Data from: Seed dispersal by ungulates as an ecological filter: a trait-based meta-analysis

Plant communities are often dispersal-limited and zoochory can be an
efficient mechanism for plants to colonize new patches of potentially
suitable habitat. We predicted that seed dispersal by ungulates acts as an
ecological filter – which differentially affects individuals according to
their characteristics and shapes species assemblages – and that the filter
varies according to the dispersal mechanism (endozoochory, fur-epizoochory
and hoof-epizoochory). We conducted two-step individual participant data
meta-analyses of 52 studies on plant dispersal by ungulates in fragmented
landscapes, comparing eight plant traits and two habitat indicators
between dispersed and non-dispersed plants. We found that ungulates
dispersed at least 44% of the available plant species. Moreover, some
plant traits and habitat indicators increased the likelihood for plant of
being dispersed. Persistent or nitrophilous plant species from open
habitats or bearing dry or elongated diaspores were more likely to be
dispersed by ungulates, whatever the dispersal mechanism. In addition,
endozoochory was more likely for diaspores bearing elongated appendages
whereas epizoochory was more likely for diaspores released relatively high
in vegetation. Hoof-epizoochory was more likely for light diaspores
without hooked appendages. Fur-epizoochory was more likely for diaspores
with appendages, particularly elongated or hooked ones. We thus observed a
gradient of filtering effect among the three dispersal mechanisms.
Endozoochory had an effect of rather weak intensity (impacting six plant
characteristics with variations between ungulate-dispersed and
non-dispersed plant species mostly below 25%), whereas hoof-epizoochory
had a stronger effect (eight characteristics included five ones with above
75% variation), and fur-epizoochory an even stronger one (nine
characteristics included six ones with above 75% variation). Our results
demonstrate that seed dispersal by ungulates is an ecological filter whose
intensity varies according to the dispersal mechanism considered.
Ungulates can thus play a key role in plant community dynamics and have
implications for plant spatial distribution patterns at multiple scales.