Development over 25 years of Douglas-fir, western hemlock, and western redcedar planted at various spacings on a very good site in British Columbia.

Donald L. Reukema; J. Harry G. Smith

doi:10.2737/PNW-RP-381

Treesearch

Development over 25 years of Douglas-fir, western hemlock, and western redcedar planted at various spacings on a very good site in British Columbia.

Informally Refereed

Authors:

Donald L. Reukema, J. Harry G. Smith

Year:

1987

Type:

Research Paper

Station:

Pacific Northwest Research Station

DOI:

https://doi.org/10.2737/PNW-RP-381

Source:

Res. Pap. PNW-RP-381. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. 46 p

Download (PDF 2.49 MB)

Download (PDF 2.49 MB): https://research.fs.usda.gov/download/treesearch/9217.pdf

Abstract

Results of five spacing trials on the University of British Columbia Research Forest, covering a range of plantation spacings from 1 to 5 meters, showed that choice of initial spacing is among the most important factors influencing bole and crown development and stand growth and yield. The trials include Douglas-fir (Pseudotsuga menziesi), western hemlock (Tsuga heterophylla), and western redcedar (Thuja plicata). The results to date should help managers to choose optimum spacings for their purposes. Initial wide spacings with rectangularities up to 2:1, such as 6 by 3 meters, resulted in efficient production of large trees of high value and satisfactory quality. Pruning of widely spaced trees to enhance quality of the lower bole is strongly recommended.

Keywords

Plantation spacing, growth, stand development, density, height increment, diameter increment, crown development

Citation

Reukema, Donald L.; Smith, J. Harry G. 1987. Development over 25 years of Douglas-fir, western hemlock, and western redcedar planted at various spacings on a very good site in British Columbia. Res. Pap. PNW-RP-381. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. 46 p