Forest Investment Account (FIA) - Forest Science Program
FIA Project Y091159

    Effects of a Mountain Pine Beetle epidemic on Northern Caribou habitat use, migration and population status
 
Project lead: Cichowski, Deborah (Bulkley Valley Centre for Natural Resources Research and Management)
Author: Cichowski, Deborah B.
Subject: Forest Investment Account (FIA), British Columbia
Series: Forest Investment Account (FIA) - Forest Science Program
Description:
The Tweedsmuir-Entiako caribou population summers in the North Tweedsmuir Park area, and winters in the Entiako and East Ootsa areas. During winter, caribou select mature lodgepole pine forests where terrestrial lichens are abundant, and forage primarily by cratering through the snow to obtain terrestrial lichens. The Committee on the Status of Endangered Wildlife in Canada (COSEWIC) has recently listed all caribou in the Southern Mountains National Ecological Area (SMNEA), which includes the Tweedsmuir-Entiako population, as Threatened. The Recovery Strategy for Northern Caribou in the SMNEA in BC identifies research on the effects of mountain pine beetles on Northern Caribou as a priority. One of the greatest threats currently facing most Northern Caribou populations in BC and Alberta is the impact of the extensive mountain pine beetle outbreak. Since this scale of mountain pine beetle attack has been unprecedented on
caribou ranges in recent history, there is no information available on the effects of mountain pine beetles on caribou, making it difficult to develop management prescriptions that minimize impacts to caribou. The Tweedsmuir-Entiako caribou population is the first caribou population to experience the current mountain pine beetle epidemic. All Northern Caribou populations in BC and Alberta are at risk of experiencing the mountain pine beetle epidemic due to climate change and a northerly expansion of mountain pine beetle distribution. Therefore, information collected on the Tweedsmuir-Entiako population will benefit all Northern Caribou populations.

The current mountain pine beetle epidemic was detected in the East Ootsa and North Tweedsmuir Park areas in the mid 1990’s. By the late 1990’s, mountain pine beetle numbers reached epidemic levels on both summer and winter ranges. By 2007, most mature lodgepole pine stands in the
Tweedsmuir-Entiako caribou winter range have been attacked by mountain pine beetles and are in the “grey attack” phase of the epidemic.

Three of the most critical questions that need to be answered regarding effects of mountain pine beetles on caribou are:
• How will caribou winter habitat be affected by mountain pine beetle attack? (i.e. how will terrestrial lichens respond? will snow accumulation increase due to a loss of canopy and/or will eventual blowdown lead to impeded movements?)
• How will caribou habitat use and winter range use be affected by extensive mountain pine beetle attack? (i.e. will caribou avoid using mountain pine beetle-attacked habitats for traveling or foraging during winter and migration and/or will they alter foraging strategies in beetle killed areas?)
• How will caribou population dynamics be affected by extensive mountain pine beetle attack? (i.e. will mortality rates and causes, and/or population growth change following the mountain pine beetle epidemic).

In 2001, a project was initiated in the East Ootsa and Entiako areas to monitor the response of terrestrial lichens to mountain pine beetle attack and forest harvesting, and to monitor changes in coarse woody debris as an indicator of movement barriers. Preliminary data from 2003 and 2005 suggest that kinnikinnick is proliferating on some sites and affecting terrestrial lichen abundance. However, until fieldwork for this project was initiated in 2006/07, no information had been collected on how caribou habitat use is changing in response to mountain pine beetle disturbance or whether population dynamics have been affected. Mountain pine beetle disturbance could presumably start affecting caribou habitat use now that areas are advancing from red attack to grey attack (i.e. trees that have lost their dead needles) with a corresponding change in snow interception. It is important to examine both changes in caribou habitat and changes in caribou habitat use and population dynamics to determine the overall impacts of mountain pine beetles on caribou.

The purpose of this project is to address the second question - How will caribou habitat use and winter range use be affected by extensive mountain pine beetle attack? Caribou select habitat at different spatial scales and therefore will likely respond to disturbances on different spatial scales. At the landscape scale, caribou may avoid large areas within their ranges if large-scale disturbances or increased human activity occurs. Also at the landscape level, caribou occasionally shift their range use patterns, presumably to avoid overgrazing of lichens. Therefore, large-scale disturbances such as this mountain pine beetle epidemic could affect their ability to shift ranges. At the stand level, caribou may continue using individual stands affected by disturbance if they are interspersed within undisturbed areas. For example, caribou may continue to use mountain pine beetle killed stands if they are able to travel to them in unaffected stands. That is, they may tolerate barriers to movement within the stands that they forage in if sufficient movement is possible in adjacent stands.

In addition, the population currently appears to be declining and therefore winter range use patterns need to be addressed in the context of a declining population. Since recovery planning needs to address both critical (current) and recovery habitat, the ability of caribou to use beetle-attacked winter range will be an important consideration for the recovery group when determining the amount and configuration of recovery habitat required compared to what is currently available.

This project “Effects of a Mountain Pine Beetle epidemic on Northern Caribou habitat use, migration and population status” was initiated in 2005/06 with funding from Ministry of Environment, Morice Lakes Innovative Forest Practices Agreement (IFPA) and Houston Forest Products. In 2006/07, monthly radio-telemetry flights were conducted funded by FIA-FSP MPB funding (Project M07-5047), and other activities were funded by Ministry of Environment and the Morice Lakes IFPA. FIA-FSP MPB funding has continued for 2007/08 for monthly radio-telemetry flights through Project M08-6047. Other activities in 2007/08 are being funded by Ministry of Environment, Mountain Pine Beetle Response funding, the Morice Lakes IFPA, and Habitat Conservation Trust Fund. Additional funding is required to carry out all aspects of the project until project completion in 2009/10. The Ministry of Environment has been tracking radio-collared caribou in the Tweedsmuir-Entiako area for 20 years, resulting in a large pre-mountain pine beetle attack database. Preliminary information from this project from 2006/07 suggests that caribou habitat use and winter foraging strategies in grey mountain pine beetle attack are similar to strategies prior to mountain pine beetle attack. Data collection is currently being conducted in 2007/08 and is planned for 2008/09.

Another similar project (Response of woodland caribou to partial retention logging of woodland caribou ranges attacked by mountain pine beetle; FSP M07-5049) is being conducted on the Kennedy-Siding caribou population. The two projects are complimentary since this project focuses on caribou habitat use during the “grey” phase of the mountain pine beetle epidemic, while the Kennedy-Siding caribou project focuses on caribou habitat use during the “green” and “red” attack phases of the epidemic and also investigates the effects of mountain pine beetle management/salvage logging.
Related projects:  FSP_Y102159

    Deliverables:

Annual summary report (1.6Mb)

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Updated August 16, 2010 

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