We are pleased to announce that Kiran Preet Padda successfully defended her examination for the degree of Doctor of
Philosophy in Soil Science on May 28, 2020!
Characterizing the beneficial ecological association of endophytic bacteria with lodgepole pine trees naturally-regenerating at unreclaimed gravel mining pits
Gravel mining operations are responsible for extensive degradation of forest ecosystems. Due to the complete removal of vegetation and topsoil, which results in the loss of essential plant-nutrients, natural plant succession is extremely slow in such disturbed ecosystems. However, despite such severe conditions, lodgepole pine trees are growing vigorously at gravel mining pits in the central interior of British Columbia, raising questions regarding the source of their nutrient-inputs. In this thesis, the role of endophytic bacteria (bacteria living within plant tissues) in supporting pine tree growth was explored. These bacteria were able to fix significant amounts of nitrogen from the atmosphere (up to 53%) for pine trees and stimulate their growth under nutrient-stress. Additionally, these bacteria demonstrated considerable potential to acquire phosphorus and iron and modulate plant hormone-levels. This research shows that lodgepole pine trees may associate with beneficial endophytic bacteria as a survival-strategy to thrive on highly disturbed gravel pits and such bacteria have significant potential to be used as a sustainable reclamation tool.