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    Restoration of whitebark pine on a burn site utilizing native Ectomycorrhizal suilloid fungi
    (Montana State University - Bozeman, College of Agriculture, 2017) Jenkins, Martha Lee; Chairperson, Graduate Committee: Cathy L. Cripps
    The compilation of threats both natural and anthropogenic and the resulting loss of whitebark pine has led scientists and land managers to actively pursue a strategy for restoration of this keystone species. A range-wide strategy for restoration has been developed by leading managers in the field and focuses on promoting rust resistance, conserving genetic diversity, saving seed sources, and employing restoration treatments (Keane et al. 2012). These strategies are applied across the range of whitebark pine and rely on the collaboration of land managers, scientists, and academics. Seed Source The most promising strategy for restoration of whitebark pine is the out-planting of blister rust resistant seedlings (Keane et al. 2012). Due to the continuous loss of mature cone-bearing whitebark pine, it is necessary to collect seed for blister rust resistance screening, genetic conservation, and out-planting... For the large-scale planting of 36,000 whitebark pine seedlings on the Eureka Basin Burn in the Beaverhead-Deerlodge National Forest, the first year survival of the 800 seedling subsample was high overall (94%). A method for examining how seedling-level planting variables such as colonization by suilloid ectomycorrhizal fungi, microsite type and position, slope, and potential soil moisture (TWI) affect seedling health and survival was developed and seedlings were monitored 3 and 14 months after planting. Further monitoring will continue to examine how long term seedling success is affected by these variables.
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    The use of native ectomycorrhizal fungi in the restoration of whitebark pine
    (Montana State University - Bozeman, College of Agriculture, 2012) Lonergan, Erin Rebecca; Chairperson, Graduate Committee: Cathy L. Cripps.
    Whitebark pine (Pinus albicaulis) is an endangered keystone species in western North America. Populations are being decimated by white pine blister rust, mountain pine beetles and fire suppression. Large restoration efforts that include the planting of 200,000 rust-resistant seedlings are ongoing, but survival rates are low. Conifers are routinely inoculated with ectomycorrhizal fungi in the greenhouse to enhance out-planting success, but this has not been tried with whitebark pine. The goal of this project is to examine the use of native ectomycorrhizal fungi in restoration of whitebark pine with a greenhouse and field study. A main goal of the greenhouse study was to determine if low nitrogen fertilizer is conducive to ectomycorrhizal colonization by the native fungus, Suillus sibiricus. The effects of dried/fresh inoculum, short or long containers, and the drip/injection method were also tested. Results showed that mycorrhizal colonization was maintained with a low nitrogen fertilizer (4-25-15 NPK), although colonization declined at higher levels. Long containers were more conducive to mycorrhizal colonization, but differences were minimal for other variables. The field study conducted at Summit Lake in Waterton Lakes National Park is part of an effort to combat seriously declining pine populations. One thousand seedlings, half inoculated with Suillus sibiricus, were planted in clusters of three in four site condition combinations: burned/unburned areas, with and without beargrass. Survival was higher than for other studies one (95%) and two years (69%) after planting (2010). Results could be due to favorable spring conditions, conducive site conditions (terra-torching), and mycorrhizal inoculation on certain sites. Survival was 24% higher on burns in comparison to unburned sites; microsite increased survival across all sites. Effects of mycorrhizal inoculation were site dependent and survival was increased 17-23% on unburned sites with beargrass; inoculation did not impact seedling survival on burns. Survival was lowest (38%) on poor planting sites (unburned, no beargrass) but these sites benefited greatly from microsite presence. Data suggest site conditions strongly influence early seedling survival and that mycorrhizal inoculation may be beneficial when soil fungi are restricted. Longer term monitoring is necessary to determine how variables affect seedling survival in the future.
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    Impact of severe fire on ectomycorrhizal fungi of whitebark pine seedlings
    (Montana State University - Bozeman, College of Agriculture, 2009) Trusty, Paul Evan; Chairperson, Graduate Committee: Cathy L. Cripps.
    Whitebark pine (Pinus albicaulis) is a threatened keystone species in subalpine zones of Western North America critical to watersheds and maintenance of high elevation biodiversity. Pine nuts are an important food for wildlife including grizzly bears. Whitebark pine stands have experienced losses up to 90% due to white pine blister rust, mountain pine beetles and replacement due to fire suppression. Active management strategies include letting natural fires burn or applying prescribed fires to clear understory fir, stimulate seedling regeneration and provide openings for nutcrackers to plant seeds. However, post-fire plantings of rust-resistant seedlings have low survival rates. This study evaluated the impact of fire on the mycorrhizal fungi which are obligate mutualists with whitebark pine and to address management concerns. The 2001 Fridley fire burned a portion of a mature whitebark pine forest and a year later 20,000 seedlings were planted. After four years, natural and planted seedlings, on the burn and controls in the adjacent unburned forest were well colonized by mycorrhizal fungi (>90%) although a portion may be nursery E-strain. The severe burn reduced mycorrhizal diversity 27% on natural and planted seedlings and caused a significant shift in mycorrhizal species (determined by ITS sequencing, principal component analysis and multidimensional scaling). Seedlings in the burn (natural and planted) were dominated by Pseudotomentella nigra, Wilcoxina species and Amphinema byssoides while natural seedlings in unburned forest hosted mainly Cenococcum geophilum and Piloderma byssinum. Differences were minimal between planted and natural seedlings in the burn, but roots of planted pines retained the container shape. The functional significance of a species shift to seedling survival is not yet known. Seedlings in all treatments hosted suilloid fungi (Rhizopogon, Suillus) important in pine establishment. A greenhouse bioassay of burned and unburned soils using nursery seedlings did not reflect the full diversity found in the field study, but did reveal suilloid fungi indicating that bioassays can be used as a pre-planting assessment tool for this group. Despite high mycorrhization and availability of suilloids, seedling survival was low (22-42%) suggesting the timing/type of mycorrhization and/or other biotic/abiotic factors are a concern.
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