The Boreal Caribou Ecological Model

Developed by the Habitat Restoration Working Group (HRWG) of the National Boreal Caribou Knowledge Consortium (NBCKC).

Habitat restoration is expected to play a key role in the recovery of boreal woodland caribou (Rangifer tarandus caribou) in Canada. Population declines are correlated with the proportion of ranges affected by anthropogenic and natural disturbances and reversing these impacts is expected to benefit caribou populations. However, there are various mechanisms that lead from habitat stressors to caribou declines, and the effects of these mechanisms differ among ranges.

Understanding the ecological pathways driving observed relationships can inform restoration planning by:

1. directing treatments towards the most critical, range-specific mechanisms;
2. identifying possible confounding factors that need to be addressed; and,
3. supporting adaptive management by generating testable hypotheses and clarifying monitoring needs.

Here we present a conceptual Boreal Caribou Ecological Model developed by the Habitat Restoration Working Group of the National Boreal Caribou Knowledge Consortium. The model is composed of 14 factors and associated relationships that generate pathways leading from a variety of landscape disturbance stressors. The model does not capture all possible factors in the system, but only those that are likely exerting significant effects. Nor does it address specific restoration treatment options but it can inform the design of treatments by identifying the functional effects that treatments should be addressing.

Caribou survival and recruitment are affected directly by predation, nutrition, disease and hunting. All of these link back to one or more habitat stressors that drive the national disturbance model (i.e., fire, insect pests, forest alteration/clearing and linear development). The individual relationship pathways interact with each other and can also be affected by external factors. The habitat stressors alter forage available to caribou and to other primary prey, the distribution and abundance of primary prey, associated predators and of humans, and ultimately cause population declines via lower caribou survival and reproductive success.

A key next step for the conceptual model is the development of appropriate response metrics to monitor response to restoration efforts. This would provide the means to compare the relative effects of different drivers among ranges and would highlight key knowledge gaps. The model would then provide a complete framework for adaptive management as habitat restoration is implemented.

links to the Tools developed by the Habitat Restoration Working Group:

• The Boreal Caribou Ecological Model (current page)
  • Infographic
  • Technical Report
  • Boreal Caribou Habitat Restoration Practices: Applications and Outcomes (in prep)

To learn more about caribou habitat restoration please visit our 'Caribou Habitat Restoration' page [under development].

Project Description:

The primary scope of this project will be an assessment of historical, current, and predicted caribou ranges and space use in the province of Newfoundland and Labrador. This will include time-series analysis of habitat characteristics and connectivity in order to determine if there have been changes in use of land cover type and patterns of movement by caribou over the past 40 years and, if those changes can be linked to changes in cover type or land use. The project will also complete an assessment of habitat availability and connectivity under different climate change scenarios.

Project Outcomes or Intended Outcomes:

There are several general objectives of this project

1. Delineate and quantify areas of the landscape utilized by caribou in Newfoundland and Labrador.
2. Delineate and quantify landcover types found in areas utilized by caribou.
3. Delineate and quantify changes in landcover in areas utilized by caribou over time.
4. Where possible identify caribou range shift over time.
5. Determine the relationships between any observed caribou range shifts and any changes found in land cover types over time.
6. Compare/augment results with traditional knowledge data.
7. Determine potential impacts of climate change scenarios on caribou habitat availability and connectivity.
8. Generate information to support mitigation of road mortality through (i) analysis of movement patterns and space use relative to roads, (ii) selection of roads as a habitat feature, and (iii) generate a predictive map of relative risk along roads by comparing movement data and georeferenced data on road mortality compiled by the province and Parks Canada with factors such as road class (e.g. speed limit or road type) and surrounding habitat.
9. Mobilize project results and outputs so that they are available to, and usable by, a range of end-users.

Project DescriptionInvestigation into short-term and long-term progression of terrestrial forage lichen cover following wildfire in the Boreal Shield of northern Saskatchewan.

Project Outcomes or Intended OutcomesBased on forage lichen cover alone, we can conclude that Jack Pine stands as young as 21-30 years may provide a more suitable supply of forage cover for woodland caribou. Results explain how woodland caribou have persisted in an environment with high fire frequency and extent and that it may be more appropriate to include two phases of caribou habitat availability in models rather than applying a single threshold after which habitat is deemed suitable.

Project DescriptionMapping of fire from 1988-2013 using the differenced Normalized Burn Ratio analysis of Landsat Thematic mapper and Operational Land Imager.

Project Outcomes or Intended OutcomesFor some Boreal Shield ranges, including SK1, where fire comprises the majority of total disturbance and residual patches of unburned forest re abundant, total disturbance calculations, critical habitat designation and range planning decisions should take into account residuals, including water bodies.

Project Description:Despite decades of research assessing wildlife response to seismic lines, little is known about the effects of seismic line clearing on the quality of understory forage for wildlife, or about the resilience of boreal understory communities to seismic line clearing. Using field data collected from 351 seismic lines across west-central and north-western Alberta, Canada, and focusing on forage taxa preferred by moose and bears, we:

1. investigated whether understory forage taxa composition differed among seismic lines, seismic line edges, and the interior forest, and
2. assessed how this relationship changed as a function of seismic line attributes (ecosite, orientation, level of motorized human use, regeneration).
   
   In addition to help inform restoration efforts we:
3. used these field data and GIS derived and remote sensing (LiDAR) data to model and map vegetation recovery (growth, structure, and composition) on seismic lines and along seismic line edges.

Project Outcomes or Intended Outcomes:Generally disturbance-tolerant forbs and graminoids were more abundant on seismic lines, Rhododendron spp. and Vaccinium vitis-idaea were more abundant on edges, and Alnus, Salix and Betula spp. were more abundant on edges and seismic lines. Attributes of seismic lines did not explain patterns of understory forage abundance, although we found positive relationships between motorized human use and abundance of Chamerion spp. and non-target graminoids.

Using GIS data we found that wet seismic lines and seismic lines adjacent to open forest stands were more likely to have more early seral stage vegetation that is attractive wildlife forage. We also found that in west-central Alberta, wet seismic lines had less vegetation growth and cover, while in north-western Alberta, wet seismic lines were more likely to have more vegetation cover, but there was no relationship between vegetation growth on seismic lines and seismic line wetness. Our models of vegetation growth did not validate well other techniques (e.g. UAVs) and studies focused at smaller scales are likely to provide accurate data on current vegetation height and cover on seismic lines.

Our results combined with results from previous research provide further evidence that seismic lines, particularly wet seismic lines, need active restoration to re-establish natural vegetation trajectories. Overall, targeting seismic line restoration treatments to change vegetation composition, as well as structure and height, will likely help to restore ecosystem function for caribou and other boreal species.

Paper:
https://www.cclmportal.ca/resource/divergent-patterns-understory-forage-growth-after-seismic-line-exploration-implications

Project Description:
This report considers Tłı̨chǫ knowledge of the relationships that tǫdzı (boreal caribou) have with their habitat, including human and other-than human beings.

The current research grew from elders’ discussions at Ɂedèezhìi field camp about the importance of tǫdzı habitat around the Whatì area as the frequency and extent of forest fires continued to grow. The elders strongly suggested we pay more attention to tǫdzı winter habitat around Whatì and how they use islands in this area.

Project Outcomes or Intended Outcomes:
Final Report: Tǫdzı (boreal caribou) and the State of Their Habitat.
https://www.cclmportal.ca/resource/todzi-boreal-caribou-and-state-their-habitat

Principal Researcher: Allice Legat

Community Researchers: Camilla Nitsiza and Charlie J Nitsiza

Report Authors (see resource): Allice Legat and Mary McCreadie

Project Description:

ALCES models future changes based on known environment and landscape cover, an understanding of historic changes, and projected indicators of change to the environment, human footprint and landscape.

The project provides a forum to look at potential future outcomes of environmental changes to support decision-making in the Sahtu. Partnered with the Sahtu Environmental Research and Monitoring Forum, community members are helping define future scenarios of landscape change. These scenarios are then used to project simulations over the next 50 years. Simulations are being developed for climate and fire, population and settlements, energy and mining development, woodland caribou range disturbance and mountain caribou population dynamics.

Project Outcomes or Intended Outcomes:

Presentation available here:
https://www.cclmportal.ca/resource/sahtu-environmental-models-presentation

Sahtu Regional Environmental Decision Support Tool Set presentation:
https://www.cclmportal.ca/resource/sahtu-regional-environmental-decision-support-tool-set