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Alvarenga DO, Clasen LA, Thomsen AMR, Andersen RF, Rousk K. Light drives nitrogen fixation in tropical montane cloud forests in Costa Rica. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 940:173631. [PMID: 38823705 DOI: 10.1016/j.scitotenv.2024.173631] [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: 04/06/2024] [Revised: 05/24/2024] [Accepted: 05/28/2024] [Indexed: 06/03/2024]
Abstract
Tropical montane cloud forests are high altitude ecosystems characterized by very high ambient humidity, which favors organisms that depend on the environment for their water status, such as bryophytes and their nitrogen-fixing symbionts. Bryophyte-associated N2 fixation is a major source of new N in several northern environments, but their contributions to the N cycle in other ecosystems is still poorly understood. In this work, we evaluated N2 fixation rates associated with epiphytic bryophytes growing along the stems of pumpwood trees (Cecropia sp.) as well as in surrounding litter and soil from a primary and a secondary cloud forests in the Talamanca Mountain Range, Costa Rica. Nitrogen fixation was significantly higher in substrates from the secondary forest compared to those from the primary forest. Overall, N2 fixation rates associated with epiphytic bryophytes were 57 times those of litter and 270 times what was measured in soil. Further, light intensity was the major factor influencing N2 fixation rates in all substrates. Increased access to light in disturbed cloud forests may therefore favor bryophyte-associated N2 fixation, potentially contributing to the recovery of these ecosystems.
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Affiliation(s)
- Danillo Oliveira Alvarenga
- Department of Biology, University of Copenhagen, Universitetsparken 15, DK-2100, Copenhagen, Denmark; Center for Volatile Interactions, University of Copenhagen, Universitetsparken 15, DK-2100 Copenhagen, Denmark.
| | - Lina Avila Clasen
- Department of Biology, University of Copenhagen, Universitetsparken 15, DK-2100, Copenhagen, Denmark; Center for Volatile Interactions, University of Copenhagen, Universitetsparken 15, DK-2100 Copenhagen, Denmark
| | - Amanda Maria Rydgren Thomsen
- Department of Biology, University of Copenhagen, Universitetsparken 15, DK-2100, Copenhagen, Denmark; Center for Volatile Interactions, University of Copenhagen, Universitetsparken 15, DK-2100 Copenhagen, Denmark
| | - Rune Fromm Andersen
- Department of Biology, University of Copenhagen, Universitetsparken 15, DK-2100, Copenhagen, Denmark; Center for Volatile Interactions, University of Copenhagen, Universitetsparken 15, DK-2100 Copenhagen, Denmark
| | - Kathrin Rousk
- Department of Biology, University of Copenhagen, Universitetsparken 15, DK-2100, Copenhagen, Denmark; Center for Volatile Interactions, University of Copenhagen, Universitetsparken 15, DK-2100 Copenhagen, Denmark
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Slate ML, Antoninka A, Bailey L, Berdugo MB, Callaghan DA, Cárdenas M, Chmielewski MW, Fenton NJ, Holland-Moritz H, Hopkins S, Jean M, Kraichak BE, Lindo Z, Merced A, Oke T, Stanton D, Stuart J, Tucker D, Coe KK. Impact of changing climate on bryophyte contributions to terrestrial water, carbon, and nitrogen cycles. THE NEW PHYTOLOGIST 2024; 242:2411-2429. [PMID: 38659154 DOI: 10.1111/nph.19772] [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: 12/20/2023] [Accepted: 03/22/2024] [Indexed: 04/26/2024]
Abstract
Bryophytes, including the lineages of mosses, liverworts, and hornworts, are the second-largest photoautotroph group on Earth. Recent work across terrestrial ecosystems has highlighted how bryophytes retain and control water, fix substantial amounts of carbon (C), and contribute to nitrogen (N) cycles in forests (boreal, temperate, and tropical), tundra, peatlands, grasslands, and deserts. Understanding how changing climate affects bryophyte contributions to global cycles in different ecosystems is of primary importance. However, because of their small physical size, bryophytes have been largely ignored in research on water, C, and N cycles at global scales. Here, we review the literature on how bryophytes influence global biogeochemical cycles, and we highlight that while some aspects of global change represent critical tipping points for survival, bryophytes may also buffer many ecosystems from change due to their capacity for water, C, and N uptake and storage. However, as the thresholds of resistance of bryophytes to temperature and precipitation regime changes are mostly unknown, it is challenging to predict how long this buffering capacity will remain functional. Furthermore, as ecosystems shift their global distribution in response to changing climate, the size of different bryophyte-influenced biomes will change, resulting in shifts in the magnitude of bryophyte impacts on global ecosystem functions.
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Affiliation(s)
- Mandy L Slate
- Department of Evolution, Ecology & Organismal Biology, The Ohio State University, Columbus, OH, 43210, USA
| | - Anita Antoninka
- School of Forestry, Northern Arizona University, Flagstaff, AZ, 86005, USA
| | - Lydia Bailey
- School of Forestry, Northern Arizona University, Flagstaff, AZ, 86005, USA
| | - Monica B Berdugo
- Plant Ecology and Geobotany, Department of Biology, University of Marburg, Karl-von-Frisch Str. 8, 35043, Marburg, Germany
| | - Des A Callaghan
- Bryophyte Surveys Ltd, Almondsbury, South Gloucestershire, BS32 4DU, UK
| | - Mariana Cárdenas
- Department of Ecology Evolution and Behavior, University of Minnesota, Saint Paul, MN, 55108, USA
| | | | - Nicole J Fenton
- Université du Québec en Abitibi-Témiscamingue, Rouyn-Noranda, QC, J9X 5E4, Canada
| | - Hannah Holland-Moritz
- Department of Natural Resources and the Environment, University of New Hampshire, Durham, NH, 03824, USA
| | - Samantha Hopkins
- Department of Biology, University of Western Ontario, London, ON, N6A 3K7, Canada
| | - Mélanie Jean
- Université de Moncton, Moncton, NB, E1A 3E9, Canada
| | - Bier Ekaphan Kraichak
- Department of Botany, Faculty of Science, Kasetsart University in Bangkok, Bangkok, 10900, Thailand
| | - Zoë Lindo
- Department of Biology, University of Western Ontario, London, ON, N6A 3K7, Canada
| | - Amelia Merced
- Department of Biology, University of Puerto Rico Río Piedras, San Juan, PR, 00925, USA
| | - Tobi Oke
- Wildlife Conservation Society & School of Environment & Sustainability, University of Saskatchewan, Saskatoon, SK, S7N 5C8, Canada
| | - Daniel Stanton
- Department of Ecology Evolution and Behavior, University of Minnesota, Saint Paul, MN, 55108, USA
| | - Julia Stuart
- College of Forest Resources and Environmental Science, Michigan Technological University, Houghton, MI, 49931, USA
- Mountain Planning Service Group, US Forest Service, Lakewood, CO, 80401, USA
| | - Daniel Tucker
- School of Environmental Studies, University of Victoria, Victoria, BC, V8P 5C2, Canada
| | - Kirsten K Coe
- Department of Biology, Middlebury College, Middlebury, VT, 05753, USA
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Nikolić N, Zotz G, Bader MY. Modelling the carbon balance in bryophytes and lichens: Presentation of PoiCarb 1.0, a new model for explaining distribution patterns and predicting climate-change effects. AMERICAN JOURNAL OF BOTANY 2024; 111:e16266. [PMID: 38038342 DOI: 10.1002/ajb2.16266] [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: 05/06/2023] [Revised: 10/27/2023] [Accepted: 10/30/2023] [Indexed: 12/02/2023]
Abstract
PREMISE Bryophytes and lichens have important functional roles in many ecosystems. Insight into their CO2 -exchange responses to climatic conditions is essential for understanding current and predicting future productivity and biomass patterns, but responses are hard to quantify at time scales beyond instantaneous measurements. We present PoiCarb 1.0, a model to study how CO2 -exchange rates of these poikilohydric organisms change through time as a function of weather conditions. METHODS PoiCarb simulates diel fluctuations of CO2 exchange and estimates long-term carbon balances, identifying optimal and limiting climatic patterns. Modelled processes were net photosynthesis, dark respiration, evaporation and water uptake. Measured CO2 -exchange responses to light, temperature, atmospheric CO2 concentration, and thallus water content (calculated in a separate module) were used to parameterize the model's carbon module. We validated the model by comparing modelled diel courses of net CO2 exchange to such courses from field measurements on the tropical lichen Crocodia aurata. To demonstrate the model's usefulness, we simulated potential climate-change effects. RESULTS Diel patterns were reproduced well, and the modelled and observed diel carbon balances were strongly positively correlated. Simulated warming effects via changes in metabolic rates were consistently negative, while effects via faster drying were variable, depending on the timing of hydration. CONCLUSIONS Reproducing weather-dependent variation in diel carbon balances is a clear improvement compared to simply extrapolating short-term measurements or potential photosynthetic rates. Apart from predicting climate-change effects, future uses of PoiCarb include testing hypotheses about distribution patterns of poikilohydric organisms and guiding conservation strategies for species.
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Affiliation(s)
- Nada Nikolić
- Faculty of Geography, Ecological Plant Geography, University of Marburg, Germany
| | - Gerhard Zotz
- University of Oldenburg, Institute for Biology and Environmental Sciences, Functional Ecology of Plants, Germany
| | - Maaike Y Bader
- Faculty of Geography, Ecological Plant Geography, University of Marburg, Germany
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Groß C, Hossen S, Dittrich S, Knorr KH, Borken W, Noll M. Biological nitrogen fixation, diversity and community structure of diazotrophs in two mosses in 25 temperate forests. Environ Microbiol 2024; 26:e16555. [PMID: 38148519 DOI: 10.1111/1462-2920.16555] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2023] [Accepted: 11/27/2023] [Indexed: 12/28/2023]
Abstract
Many moss species are associated with nitrogen (N)-fixing bacteria (diazotrophs) that support the N supply of mosses. Our knowledge relates primarily to pristine ecosystems with low atmospheric N input, but knowledge of biological N fixation (BNF) and diazotrophic communities in mosses in temperate forests with high N deposition is limited. We measured BNF rates using the direct stable isotope method and studied the total and potentially active diazotrophic communities in two abundant mosses, Brachythecium rutabulum and Hypnum cupressiforme, both growing on lying deadwood trunks in 25 temperate forest sites. BNF rates in both mosses were similar to those observed in moss species of pristine ecosystems. H. cupressiforme fixed three times more N2 and exhibited lower diazotrophic richness than B. rutabulum. Frankia was the most prominent diazotroph followed by cyanobacteria Nostoc. Manganese, iron, and molybdenum contents in mosses were positively correlated with BNF and diazotrophic communities. Frankia maintained high BNF rates in H. cupressiforme and B. rutabulum even under high chronic N deposition in Central European forests. Moss N concentration and 15 N abundance indicate a rather minor contribution of BNF to the N nutrition of these mosses.
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Affiliation(s)
- Christina Groß
- Department of Soil Ecology, University of Bayreuth, Bayreuth, Germany
| | - Shakhawat Hossen
- Institute for Bioanalysis, Coburg University of Applied Sciences and Arts, Coburg, Germany
| | - Sebastian Dittrich
- Biodiversity and Conservation, Technical University of Dresden, Tharandt, Germany
| | - Klaus-Holger Knorr
- Institute of Landscape Ecology, Ecohydrology and Biogeochemistry Group, University of Münster, Münster, Germany
| | - Werner Borken
- Department of Soil Ecology, University of Bayreuth, Bayreuth, Germany
| | - Matthias Noll
- Institute for Bioanalysis, Coburg University of Applied Sciences and Arts, Coburg, Germany
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García-Breijo FJ, Molins A, Reig-Armiñana J, Barreno E. The Tripartite Lichen Ricasolia virens: Involvement of Cyanobacteria and Bacteria in Its Morphogenesis. Microorganisms 2023; 11:1517. [PMID: 37375019 DOI: 10.3390/microorganisms11061517] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2023] [Revised: 05/31/2023] [Accepted: 06/05/2023] [Indexed: 06/29/2023] Open
Abstract
Ricasolia virens is an epiphytic lichen-forming fungus mainly distributed in Western Europe and Macaronesia in well-structured forests with ecological continuity that lack eutrophication. It is considered to be threatened or extinct in many territories in Europe (IUCN). Despite its biological and ecological relevance, studies on this taxon are scarce. The thalli are tripartite, and the mycobiont has a simultaneous symbiotic relationship with cyanobacteria and green microalgae, which represent interesting models to analyse the strategies and adaptations resulting from the interactions of lichen symbionts. The present study was designed to contribute to a better understanding of this taxon, which has shown a clear decline over the last century. The symbionts were identified by molecular analysis. The phycobiont is Symbiochloris reticulata, and the cyanobionts (Nostoc) are embedded in internal cephalodia. Light, transmission electron and low-temperature scanning microscopy techniques were used to investigate the thallus anatomy, ultrastructure of microalgae and ontogeny of pycnidia and cephalodia. The thalli are very similar to its closest relative, Ricasolia quercizans. The cellular ultrastructure of S. reticulata by TEM is provided. Non-photosynthetic bacteria located outside the upper cortex are introduced through migratory channels into the subcortical zone by the splitting of fungal hyphae. Cephalodia were very abundant, but never as external photosymbiodemes.
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Affiliation(s)
- Francisco J García-Breijo
- Departamento de Ecosistemas Agroforestales, ETSIAMN, Universitat Politècnica de València, Camino de Vera s/n, 46022 València, Spain
| | - Arantzazu Molins
- Instituto Cavanilles de Biodiversidad y Biología Evolutiva (ICBiBE), Botánica, Universitat de València, C/Dr. Moliner, 50, 46100 Burjassot, Spain
- Instituto de Investigaciones Agroambientales y de Economía del Agua (INAGEA), Departamento de Biología, Universitat de les Illes Balears (UIB), Ctra. Valldemossa Km.7., 07122 Palma de Malllorca, Spain
| | - José Reig-Armiñana
- Instituto Cavanilles de Biodiversidad y Biología Evolutiva (ICBiBE), Botánica, Universitat de València, C/Dr. Moliner, 50, 46100 Burjassot, Spain
| | - Eva Barreno
- Instituto Cavanilles de Biodiversidad y Biología Evolutiva (ICBiBE), Botánica, Universitat de València, C/Dr. Moliner, 50, 46100 Burjassot, Spain
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Avila Clasen L, Permin A, Horwath AB, Metcalfe DB, Rousk K. Do Nitrogen and Phosphorus Additions Affect Nitrogen Fixation Associated with Tropical Mosses? PLANTS (BASEL, SWITZERLAND) 2023; 12:1443. [PMID: 37050067 PMCID: PMC10097241 DOI: 10.3390/plants12071443] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/09/2022] [Revised: 03/15/2023] [Accepted: 03/17/2023] [Indexed: 06/19/2023]
Abstract
Tropical cloud forests are characterized by abundant and biodiverse mosses which grow epiphytically as well as on the ground. Nitrogen (N)-fixing cyanobacteria live in association with most mosses, and contribute greatly to the N pool via biological nitrogen fixation (BNF). However, the availability of nutrients, especially N and phosphorus (P), can influence BNF rates drastically. To evaluate the effects of increased N and P availability on BNF in mosses, we conducted a laboratory experiment where we added N and P, in isolation and combined, to three mosses (Campylopus sp., Dicranum sp. and Thuidium peruvianum) collected from a cloud forest in Peru. Our results show that N addition almost completely inhibited BNF within a day, whereas P addition caused variable results across moss species. Low N2 fixation rates were observed in Campylopus sp. across the experiment. BNF in Dicranum sp. was decreased by all nutrients, while P additions seemed to promote BNF in T. peruvianum. Hence, each of the three mosses contributes distinctively to the ecosystem N pool depending on nutrient availability. Moreover, increased N input will likely significantly decrease BNF associated with mosses also in tropical cloud forests, thereby limiting N input to these ecosystems via the moss-cyanobacteria pathway.
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Affiliation(s)
- Lina Avila Clasen
- Department of Biology, University of Copenhagen, Universitetsparken 15, 2100 Copenhagen, Denmark (K.R.)
| | - Aya Permin
- Department of Biology, University of Copenhagen, Universitetsparken 15, 2100 Copenhagen, Denmark (K.R.)
| | - Aline B. Horwath
- Biological and Environmental Sciences, Faculty of Natural Sciences, University of Stirling, Stirling FK9 4LA, UK
| | - Daniel B. Metcalfe
- Department of Physical Geography and Ecosystem Science, Lund University, 221 00 Lund, Sweden
- Department of Ecology and Environmental Science, University of Umeå, 907 36 Umeå, Sweden
| | - Kathrin Rousk
- Department of Biology, University of Copenhagen, Universitetsparken 15, 2100 Copenhagen, Denmark (K.R.)
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Chen KH, Nelson J. A scoping review of bryophyte microbiota: diverse microbial communities in small plant packages. JOURNAL OF EXPERIMENTAL BOTANY 2022; 73:4496-4513. [PMID: 35536989 DOI: 10.1093/jxb/erac191] [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: 12/31/2021] [Accepted: 05/05/2022] [Indexed: 06/14/2023]
Abstract
Plant health depends not only on the condition of the plant itself but also on its diverse community of microbes, or microbiota. Just like the better-studied angiosperms, bryophytes (mosses, liverworts, and hornworts) harbor diverse communities of bacteria, archaea, fungi, and other microbial eukaryotes. Bryophytes are increasingly recognized as important model systems for understanding plant evolution, development, physiology, and symbiotic interactions. Much of the work on bryophyte microbiota in the past focused on specific symbiont types for each bryophyte group, but more recent studies are taking a broader view acknowledging the coexistence of diverse microbial communities in bryophytes. Therefore, this review integrates studies of bryophyte microbes from both perspectives to provide a holistic view of the existing research for each bryophyte group and on key themes. The systematic search also reveals the taxonomic and geographic biases in this field, including a severe under-representation of the tropics, very few studies on viruses or eukaryotic microbes beyond fungi, and a focus on mycorrhizal fungi studies in liverworts. Such gaps may have led to errors in conclusions about evolutionary patterns in symbiosis. This analysis points to a wealth of future research directions that promise to reveal how the distinct life cycles and physiology of bryophytes interact with their microbiota.
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Affiliation(s)
- Ko-Hsuan Chen
- Biodiversity Research Center, Academia Sinica, Taipei, Taiwan
| | - Jessica Nelson
- Maastricht Science Programme, Maastricht University, Maastricht, The Netherlands
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Alvarenga DO, Rousk K. Unraveling host-microbe interactions and ecosystem functions in moss-bacteria symbioses. JOURNAL OF EXPERIMENTAL BOTANY 2022; 73:4473-4486. [PMID: 35728619 DOI: 10.1093/jxb/erac091] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/04/2021] [Accepted: 06/15/2022] [Indexed: 06/15/2023]
Abstract
Mosses are non-vascular plants usually found in moist and shaded areas, with great ecological importance in several ecosystems. This is especially true in northern latitudes, where mosses are responsible for up to 100% of primary production in some ecosystems. Mosses establish symbiotic associations with unique bacteria that play key roles in the carbon and nitrogen cycles. For instance, in boreal environments, more than 35% of the nitrogen fixed by diazotrophic symbionts in peatlands is transferred to mosses, directly affecting carbon fixation by the hosts, while moss-associated methanotrophic bacteria contribute 10-30% of moss carbon. Further, half of ecosystem N input may derive from moss-cyanobacteria associations in pristine ecosystems. Moss-bacteria interactions have consequences on a global scale since northern environments sequester 20% of all the carbon generated by forests in the world and stock at least 32% of global terrestrial carbon. Different moss hosts influence bacteria in distinct ways, which suggests that threats to mosses also threaten unique microbial communities with important ecological and biogeochemical consequences. Since their origin ~500 Ma, mosses have interacted with bacteria, making these associations ideal models for understanding the evolution of plant-microbe associations and their contribution to biogeochemical cycles.
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Affiliation(s)
- Danillo O Alvarenga
- Department of Biology, Terrestrial Ecology Section, University of Copenhagen, Universitetsparken 15, DK-2100, Copenhagen, Denmark
- Centre for Permafrost, University of Copenhagen, Øster Voldgade 10, DK-1350, Copenhagen, Denmark
| | - Kathrin Rousk
- Department of Biology, Terrestrial Ecology Section, University of Copenhagen, Universitetsparken 15, DK-2100, Copenhagen, Denmark
- Centre for Permafrost, University of Copenhagen, Øster Voldgade 10, DK-1350, Copenhagen, Denmark
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