Development of top heights and corresponding diameters in high-elevation noble fir plantations

Robert Curtis

doi:10.2737/PNW-RP-603

Treesearch

Development of top heights and corresponding diameters in high-elevation noble fir plantations

Informally Refereed

Authors:

Robert Curtis

Year:

2015

Type:

Research Paper

Station:

Pacific Northwest Research Station

DOI:

https://doi.org/10.2737/PNW-RP-603

Source:

Res. Pap. PNW-RP-603. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. 20 p.

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Abstract

Height and diameter growth of noble fir (Abies procera Rehd.) trees included in the largest 40 stems per acre were compared in a study that included five precommercial thinning spacings plus no thinning, in each of eight replications, at elevations from 2,200 to 4,100 feet in the western Cascade Mountains of Washington and Oregon. Height growth rates were not affected by spacing. The unthinned treatment had slightly greater initial heights, a difference that probably arose from the method used to select leave trees in thinning. Height trends differed markedly from those given in Herman et al. (1978); which should not be used in plantations. Spacing had a considerable though highly variable effect on diameter growth of these dominant trees. New top height/age curves are presented, which can be used for interim site classification pending availability of data that includes a greater range of ages.

Keywords

Nobile fir, plantations, thinning

Citation

Curtis, Robert O. 2015. Development of top heights and corresponding diameters in high-elevation noble fir plantations. Res. Pap. PNW-RP-603. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. 20 p.