DOI: 10.5061/dryad.g7046
title: Data from: Glaciation as an historical filter of below-ground biodiversity

description: Aim: The latitudinal gradient in species richness is one of the most
 studied biodiversity patterns. Here we explore a north–south gradient in
 earthworm diversity, and evaluate the importance of current and historical
 filters in shaping the distribution of present-day below-ground species
 richness. Location: France. Methods: Using high-resolution data on
 earthworm distributions across France, we document the latitudinal
 gradients in alpha (α), beta (β) and gamma (γ) diversity. We relate these
 gradients to species' traits, taxonomic aggregation and co-occurrence
 patterns, and correlate them with the present climate and the history of
 glaciation in Europe. Results: We found that γ-diversity decreases from
 south to north whereas α-diversity increases along the same latitudinal
 gradient. Communities in formerly glaciated regions are composed of
 smaller, more mobile species and show trait and taxonomical aggregation.
 In more southerly populations, which did not experience glaciation,
 earthworm species are larger, have smaller geographical ranges, and
 communities demonstrate a decrease in species co-occurrence resulting in
 lower local species richness. Main conclusions: We show that species
 richness gradients can present different – sometimes opposite –
 latitudinal trends depending upon the scale of the analysis. This scale
 dependence sheds new light on the underlying causes of global biodiversity
 gradients. The opposing latitudinal trends of the different components of
 diversity suggest that recolonization following glaciations during the
 Pleistocene acted as an environmental filter, and that competitive
 exclusion may be a more dominant ecological force in these former refugial
 areas. Overall our results show that past climate changes have left a deep
 footprint on present-day earthworm diversity patterns, from community to
 macroecological scales, and that different mechanisms of earthworm
 community assembly may predominate at different latitudes.
description: There are two
 tables: 
 <strong>1°
 sites&Species.txt</strong><br> This dataset gathers
 Presence-absence data of all earthworm species(~100sp.) in France and
 Corsica across 1366 localities in France, sampled around 1960. The
 coordinates of the sites and land cover are also provided (in Lambert2
 étendu).<br> Format: sites in rows, species in columns.<br>
 The name of the species is given in the traits table
 <strong>T2° traits.txt</strong><br> This table
 gathers traits data of earthworms that are used for taxonomical
 identification. Each species has a unique ID that can be used to merge
 this dataset with the sites&species table.
 These data are associated with the paper:
 Mathieu, J. and Jonathan Davies, T. (2014), Glaciation as an
 historical filter of below‐ground biodiversity. J. Biogeogr., 41:
 1204-1214. https://doi.org/10.1111/jbi.12284 The data
 themselves come from the book "Lombriciens de France: ecologie et
 systématique" written by Marcel Bouché, M.B. (1972), INRA,
 Paris. The data are occurrences (presence/absence) of ~
 100 earthworm species in France and Corsica, sampled around 1960. There is
 also a table describing anatomical traits of each species.
description: This data come from the book "Lombriciens de France:
 ecologie et systématique" written by Marcel Bouché, M.B. (1972),
 INRA, Paris