An Alternate Indicator System for Nutrient Supply as Part of Ecosystem Function, a Component of Reclamation Success in the Athabasca Oil Sands Region

  • Author / Creator
    Hogberg, Jeffrey I.
  • Northeastern Alberta faces the challenges of reclaiming a vast area that has been disturbed my oil sands mining, cumulatively 896 km2 and increasing as of December 2013. The limited resources available for reclamation and expensive costs of undertaking the process necessitates that reclamation be as effective and efficient as possible in reaching its goal of establishing “equivalent land capability” to ecosystems that existed prior to disturbance. To achieve this goal, the best possible indicators of reclamation success should be used. Foliar macronutrient concentrations are commonly recommended as an indicator for soil nutrient levels in wildland ecosystems, but questions as to the validity and sensitivity of this indicator have been raised. This study measured the nutrient concentrations in three different pools of nutrients (soil, bioavailable, and foliar), on sites reclaimed using different reclamation treatments and on sites disturbed naturally by wildfire in order to determine if the current methods for indicating the success of establishment of nutrient cycling were valid and to determine if alternative systems of indicators could better identify differences between reclaimed and natural ecosites. The study was divided into two components: 1) Assessing the validity of the assumption that foliar nutrient concentrations were a useful indicator for belowground nutrient pools; and 2) Developing and demonstrating a different system for the assessment of similarity between sites’ nutrient profiles. 1) A study on CNRL’s Reclamation Area-1 (RA-1) compares whether trembling aspen (Populus tremuloides Michx.) foliar concentrations of macronutrients are an accurate representation of the bioavailable and soil nutrient pools in both natural and reclaimed forest ecosystems and if a multivariate similarity metric, rather than critical values for individual nutrients, could provide a more meaningful assessment of key differences between ecosystems. Individual macronutrient concentrations were different between treatments in the total soil nutrient pool, but differences decreased in the soil bioavailable pool and disappeared in the foliar nutrient pool. Few significant correlations between the foliar and belowground nutrient pools were observed. Multivariate analysis, consisting of non-metric multi-dimensional scaling and multiple response permutation procedures, showed a similar level of differences between natural wildfire-impacted reference sites and the reclaimed treatment sites across all three nutrient pools. Again, few significant multivariate correlations between foliar and belowground nutrient pools were observed. Comparison of the relative similarity of different reclamation treatments to the natural reference sites showed there are differences between the reclamation treatments not reflected by individual macronutrient levels. 2) A study on Syncrude Canada’s Aurora Soil Capping Study provided the opportunity to use principal components analysis to reduce data from trembling aspen and jack pine (Pinus banksiana Lamb.) foliar nutrient concentrations, and bioavailable and soil nutrients from both topsoil and upper subsoil to a minimum dataset that best represented the differences between a natural forest ecosystem and reclaimed ecosystems on sites capped with different topsoil materials and depths of subsoil material. The minimum dataset for this combination of site types was found to be differentiated by aspen foliar Mn, topsoil soil S, pine foliar Mn, pine foliar Ca, topsoil soil B, topsoil bioavailable Mg, topsoil soil total C, topsoil bioavailable Ca, aspen foliar Fe, upper subsoil soil B, upper subsoil bioavailable K, topsoil bioavailable Fe, topsoil bioavailable Pb, topsoil bioavailable Cu, topsoil bioavailable B, topsoil bioavailable Al, pine foliar K, and pine foliar Zn. Based on differences in these nutrients, the reclamation treatment of B/C blended subsoil (BCB) capped with forest floor-mineral mix (FFM) was most similar to the reference upland forest sites. Among treatments capped with peat-mineral mix (PM), a subsoil BCB horizon thickness of 70 cm was most similar to the reference site, followed by the 120 cm BCB and 30 cm BCB treatments.

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  • Type of Item
  • Degree
    Master of Science
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    This thesis is made available by the University of Alberta Libraries with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.