Lake warming favours small-sized planktonic diatom species

Proceedings of the Royal Society B Biological Sciences, Journal Year: 2008, Volume and Issue: 276(1656), P. 427 - 435

Published: Sept. 23, 2008

Diatoms contribute to a substantial portion of primary production in the oceans and many lakes. Owing their relatively heavy cell walls high nutrient requirements, planktonic diatoms are expected decrease with climate warming because reduced redistribution increasing sinking velocities. Using historical dataset, this study shows that were able maintain biovolume stratification Lake Tahoe over last decades; however, diatom community structure changed. Increased nitrogen phosphorus ratios selected for small-celled diatoms, particularly within Cyclotella genus. An empirical model showed shift phytoplankton species composition size was consistent different depth strata, indicating altered concentrations not responsible change. The increase sufficient average thus velocity, which strongly influences energy transfer through food web carbon cycling. Our results show diverse group small-sized surface area volume ratio adapt mixing intensity, supporting hypotheses abiotic drivers affect communities warmer favours cells.

Language: Английский

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Allometric scaling and taxonomic variation in nutrient utilization traits and maximum growth rate of phytoplankton

Limnology and Oceanography, Journal Year: 2012, Volume and Issue: 57(2), P. 554 - 566

Published: March 1, 2012

Nutrient utilization traits can be used to link the ecophysiology of phytoplankton population dynamic models and structure communities across environmental gradients. Here we analyze a comprehensive literature compilation four traits: maximum nutrient uptake rate; half‐saturation constant for uptake; minimum subsistence quota, measured nitrate phosphate; growth rate. We also use these two composite traits, affinity scaled affinity. All tend increase with cell volume, except rate, which decline volume. Most scaling relationships are same freshwater marine species, although important differences exist. differ on average between major taxa, but between‐taxon variation is nearly always due in There some evidence between‐trait correlations that could constrain trait evolution, difficult disentangle from correlation driven by These results should enhance parameterization size or taxonomic group physiological communities.

Language: Английский

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Trait-based approaches for understanding microbial biodiversity and ecosystem functioning

Frontiers in Microbiology, Journal Year: 2014, Volume and Issue: 5

Published: May 27, 2014

In ecology, biodiversity-ecosystem functioning (BEF) research has seen a shift in perspective from taxonomy to function the last two decades, with successful application of trait-based approaches. This offers opportunities for deeper mechanistic understanding role biodiversity maintaining multiple ecosystem processes and services. this paper, we highlight studies that have focused on BEF microbial communities an emphasis integrating approaches ecology. doing so, explore some inherent challenges using systems. For example, biologists characterize gene phylogenies are often unable resolve functional traits. Additionally, experimental designs existing inadequate unravel relationships. We argue combining eco-physiological contemporary molecular tools framework can reinforce our ability link diversity processes. conclude such promising increase relationships thus generating systematic principles ecology more generally

Language: Английский

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A trait-based framework for predicting when and where microbial adaptation to climate change will affect ecosystem functioning

Biogeochemistry, Journal Year: 2011, Volume and Issue: 109(1-3), P. 35 - 47

Published: Sept. 3, 2011

Language: Английский

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Warming alters the size spectrum and shifts the distribution of biomass in freshwater ecosystems

Global Change Biology, Journal Year: 2010, Volume and Issue: 17(4), P. 1681 - 1694

Published: Aug. 29, 2010

Organism size is one of the key determinants community structure, and its relationship with abundance can describe how biomass partitioned among biota within an ecosystem. An outdoor freshwater mesocosm experiment was used to determine warming of∼4 °C would affect size, taxonomic structure planktonic communities. Warming increased steepness spectrum by increasing prevalence small organisms, primarily phytoplankton assemblage it also reduced mean maximum approximately order magnitude. The observed shifts in were reflected changes composition, though zooplankton composition unaffected warming. Furthermore, total biomass, although unaffected. This resulted increase ratio warmed mesocosms, which could be explained faster turnover assemblages. Overall, shifted distribution towards smaller individuals rapid low standing resulting a reorganization food webs. These results indicate future environmental may have profound effects on functioning aquatic communities ecosystems.

Language: Английский

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Mixotrophic cyanobacteria and microalgae as distinctive biological agents for organic pollutant degradation

Environment International, Journal Year: 2012, Volume and Issue: 51, P. 59 - 72

Published: Nov. 28, 2012

Millions of natural and synthetic organic chemical substances are present in both soil aquatic environments. Toxicity and/or persistence determine the polluting principle these substances. The biological responses to pollutants include accumulation degradation. environments with perceptible from dwindling degradative abilities microorganisms. Among different members, cyanobacteria microalgae highly adaptive through many eons, can grow autotrophically, heterotrophically or mixotrophically. Mixotrophy provide competitive advantages over bacteria fungi degrading pollutants. Laboratory culturing strict phototrophic algae has limited realization their potential as bioremediation agents. In assemblages, mixotrophic contribute sequestration carbon, which is otherwise emitted carbon dioxide atmosphere under heterotrophic conditions by other organisms. Molecular methods metabolic genomic information will help not only identification selection species capabilities degrade but also monitoring efficiency remediation efforts field conditions. These organisms relatively easier for genetic engineering desirable traits. This review presents a new premise literature that distinctive agents sequester environment.

Language: Английский

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Unimodal size scaling of phytoplankton growth and the size dependence of nutrient uptake and use

Ecology Letters, Journal Year: 2012, Volume and Issue: 16(3), P. 371 - 379

Published: Dec. 20, 2012

Abstract Phytoplankton size structure is key for the ecology and biogeochemistry of pelagic ecosystems, but relationship between cell maximum growth rate (μ max ) not yet well understood. We used cultures 22 species marine phytoplankton from five phyla, ranging 0.1 to 10 6 μm 3 in volume (V ), determine experimentally dependence growth, metabolic rate, elemental stoichiometry nutrient uptake. show that both μ carbon‐specific photosynthesis peak at intermediate sizes. Maximum nitrogen uptake ( V maxN scales isometrically with , whereas minimum quota as 0.84 . Large cells thus possess high ability take up nitrogen, relative their requirements, large storage capacity, limited by conversion nutrients into biomass. Small similar volume‐specific compared larger counterparts, have higher requirements. suggest unimodal scaling arises taxon‐independent, size‐related constraints uptake, requirement assimilation.

Language: Английский

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A size‐structured food‐web model for the global ocean

Limnology and Oceanography, Journal Year: 2012, Volume and Issue: 57(6), P. 1877 - 1891

Published: Nov. 1, 2012

We present a model of diverse phytoplankton and zooplankton populations embedded in global ocean circulation model. Physiological ecological traits the organisms are constrained by relationships with cell size. The qualitatively reproduces distributions nutrients, biomass, primary productivity, captures power‐law relationship between size numerical density, which has realistic slopes −1.3 −0.8. use to explore structure marine ecosystems, highlighting importance both nutrient grazer controls. suggests that : (Z P) biomass ratios may vary from an order 0.1 oligotrophic gyres 10 upwelling high‐latitude regions. Global estimates strength bottom‐up top‐down controls within plankton classes suggest these large‐scale gradients Z P driven shift strong bottom‐up, limitation dominance top‐down, grazing more productive

Language: Английский

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Environmental control of open‐ocean phytoplankton groups: Now and in the future

Limnology and Oceanography, Journal Year: 2010, Volume and Issue: 55(3), P. 1353 - 1376

Published: April 13, 2010

Climate change will alter concurrently many environmental factors that exert control over oceanic phytoplankton. Recent laboratory culture work, shipboard experiments, and field surveys reveal remaining unknowns about the bottom‐up controls for five globally important algal groups. Increasing uncertainties exist, respectively, picocyanobacteria, diatoms, Phaeocystis spp., N 2 ‐fixing cyanobacteria, coccolithophores. This missing information current hinder progress in modeling how these phytoplankton be influenced by climate change. A review of conceptual approaches used to elucidate relationship between dominance, from Margalef's mandala functional traits, uncovered limitations regarding their application climate‐change scenarios. For example, previous have insufficient scope or dimensions take into account confounding effects synergistic antagonistic interactions multiple variables. new approach is needed considers all different properties altered while at same time permitting a subset most significant specific group isolated evaluated factorial matrix perturbation experiments. We advocate three interlinked approaches, including clusters incorporate (temperature, CO , light, nutrients, trace metals), which both present‐day floristics By carefully linking holistic reductionist experimental design, future responses open‐ocean groups complex, rapidly changing environment can better predicted.

Language: Английский

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Towards an integration of ecological stoichiometry and the metabolic theory of ecology to better understand nutrient cycling

Ecology Letters, Journal Year: 2009, Volume and Issue: 12(5), P. 369 - 384

Published: March 27, 2009

Ecologists have long recognized that species are sustained by the flux, storage and turnover of two biological currencies: energy, which fuels metabolism materials (i.e. chemical elements), used to construct biomass. Ecological theories often describe dynamics populations, communities ecosystems in terms either energy (e.g. population-dynamics theory) or resource-competition theory). These classes theory been formulated using different assumptions, yield distinct, but complementary predictions for same similar phenomena. For example, energy-based equation von Bertalanffy nutrient-based Droop both growth. Yet, there is relatively little theoretical understanding how these distinct theory, currencies they use, interrelated. Here, we begin address this issue integrating models concepts from rapidly developing theories, metabolic ecology ecological stoichiometry theory. We show combining recently published data along with new formulations, leads novel on apply animals, plants unicells. The results presented here highlight potential a more general explicitly relates energetics individuals, subcellular structures processes. conclude discussing basic applied implications such prospects challenges further development.

Language: Английский

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