scholarly journals Managing plantation density through initial spacing and commercial thinning: Yield results from a 60-year-old red pine spacing trial experiment

2020 ◽  
Author(s):  
Nelson Thiffault ◽  
Michael K. Hoepting ◽  
Jeff Fera ◽  
Jean-Martin Lussier ◽  
Guy R. Larocque
Keyword(s):  
Basal Area ◽  
Pinus Resinosa ◽  
Stand Volume ◽  
Quadratic Mean ◽  
Commercial Thinning ◽  
Volume Yield ◽  
Volume Production ◽  
Initial Spacing ◽  
Quadratic Mean Diameter ◽  
Common Target

We report on a 60-year-old Pinus resinosa spacing trial experiment located in Ontario (Canada) that included the combinations between six initial spacings (from 1.2–3.0 m) and the presence/absence of a commercial thinning (CT) regime, and their impacts on quadratic mean diameter (QMD) and stand volume yield. The CT regime, initiated at age 30, targeted a residual basal area (BA) of 38 m2 ha-1 after each of four entries. Without thinning, as initial spacing increased, QMD increased; gross and net volume production peaked in the 2.1–2.4 m spacings. With thinning, similar trends with spacing were evident for QMD, although piece sizes were larger and differences between spacing were lower. The immediate increase of average tree size caused by tree selection explained most of the differences in QMD between thinned and unthinned plots. Thinning to a common target BA resulted in similar standing volume across spacings. Cumulative gross yield was similar between spacings <2.1 m for both unthinned/thinned stands and decreased for thinned plots for wider spacings. Greater net volume production in thinned stands with the narrower spacings confirmed that mortality was captured. Lower gross and net production for wider spacings suggested that thinning resulted in under-utilized growing space.

Pinus resinosa product potential following initial spacing and subsequent thinning

2001 ◽  
Vol 77 (1) ◽  
pp. 129-139 ◽  
Author(s):  
M. Penner ◽  
C. Robinson ◽  
D. Burgess
Keyword(s):  
Basal Area ◽  
Pinus Resinosa ◽  
Red Pine ◽  
Good Growth ◽  
Thinning Intensity ◽  
Utility Pole ◽  
Volume Production ◽  
Initial Spacing ◽  
High Utility ◽  
Time Required

A trial was initiated in 1953 to investigate the effect of initial tree spacing on red pine (Pinus resinosa Ait.) volume production. Approximately three decades later, in 1982, thinning treatments were added to compare the effects of thinning and initial spacing on volume production. After 45 growing seasons from planting, total volume production (cut + standing volume) mainly was independent of initial spacing and thinning intensity except at the widest (4.3 m +) spacing treatments. Both initial spacing and thinning affected quadratic mean diameter, standing volume and basal area. Knot size was affected by initial spacing with trees at an initial spacing of 3.0 m or wider having a significant number of stems failing to meet utility pole standards due to excessive, large knots. At the time of sampling, 1998, the higher initial densities (1.2 and 1.5 m-spacing) were undergoing significant mortality and falling behind the lower initial spacings in terms of total volume production. In addition, trees at the narrowest spacing were more prone to snow and ice damage. Thinning reduced the time required to meet sawlog and utility pole specifications. The initial spacings ranging from 1.8 to 2.4 m resulted in good growth with high utility pole potential and little mortality. Lower initial spacings required thinning to prevent mortality and maintain good diameter growth. Key words: red pine, density management, volume production, product mixtures

scholarly journals Modeling Dynamics of Structural Components of Forest Stands Based on Trivariate Stochastic Differential Equation

Forests ◽  
2019 ◽  
Vol 10 (6) ◽  
pp. 506 ◽  
Author(s):  
Petras Rupšys
Keyword(s):  
Differential Equation ◽  
Basal Area ◽  
Growth And Yield ◽  
Mixed Effect ◽  
Stand Volume ◽  
Quadratic Mean ◽  
Stand Growth ◽  
Mean Diameter ◽  
Quadratic Mean Diameter ◽  
Stand Basal Area

Research Highlights: Today’s approaches to modeling of forest stands are in most cases based on that the regression models and they are constructed as static sub-models describing individual stands variables. The disadvantages of this method; it is laborious because too many different equations need to be assessed and empirical choices of candidate equations make the results subjective; it does not relate to the stand variables dynamics against the age dimension (time); and does not consider the underlying covariance structure driving changes in the stand variables. In this study, the dynamical model defined by a fixed-and mixed effect parameters trivariate stochastic differential equation (SDE) is introduced and described how such a model can be used to model quadratic mean diameter, mean height, number of trees per hectare, self-thinning line, stand basal area, stand volume per hectare and much more. Background and Objectives: New developed marginal and conditional trivariate probability density functions, combining information generated from an age-dependent variance-covariance matrix of quadratic mean diameter, mean height and number of trees per hectare, improve stand growth prediction, and forecast (in forecast the future is completely unavailable and must only be estimated from historical patterns) accuracies. Materials and Methods: Fixed-and mixed effect parameters SDE models were harmonized to predict and forecast the dynamics of quadratic mean diameter, mean height, number of trees per hectare, basal area, stand volume per hectare, and their current and mean increments. The results and experience from applying the SDE concepts and techniques in an extensive whole stand growth and yield analysis are described using a Scots pine (Pinus sylvestris L.) experimental dataset in Lithuania. Results: The mixed effects scenario SDE model showed high accuracy, the percentage root mean square error values for quadratic mean diameter, mean height, number of trees per hectare, stand basal area and stand volume per hectare predictions (forecasts) were 3.37% (10.44%), 1.82% (2.07%), 1.76% (2.93%), 6.65% (10.41%) and 6.50% (8.93%), respectively. In the same way, the quadratic mean diameter, mean height, number of trees per hectare, stand basal area and stand volume per hectare prediction (forecast) relationships had high values of the coefficient of determination, R2, 0.998 (0.987), 0.997 (0.992), 0.997 (0.988), 0.968 (0.984) and 0.966 (0.980), respectively. Conclusions: The approach presented in this paper can be used for developing a new generation stand growth and yield models.

Silvicultural responses of two spruce plantations to midrotation commercial thinning in New Brunswick

2008 ◽  
Vol 38 (4) ◽  
pp. 851-867 ◽  
Author(s):  
Gaetan Pelletier ◽  
Douglas G. Pitt
Keyword(s):  
Volume Growth ◽  
Basal Area ◽  
Early Age ◽  
Quadratic Mean ◽  
Selection Strategies ◽  
Commercial Thinning ◽  
Single Entry ◽  
Number Of Stems ◽  
Quadratic Mean Diameter ◽  
Observation Period

A midrotation commercial thinning experiment conducted in two independent spruce plantations compared several tree selection strategies as both early (age 19 or 24 years) single and double (again at age 30 or 34 years) entries over a 16 year period. A delayed (age 30 or 32 years) single-entry thinning and unthinned portions of the plantations served as references for the other treatments. With the exception of 50% systematic row thinnings, removal intensities were held relatively constant at about 40% of stand basal area. All of the thinning treatments satisfied the objectives of focusing diameter and volume growth on a reduced number of stems and making merchantable volume available during the rotation. Early single-entry thinning allowed 30–50 m3/ha to be harvested, increasing quadratic mean diameter and mean merchantable volume per stem at the end of the observation period by 10% and 24%, respectively, over unthinned stands. A second thinning removed an additional 48–64 m3/ha and increased diameter and volume gains to 25% and 71%, respectively. Only marginal differences were observed between the tree-selection strategies, and there were no overall gross total or gross merchantable volume gains or losses associated any of the thinning treatments relative to the unthinned plantations.

A Stocking Guide for Southern Bottomland Hardwoods

1995 ◽  
Vol 19 (3) ◽  
pp. 103-104 ◽  
Author(s):  
J. C. G. Goelz
Keyword(s):  
Basal Area ◽  
Bottomland Hardwoods ◽  
Quadratic Mean ◽  
Mean Diameter ◽  
Quadratic Mean Diameter

Abstract A stocking guide was developed from the data of Putnam, et al. (1960). The form of the stocking guide follows Gingrich (1967), although the “B”-line is based on the suggested residual stocking of Putnam, et al. (1960) rather than on minimum full stocking. This stocking guide is similar to the stocking guide for central upland hardwoods constructed by Gingrich, except that 100% stocking is 5-7 ft2² of basal area lower for the southern bottomland guide, across a range of quadratic mean diameter. South. J. Appl. For. 19(3):103-104.

Compatible basal-area growth and yield model for thinned and unthinned stands

1983 ◽  
Vol 13 (4) ◽  
pp. 563-571 ◽  
Author(s):  
Robert L. Bailey ◽  
Kenneth D. Ware
Keyword(s):  
Loblolly Pine ◽  
Basal Area ◽  
Growth And Yield ◽  
Yield Model ◽  
Projection Model ◽  
Quadratic Mean ◽  
Basal Area Growth ◽  
Area Growth ◽  
Mean Diameter ◽  
Quadratic Mean Diameter

A measure of kind and level of thinning is developed and its relationship to other stand attributes such as number of trees, basal area, and volume removed in thinning is quantified. This measure or thinning index is based on the ratio of the quadratic mean diameter of thinned trees to the quadratic mean diameter of all trees before thinning. The thinning index is then logically incorporated into a thinning multiplier from which is derived a compatible basal-area growth projection model to generalize the previous concepts for thinning effects in systems for predicting growth and yield. Empirical tests with data from thinned and unthinned natural stands of loblolly pine, from thinned and unthinned slash pine plantations, and from thinned western larch stands show the model to provide estimates with improved properties. Hence, the thinning index and the thinning multiplier are also proposed for other situations involving effects of thinning.

Partial Calibration of "ONTWIGS": A Forest Growth and Yield Projection System Adapted for Ontario

1994 ◽  
Vol 11 (2) ◽  
pp. 41-46 ◽  
Author(s):  
Bijan Payandeh ◽  
Pia Papadopol
Keyword(s):  
Basal Area ◽  
Forest Growth ◽  
Data Sets ◽  
Prediction Errors ◽  
Northern Ontario ◽  
Quadratic Mean ◽  
Tree Survival ◽  
Mean Diameter ◽  
Quadratic Mean Diameter ◽  
Stand Attributes

Abstract "ONTWIGS" (an adaptation of "LSTWIGS" for Ontario), was partially calibrated for permanent plots data sets from northern Ontario. Stand attributes used for calibration were quadratic mean diameter, number of trees, and basal area/ha. Simple local calibration was accomplished by adjusting tree survival and potential diameter growth coefficients so as to reduce the prediction errors to within 10% of the actual values over a 5-yr period. This resulted in prediction errors ranging from -9.9 to 6.9%, but with an overall average of only: -1.4, 1.0, and 0.2% for the spruce fir data; from -8.5 to 2.8%, but with an overall average of only -0.7, 0.5, and 0.4% for a black spruce drainage and fertilization experiment; and from -6.6 to 9.8%, but with an overall average of only -1.7, 0.0, and -1.8% for an unthinned red pine plantation for number of trees/ha, quadratic mean diameter, and basal area/ha, respectively. Results indicate that "ONTWIGS" may be locally calibrated through simple procedures to increase its prediction accuracy to ±5% of the observed stand attributes, averaging less than 3% for the major timber species in northern Ontario and for short to medium projection periods. However, the uncalibrated model should be used with caution for short terms, only and where no other projection tools are available. More extensive calibrations of "ONTWIGS" on larger and more representative data sets are currently underway. North. J. Appl. For. 11(2):41-46.

scholarly journals Development of Water Tupelo Coppice Stands on the Mobile-Tensaw River Delta for Five Years After Precommercial Thinning and Cleaning

2001 ◽  
Vol 25 (4) ◽  
pp. 165-172 ◽  
Author(s):  
J.C.G. Goelz ◽  
J.S. Meadows ◽  
T.C. Fristoe
Keyword(s):  
Basal Area ◽  
Individual Tree ◽  
Quadratic Mean ◽  
Precommercial Thinning ◽  
Mean Diameter ◽  
Water Tupelo ◽  
Rotation Age ◽  
Large Water ◽  
Quadratic Mean Diameter ◽  
The Individual

Abstract Three 4-yr-old stands (or locations) were selected for treatment. Treatment consisted of two components: (1) thinning water tupelo (Nyssa aquatica L.) stump sprouts and (2) cutting all stems of Carolina ash (Fraxinus caroliniana Mill.) and black willow (Salix nigra Marsh.) (cleaning). Contrary to results in other areas, survival of water tupelo coppice was very high and was not affected by the treatments. Cleaning had little or no positive effect on the individual tree or stand-level variables we measured. Thinning sprout clumps significantly increased diameter growth of water tupelo; the effect of thinning was considerably larger for one location. Stand basal area growth was decreased by thinning sprout clumps. However, quadratic mean diameter was increased by thinning, particularly at one location. Although thinning decreased basal area 5 yr after treatment, the increase in quadratic mean diameter was sufficient for there to be no significant effect of thinning on total volume 5 yr after treatment. Because of this, and in anticipation of imminent natural thinning of the unthinned plots, we suspect that the thinned plots will eventually have significantly greater standing volume than the unthinned plots, at least for the location where density of large sprouts was initially the highest. Rotation age will be decreased for that stand because stems will achieve merchantable size sooner. Thus we consider precommercial thinning of sprout clumps to be a potentially effective practice in stands with a high density of large water tupelo sprouts. South. J. Appl. For. 25(4):165–172.

Algorithmic versions of black spruce stand density management diagrams

1997 ◽  
Vol 73 (2) ◽  
pp. 257-265 ◽  
Author(s):  
P. F. Newton
Keyword(s):  
Black Spruce ◽  
Initial Density ◽  
Basal Area ◽  
Stand Density ◽  
File Transfer ◽  
Quadratic Mean ◽  
Dominant Height ◽  
Yield Production ◽  
Quadratic Mean Diameter ◽  
Stand Density Management

Algorithmic versions of stand density management diagrams (SDMDs) were developed for natural and managed black spruce (Picea mariana (Mill.) B.S.P.) stands. Specifically, the IBM-compatible PC-based algorithms (1) graphically illustrate site-specific size-density trajectories for eight user-specified initial density regimes, (2) given (1), calculate and subsequent tabulate periodic yield estimates (mean dominant height, density, mean volume, total volume, total merchantable volume, quadratic mean diameter, and basal area), and (3) given (2), graphically illustrate empirically-derived yield production curves for total merchantable volume ha−1 and stems m−3 with user-specified operability criteria superimposed. Instructions on acquiring the executable algorithmic versions including the required graphical subroutines via the Internet are described. Currently, the algorithms are restricted in applicability to central insular Newfoundland. Key words: stand density management diagrams, black spruce, algorithms, microcomputer, World-Wide Web (WWW), hypertext browser, file transfer protocol (FTP).

scholarly journals Relating Forest Attributes with Area- and Tree-Based Light Detection and Ranging Metrics for Western Oregon

2010 ◽  
Vol 25 (3) ◽  
pp. 105-111 ◽  
Author(s):  
Michael E. Goerndt ◽  
Vincente J. Monleon ◽  
Hailemariam Temesgen
Keyword(s):  
Basal Area ◽  
Light Detection And Ranging ◽  
Stem Volume ◽  
Height Distribution ◽  
Light Detection ◽  
Quadratic Mean ◽  
Crown Width ◽  
Mean Diameter ◽  
Forest Attributes ◽  
Quadratic Mean Diameter

Abstract Three sets of linear models were developed to predict several forest attributes, using stand-level and single-tree remote sensing (STRS) light detection and ranging (LiDAR) metrics as predictor variables. The first used only area-level metrics (ALM) associated with first-return height distribution, percentage of cover, and canopy transparency. The second alternative included metrics of first-return LiDAR intensity. The third alternative used area-level variables derived from STRS LiDAR metrics. The ALM model for Lorey's height did not change with inclusion of intensity and yielded the best results in terms of both model fit (adjusted R2 = 0.93) and cross-validated relative root mean squared error (RRMSE = 8.1%). The ALM model for density (stems per hectare) had the poorest precision initially (RRMSE = 39.3%), but it improved dramatically (RRMSE = 27.2%) when intensity metrics were included. The resulting RRMSE values of the ALM models excluding intensity for basal area, quadratic mean diameter, cubic stem volume, and average crown width were 20.7, 19.9, 30.7, and 17.1%, respectively. The STRS model for Lorey's height showed a 3% improvement in RRMSE over the ALM models. The STRS basal area and density models significantly underperformed compared with the ALM models, with RRMSE values of 31.6 and 47.2%, respectively. The performance of STRS models for crown width, volume, and quadratic mean diameter was comparable to that of the ALM models.

scholarly journals Stocking Diagrams for Silvicultural Guideline in Korean Pines and Japanese Larch

Forests ◽  
2020 ◽  
Vol 11 (8) ◽  
pp. 833
Author(s):  
Daesung Lee ◽  
Jungkee Choi
Keyword(s):  
Basal Area ◽  
Stand Density ◽  
Japanese Larch ◽  
Larix Kaempferi ◽  
White Pine ◽  
Individual Tree ◽  
Quadratic Mean ◽  
Mean Diameter ◽  
Quadratic Mean Diameter ◽  
Species Specific

Appropriate management of stand density is necessary to avoid wasted growing space and overcrowding-induced self-thinning and therefore to optimize profitability. We developed a Gingrich-style stocking chart for Korean red pine (Pinus densiflora), Korean white pine (P. koraiensis), and Japanese larch (Larix kaempferi) in Korea. Datasets for even-aged stands were categorized into two censored datasets via relative density based on species-specific stand density indices to assign adequate plots for tree allometry. Censored plot data for maximum density on full stocking were used to develop A-level stocking based on mean individual tree area. In censored plot data for minimum density on full stocking, individual trees represented open-grown trees, and a crown competition factor of 100 was proposed as B-level stocking. Based on parameters estimated from allometry, stocking diagrams comprising quadratic mean diameter, number of trees, and basal area were correctly expressed. A-level stocking at the same quadratic mean diameter revealed that Korean white pine had the most trees and largest basal area, while Japanese larch had the fewest trees and smallest basal area. In contrast, B-level stocking disclosed that Japanese larch had the most trees and basal area, whereas Korean white pine had the fewest trees and smallest basal area. The stocking diagrams suggest that silvicultural treatments for these species should be species-specific.

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