bluuebunny/crossref_metadata_2025_split huggingface dataset:
Tree Nutrition and Forest Fertilization of Pine Plantations in the Southern United States
Authors: Fox Thomas R. , Lee Allen H. , Albaugh Timothy J. , Rubilar Rafael , Carlson Colleen A. 
Published: August 2019

Abstract
The growth of many pine plantations in the southern United States is limited by soil nutrient availability. Therefore, forest fertilization is a common silvicultural practice throughout the South. Approximately 1.2 million ac of pine plantations were fertilized in 2004. In the last 10 years, considerable advances have been made in identifying the ecophysiological basis for stand growth and the response to fertilizer additions. Nitrogen (N) and phosphorus (P) are the nutrients that most commonly limit growth of southern pine. On wet clay soils in the lower Coastal Plain and on some well-drained soil in the upper Coastal Plain, severe P deficiencies exist. On these soils, P fertilization with 25–50 lb of P per acre at the time of planting produces a large and sustained growth response, on the order of 50 ft3 ac−1 yr−1 (1.5 tn ac−1 yr−1) throughout the rotation. On most other soils in the South, chronic deficiencies of both N and P exist. On these sites, soil nutrient availability often is adequate early in the rotation when tree demand is small. However, around the time of crown closure, N and P frequently become limiting. Fertilization with both N and P in these intermediate aged stands typically increases growth for 8–10 years. The growth response to a combination of 25 lb of P per acre plus 200 lb of N per acre averages around 55 ft3 ac−1 yr−1 (1.6 tn ac−1 yr−1) for an 8-year period. The amount of leaf area in the stand is the main factor determining the current growth rate of the stand and the potential growth response after fertilization. When stand leaf area index is less than 3.5, light capture by the stand is restricted and growth is negatively affected. In many of these stands, fertilization will increase leaf area because of increased soil nutrient availability and thus increase growth. The financial return after fertilization depends on the growth response that occurs, the cost of the fertilizer treatment, and the stumpage value of the timber produced. Using a growth response of 55 ft3 ac−1 yr−1 over 8 years, a fertilizer cost of $90 ac−1, and stumpage values from the first quarter of 2006, the internal rate of return from midrotation fertilization of a loblolly pine plantation with N and P would be approximately 16%.
The Southern US Forest Bioenergy Encyclopedia: Making Scientific Knowledge More Accessible
Authors: Gan Jianbang , Rauscher H. Michael , Smith C.T. , Ashton Sarah , Biles Larry , Cassidy Daniel , Foster Darwin , Howell Matthew R. , Hubbard William G. , Jackson Ben , Mayfield Chyrel , Mead Donald J. , Silveira Semida , Taylor Eric 
Published: August 2019

Abstract
Production of forest biomass in sustainably managed forests in the southern United States has great potential to improve forest health, make energy supplies more secure, and increase the social and economic welfare of rural communities. The awareness and access of landowners and forestry and natural resource professionals to new knowledge and market development opportunities must be increased, and new technological advances in knowledge dissemination systems can be very useful in this connection. The Encyclopedia of Southern Bioenergy was developed within The Forest Encyclopedia Network (www.forestencyclopedia.net/) to facilitate the transfer of useable knowledge from scientific experts in bioenergy and bio-based products to natural resource professionals, landowners, and the general public. Using the encyclopedia as a base, a team of bioenergy and extension education experts has developed several new educational products. These materials are designed as components of an overall biomass training program for the South that is being disseminated through the Southern Regional Extension Forest network.
A Mixed-Effects Model for the dbh–Height Relationship of Shortleaf Pine (Pinus echinata Mill.)
Authors: Budhathoki Chakra B. , Lynch Thomas B. , Guldin James M. 
Published: August 2019

Abstract
Individual tree measurements were available from over 200 permanent plots established during 1985–1987 and later remeasured in naturally regenerated even-aged stands of shortleaf pine (Pinus echinata Mill.) in western Arkansas and eastern Oklahoma. The objective of this study was to model shortleaf pine growth in natural stands for the region. As a major component of the shortleaf modeling effort, an individual tree-level dbh–total height model was developed in which plot-specific random parameters were fitted using maximum-likelihood methods. The model predicts tree height on the basis of dbh and dominant stand height (which could be obtained from a site-index model). The mixed-effects model approach was found to predict the total height better than the similar models developed previously for this species using ordinary least-squares methods. Moreover, such a model has the appeal of generalization of the results over a region from which the plots were sampled; and also of calibration of parameters for newly sampled stands with minimal measurements.
Hurricane Katrina Impacts on Mississippi Forests
Authors: Oswalt Sonja N. , Oswalt Christopher , Turner Jeffery 
Published: August 2019

Abstract
Hurricane Katrina triggered public interest and concern for forests in Mississippi that required rapid responses from the scientific community. A uniform systematic sample of 3,590 ground plots were established and measured in 687 days immediately after the impact of Hurricane Katrina on the Gulf Coast. The hurricane damaged an estimated 521 million trees with more than 2.5-cm dbh and killed approximately 54 million trees statewide. Sixty-nine percent of tree mortality occurred in 17 counties in southeastern Mississippi, and 45% of trees killed were loblolly pine trees. Total tree mortality was less than 1% of the statewide population.
Efficacy of Basal Girdling to Control Oak Wilt Fungal Mat Production in Texas Red Oak (Quercus buckleyi) in Central Texas
Authors: Greene Thomas A. , Reemts Charlotte M. , Appel David N. 
Published: August 2019

Abstract
Woodlands dominated by Ashe juniper (Juniperus ashei) and oaks, including Texas red oak (Quercus buckleyi; synonyms: Quercus texana, Quercus shumardii var. texana), serve as breeding habitat for the endangered golden-cheeked warbler (Dendroica chrysoparia) in central Texas. Oak wilt, caused by the fungus Ceratocystis fagacearum, is considered a threat to habitat quality for this warbler. Basal girdling was tested for controlling fungal mat production on Texas red oak and for reducing disease spread at the stand level. For 2 years, symptomatic trees were girdled by stripping bark from the lower trunks in late summer. Trees were inspected the following spring for mats. Basal girdling reduced the overall proportion of infected stems that produced one or more fungal mat from 9.7 to 2.5%. Among mat-producing stems, basal girdling reduced the mean number of mats per stem from 4.78 ± 0.73 (least squares mean ± 95% confidence interval) to 2.78 ± 1.34. Probability that a stem would produce one mat or more was positively correlated with dbh and was significantly reduced by the basal girdling treatment. Two years of treatment did not affect 3rd-year infection levels within treated stands. However, the study design we used could not exclude local tree-to-tree spread of the pathogen through common/grafted roots. We suggest that basal girdling, used as a stand-alone practice, may not be effective in controlling the local spread of C. fagacearum in central Texas woodlands.
A Comparison of GPS Performance in a Southern Hardwood Forest: Exploring Low-Cost Solutions for Forestry Applications
Authors: Danskin Scott D. , Bettinger Pete , Jordan Thomas R. , Cieszewski Chris 
Published: August 2019

Abstract
The global positioning system (GPS) exhibits much potential for forestry applications, where traditional methods of position determination still dominate. Recent advances in GPS technology may offer improved performance of GPS in forested conditions, and at a considerable cost advantage compared with previous GPS alternatives. We examined the use of several mapping- to recreation-grade GPS receivers across a topographic gradient and the influence of using the Wide Area Augmentation System (WAAS) to their performance under leaf-on and leaf-off conditions. Generally, the mapping-grade receiver with postprocessed differential correction offered the highest position accuracies, which improved root mean squared error (RMSE95) from 3.64 to 5.32 m across leaf conditions, compared with recreation-grade receiver performance, which ranged in RMSE95 from 12.76 to 38.74 m under leaf-on conditions to 8.22 to 36.81 m under leaf-off conditions. Users of this information should keep in mind that RMSE95 equals actual RMSE × 1.7308. These results are consistent with the general thoughts that (a) mapping-grade receivers should provide higher horizontal position accuracy than consumer-grade receivers, (b) better horizontal position accuracy is obtained during leaf-off forest conditions (i.e., winter), (c) differential correction can improve horizontal position accuracy, and (d) WAAS, when available, can improve horizontal position accuracy. Results also indicate that slope position and the number of position fixes acquired may influence the performance of the GPS units.
Calibrating a Segmented Taper Equation with Two Diameter Measurements
Authors: Cao Quang V. 
Published: August 2019

Abstract
Recent advances in laser technology help make possible accurate and affordable measurements of upper-stem diameters. These measurements can be used to calibrate results from a taper equation to improve the accuracy of diameter predictions along the tree bole. Felled-tree data from a loblolly pine (Pinus taeda L.) plantation were used to evaluate two methods for calibrating outputs from a segmented taper equation with parameters either obtained from the data in this study or originally published by <xref ref-type="bibr" rid="B5-2124">Max and Burkhart (1976</xref>, Segmented polynomial regression applied to taper equations, For. Sci. 22:283–289). For outside-bark diameters, although a simple calibration for dbh gave desirable results, a better calibration involving both dbh and an upper-stem diameter provided significant improvements in predicting tree taper. Results varied depending on where the diameter was measured, with optimum gains obtained when the upper-stem diameter was measured at the midpoint between breast height and the tree tip. For inside-bark diameters, the calibration for inside-bark dbh actually produced inferior predictions, whereas the calibration based on both dbh and an upper-stem diameter offered only modest improvements over the unadjusted predictions.
Nine-Year Growth Responses to Planting Density Manipulation and Repeated Early Fertilization in a Loblolly Pine Stand in the Virginia Piedmont
Authors: Carlson Colleen A. , Fox Thomas R. , Creighton Jerre , Dougherty Phillip M. , Johnson John R. 
Published: August 2019

Abstract
Achieving maximum stand leaf area early in the rotation can have large positive effects on plantation productivity. Two silvicultural management strategies that can enhance leaf area development are increasing planting density and improving nutrition. A trial was established to determine how these two silvicultural management strategies affect the growth of Pinus taeda L. in the Virginia Piedmont. The study was designed as a factorial with two planting densities (363 and 726 trees ac−1) and three levels of nutrient additions. The three nutrient levels were aimed at maintaining the current site index (SI25) of the stand (55 ft) or improving the SI25 to 70 and 80 ft. None of the treatments affected survival or height during the first 9 years. At age 9, the lower stand density treatment had a greater average diameter (6.03 in.) compared with the high stand density treatment (5.10 in.) averaged across all nutrient levels. The intermediate and high nutrient treatments increased diameter by 0.21 and 0.35 in., respectively, compared with the low nutrient treatment (5.38 in.), when averaged across both stand densities. Intraspecific competition affected diameter growth from age 5, whereas nutrient additions increased growth from age 4.
Effect of Midstory Removal on Understory Light Availability and the 2–Year Response of Underplanted Cherrybark Oak Seedlings
Authors: Lhotka John M. , Loewenstein Edward F. 
Published: August 2019

Abstract
This study evaluates the effects of four midstory removal intensities on residual stand structure, understory light availability, and the 2-year growth and survival of underplanted cherrybark oak (Quercus pagoda Raf.) seedlings. It also examines whether survival and growth were affected by the removal of competing understory vegetation <1.4 m tall. The study was conducted in western Georgia, in a mature riparian hardwood forest possessing a dense midstory canopy and an understory dominated by highly competitive nonnative and native species. The removal of all midstory trees increased survival and height and basal diameter growth of cherrybark oak after two growing seasons. Understory light availability increased only when at least half of all midstory trees were removed. Although understory vegetation removal increased 2-year height growth of cherrybark oak, the actual growth difference between treatments was only 5 cm. The removal of understory vegetation had no effect on basal diameter growth or survival. Results suggests that a combination of underplanting and complete midstory removal may be a useful treatment for enhancing advance oak reproduction in riparian hardwood stands. This treatment combination may have utility as the initial step in a shelterwood system when advance reproduction is insufficient.
Implementing Regional Locale and Thinning Response in the Loblolly Pine Height-Diameter Relationship
Authors: Russell Matthew B. , Amateis Ralph L. , Burkhart Harold E. 
Published: August 2019

Abstract
This study uses two regionwide data sets, one exemplified by intensive management and the other by nonintensive management, to investigate whether including regional locale and thinning response improves the loblolly pine height–diameter relationship. Results showed that including geographic coordinates as scaled variables, in addition to including a thinning response modifier, reduces the variability of an individual-tree height model compared with a baseline model without these covariates. Holding stand conditions constant, tree height for a given diameter will generally be greater at south and east locales within the natural range of loblolly pine, and thinning will lead to slightly greater tree heights. Equations that include geographic locale of the stand and a thinning modifier that incorporates amount of time since thinning are proposed. These equations can be used for thinned or nonthinned stands throughout the natural geographic range of the species.
Aboveground Biomass Estimation for Three Common Woody Species in the Post Oak Savannah of Texas
Authors: Oswald Brian P. , Botting R. R. , Coble Dean W. , Farrish Ken W. 
Published: August 2019

Abstract
The post oak savannah of Texas contains many shrubs and trees species that lack standing biomass estimation. Nondestructive biomass prediction equations for dry weight (g) and fuel size classes (to accurately assess fuels hazards and potential fire behavior) were determined for post oak (Quercus stellata Wangenh.), eastern redcedar (Juniperus virginiana L.), and gum bumelia (Sideroxylon lanuginosum Michx. subsp. oblongifolium [Nutt] T.D. Penn) using basal diameter, height, and crown area. Five models (full model, full log model, combined variable model, logarithmic model, and combined variable model with crown area) were performed and compared. The logarithmic model provided the best results for predicting dry weight. The logarithmic model was the only one that performed well for any fuel size parameter (post oak foliage and eastern redcedar 1 hour fuel size).
Spectral Identification of Previsual Northern Red Oak (Quercus rubra L.) Foliar Symptoms Related to Oak Decline and Red Oak Borer (Coleoptera: Cerambycidae) Attack
Authors: Riggins John J. , Defibaugh y Chávez Jason M. , Tullis Jason A. , Stephen Frederick M. 
Published: August 2019

Abstract
A severe oak decline event associated with the outbreak of an insect pest (Enaphalodes rufulus [Haldeman]) affected the Arkansas, Missouri, and Oklahoma Ozarks from the mid-1990s through 2005. Tree mortality was severe and widespread, but patchy in nature. The rugged and remote terrain of the Ozarks led to difficulty in monitoring and assessing the location, severity, and spread of declining stands. In addition, visible symptoms of decline typically occur late in the decline-disease spiral, providing little early warning and leaving few options for mitigation. In situ spectroradiometry using handheld equipment offers an affordable option for characterizing the spectral signatures of plant stress and assessing the feasibility of areawide remote sensing projects without risking a large upfront investment in imagery. Foliage from 30 northern red oak (Quercus rubra L.) trees was sampled using a handheld spectroradiometer, and analysis was conducted using machine learning techniques. Analysis of 602 reflectance and first-derivative variables provided the best prediction (90%) of field-assigned stress rankings. Eight published vegetation stress indices used as surrogate variables yielded approximately 86% accuracy in predicting the correct field-assigned stress ranking. Therefore, use of vegetation stress indices as surrogate variables may be a simpler option for analyzing future imagery of oak stress in the Ozarks while sacrificing little accuracy.
Segmenting Southern Nonindustrial Private Forest Landowners on the Basis of Their Management Objectives and Motivations for Wood-Based Bioenergy
Authors: Joshi Omkar , Mehmood Sayeed R. 
Published: August 2019

Abstract
This study segments nonindustrial private forest (NIPF) landowners in Arkansas, Florida, and Virginia on the basis of their forest management objectives and their willingness to supply wood-based biomass for bioenergy. A two-step cluster analysis was used to segment NIPF landowners of all three states into three distinct groups, namely bioenergy conservationists, multiple-objective landowners, and passive landowners. The results revealed that there was notable variation among NIPF landowners in terms of their interest in wood-based bioenergy and forest management objectives. A solid majority of bioenergy conservationists (58%) were familiar with the concept of producing alternative fuels from wood. Similarly, multiple-objective landowners' willingness to supply wood-based biomass (63%) was highest among all three segments. Bioenergy-friendly conservationists and multiple-objective landowners were more likely to be receptive to outreach activities. Further, given low motivation scores for passive managers, this group of landowners would require focused outreach programs to increase their interest in bioenergy. This study suggested appropriate outreach and educational strategies to communicate with each audience segment.
A Decisionmaking Model for Managing or Regenerating Southern Upland Hardwood Forests
Authors: Cunningham Kutcher K. , Ezell Andrew W. , Belli Keith L. , Hodges John D. , Schultz Emily B. 
Published: August 2019

Abstract
A decisionmaking model was developed to assist hardwood resource managers in determining the management potential, for sawlog production, of southern upland hardwood stands within the Cumberland Plateau, Western Highland Rim, and Upper Coastal Plain physiographic provinces. The model determines stands to be either manageable (using intermediate stand management) or in need of regeneration. Stand index values were established for even-aged stands using stocking guidelines, individual tree characteristics, and tree class. Threshold index values for continued stand management were established for four sawtimber management objectives in the Cumberland Plateau and three sawtimber management objectives in the Western Highland Rim and Upper Coastal Plain. Stand index values above or below the threshold value returned a decision to continue to manage or initiate regeneration methods for a stand, respectively. In the Cumberland Plateau and Western Highland Rim provinces, a similarity of percentage between model decisions and decisions from an expert panel of hardwood silviculturists was calculated to assist in determining model effectiveness. The overall agreement between the model and experts was 71%.
Use of Prescribed Burning to Enhance Southern Pine Timber Production
Authors: Crow A. Bigler , Shilling Charles L. 
Published: August 2019

Abstract
Prescribed burning benefits pine timber production in many ways. It can facilitate regeneration and early stand development, control unwanted vegetation, reduce loss from certain diseases, thin overdense young stands, make working in an area easier and cheaper and, perhaps, encourage increased growth and yield. In most cases it enables the management objective to be achieved at reduced cost. As with any use of prescription fire, it must be carefully and skillfully applied to minimize loss and avoid adverse environmental effects.
Paulownia—A Crop Tree for Wood Products and Reclamation of Surface-Mined Land
Authors: Tang R. C. , Carpenter S. B. , Wittwer R. F. , Graves D. H. 
Published: August 2019

Abstract
Paulownia, a naturalized Asiatic species, has been widely planted in the southeastern United States as a shade and ornamental tree because of its rapid growth and beautiful flowers. Although its multiple-use properties have made it an important commercial wood in Japan, it has not been used commercially in the United States. Recently, increased demand for paulownia from Japanese wood industries has created a potential new market for U.S. production of the species. The botanical characteristics, habitat conditions, forestation techniques, and economic potential of paulownia are reported. Also discussed is its utilization in reclamation efforts on surface-mined lands.1
Electronic Technology Speeds Forest Survey
Authors: Beltz Roy C. , Keith George C. 
Published: August 2019

Abstract
Electronic data recorders have been successfully applied in field activities of the continuous forest survey. A new data-entry system minimizes the transition trained cruisers must make from tally sheets to digital entry. Telecommunications, data capture, and subsequent processing are reliable and efficient. Keypunching costs, time requirements, and associated errors are eliminated. The recorders are light, compact, and can communicate with a variety of computer hardware.
Current Use of Remote Sensing by Foresters in the South
Authors: Mead Roy A. , Rasberry D. Ann 
Published: August 2019

Abstract
A survey was conducted to determine how and to what extent remote sensing is being used for forest management in the 13 southern states. Several general conclusions were reached. Timber type mapping and road location are the major uses of aerial photographs. Professional resource managers spend a small portion of their time interpreting aerial photographs and very few photo interpreters are employed on a full-time basis. Significant differences were apparent in the use of aerial photographs by different organizations. Black-and-white photographs are most frequently used. Color and color infrared photography were utilized by all organizations to a limited extent, but Landsat, radar, and thermal imagery were generally not used. Very little use is being made of small-format (35 mm and 70 mm) photography. More applied research and practical training are needed to fully implement remote-sensing techniques in the field of natural resources.