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Wickman J, Litchman E, Klausmeier CA. Eco-evolutionary emergence of macroecological scaling in plankton communities. Science 2024; 383:777-782. [PMID: 38359116 DOI: 10.1126/science.adk6901] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2023] [Accepted: 01/17/2024] [Indexed: 02/17/2024]
Abstract
Macroecological scaling patterns, such as between prey and predator biomass, are fundamental to our understanding of the rules of biological organization and ecosystem functioning. Although these scaling patterns are ubiquitous, how they arise is poorly understood. To explain these patterns, we used an eco-evolutionary predator-prey model parameterized using data for phytoplankton and zooplankton. We show that allometric scaling relationships at lower levels of biological organization, such as body-size scaling of nutrient uptake and predation, give rise to scaling relationships at the food web and ecosystem levels. Our predicted macroecological scaling exponents agree well with observed values across ecosystems. Our findings explicitly connect scaling relationships at different levels of biological organization to ecological and evolutionary mechanisms, yielding testable hypotheses for how observed macroecological patterns emerge.
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Affiliation(s)
- Jonas Wickman
- W. K. Kellogg Biological Station, Michigan State University, Hickory Corners, MI, USA
- Program in Ecology, Evolution, and Behavior, Michigan State University, East Lansing, MI, USA
| | - Elena Litchman
- W. K. Kellogg Biological Station, Michigan State University, Hickory Corners, MI, USA
- Program in Ecology, Evolution, and Behavior, Michigan State University, East Lansing, MI, USA
- Department of Global Ecology, Carnegie Institution for Science, Stanford, CA, USA
- Department of Integrative Biology, Michigan State University, East Lansing, MI, USA
| | - Christopher A Klausmeier
- W. K. Kellogg Biological Station, Michigan State University, Hickory Corners, MI, USA
- Program in Ecology, Evolution, and Behavior, Michigan State University, East Lansing, MI, USA
- Department of Global Ecology, Carnegie Institution for Science, Stanford, CA, USA
- Department of Integrative Biology, Michigan State University, East Lansing, MI, USA
- Department of Plant Biology, Michigan State University, East Lansing, MI, USA
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2
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Liu L, Fan M, Kang Y. Effect of nutrient supply on cell size evolution of marine phytoplankton. MATHEMATICAL BIOSCIENCES AND ENGINEERING : MBE 2023; 20:4714-4740. [PMID: 36896519 DOI: 10.3934/mbe.2023218] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
The variation of nutrient supply not only leads to the differences in the phytoplankton biomass and primary productivity but also induces the long-term phenotypic evolution of phytoplankton. It is widely accepted that marine phytoplankton follows Bergmann's Rule and becomes smaller with climate warming. Compared with the direct effect of increasing temperature, the indirect effect via nutrient supply is considered to be an important and dominant factor in the reduction of phytoplankton cell size. In this paper, a size-dependent nutrient-phytoplankton model is developed to explore the effects of nutrient supply on the evolutionary dynamics of functional traits associated with phytoplankton size. The ecological reproductive index is introduced to investigate the impacts of input nitrogen concentration and vertical mixing rate on the persistence of phytoplankton and the distribution of cell size. In addition, by applying the adaptive dynamics theory, we study the relationship between nutrient input and the evolutionary dynamics of phytoplankton. The results show that input nitrogen concentration and vertical mixing rate have significant effects on the cell size evolution of phytoplankton. Specifically, cell size tends to increase with the input nutrient concentration, as does the diversity of cell sizes. In addition, a single-peaked relationship between vertical mixing rate and cell size is observed. When the vertical mixing rate is too low or too high, only small individuals are dominant in the water column. When the vertical mixing rate is moderate, large individuals can coexist with small individuals, so the diversity of phytoplankton is elevated. We predict that reduced intensity of nutrient input due to climate warming will lead to a trend towards smaller cell size and will reduce the diversity of phytoplankton.
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Affiliation(s)
- Lidan Liu
- School of Mathematics and Statistics, Northeast Normal University, Changchun, Jilin 130024, China
| | - Meng Fan
- School of Mathematics and Statistics, Northeast Normal University, Changchun, Jilin 130024, China
| | - Yun Kang
- College of Integrative Sciences and Arts, Arizona State University, Mesa, AZ 85212, USA
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3
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Mai G, Song X, Xia X, Ma Z, Tan Y, Li G. Photosynthetic Characteristics of Smaller and Larger Cell Size-Fractioned Phytoplankton Assemblies in the Daya Bay, Northern South China Sea. Microorganisms 2021; 10:microorganisms10010016. [PMID: 35056465 PMCID: PMC8846320 DOI: 10.3390/microorganisms10010016] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2021] [Revised: 12/20/2021] [Accepted: 12/20/2021] [Indexed: 11/16/2022] Open
Abstract
Cell size of phytoplankton is known to influence their physiologies and, consequently, marine primary production. To characterize the cell size-dependent photophysiology of phytoplankton, we comparably explored the photosynthetic characteristics of piconano- (<20 µm) and micro-phytoplankton cell assemblies (>20 µm) in the Daya Bay, northern South China Sea, using a 36-h in situ high-temporal-resolution experiment. During the experimental periods, the phytoplankton biomass (Chl a) in the surface water ranged from 0.92 to 5.13 μg L-1, which was lower than that in bottom layer (i.e., 1.83-6.84 μg L-1). Piconano-Chl a accounted for 72% (mean value) of the total Chl a, with no significant difference between the surface and bottom layers. The maximum photochemical quantum yield (FV/FM) of Photosystem II (PS II) and functional absorption cross-section of PS II photochemistry (σPS II) of both piconano- and micro-cells assemblies varied inversely with solar radiation, but this occurred to a lesser extent in the former than in the latter ones. The σPS II of piconano- and micro-cell assemblies showed a similar change pattern to the FV/FM in daytime, but not in nighttime. Moreover, the fluorescence light curve (FLC)-derived light utilization efficiency (α) displayed the same daily change pattern as the FV/FM, and the saturation irradiance (EK) and maximal rETR (rETRmax) mirrored the change in the solar radiation. The FV/FM and σPS II of the piconano-cells were higher than their micro-counterparts under high solar light; while the EK and rETRmax were lower, no matter in what light regimes. In addition, our results indicate that the FV/FM of the micro-cell assembly varied quicker in regard to Chl a change than that of the piconano-cell assembly, indicating the larger phytoplankton cells are more suitable to grow than the smaller ones in the Daya Bay through timely modulating the PS II activity.
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Affiliation(s)
- Guangming Mai
- Key Laboratory of Tropical Marine Bio-Resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510530, China; (G.M.); (X.S.); (X.X.); (Y.T.)
- Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou 511458, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xingyu Song
- Key Laboratory of Tropical Marine Bio-Resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510530, China; (G.M.); (X.S.); (X.X.); (Y.T.)
- Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou 511458, China
- University of Chinese Academy of Sciences, Beijing 100049, China
- Nansha Marine Ecological and Environmental Research Station, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510530, China
| | - Xiaomin Xia
- Key Laboratory of Tropical Marine Bio-Resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510530, China; (G.M.); (X.S.); (X.X.); (Y.T.)
- Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou 511458, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Zengling Ma
- National and Local Joint Engineering Research Center of Ecological Treatment Technology for Urban Water Pollution, Wenzhou University, Wenzhou 325035, China;
| | - Yehui Tan
- Key Laboratory of Tropical Marine Bio-Resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510530, China; (G.M.); (X.S.); (X.X.); (Y.T.)
- Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou 511458, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Gang Li
- Key Laboratory of Tropical Marine Bio-Resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510530, China; (G.M.); (X.S.); (X.X.); (Y.T.)
- Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou 511458, China
- University of Chinese Academy of Sciences, Beijing 100049, China
- Correspondence:
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4
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Hillebrand H, Acevedo‐Trejos E, Moorthi SD, Ryabov A, Striebel M, Thomas PK, Schneider M. Cell size as driver and sentinel of phytoplankton community structure and functioning. Funct Ecol 2021. [DOI: 10.1111/1365-2435.13986] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Helmut Hillebrand
- Institute for Chemistry and Biology of Marine Environments [ICBM] Plankton Ecology Lab Carl‐von‐Ossietzky University Oldenburg Wilhelmshaven Germany
- Helmholtz‐Institute for Functional Marine Biodiversity at the University of Oldenburg [HIFMB] Oldenburg Germany
- Alfred Wegener Institute Helmholtz‐Centre for Polar and Marine Research [AWI] Bremerhaven Germany
| | - Esteban Acevedo‐Trejos
- Earth Surface Process Modelling Helmholtz Centre Potsdam GFZ German Research Centre for Geosciences Potsdam Germany
| | - Stefanie D. Moorthi
- Institute for Chemistry and Biology of Marine Environments [ICBM] Plankton Ecology Lab Carl‐von‐Ossietzky University Oldenburg Wilhelmshaven Germany
| | - Alexey Ryabov
- Institute for Chemistry and Biology of Marine Environments [ICBM] Mathematical Modelling Carl‐von‐Ossietzky University Oldenburg Oldenburg Germany
- Institute of Forest Growth and Computer Science Technische Universität Dresden Tharandt Germany
| | - Maren Striebel
- Institute for Chemistry and Biology of Marine Environments [ICBM] Plankton Ecology Lab Carl‐von‐Ossietzky University Oldenburg Wilhelmshaven Germany
| | - Patrick K. Thomas
- Institute for Chemistry and Biology of Marine Environments [ICBM] Plankton Ecology Lab Carl‐von‐Ossietzky University Oldenburg Wilhelmshaven Germany
| | - Marie‐Luise Schneider
- Institute for Chemistry and Biology of Marine Environments [ICBM] Plankton Ecology Lab Carl‐von‐Ossietzky University Oldenburg Wilhelmshaven Germany
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5
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Liu H, Dai C, Yu H, Guo Q, Li J, Hao A, Kikuchi J, Zhao M. Dynamics induced by environmental stochasticity in a phytoplankton-zooplankton system with toxic phytoplankton. MATHEMATICAL BIOSCIENCES AND ENGINEERING : MBE 2021; 18:4101-4126. [PMID: 34198428 DOI: 10.3934/mbe.2021206] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Environmental stochasticity and toxin-producing phytoplankton (TPP) are the key factors that affect the aquatic ecosystems. To investigate the effects of environmental stochasticity and TPP on the dynamics of plankton populations, a stochastic phytoplankton-zooplankton system with two TPP is studied theoretically and numerically in this paper. Theoretically, we first prove that the system possesses a unique and global positive solution with positive initial values, and then derive some sufficient conditions guaranteeing the extinction and persistence in the mean of the system. Significantly, it is shown that the system has a stationary distribution when toxin liberation rate reaches some a critical value. Additionally, numerical analysis shows that the white noise can affect the survival of plankton populations directly. Furthermore, it has been observed that the increasing one toxin liberation rate can increase the survival chance of phytoplankton and reduce the biomass of zooplankton, but the combined effects of two liberation rates on the changes in plankton populations are stronger than that of controlling any one of the two TPP.
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Affiliation(s)
- He Liu
- School of Life and Environmental Science, Wenzhou University, Wenzhou 325035, China
- Environmental Engineering Program, University of Northern British Columbia, 3333 University Way, Prince George, BC, V2N 4Z9, Canada
| | - Chuanjun Dai
- School of Life and Environmental Science, Wenzhou University, Wenzhou 325035, China
- National & Local Joint Engineering Research Center for Ecological Treatment Technology of Urban Water Pollution, Wenzhou University, Wenzhou 325035, China
| | - Hengguo Yu
- National & Local Joint Engineering Research Center for Ecological Treatment Technology of Urban Water Pollution, Wenzhou University, Wenzhou 325035, China
| | - Qing Guo
- School of Life and Environmental Science, Wenzhou University, Wenzhou 325035, China
- Environmental Engineering Program, University of Northern British Columbia, 3333 University Way, Prince George, BC, V2N 4Z9, Canada
| | - Jianbing Li
- Environmental Engineering Program, University of Northern British Columbia, 3333 University Way, Prince George, BC, V2N 4Z9, Canada
- WZU-UNBC Joint Research Institute of Ecology and Environment, Wenzhou University, Wenzhou 325035, China
| | - Aimin Hao
- School of Life and Environmental Science, Wenzhou University, Wenzhou 325035, China
| | - Jun Kikuchi
- RIKEN Center for Sustainable Resource Science, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa 230-0045, Japan
| | - Min Zhao
- School of Life and Environmental Science, Wenzhou University, Wenzhou 325035, China
- Environmental Engineering Program, University of Northern British Columbia, 3333 University Way, Prince George, BC, V2N 4Z9, Canada
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6
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Orkney A, Platt T, Narayanaswamy BE, Kostakis I, Bouman HA. Bio-optical evidence for increasing Phaeocystis dominance in the Barents Sea. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2020; 378:20190357. [PMID: 32862820 PMCID: PMC7481673 DOI: 10.1098/rsta.2019.0357] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Increasing contributions of prymnesiophytes such as Phaeocystis pouchetii and Emiliania huxleyi to Barents Sea (BS) phytoplankton production have been suggested based on in situ observations of phytoplankton community composition, but the scattered and discontinuous nature of these records confounds simple inference of community change or its relationship to salient environmental variables. However, provided that meaningful assessments of phytoplankton community composition can be inferred based on their optical characteristics, ocean-colour records offer a potential means to develop a synthesis between sporadic in situ observations. Existing remote-sensing algorithms to retrieve phytoplankton functional types based on chlorophyll-a (chl-a) concentration or indices of pigment packaging may, however, fail to distinguish Phaeocystis from other blooms of phytoplankton with high pigment packaging, such as diatoms. We develop a novel algorithm to distinguish major phytoplankton functional types in the BS and apply it to the MODIS-Aqua ocean-colour record, to study changes in the composition of BS phytoplankton blooms in July, between 2002 and 2018, creating time series of the spatial distribution and intensity of coccolithophore, diatom and Phaeocystis blooms. We confirm a north-eastward expansion in coccolithophore bloom distribution, identified in previous studies, and suggest an inferred increase in chl-a concentrations, reported by previous researchers, may be partly explained by increasing frequencies of Phaeocystis blooms. This article is part of the theme issue 'The changing Arctic Ocean: consequences for biological communities, biogeochemical processes and ecosystem functioning'.
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Affiliation(s)
- A. Orkney
- Department of Earth Sciences, University of Oxford, 3 South Parks Road, Oxford OX1 3AN, UK
- e-mail:
| | - T. Platt
- Plymouth Marine Laboratory, Prospect Place, Plymouth PL1 3DH, UK
| | - B. E. Narayanaswamy
- Scottish Association for Marine Science, Scottish Marine Institute, Oban PA37 1QA, UK
| | - I. Kostakis
- School of Computing, University of Portsmouth, Portsmouth PO1 3HE, UK
- Physics Department, University of Strathclyde, Glasgow G4 ONG, UK
| | - H. A. Bouman
- Department of Earth Sciences, University of Oxford, 3 South Parks Road, Oxford OX1 3AN, UK
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7
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Wang C, Baseler S, Lin S. Glycerol Utilization By Phytoplankton 1. JOURNAL OF PHYCOLOGY 2020; 56:1157-1167. [PMID: 32452560 DOI: 10.1111/jpy.13031] [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: 11/06/2019] [Accepted: 05/06/2020] [Indexed: 06/11/2023]
Abstract
Dissolved organic carbon (DOC) is an important source of carbon and energy for microbes, but whether it can be used by phytoplankton has not been systematically studied, and the underlying molecular metabolism remains poorly understood. Here, we investigated the ability of phytoplankton to utilize glycerol as a representative of DOC. The widespread presence and expression of glycerol transporter genes were found in transcriptomes and genomes, suggesting the glycerol utilization potential in the diverse marine phytoplankton. We surveyed 29 representative phytoplankton species (31 strains) from six phyla for their ability to use glycerol. Three types of responses were found: positive utilization (Type I), no response (Type II), and negative response (Type III). In all, 11 Type I species were further investigated in axenic cultures with different glycerol concentrations, and five species showed intrinsic glycerol utilizing ability without the aid of bacteria. The ability of species to use glycerol to support non-photosynthetic (DCMU treated) growth was consistent with their possession and expression of glycerol transporter genes. However, some species from the Type II and Type III also possess and express the genes, raising a question whether glycerol transporter in algae might have diversified its function to glycerol export or even non-glycerol transport. Our results show that glycerol could serve as organic carbon source, harmless xenobiotics, or growth inhibitors for phytoplankton depending on species, indicating that glycerol, including natural sources or human discharges, may shape the marine phytoplankton community structure, especially under low photosynthetic efficiency conditions.
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Affiliation(s)
- Cong Wang
- State Key Laboratory of Marine Environmental Science and College of the Environment and Ecology, Xiamen University, Xiamen, Fujian, China
| | - Sarah Baseler
- Department of Marine Sciences, University of Connecticut, Groton, CT, USA
| | - Senjie Lin
- Department of Marine Sciences, University of Connecticut, Groton, CT, USA
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8
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Flynn KJ, Skibinski DOF. Exploring evolution of maximum growth rates in plankton. JOURNAL OF PLANKTON RESEARCH 2020; 42:497-513. [PMID: 32939154 PMCID: PMC7484936 DOI: 10.1093/plankt/fbaa038] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/17/2020] [Accepted: 08/03/2020] [Indexed: 05/15/2023]
Abstract
Evolution has direct and indirect consequences on species-species interactions and the environment. However, Earth systems models describing planktonic activity invariably fail to explicitly consider organism evolution. Here we simulate the evolution of the single most important physiological characteristic of any organism as described in models-its maximum growth rate (μm). Using a low-computational-cost approach, we incorporate the evolution of μm for each of the plankton components in a simple Nutrient-Phytoplankton-Zooplankton -style model such that the fitness advantages and disadvantages in possessing a high μm evolve to become balanced. The model allows an exploration of parameter ranges leading to stresses, which drive the evolution of μm. In applications of the method we show that simulations of climate change give very different projections when the evolution of μm is considered. Thus, production may decline as evolution reshapes growth and trophic dynamics. Additionally, predictions of extinction of species may be overstated in simulations lacking evolution as the ability to evolve under changing environmental conditions supports evolutionary rescue. The model explains why organisms evolved for mature ecosystems (e.g. temperate summer, reliant on local nutrient recycling or mixotrophy), express lower maximum growth rates than do organisms evolved for immature ecosystems (e.g. temperate spring, high resource availability).
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9
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Durante G, Basset A, Stanca E, Roselli L. Allometric scaling and morphological variation in sinking rate of phytoplankton. JOURNAL OF PHYCOLOGY 2019; 55:1386-1393. [PMID: 31483867 DOI: 10.1111/jpy.12916] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2019] [Accepted: 08/17/2019] [Indexed: 06/10/2023]
Abstract
Since the first decades of the last century, several hypotheses have been proposed on the role of phytoplankton morphology in maintaining a favorable position in the water column. Here, by an extensive review of literature on sinking rate and cell volume, we firstly attempted to explore the dependency of sinking rate on morphological traits using the allometric scaling approach. We found that sinking rate tends to increase with increasing cell volume showing the allometric scaling exponent of 0.43, which is significantly different than the Stokes' law exponent of 0.66. The violation of the 2/3 power rule clearly indicates that cell shape changes as size increases. Both size and shape affect how phytoplankton sinking drives nutrient acquisition and losses to sinking. Interestingly, from an evolutionary perspective, simple and complex cylindrical shapes can get much larger than spherical and spheroidal shapes and sink at similar rates, but simple and complex cylindrical shapes cannot get small enough to sink slower than small spherical and spheroidal shapes. Cell shape complexity is a morphological attribute resulting from the combination of two or more simple geometric shapes. While the effect of size on sinking rate is well documented, this study deepens the knowledge on how cell shape or geometry affect sinking rates that still needs further consideration.
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Affiliation(s)
- Giulia Durante
- Department of Biological and Environmental Science and Technologies, University of Salento, I-73100, Lecce, Italy
| | - Alberto Basset
- Department of Biological and Environmental Science and Technologies, University of Salento, I-73100, Lecce, Italy
| | - Elena Stanca
- Department of Biological and Environmental Science and Technologies, University of Salento, I-73100, Lecce, Italy
| | - Leonilde Roselli
- Department of Biological and Environmental Science and Technologies, University of Salento, I-73100, Lecce, Italy
- Department of Lecce, Regional Agency for the Environmental Prevention and Protection (ARPA Puglia), 73100, Lecce, Italy
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10
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Branco P, Egas M, Hall SR, Huisman J. Why Do Phytoplankton Evolve Large Size in Response to Grazing? Am Nat 2019; 195:E20-E37. [PMID: 31868537 DOI: 10.1086/706251] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Phytoplankton are among the smallest primary producers on Earth, yet they display a wide range of cell sizes. Typically, small phytoplankton species are stronger nutrient competitors than large phytoplankton species, but they are also more easily grazed. In contrast, evolution of large phytoplankton is often explained as a physical defense against grazing. Conceptually, this explanation is problematic, however, because zooplankton can coevolve larger size to counter this size-dependent escape from grazing. Here, we hypothesize that there is another advantage for the evolution of large phytoplankton size not so readily overcome: larger phytoplankton often provide lower nutritional quality for zooplankton. We investigate this hypothesis by analyzing an eco-evolutionary model that combines the ecological stoichiometry of phytoplankton-zooplankton interactions with coevolution of phytoplankton and zooplankton size. In our model, evolution of cell size modifies the nutrient uptake kinetics of phytoplankton according to known allometric relationships, which in turn affect the nutritional quality of phytoplankton. With this size-based mechanism, the model predicts that low grazing pressure or nonselective grazing by zooplankton favors evolution of small phytoplankton cells of high nutritional quality. In contrast, selective grazing for nutritious food favors evolution of large phytoplankton of low nutritional quality, which are preyed on by medium- to large-sized zooplankton. This size-dependent change in food quality may explain the commonly observed shift from dominance by small picophytoplankton in oligotrophic waters with low grazing pressure to large phytoplankton species in nutrient-rich waters with high grazing pressure.
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11
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Kozawa T, Sugitani K, Oehler DZ, House CH, Saito I, Watanabe T, Gotoh T. Early Archean planktonic mode of life: Implications from fluid dynamics of lenticular microfossils. GEOBIOLOGY 2019; 17:113-126. [PMID: 30378757 DOI: 10.1111/gbi.12319] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2018] [Revised: 08/31/2018] [Accepted: 09/11/2018] [Indexed: 06/08/2023]
Abstract
Lenticular, and commonly flanged, microfossils in 3.0-3.4 Ga sedimentary deposits in Western Australia and South Africa are unusually large (20-80 μm across), robust, and widespread in space and time. To gain insight into the ecology of these organisms, we performed simulations of fluid dynamics of virtual cells mimicking lenticular forms of variable sizes, oblateness, flange presence, and flange thickness. Results demonstrate that (a) the flange reduces sedimentation velocity, (b) this flange function works more effectively in larger cells, and (c) modest oblateness lowers sedimentation rate. These observations support interpretations that the lenticular microbes were planktonic-a lifestyle that could have been advantageous in an early Earth harsh environment including violent volcanic activities, repeated asteroid impacts, and relatively high UV-radiation. Although the robustness of these organisms could have provided additional protection on the early Earth, this architecture may have impeded a planktonic lifestyle by increasing cell density. However, our data suggest that this disadvantage could have been compensated by enlargement of cell volume, which could have enhanced the ability of the flange to slow sedimentation rate, especially if coupled with vacuolation. The results of this simulation study may help to explain the unique morphology and unusually large size of these Archean microfossils.
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Affiliation(s)
- Tomoki Kozawa
- Department of Physical Science and Engineering, Nagoya Institute of Technology, Nagoya, Japan
| | - Kenichiro Sugitani
- Graduate School of Environmental Studies, Nagoya University, Nagoya, Japan
| | | | - Christopher H House
- Department of Geosciences, The Pennsylvania University, University Park, Pennsylvania
| | - Izumi Saito
- Department of Physical Science and Engineering, Nagoya Institute of Technology, Nagoya, Japan
| | - Takeshi Watanabe
- Department of Physical Science and Engineering, Nagoya Institute of Technology, Nagoya, Japan
| | - Toshiyuki Gotoh
- Department of Physical Science and Engineering, Nagoya Institute of Technology, Nagoya, Japan
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12
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Beckmann A, Schaum CE, Hense I. Phytoplankton adaptation in ecosystem models. J Theor Biol 2019; 468:60-71. [PMID: 30796940 DOI: 10.1016/j.jtbi.2019.01.041] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2018] [Revised: 12/03/2018] [Accepted: 01/21/2019] [Indexed: 10/27/2022]
Abstract
We compare two different approaches to model adaptation of phytoplankton through trait value changes. Both consider mutation and selection (MuSe) but differ with respect to the underlying conceptual framework. The first one (MuSe-IBM) explicitly considers a population of individuals that are subject to random mutation during cell division. The second is a deterministic multi-compartment model (MuSe-MCM) that considers numerous genotypes of the population and where mutations are treated as a transfer of biomass between neighboring genotypes (i.e., a diffusion of characteristics in trait space). Focusing on the adaptation of optimal temperature, we show model results for different scenarios: a sudden change in environmental temperature, a seasonal variation and high frequency fluctuations. In addition, we investigate the effect of different shapes of thermal reaction norms as well as the role of alternating growth and resting phases on the adaptation process. For all cases, the differences between MuSe-IBM and MuSe-MCM are found to be negligible. Both models produce a number of well-known and plausible features. While the IBM has the advantage of including more mechanistic (i.e., probabilistic) processes, the MCM is much less computationally demanding and therefore suitable for implementation in three-dimensional ecosystem models.
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Affiliation(s)
| | | | - Inga Hense
- IMF, CEN, Universität Hamburg, Grosse Elbstrasse 133, Germany.
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13
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Pal D, Maiti SK. Heavy metal speciation, leaching and toxicity status of a tropical rain-fed river Damodar, India. ENVIRONMENTAL GEOCHEMISTRY AND HEALTH 2018; 40:2303-2324. [PMID: 29582263 DOI: 10.1007/s10653-018-0097-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/13/2017] [Accepted: 03/20/2018] [Indexed: 05/27/2023]
Abstract
Speciations of metals were assessed in a tropical rain-fed river, flowing through the highly economically important part of the India. The pattern of distribution of heavy metals (Cd, Co, Cr, Cu, Mn, Ni, Pb and Zn) were evaluated in water and sediment along with mineralogical characterization, changes with different water quality parameters and their respective health hazard to the local population along the Damodar River basin during pre-monsoon and post-monsoon seasons. The outcome of the speciation analysis using MINTEQ indicated that free metal ions, carbonate, chloride and sulfate ions were predominantly in anionic inorganic fractions, while in cationic inorganic fractions metal loads were negligible. Metals loads were higher in sediment phase than in the aqueous phase. The estimated values of Igeo in river sediment during both the seasons showed that most of the metals were found in the Igeo class 0-1 which represents unpolluted to moderately polluted sediment status. The result of partition coefficient indicated the strong retention capability of Cr, Pb, Co and Mn, while Cd, Zn, Cu and Ni have resilient mobility capacity. The mineralogical analysis of sediment samples indicated that in Damodar River, quartz, kaolinite and calcite minerals were dominantly present. The hazard index values of Cd, Co and Cr were > 1 in river water, which suggested potential health risk for the children. A combination of pragmatic, computational and statistical relationship between ionic species and fractions of metals represented a strong persuasion for identifying the alikeness among the different sites of the river.
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Affiliation(s)
- Divya Pal
- Department of Environmental Science and Engineering, Indian Institute of Technology (Indian School of Mines), Dhanbad, Jharkhand, 826004, India.
| | - Subodh Kumar Maiti
- Department of Environmental Science and Engineering, Indian Institute of Technology (Indian School of Mines), Dhanbad, Jharkhand, 826004, India
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Pu Z, Cortez MH, Jiang L. Predator-Prey Coevolution Drives Productivity-Richness Relationships in Planktonic Systems. Am Nat 2016; 189:28-42. [PMID: 28035895 DOI: 10.1086/689550] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
The relationship between environmental productivity and species richness often varies among empirical studies, and despite much research, simple explanations for this phenomenon remain elusive. We investigated how phytoplankton and zooplankton coevolution shapes productivity-richness relationships in both phytoplankton and zooplankton, using a simple nutrient-phytoplankton-zooplankton model that incorporates size-dependent metabolic rates summarized from empirical studies. The model allowed comparisons of evolved species richness across productivity levels and at different evolutionary times. Our results show that disruptive selection leads to evolutionary branching of phytoplankton and zooplankton. Both the time required for evolutionary branching and the number of evolved species in phytoplankton and zooplankton tend to increase with productivity, producing a transient unimodal or positive productivity-richness relationship but followed by a positive productivity-richness relationship for both groups over long enough evolutionary time. Our findings suggest that coevolution between phytoplankton and zooplankton can drive the two common forms (unimodal and positive) of productivity-richness relationships in nature.
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15
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Paleo-López R, Quintero-Galvis JF, Solano-Iguaran JJ, Sanchez-Salazar AM, Gaitan-Espitia JD, Nespolo RF. A phylogenetic analysis of macroevolutionary patterns in fermentative yeasts. Ecol Evol 2016; 6:3851-61. [PMID: 27516851 PMCID: PMC4972215 DOI: 10.1002/ece3.2097] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2015] [Revised: 03/02/2016] [Accepted: 03/03/2016] [Indexed: 02/06/2023] Open
Abstract
When novel sources of ecological opportunity are available, physiological innovations can trigger adaptive radiations. This could be the case of yeasts (Saccharomycotina), in which an evolutionary novelty is represented by the capacity to exploit simple sugars from fruits (fermentation). During adaptive radiations, diversification and morphological evolution are predicted to slow‐down after early bursts of diversification. Here, we performed the first comparative phylogenetic analysis in yeasts, testing the “early burst” prediction on species diversification and also on traits of putative ecological relevance (cell‐size and fermentation versatility). We found that speciation rates are constant during the time‐range we considered (ca., 150 millions of years). Phylogenetic signal of both traits was significant (but lower for cell‐size), suggesting that lineages resemble each other in trait‐values. Disparity analysis suggested accelerated evolution (diversification in trait values above Brownian Motion expectations) in cell‐size. We also found a significant phylogenetic regression between cell‐size and fermentation versatility (R2 = 0.10), which suggests correlated evolution between both traits. Overall, our results do not support the early burst prediction both in species and traits, but suggest a number of interesting evolutionary patterns, that warrant further exploration. For instance, we show that the Whole Genomic Duplication that affected a whole clade of yeasts, does not seems to have a statistically detectable phenotypic effect at our level of analysis. In this regard, further studies of fermentation under common‐garden conditions combined with comparative analyses are warranted.
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Affiliation(s)
- Rocío Paleo-López
- Instituto de Ciencias Ambientales y Evolutivas Universidad Austral de Chile Valdivia 5090000 Chile
| | - Julian F Quintero-Galvis
- Instituto de Ciencias Ambientales y Evolutivas Universidad Austral de Chile Valdivia 5090000 Chile
| | - Jaiber J Solano-Iguaran
- Instituto de Ciencias Ambientales y Evolutivas Universidad Austral de Chile Valdivia 5090000 Chile
| | - Angela M Sanchez-Salazar
- Instituto de Ciencias Ambientales y Evolutivas Universidad Austral de Chile Valdivia 5090000 Chile
| | - Juan D Gaitan-Espitia
- Instituto de Ciencias Ambientales y Evolutivas Universidad Austral de Chile Valdivia 5090000 Chile; CSIRO Oceans & Atmosphere GPO Box 1538 Hobart 7001 Tasmania Australia
| | - Roberto F Nespolo
- Instituto de Ciencias Ambientales y Evolutivas Universidad Austral de Chile Valdivia 5090000 Chile; Center of Applied Ecology and Sustainability (CAPES) Facultad de Ciencias Biológicas Universidad Católica de Chile Santiago 6513677 Chile
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16
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Gormley-Gallagher AM, Douglas RW, Rippey B. The Applicability of the Distribution Coefficient, KD, Based on Non-Aggregated Particulate Samples from Lakes with Low Suspended Solids Concentrations. PLoS One 2015. [PMID: 26200885 PMCID: PMC4511646 DOI: 10.1371/journal.pone.0133069] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
Abstract
Separate phases of metal partitioning behaviour in freshwater lakes that receive varying degrees of atmospheric contamination and have low concentrations of suspended solids were investigated to determine the applicability of the distribution coefficient, KD. Concentrations of Pb, Ni, Co, Cu, Cd, Cr, Hg and Mn were determined using a combination of filtration methods, bulk sample collection and digestion and Inductively Coupled Plasma-Mass Spectrometry (ICP-MS). Phytoplankton biomass, suspended solids concentrations and the organic content of the sediment were also analysed. By distinguishing between the phytoplankton and (inorganic) lake sediment, transient variations in KD were observed. Suspended solids concentrations over the 6-month sampling campaign showed no correlation with the KD (n = 15 for each metal, p > 0.05) for Mn (r2 = 0.0063), Cu (r2 = 0.0002, Cr (r2 = 0.021), Ni (r2 = 0.0023), Cd (r2 = 0.00001), Co (r2 = 0.096), Hg (r2 = 0.116) or Pb (r2 = 0.164). The results implied that colloidal matter had less opportunity to increase the dissolved (filter passing) fraction, which inhibited the spurious lowering of KD. The findings conform to the increasingly documented theory that the use of KD in modelling may mask true information on metal partitioning behaviour. The root mean square error of prediction between the directly measured total metal concentrations and those modelled based on the separate phase fractions were ± 3.40, 0.06, 0.02, 0.03, 0.44, 484.31, 80.97 and 0.1 μg/L for Pb, Cd, Mn, Cu, Hg, Ni, Cr and Co respectively. The magnitude of error suggests that the separate phase models for Mn and Cu can be used in distribution or partitioning models for these metals in lake water.
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Affiliation(s)
- Aine Marie Gormley-Gallagher
- School of Environmental Sciences, University of Ulster, Coleraine, N. Ireland, BT52 1SA, United Kingdom; School of Applied Sciences, Cranfield University, Bedfordshire, MK43 0AL, United Kingdom
| | - Richard William Douglas
- School of Environmental Sciences, University of Ulster, Coleraine, N. Ireland, BT52 1SA, United Kingdom
| | - Brian Rippey
- School of Environmental Sciences, University of Ulster, Coleraine, N. Ireland, BT52 1SA, United Kingdom
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17
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Roselli L, Basset A. Decoding size distribution patterns in marine and transitional water phytoplankton: from community to species level. PLoS One 2015; 10:e0127193. [PMID: 25974052 PMCID: PMC4431714 DOI: 10.1371/journal.pone.0127193] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2014] [Accepted: 04/12/2015] [Indexed: 11/29/2022] Open
Abstract
Understanding the mechanisms of phytoplankton community assembly is a fundamental issue of aquatic ecology. Here, we use field data from transitional (e.g. coastal lagoons) and coastal water environments to decode patterns of phytoplankton size distribution into organization and adaptive mechanisms. Transitional waters are characterized by higher resource availability and shallower well-mixed water column than coastal marine environments. Differences in physico-chemical regime between the two environments have been hypothesized to exert contrasting selective pressures on phytoplankton cell morphology (size and shape). We tested the hypothesis focusing on resource availability (nutrients and light) and mixed layer depth as ecological axes that define ecological niches of phytoplankton. We report fundamental differences in size distributions of marine and freshwater diatoms, with transitional water phytoplankton significantly smaller and with higher surface to volume ratio than marine species. Here, we hypothesize that mixing condition affecting size-dependent sinking may drive phytoplankton size and shape distributions. The interplay between shallow mixed layer depth and frequent and complete mixing of transitional waters may likely increase the competitive advantage of small phytoplankton limiting large cell fitness. The nutrient regime appears to explain the size distribution within both marine and transitional water environments, while it seem does not explain the pattern observed across the two environments. In addition, difference in light availability across the two environments appear do not explain the occurrence of asymmetric size distribution at each hierarchical level. We hypothesize that such competitive equilibria and adaptive strategies in resource exploitation may drive by organism’s behavior which exploring patch resources in transitional and marine phytoplankton communities.
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Affiliation(s)
- Leonilde Roselli
- Department of Biological and Environmental Sciences & Technologies, University of Salento, Lecce, Italy
- * E-mail:
| | - Alberto Basset
- Department of Biological and Environmental Sciences & Technologies, University of Salento, Lecce, Italy
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18
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Monds RD, Lee TK, Colavin A, Ursell T, Quan S, Cooper TF, Huang KC. Systematic perturbation of cytoskeletal function reveals a linear scaling relationship between cell geometry and fitness. Cell Rep 2014; 9:1528-37. [PMID: 25456141 DOI: 10.1016/j.celrep.2014.10.040] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2014] [Revised: 08/18/2014] [Accepted: 10/15/2014] [Indexed: 11/19/2022] Open
Abstract
Diversification of cell size is hypothesized to have occurred through a process of evolutionary optimization, but direct demonstrations of causal relationships between cell geometry and fitness are lacking. Here, we identify a mutation from a laboratory-evolved bacterium that dramatically increases cell size through cytoskeletal perturbation and confers a large fitness advantage. We engineer a library of cytoskeletal mutants of different sizes and show that fitness scales linearly with respect to cell size over a wide physiological range. Quantification of the growth rates of single cells during the exit from stationary phase reveals that transitions between "feast-or-famine" growth regimes are a key determinant of cell-size-dependent fitness effects. We also uncover environments that suppress the fitness advantage of larger cells, indicating that cell-size-dependent fitness effects are subject to both biophysical and metabolic constraints. Together, our results highlight laboratory-based evolution as a powerful framework for studying the quantitative relationships between morphology and fitness.
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Affiliation(s)
- Russell D Monds
- Bio-X Program, Stanford University, Stanford, CA 94305, USA; Department of Bioengineering, Stanford University, Stanford, CA 94305, USA.
| | - Timothy K Lee
- Department of Bioengineering, Stanford University, Stanford, CA 94305, USA
| | | | - Tristan Ursell
- Department of Bioengineering, Stanford University, Stanford, CA 94305, USA
| | - Selwyn Quan
- Bio-X Program, Stanford University, Stanford, CA 94305, USA
| | - Tim F Cooper
- Department of Biology and Biochemistry, University of Houston, Houston, TX 77204, USA
| | - Kerwyn Casey Huang
- Bio-X Program, Stanford University, Stanford, CA 94305, USA; Department of Bioengineering, Stanford University, Stanford, CA 94305, USA; Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, CA 94305, USA.
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19
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Segura AM, Kruk C, Calliari D, García-Rodriguez F, Conde D, Widdicombe CE, Fort H. Competition drives clumpy species coexistence in estuarine phytoplankton. Sci Rep 2013; 3:1037. [PMID: 23301158 PMCID: PMC3539148 DOI: 10.1038/srep01037] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2012] [Accepted: 12/12/2012] [Indexed: 11/11/2022] Open
Abstract
Understanding the mechanisms that maintain biodiversity is a fundamental problem in ecology. Competition is thought to reduce diversity, but hundreds of microbial aquatic primary producers species coexist and compete for a few essential resources (e.g., nutrients and light). Here, we show that resource competition is a plausible mechanism for explaining clumpy distribution on individual species volume (a proxy for the niche) of estuarine phytoplankton communities ranging from North America to South America and Europe, supporting the Emergent Neutrality hypothesis. Furthermore, such a clumpy distribution was also observed throughout the Holocene in diatoms from a sediment core. A Lotka-Volterra competition model predicted position in the niche axis and functional affiliation of dominant species within and among clumps. Results support the coexistence of functionally equivalent species in ecosystems and indicate that resource competition may be a key process to shape the size structure of estuarine phytoplankton, which in turn drives ecosystem functioning.
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Affiliation(s)
- A M Segura
- Universidad de la República, Facultad de Ciencias, Oceanography and Marine Ecology, Montevideo, Uruguay.
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20
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Examination of the role of detritus food quality, phytoplankton intracellular storage capacity, and zooplankton stoichiometry on planktonic dynamics. ECOL INFORM 2012. [DOI: 10.1016/j.ecoinf.2012.06.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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21
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Kerimoglu O, Straile D, Peeters F. Role of phytoplankton cell size on the competition for nutrients and light in incompletely mixed systems. J Theor Biol 2012; 300:330-43. [DOI: 10.1016/j.jtbi.2012.01.044] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2011] [Revised: 01/30/2012] [Accepted: 01/31/2012] [Indexed: 10/14/2022]
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22
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Close HG, Bovee R, Pearson A. Inverse carbon isotope patterns of lipids and kerogen record heterogeneous primary biomass. GEOBIOLOGY 2011; 9:250-265. [PMID: 21366841 DOI: 10.1111/j.1472-4669.2011.00273.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Throughout the Proterozoic δ(13)C values for preserved n-alkyl lipids are more positive than for syngenetic kerogen. This pattern is the inverse of biosynthetic expectations. It has been suggested that this isotopic inversion results from selective preservation of lipids from (13)C-enriched heterotrophic populations, while the bulk of kerogen derives from primary producers. Here, we formulate a degradation model to calculate the (13)C content of sedimentary total organic carbon and lipid. The model addresses two scenarios. The first scenario explores preferential preservation of heterotrophic lipid, thereby quantifying the existing hypothesis. In the second, we suggest that an inverse signature could be the result of prokaryotic phytoplankton contributing the majority of the total ecosystem biomass. Photosynthetic prokaryotes bearing a relative (13)C enrichment would contribute much of the resulting preserved lipids, while primary eukaryotic biomass would dominate the total organic carbon. We find that our hypothesis of a mixed primary producer community generates inverse isotopic patterns while placing far fewer requirements on specific degradation conditions. It also provides a possible explanation as to why there are large variations in the (13)C content of the isoprenoid lipids pristane and phytane relative to n-alkyl lipid, while the difference between n-alkyl lipid and kerogen is more constant. Our results suggest that the disappearance of the inverse (13)C signature in the late Ediacaran is a natural consequence of the fundamental shift to oceans in which export production has a higher ratio of eukaryotic biomass.
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Affiliation(s)
- H G Close
- Department of Earth & Planetary Sciences, Harvard University, Cambridge, MA, USA.
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23
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Unique coevolutionary dynamics in a predator-prey system. J Theor Biol 2011; 277:83-9. [PMID: 21354181 DOI: 10.1016/j.jtbi.2011.02.015] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2010] [Revised: 02/07/2011] [Accepted: 02/16/2011] [Indexed: 11/22/2022]
Abstract
In this paper, we study the predator-prey coevolutionary dynamics when a prey's defense and a predator's offense change in an adaptive manner, either by genetic evolution or phenotypic plasticity, or by behavioral choice. Results are: (1) The coevolutionary dynamics are more likely to be stable if the predator adapts faster than the prey. (2) The prey population size can be nearly constant but the predator population can show very large amplitude fluctuations. (3) Both populations may oscillate in antiphase. All of these are not observed when the handling time is short and the prey's density dependence is weak. (4) The population dynamics and the trait dynamics show resonance: the amplitude of the population fluctuation is the largest when the speed of adaptation is intermediate. These results may explain experimental studies with microorganisms.
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24
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Bruggeman J. A PHYLOGENETIC APPROACH TO THE ESTIMATION OF PHYTOPLANKTON TRAITS(1). JOURNAL OF PHYCOLOGY 2011; 47:52-65. [PMID: 27021710 DOI: 10.1111/j.1529-8817.2010.00946.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
The quantitative characterization of the ecology of individual phytoplankton taxa is essential for model resolution of many aspects of aquatic ecosystems. Existing literature cannot directly parameterize all phytoplankton taxa of interest, as many traits and taxa have not been sampled. However, valuable clues on the value of traits are found in the evolutionary history of species and in common correlations between traits. These two resources were exploited with an existing, statistically consistent method built upon evolutionary concepts. From a new data set with >700 observations on freshwater phytoplankton traits and a qualitative phytoplankton phylogeny, estimates were derived for the size, growth rate, phosphate affinity, and susceptibility to predation of 277 phytoplankton types, from evolutionary ancestors to present-day species. These estimates account simultaneously for phylogenetic relationships between types, as imposed by the phylogeny, and approximate power-law relationships (e.g., allometric scaling laws) between traits, as reconstructed from the data set. Results suggest that most phytoplankton traits are to some extent conserved in evolution: cross-validation demonstrated that the use of phylogenetic information significantly improves trait value estimates. By providing trait value estimates as well as uncertainties, these results could benefit most quantitative studies involving phytoplankton.
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Affiliation(s)
- Jorn Bruggeman
- Department of Earth Sciences, University of Oxford, South Parks Road, Oxford OX1 3AN, UK
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25
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Roy S, Sathyendranath S, Platt T. Retrieval of phytoplankton size from bio-optical measurements: theory and applications. J R Soc Interface 2010; 8:650-60. [PMID: 21084343 DOI: 10.1098/rsif.2010.0503] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The absorption coefficient of a substance distributed as discrete particles in suspension is less than that of the same material dissolved uniformly in a medium-a phenomenon commonly referred to as the flattening effect. The decrease in the absorption coefficient owing to flattening effect depends on the concentration of the absorbing pigment inside the particle, the specific absorption coefficient of the pigment within the particle, and on the diameter of the particle, if the particles are assumed to be spherical. For phytoplankton cells in the ocean, with diameters ranging from less than 1 µm to more than 100 µm, the flattening effect is variable, and sometimes pronounced, as has been well documented in the literature. Here, we demonstrate how the in vivo absorption coefficient of phytoplankton cells per unit concentration of its major pigment, chlorophyll a, can be used to determine the average cell size of the phytoplankton population. Sensitivity analyses are carried out to evaluate the errors in the estimated diameter owing to potential errors in the model assumptions. Cell sizes computed for field samples using the model are compared qualitatively with indirect estimates of size classes derived from high performance liquid chromatography data. Also, the results are compared quantitatively against measurements of cell size in laboratory cultures. The method developed is easy-to-apply as an operational tool for in situ observations, and has the potential for application to remote sensing of ocean colour data.
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Affiliation(s)
- Shovonlal Roy
- Department of Oceanography, Dalhousie University, Halifax, Nova Scotia, Canada B3H 4J1.
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26
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Butterfield NJ. Macroevolutionary turnover through the Ediacaran transition: ecological and biogeochemical implications. ACTA ACUST UNITED AC 2009. [DOI: 10.1144/sp326.3] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
AbstractEcological and evolutionary principles are often context-dependent, particularly where the context is biologically defined. Organ-grade animals (eumetazoans) are particularly powerful contextual agents, with a unique capacity to drive escalatory co-evolution and build multi-tiered food-webs. The evolution of eumetazoans through the Ediacaran and early Cambrian fundamentally altered macroecological and macroevolutionary dynamics, including the structure and function of the marine carbon cycle. Pelagic eumetazoans can be held responsible for driving the evolution of relatively large eukaryotic phytoplankton, thereby shifting the system from a turbid, stratified, cyanobacteria-dominated stable state to the clear-water, well-oxygenated, algae-dominated condition typical of the Phanerozoic. Intermittent return to the pre-Ediacaran state during Phanerozoic extinctions and oceanic anoxic events suggests that the widespread anoxia detected in pre-Ediacaran deep-marine sequences may be a consequence of this alternate biological pump rather than a reflection of fundamentally lower levels of atmospheric oxygen. The transition between the pre- and post-Ediacaran states is also associated with the oldest commercially exploitable hydrocarbons, a possible by-product of invading animals and their top-down impact on the biological pump.
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Affiliation(s)
- Nicholas J. Butterfield
- Department of Earth Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EQ, UK (e-mail: )
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27
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The presence of generalist plant pathogens might not explain the long-term coexistence of plant species. J Theor Biol 2009; 257:446-53. [DOI: 10.1016/j.jtbi.2008.11.020] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2008] [Revised: 11/07/2008] [Accepted: 11/26/2008] [Indexed: 11/17/2022]
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28
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29
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Menge DNL, Weitz JS. Dangerous nutrients: evolution of phytoplankton resource uptake subject to virus attack. J Theor Biol 2008; 257:104-15. [PMID: 19068219 DOI: 10.1016/j.jtbi.2008.10.032] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2008] [Revised: 10/03/2008] [Accepted: 10/21/2008] [Indexed: 11/15/2022]
Abstract
Phytoplankton need multiple resources to grow and reproduce (such as nitrogen, phosphorus, and iron), but the receptors through which they acquire resources are, in many cases, the same channels through which viruses attack. Therefore, phytoplankton can face a bottom-up vs. top-down tradeoff in receptor allocation: Optimize resource uptake or minimize virus attack? We investigate this top-down vs. bottom-up tradeoff using an evolutionary ecology model of multiple essential resources, specialist viruses that attack through the resource receptors, and a phytoplankton population that can evolve to alter the fraction of receptors used for each resource/virus type. Without viruses present the singular continuously stable strategy is to allocate receptors such that resources are co-limiting, which also minimizes the equilibrium concentrations of both resources. Only one virus type can be present at equilibrium (because phytoplankton, in this model, are a single resource for viruses), and when a virus type is present, it controls the equilibrium phytoplankton population size. Despite this top-down control on equilibrium densities, bottom-up control determines the evolutionary outcome. Regardless of which virus type is present, the allocation strategy that yields co-limitation between the two resources is continuously stable. This is true even when the virus type attacking through the limiting resource channel is present, even though selection for co-limitation in this case decreases the equilibrium phytoplankton population and does not decrease the equilibrium concentration of the limiting resource. Therefore, although moving toward co-limitation and decreasing the equilibrium concentration of the limiting resource often co-occur in models, it is co-limitation, and not necessarily the lowest equilibrium concentration of the limiting resource, that is the result of selection. This result adds to the growing body of literature suggesting that co-limitation at equilibrium is a winning strategy.
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Affiliation(s)
- Duncan N L Menge
- Department of Ecology and Evolutionary Biology, Princeton University, USA.
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30
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Strauss SY, Lau JA, Schoener TW, Tiffin P. Evolution in ecological field experiments: implications for effect size. Ecol Lett 2008; 11:199-207. [DOI: 10.1111/j.1461-0248.2007.01128.x] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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31
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Yoshiyama K, Klausmeier CA. Optimal cell size for resource uptake in fluids: a new facet of resource competition. Am Nat 2008; 171:59-70. [PMID: 18171151 DOI: 10.1086/523950] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Planktonic microorganisms are affected by various size-dependent processes both from the bottom up and from the top down. We developed a simple resource-consumer model to explore how size-dependent resource uptake and resource loss influence the growth of, and competition between, planktonic microorganisms. We considered three steps of resource uptake: diffusive transport of resource molecules, uptake by membrane transporters, and cellular enzymatic catalysis, and we investigated optimal cell size when one, two, or three of those steps limit resource uptake. Optimal cell size depends negatively on the size of resource molecules when resource uptake is limited by diffusive transport and membrane uptake. When competing for two resources of different molecular sizes, two different-sized consumers can coexist if the inputs of resources and sizes of consumers are correctly chosen. The model suggests that mixtures of various-sized resources can promote coexistence and size diversity of microorganisms even if the availability of one element, such as carbon, nitrogen, or phosphorus, limits the whole community. Model predictions include that bacteria grown on maltose or polysaccharides should be smaller compared with those grown on glucose under carbon limitation. Our results suggest that size of resource molecules can be an important factor in microbial resource competition in aquatic environments.
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Affiliation(s)
- Kohei Yoshiyama
- W. K. Kellogg Biological Station, Michigan State University, Hickory Corners, Michigan 49060, USA.
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32
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Abstract
We propose a scaled version of the Rosenzweig-MacArthur model using both Type I and Type II functional responses that incorporates the size dependence of interaction rates. Our aim is to link the energetic needs of organisms with the dynamics of interacting populations, for which survival is a result of a game-theoretic struggle for existence. We solve the scaled model of predator-prey dynamics and predict population level characteristics such as the scaling of coexistence size ranges and the optimal predator-prey size ratio. For a broad class of such models, the optimal predator-prey size ratio given available prey of a fixed size is constant. We also demonstrate how scaling predictions of prey density differ under resource limitation vs. predator drawdown. Finally, we show how evolution of predator size can destabilize population dynamics, compare scaling of predator-prey cycles to previous work, as well as discuss possible extensions of the model to multispecies communities.
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