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Crow Lake


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Wandering River AB
Canada

Historical resources post-impact assessment, ATCO Electric, Ruth Lake-MacKay 240-kV transmission project and Crow and Gregoire 144 kV transmission projects, permit 2002-029


Year: 2002

Abstract:
The objectives of this post-impact assessment were to inventory historical resource sites within the development zone; evaluate the significance of the individual sites identified; assess the nature and magnitude of site specific impacts; and to design and implement an acceptable site specific mitigation program which would significantly eliminate potential future impacts to identified sites. Record review was conducted to identify previously recorded sites which could be affected by the development project, and to determine the nature of the database in the area. Ground reconnaissance was done to relocate, previously recorded historical resource sites as well as to identify and record any new sites within the development zone. Site discovery and post-impact assessment and included the visual examination of post-clearing surfaces within the right-of-way and inspection of adjacent exposures. Shovel testing was conducted in areas of identified cultural material or potential site areas lacking suitable exposures. The nature of the existing resource database, the quantity and quality of observable remains (e.g. site condition, content, uniqueness, and complexity) and the potential of the site to contribute to public enjoyment and education was evaluated. The areas targeted for this Historical Resources Post-Impact Assessment were portions of the Ruth Lake MacKay 240 kV Transmission Project and of the Crow and Gregoire 144 kV Transmission Projects, located in north-eastern Alberta. The Ruth Lake - MacKay Transmission Project is approximately 39 kilometres long, extending between the existing Ruth Lake Substation 848S (N1/2 16-92-10-W4M) and the new MacKay Substation (NW 5-93-12-W4M). The Crow Transmission Project is approximately 35 km long, extending between the new Crow Substation 860S and the existing Mariana Substation 833S. The Gregoire Transmission Project extends between the new Gregoire Substation 883S and an existing transmission line 7L36, with a total length of 15 km.

Post-fire compositional and functional recovery of western Canadian bogs


Author(s): Benscoter, B. W.

Year: 2007

Abstract:
Peatland ecosystems, which are predominantly found in northern boreal regions of Canada and Russia, accumulate carbon because photosynthetic production of the mosses dominating the ground layer exceeds their decomposition, thereby generating peat. Production and decomposition rates, and therefore peat accumulation, are species-specific. Therefore, changes in ground layer composition will have an effect on boreal peatland function.Fire is the most prevalent disturbance for boreal, western Canadian peatlands. Ombrotrophic, forested bogs are most affected by fire due to a drier peat surface relative to other peatland landforms and an extensive Picea mariana canopy. In addition to direct C losses during peat combustion, fire has indirect effects on bog C cycling through removal of the ground layer vegetation and alteration of the surface environment. Because peat accumulation varies among species, functional recovery post-fire is linked to ground layer succession, which varies with combustion severityTo assess the post-fire compositional and functional recovery trajectories of western Canadian bogs, I monitored the ground layer community structure, production, and decomposition from 2003 to 2006 along a chronosequence of historically burned bogs (1-106 years since fire). Ground layer succession was tri-phasic, grading from pioneer true mosses early post-fire (1-10 ysf) to a Sphagnum -dominated community (20-80 ysf), followed by feathermoss encroachment at the longest recovery times (>90 ysf). However, the ground layer biomass production trajectory was asymptotic, stabilizing at ca. 20 years post-fire and coinciding with Sphagnum dominance of the ground layer community. Decomposition in the upper peat column (top 40-cm) did not vary along the chronosequence.From my results, I developed models to assess the impact of an altered fire regime on peatland C storage. Increases in annual extent of wildfire and combustion severity under a 2xCO 2 scenario substantially extend the peatland C pool recovery time. Furthermore, other models suggest a substantial reduction of the fire return interval (< 70 yrs) will cause peatlands to become sources, rather than sinks, of atmospheric C. Warming will enhance this effect, requiring less of a reduction in fire interval to trigger the functional switch from carbon sink to source.

Remote sensing and analysis of forest environments


Author(s): Kachmar, M. A.

Year: 2004

Abstract:
High and medium resolution multispectral satellite imagery is used to classify live post-fire forest residuals within two large forest fire affected areas (>100,000 ha) in the northern boreal forest of Alberta, Canada. Residual forest patches are converted to polygons to calculate patch and shape metrics at nine minimum mapping unit classes. Results are analyzed and compared within and between the two fires. Results indicate how sensor spatial resolution, choice of MMU and anthropogenic features (i.e. highways, transmission lines) affect post fire residual patch and shape level metrics. The spectral angle mapper (SAM) classifier is used to classify forest cover on a highly industrialized mountain region in the central part of Honshu, Japan using Landsat TM 5 satellite imagery. Research findings relate land use and cover change (LUCC) processes on the mountain to image classification challenges. Findings illustrate the importance of calculating the spectral separability between forest cover types when developing a forest cover classification scheme in mountain regions where forest cover has been anthropogenically modified.

Citation: