DOI: 10.5061/dryad.vmcvdnd1r
title: Impact of the 2011 Tohoku earthquake on the species diversity of rocky intertidal sessile assemblages

description: The impacts of large-scale disturbance events on the species diversity of
 rocky intertidal sessile assemblages across multiple spatial scales are
 not well understood. To evaluate the influence of the 2011 Tohoku
 Earthquake on alpha and beta diversities of rocky intertidal sessile
 assemblages, we censused sessile assemblages in the mid-shore zone from
 2011 to 2019. The census was conducted across 22 study sites on five rocky
 shores along 30 km of the Sanriku Coast of Japan, which is located 150–160
 km north–northwest of the earthquake epicenter. Alpha diversity was
 measured with three Hill numbers (H0, H1, and H2), which represent the
 number of equally common species that would exist in a community with the
 same diversity as the sampled community, with higher values of the
 subscript indicating more weight placed on abundant species. Beta
 diversity was measured with two metrics (BDtotal at two spatial scales).
 Values were compared between the years 2011–2019 and the pre-earthquake
 period (2003–2010). The results show that the Tohoku Earthquake
 significantly altered the species diversity of intertidal sessile
 assemblages across multiple spatial scales. All diversity metrics obtained
 at multiple spatial scales (i.e., alpha diversities: H0, H1, and H2; beta
 diversities: BDtotal at the shore and regional scales) decreased
 immediately after the earthquake and then increased in subsequent years.
 Two years after the earthquake, H0 recovered to within the range of
 pre-earthquake values and H1 and H2 became significantly higher than
 pre-earthquake values. Most metrics of alpha and beta diversities
 recovered to pre-earthquake levels after several years, but regional
 BDtotal remained low for a longer period.
description: # Impact of the 2011 Tohoku Earthquake on the species diversity of rocky
 intertidal sessile assemblages
 [https://doi.org/10.5061/dryad.vmcvdnd1r](https://doi.org/10.5061/dryad.vmcvdnd1r) The alpha diversity and beta diversity data are available in "alpha.csv" and "beta.csv", and code used for analysis is available in "data analysis.R". ## Description of the data and file structure `diversity.csv` * "year": the census year * "h0" is Hill number H0 * "h0se" is the standard error of Hill number H0 * "h1" is Hill number H1 * "h1se" is the standard error of Hill number H1 * "h2" is Hill number H2 * "h2se" is the standard error of Hill number H2 * "bd1" is the BD (beta diversity) total at shore scale * "bd1se" is the standard error of the BD total at shore scale * "bd2" is the BD total at regional scale. `effect size.csv` * "year" is the census year * "h0es" is the effect size of Hill number H0 * "h0esse" is the standard error of the effect size of Hill number H0 * "h1es" is the effect size of Hill number H1 * "h1esse" is the standard error of  the effect size of Hill number H1 * "h2es" is the effect size of Hill number H2 * "h2esse" is the standard error of the effect size of Hill number H2 * "bd1es" is the effect size of the BD total at shore scale * "bd1esse" is the standard error of the effect size of the BD total at shore scale * "bd2es" is the effect size of the BD total at regional scale * "h0up" is the upper limit of 95% CI of the effect size of Hill number H0 * "h0low" is the lower limit of 95% CI of the effect size of Hill number H0 * "h1up" is the upper limit of 95% CI of the effect size of Hill number H1 * "h1low" is the lower limit of 95% CI of the effect size of Hill number H1 * "h2up" is the upper limit of 95% CI of the effect size of Hill number H2 * "h2low" is the lower limit of 95% CI of the effect size of Hill number H2 * "bd1up" is the upper limit of 95% CI of the effect size of BD total at shore scale * "bd1low" is the lower limit of 95% CI of the effect size of BD total at shore scale Please do not revise the format of ".csv" file, the code directly draws the figures in the study using the uploaded ".csv" files. ## Sharing/Access information n/a ## Code/Software All analysis are conduct under R v4.3.1