Crop Rotation of Douglas-Fir and Red Alder: A Preliminary Biological and Economic Assessment

1979 ◽  
Vol 140 ◽  
pp. S102-S107 ◽  
Author(s):  
W. A. Atkinson ◽  
B. T. Bormann ◽  
D. S. de Bell
Keyword(s):  
Crop Rotation ◽  
Economic Assessment ◽  
Douglas Fir ◽  
Red Alder

Influence of Particle Size on Decomposition of Red Alder and Douglas Fir Sawdust in Soil

Nature ◽  
1965 ◽  
Vol 205 (4975) ◽  
pp. 991-993 ◽  
Author(s):  
J. L. NEAL ◽  
W. B. BOLLEN ◽  
K. C. LU
Keyword(s):  
Particle Size ◽  
Douglas Fir ◽  
Red Alder

The economics of Douglas-fir and red alder management with stochastic price trends

1993 ◽  
Vol 23 (8) ◽  
pp. 1695-1703 ◽  
Author(s):  
Robert G. Haight
Keyword(s):  
Pacific Northwest ◽  
Financial Analysis ◽  
Probability Distributions ◽  
Low Cost ◽  
The United States ◽  
Douglas Fir ◽  
Mixed Species ◽  
Red Alder ◽  
Commercial Thinning ◽  
Price Trends

A financial analysis of Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) and red alder (Alnusrubra Bong.) management is conducted using yield projections from the Stand Projection Simulator for the Pacific Northwest region of the United States. The analysis includes uncertainty in the price trends and stocking levels of both species following reforestation. Results from a case study in which Douglas-fir price is likely to increase faster than red alder price show that (i) on more productive sites, greater regeneration investment is justified to increase the likelihood of Douglas-fir establishment; (ii) on less productive sites, low-cost regeneration options that produce mixed-species stands have expected present values close to or greater than a high-cost Douglas-fir regeneration effort; (iii) optimal precommercial removal of red alder depends on midrotation prices and regeneration success, and in many cases growing a mixed-species stand to maturity produces the highest economic return; (iv) commercial thinning of Douglas-fir increases the expected present value of the most intensive regeneration option by up to 10%. The low-cost regeneration options have relatively high expected returns because of low initial investments and the presence of two species that may have high values in the future. The sensitivity of these results to changes in the probability distributions of regeneration success and price trends is discussed.

Spatial extent of impact of red alder on soil chemistry of adjacent conifer stands

1992 ◽  
Vol 22 (9) ◽  
pp. 1434-1437 ◽  
Author(s):  
Charles C. Rhoades ◽  
Dan Binkley
Keyword(s):  
Soil Ph ◽  
Soil Chemistry ◽  
Douglas Fir ◽  
Spatial Extent ◽  
N Availability ◽  
Soil N ◽  
Mixed Stands ◽  
Red Alder ◽  
Soil N Availability ◽  
River Site

We examined patterns in soil N availability and pH along transects extending from mixed stands of conifers (mostly Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco)) and red alder (Alnusrubra Bong.) to pure conifer stands at two locations. At the relatively infertile Wind River site, increased N availability was apparent for about 8–12 m downslope of the alder–conifer stand, but no effect was apparent upslope. At the fertile Cascade Head site, no trend was apparent in N availability across the stand boundaries, but soil pH in the conifer stand was depressed for about 5 m from the alder–conifer stand. Overall, the effects of alder on soil chemistry appeared limited to a distance of less than half the height of the trees.

Use of growth curve derivatives to illustrate acceleration and deceleration of growth in young plantations under variable competition

2006 ◽  
Vol 36 (10) ◽  
pp. 2515-2522 ◽  
Author(s):  
Michael Newton ◽  
Elizabeth C Cole
Keyword(s):  
Growth Period ◽  
Tsuga Heterophylla ◽  
Douglas Fir ◽  
Early Years ◽  
Western Hemlock ◽  
Richards Equation ◽  
Second Derivative ◽  
Red Alder ◽  
Vegetation Control ◽  
Second Derivatives

Deceleration of growth rates can give an indication of competition and the need for thinning in early years but can be difficult to detect. We computed the first and second derivatives of the von Bertalanffy – Richards equation to assess impacts of density and vegetation control in young plantations in western Oregon. The first derivative describes the response in growth and the second derivative describes the change in growth over time. Three sets of density experiments were used: (i) pure Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco), (ii) mixed Douglas-fir and grand fir (Abies grandis (Dougl. ex D. Don) Lindl.), and (iii) mixed western hemlock (Tsuga heterophylla (Raf.) Sarg.) and red alder (Alnus rubra Bong.). Original planting densities ranged from 475 to 85 470 trees·ha–1 (4.6 m × 4.6 m to 0.34 m × 0.34 m spacing); western hemlock and red alder plots were weeded and unweeded. For the highest densities, the second derivative was rarely above zero for any of the time periods, indicating that the planting densities were too high for tree growth to enter an exponential phase. As expected, the lower the density, the greater and later the peak in growth for both the first and second derivatives. Weeding increased the growth peaks, and peaks were reached earlier in weeded than in unweeded plots. Calculations of this sort may help modelers identify when modifiers for competition and density are needed in growth equations. Specific applications help define onset of competition, precise determining of timing of peak growth, period of acceleration of growth, and interaction of spacing and age in determination of peaks of increment or acceleration or deceleration.

Effects of species mixtures on growth and stand development of Douglas-fir and red alder

2006 ◽  
Vol 36 (3) ◽  
pp. 768-782 ◽  
Author(s):  
Steven R Radosevich ◽  
David E Hibbs ◽  
Claudio M Ghersa
Keyword(s):  
Pacific Northwest ◽  
Tree Mortality ◽  
Stand Structure ◽  
Stand Density ◽  
Douglas Fir ◽  
Forest Understory ◽  
Red Alder ◽  
Structure Tree ◽  
Species Proportions ◽  
Species Mixtures

In the Pacific Northwest, a mixture of Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) and red alder (Alnus rubra Bong.) often results when red alder regenerates naturally in planted conifer stands. The relationships among stand structure, tree mortality, tree size, and understory development in the two species mixtures were explored at two sites for the first 16 years after planting. Treatments included a range of species proportions, and red alder was either planted simultaneously with Douglas-fir or planting was delayed for 5 years. Red alder was also removed from some simultaneously planted proportions. Both replacement effects (total stand density held constant) and additive effects (stand density doubled) of the interaction were considered. Red alder grew relatively better at Cascade Head Experimental Forest in the Coast Range, while Douglas-fir grew better at H.J. Andrews Experimental Forest in the less temperate Cascade Mountains. Possible production benefits from mixed plantings were examined using two methods of calculation. Potential production benefits from certain planted proportions of the two species occurred at H.J. Andrews Experimental Forest. No planting time or species proportion resulted in yield improvements over monoculture stands at Cascade Head Experimental Forest. Understory species also varied because of differences in site and stand characteristics that resulted from the differences in planting times and species proportions.

scholarly journals The economics of converting red alder to Douglas-fir /

1969 ◽  
Author(s):  
James Gibson Yoho ◽  
Daniel E. Chappelle ◽  
Dennis L. Schweitzer
Keyword(s):  
Douglas Fir ◽  
Red Alder
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