DOI: 10.5061/dryad.np5hqc00p
title: Data from: A latitudinal cline in the taxonomic structure of eelgrass epifaunal communities is associated with plant genetic diversity

description: Biogenic structural complexity increases mobile animal diversity and
 abundance at local, regional, and global scales. Yet taxa vary in their
 response to complexity, and when these taxa functionally differ, variation
 in structure created by foundation species may affect ecosystem function.
 We characterized global patterns of epifaunal mesograzers in eelgrass beds
 that varied in structural and genetic composition across 30° latitude.
 Total mesograzer richness decreased with latitude, but this was
 accompanied by a taxonomic shift from peracarid to gastropod dominance.
 Greater eelgrass genetic diversity was strongly correlated with both
 richness and abundance of peracarids, but less so for gastropods. These
 two taxa exhibited complementary functional traits, creating an
 association between genetic diversity and animal functional traits at the
 site level across the eelgrass range. Our results add to a growing body of
 literature that suggests genetic variation in plant traits influences the
 structure and function of faunal assemblages across broad spatial scales.
description: # Data from: A latitudinal cline in the taxonomic structure of eelgrass
 epifaunal communities is associated with plant genetic diversity --- ##
 Description of the data and file structure Environmental, species
 abundance and trait data were collected from 50 sites in the Zostera
 Experimental Network (ZEN) in 2014. This dataset consists of 5 data files:
 1. Bug_traits.csv, created February 21, 2023. Trait data for peracarid
 crustaceans found in epifaunal community samples. \* eat.microalgae,
 eat.macroalgae, eat.seagrass, eat.seagrass.detritus, suspension.feeder,
 detritivore.deposit.feeder, carnivore.parasite.scavenger: Binary feeding
 traits. Does the animal eat the specified food source or feed in the
 specified way? * broadcast.spawner.brooder.lays.egg.case: Parental care
 traits. Is the animal a broadcast spawner, brooder, or does it create an
 egg case? * lecithotrophic.planktotrophic.direct.development:
 Developmental mode. Does the animal have lecithotrophic or planktotrophic
 larvae, or is it a direct developer? * mode.obs.size: Mode body size, as
 measured by sieving epifauna through a series of 9 sieves with pore sizes
 of 0.5, 0.71, 1, 1.4, 2, 2.8, 4, 5.6, 8 mm * max.obs.size: Maximum body
 size, measured as described above * mean.obs.size: Mean body size,
 measured as described above * max.lit.size.mm: Maximum body size in mm as
 described in the literature. * max.lat: Maximum absolute latitude, from
 filtered point occurrences collected from GBIF and OBIS. * min.lat:
 Minimum absolute latitude, from filtered point occurrences collected from
 GBIF and OBIS. * lat.range: Absolute latitudinal range, from filtered
 point occurrences collected from GBIF and OBIS. * lat.mean: Mean absolute
 latitude, from filtered point occurrences collected from GBIF and OBIS *
 marine, brackish, freshwater: Binary salinity traits. Does the animal
 occur in the specified habitat? 2. Snail_traits.csv, created February 21,
 2023. Trait data for gastropod mollusks found in epifaunal community
 samples. Traits are as described above. 3. plot_data.csv, created August
 19, 2016. Count and taxonomic data for each species found in each of 20
 samples (one per plot) from each site. Each species was size-sorted into a
 series of 9 sieves of different mesh sizes. * Site.Code: Two-letter code
 for each broader site containing two paired subsites. * Site: One of two
 paired subsites within each region, with site code. * Subsite: One of two
 paired subsites within each region. * Site.Code.Sampling.Time: Which of
 the two sampling times the site was sampled. * Plot.ID: Which plot (of 20)
 was sampled in each subsite. * Unique.ID: Unique combination of site,
 subsite, plot, and sampling time for each plot. * Old.Species.Name:
 Original name as identified in 2014. * Sieve.8, Sieve.5.6, Sieve.4,
 Sieve.2.8, Sieve.2, Sieve.1.4, Sieve.1, Sieve.0.71, Sieve.0.5: Number of
 individuals collected in each sieve (mesh size in mm) * Unknown.Size:
 Number of individuals of unknown size * Bodies: Number of headless bodies
 * Heads: Number of bodiless heads * Total.Abundance.Whole: Total abundance
 of whole animals across all sieves * Total.Abundance.Partials: Total
 abundance of whole and partial animals across all sieves * Molts: Number
 of molts * Species.Revised: Species name from WoRMS, 2016 * Group.Revised:
 Broader taxonomic group * Subspecies, Species, Subgenus, Genus, Tribe,
 Subfamily, Family, Superfamily, Subsection, Section, Parvorder,
 Infraorder, Suborder, Order, Superorder, Infraclass, Subclass, Class,
 Superclass, Subphylum, Phylum: Taxonomic ranks from WoRMS, 2016 *
 Finest.Taxonomic.Resolution: The name for the finest taxonomic level of
 the animal from WoRMS, 2016 * Finest.Taxonomic.Resolution.Level: The rank
 of the finest taxonomic level of the animal from WoRMS, 2016 4.
 grass_plots.csv, created April 17, 2023. Eelgrass morphological
 measurements were collected from each of the 20 plots in each site. *
 Site.Code: As described above * Site: As described above * Sampling.Time:
 As described above * Unique.ID: As described above * Plot.ID: As described
 above * Shoots.Zmarina.per.m2: Number of shoots in a standard 20-cm
 diameter wire sampling ring, standardized to square meters. *
 Mean.Sheath.Width.cm.: Mean width of eelgrass shoots measured at the end
 of the leaf sheath (where leaves emerge), averaged over 5 random shoots *
 Mean.Sheath.Length.cm.: Mean length of eelgrass leaf sheaths, averaged
 over 5 random shoots * Mean.Longest.Leaf.Length.cm.: Mean length of the
 longest leaf on an eelgrass shoot, averaged over 5 random shoots *
 Mean.Above.Zmarina.g: Total aboveground biomass of eelgrass averaged
 across two 20-cm diameter cores. 5. site_data.csv, created August 20,
 2017. Site-level summary data on eelgrass habitat structure, in-situ
 abiotic environmental data, predation intensity, and abiotic environmental
 data collected from the Bio-Oracle dataset. * Site.Code: As described
 above * Site: As described above * Subsite: As described above *
 Subsite.Name: The name of the subsite * Ocean: Was the site in the
 Atlantic or Pacific? * Coast: Combination of ocean and basin value for
 each site * Basin: Was the site on the eastern or western margin of the
 ocean? * Latitude: Subsite latitude * Longitude: Subsite longitude *
 Sampling.Time: Which of the two sampling times the site was sampled *
 Month: Month corresponding to the sampling time * Date.Collected: Date the
 subsite was sampled * Temperature.C: In-situ temperature (ºC) *
 Salinity.ppt: In-situ salinity (ppt) * GenotypicRichness: Effective number
 of distinct genotypes * AllelicRichness: Average number of alleles per
 locus, normalized to 7 genets * Mean.Shoots.Zmarina.per.m2: Average shoot
 density across 20 plots per subsite. * Mean.Site.Std.Periphyton: Mean
 epiphyte load (g cm-2 eelgrass) * Mean.Site.Std.TotalEpibiota: Mean total
 epibiont load (g cm-2 eelgrass) * Mean.Macroalgae.g.m2: Mean plot-level
 macroalgal biomass * Sheath.Width.cm.: Average eelgrass sheath width
 across 20 plots per subsite * Sheath.Length.cm.: Average eelgrass sheath
 length across 20 plots per subsite * Longest.Leaf.Length.cm.: Average
 length of the longest eelgrass leaf across 20 plots per subsite *
 Above.Zmarina.g TOTAL.Seagrass.Biomass: Total aboveground eelgrass biomass
 * Total.Seagrass.Biomass.Above: Total aboveground seagrass biomass
 (eelgrass and others, if present) * Mean.Leaf.PercN: Mean % Nitrogen of
 measured eelgrass leaves. * Mean.Leaf.PercC: Mean % Carbon of measured
 eelgrass leaves. * Mean.Pred.Amphipod, Mean.Pred.Gastropod,
 Mean.Pred.Lettuce, Mean.Pred.Squid: Predation on tethered animals or kale,
 averaged across 20 prey tethering units per subsite. *
 Mean.Epifaunal.Richness: Average observed epifaunal richness across 20
 plots per subsite * Mean.Total.Abund: Average epifaunal abundance across
 20 plots per subsite * Mean.Std.Total.Abund: Average epifaunal abundance
 across 20 plots per subsite, standardized by macrophyte biomass * Omega:
 Site-level aragonite saturation state. * calcite: Site-level calcite
 concentration (mmol m-3) * chlomax, chlomean, chlomin, chlorange:
 Site-level maximum, mean, minimum, and range of chlorophyll a (mg m-3) *
 cloudmax,cloudmean, cloudmin: Site-level maximum, mean, and minimum %
 cloud cover * damax, damean, damin: Site-level maximum, mean, and minimum
 diffuse attenuation coefficient (m-1) * dissox: Site-level dissolved
 oxygen concentration (mmol m-3) * nitrate: Site-level nitrate
 concentration (mmol m-3) * parmax, parmean: Site-level maximum and mean
 photosynthetically active radiation (E m-2 year-1) * ph: Site-level pH *
 phos: Site-level phosphorus concentration (mmol m-3) * phosphate:
 Site-level phosphate concentration (mmol m-3) * salinity: Annual mean
 site-level salinity (ppt) * silicate: Site-level silicate concentration
 (mmol m-3) * sstmax, sstmean, sstmin, sstrange: Annual maximum, mean,
 minimum, and range of sea surface temperature (ºC) ## Sharing/Access
 information * Data was derived from the following sources: Species
 abundance and environmental parameters were collected according to
 protocols described in Gross et. al 2024 (doi: 10.1111/geb.13918), Duffy
 et al. 2022 (doi: 10.1073/pnas.2121425119), Gross et al. 2022 (doi:
 0.1098/rspb.2021.1762), and Reynolds et al. 2018 (doi: 10.1002/ecy.2064),
 the World Ocean Database and Bio-ORACLE. Trait data was compiled from
 literature, measured individuals, and the Ocean Biogeographic Information
 System and the Global Biodiversity Information Facility records as
 described in the Methods section and supplementary materials of Gross et
 al. 2024. ## Code/Software Most_Analyses.R is a script covering data
 curation and most analyses recorded in the manuscript, including: *
 Modeling latitudinal gradients in richness and species composition in
 epifaunal communities * Modeling the relationships between the richness
 and abundance of peracarids and gastropods and the genetic diversity and
 structural complexity of eelgrass. * Examining the relationship between
 the relative abundance of peracarids vs. gastropods in a site and the
 similarity of site-level community-weighted mean functional traits.
 RF_model_selection.R is a script that runs a random forest analysis on
 predictor traits from site_data.csv to select candidate predictors that
 are then compared by AICc scores and subject to model selection.
 GEB_figures.R is a script that creates all of the figures in the main text
 and supplementary material.