Aria Hahn, MSc candidate Soil Science (Supervisor Dr Sylvie Quideau), Renewable Resources, will present a seminar on 25 November 2011 at 8:30 am in 802 General Services Building, University of Alberta campus.
Abstract: Microbial communities are responsible for biogeochemical processes in soils such as nutrient cycling and organic matter formation, which are essential to the establishment of vegetation and ecosystem sustainability. Phospholipid fatty acid analysis, microbial respiration and enzymatic activities were used to assess the development of soil microbial communities in two early ecosystems: along a 99 year glacial chronosequence at Mount Robson Provincial Park, and in reconstructed soils in the Canadian boreal forest following open-pit mining. In the glacial environment, plant-microbe interactions took 40 years to become established as yellow mountain avens had a measurable effect on soil microbial biomass only in the mid-successional stage. Overall, increased microbial biomass, enzyme activity and substrate respiration along the chronosequence, as well as significant correlations between the microbial respiration and percent soil N indicated that the soil microbial community was responding to changes in the soil environment. In the reconstructed soils, the use of organic forest floor amendments originating from the target upland forest ecosystem placed both the vegetation and soil microbial community on a faster trajectory towards ecosystem recovery than did the use of alternative peat amendments. Additionally, the vegetation on the plots reclaimed with forest floor was more similar to the natural reference stand than was the vegetation on the peat-reclaimed plots. Thus, the accelerated development of the “natural”, or target, soil microbial communities observed on the plots reclaimed with forest floor may be linked to the similarities in plant communities found between these plots and the natural forest reference stand.