The Athabasca oil sands region in northeastern Alberta is the largest single oil reserve in the world with an estimated one trillion barrels of bitumen. Much of the oil is extracted by large scale surface mining which represents a disturbance parallel in magnitude to glaciation. Decommissioned mines are reclaimed with a combination of stock-piled substrates, laid out in artificial horizons, creating Anthrosols. The land reclamation treatments examined here consist of a salvaged peat-mineral mix overlying horizons of mineral materials such as tailings sand, lean oil sand and Pleistocene clay.

The objective of this project is to examine the development of ecosystem function as it relates to microbial community structure and nutrient availability. Our hypotheses are that nutrient availability will vary more greatly than microbial community structure, and that site, slope position and season will cause more variability than early developmental time.

To examine nutrient availability we installed plant root simulator (PRS) probes, which consist of resin membranes that adsorb ions from the soil solution, similarly to plant roots. We used phospholipid fatty acid (PLFA) analysis to examine the microbial community as this method has been extremely useful in monitoring shifts in community structure measured over time. Replicate samples were taken from three slope positions at three sites on three dates (June and August 2005, and August 2006) and non-metric multi-dimensional scaling (NMS) was used to examine trends in the data set. Preliminary results indicate that year, site and season affect variability in both soil nutrient availability and microbial community structure more so than slope position, peat type and age. A lack of vegetation at one of the sites is also an extremely important factor in driving nutrient fluxes.