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

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

not available

scholarly journals Comparison of Root System Morphology of Cucurbit Rootstocks for Use in Watermelon Grafting

2018 ◽  
Vol 28 (5) ◽  
pp. 629-636 ◽  
Author(s):  
Matthew B. Bertucci ◽  
David H. Suchoff ◽  
Katherine M. Jennings ◽  
David W. Monks ◽  
Christopher C. Gunter ◽  
...  
Keyword(s):  
Root System ◽  
Surface Area ◽  
Root Length ◽  
Dry Weight ◽  
Root Systems ◽  
Root Surface ◽  
Root Diameter ◽  
Root Surface Area ◽  
Diameter Class ◽  
Main Effect

Grafting of watermelon (Citrullus lanatus) is an established production practice that provides resistance to soilborne diseases or tolerance to abiotic stresses. Watermelon may be grafted on several cucurbit species (interspecific grafting); however, little research exists to describe root systems of these diverse rootstocks. A greenhouse study was conducted to compare root system morphology of nine commercially available cucurbit rootstocks, representing four species: pumpkin (Cucurbita maxima), squash (Cucurbita pepo), bottle gourd (Lagenaria siceraria), and an interspecific hybrid squash (C. maxima × C. moschata). Rootstocks were grafted with a triploid watermelon scion (‘Exclamation’), and root systems were compared with nongrafted (NG) and self-grafted (SG) ‘Exclamation’. Plants were harvested destructively at 1, 2, and 3 weeks after transplant (WAT), and data were collected on scion dry weight, total root length (TRL), average root diameter, root surface area, root:shoot dry-weight ratio, root diameter class proportions, and specific root length. For all response variables, the main effect of rootstock and rootstock species was significant (P < 0.05). The main effect of harvest was significant (P < 0.05) for all response variables, with the exception of TRL proportion in diameter class 2. ‘Ferro’ rootstock produced the largest TRL and root surface area, with observed values 122% and 120% greater than the smallest root system (‘Exclamation’ SG), respectively. Among rootstock species, pumpkin produced the largest TRL and root surface area, with observed values 100% and 82% greater than those of watermelon, respectively. These results demonstrate that substantial differences exist during the initial 3 WAT in root system morphology of rootstocks and rootstock species available for watermelon grafting and that morphologic differences of root systems can be characterized using image analysis.

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.

Root system variability in common legumes in Central Europe

Biologia ◽  
2012 ◽  
Vol 67 (1) ◽  
Author(s):  
Lucie Chmelíková ◽  
Michal Hejcman
Keyword(s):  
Root System ◽  
Root Systems ◽  
Life Forms ◽  
Root Diameter ◽  
Legume Species ◽  
Minimum Diameter ◽  
Lupinus Polyphyllus ◽  
Nodule Shape ◽  
System Variability ◽  
Trifolium Arvense

AbstractThe aim of this study was to provide an overview of field measured root systems of common legume species growing under different environmental conditions in the Czech Republic. The plants, 214 individuals of 21 selected legume species from the tribes Galegeae (Astragalus glycyphyllos, Lupinus polyphyllus), Genisteae (Cytisus scoparius, Genista tinctoria), Loteae (Anthyllis vulneraria, Lotus corniculatus, Securigera varia), Trifolieae (Trifolium arvense, T. campestre, T. medium, T. pratense, T. repens) and Vicieae (Lathyrus pratensis, L. sylvestris, Vicia angustifolia, V. cracca, V. hirsuta), were collected using the monolith method from 27 sites.A rhizome was present in seven species and the maximum branching order was three for 15 species and five for five species. Recovery buds were recorded on the root system of eight species and woodiness was recorded in 11 species. Root diameter ranged from 1 to 12 mm — the minimum diameter was recorded in annuals and the maximum in perennials. The colour of the root system ranged from light to dark. In six species, young roots were light and older roots were dark. Globose, cylindrical, branched, fan-like and ruff-like nodules were recorded. Only one type of nodule shape was recorded in 11 species, two in seven species and three or four in three species. Nodules measured up to 2 mm in nine species, from 2 to 4 mm in three species and more than 4 mm in nine species. Legume root systems are highly variable and the variability was due to Raunkier’s life forms rather than membership of a tribe.

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.

scholarly journals Controls on creek margin stability by the root systems of saltmarsh vegetation, Beaulieu Estuary, Southern England

2019 ◽  
Vol 2 (1) ◽  
pp. 21-38 ◽  
Author(s):  
Yining Chen ◽  
Charlotte Thompson ◽  
Michael Collins
Keyword(s):  
High Resistance ◽  
Three Dimensional ◽  
Ct Scanning ◽  
Root Systems ◽  
Distribution Patterns ◽  
Root Diameter ◽  
Diameter Distribution ◽  
Southern England ◽  
Quantitative Measurements ◽  
Atriplex Portulacoides

The retreat of cliffs (lateral expansion) within tidal creeks results in a net loss of saltmarshes, but this retreat process can be retarded by root systems. To understand the interaction between root presence and bank sediment, quantitative measurements of two saltmarsh species root systems (Atriplex portulacoides and Juncus maritima) were carried out in a saltmarsh in Southern England, and their relationships with bank stability were examined. Computed Tomography (CT) Scanning techniques were used to investigate three-dimensional root architecture. The data obtained (e.g., root volume, diameter, and distribution patterns of roots) were examined alongside more traditional root density measurements. The volumetric percentage, ratio between horizontal (lateral) and vertical roots (H/V ratio), and root diameter distribution are discussed in relation to their influence on bank sediment erosion threshold and shear strength. The results suggest that Atriplex portulacoides is more effective than Juncus maritimus in stabilising banks. This is because root systems that provide a high resistance to flow-induced erosion are better than those that provide a high resistance to gravity-induced erosion in stabilising cliff banks. This conclusion is relevant to future saltmarsh protection and re-establishment.

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.

Reduction of Phellinusweirii inoculum in Douglas-fir stumps by the fumigant Telone ll-B

1995 ◽  
Vol 25 (1) ◽  
pp. 63-68 ◽  
Author(s):  
R.G. Fraser ◽  
J.D. Beale ◽  
R.J. Nevill
Keyword(s):  
Root Biomass ◽  
Control Measure ◽  
Large Diameter ◽  
Root Diameter ◽  
Douglas Fir ◽  
Soil Samples ◽  
Effective Control ◽  
Residual P ◽  
Diameter Classes

Two dosages of Teione II-B (1,3-dichloropropene) at 3.4 and 6.7 mL/kg of stump and root biomass were tested to determine the efficacy in reducing Phellinusweirii (Murr.) Gilb. inoculum in infected Douglas-fir, Pseudotsugamenziesii (Mirb.) Franco, stumps. After 21 months, both doses of Teione II-B proved equally effective and significantly (p < 0.05) reduced residual P. weirii mycelium in infected roots. Fumigation reduced residual endotrophic P. weirii in the large-diameter root classes nearest the stump, but survival of the fungus was less affected with increasing distance from the stump and in the smaller root diameter classes. Treated stumps also had significantly (p < 0.05) fewer roots with ectotrophic mycelium than untreated stumps. Four weeks after application, soil samples taken near treated stumps revealed no evidence of the fumigant. These findings suggest that application of Teione II-B could be used as an effective control measure for P. weirii.

Architecture of the skeletal root system of 40-year-old Picea abies on strongly acidified soils in the Harz Mountains (Germany)

1998 ◽  
Vol 28 (1) ◽  
pp. 13-22 ◽  
Author(s):  
Michael Drexhage ◽  
Franz Gruber
Keyword(s):  
Picea Abies ◽  
Root System ◽  
Forest Decline ◽  
Stand Density ◽  
Root Systems ◽  
Root System Architecture ◽  
Root Diameter ◽  
Functional Difference ◽  
Cross Sectional ◽  
Woody Root

Altogether 15 root systems, five at each of three plots (north- and south-facing slopes and plateau), of 40-year-old Picea abies (L.) Karst. trees with different symptoms of forest decline were excavated down to a root diameter of 0.5 cm. The object was to investigate the variability of root morphology and to assess the influence of environmental variation on the architecture of the woody root system. For each tree, total height, diameter at breast height, and needle and twig biomasses were determined, and for each root system, biomass, growth, length, cross-sectional area, number and initial direction of branches, and branching forms were determined. The differences in many of the wood parameters within and between the plots were relatively few, so that forest decline symptoms determined at the crown could not be sufficiently related to the root system architecture. The results suggest a small influence of microsite conditions on the structural root systems, an influence of stand density on root distribution and soil exploitation, and a functional difference between horizontal and vertical roots that points out the importance of extensive long vertical roots, which insure a sufficient water and nutrient uptake.

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