Predicting Site Index for Old-Field Loblolly Pine Plantations

1981 ◽  
Vol 5 (3) ◽  
pp. 109-114 ◽  
Author(s):  
Michael S. Golden ◽  
Ralph Meldahl ◽  
Steven A. Knowe ◽  
William D. Boyer

Abstract Height-over-age curves and site-index prediction tables were derived using nonlinear polymorphic regression models with data from 25-year-old old-field plantations ranging from coastal North Carolina to southwestern Arkansas. Plots from heavy silty clay soils of the interior flatwoods of Mississippi exhibited height growth patterns noticeably different from the overall pattern. A separate table and set of curves were developed for such sites.

1990 ◽  
Vol 7 (1) ◽  
pp. 27-30 ◽  
Author(s):  
James H. Brown ◽  
Charles A. Duncan

Abstract Growth intercept (GI) techniques were evaluated for estimating site quality in red pine stands planted on old-field sites in the unglaciated Western and Central Allegheny Plateau regions of Ohio. Correlations between height growth of trees below breast height (BH) and height growth above BH were not statistically significant. Site index estimates were made using age at BH and height from BH to the growing tip. Three-year and 5-year growth beginning three internodes above the BH annual increment and 10-year growth beginning one internode above BH were more significantly correlated with height than were intercepts beginning at BH. In equations developed for predicting site index, 3-, 5-, and 10-year intercepts in combination with age accounted for 64 to 80% of the variation in tree heights. Combining thickness of the A soil horizon with GI and age statistically increased the variation accounted for in the 3- and 5-year GI equations; however, for field use, the improvement in accuracy was not sufficient to justify making the additional soil measurement. North. J. Appl. For. 7(1):27-30, March 1990.


2004 ◽  
Vol 19 (3) ◽  
pp. 154-159 ◽  
Author(s):  
G. Geoff Wang ◽  
Shongming Huang ◽  
David J. Morgan

Abstract Based on the provincial stem analysis and permanent sample plot (PSP) data of 1,580 felled dominant and codominant trees, height growth patterns of lodgepole pine were compared among the three major natural subregions [Sub-Alpine (SAL), Upper Foothills (UFH), and Lower Foothills (LFH)] in Alberta. The comparison used the ratio of heights at 70 and 30 years of breast height age (Z ratio) as a quantitative measure of height growth pattern (i.e., the response variable), site index (height at breast height age of 50 years) as the covariate, and natural subregion as the factor. Results indicated that: (1) the height growth pattern in the SAL natural subregion was significantly different from other natural subregions; and (2) no significant differences in height growth pattern were found between other natural subregions. Two polymorphic height and site index curves were developed: one for the SAL natural subregion and the other for the UFH and LFH natural subregions. Comparisons between the two curves and the previously developed provincial curve indicated that, for the same site index, trees in the SAL subregion grow consistently slower after 50 years. When the provincial height and site index curve was applied to the SAL natural subregion, large differences (≤14%) in gross volume estimation were found. However, volume estimation differences were very small (<2%) when the provincial curve was applied to the other two natural subregions. It is recommended that the natural subregion-based curves should be used for predicting lodgepole pine site index or height at any age in the SAL natural subregion. West. J. Appl. For. 19(3):154–159.


1985 ◽  
Vol 9 (3) ◽  
pp. 166-169 ◽  
Author(s):  
Ralph L. Amateis ◽  
Harold E. Burkhart

Abstract Stem analysis data collected from dominant and codominant loblolly pine (Pinus taeda) trees in cutover, site-prepared plantations were used to develop site index curves. The data were collected over much of the natural range of loblolly pine. A separable differential equation which expresses height growth as a function of both height and age was used to develop the site index curves. These site index curves should be applicable to loblolly pine plantations on cutover, site-prepared lands through much of the South.1


1989 ◽  
Vol 4 (4) ◽  
pp. 136-142 ◽  
Author(s):  
Joseph E. Means ◽  
Thomas E. Sabin

Abstract On the Siuslaw National Forest in the central Oregon Coast Range we performed stem analysis of 55 trees selected with the criteria used by the forest. Height growth patterns of these trees were significantly different (α = 0.05) from commonly used regional height growth curves. Height growth patterns also differed significantly among groups of floristically similar plant associations in the Siuslaw National Forest. We constructed height growth and site index curves for two classes of plant associations having different height growth curve forms and for the combined data. Forest managers should consider building local height-growth and site-index curves if these are important in estimating stand yield or site productivity. West. J. Appl. For. 4(4):136-142, October 1989


2001 ◽  
Vol 77 (1) ◽  
pp. 141-150 ◽  
Author(s):  
Willard H. Carmean ◽  
G. Hazenberg ◽  
G. P. Niznowski

Stem-analysis data from dominant and codominant trees were collected from 383 plots located in fully stocked, even-aged, undisturbed mature jack pine stands. Separate site index curves were independently formulated for four regions of northern Ontario using the Newnham constrained nonlinear regression model; these formulations were used for comparing regional site index curves at three levels of site index (10 m, 15 m and 20 m).Comparisons showed that no significant differences existed between the four regional curves as well as with previously published site index curves for the North Central Region. Each of the four regions had similar polymorphic height-growth patterns; therefore, data for the four regions were combined and a single formulation was used to develop a polymorphic set of site index curves for all of northern Ontario. We found that poor sites in each region had almost linear height growth up to 100 years breast-height age, but for each region height growth became more curvilinear with increasing site index. The recommended site index curves for northern Ontario are based on a formulation using only data from plots 100 years and less but this formulation was not significantly different from a formulation using only data from plots 80 years and less, or a formulation that included all data from plots older than 100 years breast-height age.Comparisons were made between our northern Ontario curves and other jack pine site index curves for Ontario as well as curves for other areas of Canada and the United States. These comparisons generally showed considerable older age differences. Reasons for these differences are uncertain but could be due to differences in the amount and kind of data used for these other curves, could be due to differences in analytical methods, or could be due to regional differences in climate, soil and topography. Key words: site quality evaluation, polymorphic height growth, regional site index curves, site index prediction equations, comparisons among site index curves.


2006 ◽  
Vol 36 (8) ◽  
pp. 1959-1967 ◽  
Author(s):  
Joshua P Adams ◽  
Thomas G Matney ◽  
Samuel B Land Jr. ◽  
Keith L Belli ◽  
Howard W Duzan Jr.

Differences in survival, diameter, height (site index), and stem profile among eight North Carolina half-sib families and one Mississippi–Alabama commercial check of loblolly pine (Pinus taeda L.) at three spacings over 17 years were evaluated for effects on a growth-and-yield model. Actual stand volume at age 17 was determined from a 100% measurement of all trees. This volume was compared with predicted volumes from age nine measurements using (i) the unmodified model and (ii) the model after modifications for family differences. Modifications to the model included family-specific site indices for height differences and family-specific regression functions for each of the other traits. The unmodified model resulted in an underestimate of actual stand volume by 31%. Adjustments for family differences in dominant height (site index), survival, or profile had little effect on this bias. Insertion of family-specific regressions for stem profile and site index in combination with survival-diameter density effects greatly reduced the bias and provided the best estimates of future stand volumes.


2015 ◽  
Vol 45 (8) ◽  
pp. 1026-1033 ◽  
Author(s):  
Micky G. Allen ◽  
Harold E. Burkhart

Site index curves are generally developed from one of three data sources: (i) permanent sample plots, (ii) temporary sample plots, or (iii) stem analysis data. Permanent sample plots are considered to be the best data source for modeling height–age relationships; however, due to time and cost constraints, analysts may consider using temporary sample plots or stem analysis data for equation fitting. Temporary sample plot and stem analysis data, although more quickly obtained, require assumptions that are often not met when modeling site index. The question becomes how models developed from temporary sample plot or stem analysis data compare with models developed from permanent sample plot data. Data from a region-wide study in loblolly pine (Pinus taeda L.) plantations were used to develop site index curves from each of the three data sources. A form of the Chapman–Richards model was used for all three data sources to guard against confounding and to discern differences among the data sources when modeling height–age relationships. For the comparison and evaluation of behavior of different functions, the Schumacher model was also fitted to the three data sources. Curves developed from temporary sample plot and stem analysis data did not reproduce the height growth pattern exhibited in permanent sample plots, although curves derived from temporary plots were closer to the height growth pattern.


1991 ◽  
Vol 21 (3) ◽  
pp. 306-317 ◽  
Author(s):  
Constance A. Harrington

Height growth by year and by individual cycle on the terminal shoot was reconstructed from stem analysis for 45 loblolly pine (Pinustaeda L.) trees that were 35 years old. Sample trees represented three seed sources (Clark County, AR; Livingston Parish, LA; and Onslow County, NC), each of which had been planted at three installations (Arkadelphia, AR; Poplarville, MS; and New Bern, NC) located in the general geographic area where one of the seed sources had been collected. Stem analysis was facilitated by the development of a staining technique that enhanced recognition of the boundaries between individual height-growth cycles and between years. Both annual height growth and number of cycles produced varied with tree age, seed source, and installation. Number of cycles produced per year ranged from two to seven; maximum annual production of cycles per seed source was achieved between ages 3 and 10 years. Even between ages 30 and 35, trees still exhibited polycyclic behavior, producing two to five cycles annually. Annual height growth was greatest between ages 4 and 15; height growth declined with age more rapidly than annual number of cycles. The relationship at each installation between cumulative height and cumulative number of cycles showed that the tallest seed source (Onslow in all cases) was the one that had produced the greatest number of cycles. Shorter trees at the poorest site resulted from lower numbers of cycles produced and, particularly after the production of 50 to 65 cycles, shorter mean cycle length. For all three seed sources, mean height was greatest at the installation where the trees produced the most cycles. Height-growth curves for two of the installations crossed, demonstrating differences in height-growth patterns related to site characteristics.


1990 ◽  
Vol 7 (3) ◽  
pp. 129-133
Author(s):  
James H. Brown ◽  
Charles A. Duncan

Abstract Multiple regression equations using topographic and soil factors were developed for predicting height growth and site index for red pine planted on old-field sites in the unglaciated Western and Central Allegheny Plateau Regions of Ohio. Regression equations containing slope position and aspect combined with tree age accounted for 58% of the variation in heights of trees. Height growth increased with A soil horizon thickness, and adding that variable to equations increased the variation explained to 61%; conversely, growth decreased as clay content of the B soil horizon increased and adding that factor further increased the variation accounted for to 66%. North. J. Appl. For. 7:129-133, September 1990.


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