2014 Inoculation of Whitebark Pine Seedlings with Native Ectomycorrhizal Fungi

Project:  Inoculation of Whitebark Pine Seedlings with Native Ectomycorrhizal Fungi

Agency/Forest or Park/District:  Montana State University (greenhouse study)

Project coordinator:  Dr. Cathy L. Cripps

Contact:  Dr. Cathy L. Cripps, Plant Sciences & Plant Pathology Dept., Montana State University, Bozeman, MT 59717, 406-994-5226, ccripps@montana.edu

Cooperators:  N/A

Source of funding/amount FHP:  $7,700 in WBP funding was received. Additional funding in the amount of $3,500 was provided by MSU for student salaries and horticultural supplies.  Not all funding has been used to-date as the project is continuing.

Dates of restoration efforts:

Objectives:  1) Develop a greenhouse study to examine how planting in soil from a burn affects the mycorrhizal status of whitebark pine seedlings previously inoculated with the native ectomycorrhizal fungus Suillus sibiricus, i.e., does the inoculated Suillus persist in burned soil and contribute to the survival of seedlings; 2) Conduct greenhouse bioassays to determine if ectomycorrhizal fungi are present in soils from beetle-killed, rust infested, or burned whitebark pine forests in the form of “viable spore banks”; 3) Stockpile slurries of ectomycorrhizal fungi for research and other restoration purposes.

Acres/ha treated:  N/A. Greenhouse study.


1) Approximately 150 whitebark pine seedlings were received from the Coeur d’Alene nursery and were pre-screened for mycorrhizal colonization. Seedlings were split into four treatment groups: i) inoculated and low N fertilizer, ii) inoculated and no fertilizer, iii) not inoculated and low N fertilizer, iv)  not inoculated and no fertilizer. Inoculation with the native ectomycorrhizal fungus Suillus sibiricus was performed on 9/30/13. Beginning 6/1/14 fertilizer was applied once every week. Two mycorrhizal assessments were performed over the next six months.

On 10/7/14 soil was collected from the Millie Fire Burn in the Gallatin National Forest. For the collection, two 50 m transects were established representing the overall burned stand. About ¾ gallon of soil was taken every 10 meters along each transect. Soil was taken to Montana State University and stored in a refrigerated room. The week of 10/22/14 all soil was sifted for rocks. Root material was replaced and soil from each transect was mixed half and half with lab perlite-soil mix. Soil was collected from the Millie Burn in Gallatin County and added to seedlings as they were transplanted into larger containers. Mycorrhizal assessment is ongoing for this experiment.

2) On September 20, 2014, 190 whitebark pine seedlings were received from the Coeur d’Alene nursery. The seedlings are watered to saturation 3 times a week and were fertilized with low N fertilizer twice in October. In October, 5 sites in the Gravelly Mountain Range, South Beaverhead-Deerlodge National Forest, were identified and visited for a soil collection. These site types ranged from declining WBP (beetles and/or rust) to regenerating healthy WBP, and one sagebrush dominated valley site. For the soil collections, two 50 m transects representing overall stand structure were established in each site. About a half-gallon of soil was taken every 10 meters along each transect, 8-12 in. into the ground, and was stored in an iced cooler. Soil was brought back to Montana State University and stored in a refrigerated room. Soil will be added to seedlings at transplanting and maintained in the greenhouse. These bioassays will help determine if viable suilloid fungi are present, or if inoculation of seedlings would be necessary if planting is to occur in these soils.

3) Fruiting bodies (mushrooms & truffles) of ectomycorrhizal fungi were collected in fall and made into slurries. These slurries are ‘stock-piled’ for our research and are available for other restoration purposes. They have already been used in several projects. Currently, the possibility of inoculating whitebark pine seedlings for a project where seedlings will be planted in a burned area in southwest Montana is under discussion. The ultimate goal of this research is to increase the survival rate of out-planted whitebark pine seedlings, particularly in areas devoid of ECM fungi.

Planting? If so, source of seedlings? Resistance?  Seedlings were obtained from the Coeur d’Alene Nursery and pre-screened for resistance.  We are very grateful to the Coeur d’Alene nursery for making seedlings available for this study.

Outcome:  Assessment of experiments is on-going.

Monitoring since completion of the project:


Plans for future monitoring?  We are hoping to be involved with a field trial using our inoculum starting in spring 2015 with monitoring at least in Fall of 2015, and hopefully 2016.

Will outcome meet goals?  Yes, the outcomes should meet the objectives and will lead to field

Future actions/follow up:  We still need to assess our greenhouse experiments. If a field study is implemented, it will be monitored as well.

Miscellaneous comments:  We are very grateful to the Coeur d’Alene nursery for making seedlings available for this study. Results will include information for protocols on the inoculation of whitebark pine seedlings with native ectomycorrhizal fungi in the greenhouse. Results will also include information on how inoculation and colonization proceeds in various native soils (with/without other fungi present). It can also tell us how ‘soil transfer’ might work as an alternative for inoculation and when/if inoculation is needed.

A new article on this research is just published online by American Forests at: http://www.americanforests.org/our-programs/endangered-western-forests/underground-connection-fungi-and-pines-in-peril/

Other research that was possible as a result of this grant is now published: Cripps, C. L., Lonergan, E., and C. Smith. 2014. Survival of whitebark pine seedlings inoculated with ectomycorrhizal fungi. Nutcracker notes 26: 15-18.  Lonergan Cripps 2014 whitebark inoculation year 3 nutcracker notes