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Larsen S, Karaus U, Claret C, Sporka F, Hamerlík L, Tockner K. Flooding and hydrologic connectivity modulate community assembly in a dynamic river-floodplain ecosystem. PLoS One 2019; 14:e0213227. [PMID: 30978198 PMCID: PMC6461263 DOI: 10.1371/journal.pone.0213227] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2019] [Accepted: 04/02/2019] [Indexed: 11/24/2022] Open
Abstract
Braided river floodplains are highly dynamic ecosystems, where aquatic communities are strongly regulated by the hydrologic regime. So far, however, understanding of how flow variation influences assembly mechanisms remains limited. We collected benthic chironomids and oligochaetes over a year across a lateral connectivity gradient in the semi-natural Tagliamento River (Italy). Four bankfull flood events occurred during the study, allowing the assessment of how flooding and hydrologic connectivity mediate the balance between stochastic and deterministic community assembly. While invertebrate density and richness were positively correlated with connectivity, diversity patterns showed no significant correlation. Species turnover through time increased with decreasing connectivity. Contrary to expectations, hydrologic connectivity did not influence the response of community metrics (e.g. diversity, density) to floods. Invertebrate composition was weakly related to connectivity, but changed predictably in response to floods. Multivariate ordinations showed that faunal composition diverged across the waterbodies during stable periods, reflecting differential species sorting across the lateral gradient, but converged again after floods. Stable hydrological periods allowed communities to assemble deterministically with prevalence of non-random beta-diversity and co-occurrence patterns and larger proportion of compositional variation explained by local abiotic features. These signals of deterministic processes declined after flooding events. This occurred despite no apparent evidence of flood-induced homogenisation of habitat conditions. This study is among the first to examine the annual dynamic of aquatic assemblages across a hydrologic connectivity gradient in a natural floodplain. Results highlight how biodiversity can exhibit complex relations with hydrologic connectivity. However, appraisal of the assembly mechanisms through time indicated that flooding shifted the balance from deterministic species sorting across floodplain habitats, towards stochastic processes related to organisms redistribution and the likely resetting of assembly to earlier stages.
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Affiliation(s)
- Stefano Larsen
- University of Trento, Department of Civil, Environmental and Mechanical Engineering, Trento, Italy
- * E-mail:
| | - Ute Karaus
- Institute of Civil, Environmental and Geomatic Engineering, ETH Zürich, Zurich, Switzerland
| | - Cecile Claret
- Institut Méditerranéen de Biodiversité et d’Ecologie Marine et Continentale (IMBE), Aix-Marseille Université, France
| | - Ferdinand Sporka
- Institute of Zoology, Slovak Academy of Sciences, Bratislava, Slovakia
| | - Ladislav Hamerlík
- Matej Bel University, Faculty of Natural Sciences, Banksa Bystrica, Slovakia
| | - Klement Tockner
- Austrian Science Fund FWF, Vienna, Austria
- Leibniz-Institute of Freshwater Ecology and Inland Fisheries, Berlin, Germany
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Pound KL, Lawrence GB, Passy SI. Beta diversity response to stress severity and heterogeneity in sensitive versus tolerant stream diatoms. DIVERS DISTRIB 2018. [DOI: 10.1111/ddi.12865] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Affiliation(s)
- Katrina L. Pound
- Department of Biology University of Texas at Arlington Arlington Texas
| | | | - Sophia I. Passy
- Department of Biology University of Texas at Arlington Arlington Texas
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Jones AA, Bennett PC. Mineral Ecology: Surface Specific Colonization and Geochemical Drivers of Biofilm Accumulation, Composition, and Phylogeny. Front Microbiol 2017; 8:491. [PMID: 28400754 PMCID: PMC5368280 DOI: 10.3389/fmicb.2017.00491] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2016] [Accepted: 03/09/2017] [Indexed: 01/30/2023] Open
Abstract
This study tests the hypothesis that surface composition influences microbial community structure and growth of biofilms. We used laboratory biofilm reactors (inoculated with a diverse subsurface community) to explore the phylogenetic and taxonomic variability in microbial communities as a function of surface type (carbonate, silicate, aluminosilicate), media pH, and carbon and phosphate availability. Using high-throughput pyrosequencing, we found that surface type significantly controlled ~70–90% of the variance in phylogenetic diversity regardless of environmental pressures. Consistent patterns also emerged in the taxonomy of specific guilds (sulfur-oxidizers/reducers, Gram-positives, acidophiles) due to variations in media chemistry. Media phosphate availability was a key property associated with variation in phylogeny and taxonomy of whole reactors and was negatively correlated with biofilm accumulation and α-diversity (species richness and evenness). However, mineral-bound phosphate limitations were correlated with less biofilm. Carbon added to the media was correlated with a significant increase in biofilm accumulation and overall α-diversity. Additionally, planktonic communities were phylogenetically distant from those in biofilms. All treatments harbored structurally (taxonomically and phylogenetically) distinct microbial communities. Selective advantages within each treatment encouraged growth and revealed the presence of hundreds of additional operational taxonomix units (OTU), representing distinct consortiums of microorganisms. Ultimately, these results provide evidence that mineral/rock composition significantly influences microbial community structure, diversity, membership, phylogenetic variability, and biofilm growth in subsurface communities.
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Affiliation(s)
- Aaron A Jones
- Department of Geological Sciences, University of Texas at Austin Austin, TX, USA
| | - Philip C Bennett
- Department of Geological Sciences, University of Texas at Austin Austin, TX, USA
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Bayona Y, Roucaute M, Cailleaud K, Lagadic L, Bassères A, Caquet T. Effect of thiram and of a hydrocarbon mixture on freshwater macroinvertebrate communities in outdoor stream and pond mesocosms: I. Study design, chemicals fate and structural responses. ECOTOXICOLOGY (LONDON, ENGLAND) 2015; 24:1976-1995. [PMID: 26385344 DOI: 10.1007/s10646-015-1534-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 08/31/2015] [Indexed: 06/05/2023]
Abstract
Higher-tier ecological risk assessment (ERA) in mesocosms is commonly performed in lotic or lentic experimental systems. These systems differ in their physico-chemical and hydrological properties, leading to differences in chemical fate, community characteristics and potential recovery. This raises the issue of the relevance and sensitivity of community-level endpoints in different types of mesocosms. In this study, macroinvertebrate abundance and biomass estimates were used to assess the effects of a dithiocarbamate fungicide, thiram (35 and 170 µg l(-1)), and a petroleum middle distillate (PMD; 0.01, 0.4, 2 and 20 mg l(-1)) in outdoor stream and pond mesocosms. Streams were continuously treated during 3 weeks followed by a 2-month long post-treatment period. Ponds were treated weekly for 4 weeks, followed by a 10-month long post-treatment period. Taxonomic structure of macroinvertebrate communities was characterized using the α, β and γ components of taxa richness, Shannon and Gini-Simpson indices. Computations were based either on abundance or biomass data. Results clearly highlighted that the effects of chemicals depended on the exposure regime (for thiram) and type of system (for the PMD). Causes of the differences between streams and ponds in the magnitude and nature of effects include differential sensitivity of taxa dwelling in lentic and lotic systems and the influence of hydrology (e.g., drift from upstream) and mesocosm connectivity on recovery dynamics. This study also showed complementarities in the use of both types of mesocosms to improve the characterization of chemical effects on communities in ERA.
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Affiliation(s)
- Yannick Bayona
- INRA, UMR985 Écologie et Santé des Écosystèmes, Équipe Écotoxicologie et Qualité des Milieux Aquatiques, Agrocampus Ouest, 65 rue de Saint Brieuc, CS 84215, 35042, Rennes, France.
- Service Environnement, TOTAL, Pôle d'Etude et de Recherche de Lacq RN 117, BP 47, 64170, Lacq, France.
| | - Marc Roucaute
- INRA, UMR985 Écologie et Santé des Écosystèmes, Équipe Écotoxicologie et Qualité des Milieux Aquatiques, Agrocampus Ouest, 65 rue de Saint Brieuc, CS 84215, 35042, Rennes, France
| | - Kevin Cailleaud
- Service Environnement, TOTAL, Pôle d'Etude et de Recherche de Lacq RN 117, BP 47, 64170, Lacq, France
| | - Laurent Lagadic
- INRA, UMR985 Écologie et Santé des Écosystèmes, Équipe Écotoxicologie et Qualité des Milieux Aquatiques, Agrocampus Ouest, 65 rue de Saint Brieuc, CS 84215, 35042, Rennes, France
| | - Anne Bassères
- Service Environnement, TOTAL, Pôle d'Etude et de Recherche de Lacq RN 117, BP 47, 64170, Lacq, France
| | - Thierry Caquet
- INRA, UMR985 Écologie et Santé des Écosystèmes, Équipe Écotoxicologie et Qualité des Milieux Aquatiques, Agrocampus Ouest, 65 rue de Saint Brieuc, CS 84215, 35042, Rennes, France
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Cole JK, Hutchison JR, Renslow RS, Kim YM, Chrisler WB, Engelmann HE, Dohnalkova AC, Hu D, Metz TO, Fredrickson JK, Lindemann SR. Phototrophic biofilm assembly in microbial-mat-derived unicyanobacterial consortia: model systems for the study of autotroph-heterotroph interactions. Front Microbiol 2014; 5:109. [PMID: 24778628 PMCID: PMC3985010 DOI: 10.3389/fmicb.2014.00109] [Citation(s) in RCA: 84] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2013] [Accepted: 03/04/2014] [Indexed: 11/24/2022] Open
Abstract
Microbial autotroph-heterotroph interactions influence biogeochemical cycles on a global scale, but the diversity and complexity of natural systems and their intractability to in situ manipulation make it challenging to elucidate the principles governing these interactions. The study of assembling phototrophic biofilm communities provides a robust means to identify such interactions and evaluate their contributions to the recruitment and maintenance of phylogenetic and functional diversity over time. To examine primary succession in phototrophic communities, we isolated two unicyanobacterial consortia from the microbial mat in Hot Lake, Washington, characterizing the membership and metabolic function of each consortium. We then analyzed the spatial structures and quantified the community compositions of their assembling biofilms. The consortia retained the same suite of heterotrophic species, identified as abundant members of the mat and assigned to Alphaproteobacteria, Gammaproteobacteria, and Bacteroidetes. Autotroph growth rates dominated early in assembly, yielding to increasing heterotroph growth rates late in succession. The two consortia exhibited similar assembly patterns, with increasing relative abundances of members from Bacteroidetes and Alphaproteobacteria concurrent with decreasing relative abundances of those from Gammaproteobacteria. Despite these similarities at higher taxonomic levels, the relative abundances of individual heterotrophic species were substantially different in the developing consortial biofilms. This suggests that, although similar niches are created by the cyanobacterial metabolisms, the resulting webs of autotroph-heterotroph and heterotroph-heterotroph interactions are specific to each primary producer. The relative simplicity and tractability of the Hot Lake unicyanobacterial consortia make them useful model systems for deciphering interspecies interactions and assembly principles relevant to natural microbial communities.
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Affiliation(s)
- Jessica K Cole
- Biological Sciences Division, Fundamental and Computational Sciences Directorate, Pacific Northwest National Laboratory Richland, WA, USA
| | - Janine R Hutchison
- Chemical, Biological, and Physical Sciences Division, National Security Directorate, Pacific Northwest National Laboratory Richland, WA, USA
| | - Ryan S Renslow
- Scientific Resources Division, William R. Wiley Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory Richland, WA, USA
| | - Young-Mo Kim
- Biological Sciences Division, Fundamental and Computational Sciences Directorate, Pacific Northwest National Laboratory Richland, WA, USA
| | - William B Chrisler
- Biological Sciences Division, Fundamental and Computational Sciences Directorate, Pacific Northwest National Laboratory Richland, WA, USA
| | - Heather E Engelmann
- Chemical, Biological, and Physical Sciences Division, National Security Directorate, Pacific Northwest National Laboratory Richland, WA, USA
| | - Alice C Dohnalkova
- Scientific Resources Division, William R. Wiley Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory Richland, WA, USA
| | - Dehong Hu
- Scientific Resources Division, William R. Wiley Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory Richland, WA, USA
| | - Thomas O Metz
- Biological Sciences Division, Fundamental and Computational Sciences Directorate, Pacific Northwest National Laboratory Richland, WA, USA
| | - Jim K Fredrickson
- Biological Sciences Division, Fundamental and Computational Sciences Directorate, Pacific Northwest National Laboratory Richland, WA, USA
| | - Stephen R Lindemann
- Biological Sciences Division, Fundamental and Computational Sciences Directorate, Pacific Northwest National Laboratory Richland, WA, USA
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Aerobic biofilms grown from Athabasca watershed sediments are inhibited by increasing concentrations of bituminous compounds. Appl Environ Microbiol 2013; 79:7398-412. [PMID: 24056457 DOI: 10.1128/aem.02216-13] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Sediments from the Athabasca River and its tributaries naturally contain bitumen at various concentrations, but the impacts of this variation on the ecology of the river are unknown. Here, we used controlled rotating biofilm reactors in which we recirculated diluted sediments containing various concentrations of bituminous compounds taken from the Athabasca River and three tributaries. Biofilms exposed to sediments having low and high concentrations of bituminous compounds were compared. The latter were 29% thinner, had a different extracellular polysaccharide composition, 67% less bacterial biomass per μm2, 68% less cyanobacterial biomass per μm2, 64% less algal biomass per μm2, 13% fewer protozoa per cm2, were 21% less productive, and had a 33% reduced content in chlorophyll a per mm2 and a 20% reduction in the expression of photosynthetic genes, but they had a 23% increase in the expression of aromatic hydrocarbon degradation genes. Within the Bacteria, differences in community composition were also observed, with relatively more Alphaproteobacteria and Betaproteobacteria and less Cyanobacteria, Bacteroidetes, and Firmicutes in biofilms exposed to high concentrations of bituminous compounds. Altogether, our results suggest that biofilms that develop in the presence of higher concentrations of bituminous compounds are less productive and have lower biomass, linked to a decrease in the activities and abundance of photosynthetic organisms likely due to inhibitory effects. However, within this general inhibition, some specific microbial taxa and functional genes are stimulated because they are less sensitive to the inhibitory effects of bituminous compounds or can degrade and utilize some bitumen-associated compounds.
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