1
|
McPeek MA, Hicks Pries C. The complex circuitry of interactions determining coexistence among plants and mycorrhizal fungi. Ecology 2024; 105:e4281. [PMID: 38507266 DOI: 10.1002/ecy.4281] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/01/2023] [Revised: 12/05/2023] [Accepted: 02/01/2024] [Indexed: 03/22/2024]
Abstract
We present a mechanistic model of coexistence among a mycorrhizal fungus and one or two plant species that compete for a single nutrient. Plant-fungal coexistence is more likely if the fungus is better at extracting the environmental nutrient than the plant and the fungus acquires carbon from the plant above a minimum rate. When they coexist, their interaction can shift from mutualistic to parasitic at high nutrient availability. The fungus is a second nutrient source for plants and can promote the coexistence of two plant competitors if one is better at environmental nutrient extraction and the other is better at acquiring the nutrient from the fungus. Because it extracts carbon from both plants, the fungus also serves as a conduit of apparent competition between the plants. Consequently, the plant with the lower environmental nutrient extraction rate can drive the plant with the higher environmental nutrient extraction rate extinct at high carbon supply rates. This model illustrates mechanisms to explain several observed patterns, including shifts in plant-mycorrhizal growth responses and coexistence along nutrient gradients, equivocal results among experiments testing the effect of mycorrhizal fungi on plant diversity, and differences in plant diversity among ecosystems dominated by different mycorrhizal groups.
Collapse
Affiliation(s)
- Mark A McPeek
- Department of Biological Sciences, Dartmouth College, Hanover, New Hampshire, USA
| | - Caitlin Hicks Pries
- Department of Biological Sciences, Dartmouth College, Hanover, New Hampshire, USA
| |
Collapse
|
2
|
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. THE NEW PHYTOLOGIST 2024; 242:1603-1613. [PMID: 37771241 DOI: 10.1111/nph.19280] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [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.
Collapse
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
| |
Collapse
|
3
|
Brown AL, Pfab F, Baxter EC, Detmer AR, Moeller HV, Nisbet RM, Cunning R. Analysis of a mechanistic model of corals in association with multiple symbionts: within-host competition and recovery from bleaching. CONSERVATION PHYSIOLOGY 2022; 10:coac066. [PMID: 36247693 PMCID: PMC9558299 DOI: 10.1093/conphys/coac066] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/24/2021] [Revised: 07/25/2022] [Accepted: 09/09/2022] [Indexed: 06/14/2023]
Abstract
Coral reefs are increasingly experiencing stressful conditions, such as high temperatures, that cause corals to undergo bleaching, a process where they lose their photosynthetic algal symbionts. Bleaching threatens both corals' survival and the health of the reef ecosystems they create. One possible mechanism for corals to resist bleaching is through association with stress-tolerant symbionts, which are resistant to bleaching but may be worse partners in mild conditions. Some corals have been found to associate with multiple symbiont species simultaneously, which potentially gives them access to the benefits of both stress-sensitive and -tolerant symbionts. However, within-host competition between symbionts may lead to competitive exclusion of one partner, and the consequences of associating with multiple partners simultaneously are not well understood. We modify a mechanistic model of coral-algal symbiosis to investigate the effect of environmental conditions on within-host competitive dynamics between stress-sensitive and -tolerant symbionts and the effect of access to a tolerant symbiont on the dynamics of recovery from bleaching. We found that the addition of a tolerant symbiont can increase host survival and recovery from bleaching in high-light conditions. Competitive exclusion of the tolerant symbiont occurred slowly at intermediate light levels. Interestingly, there were some cases of post-bleaching competitive exclusion after the tolerant symbiont had helped the host recover.
Collapse
Affiliation(s)
- Alexandra Lynne Brown
- Corresponding author: Department of Ecology, Evolution, and Marine Biology, University of California, Santa Barbara, Santa Barbara, CA 93106, USA. E-mail:
| | - Ferdinand Pfab
- Department of Ecology, Evolution, and Marine Biology, University of California, Santa Barbara, Santa Barbara, CA 93106, USA
| | - Ethan C Baxter
- Department of Ecology, Evolution, and Marine Biology, University of California, Santa Barbara, Santa Barbara, CA 93106, USA
| | - A Raine Detmer
- Department of Ecology, Evolution, and Marine Biology, University of California, Santa Barbara, Santa Barbara, CA 93106, USA
| | - Holly V Moeller
- Department of Ecology, Evolution, and Marine Biology, University of California, Santa Barbara, Santa Barbara, CA 93106, USA
| | - Roger M Nisbet
- Department of Ecology, Evolution, and Marine Biology, University of California, Santa Barbara, Santa Barbara, CA 93106, USA
| | - Ross Cunning
- Daniel P. Haerther Center for Conservation and Research, John G. Shedd Aquarium, Chicago, IL 60605, USA
| |
Collapse
|
4
|
Bogar LM, Tavasieff OS, Raab TK, Peay KG. Does resource exchange in ectomycorrhizal symbiosis vary with competitive context and nitrogen addition? THE NEW PHYTOLOGIST 2022; 233:1331-1344. [PMID: 34797927 DOI: 10.1111/nph.17871] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/24/2020] [Accepted: 11/14/2021] [Indexed: 06/13/2023]
Abstract
Ectomycorrhizal symbiosis is essential for the nutrition of most temperate forest trees and helps regulate the movement of carbon (C) and nitrogen (N) through forested ecosystems. The factors governing the exchange of plant C for fungal N, however, remain obscure. Because competition and soil resources may influence ectomycorrhizal resource movement, we performed a 10-month split-root microcosm study using Pinus muricata seedlings with Thelephora terrestris, Suillus pungens, or no ectomycorrhizal fungus, under two N concentrations in artificial soil. Fungi competed directly with roots and indirectly with each other. We used stable isotope enrichment to track plant photosynthate and fungal N. For T. terrestris, plants received N commensurate with the C given to their fungal partners. Thelephora terrestris was a superior mutualist under high-N conditions. For S. pungens, plant C and fungal N exchange were not coupled. However, in low-N conditions, plants preferentially allocated C to S. pungens rather than T. terrestris. Our results suggest that ectomycorrhizal resource transfer depends on competitive and nutritional context. Plants can exchange C for fungal N, but coupling of these resources can depend on the fungal species and soil N. Understanding the diversity of fungal strategies, and how they change with environmental context, reveals mechanisms driving this important symbiosis.
Collapse
Affiliation(s)
- Laura M Bogar
- Department of Ecology, Evolution, and Marine Biology, University of California, Santa Barbara, Santa Barbara, CA, 93106, USA
| | - Oceana S Tavasieff
- Department of Ecology, Evolution, and Marine Biology, University of California, Santa Barbara, Santa Barbara, CA, 93106, USA
| | - Ted K Raab
- Department of Global Ecology, Carnegie Institution for Science, Stanford, CA, 94305, USA
| | - Kabir G Peay
- Department of Biology, Stanford University, Stanford, CA, 94305, USA
- Woods Institute for the Environment, Stanford University, Stanford, CA, 94305, USA
| |
Collapse
|
5
|
Ghosh S, Reuman D, Bever JD. Preferential allocation of benefits and resource competition among recipients allows coexistence of symbionts within hosts. Am Nat 2021; 199:468-479. [DOI: 10.1086/718643] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
|
6
|
Germain SJ, Lutz JA. Shared friends counterbalance shared enemies in old forests. Ecology 2021; 102:e03495. [PMID: 34309021 DOI: 10.1002/ecy.3495] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Revised: 05/17/2021] [Accepted: 05/26/2021] [Indexed: 11/09/2022]
Abstract
Mycorrhizal mutualisms are nearly ubiquitous across plant communities. Yet, it is still unknown whether facilitation among plants arises primarily from these mycorrhizal networks or from physical and ecological attributes of plants themselves. Here, we tested the relative contributions of mycorrhizae and plants to both positive and negative biotic interactions to determine whether plant-soil feedbacks with mycorrhizae neutralize competition and enemies within multitrophic forest community networks. We used Bayesian hierarchical generalized linear modeling to examine mycorrhizal-guild-specific and mortality-cause-specific woody plant survival compiled from a spatially and temporally explicit data set comprising 101,096 woody plants from three mixed-conifer forests across western North America. We found positive plant-soil feedbacks for large-diameter trees: species-rich woody plant communities indirectly promoted large tree survival when connected via mycorrhizal networks. Shared mycorrhizae primarily counterbalanced apparent competition mediated by tree enemies (e.g., bark beetles, soil pathogens) rather than diffuse competition between plants. We did not find the same survival benefits for small trees or shrubs. Our findings suggest that lower large-diameter tree mortality susceptibility in species-rich temperate forests resulted from greater access to shared mycorrhizal networks. The interrelated importance of aboveground and belowground biodiversity to large tree survival may be critical for counteracting increasing pathogen, bark beetle, and density threats.
Collapse
Affiliation(s)
- Sara J Germain
- Department of Wildland Resources, Utah State University, Logan, Utah, 84322-5230, USA
| | - James A Lutz
- Department of Wildland Resources, Utah State University, Logan, Utah, 84322-5230, USA
| |
Collapse
|
7
|
Symbiotic niche mapping reveals functional specialization by two ectomycorrhizal fungi that expands the host plant niche. FUNGAL ECOL 2020. [DOI: 10.1016/j.funeco.2020.100960] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
|
8
|
Martignoni MM, Hart MM, Garnier J, Tyson RC. Parasitism within mutualist guilds explains the maintenance of diversity in multi-species mutualisms. THEOR ECOL-NETH 2020. [DOI: 10.1007/s12080-020-00472-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
9
|
Bachelot B, Lee CT. Disturbances Can Promote and Hinder Coexistence of Competitors in Ongoing Partner Choice Mutualisms. Am Nat 2020; 195:445-462. [DOI: 10.1086/707258] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
|
10
|
Song C, Von Ahn S, Rohr RP, Saavedra S. Towards a Probabilistic Understanding About the Context-Dependency of Species Interactions. Trends Ecol Evol 2020; 35:384-396. [PMID: 32007296 DOI: 10.1016/j.tree.2019.12.011] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2019] [Revised: 12/11/2019] [Accepted: 12/20/2019] [Indexed: 01/10/2023]
Abstract
Observational and experimental studies have shown that an interaction class between two species (be it mutualistic, competitive, antagonistic, or neutral) may switch to a different class, depending on the biotic and abiotic factors within which species are observed. This complexity arising from the evidence of context-dependencies has underscored a difficulty in establishing a systematic analysis about the extent to which species interactions are expected to switch in nature and experiments. Here, we propose an overarching theoretical framework, by integrating probabilistic and structural approaches, to establish null expectations about switches of interaction classes across environmental contexts. This integration provides a systematic platform upon which it is possible to establish new hypotheses, clear predictions, and quantifiable expectations about the context-dependency of species interactions.
Collapse
Affiliation(s)
- Chuliang Song
- Department of Civil and Environmental Engineering, MIT, 77 Massachusetts Av., Cambridge 02139, MA, USA
| | - Sarah Von Ahn
- Department of Mathematics, MIT, 77 Massachusetts Av., Cambridge 02139, MA, USA
| | - Rudolf P Rohr
- Department of Biology - Ecology and Evolution, University of Fribourg Chemin du Musée 10, Fribourg CH-1700, Switzerland
| | - Serguei Saavedra
- Department of Civil and Environmental Engineering, MIT, 77 Massachusetts Av., Cambridge 02139, MA, USA.
| |
Collapse
|
11
|
Karl JP, Barbato RA, Doherty LA, Gautam A, Glaven SM, Kokoska RJ, Leary D, Mickol RL, Perisin MA, Hoisington AJ, Van Opstal EJ, Varaljay V, Kelley-Loughnane N, Mauzy CA, Goodson MS, Soares JW. Meeting report of the third annual Tri-Service Microbiome Consortium symposium. ENVIRONMENTAL MICROBIOME 2020; 15:12. [PMID: 32835172 PMCID: PMC7356122 DOI: 10.1186/s40793-020-00359-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Accepted: 06/30/2020] [Indexed: 05/05/2023]
Abstract
The Tri-Service Microbiome Consortium (TSMC) was founded to enhance collaboration, coordination, and communication of microbiome research among U.S. Department of Defense (DoD) organizations and to facilitate resource, material and information sharing among consortium members. The 2019 annual symposium was held 22-24 October 2019 at Wright-Patterson Air Force Base in Dayton, OH. Presentations and discussions centered on microbiome-related topics within five broad thematic areas: 1) human microbiomes; 2) transitioning products into Warfighter solutions; 3) environmental microbiomes; 4) engineering microbiomes; and 5) microbiome simulation and characterization. Collectively, the symposium provided an update on the scope of current DoD microbiome research efforts, highlighted innovative research being done in academia and industry that can be leveraged by the DoD, and fostered collaborative opportunities. This report summarizes the presentations and outcomes of the 3rd annual TSMC symposium.
Collapse
Affiliation(s)
- J. Philip Karl
- Military Nutrition Division, United States Army Research Institute of Environmental Medicine, Natick, MA USA
| | - Robyn A. Barbato
- United States Army Cold Regions Research and Engineering Laboratory, Hanover, NH USA
| | - Laurel A. Doherty
- Soldier Performance Optimization Directorate, United States Army Combat Capabilities Development Command Soldier Center, Natick, MA USA
| | - Aarti Gautam
- Medical Readiness Systems Biology, Center for Military Psychiatry and Neuroscience, Walter Reed Army Institute of Research, Silver Spring, MD USA
| | - Sarah M. Glaven
- Center for Bio/Molecular Science and Engineering, Naval Research Laboratory, Washington, DC USA
| | - Robert J. Kokoska
- Physical Sciences Directorate, United States Army Research Laboratory – United States Army Research Office, Research Triangle Park, Durham, NC USA
| | - Dagmar Leary
- Center for Biomolecular Science & Engineering, United States Naval Research Laboratory, Washington, DC USA
| | | | - Matthew A. Perisin
- Biotechnology Branch, United States Army Combat Capabilities Development Command-Army Research Laboratory, Adelphi, MD USA
| | - Andrew J. Hoisington
- Department of Systems Engineering and Management, Air Force Institute of Technology, Wright-Patterson AFB, Dayton, OH USA
- Military and Veteran Microbiome: Consortium for Research and Education, Aurora, CO USA
- Veterans Health Administration, Rocky Mountain Mental Illness Research Education and Clinical Center, Rocky Mountain Regional Veterans Affairs Medical Center, Aurora, CO USA
- Department of Physical Medicine & Rehabilitation and Center for Neuroscience, University of Colorado Anschutz Medical Campus, Aurora, CO USA
| | - Edward J. Van Opstal
- Human Systems Directorate, Office of the Underscretary of Defense for Research & Engineering, Washington, DC USA
| | - Vanessa Varaljay
- Soft Matter Materials Branch, Materials and Manufacturing Directorate, Air Force Research Laboratory, Wright-Patterson AFB, Dayton, OH USA
| | - Nancy Kelley-Loughnane
- Soft Matter Materials Branch, Materials and Manufacturing Directorate, Air Force Research Laboratory, Wright-Patterson AFB, Dayton, OH USA
| | - Camilla A. Mauzy
- 711th Human Performance Wing, Air Force Research Laboratory, Wright-Patterson AFB, Dayton, OH USA
| | - Michael S. Goodson
- 711th Human Performance Wing, Air Force Research Laboratory, Wright-Patterson AFB, Dayton, OH USA
| | - Jason W. Soares
- Soldier Performance Optimization Directorate, United States Army Combat Capabilities Development Command Soldier Center, Natick, MA USA
| |
Collapse
|
12
|
Bogar L, Peay K, Kornfeld A, Huggins J, Hortal S, Anderson I, Kennedy P. Plant-mediated partner discrimination in ectomycorrhizal mutualisms. MYCORRHIZA 2019; 29:97-111. [PMID: 30617861 DOI: 10.1007/s00572-018-00879-7] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/07/2018] [Accepted: 12/26/2018] [Indexed: 05/22/2023]
Abstract
Although ectomycorrhizal fungi have well-recognized effects on ecological processes ranging from plant community dynamics to carbon cycling rates, it is unclear if plants are able to actively influence the structure of these fungal communities. To address this knowledge gap, we performed two complementary experiments to determine (1) whether ectomycorrhizal plants can discriminate among potential fungal partners, and (2) to what extent the plants might reward better mutualists. In experiment 1, split-root Larix occidentalis seedlings were inoculated with spores from three Suillus species (S. clintonianus, S. grisellus, and S. spectabilis). In experiment 2, we manipulated the symbiotic quality of Suillus brevipes isolates on split-root Pinus muricata seedlings by changing the nitrogen resources available, and used carbon-13 labeling to track host investment in fungi. In experiment 1, we found that hosts can discriminate in multi-species settings. The split-root seedlings inhibited colonization by S. spectabilis whenever another fungus was available, despite similar benefits from all three fungi. In experiment 2, we found that roots and fungi with greater nitrogen supplies received more plant carbon. Our results suggest that plants may be able to regulate this symbiosis at a relatively fine scale, and that this regulation can be integrated across spatially separated portions of a root system.
Collapse
Affiliation(s)
- Laura Bogar
- Department of Biology, Stanford University, 371 Serra Mall, Stanford, CA, 94305, USA.
| | - Kabir Peay
- Department of Biology, Stanford University, 371 Serra Mall, Stanford, CA, 94305, USA
| | - Ari Kornfeld
- Department of Global Ecology, Carnegie Institution for Science, Stanford, CA, 94305, USA
| | - Julia Huggins
- Department of Plant & Microbial Biology, University of Minnesota, Saint Paul, MN, 55108, USA
| | - Sara Hortal
- Hawkesbury Institute for the Environment, Western Sydney University, Hawkesbury Campus, Locked Bag 1797, Penrith, NSW, 2751, Australia
| | - Ian Anderson
- Hawkesbury Institute for the Environment, Western Sydney University, Hawkesbury Campus, Locked Bag 1797, Penrith, NSW, 2751, Australia
| | - Peter Kennedy
- Department of Plant & Microbial Biology, University of Minnesota, Saint Paul, MN, 55108, USA
| |
Collapse
|
13
|
Christian N, Bever JD. Carbon allocation and competition maintain variation in plant root mutualisms. Ecol Evol 2018; 8:5792-5800. [PMID: 29938093 PMCID: PMC6010867 DOI: 10.1002/ece3.4118] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2017] [Revised: 02/02/2018] [Accepted: 03/29/2018] [Indexed: 12/20/2022] Open
Abstract
Plants engage in multiple root symbioses that offer varying degrees of benefit. We asked how variation in partner quality persists using a resource-ratio model of population growth. We considered the plant's ability to preferentially allocate carbon to mutualists and competition for plant carbon between mutualist and nonmutualist symbionts. We treated carbon as two nutritionally interchangeable, but temporally separated, resources-carbon allocated indiscriminately for the construction of the symbiosis, and carbon preferentially allocated to the mutualist after symbiosis establishment and assessment. This approach demonstrated that coexistence of mutualists and nonmutualists is possible when fidelity of the plant to the mutualist and the cost of mutualism mediate resource competition. Furthermore, it allowed us to trace symbiont population dynamics given varying degrees of carbon allocation. Specifically, coexistence occurs at intermediate levels of preferential allocation. Our findings are consistent with previous empirical studies as well the application of biological market theory to plantroot symbioses.
Collapse
Affiliation(s)
- Natalie Christian
- Evolution, Ecology and Behavior ProgramDepartment of BiologyIndiana UniversityBloomingtonIndiana
| | - James D. Bever
- Department of Ecology and Evolutionary BiologyThe University of KansasLawrenceKansas
| |
Collapse
|
14
|
Tylianakis JM, Martínez-García LB, Richardson SJ, Peltzer DA, Dickie IA. Symmetric assembly and disassembly processes in an ecological network. Ecol Lett 2018; 21:896-904. [PMID: 29611321 DOI: 10.1111/ele.12957] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2018] [Revised: 02/24/2018] [Accepted: 03/02/2018] [Indexed: 02/03/2023]
Abstract
The processes whereby ecological networks emerge, persist and decay throughout ecosystem development are largely unknown. Here we study networks of plant and arbuscular mycorrhizal fungal (AMF) communities along a 120 000 year soil chronosequence, as they undergo assembly (progression) and then disassembly (retrogression). We found that network assembly and disassembly were symmetrical, self-reinforcing processes that together were capable of generating key attributes of network architecture. Plant and AMF species that had short indirect paths to others in the community (i.e. high centrality), rather than many direct interaction partners (i.e. high degree), were best able to attract new interaction partners and, in the case of AMF species, also to retain existing interactions with plants during retrogression. We then show using simulations that these non-random patterns of attachment and detachment promote nestedness of the network. These results have implications for predicting extinction sequences, identifying focal points for invasions and suggesting trajectories for restoration.
Collapse
Affiliation(s)
- Jason M Tylianakis
- Centre for Integrative Ecology, School of Biological Sciences, University of Canterbury, Private Bag 4800, Christchurch, 8140, New Zealand.,Department of Life Sciences, Imperial College London, Silwood Park Campus, Buckhurst Road, Ascot, Berkshire, SL5 7PY, UK.,Bio-protection Research Centre, School of Biological Sciences, University of Canterbury, Private Bag 4800, Christchurch, 8140, New Zealand
| | - Laura B Martínez-García
- Landcare Research, PO Box 69040, Lincoln, 7640, New Zealand.,Department of Soil Quality, Wageningen University, P.O. Box 47, Wageningen, 6700 AA, The Netherlands
| | | | | | - Ian A Dickie
- Bio-protection Research Centre, School of Biological Sciences, University of Canterbury, Private Bag 4800, Christchurch, 8140, New Zealand
| |
Collapse
|
15
|
Batstone RT, Carscadden KA, Afkhami ME, Frederickson ME. Using niche breadth theory to explain generalization in mutualisms. Ecology 2018; 99:1039-1050. [PMID: 29453827 DOI: 10.1002/ecy.2188] [Citation(s) in RCA: 50] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/01/2017] [Revised: 12/12/2017] [Accepted: 01/22/2018] [Indexed: 02/02/2023]
Abstract
For a mutualism to remain evolutionarily stable, theory predicts that mutualists should limit their associations to high-quality partners. However, most mutualists either simultaneously or sequentially associate with multiple partners that confer the same type of reward. By viewing mutualisms through the lens of niche breadth evolution, we outline how the environment shapes partner availability and relative quality, and ultimately a focal mutualist's partner breadth. We argue that mutualists that associate with multiple partners may have a selective advantage compared to specialists for many reasons, including sampling, complementarity, and portfolio effects, as well as the possibility that broad partner breadth increases breadth along other niche axes. Furthermore, selection for narrow partner breadth is unlikely to be strong when the environment erodes variation in partner quality, reduces the costs of interacting with low-quality partners, spatially structures partner communities, or decreases the strength of mutualism. Thus, we should not be surprised that most mutualists have broad partner breadth, even if it allows for ineffective partners to persist.
Collapse
Affiliation(s)
- Rebecca T Batstone
- Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, Ontario, M5S 3B2, Canada
| | - Kelly A Carscadden
- Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, Ontario, M5S 3B2, Canada.,Department of Ecology and Evolutionary Biology, University of Colorado Boulder, Boulder, Colorado, 80309, USA
| | - Michelle E Afkhami
- Department of Biology, University of Miami, Coral Gables, Florida, 33146, USA
| | - Megan E Frederickson
- Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, Ontario, M5S 3B2, Canada
| |
Collapse
|
16
|
Bachelot B, Lee CT. Dynamic preferential allocation to arbuscular mycorrhizal fungi explains fungal succession and coexistence. Ecology 2017; 99:372-384. [PMID: 29121390 DOI: 10.1002/ecy.2080] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/01/2017] [Revised: 10/11/2017] [Accepted: 10/23/2017] [Indexed: 11/12/2022]
Abstract
Evidence accumulates about the role of arbuscular mycorrhizal (AM) fungi in shaping plant communities, but little is known about the factors determining the biomass and coexistence of several types of AM fungi in a plant community. Here, using a consumer-resource framework that treats the relationship between plants and fungi as simultaneous, reciprocal exploitation, we investigated what patterns of dynamic preferential plant carbon allocation to empirically-defined fungal types (on-going partner choice) would be optimal for plants, and how these patterns depend on successional dynamics. We found that ruderal AM fungi can dominate under low steady-state nutrient availability, and competitor AM fungi can dominate at higher steady-state nutrient availability; these are conditions characteristic of early and late succession, respectively. We also found that dynamic preferential allocation alone can maintain a diversity of mutualists, suggesting that on-going partner choice is a new coexistence mechanism for mutualists. Our model can therefore explain both mutualist coexistence and successional strategy, providing a powerful tool to derive testable predictions.
Collapse
Affiliation(s)
- Benedicte Bachelot
- Department of BioSciences, Rice University, 6100 Main Street, Houston, Texas, 77096, USA
| | - Charlotte T Lee
- Department of Biology, Duke University, 130 Science Drive, Durham, North Carolina, 27708, USA
| |
Collapse
|
17
|
Clark TJ, Friel CA, Grman E, Shachar‐Hill Y, Friesen ML. Modelling nutritional mutualisms: challenges and opportunities for data integration. Ecol Lett 2017; 20:1203-1215. [DOI: 10.1111/ele.12810] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2016] [Revised: 08/23/2016] [Accepted: 06/12/2017] [Indexed: 01/09/2023]
Affiliation(s)
- Teresa J. Clark
- Department of Plant Biology Michigan State University 612 Wilson Rd. East Lansing MI48824 USA
| | - Colleen A. Friel
- Department of Plant Biology Michigan State University 612 Wilson Rd. East Lansing MI48824 USA
| | - Emily Grman
- Biology Department Eastern Michigan University 441 Mark Jefferson Science Complex Ypsilanti MI48197 USA
| | - Yair Shachar‐Hill
- Department of Plant Biology Michigan State University 612 Wilson Rd. East Lansing MI48824 USA
| | - Maren L. Friesen
- Department of Plant Biology Michigan State University 612 Wilson Rd. East Lansing MI48824 USA
| |
Collapse
|
18
|
|
19
|
|
20
|
Peay KG. The Mutualistic Niche: Mycorrhizal Symbiosis and Community Dynamics. ANNUAL REVIEW OF ECOLOGY EVOLUTION AND SYSTEMATICS 2016. [DOI: 10.1146/annurev-ecolsys-121415-032100] [Citation(s) in RCA: 83] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The niche is generally viewed in terms of species' intrinsic physiological potential and limitations due to competition. Although DNA sequencing has revealed the ubiquity of beneficial microbial symbioses, the role of mutualisms in shaping species niches is not broadly recognized. In this review, I use a widespread terrestrial mutualism, the ectomycorrhizal symbiosis, to help develop the mutualistic niche concept. Using contemporary niche theory, I show how mycorrhizal symbioses expand environmental ranges (requirement niche) and influence resource use (impact niche) for both plants and fungi. Simple niche models for competition between resource specialists and generalists also predict a range of ecological phenomena, from unexpected monodominance by some tropical trees to the functional biogeography of mycorrhizal symbiosis. A niche-based view of mutualism may also help explain stability of mutualisms even in the absence of clear benefits. The niche is a central concept in ecology, and better integration of mutualism will more accurately reflect the positive interactions experienced by nearly all species.
Collapse
Affiliation(s)
- Kabir G. Peay
- Department of Biology, Stanford University, Stanford, California 94122
| |
Collapse
|