6. Pressures - Landscape Changes

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Introduction
6.1 Status of Landscape Disturbance by Ecozone
6.2. Area of Commercial Forest Harvest

Introduction

Human activities can result in changes to landscape features that are present 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 wildlife use and movement patterns.

Permanent features are expected to remain noticeable on the landscape into the foreseeable future, although they could be reclaimed when no longer needed. This category includes roads, communities, and large mine sites.

Semi-permanent features are usually those that are maintained by humans on the landscape. This category includes power transmission lines, pipelines, well sites, small to medium camps, 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. This category includes seismic lines and commercial forest harvesting areas. Depending on the landscape impacted, some areas return to a non-noticeable state relatively quickly, while some remain noticeable for a longer period of time.

Compared to jurisdictions in southern Canada, human-caused landscape changes in the Northwest Territories (NWT) are relatively small, but still measurable. As more infrastructure and renewable and non-renewable resources are developed in the NWT, management agencies are increasing the capacity to monitor the size and cumulative impacts of landscape changes. Many organizations, including all levels of government, Indigenous governments, Indigenous organizations, renewable resource and regulatory boards, and industry are working together to develop coordinated mechanisms for tracking and reporting on landscape changes. Landscape changes resulting from climate and wildfires are found in other focal points, such as Climate and Weather, Vegetation, and Permafrost.

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6.1 Status of Landscape Disturbance by Ecozone

This indicator measures landscape disturbance due to human activities, which includes footprints of linear features (i.e., roads, seismic lines, power transmission lines and pipeline right-of-ways) and non-linear features (i.e., communities, commercial development and resource exploration and extraction activities). Changes to the landscape resulting from indirect effects of human activity or natural processes, such as erosion, permafrost thaw or wildfires, are not included in this indicator. Managing our environment effectively requires an understanding of current pressures, including the impact of landscape disturbances.

Linear and non-linear landscape disturbance in the NWT © GNWT

This indicator was prepared by the Government of The Northwest Territories, Department of Environment and Climate Change with support from a contractor, using disturbance datasets supplied by NWT Centre for Geomatics (NWTCG). See the Technical Notes section for details on the datasets and methods used for this indicator.

NWT Focus

Human-caused landscape disturbances have an impact on vegetation, wildlife populations and their habitat, and predator-prey interactions (Ref. 1, 2, 3). Wildlife species often alter their behaviour based on changes to and openings in forest canopy or ground cover. For example, wood bison (Ref. 4, 5) and wolves (Ref. 6) use linear features as transportation corridors, while other species, such as woodland caribou (both boreal caribou and northern mountain caribou; Ref. 7, 8) avoid linear features due to a higher risk of predation. Boreal caribou range planning is currently underway across the species range in the NWT to protect critical habitat, which is defined as at least 65% undisturbed habitat. Once an area is opened by a linear feature, there is a higher probability of humans using this feature as a new access point and entering previously inaccessible areas, which can increase human presence for purposes such as hunting and recreation. At the same time, the presence of landscape disturbances may also reduce the usability of the land by harvesters due to reduced availability of certain species (Ref. 3).

Current View: status and trend

As of the end of 2020, less than 0.1% of the NWT landscape has been disturbed by human activities. However, approximately two thirds (481 km2) of the disturbances were the result of linear developments, which play a key role in fragmenting wildlife habitat. These measures from 2020 will be used as a baseline information for future updates of this indicator, in order to calculate trends in landscape disturbance over time.

The Taiga Plains is the most impacted ecozone, with the percentage of disturbance twice the NWT average. In comparison, the Northern Arctic sees only a fraction of the development located in other regions. Linear features make up the majority of disturbed area across the NWT, with the highest percentage occurring in the Taiga Plains.

Table 1 – Amount and percentage of landscape disturbance due to linear features within each NWT ecozone.

	Linear Features
Ecozone	Disturbed Area (km2)	% Disturbed
Boreal Cordillera	13.1	0.023%
Northern Arctic	0.9	0.000%
Southern Arctic	13.1	0.008%
Taiga Cordillera	32.3	0.033%
Taiga Plains	545.9	0.116%
Taiga Shield	30.5	0.009%
Tundra Cordillera	5.4	0.068%
NWT Totals	641.1	0.048%

Table 2 – Amount and percentage of landscape disturbance due to non-linear features within each NWT ecozone.

	Non-Linear Features
Ecozone	Disturbed Area (km2)	% Disturbed
Boreal Cordillera	7.2	0.013%
Northern Arctic	4.7	0.002%
Southern Arctic	79.0	0.047%
Taiga Cordillera	2.0	0.002%
Taiga Plains	204.6	0.044%
Taiga Shield	73.7	0.023%
Tundra Cordillera	1.5	0.020%
NWT Totals	372.8	0.028%

Table 3 – Amount and percentage of landscape disturbance due to both linear and non-linear features within each NWT ecozone.

	Combined Features
Ecozone	Disturbed Area (km2)	% Disturbed
Boreal Cordillera	20.3	0.036%
Northern Arctic	5.6	0.003%
Southern Arctic	92.1	0.055%
Taiga Cordillera	34.3	0.035%
Taiga Plains	750.5	0.160%
Taiga Shield	104.2	0.032%
Tundra Cordillera	6.9	0.087%
NWT Totals	1,013.9	0.076%

Figure 1. Maps show land disturbances in each ecozone in the NWT. Credit: GNWT

Looking forward

The datasets included in the analysis of this indicator are updated annually. This will allow trends to be calculated using the same approach in future updates of this Indicator. Trends in landscape disturbance will be impacted by any additional human activities, such as new infrastructure and transportation corridors, as well as reductions to the size of some current disturbances as re-vegetation occurs, such as old seismic lines. The rate of revegetation of disturbed areas will vary greatly by location and depend on growing conditions.

Find out more

Comprehensive maps of human and natural disturbance for the NWT, such as roads and wildfires are available online through the Inventory of Landscape Change (ILC) Web Viewer at www.nwtcimp.ca (Ref. 11). This web viewer is a powerful tool that can be used to explore cumulative impacts by layering disturbance maps. The human disturbance layers on the ILC are updated annually and are available for download.

Other focal points

For more information on natural changes in NWT Landscapes, go to Section 14 Vegetation.
For more information on human activities, some of which result in landscape changes, go to Section 5 Human Activities.

Technical Notes

Landscape disturbance was defined using datasets from a series of map layers from three primary sources that are maintained by the NWTCG:

Natural Resources Canada: CanVec digital datasets (Ref. 9) include the National Road Network, trails, seismic lines, airstrips, and hydro power facilities;
NWT Centre for Geomatics (NWTCG): updates map layers (Ref. 10) including pipeline right-of-ways, fibre optic and power transmission lines;
NWT Cumulative Impact Monitoring Program (NWT CIMP): provides a series of datasets managed through the Inventory of Landscape Change initiative (Ref. 11). These map layers are updated annually through a review of land development permits and current satellite images. The NWT CIMP datasets include a series of miscellaneous disturbance features that include community footprints and various other features that have not been mapped in any of the above-mentioned map layers.

This combination of map layers minimizes missing features, and each layer has been combined to eliminate any overlapping features from the data sources.

Linear features form a significant portion of the disturbed landscape. They can be buffered using GIS to provide a realistic areal extent of disturbance. The following datasets and widths were used:

Linear dataset sources managed by NWTCG:

Theme	NWTCG Data Source	Feature Width
Roads	sd_DBO_TRA_NRCAN_NRN_Roadsegment	15m per lane
Railways	sd_DBO_TRA_NRCAN_NTDB50K_Railways	15m
Power transmission	sd_DBO_Trans_GNWT_prj	15m
Fibre optic transmission	sd_DBO_UTC_NWTEL_FibreOptic_Lines	15m
Pipelines	sd_DBO_STR_NWTCG_NWTAreaPipelines	30m
Hydroelectric dams	sd_DBO_STR_NRCAN_CanVec_ManmadeHydroObs	40m
Seismic cut lines	sd_DBO_TRA_NRCAN_NTDB50K_Cutlines	2.5m
Trails	sd_DBO_TRA_NRCAN_NTDB50K_Trails	2.5m
Land and Water Board permitted developments	sd_DBO_HumanDevelopmentFootprint_Lines (NWT CIMP)	Various*
Other visible land disturbances	sd_DBO_UnvalidatedHumanDevelopmentData_Lines (NWT CIMP)	Various*

* Widths are applied based on the Disturbance Type attributes in the datasets. A large number of features do not have an assigned Disturbance Type and are often seismic cut lines and assigned a width of 2.5m.

Polygons are captured to map the true extent of non-linear land disturbances. These features can be used directly in land disturbance calculations. The following polygonal datasets were used:

Polygonal dataset sources managed by NWTCG:

Theme	NWTCG Data Source
Airstrips / Runways	sd_DBO_TRA_NRCAN_CanVec_Runways
Land and Water Board permitted developments	sd_DBO_HumanDevelopmentFootprint_Areas (NWT CIMP)
Other visible land disturbances	sd_DBO_UnvalidatedHumanDevelopmentData_Areas (NWT CIMP)

Some smaller features are often mapped as points, typically for mining exploration purposes. In these cases, the features are buffered to form a more accurate spatial extent. Overall, these point features make up a small portion of the land disturbance.

Point dataset sources managed by NWTCG:

Theme	NWTCG Data Source	Feature Area
Telecommunication Facilities	sd_DBO_UTC_NWTEL_TeleCommunications_Infrastructure	20m buffer
Hydroelectric Facilities	sd_DBO_HydroFacilites_prj	20m buffer
Land and Water Boards permitted developments	sd_DBO_HumanDevelopmentFootprint_Points (NWT CIMP)	Various*

* Land and Water Boards point datasets have an attribute that denotes the feature area based on documentation in the permit registry. These areas are used to calculate a buffer that best approximates the areal extent of each individual feature.

Linear features above have been buffered, merged and dissolved to remove overlapping areas that would result in double counting of area metrics. Buffered point features were merged with each polygonal dataset. Features derived from sd_DBO_UnvalidatedHumanDevelopmentData_Areas were only selected when features were not assessed to be reclaimed with no significant visible disturbance using the Definition Query “PostActivityDisturb IN (NULL, '1', '3', '4')”; Class 2 indicates features that have been reclaimed to a more natural state.

All features were dissolved to remove overlaps and then combined with linear features to maintain attributes to discern linear and non-linear data sources. Linear features often overlap polygonal features (such as roads in a community). In these cases, the linear features were removed and superseded by the polygonal features. In most cases, winter roads are attributed as such. Other winter roads were selected from the National Road Network and the NWT CIMP Human Development Lines where they regularly travelled along lakes. These winter roads were selected, unioned with NTDB 1:50,000 scale lakes, and areas over water were removed from the dataset, leaving only the portion travelled over land.

The combined linear and non-linear features were then unioned with ecozones (i.e., Level II EcoRegions sourced from sd_DBO_BIO_ENR_FMD_NWT_EcoRegions) to facilitate tabulation of areas per ecozone for buffered linear and non-linear features.

The land disturbance indicator assessment has been completed by NWT CIMP with assistance from Caslys Consulting Ltd. using the current (March 2021) disturbance datasets that have been supplied by NWTCG.

References

Ref. 1. Johnson, C.J., M.S. Boyce, R.L. Case, H.D. Cluff, R.J. Gau, A. Gunn, and R. Mulders. 2005. Cumulative Effects of Human Developments on Arctic Wildlife. Wildlife Monographs 160: 4-31. (https://wildlife.onlinelibrary.wiley.com/doi/abs/10.2193/0084-0173(2005)160[1:CEOHDO]2.0.CO;2)

Ref. 2. Gunn, A., C. J. Johnson, J. S. Nishi, C. J. Daniel, D. E. Russell, M. Carlson, and J. Z. Adamczewski. 2011. Understanding the Cumulative Effects of Human Activities on Barren-Ground Caribou. in P. R. Krausman and L. K. Harris, editors. Cumulative effects in wildlife management: impact mitigation. CRC.

Ref. 3. Tyson, W. 2015. Assessing the cumulative effects of environmental change on wildlife harvesting areas in the Inuvialuit Settlement Region through spatial analysis and community based research. MSc thesis, School of Environmental Studies, University of Victoria, Victoria, British Columbia (http://dspace.library.uvic.ca/bitstream/handle/1828/6927/Tyson_William_MSc_2015.pdf?sequence=1&isAllowed=y)

Ref. 4. Brodie, J.F. 2008. A review of American bison (Bos bison) demography and population dynamics. Wildlife Conservation Society and Pennsylvania State University.

Ref. 5. Corman Gates, C., J. Mitchell, J. Wierzchowski, and L. Giles. 2001. A landscape evaluation of bison movements and distribution in northern Canada. AXYZ Environmental Consulting Ltd. Calgary, AB.

Ref. 6. Dickie, M., Serrouya, R., McNay, R. S., and S. Boutin. 2017. Faster and farther: wolf movement on linear features and their implications for hunting behaviour. Journal of Applied Ecology, 54(1): 253-263.

Ref. 7. Dyer, S.J., 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. 8. James, A.R.C., and A.K. Stuart-Smith. 2000. Distribution of caribou and wolves in relation to linear corridors. Journal of Wildlife Management 64:154-159.

Ref. 9. Natural Resources Canada. 2020. CanVec data compiled from National Topographic Data Base and GeoBase datasets, Natural Resources Canada. (https://atlas.nrcan.gc.ca/toporama/en/index.html)

Ref. 10. NWT Centre for Geomatics. 2020. NWT Centre for Geomatics Spatial Data Warehouse - Spatial Data Engine (SDE) Department of Finance, Government of Northwest Territories. (https://www.geomatics.gov.nt.ca/en/services/geomatics-services)

Ref. 11. NWT Cumulative Impact Monitoring Program. 2020. Inventory of Landscape Change Webviewer, NWT Cumulative Impact Monitoring Program, Department of Environment and Climate Change, Government of Northwest Territories. (https://www.ecc.gov.nt.ca/en/services/nwt-cumulative-impact-monitoring-program-nwt-cimp/finding-data-and-information)

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6.2. Area of Commercial Forest Harvest

This indicator tracks the area harvested commercially for timber each year in the NWT. Timber harvest areas are considered to be temporary features on the landscape that regenerate naturally over time and are monitored for regeneration success.

The volume of fuel wood harvested under free timber cutting permits for personal use is estimated to be 20,000 to 30,000 m3 per year and is not included in this indicator. Fuel wood includes live and dead wood harvested from all timber species.

This indicator was prepared by the Government of the Northwest Territories, Department of Environment and Climate Change, using information obtained from all available records of timber cutting permits and licenses issued from 1975 to 2019 by the Forest Management Division.