bluuebunny/crossref_metadata_2025_split huggingface dataset:
Estimating Tree Diameter and Volume with a Taper Model and Large-Scale Photo Measurements
Authors: Hall R.J. , Wang Y. , Morgan D.J. 
Published: August 2019

Abstract
Large-scale photo (LSP) mensurational procedures were developed, in part, to reduce field costs by replacing much of the ground sampling with less expensive photo measurements. The conventional LSP approach uses photo measurements of tree height and crown area, which serve as independent variables in models, to predict tree diameter or volume. This study compared 18 linear and nonlinear model forms for estimating tree diameters and assessed the use of a provincial taper model to estimate total tree volume from LSP data. On average, linear models produce R2, root mean square error, and mean bias values that were at least equivalent to, if not statistically better than, nonlinear models for the range of data evaluated. For lodgepole pine, white spruce and a composite of two deciduous species (trembling aspen and balsam poplar), total volume estimates were not statistically different from those estimated from field measurements. A comparative analysis of LSP and field sampling costs suggests the use of taper models in LSP mensuration could save considerable cost and effort in data collection and model development. This finding may result in an increased use of LSP in operational forest inventory work. North J. Appl. For. 18(4):110–118.
Comparison of Field Methods and Models to Estimate Mean Crown Diameter
Authors: Bechtold William A. , Mielke Manfred E. , Zarnoch Stanley J. 
Published: August 2019

Abstract
The direct measurement of crown diameters with logger's tapes adds significantly to the cost of extensive forest inventories. We undertook a study of 100 trees to compare this measurement method to four alternatives—two field instruments, ocular estimates, and regression models. Using the taping method as the standard of comparison, accuracy of the tested alternatives was adequate for softwood species, but short of the specified measurement quality objective for estimating the mean crown diameter of hardwoods. Due to savings in field costs, ocular estimation and regression models were the best alternatives to direct measurement with logger's tapes.
New Approaches to Uneven-Age Management in New England
Authors: Leak William B. , Gottsacker James H. 
Published: August 2019

Abstract
Because of greater emphasis on nontimber values in New England, uneven-age management is drawing more interest among the larger ownerships. Uneven-age management approaches recommended in the past were both costly and biologically undesirable. However, recent findings are enabling the development of more feasible uneven-age guidelines for regenerating valuable species, conducting practical cutting operations, controlling marking, and keeping records. North J. Appl. For. 2:28-31, March 1985.
A Stocking Guide for European Larch in Eastern North America
Authors: Gilmore Daniel W. , Briggs Russell D. 
Published: August 2019

Abstract
European larch is a fast-growing exotic species that shows promise in alleviating projected fiber supply shortages with numerous plantations being established in the Lake States, the Northeast, and Canada during the last two decades. Prescribing thinning regimes for these plantations would be facilitated through the use of a stocking chart. Few older plantations exist in North America, however, thus fitting equations to construct an A-line that requires data from a large number of stands is not possible. We introduce a new approach to constructing an A-line by using the stand density index that in essence is a modification of the traditional tree area ratio approach. We then invoke the self-thinning rule to produce a reference line for Maximum Average Density and an equation for open-grown trees to produce a reference line for Full Site Occupancy in the construction a stocking chart for field use. We also provide yield estimates by diameter class at maximum and minimum stocking levels. North. J. Appl. For. 20(1):34–38.
Natural Resource Professional Continuing Education Needs in Minnesota: Focus on Forest Management Guidelines
Authors: Eliason Sara K. , Blinn Charles R. , Perry James A. 
Published: August 2019

Abstract
Approaches to forest management are changing as the public's expectations for forest resources broaden, environmental concern grows, and scientific knowledge about forests advances. Natural resource professionals rely in part on continuing education to stay abreast of new ideas and strategies for managing forest resources. In Minnesota, new voluntary timber harvesting and forest management guidelines are changing forestry, and continuing education is a vital strategy for encouraging use and demonstrating the application of these nonregulatory guides. To ensure that such educational programs are successful, a series of focus groups was conducted to learn about natural resource professionals' education needs with regard to the voluntary timber harvesting and forest management guidelines. This needs assessment reveals that natural resource professionals want to become familiar with the rationale and background behind the guidelines, learn how to work with the flexibility built into the guidelines, and practice making decisions about which guidelines to use in various situations. Natural resource professionals prefer outdoor workshops with loggers that allow for interaction among participants. We present recommendations for conducting forest management guideline education programs; these recommendations also apply generally to education programs for other natural resource professionals. North. J. Appl. For. 20(2):71–78.
Crown Position and Light Exposure Classification—An Alternative to Field-Assigned Crown Class
Authors: Bechtold William A. 
Published: August 2019

Abstract
Crown class, an ordinal tree-level mensuration attribute used extensively by foresters, is difficult to assign in the field because definitions of individual classes are confounded by ambiguous references to the position of the tree in the canopy and amount of light received by its crown. When crown class is decomposed into its two elements—crown position and crown light exposure—field assignments are more repeatable, and crown class can be assigned by algorithm with the same degree of accuracy that it can be estimated in the field. Replacing traditional crown class with the two proposed alternative variables yields more specific information about each tree. Crown position and crown light exposure add information potentially useful for modeling and other applications. North. J. Appl. For. 20(4): 154Â160.
Timber Supply Projections for Northern New England and New York: Integrating a Market Perspective
Authors: Sendak Paul E. , Abt Robert C. , Turner Robert J. 
Published: August 2019

Abstract
The North East State Foresters Association (NEFA) commissioned a study that resulted in the publication of a report titled, “A Forest Resource Model of the States of New York, Vermont, New Hampshire, and Maine.” In this article we used the integrated NEFA computer simulation framework to go beyond the reported results and further explore the effects on the forest resource in terms of timber harvest, inventory, and price under various market and demand assumptions. Five scenarios were run through the integrated SRTS-ATLAS model to project long-run effects on timber inventory (growing stock) and price. Besides reflecting differing assumptions about demand and supply, these scenarios defined different markets, thus affecting how the wood harvest was allowed to move across the region in response to demand. Regionally, at the end of the 50 yr projection period, cubic-foot growth and harvest were approximately in balance in the Reference Case, the scenario that we felt was most likely. Initial inventory on all timberland was 66.7 billion ft3. By 2050, inventory volume increased 13% to 75.4 billion ft3. Net growth declined over the 50 yr period from 35.3 to 32.1 ft3 ac-1 yr-1, while harvest increased from 26.6 to 31.9 ft3 ac-1 yr-1. Regional real price increased approximately 1.1% yr-1 over the period. Changes in the resource situation in one state affect the situation in the other states. There is a mutual dependence in markets that policy makers need to recognize. The integration of a market module into the NEFA modeling process added the interplay of market forces and improved upon the policy information available from the model.
Impacts of Long-Term Diameter-Limit Harvesting on Residual Stands of Red Spruce in Maine
Authors: Sokol Kerry A. , Greenwood Michael S. , Livingston William H. 
Published: August 2019

Abstract
Diameter-limit harvesting has long been suspected as a dysgenic forestry practice, but a conclusive, practical demonstration of the effects of this selection technique on residual tree performance is lacking. To determine the effects of repeated diameter-limit harvesting on the phenotypes of residual trees, we compared radial growth patterns of residual red spruce trees (with ages greater than 100 years) after diameter-limit harvests with those of residual trees in stands subjected to positive selection harvesting. After nearly 50 years of repeated harvesting, residual trees in the diameter-limit stands were nearly 40% smaller and had grown 32% slower than residual trees in positive selection stands. Furthermore, diameter-limit residuals were initially smaller and remained significantly smaller than positive selection residuals throughout their lifespan, despite major release events. After release, the diameter-limit trees responded with increased growth rates, but the increase was relatively small. Growth rates were consistently and significantly lower for diameter-limit residuals until the final 20 yr when growth rates in each treatment converged. Our results indicate that red spruce stands subjected to repeated diameter-limit harvesting will develop progressively less valuable growing stock with limited growth potential.
GIS Protocols in Mapping Ecological Landtypes for the Hoosier National Forest
Authors: Shao Guofan , Parker Geroge R. , Zhalnin Andrey V. , Merchant Patrick , Albright Deb 
Published: August 2019

Abstract
GIS protocols were developed to map ecological landtypes (ELTs) containing dry slopes, mesic slopes, dry ridges, mesic ridges, and bottomlands for the Hoosier National Forest, Indiana, United States. The mapping techniques included separating hills from valleys, dividing hills into north- and south-facing slopes, differentiating narrow from wide ridges, and noise removal with raster and vector methods. This article examined ELT mapping with both 30- and 10-m resolution data. This article also compared different GIS operations involved in ELT mapping. The accuracy of the ELT map created was assessed on the ground, and accuracy could reach 100% if boundary-location and small-area errors were excluded. The GIS protocols involved in this study were effective and have broad implications for mapping ELTs in other geographic areas. For larger areas, more automated GIS procedures will be necessary. North. J. Appl. For. North. J. Appl. For. 21(4):180–186.
Who Will Log in Maine's North Woods? A Cross-Cultural Study of Occupational Choice and Prestige
Authors: Egan Andrew , Taggart Deryth 
Published: August 2019

Abstract
Two distinct populations of loggers work in Maine's border counties with Quebec: Maine resident and Quebec resident woodsworkers. This study compared the sense of occupational choice and prestige held by these workers, as well as their sociodemographic attributes. Significant differences in age, education, and logging experience were found between these two populations. In addition, Maine resident loggers appeared to exhibit less resignation to woods work than their Quebec counterparts. However, Quebec resident loggers indicated that their profession was held in higher esteem among the public than did loggers from Maine. Over two-thirds of respondents from both populations would not encourage a son/daughter to be a logger, despite considerable familial attachment to logging. Results may have implications for logging labor supply, labor recruitment efforts, and logging mechanization in a region heavily dependent on the forest products industry. North. J. Appl. For. 21(4):200–208.
Forest Blowdown Prediction: A Correlation of Remotely Sensed Contributing Factors
Authors: McMaster Kevin J. 
Published: August 2019

Abstract
On July 15, 1995, a severe windstorm in northern New York affected thousands of acres of forest. A heterogeneous impact by the high winds was captured by two Landsat Thematic Mapper (TM) images taken prior to and following the event. This article uses landscape position, vegetation cover, and edaphic conditions of the damaged areas in an attempt to quantify and explain the differential impact by the wind on the forest. Using remote sensing and geographic information system (GIS) technologies, significantly correlated variables of six site factors were used to predict damaged areas for a 50-square-mile study site. However, the predicted areas had an overall accuracy of only 60%, with a kappa coefficient of 0.22, indicating that the storm impact was too complex to be reliably predicted using the available site variables. North. J. Appl. For. 22(1):48–53.
Performance of Green Ash Seed Sources at Four Locations in the Great Plains Region
Authors: Geyer Wayne A. , Lynch Keith D. , Row John , Schaeffer Peter , Bagley Walter 
Published: August 2019

Abstract
Green ash trees from 10 seed sources were planted in a test in 1961 in four states of the Great Plains Region. After more than 20 years, height growth indicates a strong interaction between seed source and plantation location. Larger trees were from southerly sources within about three degrees of latitude of the plantation site. Beyond those limits, cold injury may result. Height and dbh age-age correlations were highly significant at 8 and 20+ years. Height and dbh correlated negatively with a decrease in latitude. North. J. Appl. For. 22(1):54–58.
Assessment of Factors Contributing to Residual Tree Damage from Mechanized Harvesting in Northern Hardwoods
Authors: Seablom Thomas J. , Reed David D. 
Published: August 2019

Abstract
Seven northern hardwood stands were evaluated for damage after mechanized harvesting. Four different harvesting systems were evaluated: harvester and grapple skidder, processor and forwarder, chainsaw and cable skidder, and chainsaw and forwarder. There was not an excessive amount of damage occurring to any of the residual stands, and there was an adequate number of residual trees per acre in all diameter classes to meet residual stand structure goals. The majority of the damage that did occur was to the bole portion of the tree and to the 2–8-in. dbh size classes. There was no strong relationship between amount of damage occurring to residual trees and the number of residual trees per acre, residual basal area per acre, or distance to skid trail. These results indicate that mechanized harvesting can be used in northern hardwoods without causing excessive damage to the residual stand. Recommendations are to continue with current silvicultural prescriptions and to increase forester-operator communication to minimize residual tree damage.North. J. Appl. For. 22(2):124–131.
Comparison of Fixed Diameter-Limit and Selection Cutting in Northern Conifers
Authors: Kenefic Laura S. , Sendak Paul E. , Brissette John C. 
Published: August 2019

Abstract
Diameter-limit cutting is a common type of harvest in which all merchantable trees above specific size thresholds are removed. Despite a long history of application, controlled experiments of these harvests are rare and the cumulative effects of repeated diameter-limit cuts are largely unknown. The Penobscot Experimental Forest in Maine is the location of a long-term USDA Forest Service experiment in which both fixed diameter-limit and selection cutting have been applied at 20-year intervals since the early 1950s. After three entries, present value of gross harvest revenue was greater in the fixed diameter-limit than selection treatments. However, sawtimber volume and growth, total and merchantable volume, regeneration stem density, and inventory value all were lower in the fixed diameter-limit than selection stands. Accumulated value (harvest plus residual) and species composition did not differ between treatments. Within-treatment analysis revealed desirable directional changes in cull percentage and species composition in the selection but not diameter-limit cut stands, suggesting trends that may result in greater future treatment disparity. These data confirm the degrading effects of fixed diameter-limit relative to selection cutting, and reveal that greater short-term value removals are offset by lower residual stand volume and value. North. J. Appl. For. 22(2):77–84.
Prescribing Fire in Eastern Oak Forests: Is Time Running Out?
Authors: Abrams Marc D. 
Published: August 2019

Abstract
Before European settlement, vast areas of the eastern US deciduous forest were dominated by oak species. Evidence indicates that periodic understory fire was an important ecological factor in the historical development of oak forests. During European settlement of the late 19th and early 20th century, much of the eastern United States was impacted by land-clearing, extensive timber harvesting, severe fires, the chestnut blight, and then fire suppression and intensive deer browsing. These activities had the greatest negative impact on the once-dominant white oak, while temporarily promoting the expansion of other oaks such as red oak and chestnut oak. More recently, however, recruitment of all the dominant upland oaks waned on all but the most xeric sites. Mixed-mesophytic and later successional hardwood species, such as red maple, sugar maple, black birch, beech, black gum and black cherry, are aggressively replacing oak. The leaf litter of these replacement species is less flammable and more rapidly mineralized than that of the upland oaks, reinforcing the lack of fire. The trend toward increases in nonoak tree species will continue in fire-suppressed forests, rendering them less combustible for forest managers who wish to restore natural fires regimes. This situation greatly differs from the western United States, where fire suppression during the 20th century has made a variety of conifer-dominated forests more prone to stand-replacing fire.North. J. Appl. For. 22(3):190 –196.
Stock Quality Assessment of a Somatic Interior Spruce Seedlot
Authors: Grossnickle Steven C. , Folk Raymund 
Published: August 2019

Abstract
Somatic embryogenesis is a form of vegetative propagation that uses tissue culture procedures to rapidly multiply elite genotypes of a selected tree species. Somatic embryogenesis technology still is considered novel by the forest industry for use within forest regeneration programs. In this article, a stock quality testing approach was used to compare a somatic seedlot to comparable zygotic seedlots. The somatic seedlot was comprised of interior spruce (Picea glauca (Moench) Voss × Picea engelmannii Parry ex. Engelm.) crosses (PG × PG), white spruce (P. glauca (Moench) Voss) crosses (ENA × ENA), or a mixture thereof (PG × ENA or ENA × PG). This somatic seedlot was compared to zygotic orchard-collected seedlots that shared partial parentage with the somatic seedlot. Seedlings produced from all seedlots were container-grown under standard nursery cultural procedures. Height and rootcollar diameter were measured on all seedlots. Shoot growth potential (i.e., length of new leader elongation) and root growth capacity were measured under controlled environment conditions. Mean height and diameter of the somatic and zygotic seedlots fell within a similar range that met operational grading criteria for a plantable seedling. The somatic and zygotic seedlots also had similar shoot and root growth capability. Comparable stock quality assessment performance between the somatic and zygotic seedlots indicated that somatic embryogenesis is a viable vegetative propagation technology for producing seedlings suitable for reforestation programs. North. J. Appl. For. 22(3):197–202.
Connecticut's Tree Wardens: A Survey of Current Practices, Continuing Education, and Voluntary Certification
Authors: Ricard Robert M. 
Published: August 2019

Abstract
Since 1918, Connecticut state law has required the appointment of a tree warden who assumes responsibility for public trees in that municipality. A major, if not the primary, responsibility of municipal government is public safety and yet local government is also charged with protecting and enhancing the economic, social, and environmental well-being of the community. As a result, the tree warden has to balance public safety and conservation. This is only possible when tree wardens are well trained. However, state statutes do not require a tree warden to posses any relevant qualifications or to participate in continuing education. Following a 1991 needs assessment, several educational initiatives were started to increase tree warden knowledge. To increase tree warden participation, two approaches were considered. One was to amend existing state law to mandate training. A second was to encourage participation in educational programs through voluntary certification. The second approach was taken when a Tree Warden School and Tree Warden Certification Program was initiated in 1998. Results from a statewide needs assessment found that tree wardens participated in more continuing education opportunities in 2001 than they did in 1991, with a large percentage becoming Connecticut Certified Tree Wardens.
Concepts about Forests and Water
Authors: Stuart Gordon W. , Edwards Pamela J. 
Published: August 2019

Abstract
Six concepts concerning forests, forestry, and water resources are discussed: (1) the role of the forest canopy in erosion control; (2) the impact of disturbance on soils; (3) the variability of natural water quality; (4) the impact of harvesting on water quality; (5) the role of extreme experiments; and (6) the effectiveness of forestry best management practices (BMP). The literature shows that the forest floor, not the canopy, protects soils from erosion. Harvesting can be conducted in ways that limit compaction and essentially confine overland flow to areas of exposed mineral soil on roads, trails, and log landings. Overland flow from these areas can be controlled and converted to subsurface flow before it reaches streams and lakes. Thus, effects to watershed hydrology are small. Undisturbed watersheds tend to have better quality water than highly disturbed watersheds, but the undisturbed character of a catchment does not assure high-quality water. Undisturbed forests vary greatly in sediment and chemical exports that are controlled by variables such as streamflow, soils, geology, air pollution, and land use history. Conversely, timber harvesting does not necessarily have measurable or biologically meaningful negative effects on water quality. Forestry BMP have proven effective in controlling adverse changes to in-stream sediment and water chemistry. Many studies that have reported large changes in water quality often represent extreme treatments not associated with typical forest operations, or they have not employed BMP. Properly and adequately used forestry BMP protect watershed resources while allowing the removal of wood products.