Data from: Quantifying seed rain patterns in a remnant and a chronosequence of restored tallgrass prairies in north central Missouri

Seed rain is an influential process related to plant community diversity,
composition, and regeneration. However, knowledge of seed rain patterns is
limited to those observed in forests and late-assembling grasslands, which
might not reflect early-assembling communities such as newly restored
grasslands. Resolving this gap in our understanding provides further
insight into the role of seed dispersal.  Here, we measured seed
rain in a remnant tallgrass prairie, which was the site of the
foundational grassland seed rain study in 1978, and a nearby
chronosequence of tallgrass prairie restorations. We sought to determine
how the quantity, seed mass traits, timing, diversity, and composition of
seed rain changed (1) long-term and (2) during community assembly. To do
so, we deployed artificial turf grass seed traps into 2-year-old,
5-6-year-old, and 15-year-old restored prairies and the remnant prairie,
replacing traps every two weeks from May to December 2019. We captured
over twice the density and richness of seed rain in the remnant prairie in
2019 compared to 1978. We also found that seed rain patterns changed as
prairies aged, with each prairie possessing a distinct community of
dispersing species. Significantly more seeds, seed biomass, and species
were captured in the youngest restored prairie. However, seed mass traits
were similar in all prairies. Except for composition, all other seed rain
metrics in the oldest restoration were eventually comparable to the
remnant prairie. Synthesis and Applications: Our results revealed that
grasslands, notably young prairies, produce larger quantities of seed rain
than previously known (124,806 seeds m-2 year –1, 97.24 g m-2 year –1),
and seed input in all sampled prairies far exceeded restoration broadcast
seeding densities. We further found that decreases in seed rain quantity
across the chronosequence did not correspond with increases in seed mass,
suggesting a lack of tradeoffs between these metrics. Furthermore,
tallgrass prairie restorations have not replicated the composition of seed
rain seen in remnant systems. Increasing restoration seeding rates of
desirable species may be needed to meet composition goals since current
rates may not compete with the propagule pressure of undesirable species
found in newly restored prairies.