scholarly journals Compatible taper and volume equations for yellow-poplar in West Virginia

2004 ◽  
Author(s):  
Lichun Jiang
2005 ◽  
Vol 213 (1-3) ◽  
pp. 399-409 ◽  
Author(s):  
Lichun Jiang ◽  
John R. Brooks ◽  
Jingxin Wang

2007 ◽  
Vol 24 (4) ◽  
pp. 271-275 ◽  
Author(s):  
Lichun Jiang ◽  
John R. Brooks ◽  
Gerald R. Hobbs

Abstract Linear and nonlinear crown ratio (CR) functions were incorporated into a segmented taper and cubic foot volume function developed for yellow-poplar in West Virginia. The inclusion of a CR variable provided significantly different parameter estimates but only modest improvement in the prediction of upper stem size and volume. Sample trees from the west central region of West Virginia exhibited a larger improvement. The main differences were concentrated in the stem section above 60% of total height.


2009 ◽  
Vol 26 (1) ◽  
pp. 5-8 ◽  
Author(s):  
John R. Brooks ◽  
Lichun Jiang

Abstract The ability to predict inside bark diameters was investigated using taper data for red maple, red pine and yellow-poplar from several stands in West Virginia. Inside bark estimates were based on Grosenbaugh's STX prediction equations, a segmented polynomial taper function fitted to inside bark diameter data, an existing polynomial prediction equation published for several hardwood species in this region and a nonlinear prediction equation fitted to the taper data. Grosenbaugh's STX is a computer program for processing tree measurements and includes three equations to allow flexibility and greater accuracy in predicting inside bark upper stem diameters. The nonlinear equation had the smallest overall prediction error in almost all cases investigated. The taper function had the largest error but does not require knowledge of the specific upper stem outside bark diameter. No single STX bark option was found to be optimal for all species or for a single species from two different geographic regions.


2008 ◽  
Vol 25 (3) ◽  
pp. 151-153 ◽  
Author(s):  
Lichun Jiang ◽  
John R. Brooks

Abstract Compatible taper, volume, and weight equations were developed for planted red pine in West Virginia. The data were based on stem analysis of 26 trees from West Virginia University Research Forest, located in northern West Virginia. A commonly used segmented polynomial taper equation was chosen because of its balance between prediction accuracy and ease of use. Seemingly unrelated regression was used to simultaneously fit the system of equations for inside and outside bark data. When compared with existing total stem volume equations developed by Fowler (Fowler, G.W., 1997, Individual tree volume equations for red pine in Michigan, North. J. Appl. For. 14:53–58) and by Gilmore et al. (Gilmore, D.W., et al., 2005, Thinning red pine plantations and the Langsaeter hypothesis: A northern Minnesota case study. North, J. Appl. For. 22:19–25), a positive bias was evident that increased directly with stem diameter for trees from this region.


1982 ◽  
Vol 6 (3) ◽  
pp. 167-171 ◽  
Author(s):  
Michael S. Golden ◽  
Steven A. Knowe ◽  
Charles L. Tuttle

Abstract Volume equations of the form V = b0 + b1 D²H were developed to estimate total volume inside and outside bark for yellow-poplar (Liriodendron tulipfera L.) in the hilly Coastal Plain of Alabama. Volumes predicted using the outside-bark equation were determined to be different from those predicted by the comparable volume equation developed for southern Appalachian yellow-poplar. A nonlinear ratio model was developed to estimate the volume to any specified top diameter.


2007 ◽  
Vol 24 (2) ◽  
pp. 146-148 ◽  
Author(s):  
William Luppold ◽  
Delton Alderman

Abstract Over the last 40 years the composition of West Virginia forests has been changing as selective cutting practices have removed larger-diameter timber of specific species and partial canopy removal has fostered the regeneration of shade-tolerant species such as red maple. However, since the mid-1990s there has been considerable change in the number of markets accepting lower-quality and smaller-diameter roundwood, especially yellow-poplar. These changes have increased the number of roundwood markets and thus have increased the potential for harvesting based on silvicultural objectives or clearcuts. An examination of harvesting and merchandising practices for 28 harvest sites in West Virginia found an average of four merchandising separations or markets per site. Although the presence of new markets may have increased the section of sites containing yellow-poplar and the removal of this species from these sites, the continuation of diameter-limit cutting seems to have the greatest effect on which trees are removed. This pattern of partial harvests continues to favor the regeneration of shade-tolerant species such as red and sugar maple.


2007 ◽  
Vol 24 (2) ◽  
pp. 104-109
Author(s):  
John R. Brooks

Abstract Taper, cubic foot volume, and green weight equations to multiple top diameters were developed for the main bole portion of small-diameter black cherry (BC; Prunus serotina Ehrh.) and red maple (RM; Acer rubrum L.) trees in northern West Virginia. Sample trees were selected from the 2- to 5-in.-diameter class and ranged from 30 to 60 ft in total height. Existing published cubic foot volume equations provided estimates from 6 to 40% lower than estimates from the proposed model form, depending on species and tree size. Based on the published weight equations selected for comparison, differences between the estimates from the proposed models and from the published model with the smallest weight difference from a pool of candidate models, total bole green weight was underestimated from 5 to 93% for BC and from 0.4 to 25% for RM, depending on species and tree size.


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