Marie Claude Roy (Ph.D. In Progress) Started: 2008 Thesis Title: Wetland Plant Community Dynamics through Time: a Comparison between Natural and Reclaimed Wetlands Affected by Oil Sands Mining.

Project Summary: In past years, pilot projects have been conducted by the oil sands industry in an effort to construct wetlands in post-mined areas. These projects have focused on creating three wetlands types that differ in the substrate materials used:

1) wetlands constructed directly on mineral substrates (un-amended).
2) wetlands whose substrates have been covered (amended) with a layer of oil sands tailings.
3) wetlands whose substrates have been amended with a layer of peat topsoil.

Each type of reclaimed wetland substrate is thought to differently influence the establishment and development of biota. Marie Claude is comparing the development and succession of wetland plant communities through time in both reclaimed and natural wetlands in northeastern Alberta. The study of vegetation dynamics in natural wetlands will be used as a model to which restored vegetation dynamics will be compared to assess the success of reclamation efforts.

Past Graduate Students & Postdoctoral Fellows
 

Project Summary: Physiological performance of Typha latifolia plants growing in oil sands‑affected wetlands.
Oil sands companies attempt to reclaim peat‑accumulating wetlands in the mined landscape despite water chemical conditions that exceed tolerance limits of most peat‑forming species. Typha latifolia is a target species for reclamation as it spontaneously establishes in ponds affected by oil sands mining. This work incorporated the variability of wetlands found in the oil sands leases and pristine natural areas in the region thus complementing previous studies in T. latifolia (Bendell‑Young et al., 2000; Crowe et al., 2001; Hornung et al., 2006). We are comparing the physiological (leaf fluorescence and gas exchange rates) and morphological performance of T. latifolia populations growing in six industrial (affected by effluent or tailings), six indirectly affected (without direct pollution inputs), and six natural (off‑site) wetlands. T. latifolia plants established in oil sands wetlands have similar photosynthesis rates to plants from natural wetlands. Oil sands‑affected populations register lower transpiration, quantum yield of PSII, leaf lengths and number of green leaves per plant than populations from natural wetlands. However, we have found no significant differences in the performance parameters measured of T. latifolia plants growing in industrial wetlands compared to plants growing in indirectly­­-affected wetlands. This lack of differences is due to high variability in plant performance among oil sands-affected wetlands.  Typha latifolia plants in oil sands‑affected wetlands apparently have a restricted growth that might affect carbon assimilation at the stand level.
 

Kurt Frederick (M.Sc.) Completed: 2010 Thesis Title: Productivity and carbon accumulation potential of transferred biofilms in reclaimed oil sands-affected wetlands.

Thesis Abstract: Biofilms are significant contributors to primary production, nutrient cycling, bio‑stabilization and the food web of wetland ecosystems. Photoautotrophic biomass (PB) and primary production (PP) were determined for biofilms exposed to various treatments and materials in wetlands near Fort McMurray. Biofilm additions and oil sands process‑affected materials were expected to increase the microbial colonization rates on treated substrates and subsequently PB and PP of biofilms over time as compared to controls and unaffected materials. Biofilms survived the transfers and colonized new substrates immediately. Oil sands process affected materials were found to increase PB and PP throughout the first year. A strong decreasing trend for both PB and PP in treatment microcosms occurred in year two, eventually coalescing with control conditions at a lower equilibrium. Transferred biofilms and treatment materials, therefore, increased overall wetland productivity during the initial stages of wetland development when growing conditions are most limiting.

Jonathan Hornung (Postdoctoral fellow) Completed: 2006 Research focus: Ecosystem function in oil sands wetlands: rates of detrital decomposition and moss growth (with C. Wytrykush).

Thesis Abstract: Decomposition of dead plant material is an integral process providing key nutrients to drive primary productivity in wetlands.  How rapidly aquatic plant matter is broken down within a wetland can indicate the potential for productivity and, by extension, the adequate functioning of aquatic ecosystems. In contrast, the sequestration of incompletely decomposed materials ultimately results in organic matter production, potentially supporting the development of fens and bogs. The purpose of this project is to examine the effects of four factors on cattail and moss decomposition in constructed and natural wetlands, 1) oil sands process sediments (present/ absent) and 2) oil sands process water (present/ absent), 3) wetland age (younger vs. older), and 4) sediment organic content (low‑unamended/high‑amended).  We expect all vegetative material to exhibit exponential decay over time.  Cattail decomposition will be more rapid than moss decomposition.  For both types of vegetation, decomposition will be slowed by the presence of oil sands process materials.

Lynnette Dagenais (M.Sc.) Completed: 2008 Thesis Title: Postmining habitats and breeding birds in the Athabasca oil sands region

Thesis Abstract: The Athabasca Oil Sands Region of northeastern Alberta is being rapidly developed. Wetland and terrestrial guild abundances, species richness, and nest success were evaluated to understand the effects of oil sands by‑product waste and the replacement of natural habitats with post‑mining habitats across 11 sites in 2006 and 2007. Although most relationships between dependent and independent variables were weak, avian guilds were positively associated with the amount of suitable nesting habitat. The presence of forest cover was positively associated with tree‑nesters and species richness. Species richness and avian community composition on the Suncor lease site from 1976 to 1983 was also compared with 2006 and 2007 data. Avian species richness was significantly lower during 2006 and 2007. Avian community composition was also different between these two time periods. Cavity, tree-, water- and other substratenesters experienced the highest decline in richness.