bluuebunny/crossref_metadata_2025_split huggingface dataset:
Site-Index Curves and Growth Intercepts for Young White Spruce Plantations in North Central Ontario
Authors: Carmean Willard H. , Hazenberg Gerrit , Thrower James S. , LaValley Richard R. 
Published: August 2019

Abstract
Site-index (heightߝgrowth) curves, site-index prediction equations, and growth intercepts were developed from internode measurements and stem-analysis data using dominant trees in 69 plots located in white spruce plantations aged 19 to 32 years total age. Site-index curves were based on breast-height (1.3 m) age because our analyses show that height growth below breast height is slow and erratic and is poorly related to site index (dominant height at 15 years breast-height age). The most precise model for computing heightߝgrowth curves was a Newnham constrained polymorphic expression (Newnham, R.M. 1988. A modification of the Ek-Payandeh nonlinear regression model for site-index curves. Can. J. For. Res. 18:115ߝ120) of the Ek nonlinear regression model (Ek, A.R. 1971. A formula for white spruce site-index curves. University of Wisconsin For. Res. Note 161. 2 p). Comparisons showed that site-index curves in North Central Ontario were comparable to site-index curves for white spruce plantations in southeastern Ontario. The first three to five internodes above 2.0 m gave the most precise estimates of site index based on growth intercepts. North. J. Appl. For. 23(4):257–263.
Sixty Years of Change in the Sapling Understories of Northern Hardwood Selection Stands in New Hampshire
Authors: Leak William B. 
Published: August 2019

Abstract
Numbers of understory saplings in northern hardwood stands on granitic soils harvested once or twice by single-tree selection were monitored on 1/4-ac cruise plots from 1931–32 to 1990–91. Beech, which composed somewhat less than half the stems, either increased slightly or declined; hemlock and striped maple increased substantially, whereas sugar maple declined. The decline in sugar maple saplings may have resulted from the influence of logging disturbances prior to 1931–32, which produced early successional vegetation conducive to sugar maple regeneration, followed by single-tree selection harvests that minimized any early successional influence. North. J. Appl. For. 23(4):301–303.
Effects of Mechanical Site Preparation on the Abundance and Diversity of Ground-Layer Vegetation in Adirondack Northern Hardwood Stands
Authors: Forrester Jodi A. , Bohn Kimberly K. 
Published: August 2019

Abstract
Forest management in northern hardwoods benefits from the use of site preparation treatments when the amount of American beech (Fagus grandifolia Ehrh.) and fern species in the understory interferes with regeneration of more desirable species, e.g., sugar maple (Acer saccharum Marshall). We assessed the cover and diversity of herbaceous and woody species in the ground layer of three Adirondack northern hardwood stands before and 3 years after a mechanical site preparation that removed all trees less than 14 cm with a brush saw. The treatment significantly increased the cover of all species cumulatively, with herbaceous, shrub, and arborescent species increasing significantly more in treated plots than in untreated plots. Sugar maple cover increased more in treated plots than in untreated plots, although American beech did as well. Species richness increased significantly more in treated plots than in untreated plots, but differences in diversity and evenness were not significantly different because of treatment after 3 years. Multivariate analysis indicated only minor changes in the plant community composition. Results show that mechanical site preparation techniques are a viable option for promoting abundance and maintaining diversity of the ground-layer vegetation in northern hardwood forests.
Stand Density Management Diagram for Jack Pine Stands in Eastern Canada
Authors: Sharma Mahadev , Zhang S.Y. 
Published: August 2019

Abstract
A stand density management diagram was developed for jack pine (Pinus banksiana Lamb.) stands using the data obtained from 125 permanent sample plots (PSPs) established in Ontario and 232 PSPs in Quebec, Canada. The diagram was evaluated using data from 40 PSPs established in Ontario. Recently developed and efficient models have been used in constructing the diagram to estimate diameters and heights for the trees for which no diameters or heights were recorded at the time of stand inventory. Relative density indices of 0.15, 0.40, and 0.55 were used, corresponding to the line of approximate crown closure, the limit of productive zone, and the lower limit of competition-related mortality, respectively. If two stand characteristics are known, including mean total tree volume, quadratic mean diameter, trees per hectare, and average dominant height, the others can be readily obtained using the diagram. The consequences of various thinning scenarios can be plotted and visualized in the field without the need for computer simulation.
Interference to Hardwood Regeneration in Northeastern North America: Pin Cherry and Its Effects
Authors: Nyland Ralph D. , Bashant Amy L. , Heitzman Eric F. , Verostek Jane M. 
Published: August 2019

Abstract
Pin cherry grows rapidly in a bright environment, overtopping most desirable hardwood species. Its rapid early development helps to reduce nutrient losses from a site and provides a source of mast for wildlife. Some pin cherry trees live for up to 45–50 years, but their abundanceusually decreases after 30–35 years. Pin cherry begins producing abundant seeds at an early age, and high proportions of these remain viable in the forest floor for up to 6–7 decades. Germination has been linked to high availability of nitrogen (N) in the forest floor, either followingfertilization or increased decomposition of the humus layer. Heavy overstory cutting or natural disturbances that reduce stocking below 50–60 ft2/ac in stands <90 years old will promote N release from the forest floor, resulting in abundant pin cherry within the new cohort.When at high density, pin cherry interferes with the development of most other species, and those of intermediate or low shade tolerance may die. Pin cherry may have a patchy distribution across a stand or form an almost complete canopy cover when well distributed at high densities. Its arrangementmay affect long-term stand composition and development. Where milacres have ≥3 pin cherry ≥3 ft tall, or >1 of them >5 ft in height, a release treatment may prove necessary to ensure good levels of stocking with desirable hardwoods of seedling origin. Landowners should pay particularattention when they find a high pin cherry density across more than 30–40% of the stand area. These criteria may indicate where a release treatment would improve the composition of young hardwood stands.
Butt and Root Decay in Precommercially Thinned SpruceߝFir Stands
Authors: Tian Suzhong , Ostrofsky William D. 
Published: August 2019

Abstract
To test the effect of precommercial thinning (PCT) on butt decay development, 10 commercial thinning size spruceߝfir stands that were precommercially thinned 10ߝ24 years ago and seven unthinned (UT) control stands were assessed for butt decay incidence. The data indicate that PCT did not increase butt decay incidence for either red spruce or balsam fir compared with UT control stands. However, butt decay incidence increased with dbh, height, age, and years of PCT for balsam fir. These relationships were not found for red spruce. No significant PCT treatment effect was found for either species in root decay incidence (RDI) by examining all roots 1.0 cm or greater in diameter of 80 crop trees. RDI of balsam fir increased as root size increased. A significant relationship (r2 = 0.835) exists between RDI and butt decay proportion in the horizontal stump section for balsam fir. To evaluate whether the PCT operation resulted in the removal of butt-decayed stems preferentially, 55 10 × 10 m plots of precommercially thinned spruceߝfir stands were surveyed within 2 years after thinning. A total of 1,426 red spruce stumps; 2,471 balsam fir stumps; 441 retained red spruce trees; and 419 retained balsam fir trees were examined. The results showed that the practice of PCT tended to result in selecting a higher proportion of decayed trees as crop trees. Overall, 5.7% of retained trees and 1.6% of stumps were determined to have decay for red spruce, and 15.8% of retained trees and 5.6% of the stumps had decay for balsam fir.
HeightߝDiameter Equations for 12 Upland Species in the Missouri Ozark Highlands
Authors: Lootens James R. , Larsen David R. , Shifley Stephen R. 
Published: August 2019

Abstract
We calibrated a model predicting total tree height as a function of tree diameter for nine tree species common to the Missouri Ozarks. Model coefficients were derived from nearly 10,000 observed trees. The calibrated model did a good job predicting the mean heightߝdiameter trend for each species (pseudo-R2 values ranged from 0.56 to 0.88), but for a given tree diameter observed tree heights were highly variable. We also present a technique for incorporating the observed variation in tree heights in the predicted values.
Silvicultural Options to Reduce Pine Susceptibility to Attack by a Newly Detected Invasive Species, Sirex noctilio
Authors: Dodds Kevin J. , Cooke Robert R. , Gilmore Daniel W. 
Published: August 2019

Abstract
A nonnative woodwasp of Eurasian origin, Sirex noctilio F., was detected recently in Oswego, New York, infesting Scots, red, and white pine. S. noctilio has caused periodic widespread losses of pine timber resources in several Southern Hemisphere countries and may cause significant damage in pure even-aged stands and overstocked plantations in North America. However, stand management and biological control programs have successfully managed S. noctilio populations in other countries and similar programs are being developed for North America. Until the primary biological control agent, Beddingia siricidicola, a parasitic nematode, is established in North America, forest owners will have to rely solely on silvicultural treatments to reduce the susceptibility of at-risk pine stands to S. noctilio attack. Silvicultural treatments including precommercial thinning, promoting optimal growing conditions for pines on a given site, reducing numbers of susceptible hosts, and consistent monitoring of stands are suggested activities to help protect pine stands from invasion by S. noctilio.
Stand Structure and Composition in a Northern Hardwood Forest after 40 Years of Single-Tree Selection
Authors: Neuendorff Jonathan K. , Nagel Linda M. , Webster Christopher R. , Janowiak Maria K. 
Published: August 2019

Abstract
Uneven-aged northern hardwoods of the Great Lakes region are managed primarily through single-tree selection harvesting. We quantified species composition and stand structure after 40 years of single-tree selection in five stands as compared with three stands that were untreated for 40 years. Relative density and importance value of sugar maple significantly increased under single-tree selection, whereas relative density of yellow birch significantly decreased and eastern hemlock remained unchanged. Contemporary seedling and saplings layers were dominated by sugar maple regardless of treatment, but unmanaged stands contained more species. Diameter distribution varied over time and between unmanaged and managed stands. Increasing-q was the most common distribution shape in 2004, and there was no clear trend toward a negative exponential or rotated sigmoid distribution over time. Our results suggest that long-term single-tree selection may result in regeneration of fewer tree species commonly found in this forest type, with potential implications for future stand structure.
Methods to Convert Local Sampling Coordinates into Geographic Information System/Global Positioning Systems (GIS/GPS)–Compatible Coordinate Systems
Authors: Rudnicki Mark , Meyer Thomas H. 
Published: August 2019

Abstract
Laying out a sampling transect in the field is a common task when researching natural systems and resources. With widespread availability of global navigation satellite systems (GNSS), such as the US global positioning system (GPS), it is becoming more common to resurvey legacy transects to establish them in globally referenced coordinate systems such as geodetic latitude/longitude or planimetric systems such as the Universal Transverse Mercator (UTM) or the State Plane Coordinate System (SPCS). Transforming local coordinates into a globally referenced coordinate system allows (1) disparate legacy surveys to be combined into a common geographic information system (GIS) database, (2) new GPS measurements to be incorporated into that same database, and (3) GPS-based navigation to be used for plot establishment and resampling. This article presents the mathematics necessary to determine the globally referenced planimetric coordinates of established linear, rectangular, or nominally rectangular transects (such as a rhombus) using formulas that are easily implemented on a spreadsheet. In addition, methods are given to determine the planimetric coordinates of new transects.
Surface Compaction Estimates and Soil Sensitivity in Aspen Stands of the Great Lakes States
Authors: Steber Aaron , Brooks Ken , Perry Charles H. , Randy Kolka 
Published: August 2019

Abstract
Aspen forests in the Great Lakes States support much of the regional timber industry. Management-induced soil compaction is a concern because it affects forest health and productivity and soil erosion. Soil compaction increases bulk density and soil strength and can also decrease air and water movement into and through the soil profile. Currently, most inventories, and specifically the Forest Inventory and Analysis program, use qualitative estimates of soil compaction. This study compared qualitative estimates with quantitative measurements on aspen clearcuts in five national forests in the Great Lakes States. Research sites were stratified into classes of high and low potential for soil compaction on the basis of soil texture. Qualitative visual assessments of compaction were made according to Forest Inventory and Analysis (FIA) phase 3 protocols and compared with physical measurements of bulk density, soil compression strength, and saturated hydraulic conductivity. No differences in compaction between high- and low-risk soils were detected using visual assessments, but quantitative measurements in high-risk, fine-textured soils indicated greater compaction than low-risk, coarse-textured soils. These results illustrate shortcomings in qualitative estimates of compaction made according to FIA phase 3 field protocols. Inexpensive quantitative measurements, such as those taken with a pocket penetrometer, may be sufficient to quantify compaction levels within the plots.
Influence of Demographic Characteristics on Production Practices within the Ohio Maple Syrup Industry
Authors: Graham Gary W. , Goebel P. Charles , Heiligmann Randall B. , Bumgardner Matthew S. 
Published: August 2019

Abstract
Maple syrup production contributes approximately $5 million annually to Ohio's economy and provides supplemental nontimber forest product income for forestland owners. To better understand the factors that influence this important nontimber forest industry in Ohio, including producer heritage, producer age, sap collection methods, size of maple operation, and educational programming, we conducted a detailed survey of all known Ohio maple syrup producers (761 total producers). Over 80% of producers responded to the survey (620 respondents), making our analysis one of the most extensive of a maple industry in North America. In general, most maple operations in Ohio are part-time, family-based enterprises and over 25% of Ohio's maple producers are of Amish heritage. Although we estimate that there are over 400,000 taps in the state, the typical sugarbush is relatively small—the average sugarbush is 27 ac in size and over a third of the operations have fewer than 100 taps. Chi-square analyses did reveal several significant (α = 0.05) associations among producer characteristics. Although Amish producers were significantly younger and had significantly larger operations than their English or non-Amish counterparts (P < 0.001), a higher proportion of English producers reported using tubing collection systems than Amish producers (P = 0.031). Additionally, while larger maple operations tended to use tubing systems more frequently (P < 0.001), we did not detect a significant association between sap collection method (bucket versus tubing) and producer age (P = 0.169). Finally, English producers tend to be older. Older producers (>53 years old), producers using tubing collection systems, and producers with more than 250 taps were significantly more likely to participate in Ohio State University (OSU) Extension educational programming (P ≤ 0.05). These results suggest significant relationships among producer demographics and the characteristics of maple operations in Ohio, and future OSU educational programming should be tailored to reflect these important relationships.
Using Forest Service Forest Inventory and Analysis Data to Estimate Regional Oak Decline and Oak Mortality
Authors: Kromroy Kathryn W. , Juzwik Jennifer , Castillo Paul , Hansen Mark H. 
Published: August 2019

Abstract
Damage and mortality data are collected as part of the US Forest Service, Forest Inventory and Analysis (FIA) ongoing assessments of the nation's timberlands. The usefulness and value of FIA tree data in assessing historical levels of oak decline and oak mortality were investigatedfor seven Midwestern states. The data were collected during two periodic inventories conducted between the early 1970s and the mid-1990s. One-tenth to one-third of the oak trees had decline-associated damage in a given inventory, but no trends over time were apparent across the states. Thepercentages of dead trees ranged from less than 1 to 11 across all inventories and states; mortality was higher in the late inventory than the early inventory for all states. This is the first reported attempt to quantify oak decline across the Midwestern Region and it was accomplished using FIA tree data. The major concerns of the approach used are the subjective nature of the damage codes used to tabulate declining oaks and the inconsistencies and inherent subjectivities in the FIA recorded codes. The major drawback for non-FIA researchers is the time required to understand the intricacies of the FIA system.
Accuracy of Tree Grade Projections for Five Appalachian Hardwood Species
Authors: Miller Gary W. , Graves Aaron T. , Gottschalk Kurt W. , Baumgras John E. 
Published: August 2019

Abstract
The potential value increase of individual trees is an important factor in planning effective forest management strategies. Similar to other investments, trees with high potential value increase are retained and allowed to grow, and those with relatively low potential value increaseare harvested so that the proceeds may earn a higher rate of return elsewhere. Tree grade is used to assess the quality and value of wood within a tree; thus, projecting tree grade is an integral part of estimating potential value increase. This study measured the accuracy of projected treegrades over a period of 12–15 years for 588 black cherry, 404 northern red oak, 167 red maple, 191 white and chestnut oaks, and 450 yellow-poplar sawtimber trees in both thinned and unthinned stands. Projected grade was based on surface defects and percent volume deductions for sweep,crook, and rot at the time of the projection with the assumption that the threshold dbh for the highest possible grade would be reached in the future. This approach allows the forest manager to make grade projections based on what is visible and measurable on the tree, even if the tree iscurrently too small to qualify for higher grades. In general, grade projections were somewhat accurate, with 9% of trees higher than the projected grade, 80% projected correctly, and 11% lower than the projected grade. Trees that had a lower-than-projected grade usuallyexhibited additional deductions for percent cull volume and/or new epicormic branches. Grade projections were less accurate for larger, higher-quality trees because requirements for the top grade are more constraining and sensitive to changes in butt log characteristics than lower grades.For black cherry and northern red oak, grade projections in thinned stands were less accurate compared with unthinned stands because of resulting logging wounds or new epicormic branches.
Oak Regeneration Guidelines for the Central Appalachians
Authors: Steiner Kim C. , Finley James C. , Gould Peter J. , Fei Songlin , McDill Marc 
Published: August 2019

Abstract
This article presents the first explicit guidelines for regenerating oaks in the central Appalachians. The objectives of this paper are (1) to describe the research foundation on which the guidelines are based and (2) to provide users with the instructions, data collection forms, supplementarytables, and decision charts needed to apply the guidelines in the field. The principal research foundation for the guidelines is a set of quantitative models that estimate, in advance of harvest, a stand's potential to regenerate oak stocking from advance regeneration and stump sprouts. Regeneration potential is measured by the predicted stocking by oak species, expressed as a percentage of full (100%) stocking, in the new stand in its third decade (21–30 years) after overstory removal. An understory classification system is used in conjunction with the models to help identifypotential barriers to regeneration development. Model results and other data on current stand conditions are used in the decision charts to identify prescriptions for achieving a strong component of oak regeneration after stand harvest. Overstory removals are recommended when the stand's oak regeneration potential is adequate to meet management goals. Otherwise, prescriptions designed to enhance seedling-origin oak regeneration potential are recommended.
Family Forest Landowners' Interest in and Perceptions of Forest Certification: Focus Group Findings from Minnesota
Authors: Leahy Jessica E. , Kilgore Michael A. , Hibbard Calder M. , Donnay Jacob S. 
Published: August 2019

Abstract
Focus groups were organized with individuals owning between 15 and 720 forested acres in northern Minnesota to better identify their understanding of, questions about, and interest in forest certification; factors that would encourage or discourage their participation in certificationprograms; and the types of certification program characteristics they preferred. Family forest landowner participants were generally unfamiliar with the concept of forest certification. They expressed concern about certification costs and benefits, its impact on land-use decisionmaking, eligibility requirements, and program administration. They also expressed clear preferences about how forest certification programs should be tailored to family forest landowners. The availability of financial assistance to help cover initial and ongoing certification costs, assurance that certification will not encumber property rights, and clear and tangible benefits were found to positively influence their interest in participation. The perspectives of other family forest landowners influenced individual attitudes toward certification. Moreover, initial attitudes toward forest certificationonly became more entrenched as landowners were provided additional information about certification—skeptics became more disinterested while those inclined to participate became even more so. Recommendations for foresters, forest policymakers, and forest certification program leaders are presented that would encourage more family forest landowner participation in certification.