A comparison of competition measures for predicting growth of loblolly pine trees

1986 ◽  
Vol 16 (6) ◽  
pp. 1230-1237 ◽  
Author(s):  
Richard F. Daniels ◽  
Harold E. Burkhart ◽  
Terry R. Clason
Keyword(s):  
Loblolly Pine ◽  
Relative Size ◽  
Stand Density ◽  
Tree Size ◽  
Size Ratio ◽  
Multiple Correlation ◽  
Individual Tree ◽  
Growth Prediction ◽  
Point Density ◽  
Stand Attributes

Five families of competition indices were evaluated and compared on the basis of simple correlation with loblolly pine individual tree growth and multiple correlation with growth in the presence of other tree and stand attributes. The family of distance-independent indices included various relative size measures in the form of tree size to mean size ratios. Crown ratio was also included as a distance-independent measure. The four families of distance-dependent indices included various influence area overlap indices, distance-weighted size ratio indices, Spurr's point density, and Brown's point density or area potentially available (APA). All indices were significantly correlated with dbh and basal area growth. The relative size ratio indices, crown ratio, Spurr's point density, and several APA variations were judged best in simple correlations after accounting for tree size and stand density. The best distance-dependent indices had little if any advantage, either in simple or multiple correlation, over the best distance-independent indices. However, the point density index of Spurr and especially APA contributed significantly to growth prediction even in the presence of tree size, stand density, and the distance-independent size ratio and crown ratio indices. Further, APA had the highest partial correlation when all variables were included in this multiple correlation. It was concluded the APA would be a good index for growth prediction models when other tree and stand attributes are already known.

scholarly journals I. Early Loblolly Pine Stand Response to Tillage on the Piedmont and Upper Coastal Plain of Georgia: Mortality, Stand Uniformity, and Second and Third Year Growth

2002 ◽  
Vol 26 (4) ◽  
pp. 181-189 ◽  
Author(s):  
R.E. Will ◽  
M.J. Wheeler ◽  
D. Markewitz ◽  
M.A. Jacobson ◽  
A.M. Shirley
Keyword(s):  
Loblolly Pine ◽  
Coastal Plain ◽  
Growing Season ◽  
Tree Size ◽  
Soil Tillage ◽  
Volume Index ◽  
Soil Series ◽  
Individual Tree ◽  
The Third ◽  
No Till

Abstract The effects of machine planting, disking, bedding, and bedding + subsoiling on growth of loblolly pine (Pinus taeda L.) were assessed after two and three growing seasons for seven contrasting sites on the Piedmont and Upper Coastal Plain of Georgia. Heights and groundline diameters of half the trees (50 trees) per plot, percent mortality, individual tree volume index (D2H), stand uniformity, and per hectare volume index were compared across sites and treatments. Average tree size of the treatments were ranked (from largest to smallest) bed, bed + subsoil, disk, machine, and no-till. At the end of the third growing season, the trees in the bed only treatment had a mean height, groundline diameter, and volume index of 2.3 m ± 0.06 SE, 59 mm ± 1.7 SE, and 0.0094 m3 ± 0.00066 SE, respectively. The trees of the no-till treatment had a mean height, groundline diameter, and volume index of 2.1 m ± 0.07 SE, 50 mm ± 1.6 SE, and 0.0063 3 ± 0.00056 SE, respectively. Overall, the disk, bed, and bed + subsoil treatment plots had significantly greater absolute volume growth during the third growing season than the no-till and machine plots. Most of the tree mortality within all treatments occurred during the first growing season with the disk treatment having the least mortality (13.6%) and the no-till treatment the most (24.9%). Stand height and diameter uniformity, examined using the within plot coefficient of variation, was not significantly different among treatments. Per hectare volume index was significantly greater for the bed (7.0 m3/ha) and bed + subsoil treatments (7.1 m3/ha) than for the no-till (4.5 m3/ha) and machine (5.2 m3/ha) treatments. Significant differences occurred between sites for tree size parameters, ranging between 2.7 m mean height and 64 mm mean groundline diameter for a site on a Cowarts soil series to 1.8 m mean height and 45 mm mean groundline diameter for trees growing on a Pacolet soil series. Significant interactions between tillage treatments and sites occurred for some tree size parameters at age 2, but not age 3, and for average plot mortality rate. The results of this study indicate that some early gains in tree growth can be achieved through soil tillage on upland sites. Bedding provided the most consistent, positive response, but adding subsoiling to bedding provided no benefit. Overall, the gains were relatively small and site dependent. Tillage on these Piedmont and Upper Coastal Plain soils should best be considered as part of a complete management program that includes to weed control and fertilization. South. J. Appl. For. 26(4):181–189.

Effects of competitor spacing in individual-tree indices of competition

2001 ◽  
Vol 31 (12) ◽  
pp. 2143-2150 ◽  
Author(s):  
Thomas Ledermann ◽  
Albert R Stage
Keyword(s):  
Prediction Model ◽  
Tree Size ◽  
Distance Functions ◽  
Individual Tree ◽  
Growth Prediction ◽  
Graphical Displays ◽  
Functional Forms ◽  
The Many

All indices of competition represent effects of distance between competing trees. However, the functional forms of these distance relations differ, because distance interacts with tree size in the many of the indices. In particular, some of the newer indices use vertical angles and crown geometry to define the effect of separation implicitly. Graphical displays showing effects of distance between subject tree and a competitor in published distance-dependent indices of competition are presented to permit visual comparisons of the indices. Nine pairs of subject and competitor crown classes are included for each index. Relation of these distance functions to the function implicit in distance-independent (stand-level) variables included in the growth prediction model is discussed.

Toward developing a direct relation between gross volume increment and stand density

2013 ◽  
Vol 43 (9) ◽  
pp. 852-860 ◽  
Author(s):  
Thomas J. Dean ◽  
Scott D. Roberts ◽  
Robert S. Seymour
Keyword(s):  
Loblolly Pine ◽  
Stand Density ◽  
Height Increment ◽  
Individual Tree ◽  
Red Alder ◽  
Quadratic Mean ◽  
Stem Size ◽  
Mean Diameter ◽  
Volume Increment ◽  
Quadratic Mean Diameter

A general form for expressing gross volume increment in terms of stand density is derived and tested with data from spacing trials in red alder (Alnus rubra Bong.), eastern white pine (Pinus strobus L.), longleaf pine (Pinus palustris Mill.), and loblolly pine (Pinus taeda L.). The equation relates the stand sum of individual-tree volume increment per metre height increment to a power function of quadratic mean diameter times tree density. The proposed equation fit the data best when the model included an intercept. Within each species, the fits were unbiased with respect to the independent variables, plantation age, and site height, and with the exception of the youngest ages for red alder and loblolly pine, they were unbiased with respect to the plot sums of individual-tree volume increment divided by individual height increment. Exponents estimated for quadratic mean diameter for each species ranged from 1.58 to 1.80. The resulting equations indicate a linear relationship between the stand sum of individual-tree volume increment per metre height increment and stand density. Scattergrams of gross-volume increment per hectare per year and stand density can be recovered by multiplying the predicted values of the regressions by Lorey’s height. The regressions support the hypothesis that each metre of height growth produces consistent changes in stem size, regardless of initial tree size, age, or site quality, and implies that the change in stem size is a predictable power function of stem diameter for an individual tree or quadratic mean diameter for a stand.

Using disaggregation to link individual-tree and whole-stand growth models

2006 ◽  
Vol 36 (4) ◽  
pp. 953-960 ◽  
Author(s):  
Jianhua Qin ◽  
Quang V Cao
Keyword(s):  
Loblolly Pine ◽  
Growth Models ◽  
Basal Area ◽  
Tree Model ◽  
Individual Tree ◽  
Stand Growth ◽  
Individual Tree Model ◽  
Stand Attributes ◽  
Pinus Taeda L ◽  
The Individual

Data from 200 plots randomly selected from the Southwide Pine Seed Source Study of loblolly pine (Pinus taeda L.) were used to fit whole-stand and individual-tree equations. Another 100 plots, also randomly selected, were used for validation. Outputs from the individual-tree model were then adjusted to match observed stand attributes (number of trees, basal area, and volume per hectare) by four disaggregation methods: proportional yield, proportional growth, constrained least squares, and coefficient adjustment. The first three are existing methods, and the fourth is new. The four methods produced similar results, and the coefficient adjustment was then selected as the method to disaggregate predicted stand growth among trees in the tree list. Results showed that, compared to the unadjusted individual tree model, the adjusted tree model performed much better in predicting stand attributes, while providing comparable predictions of tree diameter, height, and survival probability. The proposed approach showed promise in the ongoing effort to link growth models having different resolutions.

Long-term effects of stand density management and genotype on wood properties of loblolly pine (Pinus taeda L.) in the mid-South USA

2021 ◽  
Vol 491 ◽  
pp. 119176
Author(s):  
Michael A. Blazier ◽  
Thomas Hennessey ◽  
Laurence Schimleck ◽  
Scott Abbey ◽  
Ryan Holbrook ◽  
...  
Keyword(s):  
Pinus Taeda ◽  
Loblolly Pine ◽  
Stand Density ◽  
Wood Properties ◽  
Long Term Effects ◽  
Stand Density Management ◽  
Pinus Taeda L

Estimating individual tree leaf area in loblolly pine plantations using LiDAR-derived measurements of height and crown dimensions

2005 ◽  
Vol 213 (1-3) ◽  
pp. 54-70 ◽  
Author(s):  
Scott D. Roberts ◽  
Thomas J. Dean ◽  
David L. Evans ◽  
John W. McCombs ◽  
Richard L. Harrington ◽  
...  
Keyword(s):  
Leaf Area ◽  
Loblolly Pine ◽  
Pine Plantations ◽  
Individual Tree ◽  
Tree Leaf ◽  
Crown Dimensions

A New Index Representing Individual Tree Competitive Status

1973 ◽  
Vol 3 (4) ◽  
pp. 495-500 ◽  
Author(s):  
James A. Moore ◽  
Carl A. Budelsky ◽  
Richard C. Schlesinger
Keyword(s):  
Spatial Distribution ◽  
Strong Correlation ◽  
Basal Area ◽  
Tree Size ◽  
Competition Index ◽  
Individual Tree ◽  
Silvicultural Practices ◽  
Basal Area Growth ◽  
Hardwood Species ◽  
Area Growth

A new competition index, modified Area Potentially Available (APA), was tested in a complex unevenaged stand composed of 19 different hardwood species. APA considers tree size, spatial distribution, and distance relationships in quantifying intertree competition and exhibits a strong correlation with individual tree basal area growth. The most important characteristic of APA is its potential for evaluating silvicultural practices.

scholarly journals Influence of individual tree and stand attributes in stem straightness inPinus pinasterAit. stands

2004 ◽  
Vol 61 (2) ◽  
pp. 141-148 ◽  
Author(s):  
Miren del Río ◽  
Felipe Bravo ◽  
Valentín Pando ◽  
Gemma Sanz ◽  
Rosario Sierra de Grado
Keyword(s):  
Individual Tree ◽  
Stem Straightness ◽  
Stand Attributes

scholarly journals Stand structure links up canopy processes and forest management

2009 ◽  
Vol 51 (1) ◽  
pp. 40-48
Author(s):  
Toomas Frey
Keyword(s):  
Forest Management ◽  
Stand Structure ◽  
Net Primary Production ◽  
Stand Density ◽  
Tree Height ◽  
Belowground Biomass ◽  
Unit Mass ◽  
Total Biomass ◽  
Individual Tree ◽  
Mean Values

Stand structure links up canopy processes and forest management Above- and belowground biomass and net primary production (Pn) of a maturing Norway spruce (Picea abies (L.) Karst.) forest (80 years old) established on brown soil in central Estonia were 227, 50 and 19.3 Mg ha correspondingly. Stand structure is determined mostly by mean height and stand density, used widely in forestry, but both are difficult to measure with high precision in respect of canopy processes in individual trees. However, trunk form quotient (q2) and proportion of living crown in relation to tree height are useful parameters allowing describe stand structure tree by tree. Based on 7 model trees, leaf unit mass assimilation activity and total biomass respiration per unit mass were determined graphically as mean values for the whole tree growth during 80 years of age. There are still several possible approaches not used carefully enough to integrate experimental work at instrumented towers with actual forestry measurement. Dependence of physiological characteristics on individual tree parameters is the missing link between canopy processes and forest management.

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