Landscape Changes
Human activities can leave landscape features that arepresent for a long time. These can impact the natural environment in many ways. Linear features such as roads, power transmission lines, seismic lines and pipelines create new corridors that influence human and animal movement patterns.
Permanent features are expected to remain noticeable on the landscape into the foreseeable future, although they could be reclaimed.
Semi-permanent features are usually those that are maintained by humans on the landscape. This category includes features such as roads, power transmission lines, pipelines, power dams, and land used for agriculture.
Temporary Features can remain noticeable for some time, but are not maintained by humans, and are generally left to natural regeneration. They including seismic lines and commercial forest harvesting areas, Depending on the type of vegetation impacted, some areas return to their previous vegetation type quickly, and others take a longtime to regenerate.
Compared to jurisdictions in southern Canada, human-caused landscape changes in the Northwest Territories have been relatively small, but still are measurable. As more infrastructure and renewable and non-renewable resources are developed in the NWT, management agencies are increasing capacity to monitor cumulative impacts. Multiple organizations including government, First Nations and industry are working together to develop coordinated mechanisms for tracking and reporting on landscape changes. Landscape changes that are not due to human activities, such as changes caused by climate and most forest fires, are found in the other focal points CLIMATE, VEGETATION, PERMAFROST.
This indicator measures the total length and density of semi-permanent linear features, such as transmission lines, winter roads, all-season roads, and small local roads, in each ecozone.
Trails are not included because existing data sets are incomplete and unreliable. Seismic lines are not included in this indicator as they are considered temporary disturbances, which are tracked using another indicator. Future reports will provide information on non-linear features as it becomes available.
The information is obtained from national data sets produced by Natural Resources Canada: CanVec vector digital data7 for transmission lines and National Road Network vector digital data for roads8. The Enbridge pipeline vector digital data is obtained from the NWT Centre for Geomatics, Department of Industry Trade and Investment, Government of the NWT.
NWT Focus
Source: Ecozones: Ecological Stratification Working Group modified as Ecozone Plus map, roads and transmission lines from Natural Resources Canada , and pipeline from NWT Centre for Geomatics, Department of Industry Trade and Investment, Government of the NWT.
The total length of semi-permanent linear features within an area provides information on the extent of fragmentation or disturbance to a landscape. Some wildlife species may alter their behavior based on openings in forest canopy or ground cover and linear features on the landscape may affect wildlife movements. Some animals, such as wood bison3,4, use linear features as transportation corridors. Other species, such as Woodland Caribou6,13,16, avoid the openings. Once an area is opened, there is increased chance that people will use the linear feature as a new access point into previously inaccessible areas, increasing human presence for hunting and recreation. Linear features also represent removal of forest cover, which affects carbon storage and may affect sedimentation in water streams due to increased erosion16.
Current view: status and trend
The average road density in the NWT, including all-season roads, is very small at 0.22 km/100 km2. The Taiga Plains ecozone, which contains most of the NWT communities, has a slightly higher road density (0.5 km/100 km2). If all semi-permanent linear features are included, the average density for the NWT is 0.4 km/km2. The following table presents length and density of all semi-permanent linear features by each Ecozone. This information is considered baseline for year 2007. Changes in density of roads and other linear features can be tracked against these values in the future.
Source: Ecozones: Ecological Stratification Working Group9 modified as Ecozone Plus map10, roads and transmission lines from Natural Resources Canada7,8, and pipeline from NWT Centre for Geomatics, Department of Industry Trade and Investment, Government of the NWT.
Looking forward
New infrastructure and transportation corridors are established whendevelopment increases. As a result, linear disturbance is expected to increase on the landscape, and the effects of these changes on wildlife and other ecosystem components will be monitored.
Looking around
The extent of linear disturbance in the NWT (less than 1 km/100km2) is much less than in other areas in Canada. For example, road density in the BC portion11 of the Taiga Plains is 52 km/100km2. The average road density in Alaska is 1.5 km/100km2.
Find more
For more information on road densities in Canada, go to the Atlas of Canada, by Natural Resources Canada, at http://atlas.nrcan.gc.ca/site/english/index.html15.
Other focal points
For more information on natural changes in NWT Landscapes, go to the VEGETATION Focal Point. For more information on human activities themselves, some of which result in landscape changes, go to HUMAN ACTIVITIES.
Technical Notes
Road Density: Alaska has one mile of road for every 42 square miles of land area.
Updated: 16 May 2011
8.2 Seismic line density
This indicator measures seismic line density, in km/km2, in each terrestrial ecoregion of the NWT.
Data for this indicator is obtained from the National Energy Board (NEB). The version of this data used is dated June 2010. There is a five-year lag in the data that is included. Seismic line data goes back to 1958.
This indicator was reported as Fragmentation Density in 2010 and moved back to seismic line density in 2011. The information and data on fragmentation was used and retained in the new indicator on woodland caribou (see Focal Point SPECIES AT RISK).
NWT Focus
Seismic lines are the single largest landscape disturbance caused by humans in the NWT. In many parts of the NWT, they are the only indication of human disturbance in large areas of otherwise undisturbed forest land. In western Canada, seismic line and road density estimates are used as an indicator of habitat fragmentation for some forest-dwelling species. Fragmented habitat results in less use by some species. For example, studies in Alberta indicate that Woodland caribou occurrence decreases with increasing seismic line density. Assessments of caribou movement strongly suggest they prefer to be at least 100 meters away from seismic lines. There is also evidence to suggest that caribou in close proximity to seismic lines are at higher risk of being killed by wolves
Current view: status and trend
An unknown number of additional seismic lines were created in the NWT between June 2005 and today. As well, an unknown proportion of the old seismic lines included in the data set used for this indicator may have re-grown and may not be as visible on the landscape. By comparing the NEB data set of pre-1999 lines with maps of visible seismic lines obtained from satellite images for the Dehcho, it was found that the NEB data is incomplete. As a result, the density estimates presented in this report should be considered as minimum baseline numbers.
The Mackenzie Delta and Richards Island Coastal Plain in the Southern Arctic Ecozone have the highest seismic line densities at 6 km/km2 and 2.38 km/km2 respectively. Other areas of high seismic impact are the Liard Valley and Cameron Hills.
Map 1. Actual seismic lines from 1958 to approximately 2005. Source NEB. Densities of seismic lines in the Beaufort Sea were not calculated for this indicator, but are included in this map for completeness.
Map 2. Density of seismic lines in the NWT calculated for each Level 4 Ecoregion. Source NEB.
Looking forward
The density of seismic lines presented here only reflects seismic lines created up to 2005, and therefore the density figures are already dated. 2D and 3D seismic line programs were carried out between 2005 and 2011, although activity has been slower than previous years. Available details for these recent seismic programs can be found in the HUMAN ACTIVITIES focal point.
This indicator will continue to track changes in seismic line “footprint” using the information provided by oil-gas companies to the National Energy Board. The actual effects of increasing seismic line densities on wildlife and other components of NWT ecosystems are being studied and will be reported in this indicator in the future2,12,14.
Looking around
Some land use plans1 contain mechanism to look at seismic line density and how it affects boreal caribou. For more information on land use planning, go to PROTECTED AREAS AND LAND USE PLANNING focal point. How to quantify and use information about seismic line density is being explored by other jurisdictions, including Alberta.
Find More
For more information on the National Energy Board, go to http://www.neb.gc.ca/.
For more information on the Dehcho Land Use Plan and visible seismic lines obtained from satellite images for the Dehcho, go to http://www.dehcholands.org/home.htm
Technical Notes
Level 4 ecoregions are a sub-division of ecozone (Level 2 Ecoregions). Each level 4 ecoregion is considered unique in its combination of climate, geomorphology, geology, and ecosystem component. For more information on the new Ecosystem Classification of the NWT go to http://www.enr.gov.nt.ca/_live/wpPages/Ecosystem_Classification.aspx.
Updated: 21 July 2011
8.3 Area of commercial harvest
This indicator tracks the area harvested commercially for timber each year in the NWT. The information is obtained from all available records of timber cutting permits and licenses issued from 1975 to present by Forest Management, Government of the Northwest Territories
Volume of local fuel wood use is estimated at 20,000 to 30,000 m3per year and is not included in this indicator. Fuel wood includes live and dead wood harvested from all species.
NWT Focus
Commercial harvesting represents direct use of forest fibrefor local and export purposes. Timber harvesting is one of the few local resource-based opportunities in the NWT and represents a significant opportunity for sustainable local economy.
Current view: status and trend
Commercial timber harvesting has occurred in many places in the NWT, usually in localized areas and in small volumes. Typical commercial harvest operations are small-scale local businesses harvesting volumes of 500 m3 to 10,000 m3 of wood per year. The total area harvested per year is presented in the following table and graph, from 1975 to present.
Prior to 1993, area harvested was primarily measured based on a planned harvest, and not assessed using post-harvest footprint. After 1993, post-harvest footprints were part of the assessment of area harvested. Between 2000 and 2002 there was almost no commercial harvest, and only one small scale harvester.
Looking forward
Small scale commercial timber harvesting for saw logs and fuel wood will continue to occur at a local level. Almost all of the building lumber used in the NWT is shipped from southern brokers bu there is a small amount of lumber produced for local uses in several comunities.
The GNWT has implemented a biomass strategy to encourage the use of wood and wood products as an economical and ‘green’ energy source, and to reduce reliance on fossil fuels. The government is actively converting government buildings to pellet boilers, which has driven the demand for wood pellets up. There are also recent developments identifying values associated with home heating from “green” sources, such as fuelwood, wood pellets, or ethanol, which will have an impact on trends in commercial harvesting. Given recent increases in fuel prices, more people may be looking toward using wood as a source of fuel. This may increase commercial harvesting for fuel wood or other forms of biomass energy. Increasing transportation costs may also drive more demand for local wood products.
The GNWT is actively collecting baseline information on the state of the forest resources and developing better tracking mechanisms to track and manage forest harvesting.
Look around
The total area harvested for commercial timber in Yukon (2007) was 12 ha, in Alberta (2007) 54,981 ha, in British Columbia 197,599 ha (5).
Find out more
Other focal points
For more information on other forest indictors in the VEGETATION focal point.
Updated: 9 May 2011
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Reference List
Ref 1 - 2008. Dehcho Land Use Planning Committee
Ref 2 - Ashenhurst, A. R. and S. J. Hannon. 2008. Effects of seismic lines on the abundance of breeding birds in the Kendall Island Bird Sanctuary, Northwest Territories, Canada, Arctic, 61:190- 198
Ref 3 - Brodie, J. F. 2008. A review of American bison (Bos bison) demography and population dynamics. Wildlife Conservation Society & Pennsylvania State University.
Ref 4 - C.Cormack Gates, J. Mitchell, J. Wierzchowski, and L. Giles. 2001. A landscape evaluation of bison movements and distribution in Northern Canada. AXYS Environmental Consulting Ltd., Calgary.
Ref 5 - Canadian Forest Service. 2008. Canada's Forest - Statistical Data. Government of Canada.
Ref 6 - S. J. Dyer, J. P. O'Neill, S. M. Wasel, and S. Boutin. 2002. Quantifying barrier effects of roads and seismic lines on movements of female woodland caribou in northeastern Alberta. Can.J.Zool. 80:839- 845.
Ref 7 - Earth Sciences Sector, M.S.B.C.T.I. 2007. CanVec vector digital data. Sherbrooke, Natural Resources Canada, Government of Canada.
Ref 8 - Earth Sciences Sector, M.S.B.C.T.I. 2007. National Road Network vector digital data. Sherbrooke, Natural Resources Canada, Government of Canada.
Ref 9 - Ecological Stratification Working Group. 1996. A national ecological framework for Canada. Ottawa, Agriculture and Agri-Food Canada. Research Branch, Center for Land and Biological Resources Research and Environment Canada. State of the Environment Directorate, Ecozone Analysis Branch.
Ref 10 - GNWT ENR. 2008. NWT Ecozone Plus. 2008. Yellowknife GNWT.
Ref 11 - Government of British Columbia. 2007. Environmental Trends in British Columbia 2007 - Ecosystems, Government of Columbia.
Ref 12 - A. Gunn, et. al. 2004. Boreal caribou habitat and land use planning in the Dehcho region, Northwest Territories.Government of the Northwest Territories.
Ref 13 - A. R. C. James, and A. K. Stuart-Smith. 2000. Distribution of caribou and wolves in relation to linear corridors. Journal of Wildlife Management 64:154- 159.
Ref 14 - C. S. Machtans. 2006. Songbird response to seismic lines in the western boreal forest: a manipulative experiment. Can.J.Zool. 84:1421- 1430.
Ref 15 - Natural Resources Canada. 2004. The Atlas of Canada - Road Density. Natural Resources Canada.
Ref 16 - Peggy Holroyd. 2008. University of Calgary.
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