Limited overall impacts of ectomycorrhizal inoculation on recruitment of boreal trees into Arctic tundra following wildfire belie species-specific responses.

Autor: Hewitt RE; Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, Alaska, United States of America.; Center for Ecosystem Science and Society, Northern Arizona University, Flagstaff, Arizona, United States of America., Chapin FS 3rd; Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, Alaska, United States of America., Hollingsworth TN; US Forest Service, Pacific Northwest Research Station, Boreal Ecology Cooperative Research Unit, Fairbanks, Alaska, United States of America., Mack MC; Center for Ecosystem Science and Society, Northern Arizona University, Flagstaff, Arizona, United States of America., Rocha AV; Department of Biological Sciences and the Environmental Change Initiative, University of Notre Dame, Notre Dame, Indiana, United States of America., Taylor DL; Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, Alaska, United States of America.; Department of Biology, University of New Mexico, Albuquerque, New Mexico, United States of America.
Jazyk: angličtina
Zdroj: PloS one [PLoS One] 2020 Jul 09; Vol. 15 (7), pp. e0235932. Date of Electronic Publication: 2020 Jul 09 (Print Publication: 2020).
DOI: 10.1371/journal.pone.0235932
Abstrakt: We tested whether post-fire seedling establishment of common boreal tree and expanding shrub species at treeline and in Arctic tundra is facilitated by co-migration of boreal forest mycorrhizal fungi. Wildfires are anticipated to facilitate biome shifts at the forest-tundra ecotone by improving seedbed conditions for recruiting boreal species; at the same time fire alters the composition and availability of mycorrhizal fungi critical to seedling performance. To determine the role of root-associated fungi (RAF) in post-fire seedling recruitment and future biome shifts, we outplanted four dominant boreal tree and shrub species inoculated with one of three treatments at treeline and in tundra: burned boreal forest, unburned boreal forest, or a control treatment of sterilized inoculum. We compared survivorship, growth, and physiological performance of the seedlings in relation to mycorrhizal inoculum treatment and among host species, characterized the RAF communities based on ITS-rDNA sequencing of individual root tips sampled from surviving seedlings, and tested for correlations between RAF composition and the inoculation treatments, host species, and duration of the experiment. We explored correlations between RAF composition and seedling metrics. Both live and sterile autoclaved inoculation treatments had similar effects on seedling survivorship and growth for all species. RAF composition did not vary by treatment, suggesting that most colonization was due to local fungi. However, seedling traits and growth were correlated with RAF species composition, colonization, and the relative abundance of specific RAF taxa. Picea sp. performance in particular showed strong co-variation with RAF metrics. Our results suggest that mycorrhizal co-migration is not a primary limiting factor to boreal seedling recruitment because the experimental provision of inoculum did not affect seedling recruitment; yet, RAF did influence seedling performance, particularly resident RAF at treeline and in tundra, suggesting that mycorrhizal fungi are important to vegetation processes at the treeline-tundra ecotone.
Competing Interests: The authors have declared that no competing interests exist.
Databáze: MEDLINE
Externí odkaz:
Nepřihlášeným uživatelům se plný text nezobrazuje