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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

Causes of forest decline and consequences for oak-pine stand dynamics in southeastern Missouri /

Voelker, Steven L. January 2004 (has links)
Thesis (M.S.)--University of Missouri-Columbia, 2004. / Typescript. Includes bibliographical references (leaves 204-228). Also available on the Internet.
22

Causes of forest decline and consequences for oak-pine stand dynamics in southeastern Missouri

Voelker, Steven L. January 2004 (has links)
Thesis (M.S.)--University of Missouri-Columbia, 2004. / Typescript. Includes bibliographical references (leaves 204-228). Also available on the Internet.
23

Associations of Armillaria Root Disease in Jack Pine with <i>Arceuthobium Americanum</i>

Hebertson, Elizabeth G. 01 May 1995 (has links)
Relationships between jack pine dwarf mistletoe (Arceuthobium americanum Nutt. ex Engelm.) and Armillaria root disease (Armillaria ostoyae (Romagn.) Herink) were examined to determine how these two disease agents contribute to jack pine (Pinus banksiana Lamb.) decline and mortality in the Belair Provincial Forest, Manitoba, Canada. The incidence and extent of Armillaria root disease was strongly related to tree vigor. Dwarf mistletoe infection did not affect either the incidence of Armillaria or the mean percentage of root system colonization within vigorous, declining, and dead classes of trees. However, field observations and other analyses indicate that dwarf mistletoe was primary responsible for jack pine decline and mortality. In dwarf mistletoe mortality centers, Armillaria appeared to act opportunistically, extensively colonizing only the stressed trees. Analysis of distributions of percent Armillaria colonization revealed that rapid root system colonization occurred just prior to, or at the time of tree death.
24

Armillaria in Massachusetts Forests: Ecology, Species Distribution, and Population Structure, with an Emphasis on Mixed Oak Forests

Brazee, Nicholas Justin 13 May 2011 (has links)
The ecology, species distribution, and population structure of Armillaria was investigated in the forests of Massachusetts. From 64 plots at 16 sites, 640 isolates of Armillaria were collected from six forest types (northern hardwoods, mixed oak, pitch pine, white pine, white pine/mixed oak, and eastern hemlock). Armillaria gallica proved to be the most abundant species, making up 316/640 (52%) of all isolations. This was followed by A. solidipes (219/640; 34%), A. mellea (46/640; 7%), A. calvescens (36/640; 6%), A. gemina (16/640; 3%), and A. sinapina (7/640; 1%). Armillaria gallica was routinely encountered causing significant decay of the lower bole on living hardwood hosts, especially oaks. The population structure of 153 isolates of A. gallica collected from mixed oak forests was investigated using amplified fragment length polymorphisms (AFLPs). From a total sampling area of 4.51 ha, 38 AFLP genotypes were discovered, yielding a figure of eight genets per hectare with the average A. gallica genet occupying 0.13 ha. When the effects of hydrolyzable tannins on in vitro growth were compared between A. calvescens and A. gallica, it was A. gallica that appeared better at oxidizing and metabolizing commercial tannins (tannic acid and gallic acid) along with black oak root bark extracts. This was determined through measurements of colony area and dry biomass, and suggests that A. gallica may be a better adapted pathogen of oak. In order to more accurately distinguish between isolates of A. calvescens and A. gallica, a three-gene phylogeny was reconstructed, using partial sequences of the elongation factor 1-alpha (tef1), RNA polymerase II (rpb2) and nuclear large subunit (nLSU) genes. After comparing 12 isolates each of A. calvescens and A. gallica that originated from across northeastern North America, only the tef1 gene could accurately distinguish these two species. Five single nucleotide polymorphisms were present between the two species and maximum likelihood and maximum parsimony methods grouped A. calvescens and A. gallica into monophyletic clades.
25

Root rot in north-temperate forest stands : biology, management and communities of associated fungi /

Lygis, Vaidotas, January 2005 (has links) (PDF)
Diss. (sammanfattning). Uppsala : Sveriges lantbruksuniversitet, 2005. / Härtill 5 uppsatser.
26

Distribution of Heterobasidion and Armillaria root rots in Vallombrosa fir forest, Italy

Dálya, László Benedek January 2016 (has links)
This work intends to describe the present condition of Vallombrosa forest (Tuscany, Italy) from the phytopathological point of view. The chronic disease caused by Heterobasidion and Armillaria root rots is a key factor affecting the vitality of silver fir plantations of the region. Detailed knowledge about their distribution could help to control the pathogens. Systematic sampling and survey of damages on trees were undertaken at 52 points. Identification of different species from soil and fungal samples was accomplished by DNA-based methods (TSCP, nested PCR, RFLPs analysis). The high presence of both parasitic fungi was detected under a wide range of ecological conditions. Data analysis indicates the strong spreading potential of the pathogens even into new habitats, especially in connection with water stress of their hosts.
27

Analyse transcriptomique de deux souches fongiques québécoises Inonotus obliquus et Armillaria sinapina

Fradj, Narimane January 2019 (has links) (PDF)
No description available.
28

Actions of lignocellulolytic enzymes on Abies grandis(grand fir) wood for application in biofuel production

Cherdchim, Banyat 27 October 2010 (has links)
No description available.

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