Canadian Forest Service Publications

Root system morphology of western hemlock, western red cedar and Douglas-fir. 1974. Eis, S. Canadian Journal of Forest Research 4(1): 28-38.

Year: 1974

Issued by: Pacific Forestry Centre

Catalog ID: 1562

Language: English

Availability: Not available through the CFS (click for more information).

Available from the Journal's Web site.
DOI: 10.1139/x74-005

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Root systems of nine western hemlock (Tsugaheterophylla (Raf.) Sarg.), nine western red cedar, (Thujaplicata (Donn), and six Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) trees were hydraulically excavated in the Cowichan Lake area on Vancouver Island. All three species were similar in depth of root penetration, presence of oblique laterals and sinkers, concentration of rope-like, higher-order laterals, and fine absorbing roots below the organic–mineral interphase, on top of the hardpan and in pockets of organic or fine mineral material. Dominants had proportionally larger and more symmetrical root systems than trees of lower canopies; asymmetry generally increased with increasing stoniness and decreasing soil depth. All three species showed a somewhat greater root development on the downhill side, but exceptions were frequent. Douglas-fir had a larger root spread, roots of larger diameters and smaller taper, and proportionally greater root weight than cedar or hemlock. The density of thin, rope-like roots and absorbing roots was highest on cedar and lowest on Douglas-fir. Hemlock roots followed old decaying roots more frequently than cedar or fir, but root channels were equally used by all species.