Albertas oil sands are located in the boreal forest where surface mining disturbs huge tracts of land. One such area, Syncrude Canada Ltd.s Mildred Lake mine, contains waste overburden (OB) piles which can be saline and sodic (SSOB). The objectives of this research were to 1) determine SSOB material impacts on planted tree root distributions, 2) quantify root activity to identify plant species growing at depth, and 3) document coarse woody root structure for planted trees. Root distributions for three mixedwood stands on reclaimed OB in relation to electrical conductivity (EC) and sodium absorption ratio (SAR) were examined using soil cores. Root distributions followed a similar pattern with soil depth as those from undisturbed boreal forest stands and appeared unaffected by the SSOB at this stage; however, future monitoring will be required as the stands mature. Root activity was assessed for jack pine (jP) and white spruce (wS) stands on tailings sand (TS) and OB using a strontium (Sr) chloride tracer. Understory and tree foliage was collected prior to and after application to measure Sr concentration in the control, broadcast, and depth treatments. A small proportion of roots grew in the OB material regardless of its chemical properties. Results from the Sr tracer study suggested that these roots were probably from the clover, sow thistle, and grasses. Planted trees showed little to no change in Sr tissue content suggesting that there were little to no roots in the treatment zones, the understory species out-competed the trees for Sr accessibility, or the tracer was diluted in the tree biomass to undetectable levels. Root systems of planted jP trees older than 10 years and older than 20 years on TS and OB were excavated and the number and diameter of lateral roots, the degree of kinking and coiling, and the presence of a taproot were recorded. Excavated trees showed poor taproot development on 70% of the trees and numerous root deformities, suggesting that more emphasis is needed in correct planting techniques and good planting stock to ensure proper root development. Roots are critical components of boreal forest ecosystems; without healthy root systems productivity may decline, stands may be susceptible to windthrow, and general forest health may suffer.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:SSU.etd-07042008-160353 |
| Date | 10 July 2008 |
| Creators | Lazorko, Heidi M. |
| Contributors | Van Rees, Ken C. J. |
| Publisher | University of Saskatchewan |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://library.usask.ca/theses/available/etd-07042008-160353/ |
| Rights | unrestricted, I hereby certify that, if appropriate, I have obtained and attached hereto a written permission statement from the owner(s) of each third party copyrighted matter to be included in my thesis, dissertation, or project report, allowing distribution as specified below. I certify that the version I submitted is the same as that approved by my advisory committee. I hereby grant to University of Saskatchewan or its agents the non-exclusive license to archive and make accessible, under the conditions specified below, my thesis, dissertation, or project report in whole or in part in all forms of media, now or hereafter known. I retain all other ownership rights to the copyright of the thesis, dissertation or project report. I also retain the right to use in future works (such as articles or books) all or part of this thesis, dissertation, or project report. |
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