Following a pine beetle epidemic in British Columbia, Canada, we investigated the effect of fire severity on rhizosphere soil chemistry and ectomycorrhizal fungi (ECM) and associated denitrifying and nitrogen (N)-fixing bacteria in the root systems of regenerating lodgepole pine seedlings at two site types (wet and dry) and three fire severities (low, moderate, and high). The site type was found to have a much larger impact on all measurements than fire severity. Wet and dry sites differed significantly for almost all soil properties measured, with higher values identified from wet types, except for pH and percent sand that were greater on dry sites. Fire severity caused few changes in soil chemical status. Generally, bacterial communities differed little, whereas ECM morphotype analysis revealed ectomycorrhizal diversity was lower on dry sites, with a corresponding division in community structure between wet and dry sites. Molecular profiling of the fungal ITS region confirmed these results, with a clear difference in community structure seen between wet and dry sites. The ability of ECM fungi to colonize seedlings growing in both wet and dry soils may positively contribute to subsequent regeneration. We conclude that despite consecutive landscape disturbances (mountain pine beetle infestation followed by wildfire), the "signature" of moisture on chemistry and ECM community structure remained pronounced.

• MeSH
• Bacteria classification   genetics   isolation & purification   metabolism   MeSH
• Pinus growth & development   microbiology   parasitology   MeSH
• Coleoptera physiology   MeSH
• Nitrogen metabolism   MeSH
• Ecosystem MeSH
• Fungi classification   genetics   isolation & purification   MeSH
• Mycorrhizae classification   genetics   growth & development   isolation & purification   MeSH
• Plant Diseases parasitology   MeSH
• Fires MeSH
• Soil chemistry   MeSH
• Rhizosphere MeSH
• Trees growth & development   microbiology   parasitology   MeSH
• Water analysis   MeSH
• Animals MeSH
• Check Tag
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Comparative Study MeSH