Functional Traits Exert More Control on Root Carbon Exudation than Do Short-Term Light and Nitrogen Availability in Four Herbaceous Plant Species
| dc.contributor.advisor | Jackson, Robert B | |
| dc.contributor.advisor | Wright, Justin P | |
| dc.contributor.author | Thorsos, Eileen Roseanne | |
| dc.date.accessioned | 2012-01-12T13:38:31Z | |
| dc.date.available | 2012-01-12T13:38:31Z | |
| dc.date.issued | 2011 | |
| dc.department | Ecology | |
| dc.description.abstract | 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: Asclepias incarnata, Microstegium vimineum, Panicum virgatum, and Scirpus cyperinus. 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 M. vimineum 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. | |
| dc.identifier.uri | ||
| dc.subject | Ecology | |
| dc.subject | carbon exudation | |
| dc.subject | Functional traits | |
| dc.subject | Nitrogen | |
| dc.subject | Photosynthesis | |
| dc.title | Functional Traits Exert More Control on Root Carbon Exudation than Do Short-Term Light and Nitrogen Availability in Four Herbaceous Plant Species | |
| dc.type | Master's thesis |
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