Master of Science (MSc)
Faculty of Science
Increasing evidence indicates that plant community structure and therefore ecosystem function are mediated by below-ground fungal communities that form intracellular associations with plant roots called mycorrhizal associations. Arbuscular mycorrhizal fungi (AMF) are a type of mycorrhiza that colonize the plant host intracellularly but maintain hyphae outside the root cell for resource acquisition. The importance and function of AMF associations are well-documented in terrestrial ecosystems, but are less understood in aquatic or semi-aquatic systems. Phosphorus availability is the primary factor influencing mycorrhizal colonization and growth in terrestrial soils, with phosphorus-abundant soils leading to a decrease in mycorrhizal growth. However, the relationship between arbuscular mycorrhizal colonization and phosphorus supply in wetland systems is not well understood. Previous studies have examined this relationship, but have been limited by methodology and have indicated the need for studies closely mimicking natural conditions. To address this need, a field-based study was performed examining the mycorrhizal colonization of wetland plants growing in a natural wetland. Since field studies allow for only limited isolation and control of variables, a greenhouse study was also performed to isolate the impacts of phosphorus on mycorrhizal colonization in wetland plants. This study showed that phosphorus concentrations between 10 and 30 µg/L PO4-P are sufficient to alter mycorrhizal colonization in wetland plants, but the responses are species-specific. This variable impact on mycorrhizal colonization could induce species-specific responses in wetland plants, leading to shifts in community composition of wetland vegetation and ecosystem functioning.
Marshall, Daniel, "Quantifying relationships between phosphorus availability and mycorrhizal associations in wetland plants" (2017). Theses and Dissertations (Comprehensive). 1931.