus increasing carbon sequestration on the intensive margin may be less feasible than previously supposed, but increasing on the extensive margin may be highlypracticable South. J. Appl. For. 29(1):27–32.
Impact of Spring Sawfly Defoliation on Growth of Loblolly Pine Stands
Authors: Zeide Boris , Thompson Lynne C.
Published: August 2019

To estimate the impact of a single spring defoliation by loblolly pine sawfly (Neodiprion taedae linearis Ross), diameters of 3,006 loblolly pines from five locations in southeastern Arkansas were measured immediately after defoliation and two more times at 1-year intervals.The proportion of defoliation was assessed at each measurement. An insecticide was used in an attempt to prevent defoliation in subsequent years. Because tree growth depends on many factors, a multivariate multiple regression model was used to separate these effects. The model predicts thata single defoliation reduces annual diameter and volume increment by 17.4, 8.4, and 2.8% for the first, second, and third years after defoliation, respectively (the actual loss was 18.9 and 8.9% for the first 2 years). It was found that trees defoliated 20–40% actuallygrew faster than undefoliated trees. This response, called overcompensation, is a common reaction of plants to moderate stress. Potential losses from defoliation are greatest in sawtimber-sized stands between the ages of 25 and 35 years. The decision to control sawflies should take into accountstand age and time to final harvest. South. J. Appl. For. 29(1):33–39.