Diseases of Douglas fir (Pseudotsuga spp.)

1982 ◽  
pp. 173-179
Author(s):  
D. H. Phillips ◽  
D. A. Burdekin
Keyword(s):  
Douglas Fir

Mulching to regenerate a harsh site: effect on Douglas-fir seedlings, forbs, grasses, and ferns

1994 ◽  
Author(s):  
Philip M. McDonald ◽  
Gary O. Fiddler ◽  
Henry R. Harrison
Keyword(s):  
Site Effect ◽  
Douglas Fir

Effect of habitat-improvement thinnings on lumber products from coastal Douglas-fir

2016 ◽  
Author(s):  
Dennis P. Dykstra ◽  
Patricia K. Lebow ◽  
Stephen Pilkerton ◽  
Jamie Barbour ◽  
Susan Hummel ◽  
...  
Keyword(s):  
Douglas Fir ◽  
Habitat Improvement

Wachstum und Wertleistung der Douglasie in Abhängigkeit von der Standraumgestaltung

2012 ◽  
Vol 163 (3) ◽  
pp. 96-104 ◽  
Author(s):  
Joachim Klädtke ◽  
Ulrich Kohnle ◽  
Edgar Kublin ◽  
Andreas Ehring ◽  
Hans Pretzsch ◽  
...  
Keyword(s):  
Wood Quality ◽  
Volume Growth ◽  
Static Stability ◽  
Douglas Fir ◽  
Breast Height ◽  
Monetary Analysis ◽  
Starting Conditions ◽  
Tree Number ◽  
Clear Differentiation ◽  
Further Development

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.

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