Impacts of Pine Beetle Harvesting on Mule Deer Winter Range in the Merritt TSA


The mountain pine beetle has always been part of BC’s ecosystem, with a co-existence between lodgepole pine and beetle. However, over the past few years mountain pine beetle has reached an epidemic level for the are. Following this, there is a surge to recover as much merchantable timber as possible. With the urge to harvest merchantable timber, economic pressure is high for the quality of standing dead timber. It is then important to also manage to protect the landscape at the same time. With this perspective in mind, in 2005 the Provincial Chief Forester settled an allowable annual cut of 2 million m3 in the Merritt Timber Supply Area, located in the southwest interior BC, including around 1 million m3 to deal with the mountain pine beetle spreading. Although, there is a big population of douglas-fir (47%) in the designated biogeoclimatic zone, and it considered to provide the most suitable mule deer winter range habitat. This is why the Lower Nicola Indian Band (LNIB) presented concern over the impact that this harvest would have on the wintering mule deer. Therefore, a project was submitted to monitor the reactions and behavior of the mule deer towards the MPB harvest.


For this project three areas were selected through a selection of track transect and coarse habitat sampling. They are Dry Lake, Dillard and Danish Lake, the last providing the opportunity to collect pre-harvest treatment data. In order to monitor deer activity snow track transects and pellet plot sampling analyses were taken. The samples and analyses, as well as the  monitoring have been taken place since 2007. As for the snow tracking sampling, the first one was done from December 21st to 23rd 2009, after a snow event, and the second one was completed in the later winter period from February 15th to 17th 2010.

HCTF, Weyerhaeuser and the Nicola Similkameen Innovative Forestry Society (NSIFS) contributed the funding of the project. NSIFS took part after 2009 at a reduced level, as HCTF could not continue anymore due to reductions in Forest Investment Account funding allocations.

The study of the snow tracking samples were not finished, and were planned for 2010-2011 as part of a five year summary report.

There are very few studies and information regarding the possible impact of MPB salvage on mule deer. Additionally, when there is harvesting happening in an area susceptible for mule deer winter range, the harvesting should follow legal obligations. However, wildlife measures are in process of the final stages but are management guidelines based  on research conducted in the Cariboo Forest Region. So there is the possibility that the guidelines may not apply directly to the dry ecosystems of the Southern Interior.The primary management endorsement has been determined to keep and protect forest coverage. Forest coverage intercepting the snow reduces energetic costs of moving through snow for the mule deer, and provides thermal and security cover. Furthermore, it is unknown how a reduction of snow coverage will impact on the mule deer, and there is a concern that areas of suitable forest  cover may become isolated by salvage activities.

Nevertheless, the Lower Nicola Indian Band (LNB) showed interest in studying the impact of the MPB salvage on wintering mule deer.

Objectives of the project

The project has two temporal interests, short and long-term objectives. The short objectives would be over the span of 1 to 3 years by monitoring impacts of MPB harvesting in the mule deer winter range areas. The study will attempt to identify critical habitat features utilized by deer with a probability of change due to the MPB harvesting. The study will also monitor impacts of increased road density in terms of disturbance, recreation and hunting pressure. And finally the study will incorporate findings into short-term MPB planning.

On the long-term, approximately 4 to 5 years, the objectives are to compare the use of deer winter range at different intervals in time, starting from early winter to late winter. This study will correlate deer use of habitat features in terms of snowpack and forage availability. Finally it will, provide findings to assist decision making surrounding mule deer winter range guidelines.


The study area for this project is vast. The Merritt TSA extends from Canada/USA border and Manning Park in the south to Logan Lake in the north. As said in the introduction is it covered in the majority of douglas-fir. Generally speaking the methods used are two harvest treatments with two controls, replicated over 3 study areas in order to properly select areas of suitable mule deer winter range.

Track transect sampling was taking during the winter period at different times and compared in order to cross perpendicular to the range of habitat from harvest.


Finally, from the track transect sampling two rounds of snow track were completed on schedule. However, the snow coverage was low with a mild winter in 2009-2010, and many of the tracks during that winter had to estimated by eye.  Moreover,  the low snowpack has reduced energy in the deer mobility, it might limit the growth of browse species. Concluding that the results for the next winter will appear and be analysed in the next summary report, as part of the five year project.

  • Source Lower Nicola Indian Band. March 2010. Impacts of Pine Beetle Harvesting on Mule Deer Winter Range in the Merritt TSA: Final Report – 2009-10. Prepared for Habitat Conservation Trust Fund and Nicola Similkameen Innovative Forestry Society. Available at : [Accessed 03/2021].