Disentangling the relative contributions of factors determining seed physical defence: a global-scale data synthesis

Physical defence investment in seeds varies greatly among plant species and is associated with many potential factors. Exploring the factors explaining the interspecific variation in physical defence has long attracted particular attention in both ecology and evolution studies. However, the relative importance of the factors has not yet been quantitatively evaluated, which may lead to the misunderstanding of the main driver generating such interspecific variation.
Here, by compiling a global database of the seed coat ratio (SCR), a proxy of seed physical defence, for 1,362 species, we provided the first quantification of the relative explanations of six factors that have been commonly considered to be associated with the interspecific variation in SCR: seed mass, seed desiccation response (desiccation-sensitive vs. desiccation-tolerant), seed dormancy (nondormant, physical dormant or other dormant types), growth form (herbaceous vs. woody), fruit type (dry vs. fleshy), and climate (19 b..., Data on the SCR and seed mass were collected from the literature published up until June 5, 2022. We used ((diaspore$ or “seed* coat$” or (seed$ and (kernel$ or reserve$)) or (seed$ and “embryo* endosperm$”)) and (ratio$ or proportion$ or fraction$ or tissue$ or percent* or weigh* or mass*)) or (seed$ and (defen* or protect*) and (physical* or mechanical*)) as search terms in the ISI Web of Science and further restricted our search to be consistent with the ‘Study Field Categories’ of Wu et al. (2019), with the additional category ‘anatomy morphology’. Google Scholar was also searched with the same keywords to expand our dataset. Finally, 9,322 journal papers written in English were search out. We first screened all the papers based on the titles and abstracts and excluded 6,857 studies that were not relevant to our focused question. For the remaining 2,465 papers, we screened the full texts and finally yielded 85 papers containing available SCR data collected from 203 sampling sites. T...,

seed desiccation response
 1 means desiccation-tolerant, 0 means desiccation-sensitive, blanks mean lack of information.

growth form
 1 means woody, and 0 means herbaceous.

fruit type
 1 means fleshy, 0 means dry, blanks mean lack of information.

nondormant
 1 means nondormant, 0 means dormant, blanks mean lack of information.

physical dormant
 1 means physical dormant, 0 means non physical dormant, blanks mean lack of information.

other dormant
 1 means other dormant (include physiological dormancy, morphological dormancy and morphophysiological dormancy), 0 means nondormant or physical dormant, blanks mean lack of information.

, # Title of Dataset:

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Data from: Disentangling the relative contributions of factors determining seed physical defence: a global-scale data synthesis

## Description of the Data and file structure

Dataset of SCR.xlsx
Excel spreadsheet which includes species information, seed coat ratio, and factors that have been commonly considered as possible drivers of variation in the SCR: seed mass, seed desiccation response, growth form, fruit type, climate, and seed dormancy (nondormant, physical dormant or other dormant types).