Internal fungi in old-growth Douglas fir foliage

1977 ◽  
Vol 55 (6) ◽  
pp. 644-653 ◽  
Author(s):  
Mary E. Bernstein ◽  
George C. Carroll
Keyword(s):  
Transverse Section ◽  
Fungal Infections ◽  
Douglas Fir ◽  
Tree Canopy ◽  
Western Slope ◽  
Scanning Electron Micrographs ◽  
Old Growth ◽  
The Individual ◽  
Individual Trees ◽  
Oregon Cascades

Culture of surface-sterilized needles from a stand of old-growth Douglas fir trees on the western slope of the Oregon Cascades revealed the presence of latent fungal infections in all needles examined older than 3 years. Scanning electron micrographs of cut needle surfaces seen in transverse section showed occasional intercellular fungal hyphae in the needle parenchyma. Two species of fungi, Phyllosticta sp. and a suspected member of the Hemiphacidiaceae, appeared as the major colonizers of the needle blade; a third species, as yet unidentified, commonly grew out from the needle petiole. Endophytes were widespread in needles throughout the watershed regardless of the elevation and exposure of the individual trees sampled. Similarly, height of the needles in the tree canopy showed little correlation with the frequency of internal infections. Individual needles were cut into 10 segments before culture, and patterns of endophyte distribution within the needles were observed. The data are consistent with the hypothesis that needles are multiply infected during their 1st year. The initial rise in endophyte frequency occurs between November and March on 1st-year needles, a pattern suggesting waterborne spores as agents of infection. Both Phyllosticta and the hemiphacidiaceous fungus are known to produce gloeoid conidia, which are thought to be dispersed by rain. With increasing age, all needle segments become infected with endophytes.

YELLOW LAMINATED ROOT ROT OF DOUGLAS FIR

1954 ◽  
Vol 32 (1) ◽  
pp. 69-81 ◽  
Author(s):  
D. C. Buckland ◽  
A. C. Molnar ◽  
G. W. Wallis
Keyword(s):  
Root Rot ◽  
Douglas Fir ◽  
Common Occurrence ◽  
Individual Host ◽  
Second Growth ◽  
Bark Tissue ◽  
Causal Fungus ◽  
The Common ◽  
The Individual ◽  
Individual Trees

Yellow laminated root rot occurs in most native conifers throughout the range of Douglas fir in British Columbia. The cause of this disease has been ascribed to a variety of Poria weirii Murr., or a species of Poria distinct from P. weirii. The fungus grows from infected to healthy roots through physiologically weakened contacting points or fusions, and the disease is most prevalent in Douglas fir because of the common occurrence of root fusion in this species. Douglas fir is susceptible at any age over six years but individual trees show marked differences in their resistance to killing by the disease. The symptom picture varies greatly between infected trees and is directly related to the resistance shown by the individual host. Inoculum may remain viable for over 50 years in stumps and roots. The fungus does not appear to spread through the soil nor does it appear to be able to penetrate healthy bark tissue. Although the control of this disease is currently important in many localized areas, several characteristics in the behavior of the causal fungus indicate that it will become more important as management of second growth Douglas fir forests becomes more intensive.

The effect of soil disturbance on growth and ectomycorrhizae of Douglas-fir and western hemlock seedlings: a greenhouse bioassay

1982 ◽  
Vol 12 (2) ◽  
pp. 343-353 ◽  
Author(s):  
M. Meyer Schoenberger ◽  
D. A. Perry
Keyword(s):  
Soil Disturbance ◽  
Douglas Fir ◽  
Western Hemlock ◽  
Root Tips ◽  
Old Growth ◽  
Clear Cut ◽  
Old Growth Forest ◽  
Litter Leachate ◽  
Oregon Cascades ◽  
Tip Formation

In a greenhouse bioassay of soils from the central Oregon Cascades, Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) seedlings had the most total and ectomycorrhizal root tips when grown in soil from an unburned clear-cut and the least when grown in soil from (i) a 20-year-old plantation that had been clear-cut and burned in the late 1950's and (ii) one old-growth forest. Tip formation was intermediate in soil from a second old-growth forest, a recently burned clear-cut, and a 40-year-old natural burn. Root weights followed the same trend, but top weights did not differ among the various soils. Ectomycorrhizal and total root tips of western hemlock (Tsugaheterophylla (Raf.) Sarg.) were lowest in soils from the plantation and recently burned clear-cut. Unlike Douglas-fir, western hemlock's tip production was not greater in the unburned clear-cut than in the old-growth forest soils. In this species, both top and root weights varied according to soil, with the largest seedlings produced in soil from the unburned clear-cut. With both species, there was a significant interaction between ectomycorrhizal type and soil type. Cenococcumgeophilum Fr. predominated on western hemlock and was reduced in soils from the burned clear-cut and plantation. In comparison with the mean for all soils, ectomycorrhizal types that predominated on Douglas-fir were enhanced in the unburned clear-cut soil and reduced in one old-growth soil, an effect apparently related to litter leachate.

Quantifying the vertical diversification development stage of old-growth Douglas-fir to derive stage-specific targets for restoration silviculture

2021 ◽  
pp. 1-9
Author(s):  
Eric K. Zenner ◽  
JeriLynn E. Peck
Keyword(s):  
Development Stage ◽  
Douglas Fir ◽  
Diameter Distribution ◽  
Developmental Sequence ◽  
Old Growth ◽  
New Approach ◽  
Single Tree ◽  
Simple Index ◽  
Single Tree Selection ◽  
Oregon Cascades

Structural variability in natural Douglas-fir (Pseudotsuga menziesii (Mirbel) Franco) forests hinders restoration targets for the full old-growth developmental sequence. To guide stage-specific restoration, we present a new approach toward developing a simple index of the vertical diversification (VD) stage. VD-associated sub-stand structures were objectively identified by quantifying the size structures of live trees across a developmental sequence of 10 pristine stands in the Oregon Cascades, USA. Floating neighborhoods were used to delineate natural tree neighborhoods based on triangulated irregular networks in five concentric rings of ever-greater spatial extent (averaging 60–2060 m2). Diameter distributions summarized the most frequently encountered tree size structures among neighborhoods, with increasing deviation from the neutral multi-variate core. Of 18 observed diameter distribution types (DDTs), the core DDT characterized all-sized tree neighborhoods reflective of vertical diversification, which was most abundant in early old-growth (VD) stands and least abundant at the extremes of the sequence. VD declined in older stands, whose more distinct DDTs had peaks in larger trees and multiple size classes, likely reflecting horizontal diversification (HD). This new approach illustrates that structural restoration of VD stands could be facilitated by the single-tree selection method, while that of HD stands may be promoted with both single-tree and group selection as well as targeted release.

Is it Worth CANVASing for CREDENCE? A Benefit-risk Analysis

2020 ◽  
Vol 16 (5) ◽  
pp. 509-514
Author(s):  
Binayak Sinha ◽  
Samit Ghosal
Keyword(s):  
Adverse Events ◽  
Fungal Infections ◽  
Absolute Risk ◽  
Pooled Analysis ◽  
Major Adverse Cardiovascular Events ◽  
Number Needed To Treat ◽  
Pooled Data ◽  
The Individual ◽  
Fracture Risks ◽  
Number Needed To Harm

Background and Aims: A number of significant positive and negative signals emerged from the CANVAS Program and CREDENCE trial with the use of canagliflozin. These signals are confusing. A Likelihood of being Helped of Harmed (LHH) analysis was conducted to determine the risk, benefit ratio associated with canagliflozin use and address the signals as a continuum. Materials &Methods: LHH was calculated from the number needed to treat (NNT) and number needed to harm (NNH) available from the absolute risk reductions reported with the outcomes of interest, in these two trials. Results: In the CANVAS Program, LHH for major adverse cardiovascular events (MACE) points at a significant benefit with canagliflozin use in comparison to amputation (1.65), fractures (1.65) and euglycaemic diabetic ketoacidosis (euDKA) (16.67) risks. Only genital fungal infections were significant more in both sexes (0.21-M and 0.1-F) when LHH was matched against the positive outcomes. In contrast, the hHF benefits were outweighed by amputation (0.95) and fracture risks (0.95). : In CREDENCE trial, the LHH for Primary composite, Renal composite and MACE, all supported the benefits in comparison to any adverse events encountered in the trial. : The LHH from pooled data (CANVAS Program and CREDENCE trial) was in favour of all the benefits (hHF and renal composites) except for MACE matched against amputation (0.66). Conclusion: The outcome benefits were in favour of canagliflozin in comparison to all reported adverse events, when hHF and renal composite were under consideration, in both the individual and pooled LHH analysis. However, the MACE benefits were overwhelmed by amputation risk in the pooled analysis.

Comparison of Methods of Estimating Leaf-Area Index In Old-Growth Douglas-Fir

Ecology ◽  
1986 ◽  
Vol 67 (4) ◽  
pp. 975-979 ◽  
Author(s):  
J. D. Marshall ◽  
R. H. Waring
Keyword(s):  
Leaf Area Index ◽  
Leaf Area ◽  
Douglas Fir ◽  
Comparison Of Methods ◽  
Old Growth ◽  
Area Index

Assyrian sacred trees in the Brooklyn Museum

Iraq ◽  
1994 ◽  
Vol 56 ◽  
pp. 123-133 ◽  
Author(s):  
Pauline Albenda
Keyword(s):  
Present Author ◽  
Ninth Century ◽  
Palm Tree ◽  
The West ◽  
Individual Tree ◽  
Sacred Tree ◽  
The Individual ◽  
Individual Trees ◽  
Brooklyn Museum ◽  
Tree Type

The Brooklyn Museum houses twelve stone slabs with carved decoration from the Northwest Palace of Ashurnasirpal II. The motif of a stylized tree — the so-called Sacred Tree (see Figs. 1, 4, 6) — appears on seven of those slabs which come from rooms F, I, L, S, T of the ninth century palace at Nimrud. These tree renderings are representative of the sacred tree-type found in ten rooms of the royal residence and the west wing. Approximately 96 sacred trees, in two-register arrangement, appeared on the pictorial decorations in room I; the same motif occurred about 75 times in one-register arrangement on the reliefs of the other rooms. The abundance of the sacred tree motif on the wall decorations of the Northwest Palace attests to the significance of this plant. Its design deserves investigation; in Layard's words, “the tree, evidently a sacred symbol, is elaborately and tastefully formed.”In his study of the Ashurnasirpal II reliefs in American collections, Stearns did not attempt to list the sacred trees, because “variations in the sacred tree occur only in minor details,” and “the tree in itself is rarely useful in identifying the location of the reliefs.” These statements make clear Stearns' belief that the sacred trees were nearly alike. Other scholars, notably Weidner and Reade, have pointed out that on a number of slabs now in American and European museums are carvings of matching half trees, therefore indicating that when paired, these trees belonged to adjoining slabs originally. In trying to match half trees, one finds that individual sacred trees do differ in the rendering of specific details. Bleibtreu, in her analysis of the sacred tree-type, lists three variants of the flower found on the palmette-garland framing the individual tree on three sides. The present author, after examining the sacred trees carved on the slabs in The Brooklyn Museum, concludes that the design of the tree-type is more varied than heretofore presumed, and that its construction is more complex than indicated in previous descriptions of the subjects. An analysis of the Assyrian sacred tree-type may lead to possible conclusions regarding its intended image: a stylized palm tree, a cult object, an emblem of vegetation or “tree of life”, an imperial symbol, or a combination of those forms. In addition, one may consider to what extent the rendering of individual trees was the consequence of artistic inventiveness.

scholarly journals Automatic Extraction of Grasses and Individual Trees in Urban Areas Based on Airborne Hyperspectral and LiDAR Data

2020 ◽  
Vol 12 (17) ◽  
pp. 2725
Author(s):  
Qixia Man ◽  
Pinliang Dong ◽  
Xinming Yang ◽  
Quanyuan Wu ◽  
Rongqing Han
Keyword(s):  
Urban Areas ◽  
Three Dimensional ◽  
Hyperspectral Data ◽  
Classification Method ◽  
Urban Vegetation ◽  
Individual Tree ◽  
Cloud Data ◽  
Random Forest Classification ◽  
The Individual ◽  
Individual Trees

Urban vegetation extraction is very important for urban biodiversity assessment and protection. However, due to the diversity of vegetation types and vertical structure, it is still challenging to extract vertical information of urban vegetation accurately with single remotely sensed data. Airborne light detection and ranging (LiDAR) can provide elevation information with high-precision, whereas hyperspectral data can provide abundant spectral information on ground objects. The complementary advantages of LiDAR and hyperspectral data could extract urban vegetation much more accurately. Therefore, a three-dimensional (3D) vegetation extraction workflow is proposed to extract urban grasses and trees at individual tree level in urban areas using airborne LiDAR and hyperspectral data. The specific steps are as follows: (1) airborne hyperspectral and LiDAR data were processed to extract spectral and elevation parameters, (2) random forest classification method and object-based classification method were used to extract the two-dimensional distribution map of urban vegetation, (3) individual tree segmentation was conducted on a canopy height model (CHM) and point cloud data separately to obtain three-dimensional characteristics of urban trees, and (4) the spatial distribution of urban vegetation and the individual tree delineation were assessed by validation samples and manual delineation results. The results showed that (1) both the random forest classification method and object-based classification method could extract urban vegetation accurately, with accuracies above 99%; (2) the watershed segmentation method based on the CHM could extract individual trees correctly, except for the small trees and the large tree groups; and (3) the individual tree segmentation based on point cloud data could delineate individual trees in three-dimensional space, which is much better than CHM segmentation as it can preserve the understory trees. All the results suggest that two- and three-dimensional urban vegetation extraction could play a significant role in spatial layout optimization and scientific management of urban vegetation.

Canopy disturbances over the five-century lifetime of an old-growth Douglas-fir stand in the Pacific Northwest

2002 ◽  
Vol 32 (6) ◽  
pp. 1057-1070 ◽  
Author(s):  
Linda E Winter ◽  
Linda B Brubaker ◽  
Jerry F Franklin ◽  
Eric A Miller ◽  
Donald Q DeWitt
Keyword(s):  
Pacific Northwest ◽  
Variable Density ◽  
Tsuga Heterophylla ◽  
Douglas Fir ◽  
Western Hemlock ◽  
Old Growth ◽  
The Pacific ◽  
History Of ◽  
Horizontal Heterogeneity ◽  
Restoration Strategies

The history of canopy disturbances over the lifetime of an old-growth Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) stand in the western Cascade Range of southern Washington was reconstructed using tree-ring records of cross-dated samples from a 3.3-ha mapped plot. The reconstruction detected pulses in which many western hemlock (Tsuga heterophylla (Raf.) Sarg.) synchronously experienced abrupt and sustained increases in ringwidth, i.e., "growth-increases", and focused on medium-sized or larger ([Formula: see text]0.8 ha) events. The results show that the stand experienced at least three canopy disturbances that each thinned, but did not clear, the canopy over areas [Formula: see text]0.8 ha, occurring approximately in the late 1500s, the 1760s, and the 1930s. None of these promoted regeneration of the shade-intolerant Douglas-fir, all of which established 1500–1521. The disturbances may have promoted regeneration of western hemlock, but their strongest effect on tree dynamics was to elicit western hemlock growth-increases. Canopy disturbances are known to create patchiness, or horizontal heterogeneity, an important characteristic of old-growth forests. This reconstructed history provides one model for restoration strategies to create horizontal heterogeneity in young Douglas-fir stands, for example, by suggesting sizes of areas to thin in variable-density thinnings.

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