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McPolin MC, Kranabetter JM, Philpott TJ, Hawkins BJ. Sporocarp nutrition of ectomycorrhizal fungi indicates an important role for endemic species in a high productivity temperate rainforest. New Phytol 2024; 242:1603-1613. [PMID: 37771241 DOI: 10.1111/nph.19280] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/09/2023] [Accepted: 09/04/2023] [Indexed: 09/30/2023]
Abstract
Endemic species of ectomycorrhizal fungi (EMF) are found throughout many biomes, but it is unclear whether their localized distribution is dictated by habitat filtering or geographical barriers to dispersal. We examined community composition (via long-read metabarcoding) and differences in sporocarp nutrition between endemic and cosmopolitan EMF species across perhumid temperate rainforests of British Columbia, characterized by soils with high nitrogen (N) supply alongside low phosphorus (P) and cation availability. Endemic EMF species, representing almost half of the community, had significantly greater sporocarp N (24% higher), potassium (+16%), and magnesium (+17%) concentrations than cosmopolitan species. Sporocarp P concentrations were comparatively low and did not differ by fungal range. However, sporocarp N% and P% were well correlated, supporting evidence for linkages in N and P acquisition. Endemics were more likely to occur on Tsuga heterophylla (a disjunct host genus) than Picea sitchensis (a circumpolar genus). The Inocybaceae and Thelephoraceae families had high proportions of endemic taxa, while species in Cortinariaceae were largely cosmopolitan, indicating some niche conservatism among genera. We conclude that superior adaptive traits in relation to perhumid soils were skewed toward the endemic community, underscoring the potentially important contribution of these localized fungi to rainforest nutrition and productivity.
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Affiliation(s)
- M Claire McPolin
- Centre for Forest Biology, University of Victoria, PO Box 3020, STN CSC, Victoria, BC, V8W 3N5, Canada
| | - J Marty Kranabetter
- British Columbia Ministry of Forests, PO Box 9536, Stn Prov Govt, Victoria, BC, V8W 9C4, Canada
| | - Tim J Philpott
- British Columbia Ministry of Forests, 200-640 Borland St., Williams Lake, BC, V2G 4T1, Canada
| | - Barbara J Hawkins
- Centre for Forest Biology, University of Victoria, PO Box 3020, STN CSC, Victoria, BC, V8W 3N5, Canada
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Nehring L, Kranabetter JM, Harper GJ, Hawkins BJ. Tree-ring δ15N as an indicator of nitrogen dynamics in stands with N2-fixing Alnus rubra. Tree Physiol 2023; 43:2064-2075. [PMID: 37672228 DOI: 10.1093/treephys/tpad110] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/22/2023] [Revised: 08/14/2023] [Accepted: 09/03/2023] [Indexed: 09/07/2023]
Abstract
Tree-ring δ15N may depict site-specific, long-term patterns in nitrogen (N) dynamics under N2-fixing species, but field trials with N2-fixing tree species are lacking and the relationship of temporal patterns in tree-ring δ15N to soil N dynamics is controversial. We examined whether the tree-ring δ15N of N2-fixing red alder (Alnus rubra Bong.) would mirror N accretion rates and δ15N of soils and whether the influence of alder-fixed N could be observed in the wood of a neighboring conifer. We sampled a 27-year-old replacement series trial on south-eastern Vancouver Island, with red alder and coastal Douglas-fir (Pseudotsuga menziesii [Mirb.] Franco) planted in five proportions (0/100, 11/89, 25/75, 50/50 and 100/0) at a uniform stem density. An escalation in forest floor N content was evident with an increasing proportion of red alder, equivalent to a difference of ~750 kg N ha-1 between 100% Douglas-fir versus 100% alder. The forest floor horizon also had high δ15N values in treatments with more red alder. Red alder had a consistent quadratic fit in tree-ring δ15N over time, with a net increase of $\sim$1.5‰, on average, from initial values, followed by a plateau or slight decline. Douglas-fir tree-ring δ15N, in contrast, was largely unchanged over time (in three of four plots) but was significantly higher in the 50/50 mix. The minor differences in current leaf litter N content and δ15N between alder and Douglas-fir, coupled with declining growth in red alder, suggests the plateau or declining trend in alder tree-ring δ15N could coincide with lower N2-fixation rates, potentially by loss in alder vigor at canopy closure, or down-regulation via nitrate availability.
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Affiliation(s)
- L Nehring
- Centre for Forest Biology, University of Victoria, PO Box 3020, STN CSC, 3800 Finnerty Road,Victoria, British Columbia V8P 5C2, Canada
| | - J M Kranabetter
- British Columbia Ministry of Forests, PO Box 9536, Stn Prov Govt, 4300 North Road, Victoria, British Columbia V8Z 5J3, Canada
| | - G J Harper
- British Columbia Ministry of Forests, 4th Floor - 545 Superior Street, Victoria, British Columbia V8V 1T7, Canada
| | - B J Hawkins
- Centre for Forest Biology, University of Victoria, PO Box 3020, STN CSC, 3800 Finnerty Road,Victoria, British Columbia V8P 5C2, Canada
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Kranabetter JM, Robbins S, Hawkins BJ. Host population effects on ectomycorrhizal fungi vary between low and high phosphorus soils of temperate rainforests. Mycorrhiza 2023; 33:199-209. [PMID: 36947254 DOI: 10.1007/s00572-023-01109-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2022] [Accepted: 03/13/2023] [Indexed: 06/08/2023]
Abstract
Geographic distinctions in the affinity of tree populations for select ectomycorrhizal fungi (EMF) may occur where strong edaphic pressures act on fungal communities and their hosts. We examine this premise for Pseudotsuga menziesii var. menziesii of southwest British Columbia, using ten native seedlots collected from a range of mean annual precipitation (MAP), as a proxy for podzolization extent and phosphorus (P) deficiencies, and evaluated in contrasting low P and high P soils. After two growing seasons, seedling biomass in the high P soil dwarfed that of the low P soil, and better growth rates under high P were detected for populations from very dry and very wet origins. EMF communities on the high P soil displayed more symmetry among host populations than the low P soil (average community dissimilarity of 0.20% vs. 0.39%, respectively). Seedling foliar P% differed slightly but significantly in relation to MAP of origin. EMF species richness varied significantly among host populations but independently of climatic parameters. There were significant shifts in EMF species abundance related to seedlot MAP, particularly on the low P soil where nonlinear relationships were found for Wilcoxina mikolae, Hyaloscypha finlandica, and Rhizopogon villosulus. Despite efforts to enhance colonization by native fungi, the predominance of ruderal EMF species hindered a realistic evaluation of local adaptation among host-fungi populations. Nevertheless, the shifting affinity in taxa abundance and wider community disparity on low P soil reflected the potential for a consequential host genetic effect related to geographical patterns in P availability across temperate rainforests.
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Affiliation(s)
- J M Kranabetter
- British Columbia Ministry of Forests, P.O. Box 9536, Stn Prov Govt, Victoria, B.C., Canada, V8W 9C4.
| | - S Robbins
- Centre for Forest Biology, University of Victoria, P.O. Box 3020, STN CSC, Victoria, B.C., Canada, V8W 3N5
| | - B J Hawkins
- Centre for Forest Biology, University of Victoria, P.O. Box 3020, STN CSC, Victoria, B.C., Canada, V8W 3N5
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McPolin MC, Kranabetter JM. Influence of endemic versus cosmopolitan species on the local assembly of ectomycorrhizal fungal communities. New Phytol 2021; 229:2395-2399. [PMID: 33091170 DOI: 10.1111/nph.17015] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2020] [Accepted: 10/13/2020] [Indexed: 06/11/2023]
Affiliation(s)
- M Claire McPolin
- Centre for Forest Biology, PO Box 3020, STN CSC, Victoria, BC, V8W 3N5, Canada
| | - J Marty Kranabetter
- British Columbia Ministry of Forests, Lands, Natural Resource Operations and Rural Development, PO Box 9536, Stn Prov Govt, Victoria, BC, V8W 9C4, Canada
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Meeds JA, Marty Kranabetter J, Zigg I, Dunn D, Miros F, Shipley P, Jones MD. Phosphorus deficiencies invoke optimal allocation of exoenzymes by ectomycorrhizas. ISME J 2021; 15:1478-1489. [PMID: 33420298 PMCID: PMC8114911 DOI: 10.1038/s41396-020-00864-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/19/2020] [Revised: 11/20/2020] [Accepted: 11/30/2020] [Indexed: 11/09/2022]
Abstract
Ectomycorrhizal (EM) fungi can acquire phosphorus (P) through the production of extracellular hydrolytic enzymes (exoenzymes), but it is unclear as to the manner and extent native EM fungal communities respond to declining soil P availability. We examined the activity of six exoenzymes (xylosidase, N-acetyl glucosaminidase, β-glucosidase, acid phosphomonoesterase, acid phosphodiesterase [APD], laccase) from EM roots of Pseudotsuga menzesii across a soil podzolization gradient of coastal British Columbia. We found that APD activity increased fourfold in a curvilinear association with declining inorganic P. Exoenzyme activity was not related to organic P content, but at a finer resolution using 31P-NMR, there was a strong positive relationship between APD activity and the ratio of phosphodiesters to orthophosphate of surface organic horizons (forest floors). Substantial increases (two- to fivefold) in most exoenzymes were aligned with declining foliar P concentrations of P. menzesii, but responses were statistically better in relation to foliar nitrogen (N):P ratios. EM fungal species with consistently high production of key exoenzymes were exclusive to Podzol plots. Phosphorus deficiencies in relation to N limitations may provide the best predictor of exoenzyme investment, reflecting an optimal allocation strategy for EM fungi. Resource constraints contribute to species turnover and the assembly of distinct, well-adapted EM fungal communities.
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Affiliation(s)
- Justin A Meeds
- Biology Department, University of British Columbia, Okanagan Campus 1177 Research Road, Kelowna, BC, V4V 1V7, Canada
| | - J Marty Kranabetter
- British Columbia Ministry of Forests, Lands and Natural Resource Operations, P.O. Box 9536, Stn Prov Govt, Victoria, BC, V8W 9C4, Canada.
| | - Ieva Zigg
- Biology Department, University of British Columbia, Okanagan Campus 1177 Research Road, Kelowna, BC, V4V 1V7, Canada.,Chemistry Department, University of British Columbia, Okanagan Campus 3187 University Way, Kelowna, BC, V4V 1V7, Canada
| | - Dave Dunn
- Natural Resources Canada, Pacific Forestry Centre, 506 Burnside Road West, Victoria, BC, V8Z 1M5, Canada
| | - François Miros
- Chemistry Department, University of British Columbia, Okanagan Campus 3187 University Way, Kelowna, BC, V4V 1V7, Canada
| | - Paul Shipley
- Chemistry Department, University of British Columbia, Okanagan Campus 3187 University Way, Kelowna, BC, V4V 1V7, Canada
| | - Melanie D Jones
- Biology Department, University of British Columbia, Okanagan Campus 1177 Research Road, Kelowna, BC, V4V 1V7, Canada
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Kranabetter JM, Harman-Denhoed R, Hawkins BJ. Saprotrophic and ectomycorrhizal fungal sporocarp stoichiometry (C : N : P) across temperate rainforests as evidence of shared nutrient constraints among symbionts. New Phytol 2019; 221:482-492. [PMID: 30084239 DOI: 10.1111/nph.15380] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2018] [Accepted: 07/07/2018] [Indexed: 06/08/2023]
Abstract
Quantifying nutritional dynamics of free-living saprotrophs and symbiotic ectomycorrhizal fungi in the field is challenging, but the stoichiometry of fruiting bodies (sporocarps) may be an effective methodology for this purpose. Carbon (C), nitrogen (N) and phosphorus (P) concentrations of soils, foliage and 146 sporocarp collections were analyzed from 14 Pseudotsuga menziesii var. menziesii stands across a podzolization gradient on Vancouver Island (Canada). N and P concentrations were considerably higher in saprotrophic fungi. Fungal N% increased with soil N content at a greater rate for saprotrophs than ectomycorrhizal fungi, while fungal P% of saprotrophs was more constrained. Fungal N : P was more responsive to soil N : P for ectomycorrhizal fungi (homeostatic regulation coefficient 'H' = 2.9) than saprotrophs (H = 5.9), while N : P of ectomycorrhizal fungi and host tree foliage scaled almost identically. Results underscore the role of ectomycorrhizal fungi as nutrient conduits, supporting host trees, whereas saprotrophs maintain a greater degree of nutritional homeostasis. Site nutrient constraints were shared in equal measure between ectomycorrhizal fungi and host trees, particularly for P, suggesting neither partner benefits from enhanced nutrition at the expense of the other. Sporocarp stoichiometry provides new insights into mycorrhizal relationships and illustrates pervasive P deficiencies across temperate rainforests of the Pacific Northwest.
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Affiliation(s)
- J Marty Kranabetter
- British Columbia Ministry of Forests, Lands and Natural Resource Operations, PO Box 9536, Stn Prov Govt, Victoria, BC, V8W 9C4, Canada
| | - Rachael Harman-Denhoed
- Centre for Forest Biology, University of Victoria, PO Box 3020, STN CSC, Victoria, BC, V8W 3N5, Canada
| | - Barbara J Hawkins
- Centre for Forest Biology, University of Victoria, PO Box 3020, STN CSC, Victoria, BC, V8W 3N5, Canada
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Wilhelm RC, Cardenas E, Maas KR, Leung H, McNeil L, Berch S, Chapman W, Hope G, Kranabetter JM, Dubé S, Busse M, Fleming R, Hazlett P, Webster KL, Morris D, Scott DA, Mohn WW. Biogeography and organic matter removal shape long-term effects of timber harvesting on forest soil microbial communities. ISME J 2017; 11:2552-2568. [PMID: 28753210 DOI: 10.1038/ismej.2017.109] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/04/2016] [Revised: 05/03/2017] [Accepted: 05/19/2017] [Indexed: 11/09/2022]
Abstract
The growing demand for renewable, carbon-neutral materials and energy is leading to intensified forest land-use. The long-term ecological challenges associated with maintaining soil fertility in managed forests are not yet known, in part due to the complexity of soil microbial communities and the heterogeneity of forest soils. This study determined the long-term effects of timber harvesting, accompanied by varied organic matter (OM) removal, on bacterial and fungal soil populations in 11- to 17-year-old reforested coniferous plantations at 18 sites across North America. Analysis of highly replicated 16 S rRNA gene and ITS region pyrotag libraries and shotgun metagenomes demonstrated consistent changes in microbial communities in harvested plots that included the expansion of desiccation- and heat-tolerant organisms and decline in diversity of ectomycorrhizal fungi. However, the majority of taxa, including the most abundant and cosmopolitan groups, were unaffected by harvesting. Shifts in microbial populations that corresponded to increased temperature and soil dryness were moderated by OM retention, which also selected for sub-populations of fungal decomposers. Biogeographical differences in the distribution of taxa as well as local edaphic and environmental conditions produced substantial variation in the effects of harvesting. This extensive molecular-based investigation of forest soil advances our understanding of forest disturbance and lays the foundation for monitoring long-term impacts of timber harvesting.
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Affiliation(s)
- Roland C Wilhelm
- Department of Microbiology &Immunology, Life Sciences Institute, University of British Columbia, Vancouver, British Columbia, Canada
| | - Erick Cardenas
- Department of Microbiology &Immunology, Life Sciences Institute, University of British Columbia, Vancouver, British Columbia, Canada
| | - Kendra R Maas
- Department of Microbiology &Immunology, Life Sciences Institute, University of British Columbia, Vancouver, British Columbia, Canada
| | - Hilary Leung
- Department of Microbiology &Immunology, Life Sciences Institute, University of British Columbia, Vancouver, British Columbia, Canada
| | - Larisa McNeil
- Department of Microbiology &Immunology, Life Sciences Institute, University of British Columbia, Vancouver, British Columbia, Canada
| | - Shannon Berch
- British Columbia Ministry of Forests, Lands and Natural Resource Operations, Victoria, British Columbia, Canada
| | - William Chapman
- British Columbia Ministry of Forests, Lands and Natural Resource Operations, Victoria, British Columbia, Canada
| | - Graeme Hope
- British Columbia Ministry of Forests, Lands and Natural Resource Operations, Victoria, British Columbia, Canada
| | - J M Kranabetter
- British Columbia Ministry of Forests, Lands and Natural Resource Operations, Victoria, British Columbia, Canada
| | - Stephane Dubé
- College of New Caledonia, Prince George, British Columbia, Canada
| | | | - Robert Fleming
- Natural Resources Canada, Canadian Forest Service, Great Lakes Forestry Centre, Sault Ste. Marie, Ontario, Canada
| | - Paul Hazlett
- Natural Resources Canada, Canadian Forest Service, Great Lakes Forestry Centre, Sault Ste. Marie, Ontario, Canada
| | - Kara L Webster
- Natural Resources Canada, Canadian Forest Service, Great Lakes Forestry Centre, Sault Ste. Marie, Ontario, Canada
| | - David Morris
- Ontario Ministry of Natural Resources, Thunder Bay, Ontario, Canada
| | | | - William W Mohn
- Department of Microbiology &Immunology, Life Sciences Institute, University of British Columbia, Vancouver, British Columbia, Canada
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Kranabetter JM, McLauchlan KK, Enders SK, Fraterrigo JM, Higuera PE, Morris JL, Rastetter EB, Barnes R, Buma B, Gavin DG, Gerhart LM, Gillson L, Hietz P, Mack MC, McNeil B, Perakis S. A Framework to Assess Biogeochemical Response to Ecosystem Disturbance Using Nutrient Partitioning Ratios. Ecosystems 2015. [DOI: 10.1007/s10021-015-9934-1] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Kranabetter JM, Stoehr M, O'Neill GA. Ectomycorrhizal fungal maladaptation and growth reductions associated with assisted migration of Douglas-fir. New Phytol 2015; 206:1135-1144. [PMID: 25623442 DOI: 10.1111/nph.13287] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/04/2014] [Accepted: 12/17/2014] [Indexed: 05/05/2023]
Abstract
Climatic adaptations are the foundation of conifer genecology, but populations also display variation in traits for nitrogen (N) utilization, along with some heritable specificity for ectomycorrhizal fungi (EMF). We examined soil and EMF influences on assisted migration of Douglas-fir (Pseudotsuga menziesii var. menziesii) by comparing two contrasting maritime populations planted up to 400 km northward in southwestern British Columbia. Soil N availability and host N status (via δ(15) N) were assessed across 12 maritime test sites, whereas EMF on local and introduced hosts were quantified by morphotyping with molecular analysis. Climatic transfer effects were only significant with soil N concentrations of test sites as a covariate, and illustrated how height growth was compromised for populations originating from relatively dry or cool maritime environments. We also found evidence for EMF maladaptation, where height declined by up to 15% with the extent of dissimilarity in EMF communities of southern populations relative to local hosts. The results demonstrate how geographic structure in belowground environments can contribute to conifer genecology. Differences in the inherent growth potential of conifers may be partly related to nutritional adaptations arising under native soil fertility, and optimization of this growth potential likely requires close affiliation with local EMF communities.
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Affiliation(s)
- J Marty Kranabetter
- BC Ministry of Forests, Lands and Natural Resource Operations, PO Box 9536 Stn Prov Govt, Victoria, BC, V8W 9C4, Canada
| | - Michael Stoehr
- BC Ministry of Forests, Lands and Natural Resource Operations, PO Box 9525 Stn Prov Govt, Victoria, BC, V8W 9C3, Canada
| | - Greg A O'Neill
- Kalamalka Forestry Centre, BC Ministry of Forests, Lands and Natural Resource Operations, 3401 Reservoir Road, Vernon, BC, V1B 2C7, Canada
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Kranabetter JM, Stoehr MU, O'Neill GA. Divergence in ectomycorrhizal communities with foreign Douglas-fir populations and implications for assisted migration. Ecol Appl 2012; 22:550-560. [PMID: 22611853 DOI: 10.1890/11-1514.1] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Assisted migration of forest trees has been widely proposed as a climate change adaptation strategy, but moving tree populations to match anticipated future climates may disrupt the geographically based, coevolved association suggested to exist between host trees and ectomycorrhizal fungal (EMF) communities. We explored this issue by examining the consistency of EMF communities among populations of 40 year-old Douglas-fir (Pseudotsuga menziesii var. menziesii) trees in a common-garden field trial using four provenances from contrasting coastal climates in southwestern British Columbia. Considerable variation in EMF community composition within test sites was found, ranging from 0.38 to 0.65 in the mean similarity index, and the divergence in EMF communities from local populations increased with site productivity. Clinal patterns in colonization success were detected for generalist and specialist EMF species on only the two productive test sites. Host population effects were limited to EMF species abundance rather than species loss, as richness per site averaged 15.0 among provenances and did not differ by transfer extent (up to 450 km), while Shannon's diversity index declined slightly. Large differences in colonization rates of specialist fungi, such as Tomentella stuposa and Clavulina cristata, raise the possibility that EMF communities maladapted to soil conditions contributed to the inferior growth of some host populations on productive sites. The results of the study suggest locally based specificity in host-fungal communities is likely a contributing factor in the outcome of provenance trials, and should be a consideration in analyzing seed-transfer effects and developing strategies for assisted migration.
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Affiliation(s)
- J M Kranabetter
- B.C. Ministry of Forests, Lands and Natural Resource Operations, P.O. Box 9536 Stn Prov Govt, Victoria, British Columbia V8W 9C4, Canada.
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Kranabetter JM, Friesen J, Gamiet S, Kroeger P. Epigeous fruiting bodies of ectomycorrhizal fungi as indicators of soil fertility and associated nitrogen status of boreal forests. Mycorrhiza 2009; 19:535-548. [PMID: 19449039 DOI: 10.1007/s00572-009-0255-0] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/04/2009] [Accepted: 04/27/2009] [Indexed: 05/27/2023]
Abstract
Soil fertility and associated nitrogen (N) status was a key ecosystem attribute, and surveys of ectomycorrhizal fungal (EMF) communities via epigeous fruiting bodies could provide an effective biotic indicator of forest soil productivity. We explored the utility of aboveground EMF communities in this regard by surveying sporocarps over a 3-year period from contrasting plant associations of southern old-growth boreal forests of British Columbia (Canada). Cumulative richness ranged from 39 to 89 EMF species per plot (0.15 ha) and followed a skewed parabolic correlation with foliar N concentrations and soil N availability. EMF species composition was consistently distinct in ordinations and strongly correlated to the increasing rates of N mineralization aligned with soil productivity. Approximately 40 EMF species were specialists, as they collectively indicated oligotrophic, mesotrophic, and eutrophic nutrient regimes, while the remaining species were categorized as broadly tolerant (distributed over 100% of the N gradient), partially intolerant (approximately 70%), or satellites (rare). The functional organization of EMF communities reflected by distribution classes could help define the ecological integrity of forests, which was characterized in this boreal landscape by an average allotment of 20 broadly tolerant, 25 partially intolerant, 15 specialist, and ten satellite species per plot. Epigeous fruiting bodies provided a disparate yet complementary view to the belowground assessment of EMF communities that was valuable in identifying indicators for ecosystem monitoring.
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Affiliation(s)
- J M Kranabetter
- British Columbia Ministry of Forests and Range, 4300 North Rd, Victoria, BC, Canada, V8Z 5J3.
| | - J Friesen
- Jodi Friesen Ecological Consulting, P.O. Box 15, Site F, Hazelton, BC, Canada, V0J 1Y0
| | - S Gamiet
- Mycology Resources, P.O. Box 2603, Clearbrook Station, Abbotsford, BC, Canada, V2T 6R4
| | - P Kroeger
- , 395 E 40th Ave, Vancouver, BC, Canada, V5W 1M1
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Kranabetter JM, Durall DM, MacKenzie WH. Diversity and species distribution of ectomycorrhizal fungi along productivity gradients of a southern boreal forest. Mycorrhiza 2009; 19:99-111. [PMID: 18941804 DOI: 10.1007/s00572-008-0208-z] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/26/2008] [Accepted: 10/09/2008] [Indexed: 05/26/2023]
Abstract
Coniferous forests with diverse ectomycorrhizal fungus (EMF) communities are associated with nutrient-poor, acidic soils but there is some debate whether EMF can be equally adapted to more productive, nitrogen-rich sites. We compared EMF species distribution and diversity along a replicated productivity gradient in a southern boreal forest of British Columbia (Canada). Roots from subalpine fir (Abies lasiocarpa) saplings of the understory were sampled and EMF species were identified by morphotypes supplemented with ITS rDNA analysis. There were significant changes in the distribution and abundance of 74 EMF species along the productivity gradient, with as little as 24% community similarity among contrasting sites. Species richness per plot increased asymptotically with foliar nitrogen concentrations of subalpine fir, demonstrating that many EMF species were well suited to soils with high rates of nitrogen mineralization. EMF species abundance in relation to site productivity included parabolic, negative linear, and positive exponential curves. Both multi-site and more narrowly distributed EMF were documented, and a diverse mix of mantle exploration types was present across the entire productivity gradient. The results demonstrate strong associations of EMF fungal species with edaphic characteristics, especially nitrogen availability, and a specialization in EMF communities that may contribute to the successful exploitation of such contrasting extremes in soil fertility by a single tree host.
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Affiliation(s)
- J M Kranabetter
- British Columbia Ministry of Forests and Range, 4300 North Road, Victoria, BC, Canada, V8Z 5J3.
| | - D M Durall
- University of British Columbia-Okanagan, 3333 University Way, Kelowna, BC, Canada, V1V 1V7
| | - W H MacKenzie
- British Columbia Ministry of Forests and Range, Bag 6000, Smithers, BC, Canada, V0J 2N0
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Abstract
The possible benefit of common mycorrhizal network linkages to seedling growth was tested in a low light partial-cut forest understory. Naturally regenerated western hemlock (Tsuga heterophylla Raf.) and hybrid spruce (Picea glauca × Picea sitchensis [Moench] Voss) seedlings were transplanted directly into soil or within bags of different pore sizes to restrict the amounts of root and ectomycorrhizal contact. The 5-year study included "full contact" (no bag), "moderate contact" (250-µm openings), and "low contact" (4-µm openings) treatments. Height increment was lowest for full contact seedlings over most of the experiment, and highest for low contact seedlings by years 4 and 5. Full contact seedlings also had slightly lower foliar N content than moderate and low contact seedlings. There were no significant interactions in growth detected between tree species and treatments, despite the higher potential for common mycorrhizal network linkages between a western hemlock understory and canopy. Fifty-eight ectomycorrhizal fungal morphotypes were identified on the seedlings, including many with smooth mantles or with only sparse emanating hyphae, which likely reduced the potential for common mycorrhizal network linkages. These results would support the more traditional concepts of competition for scarce resources by isolated seedlings as the primary interaction for the understory of these mature forests.Key words: common mycorrhizal networks, facilitation, shade tolerance, competition.
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Abstract
A diverse community of ectomycorrhizal (ECM) fungi is generally considered beneficial to forest ecosystems, but the function of ECM communities should be considered within an ecological context. The growth of hybrid spruce (Picea glauca (Moench) Voss × Picea sitchensis (Bong.) Carrière) seedlings was compared after transplanting into recent clearcuts, where soil moisture and nitrogen are typically readily available. The seedlings had either a "forest" ECM community (taken from forest gap edges) or a "pioneer" ECM community (taken from disturbed road edges) and were planted at wide and close spacing. After 3 years, morphotype distribution and abundance (64% community similarity between "forest" and "pioneer" seedlings) overlapped considerably, but height growth was 25% greater for the "pioneer" seedlings. There was a reduction in diameter at close spacing, with little difference in competition effects between ECM communities. There were no differences detected in foliar nitrogen concentrations and no evidence of nitrogen or phosphorus deficiencies. The advantage of fungi such as Amphinema byssoides, Thelephora terrestris, and Laccaria laccata might be the proliferation of fine roots that allows for the fullest utilization of abundant soil resources. The results suggest that the ECM communities arising after clearcut disturbances are well adapted to these initial soil conditions.Key words: ectomycorrhiza, disturbance, diversity, productivity, competition, Picea glauca.
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Kranabetter JM, Friesen J. Ectomycorrhizal community structure on western hemlock (Tsuga heterophylla) seedlings transplanted from forests into openings. ACTA ACUST UNITED AC 2002. [DOI: 10.1139/b02-071] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
This study tested whether mature-forest ectomycorrhizal (ECM) communities could be maintained in forest openings on seedlings. Naturally regenerated western hemlock (Tsuga heterophylla (Raf.) Sarg.) seedlings were transplanted from mature forests into openings and the ECM fungal community was compared after 2 years with similar seedlings planted back into the forests or seedlings from openings planted back into openings. Fewer ECM morphotypes, lower average richness per seedling, and a steeper, less even species distribution curve were found, all of which suggest that the mature-forest ECM fungal community changed after transplanting forest seedlings into the openings. The increased abundance of pioneer fungi such as Thelephora terresteris suggested that many of the mature-forest ECM fungi were unable to maintain or continue root colonization in openings. Results suggest that many mature-forest ECM fungi require further stand development to maintain enough rooting density and hyphal contact to persist.Key words: ectomycorrhizal succession, disturbance, species-importance curves, multistage and late-stage fungi.
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Abstract
Live trees within forest disturbances could support refugia populations of ectomycorrhizae fungi from which to reestablish ectomycorrhiza communities during forest succession. The effectiveness of refuge paper birch trees (Betula papyrifera Marsh.) in maintaining a forest ectomycorrhiza community on birch seedlings, both in clearcuts and forests, in northwest British Columbia was examined. Seedlings next to refuge birch trees in clearcuts had equal levels of average morphotype richness and eveness as seedlings next to mature birch trees in forests. Seedlings outside of the rooting zone of refuge trees had significantly less average morphotype richness in both clearcuts and forests, decreasing by 38 and 15%, respectively. The ectomycorrhiza communities were also more unique (lower community similarity) next to refuge trees than for seedlings away from refuge trees, especially in clearcuts. These treatment effects could be explained by differences in the ability to disperse and establish between early-stage, multi-stage, and late-stage ectomycorrhiza fungi. The results suggest refuge trees would be effective in forest management as sources of inocula for multi-stage and late-stage fungi.
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Kranabetter JM, Hayden S, Wright EF. A comparison of ectomycorrhiza communities from three conifer species planted on forest gap edges. ACTA ACUST UNITED AC 1999. [DOI: 10.1139/b99-109] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We examined the ectomycorrhiza communities on lodgepole pine (Pinus contorta var. latifolia Engelm), white spruce (Picea glauca (Moench) Voss), and subalpine fir (Abies lasiocarpa (Hook.) Nutt) seedlings planted together on mature-forest edges in northwestern British Columbia. We examined 32 seedlings of each tree species, grouped by pairs along the north and south edges of eight gaps. We found 74 morphotypes in total, with an average of 52 morphotypes per tree species. Morphotypes with emanating hyphae or strands made up 60% of the overall ectomycorrhiza community. Multihost fungi averaged almost 60% of total morphotypes in species comparisons, although some of the multihost fungi appeared to have tree host preferences. The average community similarity, based on morphotype abundance, was 52% between conifer species, and 37% for morphotypes with emanating hyphae or strands. Within planted groups, between seedlings 1-2 m apart, community similarity ranged from 2 to 40% for morphotypes with emanating hyphae or strands. In mature, mixed forests, the infrequent occurrence of many multihost ectomycorrhizae created a wide range in the probability of hyphal linkages between neighboring seedlings.Key words: ectomycorrhizae, community similarity, multiple host, host specificity, Pinus contorta, Picea glauca, Abies lasiocarpa
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Kranabetter JM, Wylie T. Ectomycorrhizal community structure across forest openings on naturally regenerated western hemlock seedlings. ACTA ACUST UNITED AC 1998. [DOI: 10.1139/b97-180] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We examined the diversity and distribution of ectomycorrhizal morphotypes on naturally regenerated western hemlock (Tsuga heterophylla (Raf.) Sarg.) seedlings across small forest openings (50-75 m in diameter) in northwest British Columbia. The total and average morphotype richness decreased across the 4-year-old forest openings despite the rapid establishment of western hemlock and lack of soil disturbance. Average fungal richness decreased from 13.1 morphotypes under the forest canopy to 9.6 at the forest edge (27% reduction) and to 7.8 in the forest opening (40% reduction). Cenococcum geophilum, Mycelium radicis atrovirens, and Lactarius I were the most abundant ectomycorrhizae at each gap position, and none of the ectomycorrhizal fungi found in openings were eliminated by "late-stage" fungi in mature stands. This fungal distribution supports the "multistage" concept of ectomycorrhizal succession. Seedlings under the forest canopy had a total of 38 fungal morphotypes in a relatively even distribution pattern that corresponded well to the "random niche boundary" hypothesis. Fungal distributions were progressively less even for seedlings at the forest edge and opening than for seedlings beneath the canopy, perhaps because reduced fungal diversity and hyphal inoculum had affected the competitive balance of the ectomycorrhizal community.Key words: ectomycorrhizal community, diversity, succession, forest gaps.
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