Bell Canyon Mountain Mahogany Planting

Story and photos by Katie Benzel, Wildlife Biologist, Dillon Field Office

Curl-leaf mountain mahogany (Cercocarpus ledifolius) is a deciduous shrub that is an important big game browse species. It is especially preferred by mule deer, moose and elk during the winter. Across southwest Montana it receives

heavy browse pressure and is being shaded out by juniper and Douglas fir.

Managing for both retention of mountain mahogany habitat and big game winter range is complicated. If mahogany is fenced off to protect it, an important dietary component for big game is eliminated. The Dillon Field Office does have a couple of mahogany exclosures.

It has been hypothesized that long-term declines in mule deer populations in this area may be due to a reduced carrying capacity from decreased browse availability. In an attempt to reverse these trends, Montana Fish, Wildlife and Parks has implemented an either sex mule deer hunting structure aimed at maintaining existing populations within modern carrying capacity.

Increasing forage and browse for mule deer is also a component to achieving this. At several sites, the DFO has mechanically removed juniper and Douglas fir that is expanding into mahogany habitat, leaving it as a browse barrier to protect the shrubs, and continues to identify areas for future treatment.

As another option for maintaining mountain mahogany, the DFO planted seedlings at two sites. Although the DFO had never planted mountain mahogany before, they decided to give it a try with 700 seedlings that were propagated at the Forest Service Couer d’Alene Nursery.

Bell Canyon was picked for one of the planting sites because there has been a noticeable increase in dead mountain mahogany for several years, the result of heavy browsing by big game. Mountain mahogany typically grows on very rocky sites, so planting was not easy and required spud bars to dig holes deep enough for the 6-inch roots. Bell Canyon is also rattlesnake country and workers encountered three while planting.

Juniper expansion into the Bell Canyon mahogany habitat is a concern, so as part of the planting project, some of the juniper was cut down with chain saws and used as a browse barrier for the planted seedlings. Bio-degradable browse tubes with bamboo stakes were also tested out.

Despite the difficult planting conditions, 19 permanent and seasonal DFO staff, as well as two Butte FO seasonal employees, worked incredibly hard to plant and protect 400 seedlings on May 15. Their hard work and positive attitudes were essential to planting the hundreds of seedlings. The willingness of employees to help each other out is not only required to complete projects, but it also builds office morale and working relationships.

The other 300 seedlings were planted near the Madison River, just north of Bear Trap Canyon, at a mountain mahogany site that had been burned by wildfire. Considering the heavy browse pressure that mountain mahogany endures, these seedlings have a challenge for survival ahead of them. The DFO will continue to have the challenge of how to retain mountain mahogany on the landscape.