Root systems of older immature hemlock, cedar, and Douglas-fir

1988 ◽  
Vol 18 (5) ◽  
pp. 657-657
Author(s):  
S. Eis
Keyword(s):  
Root Systems ◽  
Douglas Fir

not available

Twenty-year survival of Phellinus (Poria) weirii in Douglas-fir stumps

1976 ◽  
Vol 6 (2) ◽  
pp. 123-128 ◽  
Author(s):  
Everett M. Hansen
Keyword(s):  
Root Systems ◽  
Root Diameter ◽  
Douglas Fir ◽  
Hand Tools ◽  
Outer Limit ◽  
Dying Back

Fungus survival was examined in root systems of stumps of trees that were harvested 20 years previously. Roots were excavated with dynamite and hand tools to the outer limit of living P. weirii or until the roots went deeper than 45 cm. Sixty-nine stumps infected before harvest were excavated; P. weirii was still viable in 94%. The fungus was dying back in 68% of the stumps. Some roots as small as 1.3 cm had viable P. weirii, but the margin between living and dead P. weirii occurred at an average root diameter of 12.5 cm.The margin between living and dead P. weirii was often marked by a black zone line. The fungus survived only within roots with intact bark. Ectotrophic mycelium occurred in discontinuous patches on roots of 33% of the stumps.

Root systems of older immature hemlock, cedar, and Douglas-fir

1987 ◽  
Vol 17 (11) ◽  
pp. 1348-1354 ◽  
Author(s):  
S. Eis
Keyword(s):  
Root Systems ◽  
Douglas Fir ◽  
Western Hemlock ◽  
Organic Horizon ◽  
Red Cedar ◽  
Western Red Cedar ◽  
Absorbing Roots

Root systems of eight western hemlock (Tsugaheterophylla (Raf.) Sarg.), eight western red cedar (Thujaplicata Donn.), and six Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) trees, average age about 50 years, average dbh 26.3 cm, were hydraulically excavated. The sizes and shapes of the root systems are given and the root systems and roots are described. Fresh and dry weights of roots of all vegetation averaged 36 and 14 t/ha and were similar for all three species. Fine absorbing roots were distributed mainly in the organic horizon and immediately below it, i.e., in the top 10 or 15 cm of the soil; their turnover appears rapid. Their ovendry weight averaged 210 g/m2 and their length averaged 4 km/m2.

A rapid method for detecting cold injury in conifer seedling root systems

1990 ◽  
Vol 20 (1) ◽  
pp. 26-30 ◽  
Author(s):  
Gary A. Ritchie
Keyword(s):  
Weight Loss ◽  
Root Systems ◽  
Douglas Fir ◽  
Cold Injury ◽  
Percent Weight Loss ◽  
Seedling Root ◽  
Seedling Roots ◽  
Temperature Exposure ◽  
Low Temperature Exposure ◽  
Conifer Seedling

A method is described for rapidly determining the extent of cold injury to Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) seedling root systems. It is based upon pressure:volume theory but short-cuts the tedious pressure:volume method. Injured root systems were brought to full hydration, then weighed and placed into a pressure chamber. A pressure of 1.5 MPa was applied for a 5-min period, then the root system was removed from the chamber and reweighed. The percent weight loss was then calculated. Percent weight loss was closely related to degree of low temperature exposure in Douglas-fir seedling roots. Percent weight loss values were near 5 in uninjured controls, whereas freeze-injured seedlings had percent weight loss values of 7 or greater. Percent weight loss values measured on seedlings just before planting were closely correlated with seedling vigor and mortality 3 months following planting in both a field test and a greenhouse pot trial.

Comparative root system morphologies of seeded-in-place, bareroot, and containerized Douglas-fir seedlings after outplanting

1979 ◽  
Vol 9 (3) ◽  
pp. 399-405 ◽  
Author(s):  
C. L. Preisig ◽  
W. C. Carlson ◽  
L. C. Promnitz
Keyword(s):  
Root System ◽  
Lateral Root ◽  
Root Systems ◽  
Douglas Fir ◽  
Tree Stability ◽  
Stock Type ◽  
Stock Types ◽  
Root Orientation

Root systems of 5- to 8-year-old Pseudotsugamenziesii (Mirb.) Franco seedlings of natural, bareroot, and container origin were quantitatively analyzed to determine the effects of seedling source on root system morphology. Lateral root orientation was stressed.Container and planting constrictions on root system morphology were recognizable after outplanting; planted stock types were differentiated from seeded-in-place seedlings on the basis of root system morphology. Container and natural seedlings had less variation in root system morphology within stock type than bareroot stock. Root spiraling was so low in the Douglas-fir stock types studies that it is not likely to affect tree stability. There was no overall effect of root system morphology on height of seedlings around 6 years of age.

CHARACTERISTICS OF DOUGLAS-FIR ROOT SYSTEMS

1963 ◽  
Vol 41 (1) ◽  
pp. 105-122 ◽  
Author(s):  
R. G. McMinn
Keyword(s):  
Pseudotsuga Menziesii ◽  
Root Systems ◽  
Douglas Fir ◽  
Forest Pathology ◽  
Rooting Density

The root systems of 28 Douglas fir (Pseudotsuga menziesii (Mirb.) Franco) in four stands, aged 10, 25, 40, and 55 years, were excavated hydraulically to determine the rooting characteristics of trees in different crown classes at various ages. The extent, depth, configuration, rooting density, and mycorrhizal component of root systems were examined. The significance of the characteristics observed is discussed in relation to silviculture, nursery practice, and forest pathology.

Lateral Root Pruning – A Promising Forest Nursery Practice

1968 ◽  
Vol 44 (5) ◽  
pp. 12-13 ◽  
Author(s):  
S. Eis
Keyword(s):  
Lateral Root ◽  
Root Systems ◽  
Douglas Fir ◽  
Root Pruning ◽  
Height Increment ◽  
Forest Nursery

The regeneration and growth of pruned roots of Douglas-fir seedlings were studied under nursery conditions. Root pruning did not decrease the height increment of seedlings. For the best development of dense and compact root systems, the bottom pruning should be done early in spring and the side pruning around the middle of June, on both sides of the row simultaneously.

Transport of Nutrients to Tree Root Systems

1974 ◽  
Vol 4 (4) ◽  
pp. 563-565 ◽  
Author(s):  
T. M. Ballard ◽  
D. W. Cole
Keyword(s):  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Mass Flow ◽  
Nutrient Transport ◽  
Root Systems ◽  
Douglas Fir ◽  
Nitrogen Transport ◽  
Ca Uptake ◽  
Glacial Outwash

Calculations suggest that nutrient transport through the soil to roots by mass flow accounts for less than 22, 37, and 80%, respectively, of the N, K, and Ca uptake by a Douglas-fir stand growing on a nitrogen-deficient soil derived from glacial outwash. Diffusion and dispersion, though limited by soil water content, are evidently especially important in nitrogen transport to root systems in this soil.

Root System Morphology of Western Hemlock, Western Red Cedar, and Douglas-fir

1974 ◽  
Vol 4 (1) ◽  
pp. 28-38 ◽  
Author(s):  
S. Eis
Keyword(s):  
Soil Depth ◽  
Root Systems ◽  
Douglas Fir ◽  
Western Hemlock ◽  
Root Penetration ◽  
Root Weight ◽  
Lake Area ◽  
Red Cedar ◽  
Western Red Cedar ◽  
Absorbing Roots

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.

Root system response of naturally regenerated Douglas-fir (Pseudotsuga menziesii) after complete overstory removal

2012 ◽  
Vol 42 (10) ◽  
pp. 1858-1864 ◽  
Author(s):  
Nathan A. Briggs ◽  
Christian Kuehne ◽  
Ulrich Kohnle ◽  
Jürgen Bauhus
Keyword(s):  
Pseudotsuga Menziesii ◽  
Root Elongation ◽  
Small Sample Size ◽  
Root Systems ◽  
Douglas Fir ◽  
Small Sample ◽  
System Response ◽  
Radial Increment ◽  
Advance Regeneration ◽  
Closed Canopy

Long regeneration periods, which result in two-layered or multilayered forest stands, are an important element of the close-to-nature forest management paradigm in central Europe. Such extended regeneration periods, however, may lead to undesirable development of advance regeneration, specifically in species such as Douglas-fir ( Pseudotsuga menziesii (Mirb.) Franco) where root growth is strongly curtailed under competition. We hypothesized that root systems of naturally regenerated Douglas-fir that had grown under closed canopy for prolonged periods would be inhibited in their capacity to develop adequate structural root systems following release through removal of the canopy. Complete root systems of six approximately 25-year-old Douglas-fir that had grown for at least 12 years underneath a closed canopy before overstory removal were excavated using subterranean explosives. Root elongation, radial increment of primary lateral and vertical roots, and aboveground stem growth were investigated using retrospective analysis of growth rings. Structural roots of the previously suppressed Douglas-fir were capable of strongly responding to release from competition relative to growth prior to removal, but this response, particularly in the form of root elongation, was delayed. However, since the growth response of roots was not stronger than that above ground, an imbalanced root to shoot ratio, likely developed in trees when grown under the canopy, was not reverted. Generalizing interpretation of the derived findings of this study is limited because of the small sample size and the lack of freely grown control trees. Whether or not previously suppressed trees can develop the same physical stability as open-grown individuals therefore deserves further investigation.

Predicting root biomass from branching patterns of Douglas-fir root systems

Oikos ◽  
2003 ◽  
Vol 100 (1) ◽  
pp. 96-104 ◽  
Author(s):  
Andrew D. Richardson ◽  
Heinrich Zu Dohna
Keyword(s):  
Root Biomass ◽  
Root Systems ◽  
Douglas Fir ◽  
Branching Patterns
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