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Stewart ECD, Bribiesca‐Contreras G, Taboada S, Wiklund H, Ravara A, Pape E, De Smet B, Neal L, Cunha MR, Jones DOB, Smith CR, Glover AG, Dahlgren TG. Biodiversity, biogeography, and connectivity of polychaetes in the world's largest marine minerals exploration frontier. DIVERS DISTRIB 2023. [DOI: 10.1111/ddi.13690] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/30/2023] Open
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2
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Kokate PP, Bales E, Joyner D, Hazen TC, Techtmann SM. Biogeographic patterns in populations of marine Pseudoalteromonas atlantica isolates. FEMS Microbiol Lett 2023; 370:fnad081. [PMID: 37573136 DOI: 10.1093/femsle/fnad081] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2023] [Revised: 07/14/2023] [Accepted: 08/11/2023] [Indexed: 08/14/2023] Open
Abstract
Intra-specific genomic diversity is well documented in microbes. The question, however, remains whether natural selection or neutral evolution is the major contributor to this diversity. We undertook this study to estimate genomic diversity in Pseudoalteromonas atlantica populations and whether the diversity, if present, could be attributed to environmental factors or distance effects. We isolated and sequenced twenty-three strains of P. atlantica from three geographically distant deep marine basins and performed comparative genomic analyses to study the genomic diversity of populations among these basins. Average nucleotide identity followed a strictly geographical pattern. In two out of three locations, the strains within the location exhibited >99.5% identity, whereas, among locations, the strains showed <98.11% identity. Phylogenetic and pan-genome analysis also reflected the biogeographical separation of the strains. Strains from the same location shared many accessory genes and clustered closely on the phylogenetic tree. Phenotypic diversity between populations was studied in ten out of twenty-three strains testing carbon and nitrogen source utilization and osmotolerance. A genetic basis for phenotypic diversity could be established in most cases but was apparently not influenced by local environmental conditions. Our study suggests that neutral evolution may have a substantial role in the biodiversity of P. atlantica.
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Affiliation(s)
- Prajakta P Kokate
- Department of Biological Sciences, Michigan Technological University, Houghton, MI 49931, United States
| | - Erika Bales
- Department of Microbiology, University of Tennessee Knoxville, Knoxville, TN 37996, United States
| | - Dominique Joyner
- Department of Civil and Environmental Engineering, University of Tennessee Knoxville, Knoxville, TN 37996, United States
| | - Terry C Hazen
- Department of Microbiology, University of Tennessee Knoxville, Knoxville, TN 37996, United States
- Department of Civil and Environmental Engineering, University of Tennessee Knoxville, Knoxville, TN 37996, United States
| | - Stephen M Techtmann
- Department of Biological Sciences, Michigan Technological University, Houghton, MI 49931, United States
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3
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Bryant SRD, McClain CR. Functional space expansion driven by transitions between energetically advantageous traits in the deep sea. Proc Biol Sci 2022; 289:20221302. [PMID: 36382521 PMCID: PMC9667370 DOI: 10.1098/rspb.2022.1302] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2022] [Accepted: 10/25/2022] [Indexed: 12/02/2023] Open
Abstract
Climate change is shifting community structure and biodiversity on a global scale, in part due to alterations of chemical and thermal energy availability. These changes may impact ecosystem functioning through their influence on functional diversity. We investigate patterns of functional diversity, functional niches, and functional traits in bivalve communities across the energetic gradient of the deep Atlantic Ocean. We use the functional traits feeding type, tiering, and motility level to define the axes of functional space and the unique combinations of these traits as functional niches. We find that increased energy affords new species, added into functional space through niche expansion rather than niche packing. Underlying this pattern are complex dynamics of gains and losses of individual functional niches, with few adapted to the low- and high-energy extremes, and most occurring at intermediate energy. Adaptive qualities of specific traits are evidenced by those functional niches occurring at energetic extremes. Tradeoffs between these traits within the intermediate energy zone underlie an increased coexistence of functional niches, which in turn drives a unimodal pattern of functional niches and expansion of used functional space. This work suggests that energy-limited communities may be especially vulnerable to continued shifts in food availability through the Anthropocene.
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Affiliation(s)
- S. River D. Bryant
- Louisiana Universities Marine Consortium, 8124 Highway 56, Chauvin, LA 70344, USA
- Department of Biology, University of Louisiana at Lafayette, 410 E. St. Mary Blvd., Billeaud Hall, Lafayette, LA 70503, USA
| | - Craig R. McClain
- Louisiana Universities Marine Consortium, 8124 Highway 56, Chauvin, LA 70344, USA
- Department of Biology, University of Louisiana at Lafayette, 410 E. St. Mary Blvd., Billeaud Hall, Lafayette, LA 70503, USA
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4
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Bryant SRD, McClain CR. Energetic constraints on body-size niches in a resource-limited marine environment. Biol Lett 2022; 18:20220112. [PMID: 35975630 PMCID: PMC9382453 DOI: 10.1098/rsbl.2022.0112] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2022] [Accepted: 07/28/2022] [Indexed: 11/12/2022] Open
Abstract
Body size of life on the Earth spans many orders of magnitude, and with it scales the energetic requirements of organisms. Thus, changes in environmental energy should impact community body-size distributions in predictable ways by reshaping ecological and niche dynamics. We examine how carbon, oxygen and temperature, three energetic drivers, impact community size-based assembly in deep-sea bivalves. We demonstrate that body-size distributions are influenced by multiple energetic constraints. Relaxation in these constraints leads to an expansion of body-size niche space through the addition of novel large size classes, increasing the standard deviation and mean of the body-size distribution. With continued Anthropogenic increases in temperature and reductions in carbon availability and oxygen in most ocean basins, our results point to possible radical shifts in invertebrate body size with the potential to impact ecosystem function.
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Affiliation(s)
- S. River D. Bryant
- Department of Biology, University of Louisiana-Lafayette, 410 E St. Mary Boulevard, Billeaud Hall, Lafayette, LA 70503, USA
- Louisiana Universities Marine Consortium, 8124 Highway 56, Chauvin, LA 70344, USA
| | - Craig R. McClain
- Department of Biology, University of Louisiana-Lafayette, 410 E St. Mary Boulevard, Billeaud Hall, Lafayette, LA 70503, USA
- Louisiana Universities Marine Consortium, 8124 Highway 56, Chauvin, LA 70344, USA
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5
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Bivalve Diversity on the Continental Shelf and Deep Sea of the Perdido Fold Belt, Northwest Gulf of Mexico, Mexico. DIVERSITY 2021. [DOI: 10.3390/d13040166] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Mollusk diversity in coastal areas of the Gulf of Mexico (GOM) has been studied extensively, but this is not the case for deep-water habitats. We present the first quantitative characterization of mollusks in shallow and deep waters of the Perdido Fold Belt. The data came from two research cruises completed in 2017. Sediment samples were collected from 56 sites using a 0.25-m2 box corer. We tested hypotheses about spatial patterns of α, β, and γ-diversity of bivalves in two water-depth zones, the continental shelf (43–200 m) and bathyal zone (375–3563 m). A total of 301 bivalves belonging to 39 species were identified. The two zones display similar levels of γ-diversity, but host different bivalve assemblages. In general, α-diversity was higher on the continental shelf, whereas β-diversity was higher in the bathyal zone. These patterns can be explained by the higher input of carbon (energy) to the near-coast shelf zone, as well as by the greater topographic complexity of habitats in the bathyal zone. These results enabled us to propose redirection of sampling efforts for environmental characterization from continental zones to the deep-water zone, especially in the context of environmental assessments during oil and gas exploration and production.
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6
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Affiliation(s)
- Craig R. McClain
- Louisiana Universities Marine Consortium (LUMCON) Chauvin LA USA
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7
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Wei C, Chen M, Wicksten MK, Rowe GT. Macrofauna bivalve diversity from the deep northern Gulf of Mexico. Ecol Res 2020. [DOI: 10.1111/1440-1703.12077] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Affiliation(s)
- Chih‐Lin Wei
- Institute of Oceanography National Taiwan University Taipei Taiwan
| | - Min Chen
- ExxonMobil Research and Engineering Annandale New Jersey
| | - Mary K. Wicksten
- Department of Biology Texas A&M University College Station Texas
| | - Gilbert T. Rowe
- Department of Marine Biology Texas A&M University at Galveston Galveston Texas
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8
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Victorero L, Robert K, Robinson LF, Taylor ML, Huvenne VAI. Species replacement dominates megabenthos beta diversity in a remote seamount setting. Sci Rep 2018. [PMID: 29515196 PMCID: PMC5841424 DOI: 10.1038/s41598-018-22296-8] [Citation(s) in RCA: 51] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022] Open
Abstract
Seamounts are proposed to be hotspots of deep-sea biodiversity, a pattern potentially arising from increased productivity in a heterogeneous landscape leading to either high species co-existence or species turnover (beta diversity). However, studies on individual seamounts remain rare, hindering our understanding of the underlying causes of local changes in beta diversity. Here, we investigated processes behind beta diversity using ROV video, coupled with oceanographic and quantitative terrain parameters, over a depth gradient in Annan Seamount, Equatorial Atlantic. By applying recently developed beta diversity analyses, we identified ecologically unique sites and distinguished between two beta diversity processes: species replacement and changes in species richness. The total beta diversity was high with an index of 0.92 out of 1 and was dominated by species replacement (68%). Species replacement was affected by depth-related variables, including temperature and water mass in addition to the aspect and local elevation of the seabed. In contrast, changes in species richness component were affected only by the water mass. Water mass, along with substrate also affected differences in species abundance. This study identified, for the first time on seamount megabenthos, the different beta diversity components and drivers, which can contribute towards understanding and protecting regional deep-sea biodiversity.
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Affiliation(s)
- Lissette Victorero
- National Oceanography Centre, University of Southampton Waterfront Campus, Southampton, SO14 3ZH, United Kingdom. .,University of Southampton, Ocean and Earth Science, Southampton, SO14 3ZH, United Kingdom.
| | - Katleen Robert
- National Oceanography Centre, University of Southampton Waterfront Campus, Southampton, SO14 3ZH, United Kingdom.,Fisheries and Marine Institute of Memorial University, St. John's, NL A1C 5R3, Canada
| | - Laura F Robinson
- University of Bristol, School of Earth Sciences, Bristol, BS8 1RJ, United Kingdom
| | - Michelle L Taylor
- University of Essex, School of Biological Sciences, Colchester, CO4 3SQ, United Kingdom
| | - Veerle A I Huvenne
- National Oceanography Centre, University of Southampton Waterfront Campus, Southampton, SO14 3ZH, United Kingdom
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9
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Effects of latitude and depth on the beta diversity of New Zealand fish communities. Sci Rep 2017; 7:8081. [PMID: 28808296 PMCID: PMC5556088 DOI: 10.1038/s41598-017-08427-7] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2017] [Accepted: 07/12/2017] [Indexed: 11/09/2022] Open
Abstract
Marine ecosystems are difficult to sample quantitatively at increasing depth. Hence, few studies attempt to measure patterns of beta diversity for ecological communities in the deep sea. Here we (i) present and quantify large-scale gradients in fish community structure along depth and latitude gradients of the New Zealand EEZ, (ii) obtain rigorous quantitative estimates of these depth (50-1200 m) and latitudinal effects (29.15-50.91°S) and their interaction, and (iii) explicitly model how latitudinal beta diversity of fishes varies with depth. The sampling design was highly structured, replicated and stratified for latitude and depth, using data obtained from 345 standardised baited remote underwater stereo-video deployments. Results showed that gradients in fish community structure along depth and latitude were strong and interactive in New Zealand waters; latitudinal variation in fish communities progressively decreased with depth following an exponential decay (r 2 = 0.96), revealing increasingly similar fish communities with increasing depth. In contrast, variation in fish community structure along the depth gradient was of a similar magnitude across all of the latitudes investigated here. We conclude that an exponential decay in beta diversity vs depth exists for fish communities present in areas shallower than the New Zealand upper continental slope.
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10
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Quattrini AM, Gómez CE, Cordes EE. Environmental filtering and neutral processes shape octocoral community assembly in the deep sea. Oecologia 2016; 183:221-236. [DOI: 10.1007/s00442-016-3765-4] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2016] [Accepted: 10/30/2016] [Indexed: 11/28/2022]
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11
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Plante CJ, Fleer V, Jones ML. Neutral processes and species sorting in benthic microalgal community assembly: effects of tidal resuspension. JOURNAL OF PHYCOLOGY 2016; 52:827-839. [PMID: 27373762 DOI: 10.1111/jpy.12445] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2015] [Accepted: 05/04/2016] [Indexed: 06/06/2023]
Abstract
Benthic microalgae (BMA) provide vital food resources for heterotrophs and stabilize sediments with their extracellular secretions. A central goal in ecology is to understand how processes such as species interactions and dispersal, contribute to observed patterns of species abundance and distribution. Our objectives were to assess the effects of sediment resuspension on microalgal community structure. We tested whether taxa-abundance distributions could be predicted using neutral community models (NCMs) and also specific hypotheses about passive migration: (i) As migration decreases in sediment patches, BMA α-diversity will decrease, and (ii) As migration decreases, BMA community dissimilarity (β-diversity) will increase. Co-occurrence indices (checkerboard score and variance ratio) were also computed to test for deterministic factors, such as competition and niche differentiation, in shaping communities. Two intertidal sites (mudflat and sand bar) differing in resuspension regime were sampled throughout the tidal cycle. Fluorometry and denaturing gradient gel electrophoresis were utilized to investigate diatom community structure. Observed taxa-abundances fit those predicted from NCMs reasonably well (R2 of 0.68-0.93), although comparisons of observed local communities to artificial randomly assembled communities rejected the null hypothesis that diatom communities were assembled solely by stochastic processes. No co-occurrence tests indicated a significant role for competitive exclusion or niche partitioning in microalgal community assembly. In general, predictions about relationships between migration and species diversity were supported for local community dynamics. BMA at low tide (lowest migration) exhibited reduced α-diversity as compared to periods of immersion at both mudflat and sand bar sites. β-diversity was higher during low tide emersion on the mudflat, but did not differ temporally at the sand bar site. In between-site metacommunity comparisons, low- and high-resuspension sites exhibited distinct community compositions while the low-energy mudflats contained higher microalgal biomass and greater α-diversity. To our knowledge this is the first study to test the relevance of neutral processes in structuring marine microalgal communities. Our results demonstrate a prominent role for stochastic factors in structuring local BMA community assembly, although unidentified nonrandom processes also appear to play some role. High passive migration, in particular, appears to help maintain species diversity and structure communities in both sand and muddy habitats.
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Affiliation(s)
- Craig J Plante
- Grice Marine Laboratory, Biology Dept., College of Charleston, Charleston, South Carolina, 29412, USA
| | - Virginia Fleer
- Coastal Sciences Dept., USM Gulf Coast Research Laboratory, Ocean Springs, Mississippi, 39564, USA
| | - Martin L Jones
- Mathematics Dept., College of Charleston, Charleston, South Carolina, 29424, USA
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12
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How Should Beta-Diversity Inform Biodiversity Conservation? Trends Ecol Evol 2016; 31:67-80. [DOI: 10.1016/j.tree.2015.11.005] [Citation(s) in RCA: 641] [Impact Index Per Article: 80.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2015] [Revised: 11/09/2015] [Accepted: 11/10/2015] [Indexed: 11/20/2022]
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13
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McClain CR, Rex MA. Toward a Conceptual Understanding of β-Diversity in the Deep-Sea Benthos. ANNUAL REVIEW OF ECOLOGY EVOLUTION AND SYSTEMATICS 2015. [DOI: 10.1146/annurev-ecolsys-120213-091640] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
We review patterns and causes of β-diversity in the deep-sea benthos at different spatial scales and for different body sizes. Changes in species composition occurring with depth are generally gradual, the rate of change being a function of the rate of descent. This gradual change can be interrupted by abrupt environmental shifts, such as oxygen minimum zones, and by major topographic features that alter oceanographic conditions. Changes in species composition with depth can involve both species replacement and species loss, leading to nestedness. Horizontal β-diversity is more moderate than that occurring with depth, except at upper bathyal zones impacted by coastal influences. At very large oceanic scales, both environmental filtering and dispersal limitation influence β-diversity. Although many ecological and evolutionary–historical factors must shape β-diversity in the deep sea, energy availability appears to structure community makeup at all scales examined. We recommend that standardized sampling protocols, statistical methods, and data archiving be used to direct future research.
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Affiliation(s)
- Craig R. McClain
- Department of Biology, Duke University, Durham, North Carolina 27708
| | - Michael A. Rex
- Department of Biology, University of Massachusetts, Boston, Massachusetts 02125
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14
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Piacenza SE, Barner AK, Benkwitt CE, Boersma KS, Cerny-Chipman EB, Ingeman KE, Kindinger TL, Lee JD, Lindsley AJ, Reimer JN, Rowe JC, Shen C, Thompson KA, Thurman LL, Heppell SS. Patterns and Variation in Benthic Biodiversity in a Large Marine Ecosystem. PLoS One 2015; 10:e0135135. [PMID: 26308521 PMCID: PMC4550249 DOI: 10.1371/journal.pone.0135135] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2015] [Accepted: 07/17/2015] [Indexed: 11/18/2022] Open
Abstract
While there is a persistent inverse relationship between latitude and species diversity across many taxa and ecosystems, deviations from this norm offer an opportunity to understand the conditions that contribute to large-scale diversity patterns. Marine systems, in particular, provide such an opportunity, as marine diversity does not always follow a strict latitudinal gradient, perhaps because several hypothesized drivers of the latitudinal diversity gradient are uncorrelated in marine systems. We used a large scale public monitoring dataset collected over an eight year period to examine benthic marine faunal biodiversity patterns for the continental shelf (55-183 m depth) and slope habitats (184-1280 m depth) off the US West Coast (47°20'N-32°40'N). We specifically asked whether marine biodiversity followed a strict latitudinal gradient, and if these latitudinal patterns varied across depth, in different benthic substrates, and over ecological time scales. Further, we subdivided our study area into three smaller regions to test whether coast-wide patterns of biodiversity held at regional scales, where local oceanographic processes tend to influence community structure and function. Overall, we found complex patterns of biodiversity on both the coast-wide and regional scales that differed by taxonomic group. Importantly, marine biodiversity was not always highest at low latitudes. We found that latitude, depth, substrate, and year were all important descriptors of fish and invertebrate diversity. Invertebrate richness and taxonomic diversity were highest at high latitudes and in deeper waters. Fish richness also increased with latitude, but exhibited a hump-shaped relationship with depth, increasing with depth up to the continental shelf break, ~200 m depth, and then decreasing in deeper waters. We found relationships between fish taxonomic and functional diversity and latitude, depth, substrate, and time at the regional scale, but not at the coast-wide scale, suggesting that coast-wide patterns can obscure important correlates at smaller scales. Our study provides insight into complex diversity patterns of the deep water soft substrate benthic ecosystems off the US West Coast.
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Affiliation(s)
- Susan E. Piacenza
- Department of Fisheries and Wildlife, Oregon State University, Corvallis, Oregon, United States of America
| | - Allison K. Barner
- Department of Integrative Biology, Oregon State University, Corvallis, Oregon, United States of America
| | - Cassandra E. Benkwitt
- Department of Integrative Biology, Oregon State University, Corvallis, Oregon, United States of America
| | - Kate S. Boersma
- Department of Integrative Biology, Oregon State University, Corvallis, Oregon, United States of America
| | | | - Kurt E. Ingeman
- Department of Integrative Biology, Oregon State University, Corvallis, Oregon, United States of America
| | - Tye L. Kindinger
- Department of Integrative Biology, Oregon State University, Corvallis, Oregon, United States of America
| | - Jonathan D. Lee
- Department of Geographic Information Science, Oregon State University, Corvallis, Oregon, United States of America
| | - Amy J. Lindsley
- Department of Fisheries and Wildlife, Oregon State University, Corvallis, Oregon, United States of America
| | - Jessica N. Reimer
- Department of Integrative Biology, Oregon State University, Corvallis, Oregon, United States of America
| | - Jennifer C. Rowe
- Department of Fisheries and Wildlife, Oregon State University, Corvallis, Oregon, United States of America
| | - Chenchen Shen
- Department of Integrative Biology, Oregon State University, Corvallis, Oregon, United States of America
| | - Kevin A. Thompson
- Department of Fisheries and Wildlife, Oregon State University, Corvallis, Oregon, United States of America
| | - Lindsey L. Thurman
- Department of Fisheries and Wildlife, Oregon State University, Corvallis, Oregon, United States of America
| | - Selina S. Heppell
- Department of Fisheries and Wildlife, Oregon State University, Corvallis, Oregon, United States of America
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15
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Stegen JC, Lin X, Fredrickson JK, Konopka AE. Estimating and mapping ecological processes influencing microbial community assembly. Front Microbiol 2015; 6:370. [PMID: 25983725 PMCID: PMC4416444 DOI: 10.3389/fmicb.2015.00370] [Citation(s) in RCA: 408] [Impact Index Per Article: 45.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2014] [Accepted: 04/11/2015] [Indexed: 12/01/2022] Open
Abstract
Ecological community assembly is governed by a combination of (i) selection resulting from among-taxa differences in performance; (ii) dispersal resulting from organismal movement; and (iii) ecological drift resulting from stochastic changes in population sizes. The relative importance and nature of these processes can vary across environments. Selection can be homogeneous or variable, and while dispersal is a rate, we conceptualize extreme dispersal rates as two categories; dispersal limitation results from limited exchange of organisms among communities, and homogenizing dispersal results from high levels of organism exchange. To estimate the influence and spatial variation of each process we extend a recently developed statistical framework, use a simulation model to evaluate the accuracy of the extended framework, and use the framework to examine subsurface microbial communities over two geologic formations. For each subsurface community we estimate the degree to which it is influenced by homogeneous selection, variable selection, dispersal limitation, and homogenizing dispersal. Our analyses revealed that the relative influences of these ecological processes vary substantially across communities even within a geologic formation. We further identify environmental and spatial features associated with each ecological process, which allowed mapping of spatial variation in ecological-process-influences. The resulting maps provide a new lens through which ecological systems can be understood; in the subsurface system investigated here they revealed that the influence of variable selection was associated with the rate at which redox conditions change with subsurface depth.
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Affiliation(s)
- James C Stegen
- Fundamental and Computational Sciences Directorate, Biological Sciences Division, Pacific Northwest National Laboratory Richland, WA, USA
| | - Xueju Lin
- Fundamental and Computational Sciences Directorate, Biological Sciences Division, Pacific Northwest National Laboratory Richland, WA, USA
| | - Jim K Fredrickson
- Fundamental and Computational Sciences Directorate, Biological Sciences Division, Pacific Northwest National Laboratory Richland, WA, USA
| | - Allan E Konopka
- Fundamental and Computational Sciences Directorate, Biological Sciences Division, Pacific Northwest National Laboratory Richland, WA, USA
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16
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Melián CJ, Křivan V, Altermatt F, Starý P, Pellissier L, De Laender F. Dispersal dynamics in food webs. Am Nat 2015; 185:157-68. [PMID: 25616136 DOI: 10.1086/679505] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Studies of food webs suggest that limited nonrandom dispersal can play an important role in structuring food webs. It is not clear, however, whether density-dependent dispersal fits empirical patterns of food webs better than density-independent dispersal. Here, we study a spatially distributed food web, using a series of population-dispersal models that contrast density-independent and density-dependent dispersal in landscapes where sampled sites are either homogeneously or heterogeneously distributed. These models are fitted to empirical data, allowing us to infer mechanisms that are consistent with the data. Our results show that models with density-dependent dispersal fit the α, β, and γ tritrophic richness observed in empirical data best. Our results also show that density-dependent dispersal leads to a critical distance threshold beyond which site similarity (i.e., β tritrophic richness) starts to decrease much faster. Such a threshold can also be detected in the empirical data. In contrast, models with density-independent dispersal do not predict such a threshold. Moreover, preferential dispersal from more centrally located sites to peripheral sites does not provide a better fit to empirical data when compared with symmetric dispersal between sites. Our results suggest that nonrandom dispersal in heterogeneous landscapes is an important driver that shapes local and regional richness (i.e., α and γ tritrophic richness, respectively) as well as the distance-decay relationship (i.e., β tritrophic richness) in food webs.
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Affiliation(s)
- Carlos J Melián
- Fish Ecology and Evolution Department, Center for Ecology, Evolution and Biogeochemistry, Swiss Federal Institute of Aquatic Science and Technology, Kastanienbaum, Switzerland; and National Center for Ecological Analysis and Synthesis University of California, Santa Barbara, California
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17
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Girard P, Parrott L, Caron CA, Green DM. Effects of temperature and surface water availability on spatiotemporal dynamics of stream salamanders using pattern-oriented modelling. Ecol Modell 2015. [DOI: 10.1016/j.ecolmodel.2014.09.026] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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18
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McClain CR, Filler R, Auld JR. Does energy availability predict gastropod reproductive strategies? Proc Biol Sci 2014; 281:20140400. [PMID: 25009058 DOI: 10.1098/rspb.2014.0400] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The diversity of reproductive strategies in nature is shaped by a plethora of factors including energy availability. For example, both low temperatures and limited food availability could increase larval exposure to predation by slowing development, selecting against pelagic and/or feeding larvae. The frequency of hermaphroditism could increase under low food availability as population density (and hence mate availability) decreases. We examine the relationship between reproductive/life-history traits and energy availability for 189 marine gastropod families. Only larval type was related to energy availability with the odds of having planktotrophic larvae versus direct development decreasing by 1% with every one-unit increase in the square root of carbon flux. Simultaneous hermaphroditism also potentially increases with carbon flux, but this effect disappears when accounting for evolutionary relationships among taxa. Our findings are in contrast to some theory and empirical work demonstrating that hermaphroditism should increase and planktotrophic development should decrease with decreasing productivity. Instead, they suggest that some reproductive strategies are too energetically expensive at low food availabilities, or arise only when energy is available, and others serve to capitalize on opportunities for aggregation or increased energy availability.
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Affiliation(s)
- Craig R McClain
- National Evolutionary Synthesis Center, 2024 West Main Street, Suite A200, Durham, NC 27705, USA Department of Biology, Duke University, PO Box 90338, Durham, NC 27708, USA
| | - Ryan Filler
- National Evolutionary Synthesis Center, 2024 West Main Street, Suite A200, Durham, NC 27705, USA Department of Biology, Duke University, PO Box 90338, Durham, NC 27708, USA
| | - Josh R Auld
- National Evolutionary Synthesis Center, 2024 West Main Street, Suite A200, Durham, NC 27705, USA Department of Biology, West Chester University, 750 South Church Street, West Chester, PA 19383, USA
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Reed AJ, Morris JP, Linse K, Thatje S. Reproductive morphology of the deep-sea protobranch bivalves Yoldiella ecaudata, Yoldiella sabrina, and Yoldiella valettei (Yoldiidae) from the Southern Ocean. Polar Biol 2014. [DOI: 10.1007/s00300-014-1528-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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20
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McClain C, Barry J. Beta-diversity on deep-sea wood falls reflects gradients in energy availability. Biol Lett 2014; 10:20140129. [PMID: 24718094 DOI: 10.1098/rsbl.2014.0129] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Wood falls on the deep-sea floor represent a significant source of energy into the food-limited deep sea. Unique communities of primarily wood- and sulfide-obligate species form on these wood falls. However, little is known regarding patterns and drivers of variation in the composition of wood fall communities through space and time, and thus, how wood falls contribute to deep-sea biodiversity. Eighteen Acacia logs varying in size were placed and retrieved after five years at a 3200 m site in the Pacific Ocean. We found that the taxonomic composition and structure of deep-sea wood fall communities varied considerably and equated with considerable differences in energy usage and availability. Our findings suggest that natural variability in wood falls may contribute significantly to deep-sea diversity.
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Affiliation(s)
- Craig McClain
- National Evolutionary Synthesis Center, , 2024 West Main St., Durham, NC 27705, USA
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21
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Silva RR, Brandão CRF. Ecosystem-wide morphological structure of leaf-litter ant communities along a tropical latitudinal gradient. PLoS One 2014; 9:e93049. [PMID: 24671213 PMCID: PMC3966852 DOI: 10.1371/journal.pone.0093049] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2013] [Accepted: 03/02/2014] [Indexed: 11/18/2022] Open
Abstract
General principles that shape community structure can be described based on a functional trait approach grounded on predictive models; increased attention has been paid to factors accounting for the functional diversity of species assemblages and its association with species richness along environmental gradients. We analyze here the interaction between leaf-litter ant species richness, the local communities' morphological structure and fundamental niche within the context of a northeast-southeast latitudinal gradient in one of the world's most species-rich ecosystems, the Atlantic Forest, representing 2,700 km of tropical rainforest along almost 20o of latitude in eastern Brazil. Our results are consistent with an ecosystem-wide pattern in communities' structure, with relatively high species turnover but functionally analogous leaf-litter ant communities' organization. Our results suggest directional shifts in the morphological space along the environmental gradient from overdispersed to aggregated (from North to South), suggesting that primary productivity and environmental heterogeneity (altitude, temperature and precipitation in the case) determine the distribution of traits and regulate the assembly rules, shaping local leaf-litter ant communities. Contrary to the expected and most common pattern along latitudinal gradients, the Atlantic Forest leaf litter ant communities show an inverse pattern in richness, that is, richer communities in higher than in lower latitudes. The morphological specialization of communities showed more morphologically distinct communities at low latitudes and species redundancy at high latitudes. We claim that an inverse latitudinal gradient in primary productivity and environmental heterogeneity across the Atlantic forest may affect morphological diversity and species richness, enhancing species coexistence mechanisms, and producing thus the observed patterns. We suggest that a functional framework based on flexible enough traits should be pursued to allow comparisons at local, regional and global levels.
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Affiliation(s)
- Rogério R. Silva
- Museu Paraense Emílio Goeldi, Coordenação de Ciências da Terra e Ecologia, Belém, PA, Brazil
- * E-mail:
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22
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Payne JL, Heim NA, Knope ML, McClain CR. Metabolic dominance of bivalves predates brachiopod diversity decline by more than 150 million years. Proc Biol Sci 2014; 281:20133122. [PMID: 24671970 DOI: 10.1098/rspb.2013.3122] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Brachiopods and bivalves feed in similar ways and have occupied the same environments through geological time, but brachiopods were far more diverse and abundant in the Palaeozoic whereas bivalves dominate the post-Palaeozoic, suggesting a transition in ecological dominance 250 Ma. However, diversity and abundance data alone may not adequately describe key changes in ecosystem function, such as metabolic activity. Here, we use newly compiled body size data for 6066 genera of bivalves and brachiopods to calculate metabolic rates and revisit this question from the perspective of energy use, finding that bivalves already accounted for a larger share of metabolic activity in Palaeozoic oceans. We also find that the metabolic activity of bivalves has increased by more than two orders of magnitude over this interval, whereas brachiopod metabolic activity has declined by more than 50%. Consequently, the increase in bivalve energy metabolism must have occurred via the acquisition of new food resources rather than through the displacement of brachiopods. The canonical view of a mid-Phanerozoic transition from brachiopod to bivalve dominance results from a focus on taxonomic diversity and numerical abundance as measures of ecological importance. From a metabolic perspective, the oceans have always belonged to the clams.
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Affiliation(s)
- Jonathan L Payne
- Department of Geological and Environmental Sciences, Stanford University, , 450 Serra Mall, Building 320, Stanford, CA 94305, USA, National Evolutionary Synthesis Center (NESCent), , 2024 West Main St., Durham, NC 27705, USA
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Putman NF, Naro-Maciel E. Finding the 'lost years' in green turtles: insights from ocean circulation models and genetic analysis. Proc Biol Sci 2013; 280:20131468. [PMID: 23945687 DOI: 10.1098/rspb.2013.1468] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Organismal movement is an essential component of ecological processes and connectivity among ecosystems. However, estimating connectivity and identifying corridors of movement are challenging in oceanic organisms such as young turtles that disperse into the open sea and remain largely unobserved during a period known as 'the lost years'. Using predictions of transport within an ocean circulation model and data from published genetic analysis, we present to our knowledge, the first basin-scale hypothesis of distribution and connectivity among major rookeries and foraging grounds (FGs) of green turtles (Chelonia mydas) during their 'lost years'. Simulations indicate that transatlantic dispersal is likely to be common and that recurrent connectivity between the southwestern Indian Ocean and the South Atlantic is possible. The predicted distribution of pelagic juvenile turtles suggests that many 'lost years hotspots' are presently unstudied and located outside protected areas. These models, therefore, provide new information on possible dispersal pathways that link nesting beaches with FGs. These pathways may be of exceptional conservation concern owing to their importance for sea turtles during a critical developmental period.
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Affiliation(s)
- Nathan F Putman
- Department of Fisheries and Wildlife, Oregon State University, 104 Nash Hall, Corvallis, OR 97330, USA.
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Beta diversity of demersal fish assemblages in the North-Eastern Pacific: interactions of latitude and depth. PLoS One 2013; 8:e57918. [PMID: 23526960 PMCID: PMC3602450 DOI: 10.1371/journal.pone.0057918] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2012] [Accepted: 01/27/2013] [Indexed: 11/29/2022] Open
Abstract
Knowledge of broad-scale global patterns in beta diversity (i.e., variation or turnover in identities of species) for marine systems is in its infancy. We analysed the beta diversity of groundfish communities along the North American Pacific coast, from trawl data spanning 32.57°N to 48.52°N and 51 m to 1200 m depth. Analyses were based on both the Jaccard measure and the probabilistic Raup-Crick measure, which accounts for variation in alpha diversity. Overall, beta diversity decreased with depth, and this effect was strongest at lower latitudes. Superimposed on this trend were peaks in beta diversity at around 400–600 m and also around 1000–1200 m, which may indicate high turnover around the edges of the oxygen minimum zone. Beta diversity was also observed to decrease with latitude, but this effect was only observed in shallower waters (<200 m); latitudinal turnover began to disappear at depths >800 m. At shallower depths (<200 m), peaks in latitudinal turnover were observed at ∼43°N, 39°N, 35°N and 31°N, which corresponded well with several classically observed oceanographic boundaries. Turnover with depth was stronger than latitudinal turnover, and is likely to reflect strong environmental filtering over relatively short distances. Patterns in beta diversity, including latitude-by-depth interactions, should be integrated with other biodiversity measures in ecosystem-based management and conservation of groundfish communities.
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Webb TJ. Marine and terrestrial ecology: unifying concepts, revealing differences. Trends Ecol Evol 2012; 27:535-41. [DOI: 10.1016/j.tree.2012.06.002] [Citation(s) in RCA: 80] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2012] [Revised: 06/12/2012] [Accepted: 06/13/2012] [Indexed: 11/25/2022]
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Abstract
With frigid temperatures and virtually no in situ productivity, the deep oceans, Earth's largest ecosystem, are especially energy-deprived systems. Our knowledge of the effects of this energy limitation on all levels of biological organization is very incomplete. Here, we use the Metabolic Theory of Ecology to examine the relative roles of carbon flux and temperature in influencing metabolic rate, growth rate, lifespan, body size, abundance, biomass, and biodiversity for life on the deep seafloor. We show that the relative impacts of thermal and chemical energy change across organizational scales. Results suggest that individual metabolic rates, growth, and turnover proceed as quickly as temperature-influenced biochemical kinetics allow but that chemical energy limits higher-order community structure and function. Understanding deep-sea energetics is a pressing problem because of accelerating climate change and the general lack of environmental regulatory policy for the deep oceans.
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