Research ArticleBIODIVERSITY

Community-level regulation of temporal trends in biodiversity

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Science Advances  26 Jul 2017:
Vol. 3, no. 7, e1700315
DOI: 10.1126/sciadv.1700315
  • Fig. 1 Regulated and unregulated time series of species richness and total abundance.

    Histograms of statistically significant (dark hue) and nonsignificant (light hue) ADF test results for species richness (top) and total abundance (bottom) of 59 monitored assemblages. Individual P values for each assemblage were converted to standardized deviates for plotting on a continuous scale. Standardized effect sizes (SES) of less than ~−2.0 are statistically significant at P < 0.05 and indicated a pattern of regulated temporal fluctuations. The vertical black zero line, which indicates a tail probability of 0.50, is highlighted for comparison.

  • Fig. 2 Beta diversity partition of assemblage time series.

    Each pie chart represents a different assemblage, plotted at its jittered location on the globe. Beta diversity was partitioned using the method of Baselga (29). Blue fraction, proportion of beta diversity attributable to changes in species composition; green fraction, proportion of beta diversity attributable to changes in species richness.

  • Fig. 3

    Contrasting dynamics of regulated assemblages versus random walks. In the absence of a perturbation, it is difficult to visually distinguish the dynamics of a regulated assemblage (A) versus an unconstrained random walk (B), although they are discriminated by the ADF test [P = 0.020 (A) and P = 0.545 (B)]. However, if the assemblage is reduced in a single time step from its equilibrium level of 100 species to 10 species, the regulated assemblage recovers (C), whereas the unregulated assemblage does not (D). Trajectories were simulated with an AR1 autoregressive model, ΔN = Nt + 1Nt = − (Ntc)(1 − φ) + εt, where c = 100 and εt ~ N(0, σ = 2). For the regulated trajectories, φ = 0.900, and for the random walk trajectories, φ = 0.999. To simplify the appearance of (D), simulated values that were less than 1 were redrawn as 1. The ADF test is a one-tailed statistical test for whether |φ| < 1.0.

Supplementary Materials

  • Supplementary material for this article is available at http://advances.sciencemag.org/cgi/content/full/3/7/e1700315/DC1

    Supplementary Text

    fig. S1. Time series of uncorrelated white noise.

    fig. S2. Time series of uncorrelated white noise with a linear temporal trend.

    fig. S3. Time series of uncorrelated white noise with a one-time perturbation.

    fig. S4. Time series of random walk.

    fig. S5. Time series of a random walk with a linear temporal trend.

    fig. S6. Time series of a random walk with a one-time perturbation.

    fig. S7. Time series of a regulated autoregressive process.

    fig. S8. Time series of a regulated autoregressive process with a linear temporal trend.

    fig. S9. Time series of a regulated autoregressive process with a one-time perturbation.

    fig. S10. Logic tree for analysis and interpretation of community time series.

    fig. S11. Benchmark analysis of ADF test.

    fig. S12. Benchmark analysis of ADF test.

    fig. S13. Benchmark analysis of ADF test.

    fig. S14. Statistical tests for effects of latitudinal band (=climate), taxonomic group, and realm on standardized effect sizes (z scores) of species richness and total abundance.

    table S1. Number of significant (P < 0.05) and nonsignificant test results for assemblage-level regulation of species richness or abundance.

    table S2. Number of significant (P < 0.05) and nonsignificant test results for assemblage-level regulation of species richness or abundance.

    table S3. Number of significant (P < 0.05) and nonsignificant test results for assemblage-level regulation of species richness or abundance.

    table S4. Results of ADF tests for temperature time series.

    table S5. Correlations of species richness and abundance with air or seawater temperature.

    table S6. Variance ratio tests for patterns of compensatory fluctuations in total abundance.

    table S7. Null model tests for the slope of the relationship between the observed number of colonizations at time t and the observed number of extinctions at time t + x.

    table S8. Primary references and metadata for 59 assemblage time series data sets.

    References (53137)

  • Supplementary Materials

    This PDF file includes:

    • Supplementary Text
    • fig. S1. Time series of uncorrelated white noise.
    • fig. S2. Time series of uncorrelated white noise with a linear temporal trend.
    • fig. S3. Time series of uncorrelated white noise with a one-time perturbation.
    • fig. S4. Time series of random walk.
    • fig. S5. Time series of a random walk with a linear temporal trend.
    • fig. S6. Time series of a random walk with a one-time perturbation.
    • fig. S7. Time series of a regulated autoregressive process.
    • fig. S8. Time series of a regulated autoregressive process with a linear temporal trend.
    • fig. S9. Time series of a regulated autoregressive process with a one-time perturbation.
    • fig. S10. Logic tree for analysis and interpretation of community time series.
    • fig. S11. Benchmark analysis of ADF test.
    • fig. S12. Benchmark analysis of ADF test.
    • fig. S13. Benchmark analysis of ADF test.
    • fig. S14. Statistical tests for effects of latitudinal band (=climate), taxonomic group, and realm on standardized effect sizes (z scores) of species richness and total abundance.
    • table S1. Number of significant (P < 0.05) and nonsignificant test results for assemblage-level regulation of species richness or abundance.
    • table S2. Number of significant (P < 0.05) and nonsignificant test results for assemblage-level regulation of species richness or abundance.
    • table S3. Number of significant (P < 0.05) and nonsignificant test results for assemblage-level regulation of species richness or abundance.
    • table S4. Results of ADF tests for temperature time series.
    • table S5. Correlations of species richness and abundance with air or seawater temperature.
    • table S6. Variance ratio tests for patterns of compensatory fluctuations in total abundance.
    • table S7. Null model tests for the slope of the relationship between the observed number of colonizations at time t and the observed number of extinctions at time t + x.
    • Legend for table S8
    • References (53–137)

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    Other Supplementary Material for this manuscript includes the following:

    • table s8 (.csv format). Primary references and metadata for 59 assemblage time series data sets.

    Files in this Data Supplement: