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dc.contributor.advisor Jackson, Robert B. en_US
dc.contributor.advisor Wright, Justin P. en_US
dc.contributor.author Thorsos, Eileen Roseanne en_US
dc.date.accessioned 2012-01-12T13:38:31Z
dc.date.available 2012-01-12T13:38:31Z
dc.date.issued 2011 en_US
dc.identifier.uri http://hdl.handle.net/10161/5066
dc.description Thesis en_US
dc.description.abstract <p>Root carbon exudation is a critical element of the soil carbon cycle, and how both environmental conditions and plant traits influence exudation remains uncertain. I studied relationships between environmental conditions, plant traits, and carbon exudation in four herbaceous plant species: <italic>Asclepias incarnata</italic>, <italic>Microstegium vimineum</italic>, <italic>Panicum virgatum</italic>, and <italic>Scirpus cyperinus</italic>. Mature individuals were given short-term factorial light and N treatments, and exudates were collected from 8-hour carbon-free hydroponic incubations. I measured size traits (biomass, leaf area, root length, and root volume), photosynthesis (leaf-level and whole-plant), and tissue N traits (root, stem, and leaf percent N and C:N ratio). Neither light nor N treatments affected exudation, while exudation varied with species and traits. Species alone substantially explained mass-specific exudation (estimated R2 = 0.38). Size strongly predicted both total and mass-specific exudation, interacting with species (estimated R2 = 0.52 and 0.48, respectively). Generally, larger individuals exuded more overall but less per unit mass, although larger <italic>M. vimineum</italic> plants exuded more per unit mass. Whole-plant photosynthetic rate was weakly related to total exudation (estimated R2 = 0.17), and tissue N concentration moderately predicted mass-specific exudation (estimated R2 = 0.23). Other researchers have found that high light and low nitrogen availability stimulate exudation; my results indicate that this relationship is not straightforward. Plant traits, however, significantly explained variation in exudation, including some variation across species, supporting trait-based analyses of plant species' effects on ecosystem processes.</p> en_US
dc.subject Ecology en_US
dc.subject carbon exudation en_US
dc.subject functional traits en_US
dc.subject nitrogen en_US
dc.subject photosynthesis en_US
dc.title Functional Traits Exert More Control on Root Carbon Exudation than Do Short-Term Light and Nitrogen Availability in Four Herbaceous Plant Species en_US
dc.type Thesis en_US
dc.department Ecology en_US

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