DOI: 10.5061/dryad.31zcrjds9
title: Traits mediate environmental responses of benthic ciliates in dynamic coastal habitats

description: Aim: Understanding how species’ traits mediate environmental responses
 provides a mechanistic perspective on community assembly processes.
 Although traits that influence the response of multicellular organisms to
 environments have been studied, the identification of such traits in
 unicellular organisms, like ciliates, is underexplored. Since ciliates are
 dominate animals at coastal sandy sediments and contribute significantly
 to interstitial community respiration, identifying links between their
 occurrence and sandy-coast characteristics is crucial for conserving
 biodiversity and protecting coastal habitats. Location: Coasts of China.
 Methods: We used Hierarchical Modeling of Species Communities, a
 trait-based joint species distribution model, to analyze ciliate community
 data collected from 344 sites belonging to 31 beaches across the Chinese
 coastline. Results: We found that physical variables play the most
 important role in determining ciliate occurrence. The beach index which
 combines the tidal range, sediment grain size and beach slope of beach
 selected species based on body size as well as feeding type, while
 sediment grain size constrained different mobility types, with swimming
 species favoring fine sandy sediments. The significant contribution of
 phylogeny in explaining the residual variation among species responses
 indicates that there are phylogenetically conserved but unmeasured traits
 too that influence species’ responses. Species richness of benthic
 ciliates was higher in dissipative beaches with high primary productivity.
 Main conclusions: Based on our research, ciliate occurrence in coastal
 beaches is mediated by their traits which are filtered by local
 environmental variables. The beach index is essential in predicting
 distribution patterns and species richness of benthic ciliates.
 Nevertheless, further research is needed to identify additional traits
 that will enhance the accuracy of predicting ciliate niches. Our study
 provides insights into the mechanisms driving ciliate community assembly
 processes and has implications for the conservation of biodiversity in
 sandy coastal habitats.
description: # Traits mediate environmental responses of benthic ciliates in dynamic
 coastal habitats Abundance and presence/absence data of benthic ciliates,
 trait data, abiotic data and spatial information of 31 sandy beaches along
 the coast of China ## Description of the data and file structure
 ciliate_abun.csv --- abundance data of benthic ciliates (95 species
 collected from 344 sampling sites belonging to 31 beaches) ciliate_PA.csv
 --- presence/absence data of benthic ciliates (95 species collected from
 344 sampling sites belonging to 31 beaches) env_sel.csv--- abiotic
 variables used in HMSC models: 1.  "site": sampling site. For
 example, ALW refers to the name of the beach and the number represents the
 replicate.    2. "BI": beach index. 3. "MPS": mean
 particle size of the sediment.   4. "Salinity_Oct_Nov": mean
 salinity during the period of our sample collection (i.e., October to
 November 2020). 5. "MAT": mean annual temperature. 6.
 "nu.pc1 & 2": the first two axes of the PCA on the five
 nutrients, i.e., ammonia, nitrate, nitrite, phosphate and silicate. 7.
 "log_chla": ln-transformed Chlorophyll *a.* spa.csv---longitude
 and latitude of each sampling site taxon-sel.csv---Phylogenetic
 information of the 95 species trait_com.csv---Five traits used in HMSC
 models.