DOI: 10.5061/dryad.hx3ffbgcj
title: Spider diversity across an elevation gradient in Área de Conservación Guanacaste (ACG), Costa Rica

description: Throughout the Neotropics, temperature and precipitation change with
 elevation and these changes affect the assemblage of species at any
 particular elevation. We documented the diversity of litter-inhabiting
 spiders, (Arachnida: Araneae) along a Costa Rican elevational gradient as
 it relates to covarying abiotic factors such as temperature and
 precipitation. The spiders we collected were principally unidentifiable
 juveniles and so we used Barcode Index Numbers (BINs) derived from DNA
 barcodes as proxies for species-level interim names. We contrasted these
 taxon-based estimates with phylogenetic measures of alpha and beta
 diversity derived from both the mitochondrial DNA barcode region and a
 multi-gene phylogeny of spiders and found that neither the abundance nor
 the species-richness of spiders was significantly correlated with
 elevation, temperature or precipitation. However, we did find that spider
 assemblages in the upper elevation cloud forests were phylogenetically
 clustered, (and this pattern was unrelated to whether the phylogenetic
 patterns were derived mitochondrially or from a multi-gene analysis). One
 standard explanation for such a pattern is that harsh abiotic conditions
 in higher elevation forests have selected for particular spider lineages
 however this remains to be tested fully. The diversity of leaf-litter
 spider species we uncovered was high and further sampling of spider
 abundance and diversity across the ACG is likely to yield many new
 species.
description: DS-ASSPIDER Collection Data.xlsx - This is the collection and
 sequence information associated with each of the samples analysed. All
 specimen information, DNA sequences, and corresponding metadata are
 available on BOLD and will continue to be updated
 (dx.doi.org/10.5883/DS-ASSPIDER).
 ML_pGH16_by_gene_boot1K_named.nwk - A recent comprehensive spider
 phylogeny was published comprising more than 700 genera based on six genes
 (3 nuclear and 3 mitochondrial, including COI) (Wheeler et al. 2017). We
 used Wheeler et al.’s COI dataset to compare our sequences to make interim
 generic assignments based on sequence similarity. Using these generic
 assignments we then calculated genera richness, phylogenetic diversity and
 community structure as inferred from comparison with the larger multi-gene
 Wheeler et al. (2017) phylogeny. This is the Wheeler phylogeny used in
 newick format.  phylo_barcode_180327.nwk - We
 constructed a maximum likelihood tree in MEGA6 using one high-quality
 sequence (greatest length and fewest ambiguities) for each species. This
 tree was created using a general time reversible model with discrete gamma
 distribution. Calculations of the best substitution pattern were made in
 MEGA6 using the “find best DNA model” function. This is that
 barcode-derived phlogeny in newick format. 
 comm_barcode_180327.csv - This is the community matrix of DNA
 barcode derived OTU's and their occurence along this ACG elevational
 gradient.   ML_pGH16_by_gene_boot1K_named_matrix.csv -
 This is the community matrix of genus identified spiders and their
 occurence along the ACG elevational gradient.  Wheeler,
 W. C., J. A. Coddington, L. M. Crowley, D. Dimitrov, P. A. Goloboff, C. E.
 Griswold, G. Hormiga, L. Prendini, M. J. Ramírez, P. Sierwald, L.
 Almeida-silva, F. Alvarez-padilla, M. A. Arnedo, L. R. Benavides Silva, S.
 P. Benjamin, J. E. Bond, C. J. Grismado, E. Hasan, M. Hedin, M. A.
 Izquierdo, F. M. Labarque, J. Ledford, L. Lopardo, W. P. Maddison, J. A.
 Miller, L. N. Piacentini, N. I. Platnick, D. Polotow, D. Silva-dávila, N.
 Scharff, T. Szűts, D. Ubick, C. J. Vink, H. M. Wood, And J. Zhang. 2017.
 The spider tree of life: phylogeny of Araneae based on target-gene
 analyses from an extensive taxon sampling. Cladistics 33:
 574–616.