Symptom development and mortality rates caused by
            Armillaria ostoyae
            in juvenile mixed conifer stands in British Columbia’s southern interior region

The coarse-scale population structure of pathogenic Armillaria (Fr.) Staude species was determined on approximately 16 100 ha of relatively dry, mixed-conifer forest in the Blue Mountains of northeast Oregon. Sampling of recently dead or live, symptomatic conifers produced 112 isolates of Armillaria from six tree species. Armillaria species identifications done by using a polymerase chain reaction based diagnostic and diploiddiploid pairings produced identical results: 108 of the isolates were Armillaria ostoyae (Romagn.) Herink and four were North American Biological Species X (NABS X). Five genets of A. ostoyae and one of NABS X were identified through the use of somatic incompatibility pairings among the putatively diploid isolates. Armillaria ostoyae genet sizes were approximately 20, 95, 195, 260, and 965 ha; cumulative colonization of the study area was at least 9.5%. The maximum distance between isolates from the 965-ha A. ostoyae genet was approximately 3810 m, and use of three estimates of A. ostoyae spread rate in conifer forests resulted in age estimates for the genet ranging from 1900 to 8650 years. Results are discussed in relation to possible mechanisms that influenced the establishment, expansion, and expression of these genets; the genetic structure and stability of Armillaria; and the implications for disease management in this and similar forests.

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Climate, radial growth, and mortality associated with conifer regeneration infected by root disease (Armillaria ostoyae)

The Forestry Chronicle ◽

10.5558/tfc2021-006 ◽

2021 ◽

Vol 97 (01) ◽

pp. 43-51

Author(s):

Michael P. Murray ◽

Adrian Leslie

Keyword(s):

Pseudotsuga Menziesii ◽

Radial Growth ◽

Pinus Contorta ◽

Mortality Rates ◽

Root Disease ◽

Economic Systems ◽

Larix Occidentalis ◽

Mortality Trends ◽

Armillaria Ostoyae ◽

Annual Mortality

Tree root disease caused by the pathogen Armillaria ostoyae (Romagn.) Herink has notable influence on bio-economic systems of southern British Columbia (BC) and the northwestern United States. Annual radial growth and mortality trends of regeneration associated with A. ostoyae during the first 21 years of a plantation were investigated. Our dendrochronological approach focused on a plantation established in 1991 with Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco), western larch (Larix occidentalis Nutt.), and lodgepole pine (Pinus contorta Dougl. ex Loud. var. latifolia Engelm. ex S. Wats.). We examined tree rings for reduced growth onset (RGO) to estimate infection periods. Among trees studied, we found that the number of RGO events peaked in 2006 followed by a steady decline in frequency. A similar trend was seen in annual mortality rates which reached maximum values in 2007 followed by an uninterrupted decrease. The average number of years from RGO to death based on host species ranged from 2.3 to 3.6 years. According to on logistic regression modeling, values associated with drought codes and duff moisture codes were significant in determining the year of death for infected trees. The predicted increase in frequency of summer droughts may lead to elevated mortality associated with A. ostoyae in young plantations.

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Tree mortality patterns following prescribed fires in a mixed conifer forest

Canadian Journal of Forest Research ◽

10.1139/x06-183 ◽

2006 ◽

Vol 36 (12) ◽

pp. 3222-3238 ◽

Cited By ~ 54

Author(s):

Leda Kobziar ◽

Jason Moghaddas ◽

Scott L Stephens

Keyword(s):

Sierra Nevada ◽

Ponderosa Pine ◽

Tree Mortality ◽

Fire Behavior ◽

Mortality Rates ◽

Fire Intensity ◽

Conifer Forest ◽

Mixed Conifer ◽

Mixed Conifer Forest ◽

White Fir

During the late fall of 2002 we administered three burns in mixed conifer forest sites in the north-central Sierra Nevada. Eight months later we measured fire-induced injury and mortality in 1300 trees. Using logistic regression, an array of crown scorch, stem damage, fuels, and fire-behavior variables were examined for their influence on tree mortality. In Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco), white fir (Abies concolor (Gord. & Glend.) Lindl.), and incense cedar (Calocedrus decurrens (Torr.) Florin), smaller trees with greater total crown damage had higher mortality rates. Smaller stem diameters and denser canopies predicted mortality best in ponderosa pine (Pinus ponderosa Dougl. ex P. Laws. & C. Laws). Duff consumption and bark char severity increased model discrimination for white fir and incense cedar and California black oak (Quercus kelloggii Newberry), respectively. In tanoak (Lithocarpus densiflorus (Hook. & Arn.) Rehd.), greater total crown damage in shorter trees resulted in higher mortality rates. Along with tree diameter and consumption of large (>7.6 cm diameter at breast height, DBH) rotten downed woody debris, fire intensity was a significant predictor of overall tree mortality for all species. Mortality patterns for white fir in relation to crown damage were similar among sites, while those for incense cedar were not, which suggests that species in replicated sites responded differently to similar burns. Our results demonstrate actual fire-behavior data incorporated into mortality models, and can be used to design prescribed burns for targeted reduction of tree density in mixed conifer forests.

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133: Comparisons of Prostate Cancer Mortality Rates with Changes in Dietary Practices in the United States from 1930 to 2000

The Journal of Urology ◽

10.1016/s0022-5347(18)32400-5 ◽

2006 ◽

Vol 175 (4S) ◽

pp. 42-43

Author(s):

Jan L. Colli ◽

Albert Colli

Keyword(s):

Prostate Cancer ◽

United States ◽

Cancer Mortality ◽

The United States ◽

Mortality Rates ◽

Dietary Practices ◽

Prostate Cancer Mortality

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Inequalities and Impact of Socioeconomic-Cultural Factors in Suicide Rates Across Italy

Crisis ◽

10.1027/0227-5910/a000084 ◽

2011 ◽

Vol 32 (4) ◽

pp. 178-185 ◽

Cited By ~ 15

Author(s):

Maurizio Pompili ◽

Marco Innamorati ◽

Monica Vichi ◽

Maria Masocco ◽

Nicola Vanacore ◽

...

Keyword(s):

Suicide Rate ◽

Age Groups ◽

Premature Death ◽

Mortality Rates ◽

Mortality Data ◽

Italian Population ◽

Comprehensive Overview ◽

Suicide Rates ◽

Younger Age ◽

Age And Sex

Background: Suicide is a major cause of premature death in Italy and occurs at different rates in the various regions. Aims: The aim of the present study was to provide a comprehensive overview of suicide in the Italian population aged 15 years and older for the years 1980–2006. Methods: Mortality data were extracted from the Italian Mortality Database. Results: Mortality rates for suicide in Italy reached a peak in 1985 and declined thereafter. The different patterns observed by age and sex indicated that the decrease in the suicide rate in Italy was initially the result of declining rates in those aged 45+ while, from 1997 on, the decrease was attributable principally to a reduction in suicide rates among the younger age groups. It was found that socioeconomic factors underlined major differences in the suicide rate across regions. Conclusions: The present study confirmed that suicide is a multifaceted phenomenon that may be determined by an array of factors. Suicide prevention should, therefore, be targeted to identifiable high-risk sociocultural groups in each country.

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