Large and non-spherical seeds are less likely to form a persistent soil seed bank

There is some evidence that seed traits can affect the long-term
persistence of seeds in the soil. However, findings on this topic have
differed between systems. Here, we brought together a worldwide database
of seed persistence data for 1474 species to test the generality of seed
mass-shape-persistence relationships. We found a significant trend for low
seed persistence to be associated with larger and less spherical seeds.
However, the relationship varied across different clades, growth forms and
species ecological preferences. Specifically, relationships of seed
mass-shape-persistence were more pronounced in Poales than in other order
clades. Herbaceous species that tend to be found in sites with low soil
sand content and precipitation have stronger relationships between seed
shape and persistence than in sites with higher soil sand content and
precipitation. For the woody plants, the relationship between persistence
and seed morphology was stronger in sites with high soil sand content and
low precipitation than in sites with low soil sand content and higher
precipitation. Improving ability to predict the soil seed bank formation
process, including burial and persistence, could benefit the utilization
of seed morphology-persistence relationships in management strategies for
vegetation restoration and controlling species invasion across diverse
vegetation types and environments.