Effects of thinning and urea fertilization on the distribution of area increment along the boles of Douglas-fir at Shawnigan Lake, British Columbia

1984 ◽  
Vol 14 (6) ◽  
pp. 879-884 ◽  
Author(s):  
A. J. Thomson ◽  
H. J. Barclay

The effects of fertilization and thinning of Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) on the distribution of area increment along the bole were assessed using radial growth measurements 6 and 9 years after treatment. Within treatments, the average area increment per tree was linearly related to diameter at breast height, and this relationship was used to evaluate the effects of treatment on growth rate. Fertilization had the greatest effect on average area increment, and for a particular fertilization regime, thinning increased the response. Thinning modified the distribution of growth over the bole of all trees and increased butt flare, especially in smaller trees. The effect declined from the 4- to 6-year measurement period to the 7-to 9-year measurement period. Fertilization had no consistent effect on growth distribution. The regression methods used in this study provided a more sensitive measure of form changes than previous methods, were independent of size distribution, and facilitated extrapolations and evaluation of temporal trend.

1966 ◽  
Vol 44 (4) ◽  
pp. 453-466 ◽  
Author(s):  
J. H. G. Smith ◽  
L. Heger ◽  
J. Hejjas

Widths of earlywood and latewood in each annual ring, measured on an average radius on a disk taken halfway between each branch whorl, were analyzed to define their variation in 18 Douglas-fir trees (Pseudotsuga menziesii (Mirb.) Franco). Distribution of ring width and percentage latewood also was investigated in these trees which had from 20 to 50 whorls above stump height. Multiple regression and correlation analyses showed that number of rings from pith, and its reciprocal, square, or logarithm accounted for most of the variation in radial growth. Number of rings from pith influenced thickness of both earlywood and latewood much more than the climatic differences reflected by variations in annual height growth and in widths of earlywood and latewood formed at breast height in the same calendar year. Since earlywood and latewood are distributed differently and controlled by different factors, they should be studied separately within annual rings. The statistical methods used in this study provide a simple, efficient, and comprehensive basis for thoroughly describing growth patterns, and for objectively analyzing factors that govern growth.


2001 ◽  
Vol 31 (10) ◽  
pp. 1691-1700 ◽  
Author(s):  
Zhong Chen ◽  
Thomas E Kolb ◽  
Karen M Clancy ◽  
Valerie D Hipkins ◽  
Laura E DeWald

We used starch gel electrophoresis to investigate levels of genetic variation between trees of interior Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco var. glauca) that were phenotypically resistant versus susceptible to defoliation by the western spruce budworm (Choristoneura occidentalis Freeman). We also investigated the association between allozyme variation and tree growth traits. Overall, the phenotypically resistant trees had a lower allelic heterozygosity (p = 0.020) compared with susceptible trees. However, this difference between resistant and susceptible trees primarily occurred at the Buena Vista, Colorado, site rather than the Deckers, Colorado, and Jacob Lake, Arizona, sites. Among 25 loci we examined, the resistant trees also had a higher frequency of the most common alleles (p = 0.057) and a higher proportion of homozygous genotypes, especially at loci FEST-1 (p = 0.004), ACO-1 (p = 0.080), and 6PGD-1 (p = 0.084). The higher allelic heterozygosity in susceptible trees was mainly due to their higher proportion of uncommon and (or) rare alleles. Compared with susceptible trees, resistant trees had higher mean radial growth rates (p = 0.047) and less temporal variability in growth rate over 25 years (p = 0.037). Mean radial growth rate and average tree heterozygosity were not related at any site (p = 0.316). Relationships between temporal variability in growth rate and tree heterozygosity were inconsistent among sites. Our results suggest that phenotypic differences in resistance of interior Douglas-fir to western spruce budworm defoliation are partly caused by genetic differences among trees.


2014 ◽  
Vol 60 (No. 7) ◽  
pp. 288-296 ◽  
Author(s):  
K. Petkova ◽  
M. Georgieva ◽  
M. Uzunov

A comparative analysis of growth rate and health condition of 54 Douglas-fir (Pseudotsuga menziesii [Mirb.] Franco) provenances was conducted at the age of 24 years. The provenance test was established in 1990 with 3-year-old (3+0) seedlings planted in a 2 × 2 m plot design and two replications. The provenances which were studied originated from North America and were separated into coastal, continental and Western Cascade groups. In 2011 the growth rate was studied in terms of height, diameter at breast height and stem volume. The health condition was assessed by the evidence of symptoms and degree of defoliation caused by the fungi Phaeocryptopus gaeumannii (Rohde) Petrak and Rhabdocline pseudotsugae (Syd.). The provenances Newhalem, Darrington, Idanha and Bremerton were characterized by the most rapid growth, highest productivity and lower susceptibility to both fungal pathogens. These Douglas-fir provenances were recommended for future afforestation in Bulgaria. Ten continental provenances should be excluded from future afforestation because of their lowest growth rate and productivity and high susceptibility to P. gaeumannii and R. pseudotsugae.  


2012 ◽  
Vol 163 (3) ◽  
pp. 96-104 ◽  
Author(s):  
Joachim Klädtke ◽  
Ulrich Kohnle ◽  
Edgar Kublin ◽  
Andreas Ehring ◽  
Hans Pretzsch ◽  
...  

Growth and value production of Douglas-fir under varying stand densities The investigation is focused on the effects of initial tree number and thinning on growth and value performance of Douglas-fir stands. Data base is a coordinated Douglas-fir spacing experiment in South Germany, started 40 years ago and comprising variants of tree numbers with 500, 1,000, 2,000 and 4,000 Douglas-firs per hectare. The treatment was performed according to a standardized experiment program. The results show that at low initial tree numbers, the diameter on breast height (DBH) of (pre)dominant trees at the beginning of the observations (with 12 m top height) is bigger than at higher initial plant numbers. Accordingly, the quotient of height (H) to DBH (as an indicator for tree's static stability) is lower. The further development of DBH and H/DBH quotient is decisively determined by stand treatment, which superimposes the effect of the initial tree number. The total volume growth shows a clear differentiation, too, the variants with initially high tree numbers appearing on top. In the monetary analysis, this ranking is reversed: despite a supposed inferior wood quality, the variants with lower initial tree numbers clearly outperform the ones with higher numbers in terms of value. From these results, the following silvicultural recommendations for Douglas-fir can be derived: the initial tree numbers should be in the range from 1,000 to 2,000 plants per hectare. On technically not accessible sites, even lower tree numbers may come into question. The strong influence of stand treatment on DBH and H/DBH development highlights the problem of postponed thinnings, for this causes growth and stability losses even under favorable starting conditions in terms of competition.


2020 ◽  
Vol 13 (7) ◽  
pp. 754-760
Author(s):  
V. G. Soukhovolsky ◽  
P. A. Krasnoperova ◽  
E. N. Pal’nikova ◽  
I. V. Sviderskaya ◽  
O. V. Tarasova

Author(s):  
Anirbit Sengupta ◽  
Anwesha Mukherjee ◽  
Abhijit Das ◽  
Debashis De

IAWA Journal ◽  
1997 ◽  
Vol 18 (1) ◽  
pp. 53-67 ◽  
Author(s):  
Ingrid de Kort ◽  
Pieter Baas

Ring width patterns often different stands, five vitality classes and three age-classes are used to explore the effect of the decline in vitality on radial growth of Douglas fir in the Netherlands and to determine the onset of this decline. A relationship between growth performance and crown vitality is found in most stands, although the variation within and between stands is large. Severe needle loss leads to serious decline in ring width. The onset of the decline varies from c. 1959 to 1976. The present data set does not enable a choice between the various causal scenarios of forest decline that have been proposed in the literature.


2003 ◽  
Vol 186 (1-3) ◽  
pp. 257-260 ◽  
Author(s):  
Adam M. Taylor ◽  
Barbara L. Gartner ◽  
Jeffrey J. Morrell
Keyword(s):  

2020 ◽  
Vol 66 (3) ◽  
pp. 275-283 ◽  
Author(s):  
Halli Hemingway ◽  
Mark Kimsey

Abstract Accurate measures of forest site productivity are essential for forest-management planning. The most common measure of site productivity is breast height–age site index (BHASI)—the expected height at a reference age. Error from including early growth in productivity estimates and limited applicability of any one BHASI model warrant development of alternative methods. Exploring alternatives may only be necessary if regional BHASI models are not accurately predicting growth rates. We compared modeled height growth rates for Rocky Mountain Douglas-fir (Pseudotsuga menziesii var. glauca) to felled-tree measurements to evaluate relative performance of a regional BHASI model. An orthogonal sampling design ensured samples were collected across a range of site factors known to influence Douglas-fir growth rates. Growth rates for each 10 m section were calculated and compared to BHASI modeled growth rates. The regional BHASI model underpredicted growth rates from breast height to 30 m. Observed growth rates from 10 to 30 m accounted for the majority of underprediction relative to BHASI modeled growth rates. An alternative multipoint method of defining site productivity is described. More research comparing BHASI and alternative methods is needed, given the growth rate error associated with one-point site productivity assessment.


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