bluuebunny/crossref_metadata_2025_split huggingface dataset:
Impacts of Rotation Age Changes on Growth/Removals Ratios
Authors: Prisley Stephen P. , Malmquist Andrew J. 
Published: August 2019

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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.
Risk Assessment with Current Deployment Strategies for Fusiform Rust-Resistant Loblolly and Slash Pines
Authors: Bridgwater Floyd , Kubisiak Tom , Byram Tom , McKeand Steve 
Published: August 2019

Abstract
In the southeastern USA, fusiform rust resistant loblolly and slash pines may be deployed as 1) ulked seed orchard mixes, 2) half-sibling (sib) family mixtures, 3) single half-sib families, 4) full-sib family mixtures, single full-sib families from 5) “bulking up” or producing large numbers of controlled cross seeds, or as 6) clones of individual genotypes. These deployment types are respectively less genetically variable and less well buffered against environmental stress, but provide respectively greater genetic gains from higher selection intensity. Currently, bulked seed orchard mixes are deployed by all state organizations and many smaller companies, but about half the 1.1 billion loblolly and slash pines deployed annually are planted in half-sib family blocks. The most aggressive landowners plant virtually all of their land with a small number of half-sib families. Full-sib families and/or clones are currently planted on a small fraction of the total area regenerated, but research and development seeks to make the deployment of full-sib families and clones economical to increase the genetic gains from applied tree improvement programs. Resistance to fusiform rust currently being deployed is likely due to resistance based on both major genes and genes of small, cumulative effects. However, major genes for resistance to fusiform rust have been discovered using molecular genetic techniques, and deployment strategies are currently being developed. “Boom and bust” cycles of pathogens on other crops when major genes were deployed against them create concerns that these same problems might arise when deploying major genes for resistance against fusiform rust. We assessed the risk that fusiform rust might overcome one to few major genes for resistance if they are deployed widely and strategies to mitigate the risk that this will occur. We concluded that the deployment strategies currently in widest use (bulked seed orchard seedlings and half-sib family blocks) robustly resist fusiform rust infection. Plantations are probably sufficiently genetically buffered to present little risk of cataclysmic failure, as current resistance is likely to be based on both major and minor genes. Furthermore, these same deployment strategies are likely to provide robust protection against risk factors other than fusiform rust. We concluded that deploying pine cultivars with known genes for major resistance to fusiform rust in regions where their associated virulence genes are absent or in low frequencies is a practical near term strategy and that deploying a mosaic of different resistance genes may mitigate the presumed greater risk of deploying full-sib family blocks or clones. South. J. Appl. For. 29(2):80–87.