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  • 1
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    Online Resource
    On the mismatch in the strength of competition among fossil and modern species of planktonic Foraminifera
    Wiley ; 2019
    In:  Global Ecology and Biogeography Vol. 28, No. 12 ( 2019-12), p. 1866-1878
    Details
    In: Global Ecology and Biogeography, Wiley, Vol. 28, No. 12 ( 2019-12), p. 1866-1878
    Abstract: Many clades display the macroevolutionary pattern of a negative relationship between standing diversity and diversification rates. Competition among species has been proposed as the main mechanism that explains this pattern. However, we currently lack empirical insight into how the effects of individual‐level ecological interactions scale up to affect species diversification. Here, we investigate a clade that shows evidence for negative diversity‐dependent diversification in the fossil record and test whether the clade's modern communities show a corresponding signal of interspecific competition. Location World's oceans. Time period Holocene. Major taxa studied Planktonic Foraminifera (Rhizaria). Methods We explore spatial and temporal ecological patterns expected under interspecific competition. Firstly, we use a community phylogenetics approach to test for signs of local competitive exclusion among ecologically similar species (defined as closely related or of similar shell sizes) by combining species relative abundances in seafloor sediments. Secondly, we analyse whether population abundances of co‐occurring species covary negatively through time using sediment trap time‐series spanning 1–12 years. Results The great majority of the assemblages are indistinguishable from randomly assembled communities, showing no significant spatial co‐occurrence patterns regarding phylogeny or size similarity. Through time, most species pairs correlated positively, indicating synchronous rather than compensatory population dynamics. Main conclusions We found no detectable evidence for interspecific competition structuring extant planktonic Foraminifera communities. Species co‐occurrences and population dynamics are likely regulated by the abiotic environment and/or distantly related species, rather than intra‐clade density‐dependent processes. This interpretation contradicts the idea that competition drives the clade's macroevolutionary dynamics. One way to better integrate community ecology and macroevolution is to consider that diversification dynamics are influenced by groups that interact ecologically even when distantly related.
    Type of Medium: Online Resource
    ISSN: 1466-822X , 1466-8238
    URL: Issue
    URL: Article
    DOI: 10.1111/geb.v28.12
    DOI: 10.1111/geb.13000
    Language: English
    Publisher: Wiley
    Publication Date: 2019
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    detail.hit.zdb_id: 2021283-5
    SSG: 12
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  • 2
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    Scale dependence of temporal biodiversity change in modern and fossil marine plankton
    Wiley ; 2020
    In:  Global Ecology and Biogeography Vol. 29, No. 6 ( 2020-06), p. 1008-1019
    Details
    In: Global Ecology and Biogeography, Wiley, Vol. 29, No. 6 ( 2020-06), p. 1008-1019
    Abstract: Biodiversity dynamics comprise evolutionary and ecological changes on multiple temporal scales from millions of years to decades, but they are often interpreted within a single time frame. Planktonic foraminifera communities offer a unique opportunity for analysing the dynamics of marine biodiversity over different temporal scales. Our study aims to provide a baseline for assessments of biodiversity patterns over multiple time‐scales, which is urgently needed to interpret biodiversity responses to increasing anthropogenic pressure. Location Global (26 sites). Time period Five time‐scales: multi‐million‐year (0–7 Myr), million‐year (0–0.5 Myr), multi‐millennial (0–15 thousand years), millennial (0–1,100 years) and decadal (0–32 years). Major taxa studied Planktonic foraminifera. Methods We analysed community composition of planktonic foraminifera at five time‐scales, combining measures of standing diversity (richness and effective number of species, ENS) with measures of temporal community turnover (presence–absence‐based, dominance‐based). Observed biodiversity patterns were compared with the outcome of a neutral model to separate the effects of sampling resolution (the highest in the shortest time series) from biological responses. Results Richness and ENS decreased from multi‐million‐year to millennial time‐scales, but higher standing diversity was observed on the decadal scale. As predicted by the neutral model, turnover in species identity and dominance was strongest at the multi‐million‐year time‐scale and decreased towards the millennial scale. However, contrary to the model predictions, modern time series show rapid decadal variation in the dominance structure of foraminifera communities, which is of comparable magnitude as over much longer time periods. Community turnover was significantly correlated with global temperature change, but not on the shortest time‐scale. Main conclusions Biodiversity patterns can be to some degree predicted from the scaling effects related to different durations of time series, but changes in the dominance structure observed over the last few decades reach higher magnitude, probably forced by anthropogenic effects, than those observed over much longer durations.
    Type of Medium: Online Resource
    ISSN: 1466-822X , 1466-8238
    URL: Issue
    URL: Article
    DOI: 10.1111/geb.v29.6
    DOI: 10.1111/geb.13078
    Language: English
    Publisher: Wiley
    Publication Date: 2020
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    detail.hit.zdb_id: 2021283-5
    SSG: 12
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  • 3
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    Online Resource
    Experimental insights into laser diffraction particle sizing of fine‐grained sediments for use in palaeoceanography
    Wiley ; 2009
    In:  Sedimentology Vol. 56, No. 7 ( 2009-12), p. 2192-2206
    Details
    In: Sedimentology, Wiley, Vol. 56, No. 7 ( 2009-12), p. 2192-2206
    Abstract: Grain‐size measurements of fine‐grained sediments based on laser diffraction may contain spurious information due to the over‐estimation of the size and proportion of platy particles. Consequently, some regard the use of laser diffraction particle sizing in palaeoceanography inappropriate. Here, it is shown experimentally that such concerns are not warranted. Laser diffraction particle sizing is known to be fast, precise and allows for detailed particle sizing over a broad size range; it is therefore potentially a very powerful technique if the complications associated with it can be overcome. As most sediments are mixtures of different components transported by different mechanisms, inferences of past environmental parameters require decomposition of the grain‐size record in question. Useful decomposition can only be performed if changes in the contribution of the components are registered predictably by the measuring device. This study reports on mixing experiments which show that the Fritsch A22 laser diffraction particle sizer does indeed register small changes in the contribution of the mixing components in a predictable way. Mixing proportions estimated from the measurements do, however, differ from the initial mixing proportions, but these can be converted with only small errors. Application of the conversion equations to a North Atlantic grain‐size record that showed consistent slowdown of deep‐ocean circulation in response to millennial scale ice‐rafting events during the last glacial does not quantitatively affect the original inferences. Laser diffraction particle sizing of fine‐grained sediments therefore yields reproducible and useful data for palaeoceanographic reconstructions.
    Type of Medium: Online Resource
    ISSN: 0037-0746 , 1365-3091
    URL: Issue
    URL: Article
    DOI: 10.1111/sed.2009.56.issue-7
    DOI: 10.1111/j.1365-3091.2009.01076.x
    RVK:
    RB 10121
    Language: English
    Publisher: Wiley
    Publication Date: 2009
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    detail.hit.zdb_id: 206889-8
    SSG: 13
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  • 4
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    Online Resource
    BioDeepTime: A database of biodiversity time series for modern and fossil assemblages
    Wiley ; 2023
    In:  Global Ecology and Biogeography Vol. 32, No. 10 ( 2023-10), p. 1680-1689
    Details
    In: Global Ecology and Biogeography, Wiley, Vol. 32, No. 10 ( 2023-10), p. 1680-1689
    Abstract: We have little understanding of how communities respond to varying magnitudes and rates of environmental perturbations across temporal scales. BioDeepTime harmonizes assemblage time series of presence and abundance data to help facilitate investigations of community dynamics across timescales and the response of communities to natural and anthropogenic stressors. BioDeepTime includes time series of terrestrial and aquatic assemblages of varying spatial and temporal grain and extent from the present‐day to millions of years ago. Main Types of Variables Included BioDeepTime currently contains 7,437,847 taxon records from 10,062 assemblage time series, each with a minimum of 10 time steps. Age constraints, sampling method, environment and taxonomic scope are provided for each time series. Spatial Location and Grain The database includes 8752 unique sampling locations from freshwater, marine and terrestrial ecosystems. Spatial grain represented by individual samples varies from quadrats on the order of several cm 2 to grid cells of ~100 km 2 . Time Period and Grain BioDeepTime in aggregate currently spans the last 451 million years, with the 10,062 modern and fossil assemblage time series ranging in extent from years to millions of years. The median extent of modern time series is 18.7 years and for fossil series is 54,872 years. Temporal grain, the time encompassed by individual samples, ranges from days to tens of thousands of years. Major Taxa and Level of Measurement The database contains information on 28,777 unique taxa with 4,769,789 records at the species level and another 271,218 records known to the genus level, including time series of benthic and planktonic foraminifera, coccolithophores, diatoms, ostracods, plants (pollen), radiolarians and other invertebrates and vertebrates. There are to date 7012 modern and 3050 fossil time series in BioDeepTime. Software Format SQLite, Comma‐separated values.
    Type of Medium: Online Resource
    ISSN: 1466-822X , 1466-8238
    URL: Issue
    URL: Article
    DOI: 10.1111/geb.v32.10
    DOI: 10.1111/geb.13735
    Language: English
    Publisher: Wiley
    Publication Date: 2023
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    detail.hit.zdb_id: 2021283-5
    SSG: 12
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