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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.
1

Resistance in Salix against willow leaf rust caused by Melampsora epitea /

Johansson, Leif, January 1900 (has links) (PDF)
Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniv. / Härtill 4 uppsatser.
2

Distribution and seasonal variation of macro-nutrients, starch and radio-nuclides in short rotation Salix plantations /

Fircks, Yuehua von. January 1900 (has links) (PDF)
Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniv., 2001. / Härtill 4 uppsatser.
3

Accumulation and mobilisation of nutrient reserves in Salix viminalis /

Bollmark, Lars, January 1900 (has links) (PDF)
Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniv. / Härtill 4 uppsatser.
4

The fate of deposited 15N in a plant-soil mesocosm

Wang, Wenwen. January 2007 (has links)
Thesis (M.S.)--State University of New York at Binghamton, Biological Sciences Department, 2007. / No. "15" in title is in superscript, or elevated, position. Includes bibliographical references.
5

Pilodling till användning inom trädgård och hantverk : med tonvikt på zon 5

Ekman, Linda January 2013 (has links)
Syftet med det här examensarbetet är att undersöka hur pil, eller mer specifikt, sorter inom släktet Salix sp. odlas för användning inom hantverk och trädgård. Bland dessa sorter kan nämnas korgvide (Salix viminalis). Denna typ av odling är småskalig och syftet är att få material till flätning av exempelvis korgar eller grövre arbeten som hägn och staket i trädgård. Materialet som används är vanligen ettåriga skott av odlade pilsorter som skördas när plantan är i vintervila. Därefter torkas skotten i ca 6 månader för att sedan blötläggas innan flätningen påbörjas. Blötläggningen gör pilskotten mjuka och böjliga. Pil kan även användas färsk till att skapa levande hägn genom att pilskott sticks ner i jorden och får rota sig.   I detta arbete finns information om hur man kan gå tillväga för att anlägga och sköta en pilodling samt vilka markförhållanden och skötselmetoder som krävs. Fakta har samlats in genom att studera litteratur inom området, studiebesök samt mailkontakt med pilodlare. Här finns även en sammanställning av pilsorter som är härdiga att odla i zon 5.   Även odling av Salix sp. för användning till biobränsle, s.k. energiskog har studerats. Anledningen till detta är att dessa odlingar, som även kallas salixodlingar, till stor del består av ovan nämnda sort korgvide (S. Viminalis). Då det har forskats mycket inom detta område har informationen varit av nytta både vad det gäller odlingsbetingelser och härdighet för Salix sp.   Slutsatsen är att tillräckligt mycket information har hittats för att svara på syfte och frågeställningar. Fakta från energiskogsodlingen har inom vissa områden gett vägledning om hur skötsel av en småskalig odling kan förbättras. Även kommunikationen med verksamma pilodlare har lyft fram förslag till förbättringar.
6

Evaluation des capacités biotechniques de boutures de Salicaceae et Tamaricaceae sur un gradient de sécheresse / Biotechnical capabilities evaluation of Salicaceae and Tamaricaceae cuttings according to drought gradient

Lavaine, Catherine 12 November 2013 (has links)
Le phénomène naturel d’érosion des berges peut menacer des infrastructures humaines. Des protections végétales peuvent être installées afin de mimer les dynamiques de végétation et armer la berge grâce aux racines. Cependant, les changements climatiques globaux sont susceptibles d’entraîner et d’aggraver les sécheresses, ce qui va stresser les végétaux présents et compromettre la bonne réussite des ouvrages de génie végétal. La principale question est donc « Quelles sont les caractéristiques biotechniques et les facultés d’acclimatation à la sécheresse de boutures de Salicaceae et Tamaricaceae, espèces utilisées ou potentiellement utilisables en génie végétal ? ». L’étude de différentes populations d’espèces classiquement utilisées que sont les saules démontre une résistance à la sécheresse plus efficace des populations méridionales tandis que les productions de biomasses restent plus élevées chez les populations septentrionales. L’étude des traits biotechniques et du comportement racinaire d’espèces potentielles appartenant aux Tamaricaceae (Tamarix gallica et Myricaria germanica) montre un taux élevé de reprise au bouturage, une forte production de biomasses et une stratégie de prospection racinaire différente des saules, ce qui leur confère une résistance à la sécheresse accrue. Ceci confirme une utilisation possible de ces espèces dans des ouvrages de génie végétal soumis à sécheresse. / The natural phenomenon of riverbank erosion can threaten human stakes. Vegetative bioengineering protections can be installed to imitate the vegetation dynamics and anchor the soil bank thanks to roots. However, global climate change could induce and increase droughts, what is going to stress plants and to compromise the bioengineering works success. The main question is thus " what are the biotechnical capabilities and the drought acclimatization faculties of cuttings of Salicaceae and Tamaricaceae, species used or potentially useful in bioengineering? ". The study of different populations of species such as willows demonstrates a more effective drought resistance of the Southern populations whereas the biomass productions remain higher with the Northern populations. The study of the biotechnical traits and the root behavior potentially useful species such as Tamaricaceae (Tamarix gallica and Myricaria germanica) show a high resprouting rate, a high biomass production and a prospecting root strategy different from willows. This results confer them a better drought resistance. This confirms a possible use of these species in vegetative bioengineering works subjected to drought.
7

Irrigation and Seeding Technique Development for Riparian Corridor Habitat Revegetation

Grabau, Matthew Robert January 2009 (has links)
Revegetation of riparian tree species along the lower Colorado River is currently a major activity for federal and state agencies. Revegetation methods for Fremont cottonwood (Populus fremontii), Goodding's willow (Salix gooddingii), and coyote willow (S. exigua) have historically consisted of cutting collection and vegetative propagation. If direct seeding could be implemented, large cost-savings could be realized while enhancing restoration results due to increased genetic and structural diversity. The following documents laboratory, greenhouse, and field studies conducted to establish seed storage practices, irrigation techniques, and seeding methods and rates which maximize germination and growth rates of these riparian tree species. Experimental seed storage study results indicated that seed viability was maintained for at least a two-year window by freezing, during which seed can be utilized for direct seeding or seedling production. Greenhouse study results include: (1) seed cleaning resulted in higher tree establishment; (2) adverse soil conditions reduced growth rates; (3) organic fertilizer amendment mitigated negative effects of sandy soil for Fremont cottonwood but not for willow; (4) mixed seeding resulted in cottonwood dominance, indicating that reduced rates or separate seeding of this species might be required to improve success of willow species seeding. Small-scale field study results include the following: (1) Fremont cottonwood establishment averaged 7% of pure live seed rates, whereas willow species establishment was less than 1%; (2) sprinkler irrigation did not affect establishment, and decreased tree growth rates; (3) hydroseeding resulted in higher canopy cover, establishment, and above-ground biomass compared to broadcast seeding for all three species; (4) furrow or border irrigation did not affect Fremont cottonwood or coyote willow establishment, but furrow irrigation resulted in higher Goodding's willow establishment. Volunteer species were abundant, with grasses dominating cover and biomass after one growing season despite application of grass specific herbicide. Saltcedar (Tamarix ramosissima) also established in abundance, but grew slower than Fremont cottonwood during the first growing season. Monitoring after three growing seasons indicated higher growth rates and survival of Fremont cottonwood compared to volunteer species. Larger-scale seeding studies are required to refine establishment rates and determine the cost-effectiveness of direct seeding for large-scale Salicaceae species revegetation.
8

Till en älskad vän : materia och objekt som medier för överföring

Auran Frankenstein, Karin January 2014 (has links)
With self-hypnosis as a method, I work with levels of consciousness in relation to practice. Focus lies in the relation between a language of materials and an inner experience. How do material expressions function as mediums of a spiritual matter between a beholder and me? The trance functions as a space for a spiritual contact/communication. Abstract images of crystalline glaze on ceramic tiles are direct results of these acts. The work also includes sculptural furniture of Salix, so called “energy forest” and a film-­‐documentation of Ma Stjärnliden, a medium. The energy chairs holds both function and symbolic implications to the integrality, the film widens the theme by stretching towards the occult as well as the mediumistic communication represents an extreme variant of consciousness. The three works experienced together, in addition to shape, form and function offers an entrance into a spiritual space. This written material describes, background, methods, process, materials, aesthetics and embedded symbolic references as well as it presents an analysis of a contemporary context to widen the spiritual as a theme.
9

Ecological and molecular studies of fungal communities associated with roots of <i>Salix spp.</i> grown under high density, short rotation intensive culture

Corredor, Aura Helena 22 February 2011
In Canada, willow (Salix spp.) short rotation intensive cultures (SRIC) have been established to investigate their potential to produce biomass for bioenergy. Since root-associated fungal communities are involved in plant nutrition and disease susceptibility, it is relevant to understand their interactions with willows and their role on the sustainability of SRIC. In this project traditional methods together with molecular techniques were used to: i) assess the diversity of fungal communities in roots of willows and their relationship with major characteristics of SRIC ii) evaluate the effects on plant development of potentially beneficial and pathogenic fungi, and iii) identify arbuscular mycorrhizal fungal (AMF) species and their interaction with promising Salix clones. Potentially pathogenic fungi were more dominant in diseased and recently planted cuttings than in healthy older ones. This suggested the occurrence of a positive shift prompted by the establishment of the cuttings on the site. Gibberella/Fusarium sp. and Neonectria sp. were the most dominant taxa particularly in diseased plants. Under greenhouse conditions the inoculation with potentially beneficial and potentially pathogenic fungi induced significant differences in root biomass but not in overall aerial biomass production. PCR-denaturing gradient gel electrophoresis was successfully standardized and used to identify arbuscular mycorrhizal fungal species associated with different clones. The results indicated a degree of specificity between AMF species and plant genotype. Root-associated fungal communities appear to be useful to monitor the impacts of SRIC on soil ecology and their study may enlighten effective ways to increase the productivity of these biomass systems.
10

DNA fingerprinting and genetic relationships among willow (<i>Salix</i> spp.)

Ngantcha, Alain Claude 15 April 2010
Given that morphological identification of willow is difficult, willow lines being investigated for their suitability for use as short rotation crops for biomass production in Saskatchewan were investigated with various molecular techniques as possible tools for DNA fingerprinting. Flow cytometry was used to assess variation in nuclear DNA content and thus ploidy level of the lines of the five species (<i>Salix purpurea, Salix eriocephala, Salix sachalinensis, and Salix dasyclados</i>) and three hybrids (<i>S. purpurea x S. miyabeana, S. sachalinensis x S. miyabeana, S. viminalis x S. miyabeana</i>). The DNA content varied between 1.14 and 3.00pg. Ploidy levels of the species varied from triploid to hexaploid while all hybrids were tetraploid. RAPD and ISSR marker systems were used to assess genetic and taxonomic relationships among all willow lines. Of 90 RAPD primers tested, 60 were selected and 99 polymorphic bands scored. Of 35 ISSR primers tested, 19 were selected and 35 polymorphic bands scored. Both RAPD and ISSR dendrograms clustered together lines belonging to the same species and same hybrid combination. A combination of strong and reproducible RAPD and ISSR bands was used to develop identification keys for lines belonging to the same species.<p> The ribosomal RNA gene region, including the entire 5.8S RNA gene and the internal transcribed spacers (ITS1 and ITS2) was amplified and sequenced to assess sequence homology between the five species. The total length of the amplified region was 601bp, with the ITS1, 5.8 S and ITS2 being 223, 163, and 215bp respectively. Intra- and inter-species SNPs were observed, 6 within ITS1, and 3 within ITS2. No polymorphisms were found in the 5.8S gene. The low rate of variation within the sequenced ITS fragment between species supports the monophyly of the five species involved in this study, and confirms their belonging to the subgenus Caprisalix. SCAR primers were designed from species-specific polymorphic nucleotides and applied to the willow collection to test their use for species identification. A species identification key based on SNPs is proposed.

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