Manual release in an "old" Douglas-fir plantation increases diameter growth

Philip M. McDonald; Gary Fiddler; Richard Tucker; Andrew Colaninno

doi:10.2737/PSW-RN-405

Treesearch

Manual release in an "old" Douglas-fir plantation increases diameter growth

Informally Refereed

Authors:

Philip M. McDonald, Gary Fiddler, Richard Tucker, Andrew Colaninno

Year:

1989

Type:

Research Note

Station:

Pacific Southwest Research Station

DOI:

https://doi.org/10.2737/PSW-RN-405

Source:

Res. Note PSW-RN-405. Berkeley, CA: U.S. Department of Agriculture, Forest Service, Pacific Southwest Forest and Range Experiment Station. 3 p

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Download (PDF 359 KB): https://research.fs.usda.gov/download/treesearch/30706.pdf

Abstract

Twelve-year-old Douglas-fir saplings on the Mad River Ranger District, Six Rivers National Forest, California were released by cutting competing vegetation in a 9-foot radius to test the timing and efficacy of this method in plantations older than those in which such work traditionally is doneÂ—the first 5 years. Nine years after release, the average stem diameter (3.60 inches or 9.14 cm) of released Douglas-fir saplings, taken at 12 inches (30 cm) above mean groundline, differed significantly from that of control saplings (2.98 inches or 7.57 cm) (p0.05). In spite of this finding, the stem diameter of released saplings was 40 percent less than that needed to comply with regional Forest Service growth objectives. Cost of release averaged $428 per acre or $1058/ha in 1978 dollars.

Keywords

manual release, cost, growth, Douglas-fir, northern California

Citation

McDonald, Philip M.; Fiddler, Gary O.; Tucker, Richard A.; Colaninno, Andrew. 1989. Manual release in an "old" Douglas-fir plantation increases diameter growth. Res. Note PSW-RN-405. Berkeley, CA: U.S. Department of Agriculture, Forest Service, Pacific Southwest Forest and Range Experiment Station. 3 p.