scholarly journals Optimizing a Combination of Thinning Methods, Thinning Intensity and Timing Using a Stand Growth Simulation Model for Toyama Prefecture

FORMATH ◽  
2009 ◽  
Vol 8 (0) ◽  
pp. 121-136
Author(s):  
M. Konoshima ◽  
A. Yoshimoto ◽  
A. Kato
Keyword(s):  
Simulation Model ◽  
Growth Simulation ◽  
Stand Growth ◽  
Thinning Intensity

Actual and projected growth and yields of Populus 'Tristis #1' under intensive culture

1976 ◽  
Vol 6 (2) ◽  
pp. 132-144 ◽  
Author(s):  
Alan R. Ek ◽  
David H. Dawson
Keyword(s):  
Simulation Model ◽  
Tree Growth ◽  
Dry Weight ◽  
Intensive Culture ◽  
Annual Increment ◽  
Growth Simulation ◽  
Stand Growth ◽  
Mean Annual Increment ◽  
Stand Characteristics ◽  
Branch Wood

Yields and related stand characteristics of Populus 'Tristis #1' cuttings based on 4 years of growth under intensive culture (fertilization and irrigation) at square spacings of 0.75, 1, and 2 ft (0.23, 0.30 and 0.61 m) in northern Wisconsin are reported. Stem and branch wood yields were 40 390, 45 132, and 27 567 lb/acre (45 272, 50 586, and 30 899 kg/ha) for these spacings, and current annual increment peaked at age 3 for the 0.75- and 1-ft spacings. Tree growth and competition information from these plots was then used to calibrate a stand growth simulation model to develop yield projections to the 10- to 25-year range for the above plus 4-, 8-, and 12.7-ft (1.22-, 2.44-, and 3.87-m) spacings. Mean annual increment in terms of stem and branch wood dry weight for the projections peaked at about 8–15 years for all six spacings with values in the range of 13 881 – 16 584 lb/acre (15 559 – 18 588 kg/ha), respectively. The maximum mean annual increment was obtained at age 15 with a 4-ft spacing. Results further indicate substantial product-oriented flexibility in the choice of spacings and rotation ages since curves of mean annual increment are both similar and relatively flat in the 10- to 20-year range, except for the two widest spacings. A discussion of stand model projection methodology, reliability, and limitations is presented along with suggestions for more refined projections.

Modelling stand growth of radiata pine thinned to varying densities

1990 ◽  
Vol 20 (7) ◽  
pp. 1069-1076 ◽  
Author(s):  
A. G. D. Whyte ◽  
R. C. Woollons
Keyword(s):  
Negative Selection ◽  
Block Design ◽  
Basal Area ◽  
Radiata Pine ◽  
Projection Model ◽  
Stand Growth ◽  
Thinning Intensity ◽  
Randomized Complete Block Design ◽  
Attainable Yield ◽  
Similar Yield

Growth trends in a radiata pine thinning experiment established 18 years ago in Kaingaroa Forest, New Zealand, are portrayed and analyzed. The six thinnings, to 200, 300, 400, 500, 600, and 700/ha, were carried out at age 7 years; four replicates of each thinning level were laid out in 0.2 ha plots in a randomized complete block design. The dbh outside bark of all trees and the heights of a sample of 12–15 trees per 0.1 ha inner plot were remeasured at least once each year up to age 20 and then at 2-year intervals thereafter. Mean top-height development after age 7 years was little affected by thinning intensity, although initial negative selection may have reduced the subsequent vigour of the most heavily thinned plots. Analysis of a Gompertz projection model for net basal area per hectare and a similar yield formulation indicated that thinning down to 300/ha progressively lowered basal-area production and the maximum attainable yield but did not impair the ability to capture fully the available growing space. The 200/ha treatment, however, was much impaired, and its asymptote was lowered to such an extent that its yield trajectory was continuing to fall away relative to the others. The analysis quantifies this reduction and could possibly allow estimates of how much production would be lost between 200 and 300/ha, so that due allowance could be made when predicting yields for routine thinning prescriptions within that range.

Plot Edge Bias in Forest Stand Growth Simulation Models

1974 ◽  
Vol 4 (4) ◽  
pp. 419-423 ◽  
Author(s):  
Robert A. Monserud ◽  
Alan R. Ek
Keyword(s):  
Spatial Pattern ◽  
Spatial Patterns ◽  
Simulation Models ◽  
Bias Reduction ◽  
Forest Stand ◽  
Tree Size ◽  
Individual Tree ◽  
Growth Simulation ◽  
Relative Simplicity ◽  
Stand Growth

The problem of edge bias arising in the computation of individual tree competition in stand growth simulation models is discussed. The problem arises from difficulty in characterizing tree size and spatial patterns beyond the edge of the simulation plot. Various methods for reducing this bias are reviewed along with related assumptions and major sources of error. Methods which involve shifting the simulation plot image to form a set of border plots are judged best on the basis of likely bias reduction and the relative simplicity of introduced spatial pattern periodicity.

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