Life Sciences Commons^™

Disturbance And The Community Composition Of Arbuscular Mycorrhizal Fungi In Ontario Tallgrass Prairies, Sarah N. Allan

Electronic Thesis and Dissertation Repository

Arbuscular mycorrhizal fungi (Glomeromycota) form beneficial symbiotic relationships with the majority of land plants, especially in grasslands. Tallgrass prairies in Ontario are an endangered plant community currently being restored on former agricultural land. The objectives of my study were to determine if there were differences in the communities of Glomeromycota between disturbed and undisturbed tallgrass prairies in Ontario and if there were any potential indicator taxa for the ends of the disturbance spectrum. A molecular approach using DNA derived from soil samples was used to compare species composition between disturbed and undisturbed tallgrass prairies. A total of 177 operational taxonomic …

Fungi Associated With Common Buckthorn (Rhamnus Cathartica) In Southern Ontario, Nimalka M. Weerasuriya

Electronic Thesis and Dissertation Repository

Common buckthorn (Rhamnus cathartica) is a competitive Eurasian woody shrub currently invading North America. Buckthorn thickets reduce native diversity and may reduce mycorrhizal diversity through the release of allelochemicals. Two aspects of buckthorn’s invasional biology are explored: 1) identifying fungi associating with buckthorn, and 2) determining buckthorn’s allelochemical impacts on arbuscular mycorrhizae in forest soils and an open-greenhouse experiment.

Twenty-three fungi were found growing on buckthorn, including Armillaria mellea s.l., Hypoxylon fuscum, H. perforatum, Nectria cinnabarina, and Cylindrobasidium evolvens. Data from invaded and uninvaded sugar maple (Acer saccharum) soils revealed that arbuscular …