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Netherway T, Bengtsson J, Buegger F, Fritscher J, Oja J, Pritsch K, Hildebrand F, Krab EJ, Bahram M. Pervasive associations between dark septate endophytic fungi with tree root and soil microbiomes across Europe. Nat Commun 2024; 15:159. [PMID: 38167673 PMCID: PMC10761831 DOI: 10.1038/s41467-023-44172-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2022] [Accepted: 12/04/2023] [Indexed: 01/05/2024] Open
Abstract
Trees interact with a multitude of microbes through their roots and root symbionts such as mycorrhizal fungi and root endophytes. Here, we explore the role of fungal root symbionts as predictors of the soil and root-associated microbiomes of widespread broad-leaved trees across a European latitudinal gradient. Our results suggest that, alongside factors such as climate, soil, and vegetation properties, root colonization by ectomycorrhizal, arbuscular mycorrhizal, and dark septate endophytic fungi also shapes tree-associated microbiomes. Notably, the structure of root and soil microbiomes across our sites is more strongly and consistently associated with dark septate endophyte colonization than with mycorrhizal colonization and many abiotic factors. Root colonization by dark septate endophytes also has a consistent negative association with the relative abundance and diversity of nutrient cycling genes. Our study not only indicates that root-symbiotic interactions are an important factor structuring soil communities and functions in forest ecosystems, but also that the hitherto less studied dark septate endophytes are likely to be central players in these interactions.
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Affiliation(s)
- Tarquin Netherway
- Department of Ecology, Swedish University of Agricultural Sciences, Ulls väg 16, 756 51, Uppsala, Sweden.
| | - Jan Bengtsson
- Department of Ecology, Swedish University of Agricultural Sciences, Ulls väg 16, 756 51, Uppsala, Sweden
| | - Franz Buegger
- Research Unit for Environmental Simulation (EUS), German Research Center for Environmental Health, Helmholtz Zentrum München, Ingolstaedter Landstr. 1, 85764, Neuherberg, Germany
| | - Joachim Fritscher
- Quadram Institute Bioscience, Norwich Research Park, Norwich, Norfolk, NR4 7UQ, UK
- Digital Biology, Earlham Institute, Norwich Research Park, Norwich, Norfolk, NR4 7UQ, UK
| | - Jane Oja
- Department of Botany, Institute of Ecology and Earth Sciences, University of Tartu, 40 Lai St, Tartu, Estonia
| | - Karin Pritsch
- Research Unit for Environmental Simulation (EUS), German Research Center for Environmental Health, Helmholtz Zentrum München, Ingolstaedter Landstr. 1, 85764, Neuherberg, Germany
| | - Falk Hildebrand
- Quadram Institute Bioscience, Norwich Research Park, Norwich, Norfolk, NR4 7UQ, UK
- Digital Biology, Earlham Institute, Norwich Research Park, Norwich, Norfolk, NR4 7UQ, UK
| | - Eveline J Krab
- Department of Soil and Environment, Swedish University of Agricultural Sciences, Lennart Hjelms väg 9, 750 07, Uppsala, Sweden
| | - Mohammad Bahram
- Department of Ecology, Swedish University of Agricultural Sciences, Ulls väg 16, 756 51, Uppsala, Sweden
- Department of Botany, Institute of Ecology and Earth Sciences, University of Tartu, 40 Lai St, Tartu, Estonia
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Qi S, Wang J, Wan L, Dai Z, da Silva Matos DM, Du D, Egan S, Bonser SP, Thomas T, Moles AT. Arbuscular Mycorrhizal Fungi Contribute to Phosphorous Uptake and Allocation Strategies of Solidago canadensis in a Phosphorous-Deficient Environment. FRONTIERS IN PLANT SCIENCE 2022; 13:831654. [PMID: 35401639 PMCID: PMC8987128 DOI: 10.3389/fpls.2022.831654] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2021] [Accepted: 02/21/2022] [Indexed: 05/17/2023]
Abstract
Arbuscular mycorrhizal fungi (AMF) can facilitate the uptake of limiting or inaccessible nutrients by plants. However, the importance of AMF for invasive plants under phosphorus (P) limitation is poorly well understood because of the presence of non-focal microorganisms, such as endophytes or rhizosphere bacteria. In this study, we investigated how an invasive clonal plant Solidago canadensis benefits from the AMF Glomus intraradices by using a completely sterile culturing system, which is composed of aseptic seedlings, a pure AMF strain, and a sterile growth environment. We found that the colonization rate, abundance, and spore production of AMF in the insoluble P treatment was more than twice as much as in the available P treatment. Plant above-ground growth was enhanced almost 50% by AMF in the insoluble P treatment. Importantly, AMF were able to facilitate P acquisition by the plant in insoluble P conditions, allowing plants to have lower investment into below-ground biomass and higher benefit/return for above-ground biomass. This study demonstrated the important contribution that AMF make to plants in phosphate-deficient environments eliminating interference from non-focal microorganisms. Our results also suggest that interaction with AMF could contribute to the invasiveness of clonal plant S. canadensis in a resource-deficient environment.
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Affiliation(s)
- Shanshan Qi
- Key Laboratory of Modern Agricultural Equipment and Technology, Ministry of Education, School of Agricultural Engineering, Jiangsu University, Zhenjiang, China
- School of the Environment Safety Engineering, Jiangsu University, Zhenjiang, China
- Evolution & Ecology Research Centre, School of Biological, Earth and Environmental Sciences, UNSW Sydney, Sydney, NSW, Australia
| | - Jiahao Wang
- Key Laboratory of Modern Agricultural Equipment and Technology, Ministry of Education, School of Agricultural Engineering, Jiangsu University, Zhenjiang, China
| | - Lingyun Wan
- Guangxi Botanical Garden of Medicinal Plants, Nanning, China
| | - Zhicong Dai
- School of the Environment Safety Engineering, Jiangsu University, Zhenjiang, China
- Centre for Marine Science and Innovation, School of Biological, Earth and Environmental Sciences, UNSW Sydney, Sydney, NSW, Australia
- Jiangsu Collaborative Innovation Center of Technology and Material of Water Treatment, Suzhou University of Science and Technology, Suzhou, China
| | | | - Daolin Du
- School of the Environment Safety Engineering, Jiangsu University, Zhenjiang, China
| | - Suhelen Egan
- Centre for Marine Science and Innovation, School of Biological, Earth and Environmental Sciences, UNSW Sydney, Sydney, NSW, Australia
| | - Stephen P. Bonser
- Evolution & Ecology Research Centre, School of Biological, Earth and Environmental Sciences, UNSW Sydney, Sydney, NSW, Australia
| | - Torsten Thomas
- Centre for Marine Science and Innovation, School of Biological, Earth and Environmental Sciences, UNSW Sydney, Sydney, NSW, Australia
| | - Angela T. Moles
- Evolution & Ecology Research Centre, School of Biological, Earth and Environmental Sciences, UNSW Sydney, Sydney, NSW, Australia
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Fast-decaying plant litter enhances soil carbon in temperate forests but not through microbial physiological traits. Nat Commun 2022; 13:1229. [PMID: 35264580 PMCID: PMC8907208 DOI: 10.1038/s41467-022-28715-9] [Citation(s) in RCA: 28] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2021] [Accepted: 01/28/2022] [Indexed: 01/13/2023] Open
Abstract
Conceptual and empirical advances in soil biogeochemistry have challenged long-held assumptions about the role of soil micro-organisms in soil organic carbon (SOC) dynamics; yet, rigorous tests of emerging concepts remain sparse. Recent hypotheses suggest that microbial necromass production links plant inputs to SOC accumulation, with high-quality (i.e., rapidly decomposing) plant litter promoting microbial carbon use efficiency, growth, and turnover leading to more mineral stabilization of necromass. We test this hypothesis experimentally and with observations across six eastern US forests, using stable isotopes to measure microbial traits and SOC dynamics. Here we show, in both studies, that microbial growth, efficiency, and turnover are negatively (not positively) related to mineral-associated SOC. In the experiment, stimulation of microbial growth by high-quality litter enhances SOC decomposition, offsetting the positive effect of litter quality on SOC stabilization. We suggest that microbial necromass production is not the primary driver of SOC persistence in temperate forests. Factors such as microbial necromass origin, alternative SOC formation pathways, priming effects, and soil abiotic properties can strongly decouple microbial growth, efficiency, and turnover from mineral-associated SOC. Mineral-associated soil carbon buildup is poorly explained by microbial necromass production (a common hypothesis). During litter decomposition, these processes are decoupled by priming effects and alternate soil carbon formation pathways
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4
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Qin F, Yu S. Compatible Mycorrhizal Types Contribute to a Better Design for Mixed Eucalyptus Plantations. FRONTIERS IN PLANT SCIENCE 2021; 12:616726. [PMID: 33643349 PMCID: PMC7907608 DOI: 10.3389/fpls.2021.616726] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/13/2020] [Accepted: 01/06/2021] [Indexed: 06/12/2023]
Abstract
Mixed-species forest plantation is a sound option to facilitate ecological restoration, plant diversity and ecosystem functions. Compatible species combinations are conducive to reconstruct plant communities that can persist at a low cost without further management and even develop into natural forest communities. However, our understanding of how the compatibility of mycorrhizal types mediates species coexistence is still limited, especially in a novel agroforestry system. Here, we assessed the effects of mycorrhizal association type on the survival and growth of native woody species in mixed-species Eucalyptus plantations. To uncover how mycorrhizal type regulates plant-soil feedbacks, we first conducted a pot experiments by treating distinct mycorrhizal plants with soil microbes from their own or other mycorrhizal types. We then compared the growth response of arbuscular mycorrhizal plants and ectomycorrhizal plants to different soil microbial compositions associated with Eucalyptus plants. We found that the type of mycorrhizal association had a significant impact on the survival and growth of native tree species in the Eucalyptus plantations. The strength and direction of the plant-soil feedbacks of focal tree species depended on mycorrhizal type. Non-mycorrhizal plants had consistent negative feedbacks with the highest survival in the Eucalyptus plantations, whereas nitrogen-fixing plants had consistent positive feedbacks and the lowest survival. Arbuscular mycorrhizal and ectomycorrhizal plants performed varied feedback responses to soil microbes from distinct mycorrhizal plant species. Non-mycorrhizal plants grew better with Eucalyptus soil microbes while nitrogen-fixing plants grew worse with their own conspecific soil microbes. Different soil microbial compositions of Eucalyptus consistently increased the aboveground growth of arbuscular mycorrhizal plants, but the non-mycorrhizal microbial composition of the Eucalyptus soil resulted in greater belowground growth of ectomycorrhizal plants. Overall, Eucalyptus plants induced an unfavorable soil community, impeding coexistence with other mycorrhizal plants. Our study provides consistent observational and experimental evidence that mycorrhizal-mediated plant-microbial feedback on species coexistence among woody species. These findings are with important implications to optimize the species combinations for better design of mixed forest plantations.
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Tatsumi C, Hyodo F, Taniguchi T, Shi W, Koba K, Fukushima K, Du S, Yamanaka N, Templer P, Tateno R. Arbuscular Mycorrhizal Community in Roots and Nitrogen Uptake Patterns of Understory Trees Beneath Ectomycorrhizal and Non-ectomycorrhizal Overstory Trees. FRONTIERS IN PLANT SCIENCE 2021; 11:583585. [PMID: 33519844 PMCID: PMC7840530 DOI: 10.3389/fpls.2020.583585] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/21/2020] [Accepted: 12/07/2020] [Indexed: 06/12/2023]
Abstract
Nitrogen (N) is an essential plant nutrient, and plants can take up N from several sources, including via mycorrhizal fungal associations. The N uptake patterns of understory plants may vary beneath different types of overstory trees, especially through the difference in their type of mycorrhizal association (arbuscular mycorrhizal, AM; or ectomycorrhizal, ECM), because soil mycorrhizal community and N availability differ beneath AM (non-ECM) and ECM overstory trees (e.g., relatively low nitrate content beneath ECM overstory trees). To test this hypothesis, we examined six co-existing AM-symbiotic understory tree species common beneath both AM-symbiotic black locust (non-ECM) and ECM-symbiotic oak trees of dryland forests in China. We measured AM fungal community composition of roots and natural abundance stable isotopic composition of N (δ15N) in plant leaves, roots, and soils. The root mycorrhizal community composition of understory trees did not significantly differ between beneath non-ECM and ECM overstory trees, although some OTUs more frequently appeared beneath non-ECM trees. Understory trees beneath non-ECM overstory trees had similar δ15N values in leaves and soil nitrate, suggesting that they took up most of their nitrogen as nitrate. Beneath ECM overstory trees, understory trees had consistently lower leaf than root δ15N, suggesting they depended on mycorrhizal fungi for N acquisition since mycorrhizal fungi transfer isotopically light N to host plants. Additionally, leaf N concentrations in the understory trees were lower beneath ECM than the non-ECM overstory trees. Our results show that, without large differences in root mycorrhizal community, the N uptake patterns of understory trees vary between beneath different overstory trees.
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Affiliation(s)
- Chikae Tatsumi
- Research Faculty of Agriculture, Hokkaido University, Sapporo, Japan
- Graduate School of Agriculture, Kyoto University, Kyoto, Japan
- Department of Biology, Boston University, Boston, MA, United States
| | - Fujio Hyodo
- Research Core for Interdisciplinary Sciences, Okayama University, Okayama, Japan
| | | | - Weiyu Shi
- School of Geographical Sciences, Southwest University, Chongqing, China
| | - Keisuke Koba
- Center for Ecological Research, Kyoto University, Shiga, Japan
| | | | - Sheng Du
- State Key Laboratory of Soil Erosion and Dryland Farming on Loess Plateau, Institute of Soil and Water Conservation, Chinese Academy of Sciences, Beijing, China
| | | | - Pamela Templer
- Department of Biology, Boston University, Boston, MA, United States
| | - Ryunosuke Tateno
- Field Science Education and Research Center, Kyoto University, Kyoto, Japan
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Chen L, Swenson NG, Ji N, Mi X, Ren H, Guo L, Ma K. Differential soil fungus accumulation and density dependence of trees in a subtropical forest. Science 2020; 366:124-128. [PMID: 31604314 DOI: 10.1126/science.aau1361] [Citation(s) in RCA: 95] [Impact Index Per Article: 23.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2018] [Revised: 06/27/2019] [Accepted: 08/22/2019] [Indexed: 01/02/2023]
Abstract
The mechanisms underlying interspecific variation in conspecific negative density dependence (CNDD) are poorly understood. Using a multilevel modeling approach, we combined long-term seedling demographic data from a subtropical forest plot with soil fungal community data by means of DNA sequencing to address the feedback of various guilds of soil fungi on the density dependence of trees. We show that mycorrhizal type mediates tree neighborhood interactions at the community level, and much of the interspecific variation in CNDD is explained by how tree species differ in their fungal density accumulation rates as they grow. Species with higher accumulation rates of pathogenic fungi suffered more from CNDD, whereas species with lower CNDD had higher accumulation rates of ectomycorrhizal fungi, suggesting that mutualistic and pathogenic fungi play important but opposing roles.
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Affiliation(s)
- Lei Chen
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
| | - Nathan G Swenson
- Department of Biology, University of Maryland, College Park, MD 20742, USA
| | - Niuniu Ji
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
| | - Xiangcheng Mi
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
| | - Haibao Ren
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
| | - Liangdong Guo
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
| | - Keping Ma
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China.
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7
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Gap creation alters the mode of conspecific distance-dependent seedling establishment via changes in the relative influence of pathogens and mycorrhizae. Oecologia 2020; 192:449-462. [PMID: 31960145 DOI: 10.1007/s00442-020-04596-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2019] [Accepted: 01/07/2020] [Indexed: 12/22/2022]
Abstract
In forest communities, conspecific density/distance dependence (CDD) is an important factor regulating diversity. It remains unknown how and the extent to which gap creation alters the mode and strength of CDD via changes in the relative importance of pathogens and mycorrhizae. Seeds of two hardwoods (i.e., Acer mono associated with arbuscular mycorrhizae [AM] and Quercus serrata associated with ectomycorrhizae [EM]) were sown reciprocally at four distances from the boundary between Acer- and Quercus-dominated forests towards forest interior in each of forest understories (FUs) and gaps. The causes of seed and seedling mortality, seedling growth and colonization of mycorrhizal fungi were investigated. In Acer, seed and seedling mortality were highest in Acer forests and gradually decreased towards the interior of Quercus forests in FU, mainly due to severe attack of soil pathogens, invertebrates, and leaf diseases. The reverse was true in gaps, due to reduction of damping-off damage caused by distance-dependent colonization of AM. In Quercus, most seeds and seedlings were eaten by vertebrates in FUs. The seedling mortality caused by leaf diseases was not high, even beneath conspecific forests with higher colonization of EM in gaps, suggesting a positive EM influence. In both species, seedling mass was greatest in conspecific forests and gradually decreased towards the interior of heterospecific forests in gaps, due to higher colonization of mycorrhizae near conspecifics. In conclusion, light conditions strongly altered the mode of CDD via changes in relative influence of pathogens and mycorrhizae, suggesting that gap creation may regulate species diversity via changes in the mode of CDD.
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8
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Forest Understorey Vegetation: Colonization and the Availability and Heterogeneity of Resources. FORESTS 2019. [DOI: 10.3390/f10110944] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Understorey vegetation comprises a major portion of plant diversity and contributes greatly to nutrient cycling and energy flow. This review examines the mechanisms involved in the response of understorey vegetation to stand development and the overstorey canopy following disturbances. The overall abundance and diversity of the understorey is enhanced with the availability and heterogeneity of light, soil nutrients, soil moisture, and substrates. Vascular plants are positively impacted by the availability and heterogeneity of light and soil nutrients, whereas non-vascular vegetation is more strongly influenced by colonization time, soil moisture, and substrates, and is decreased with a higher proportion of broadleaf overstorey. The availability of resources is a prominent driver toward the abundance and diversity of understorey vegetation, from the stand initiation to stem exclusion stage under a single-species dominated overstorey. However, resource heterogeneity dominates at the later stages of succession under a mixed overstorey. Climate and site conditions modify resource availability and heterogeneity in the understorey layer, but the extent of their influences requires more investigation. Forest management practices (clearcutting and partial harvesting) tend to increase light availability and heterogeneity, which facilitates the abundance and diversity of understorey vascular plants; however, these factors reduce the occurrence of non-vascular plants. Nevertheless, in the landscape context, anthropogenic disturbances homogenize environmental conditions and reduce beta-diversity, as well, the long-term effects of anthropogenic disturbances on understorey vegetation remain unclear, particularly compared with those in primary forests.
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Keller AB, Phillips RP. Leaf litter decay rates differ between mycorrhizal groups in temperate, but not tropical, forests. THE NEW PHYTOLOGIST 2019; 222:556-564. [PMID: 30299541 DOI: 10.1111/nph.15524] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/15/2018] [Accepted: 10/02/2018] [Indexed: 05/14/2023]
Abstract
Whereas the primary controls on litter decomposition are well established, we lack a framework for predicting interspecific differences in litter decay within and across ecosystems. Given previous research linking tree mycorrhizal association with carbon and nutrient dynamics, we hypothesized that the two dominant mycorrhizal groups in forests - arbuscular mycorrhizal (AM) and ectomycorrhizal (ECM) fungi - differ in litter decomposition rates. We compiled leaf litter chemistry and decay data for AM- and ECM-associating angiosperms and gymnosperms (> 200 species) from temperate and tropical/subtropical, and investigated relationships among decay rates, mycorrhizal association, phylogeny and climate. In temperate forests, AM litters decayed faster than ECM litters, with litter nitrogen and phylogeny best explaining variation in litter decay. In sub/tropical forests, we found no significant difference in litter decay rate between mycorrhizal groups, and variation in decay rates was best explained by litter phosphorus. Our results suggest that knowledge of tree mycorrhizal association may improve predictions of species effects on ecosystem processes, particularly in temperate forests where AM and ECM species commonly co-occur, providing a predictive framework for linking litter quality, organic matter dynamics and nutrient acquisition in forests.
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Affiliation(s)
- Adrienne B Keller
- Department of Biology, Indiana University, Jordan Hall, 1001 E. Third St, Bloomington, IN, 47405, USA
| | - Richard P Phillips
- Department of Biology, Indiana University, Jordan Hall, 1001 E. Third St, Bloomington, IN, 47405, USA
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Jo I, Fei S, Oswalt CM, Domke GM, Phillips RP. Shifts in dominant tree mycorrhizal associations in response to anthropogenic impacts. SCIENCE ADVANCES 2019; 5:eaav6358. [PMID: 30989116 PMCID: PMC6457943 DOI: 10.1126/sciadv.aav6358] [Citation(s) in RCA: 46] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/05/2018] [Accepted: 02/14/2019] [Indexed: 05/18/2023]
Abstract
Plant-fungal symbioses play critical roles in vegetation dynamics and nutrient cycling, modulating the impacts of global changes on ecosystem functioning. Here, we used forest inventory data consisting of more than 3 million trees to develop a spatially resolved "mycorrhizal tree map" of the contiguous United States. We show that abundances of the two dominant mycorrhizal tree groups-arbuscular mycorrhizal (AM) and ectomycorrhizal trees-are associated primarily with climate. Further, we show that anthropogenic influences, primarily nitrogen (N) deposition and fire suppression, in concert with climate change, have increased AM tree dominance during the past three decades in the eastern United States. Given that most AM-dominated forests in this region are underlain by soils with high N availability, our results suggest that the increasing abundance of AM trees has the potential to induce nutrient acceleration, with critical consequences for forest productivity, ecosystem carbon and nutrient retention, and feedbacks to climate change.
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Affiliation(s)
- Insu Jo
- Department of Forestry and Natural Resources, Purdue University, West Lafayette, IN 47907, USA
| | - Songlin Fei
- Department of Forestry and Natural Resources, Purdue University, West Lafayette, IN 47907, USA
| | - Christopher M. Oswalt
- Southern Research Station, Forest Service, U.S. Department of Agriculture, Knoxville, TN 37919, USA
| | - Grant M. Domke
- Northern Research Station, Forest Service, U.S. Department of Agriculture, St. Paul, MN 55108, USA
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11
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Impacts of climate on the biodiversity-productivity relationship in natural forests. Nat Commun 2018; 9:5436. [PMID: 30575752 PMCID: PMC6303326 DOI: 10.1038/s41467-018-07880-w] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2018] [Accepted: 11/30/2018] [Indexed: 12/15/2022] Open
Abstract
Understanding biodiversity-productivity relationships (BPRs) is of theoretical importance, and has important management implications. Most work on BPRs has focused on simple and/or experimentally assembled communities, and it is unclear how these observed BPRs can be extended to complex natural forest ecosystems. Using data from over 115,000 forest plots across the contiguous United States, we show that the bivariate BPRs are positive in dry climates and hump-shaped in mesic climates. When considering other site characteristics, BPRs change to neutral in dry climates and remain hump-shaped in humid sites. Our results indicate that climatic variation is an underlying determinant of contrasting BPRs observed across a large spatial extent, while both biotic factors (e.g., stand age and density) and abiotic factors (e.g., soil properties) can impact BPRs within a given climate unit. These findings suggest that tradeoffs need be made when considering whether to maximize productivity vs. conserve biodiversity, especially in mesic climates.
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12
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Contrasting dynamics and trait controls in first-order root compared with leaf litter decomposition. Proc Natl Acad Sci U S A 2018; 115:10392-10397. [PMID: 30254167 DOI: 10.1073/pnas.1716595115] [Citation(s) in RCA: 70] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Decomposition is a key component of the global carbon (C) cycle, yet current ecosystem C models do not adequately represent the contributions of plant roots and their mycorrhizae to this process. The understanding of decomposition dynamics and their control by traits is particularly limited for the most distal first-order roots. Here we followed decomposition of first-order roots and leaf litter from 35 woody plant species differing in mycorrhizal type over 6 years in a Chinese temperate forest. First-order roots decomposed more slowly (k = 0.11 ± 0.01 years-1) than did leaf litter (0.35 ± 0.02 years-1), losing only 35% of initial mass on average after 6 years of exposure in the field. In contrast to leaf litter, nonlignin root C chemistry (nonstructural carbohydrates, polyphenols) accounted for 82% of the large interspecific variation in first-order root decomposition. Leaf litter from ectomycorrhizal (EM) species decomposed more slowly than that from arbuscular mycorrhizal (AM) species, whereas first-order roots of EM species switched, after 2 years, from having slower to faster decomposition compared with those from AM species. The fundamentally different dynamics and control mechanisms of first-order root decomposition compared with those of leaf litter challenge current ecosystem C models, the recently suggested dichotomy between EM and AM plants, and the idea that common traits can predict decomposition across roots and leaves. Aspects of C chemistry unrelated to lignin or nitrogen, and not presently considered in decomposition models, controlled first-order root decomposition; thus, current paradigms of ecosystem C dynamics and model parameterization require revision.
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