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.

scholarly journals THE EFFECT OF SEVERAL VARIABLES ON THE SPECIFIC GRAVITY OF SECOND-GROWTH DOUGLAS FIR

1952 ◽  
Vol 28 (3) ◽  
pp. 34-44 ◽  
Author(s):  
R. W. Wellwood
Keyword(s):  
Specific Gravity ◽  
Site Index ◽  
Douglas Fir ◽  
Several Variables ◽  
Second Growth ◽  
Significant Difference ◽  
Thinning Operation ◽  
The Mean ◽  
Individual Trees ◽  
The University

Second-growth stands of mixed Douglas fir and western hemlock produce wood that varies considerably in quality, expressed as specific gravity, depending upon the factors of position in the stem, crown class and site index. Data were obtained from sample Douglas fir trees removed in a thinning operation on the University Research Forest, Haney, British Columbia. Samples represent three levels in the stem (stump, one-third total height and merchantable top), three major crown classes (Dominant, Codominant and Intermediate) and site indices from 93 to 160.It was determined that wood at the base of the tree was more dense than at the higher levels, although this difference failed to show significance for the better sites. Considering the differences, at the same levels, between trees of the three crown classes, Dominants had significantly lower values of specific gravity than either the Codominants or the Intermediates. No significant differences occurred between the latter two classes. When the variable of site is tested, it is found that the "Good" sites have significantly lower specific gravities than do the "Average" sites, for comparable sections. The interaction between site and crown class reveals that the differences above hold for the mean of all sites, and for "Average" sites, but that on "Good" sites no significant difference exists between any of the crown classes.In managing second-growth stands of this nature the forester should keep in mind the variation in specific gravity that will occur. He can regulate rate of growth of individual trees and of stands, within limits, so as to produce wood of the desired quality.

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.

scholarly journals GROWTH OF IMMATURE DOUGLAS FIR BY TREE CLASSES

1953 ◽  
Vol 29 (4) ◽  
pp. 367-373 ◽  
Author(s):  
J. W. Ker
Keyword(s):  
Growth Rate ◽  
Growth Rates ◽  
Douglas Fir ◽  
Radial Increment ◽  
Relative Growth ◽  
Stand Growth ◽  
Independent Variables ◽  
Second Growth ◽  
Individual Trees ◽  
Linear Regressions

This report outlines the results of a test of the value of the Tinney-Malmberg and the Schadelin systems of tree classification in estimating the growth rates of individual trees in second-growth stands of Douglas fir. Such tree classifications, that go beyond the recording of d.b.h. and crown class, are shown to increase the accuracy of tree description, at least in terms of probable growth-rate. The auxiliary classifications, i.e., "crown-sides-free" and "crown quality", appear to be almost equally effective in reducing errors in estimates of the rate of diameter growth.Multiple linear regressions were calculated to show the effect upon decadal radial-increment of the independent variables, d.b.h., crown class, and crown quality. Such relationships may provide (1) a guide to relative growth-rate of individual trees in drawing up tree-marking rules and (2) a basis for estimating gross current stand-growth.

The Red Neuronal Pigment in the Nervous System of the Mussel, Mytilus Edulis: Localization and Its Effect on Lateral Ciliary Activity with Spectral and Analytical Changes

1981 ◽  
Vol 39 ◽  
pp. 494-495
Author(s):  
Anthony A. Paparo ◽  
Judith A. Murphy
Keyword(s):  
Nervous System ◽  
Mytilus Edulis ◽  
Neuronal Cell ◽  
Ciliary Activity ◽  
Neuronal Cell Bodies ◽  
The Central Nervous System ◽  
Intracellular Organelles ◽  
The Common ◽  
The Individual ◽  
Cryostat Sections

The purpose of this study was to localize the red neuronal pigment in Mytilus edulis and examine its role in the control of lateral ciliary activity in the gill. The visceral ganglia (Vg) in the central nervous system show an over al red pigmentation. Most red pigments examined in squash preps and cryostat sec tions were localized in the neuronal cell bodies and proximal axon regions. Unstained cryostat sections showed highly localized patches of this pigment scattered throughout the cells in the form of dense granular masses about 5-7 um in diameter, with the individual granules ranging from 0.6-1.3 um in diame ter. Tissue stained with Gomori's method for Fe showed bright blue granular masses of about the same size and structure as previously seen in unstained cryostat sections.Thick section microanalysis (Fig.l) confirmed both the localization and presence of Fe in the nerve cell. These nerve cells of the Vg share with other pigmented photosensitive cells the common cytostructural feature of localization of absorbing molecules in intracellular organelles where they are tightly ordered in fine substructures.

Exploration of Endophytes from Alfalfa (Medicago sativa L.) as Biocontrol Agents

2020 ◽  
pp. 1-8
Author(s):  
Beilei Wu ◽  
Beilei Wu ◽  
Mei Li ◽  
Xiaoli Chen ◽  
Xiliang Jiang ◽  
...  
Keyword(s):  
Medicago Sativa ◽  
Root Rot ◽  
Agricultural Production ◽  
Biocontrol Agents ◽  
Bacillus Spp ◽  
Medicago Sativa L ◽  
The Common ◽  
Seedling Germination ◽  
Germination Experiments ◽  
Alfalfa Root

Endophytes are increasingly investigated as biocontrol agents for agricultural production. The identification of new endophytes with high effectiveness against plant disease is very important. A total of 362 strains of endophytes, including fungi, bacteria, and actinomycete, were isolated from alfalfa (Medicago sativa L.) collected in Hebei, Inner Mongolia and Ningxia provinces of China. The three strains of endophytic bacteria (NA NX51R-5, NA NX90R-8, and NA NM1S-1) with strong biocontrol capability with >50% effectiveness were screened against the common alfalfa root rot pathogen Fusarium oxysporum F. sp. medicaginis in alfalfa seedling germination experiments on MS medium and pot experiments. Using phylogenetic analysis, the isolates of NA NM1S-1 and NA NX51R-5 were identified as Bacillus spp. by 16S rDNA, while NA NX90R-8 was found to be Pseudomonas sp.

What Can Economists Contribute to the Common Good Tradition?

2017 ◽  
Author(s):  
Andrew M. Yuengert
Keyword(s):  
Common Good ◽  
Common Pool Resources ◽  
Economic Approach ◽  
Public And Private ◽  
Private Provision ◽  
The Public ◽  
The Common Good ◽  
The Common ◽  
The Individual ◽  
Insight Into

Although most economists are skeptical of or puzzled by the Catholic concept of the common good, a rejection of the economic approach as inimical to the common good would be hasty and counterproductive. Economic analysis can enrich the common good tradition in four ways. First, economics embodies a deep respect for economic agency and for the effects of policy and institutions on individual agents. Second, economics offers a rich literature on the nature of unplanned order and how it might be shaped by policy. Third, economics offers insight into the public and private provision of various kinds of goods (private, public, common pool resources). Fourth, recent work on the development and logic of institutions and norms emphasizes sustainability rooted in the good of the individual.

Punk as Folk: Continuities and Tensions in the UK and Beyond

2020 ◽  
Author(s):  
Pete Dale
Keyword(s):  
Folk Music ◽  
Music Making ◽  
Collective Creativity ◽  
Living Tradition ◽  
Wide Range ◽  
The Us ◽  
The Common ◽  
The Individual ◽  
The Uk

Numerous claims have been made by a wide range of commentators that punk is somehow “a folk music” of some kind. Doubtless there are several continuities. Indeed, both tend to encourage amateur music-making, both often have affiliations with the Left, and both emerge at least partly from a collective/anti-competitive approach to music-making. However, there are also significant tensions between punk and folk as ideas/ideals and as applied in practice. Most obviously, punk makes claims to a “year zero” creativity (despite inevitably offering re-presentation of at least some existing elements in every instance), whereas folk music is supposed to carry forward a tradition (which, thankfully, is more recognized in recent decades as a subject-to-change “living tradition” than was the case in folk’s more purist periods). Politically, meanwhile, postwar folk has tended more toward a socialist and/or Marxist orientation, both in the US and UK, whereas punk has at least rhetorically claimed to be in favor of “anarchy” (in the UK, in particular). Collective creativity and competitive tendencies also differ between the two (perceived) genre areas. Although the folk scene’s “floor singer” tradition offers a dispersal of expressive opportunity comparable in some ways to the “anyone can do it” idea that gets associated with punk, the creative expectation of the individual within the group differs between the two. Punk has some similarities to folk, then, but there are tensions, too, and these are well worth examining if one is serious about testing out the common claim, in both folk and punk, that “anyone can do it.”

scholarly journals Subtype Characterization and Zoonotic Potential of Cryptosporidium felis in Cats in Guangdong and Shanghai, China

Pathogens ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 89
Author(s):  
Jiayu Li ◽  
Fuxian Yang ◽  
Ruobing Liang ◽  
Sheng Guo ◽  
Yaqiong Guo ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Phylogenetic Analysis ◽  
Genetic Characterization ◽  
Zoonotic Potential ◽  
Common Occurrence ◽  
High Genetic Diversity ◽  
Gp60 Gene ◽  
The Common ◽  
Subtyping Tool

Cryptosporidiumfelis is an important cause of feline and human cryptosporidiosis. However, the transmission of this pathogen between humans and cats remains controversial, partially due to a lack of genetic characterization of isolates from cats. The present study was conducted to examine the genetic diversity of C. felis in cats in China and to assess their potential zoonotic transmission. A newly developed subtyping tool based on a sequence analysis of the 60-kDa glycoprotein (gp60) gene was employed to identify the subtypes of 30 cat-derived C. felis isolates from Guangdong and Shanghai. Altogether, 20 C. felis isolates were successfully subtyped. The results of the sequence alignment showed a high genetic diversity, with 13 novel subtypes and 2 known subtypes of the XIXa subtype family being identified. The known subtypes were previously detected in humans, while some of the subtypes formed well-supported subclusters with human-derived subtypes from other countries in a phylogenetic analysis of the gp60 sequences. The results of this study confirmed the high genetic diversity of the XIXa subtype family of C. felis. The common occurrence of this subtype family in both humans and cats suggests that there could be cross-species transmission of C. felis.

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