Site properties have a stronger influence than fire severity on ectomycorrhizal fungi and associated N-cycling bacteria in regenerating post-beetle-killed lodgepole pine forests

• Published in: Folia microbiologica Vol. 60; no. 5; pp. 399 - 410
• Main Authors: Kennedy, Nabla M, Robertson, Susan J, Green, D. Scott, Scholefield, Scott R, Arocena, Joselito M, Tackaberry, Linda E, Massicotte, Hugues B, Egger, Keith N
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Netherlands 01.09.2015; Springer Nature B.V
• Subjects: Animals; Applied Microbiology; Bacteria; Bacteria - classification; Bacteria - genetics; Bacteria - isolation & purification; Bacteria - metabolism; bacterial communities; Biomedical and Life Sciences; Coleoptera - physiology; community structure; coniferous forests; Dendroctonus ponderosae; denitrification; Ecosystem; ectomycorrhizae; Environmental Engineering/Biotechnology; fire severity; Fires; Forest soils; Fungi; Fungi - classification; Fungi - genetics; Fungi - isolation & purification; Immunology; Insects; internal transcribed spacers; landscapes; Life Sciences; Microbiology; Mycorrhizae - classification; Mycorrhizae - genetics; Mycorrhizae - growth & development; Mycorrhizae - isolation & purification; mycorrhizal fungi; nitrogen; Nitrogen - metabolism; Pinus - growth & development; Pinus - microbiology; Pinus - parasitology; Pinus contorta var. latifolia; Plant Diseases - parasitology; Rhizosphere; root systems; sand; seedlings; Soil - chemistry; soil properties; Trees - growth & development; Trees - microbiology; Trees - parasitology; Water - analysis; wildfires; British Columbia; Fire Severity; Mountain Pine Beetle; Terminal Restriction Fragment Length Polymorphism; British Columbia; Fungal Community
• ISSN: 0015-5632; 1874-9356
• DOI: 10.1007/s12223-014-0374-7

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.