Relation of initial spacing and relative stand density indices to stand characteristics in a Douglas-fir plantation spacing trial

Robert O. Curtis; Sheel Bansal; Constance A. Harrington

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USGS · 70173842

Relation of initial spacing and relative stand density indices to stand characteristics in a Douglas-fir plantation spacing trial

Robert O. Curtis·Sheel Bansal·Constance A. Harrington

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Abstract

This report presents updated information on a 1981 Douglas-fir ( Pseudotsuga menziesii (Mirb.) Franco var. menziesii ) plantation spacing trial at 33 years from planting. Stand statistics at the most recent measurement were compared for initial spacing of 1 through 6 meters and associated relative densities. There was no clear relationship of spacing to top height. Diameter, live crown ratio, and percent survival increased with spacing; basal area and relative density decreased with increase in spacing. Volume in trees ≥ 4 cm diameter was greatest at 2 m spacing, while utilizable volume (trees ≥20 cm dbh) was greatest at 4 m spacing. Live crown ratio decreased and total crown projectional area increased with increasing relative density indices. Total crown projectional area was more closely related to relative density than to basal area.

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Source-reported bounding extent: 45.778299066443104° to 45.86730177869196° latitude; -122.0797348022461° to -121.92420959472655° longitude. This indicates report coverage, not an exact sampling location. View area on OpenStreetMap.

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Robert O. Curtis, Sheel Bansal, Constance A. Harrington. 2016. Relation of initial spacing and relative stand density indices to stand characteristics in a Douglas-fir plantation spacing trial. https://pubs.usgs.gov/publication/70173842

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