DOI: 10.5061/dryad.8sf7m0cjh
title: Phylogenetic relatedness mediates persistence and density of soil seed banks

description: Soil seed banks can strongly affect survival and expansion of plant
 populations by spreading mortality risks and distributing genetic
 diversity through time. Knowledge of the main factors regulating the
 ability of seeds to persist in the soil beyond the first growing season is
 however limited. While morphological and physiological seed traits, and
 the degree of environmental uncertainty are considered important in
 shaping the seed-banking strategies of plants, global assessments that
 explicitly account for phylogenetic relatedness are lacking. Using a
 global seed bank database comprising data for 2350 angiosperms, we
 examined the extent to which two seed bank properties, i.e., seed bank
 type (transient vs. persistent) and density of viable seed banks, are
 determined by phylogenetic relatedness. We then tested phylogenetic
 correlations between these properties with seed mass and seed dormancy
 (dormant vs. non-dormant), and the contribution of phylogenetic
 relatedness relative to that of climatic and habitat-related variables in
 shaping seed bank properties. We found significant phylogenetic signal in
 seed bank type and density, providing evidence that the ability to form
 persistent seed banks is not randomly distributed across the phylogeny.
 While the ability to persist in the soil was phylogenetically correlated
 to the production of dormant and smaller seeds, seed mass and seed
 dormancy per se were poor predictors of seed persistence. Interestingly,
 habitat-related variables (mainly disturbance and canopy openness) but not
 climate significantly affected the ability of seed plants to form
 persistent seed banks. Synthesis: Our study is the first to show that
 phylogenetic relatedness plays an important role in explaining seed bank
 properties in angiosperms and how these properties relate to early
 life-history traits, climate and habitat-related variables. These findings
 represent a starting point to assess the generality of persistent seed
 banks as a bet-hedging strategy in unpredictable environments and provides
 important insights into how seed plants might respond to global
 environmental changes. 
description: This dataset contains soil seed bank
 data, i.e., seed bank type (transient vs.
 persistent, <em>sensu</em> Thompson et al., 1997), and seed
 bank density (mean number of seedlings per square meter), for 2350
 angiosperm taxa obtained from 195 studies, in 11,893 records. Relevant
 literature was identified by searching the Web of Science (ISI) and Google
 Scholar, using the keyword ‘seed’ or ‘diaspore’ in combination with
 ‘bank’, ‘below-ground’, ‘buried’, ‘community’, ‘flora’, ‘reservoir’,
 ‘soil’, and ‘stored’. Additional studies were searched by screening the
 reference lists provided in the resulting papers as well as papers citing
 the papers originally retrieved. For papers that contained potentially
 relevant data that could not be extracted directly, we contacted the
 authors for additional information. A full description of the methodology
 used to compile an earlier version of this dataset (updated until April
 2018) is described in Gioria et al<i>.</i> (2019), including
 the criteria used to identify and select the sources from which seed bank
 data were extracted. The last search for relevant literature in the
 present study was conducted in February 2020. This dataset includes seed bank data
 collected from the native distribution range and estimated using the
 seedling emergence approach (Thompson et al., 1997), thus estimating only
 viable soil seed banks. We included only studies providing mean density
 values at the study sites, coming from multiple samples (and not values
 from single samples at each site), maximum densities per site, total
 numbers of seeds/seedlings per site, or frequency values. This was done to
 minimise any potential confounding effect associated with the large
 spatial and temporal variation that characterises soil seed
 banks. For each species, we
 included information on seed mass (mg), obtained from the Royal Botanic
 Gardens Kew Seed Information Database (2020), seed dormancy (dormant vs.
 non-dormant), based on the classification provided in the Baskin Dormancy
 Database (Baskin & Baskin, 2014), and life form (annual,
 perennial, woody). For each
 record, we provided the geographic coordinates and information on 11
 climatic variables (2.5 minutes) extracted from WorldClim (Hijmans et al.,
 2005). We also provided
 information on three habitat variables summarising local environmental
 conditions, i.e., disturbance (disturbed vs. nonditurbed), soil moisture
 (dry, moist, wet), and openness (open vs. close
 canopies).    References
 Baskin, C. C. & Baskin, J. M.
 (2014). <i>Seeds: ecology, biogeography, and evolution of dormancy
 and germination</i> (2nd ed.). San Diego, CA:
 Academic/Elsevier. Gioria,
 M., Le Roux, J. J., Hirsch, H., Moravcová, L. & Pyšek, P. (2019).
 Characteristics of the soil seed bank of invasive and non-invasive plants
 in their native and alien distribution range. <i>Biological
 Invasions</i>, 21, 2313–2332. Hijmans, R. J., Cameron, S. E., Parra, J. L.,
 Jones, P. G. & Jarvis, A. (2005). Very high- resolution
 interpolated climate surfaces for global land areas.
 <i>International Journal of Climatology</i>, 25,
 1965–1978. Royal Botanic
 Gardens Kew. (2020). Seed Information Database (SID). Version 7.1.
 http://data.kew.org/sid/  Thompson, K., Bakker, J. P. & Bekker,
 R. M. (1997). <i>Soil seed banks of NW Europe: methodology, density
 and longevity</i>. Cambridge, UK: Cambridge University
 Press.
description: There are no missing values in the dataset.