MSA - Ecology/Pathology
Trusty, Paul E , Cripps, Cathy L .
Influence of severe fire on planted and natural whitebark pine seedlings in the Greater Yellowstone Area: Ecology and management implications.
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 where ranges overlap. Whitebark pine has 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 impacts of fire on mycorrhizal colonization of whitebark pine seedlings from an ecological perspective 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 species (ITS sequencing); 60% of variation is accounted for by ‘burning’ according to PCA 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, Piloderma byssinum and suilloids. The functional significance of a species shift to seedling survival is not yet known. Four years after the burn, seedlings in all treatments hosted suilloid fungi (Rhizopogon, Suillus) important in pine establishment. Despite high mycorrhization and availability of suilloids, seedling survival was low (22-42%) suggesting timing/type of mycorrhization and/or other biotic/abiotic factors are a concern.
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1 - Montana State University, Plant Sciences and Plant Pathology, 119 Plant Biosciences Building, Bozeman, MT, 59717-3150, USA
2 - Montana State University, Plant Sciences and Plant Pathology Dept, 119 Plant Biosciences Building, Bozeman, MT, 59717-3150, USA
Presentation Type: Poster:Posters for Topics
Location: Event Tent/Cliff Lodge
Date: Tuesday, July 28th, 2009
Time: 5:30 PM