TY - JOUR
T1 - Identifying Functional Impacts of Heat-Resistant Fungi on Boreal Forest Recovery After Wildfire
AU - Day, Nicola J.
AU - Cumming, Steven G.
AU - Dunfield, Kari E.
AU - Johnstone, Jill F.
AU - Mack, Michelle C.
AU - Reid, Kirsten A.
AU - Turetsky, Merritt R.
AU - Walker, Xanthe J.
AU - Baltzer, Jennifer L.
N1 - Funding Information:
In kind support was provided by the Wilfrid Laurier University - GNWT Partnership and the Bonanza Creek LTER program. We thank the Aurora Research Institute (Research License 15879), the Ka'a'gee Tu First Nation, the Tłicho Government, and the Wek'éezhìi Renewable Resources Board for support. Sand was graciously donated by Hutcheson Sand and Mixes. We thank H. Nguyen for initial discussions of heat-resistant fungi and advice on isolation methods, A. Sniderhan for making the maps, K. Stevens for microscope use, G. Moreno-Hagelsieb for bioinformatics assistance, and numerous students and technicians for providing field and lab assistance. Funding. This article is part of Project 170 of the Government of the Northwest Territories (GNWT) Department of Environment and Natural Resources Cumulative Impacts Monitoring Program (JB, JJ, and SC). Additional funding for this research was provided by a Natural Science and Engineering Research Council (NSERC) Post-doctoral Fellowship (ND), NSERC Changing Cold Regions Network, Northern Scientific Training Program, NSERC Discovery (MT), a National Science Foundation DEB RAPID (#1542150), NASA Arctic Boreal and Vulnerability Experiment (ABoVE) Legacy Carbon grant NNX15AT71A (MM), and CFREF Global Water Futures funding to the Northern Water Futures project.
Funding Information:
This article is part of Project 170 of the Government of the Northwest Territories (GNWT) Department of Environment and Natural Resources Cumulative Impacts Monitoring Program (JB, JJ, and SC). Additional funding for this research was provided by a Natural Science and Engineering Research Council (NSERC) Post-doctoral Fellowship (ND), NSERC Changing Cold Regions Network, Northern Scientific Training Program,
Funding Information:
In kind support was provided by the Wilfrid Laurier University -GNWT Partnership and the Bonanza Creek LTER program. We thank the Aurora Research Institute (Research License 15879), the Ka’a’gee Tu First Nation, the Tłicho Government, and the Wek’éezhìi Renewable Resources Board for support. Sand was graciously donated by Hutcheson Sand and Mixes. We thank H. Nguyen for initial discussions of heat-resistant fungi and advice on isolation methods, A. Sniderhan for making the maps, K. Stevens for microscope use, G. Moreno-Hagelsieb for bioinformatics assistance, and numerous students and technicians for providing field and lab assistance.
Publisher Copyright:
© Copyright © 2020 Day, Cumming, Dunfield, Johnstone, Mack, Reid, Turetsky, Walker and Baltzer.
PY - 2020/6/9
Y1 - 2020/6/9
N2 - Fungi play key roles in carbon (C) dynamics of ecosystems: saprotrophs decompose organic material and return C in the nutrient cycle, and mycorrhizal species support plants that accumulate C through photosynthesis. The identities and functions of extremophile fungi present after fire can influence C dynamics, particularly because plant-fungal relationships are often species-specific. However, little is known about the function and distribution of fungi that survive fires. We aim to assess the distribution of heat-resistant soil fungi across burned stands of boreal forest in the Northwest Territories, Canada, and understand their functions in relation to decomposition and tree seedling growth. We cultured and identified fungi from heat-treated soils and linked sequences from known taxa with high throughput sequencing fungal data (Illumina MiSeq, ITS1) from soils collected in 47 plots. We assessed functions under controlled conditions by inoculating litter and seedlings with heat-resistant fungi to assess decomposition and effects on seedling growth, respectively, for black spruce (Picea mariana), birch (Betula papyrifera), and jack pine (Pinus banksiana). We also measured litter decomposition rates and seedling densities in the field without inoculation. We isolated seven taxa of heat-resistant fungi and found their relative abundances were not associated with environmental or fire characteristics. Under controlled conditions, Fayodia gracilipes and Penicillium arenicola decomposed birch, but no taxa decomposed black spruce litter significantly more than the control treatment. Seedlings showed reduced biomass and/or mortality when inoculated with at least one of the fungal taxa. Penicillium turbatum reduced growth and/or caused mortality of all three species of seedlings. In the field, birch litter decomposed faster in stands with greater pre-fire proportion of black spruce, while black spruce litter decomposed faster in stands experiencing longer fire-free intervals. Densities of seedlings that had germinated since fire were positively associated with ectomycorrhizal richness while there were fewer conifer seedlings with greater heat-resistant fungal abundance. Overall, our study suggests that extremophile fungi present after fires have multiple functions and may have unexpected negative effects on forest functioning and regeneration. In particular, heat-resistant fungi after fires may promote shifts away from conifer dominance that are observed in these boreal forests.
AB - Fungi play key roles in carbon (C) dynamics of ecosystems: saprotrophs decompose organic material and return C in the nutrient cycle, and mycorrhizal species support plants that accumulate C through photosynthesis. The identities and functions of extremophile fungi present after fire can influence C dynamics, particularly because plant-fungal relationships are often species-specific. However, little is known about the function and distribution of fungi that survive fires. We aim to assess the distribution of heat-resistant soil fungi across burned stands of boreal forest in the Northwest Territories, Canada, and understand their functions in relation to decomposition and tree seedling growth. We cultured and identified fungi from heat-treated soils and linked sequences from known taxa with high throughput sequencing fungal data (Illumina MiSeq, ITS1) from soils collected in 47 plots. We assessed functions under controlled conditions by inoculating litter and seedlings with heat-resistant fungi to assess decomposition and effects on seedling growth, respectively, for black spruce (Picea mariana), birch (Betula papyrifera), and jack pine (Pinus banksiana). We also measured litter decomposition rates and seedling densities in the field without inoculation. We isolated seven taxa of heat-resistant fungi and found their relative abundances were not associated with environmental or fire characteristics. Under controlled conditions, Fayodia gracilipes and Penicillium arenicola decomposed birch, but no taxa decomposed black spruce litter significantly more than the control treatment. Seedlings showed reduced biomass and/or mortality when inoculated with at least one of the fungal taxa. Penicillium turbatum reduced growth and/or caused mortality of all three species of seedlings. In the field, birch litter decomposed faster in stands with greater pre-fire proportion of black spruce, while black spruce litter decomposed faster in stands experiencing longer fire-free intervals. Densities of seedlings that had germinated since fire were positively associated with ectomycorrhizal richness while there were fewer conifer seedlings with greater heat-resistant fungal abundance. Overall, our study suggests that extremophile fungi present after fires have multiple functions and may have unexpected negative effects on forest functioning and regeneration. In particular, heat-resistant fungi after fires may promote shifts away from conifer dominance that are observed in these boreal forests.
KW - Northwest Territories
KW - Taiga plains
KW - boreal
KW - extremophile
KW - litter decomposition
KW - mycorrhiza
KW - saprotroph
KW - seedlings
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UR - http://www.scopus.com/inward/citedby.url?scp=85105321212&partnerID=8YFLogxK
U2 - 10.3389/ffgc.2020.00068
DO - 10.3389/ffgc.2020.00068
M3 - Article
AN - SCOPUS:85105321212
SN - 2624-893X
VL - 3
JO - Frontiers in Forests and Global Change
JF - Frontiers in Forests and Global Change
M1 - 68
ER -