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Chen X, Zhao H, Jiang G, Tang J, Xu Q, Li X, Huang Y, Zou S, Dong K, Hou W, Pan L, Wang P, Huang L, Li N. Trophic states regulate assembly processes and network structures of small chromophytic phytoplankton communities in estuarine and coastal ecosystem. MARINE POLLUTION BULLETIN 2022; 175:113327. [PMID: 35077925 DOI: 10.1016/j.marpolbul.2022.113327] [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: 09/06/2021] [Revised: 01/03/2022] [Accepted: 01/04/2022] [Indexed: 06/14/2023]
Abstract
Small chromophytic phytoplankton (SCP) are anticipated to be more important for a significant proportion of primary production in estuarine-coastal ecosystems. However, responses of SCP community to coastal eutrophication are still unclear. In this study, we investigated diversity, co-occurrence and assembly features of SCP communities, as well as relationship with environmental factors in subtropical Beibu Gulf. The results exhibited that the alpha diversity and beta diversity of SCP communities were significantly different among eutrophic states. Co-occurrence network revealed a complex interaction that most amplicon sequence variants (ASVs) in modules of the network were specific to trophic states. Further, phylogenetic based β-nearest taxon distance analyses revealed that stochastic processes mainly provided 69.26% contribution to SCP community assembly, whereas deterministic processes dominated community assembly in heavy eutrophic state. Overall, our findings elucidate the mechanism of diversity and assembly in SCP community and promote the understanding of SCP ecology related to subtropical coastal eutrophication.
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Affiliation(s)
- Xing Chen
- Key Laboratory of Environment Change and Resources Use in Beibu Gulf, Ministry of Education (Nanning Normal University), 175 Mingxiu East Road, Nanning 530001, China; College of Marine Life Sciences, Ocean University of China, Qingdao 266003, China
| | - Huaxian Zhao
- Key Laboratory of Environment Change and Resources Use in Beibu Gulf, Ministry of Education (Nanning Normal University), 175 Mingxiu East Road, Nanning 530001, China
| | - Gonglingxia Jiang
- Key Laboratory of Environment Change and Resources Use in Beibu Gulf, Ministry of Education (Nanning Normal University), 175 Mingxiu East Road, Nanning 530001, China
| | - Jinli Tang
- Key Laboratory of Environment Change and Resources Use in Beibu Gulf, Ministry of Education (Nanning Normal University), 175 Mingxiu East Road, Nanning 530001, China
| | - Qiangsheng Xu
- Key Laboratory of Environment Change and Resources Use in Beibu Gulf, Ministry of Education (Nanning Normal University), 175 Mingxiu East Road, Nanning 530001, China
| | - Xiaoli Li
- School of Agriculture, Ludong University, Yantai 264025, China
| | - Yuqing Huang
- Key Laboratory of Environment Change and Resources Use in Beibu Gulf, Ministry of Education (Nanning Normal University), 175 Mingxiu East Road, Nanning 530001, China
| | - Shuqi Zou
- Department of Biological Sciences, Kyonggi University, 154-42, Gwanggyosan-ro, Yeongtong-gu, Suwon-si, Gyeonggi-do 16227, South Korea
| | - Ke Dong
- Department of Biological Sciences, Kyonggi University, 154-42, Gwanggyosan-ro, Yeongtong-gu, Suwon-si, Gyeonggi-do 16227, South Korea
| | - Weiguo Hou
- State Key Laboratory of Biogeosciences and Environmental Geology and Institute of Earth Sciences, China University of Geosciences, Beijing 100083, China
| | - Lianghao Pan
- Guangxi Key Lab of Mangrove Conservation and Utilization, Guangxi Mangrove Research Center, Guangxi Academy of Sciences, 92 Changqing Road, Beihai, Guangxi 536000, China
| | - Pengbin Wang
- Fourth Institute of Oceanography, Ministry of Natural Resources, 26 New Century Avenue, Beihai 536000, China; Key Laboratory of Marine Ecosystem Dynamics, Second Institute of Oceanography, Ministry of Natural Resources, 36 Baochubei Road, Hangzhou 310012, China
| | - Liangliang Huang
- College of Environmental Science and Engineering, Guilin University of Technology, Guilin 541004, China
| | - Nan Li
- Key Laboratory of Environment Change and Resources Use in Beibu Gulf, Ministry of Education (Nanning Normal University), 175 Mingxiu East Road, Nanning 530001, China.
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2
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Kieft B, Li Z, Bryson S, Hettich RL, Pan C, Mayali X, Mueller RS. Phytoplankton exudates and lysates support distinct microbial consortia with specialized metabolic and ecophysiological traits. Proc Natl Acad Sci U S A 2021; 118:e2101178118. [PMID: 34620710 PMCID: PMC8521717 DOI: 10.1073/pnas.2101178118] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/09/2021] [Indexed: 11/18/2022] Open
Abstract
Blooms of marine phytoplankton fix complex pools of dissolved organic matter (DOM) that are thought to be partitioned among hundreds of heterotrophic microbes at the base of the food web. While the relationship between microbial consumers and phytoplankton DOM is a key component of marine carbon cycling, microbial loop metabolism is largely understood from model organisms and substrates. Here, we took an untargeted approach to measure and analyze partitioning of four distinct phytoplankton-derived DOM pools among heterotrophic populations in a natural microbial community using a combination of ecogenomics, stable isotope probing (SIP), and proteomics. Each 13C-labeled exudate or lysate from a diatom or a picocyanobacterium was preferentially assimilated by different heterotrophic taxa with specialized metabolic and physiological adaptations. Bacteroidetes populations, with their unique high-molecular-weight transporters, were superior competitors for DOM derived from diatom cell lysis, rapidly increasing growth rates and ribosomal protein expression to produce new relatively high C:N biomass. Proteobacteria responses varied, with relatively low levels of assimilation by Gammaproteobacteria populations, while copiotrophic Alphaproteobacteria such as the Roseobacter clade, with their diverse array of ABC- and TRAP-type transporters to scavenge monomers and nitrogen-rich metabolites, accounted for nearly all cyanobacteria exudate assimilation and produced new relatively low C:N biomass. Carbon assimilation rates calculated from SIP data show that exudate and lysate from two common marine phytoplankton are being used by taxonomically distinct sets of heterotrophic populations with unique metabolic adaptations, providing a deeper mechanistic understanding of consumer succession and carbon use during marine bloom events.
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Affiliation(s)
- Brandon Kieft
- Department of Microbiology, Oregon State University, Corvallis, OR 97331;
| | - Zhou Li
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37830
- Graduate School of Genome Science and Technology, The University of Tennessee, Knoxville, TN 37996
| | - Samuel Bryson
- Department of Microbiology, Oregon State University, Corvallis, OR 97331
- Department of Civil & Environmental Engineering, The University of Washington, Seattle, WA 98195
| | - Robert L Hettich
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37830
| | - Chongle Pan
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37830
- Graduate School of Genome Science and Technology, The University of Tennessee, Knoxville, TN 37996
- Department of Microbiology and Plant Microbiology, University of Oklahoma, Norman, OK 73019
| | - Xavier Mayali
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA 94550
| | - Ryan S Mueller
- Department of Microbiology, Oregon State University, Corvallis, OR 97331;
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3
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van der Lee GH, Vonk JA, Verdonschot RCM, Kraak MHS, Verdonschot PFM, Huisman J. Eutrophication induces shifts in the trophic position of invertebrates in aquatic food webs. Ecology 2020; 102:e03275. [PMID: 33351184 PMCID: PMC7988625 DOI: 10.1002/ecy.3275] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/11/2020] [Revised: 09/11/2020] [Accepted: 10/26/2020] [Indexed: 11/13/2022]
Abstract
Changes in the ecological stoichiometry of primary producers may have considerable implications for energy and matter transfer in food webs. We hypothesized that nutrient enrichment shifts the trophic position of omnivores towards herbivory, as the nutritional quality of primary producers increases. This hypothesis was tested by analyzing the ecological stoichiometry and stable isotope signature of primary producers and a wide range of aquatic macroinvertebrates, including primary consumers (herbivores) and secondary consumers (both potential omnivores and strict carnivores), along a eutrophication gradient in an agricultural landscape. Our results showed (1) that carbon : nutrient ratios of primary producers decreased along the eutrophication gradient, while the elemental composition of consumers remained homeostatic, and (2) that the trophic position of several omnivores and the generalist predator Notonecta decreased, while the trophic position of most other consumers remained constant. These findings suggest that shifts in the diets of aquatic invertebrates induced by increasing eutrophication may affect species interactions and food web structure in aquatic ecosystems.
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Affiliation(s)
- Gea H van der Lee
- Department of Freshwater and Marine Ecology, Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, P.O. Box 94240, Amsterdam, 1090 GE, The Netherlands.,Wageningen Environmental Research, Wageningen UR, P.O. Box 47, Wageningen, 6700 AA, The Netherlands
| | - J Arie Vonk
- Department of Freshwater and Marine Ecology, Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, P.O. Box 94240, Amsterdam, 1090 GE, The Netherlands
| | - Ralf C M Verdonschot
- Wageningen Environmental Research, Wageningen UR, P.O. Box 47, Wageningen, 6700 AA, The Netherlands
| | - Michiel H S Kraak
- Department of Freshwater and Marine Ecology, Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, P.O. Box 94240, Amsterdam, 1090 GE, The Netherlands
| | - Piet F M Verdonschot
- Department of Freshwater and Marine Ecology, Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, P.O. Box 94240, Amsterdam, 1090 GE, The Netherlands.,Wageningen Environmental Research, Wageningen UR, P.O. Box 47, Wageningen, 6700 AA, The Netherlands
| | - Jef Huisman
- Department of Freshwater and Marine Ecology, Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, P.O. Box 94240, Amsterdam, 1090 GE, The Netherlands
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Harris RJ, Arrington DA, Porter D, Lovko V. Documenting the duration and chlorophyll pigments of an allochthonous Karenia brevis bloom in the Loxahatchee River Estuary (LRE), Florida. HARMFUL ALGAE 2020; 97:101851. [PMID: 32732046 DOI: 10.1016/j.hal.2020.101851] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/24/2019] [Revised: 06/02/2020] [Accepted: 06/02/2020] [Indexed: 06/11/2023]
Abstract
In Fall 2017 a large bloom of the toxic dinoflagellate Karenia brevis developed in the Gulf of Mexico. After persisting for months, in Fall 2018 wind and water circulation patterns drove K. brevis towards the east coast of Florida. On September 29, 2018 Palm Beach County, FL beaches were closed due to respiratory and gastrointestinal issues associated with brevotoxins, and effects of brevotoxins were reported from within estuarine segments of the Loxahatchee River Estuary (LRE). This was the first apparent report of a K. brevis bloom impacting inshore portions of the LRE prompting us to question the longevity of K. brevis within a relatively shallow, well-flushed coastal-estuarine system. Within 3 days (October 1, 2018) of the first reported effects of toxins, K. brevis reached over one million cells/L and chlorophyll-a concentrations peaked at 13 µg L-1. Within 11 days (October 9, 2018) both K. brevis and chlorophyll pigment concentrations significantly (p-perm ≤ 0.05) dropped to an average of ≤ 30,000 cells L-1 and < 4 µg L-1 chlorophyll-a, indicating that the bloom had diminished. Using distance-based linear modeling (DistLM) K. brevis abundance alone explained 66% of the variation in a multivariate measure of chlorophylls (driven by carotenoids and chlorophyll-c pigment concentrations), supporting a K. brevis dominated bloom. Following the K. brevis bloom, additional HAB species K. mikimotoi and Pseudo-nitzschia spp singularly explained 6% of the variations in the multivariate measure of chlorophylls. The low explanatory power of individual HAB species, including K. brevis (≤ 0%), signifies the recovery of the phytoplankton population, where non-HAB species likely contributed to the variability in the multivariate measure of chlorophylls and overall chlorophyll-a concentrations (average of 2 µg L-1 during non-bloom conditions). Finally, we evaluated ambient and historical water quality data to assess how these parameters changed before, during, and after the 2018 K. brevis bloom. Temperature, salinity, and nutrients in the LRE were comparable to reports of other K. brevis bloom events along the west coast of Florida. Reduced ammonia-nitrogen (NH3-N) concentrations and increased tidal amplitude coincided with the end of the bloom in 2018. More work is needed to understand the specific mechanisms constraining K. brevis blooms in tidal estuaries. We suggest that future research focus on water residence times along with nutrient availability in controlling allochthonous HABs in lotic and tidally flushed estuaries. Also, we anticipate this work may stimulate additional efforts to characterize HABs using in situ observations coupled with multivariate measures of chlorophylls, though we recognize much work remains to fully define the value of this approach.
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Affiliation(s)
- Rachel J Harris
- Loxahatchee River District, 2500 Jupiter Park Drive, Jupiter, FL 33458, United States.
| | - D Albrey Arrington
- Loxahatchee River District, 2500 Jupiter Park Drive, Jupiter, FL 33458, United States
| | - David Porter
- Loxahatchee River District, 2500 Jupiter Park Drive, Jupiter, FL 33458, United States
| | - Vincent Lovko
- Mote Marine Laboratory, 1600 Ken Thompson Pkwy, Sarasota, FL 34236, United States
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Penuelas J, Janssens IA, Ciais P, Obersteiner M, Sardans J. Anthropogenic global shifts in biospheric N and P concentrations and ratios and their impacts on biodiversity, ecosystem productivity, food security, and human health. GLOBAL CHANGE BIOLOGY 2020; 26:1962-1985. [PMID: 31912629 DOI: 10.1111/gcb.14981] [Citation(s) in RCA: 68] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/09/2019] [Revised: 12/23/2019] [Accepted: 12/24/2019] [Indexed: 06/10/2023]
Abstract
The availability of carbon (C) from high levels of atmospheric carbon dioxide (CO2 ) and anthropogenic release of nitrogen (N) is increasing, but these increases are not paralleled by increases in levels of phosphorus (P). The current unstoppable changes in the stoichiometries of C and N relative to P have no historical precedent. We describe changes in P and N fluxes over the last five decades that have led to asymmetrical increases in P and N inputs to the biosphere. We identified widespread and rapid changes in N:P ratios in air, soil, water, and organisms and important consequences to the structure, function, and biodiversity of ecosystems. A mass-balance approach found that the combined limited availability of P and N was likely to reduce C storage by natural ecosystems during the remainder of the 21st Century, and projected crop yields of the Millennium Ecosystem Assessment indicated an increase in nutrient deficiency in developing regions if access to P fertilizer is limited. Imbalances of the N:P ratio would likely negatively affect human health, food security, and global economic and geopolitical stability, with feedbacks and synergistic effects on drivers of global environmental change, such as increasing levels of CO2 , climatic warming, and increasing pollution. We summarize potential solutions for avoiding the negative impacts of global imbalances of N:P ratios on the environment, biodiversity, climate change, food security, and human health.
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Affiliation(s)
- Josep Penuelas
- CSIC, Global Ecology Unit, CREAF-CSIC-UAB, Bellaterra, Spain
- CREAF, Cerdanyola del Valles, Spain
- Global Change Research Institute, Czech Academy of Sciences, Brno, Czech Republic
| | - Ivan A Janssens
- Research Group Plants and Ecosystems (PLECO), Department of Biology, University of Antwerp, Wilrijk, Belgium
| | - Philippe Ciais
- Laboratoire des Sciences du Climat et de l'Environnement, IPSL CEA CNRS UVSQ UPSACLAY, Gif-sur-Yvette, France
| | - Michael Obersteiner
- Ecosystems Services and Management, International Institute for Applied Systems Analysis (IIASA), Laxenburg, Austria
| | - Jordi Sardans
- CSIC, Global Ecology Unit, CREAF-CSIC-UAB, Bellaterra, Spain
- CREAF, Cerdanyola del Valles, Spain
- Global Change Research Institute, Czech Academy of Sciences, Brno, Czech Republic
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6
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Hofmann P, Chatzinotas A, Harpole WS, Dunker S. Temperature and stoichiometric dependence of phytoplankton traits. Ecology 2019; 100:e02875. [DOI: 10.1002/ecy.2875] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/04/2019] [Revised: 07/02/2019] [Accepted: 07/23/2019] [Indexed: 01/19/2023]
Affiliation(s)
- Peter Hofmann
- Department of Environmental Microbiology Helmholtz‐Centre for Environmental Research – UFZ Permoserstrasse 15 Leipzig 04318 Germany
- Department of Physiological Diversity Helmholtz‐Centre for Environmental Research – UFZ Permoserstrasse 15 Leipzig 04318 Germany
| | - Antonis Chatzinotas
- Department of Environmental Microbiology Helmholtz‐Centre for Environmental Research – UFZ Permoserstrasse 15 Leipzig 04318 Germany
- German Centre for Integrative Biodiversity Research (iDiv) Halle‐Jena‐Leipzig Deutscher Platz 5e Leipzig 04103 Germany
| | - W. Stanley Harpole
- Department of Physiological Diversity Helmholtz‐Centre for Environmental Research – UFZ Permoserstrasse 15 Leipzig 04318 Germany
- German Centre for Integrative Biodiversity Research (iDiv) Halle‐Jena‐Leipzig Deutscher Platz 5e Leipzig 04103 Germany
- Martin Luther University Halle‐Wittenberg Am Kirchtor 1 Halle (Saale) 06108 Germany
| | - Susanne Dunker
- Department of Physiological Diversity Helmholtz‐Centre for Environmental Research – UFZ Permoserstrasse 15 Leipzig 04318 Germany
- German Centre for Integrative Biodiversity Research (iDiv) Halle‐Jena‐Leipzig Deutscher Platz 5e Leipzig 04103 Germany
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7
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Novak T, Godrijan J, Pfannkuchen DM, Djakovac T, Medić N, Ivančić I, Mlakar M, Gašparović B. Global warming and oligotrophication lead to increased lipid production in marine phytoplankton. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 668:171-183. [PMID: 30852195 DOI: 10.1016/j.scitotenv.2019.02.372] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2018] [Revised: 02/19/2019] [Accepted: 02/24/2019] [Indexed: 06/09/2023]
Abstract
Earth temperature is rising and oligotrophication is becoming apparent even in coastal seas. In this changing environment, phytoplankton use carbon and nutrients to form important biomolecules, including lipids. However, the link between lipid production and changing environment is still unexplored. Therefore, we investigated the phytoplankton lipid production in the diatom Chaetoceros pseudocurvisetus cultures under controlled temperatures ranging from 10 to 30 °C and nutrient regimes mimicking oligotrophic and eutrophic conditions. Results were compared to plankton community's lipid production in the northern Adriatic at two stations considered as oligotrophic and mesotrophic during an annual monthly sampling. In order to gain detailed information on the investigated system, we supplemented lipid data with chlorophyll a concentrations, phytoplankton taxonomy, cell abundances and nutrient concentration along with hydrographic parameters. We found enhanced particulate lipid production at higher temperatures, and substantially higher lipid production in oligotrophic conditions. Enhanced lipid production has two opposing roles in carbon sequestration; it can act as a retainer or a sinker. Lipid remodeling, including change in ratio of phospholipids and glycolipids, is more affected by the nutrient status, than the temperature increase. Triacylglycerol accumulation was observed under the nitrogen starvation.
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Affiliation(s)
- Tihana Novak
- Division of Marine and Environmental Research, Ruđer Bošković Institute, POB 108, HR-10002 Zagreb, Croatia.
| | - Jelena Godrijan
- Division of Marine and Environmental Research, Ruđer Bošković Institute, POB 108, HR-10002 Zagreb, Croatia
| | | | - Tamara Djakovac
- Center for Marine Research, Ruđer Bošković Institute, G. Paliaga 5, HR-52210 Rovinj, Croatia
| | - Nikola Medić
- Marine Biological Section, Department of Biology, University of Copenhagen, DK-3000 Helsingør, Denmark
| | - Ingrid Ivančić
- Center for Marine Research, Ruđer Bošković Institute, G. Paliaga 5, HR-52210 Rovinj, Croatia
| | - Marina Mlakar
- Division of Marine and Environmental Research, Ruđer Bošković Institute, POB 108, HR-10002 Zagreb, Croatia
| | - Blaženka Gašparović
- Division of Marine and Environmental Research, Ruđer Bošković Institute, POB 108, HR-10002 Zagreb, Croatia
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8
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Wagner H, Jebsen C, Wilhelm C. Monitoring cellular C:N ratio in phytoplankton by means of FTIR-spectroscopy. JOURNAL OF PHYCOLOGY 2019; 55:543-551. [PMID: 30893470 DOI: 10.1111/jpy.12858] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/19/2018] [Accepted: 01/04/2019] [Indexed: 06/09/2023]
Abstract
Statistical growth rate modelling can be applied in a variety of ecological and biotechnological applications. Such models are frequently based on Monod or Droop equations and, especially for the latter, require reliable determination of model input parameters such as C:N quotas. Besides growth rate modelling, a C:N quota quantification can be useful for monitoring and interpretation of physiological acclimation to abiotic and biotic disturbances (e.g., nutrient limitations). However, as high throughput C:N quota determination is difficult to perform, alternatives need to be established. Fourier-transformed infrared (FTIR) spectroscopy is used to analyze a variety of biochemical, chemical, and physiological parameters in phytoplankton. Hence, a quantification of the C:N quota should also be feasible. Therefore, using FTIR spectroscopy, six phytoplankton species from among different phylogenetic groups have been analyzed to determine the effect of nutrient limitation on C:N quota patterns. The typical species-specific response to increasing nitrogen limitation was an increase in the C:N quota. Irrespective of this species specificity, we were able to develop a reliable multi-species C:N quota prediction model based on FTIR spectroscopy using the partial least square regression (PLSR) algorithm. Our data demonstrate that the PLSR approach is more robust in C:N quota quantification (R2 = 0.93) than linear correlation of C:N quota versus growth rate (R2 ranges from 0.74 to 0.86) or biochemical information based on FTIR spectra (R2 ranges from 0.82 to 0.89). This accurate prediction of C:N values may support high throughput measurements in a broad range of future approaches.
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Affiliation(s)
- Heiko Wagner
- Department of Plant Physiology, Institute of Biology, Leipzig University, Johannisallee 21-23, D-04103, Leipzig, Germany
| | - Christian Jebsen
- Department of Plant Physiology, Institute of Biology, Leipzig University, Johannisallee 21-23, D-04103, Leipzig, Germany
| | - Christian Wilhelm
- Department of Plant Physiology, Institute of Biology, Leipzig University, Johannisallee 21-23, D-04103, Leipzig, Germany
- German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Deutscher Platz 5e, D-04103, Leipzig, Germany
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9
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Burson A, Stomp M, Greenwell E, Grosse J, Huisman J. Competition for nutrients and light: testing advances in resource competition with a natural phytoplankton community. Ecology 2018; 99:1108-1118. [PMID: 29453803 DOI: 10.1002/ecy.2187] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/03/2017] [Revised: 01/26/2018] [Accepted: 01/29/2018] [Indexed: 11/08/2022]
Abstract
A key challenge in ecology is to understand how nutrients and light affect the biodiversity and community structure of phytoplankton and plant communities. According to resource competition models, ratios of limiting nutrients are major determinants of species composition. At high nutrient levels, however, species interactions may shift to competition for light, which might make nutrient ratios less relevant. The "nutrient-load hypothesis" merges these two perspectives, by extending the classic model of competition for two nutrients to include competition for light. Here, we test five key predictions of the nutrient-load hypothesis using multispecies competition experiments. A marine phytoplankton community sampled from the North Sea was inoculated in laboratory chemostats provided with different nitrogen (N) and phosphorus (P) loads to induce either single resource limitation or co-limitation of N, P, and light. Four of the five predictions were validated by the experiments. In particular, different resource limitations favored the dominance of different species. Increasing nutrient loads caused changes in phytoplankton species composition, even if the N:P ratio of the nutrient loads remained constant, by shifting the species interactions from competition for nutrients to competition for light. In all treatments, small species became dominant whereas larger species were competitively excluded, supporting the common view that small cell size provides a competitive advantage under resource-limited conditions. Contrary to expectation, all treatments led to coexistence of diatoms, cyanobacteria and green algae, resulting in a higher diversity of species than predicted by theory. Because the coexisting species comprised three phyla with different photosynthetic pigments, we speculate that niche differentiation in the light spectrum might play a role. Our results show that mechanistic resource competition models that integrate nutrient-based and light-based approaches provide an important step forward to understand and predict how changing nutrient loads affect community composition.
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Affiliation(s)
- Amanda Burson
- Department of Freshwater and Marine Ecology, Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, Amsterdam, The Netherlands
| | - Maayke Stomp
- Department of Freshwater and Marine Ecology, Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, Amsterdam, The Netherlands
| | - Emma Greenwell
- Department of Freshwater and Marine Ecology, Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, Amsterdam, The Netherlands
| | - Julia Grosse
- Department of Marine Microbiology and Biogeochemistry, Royal Netherlands Institute for Sea Research (NIOZ), Den Burg/Texel, The Netherlands
| | - Jef Huisman
- Department of Freshwater and Marine Ecology, Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, Amsterdam, The Netherlands
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