The Race for Rhizobia: An investigation into the symbiotic capabilities of Fabaceae with rhizobia in nitrogen-deficient, disturbed urban soils

Abstract

Canadian citizens who reside in urban centres benefit from well-functioning urban vegetative communities because they provide ecosystem services that boost quality of life. However, healthy vegetative community development is only possible with productive soils; within cities, there tends to be disturbed, nutrient-limited soils that may not provide suitable foundations for complex vegetative community establishment. Disturbed urban soils in many cases have lost their uppermost horizons, and have significant nitrogen deficiencies which bring forth recolonization challenges for native vegetation. Fabaceae plants, with rhizobial symbionts, offer a sustainable reclamation solution through nitrogen fixation. Though, an issue with using Fabaceae involves the widespread application of their genus-specific inoculants when introducing them into an area. It’s mainly understood that when planting Fabaceae, an important step is to inoculate the seeds prior to introduction to ensure that their specific microbial friends are present along with them when they begin to grow. Edmonton's disturbed soils have exhibited low microbial presence, but we are unsure if rhizobia specifically are low in abundance. There have been very few studies conducted here in Edmonton that have asked whether these bacteria are already present in our disturbed soils in numbers that allow for effective nodulation in Fabaceae. If we find they are, we can potentially eliminate the cost of inoculation in reclamation.

Department: Biological Sciences

Faculty Mentor: Dr. Karen Christensen-Dalsgaard