Data from: Seed and seedling traits have strong impacts on establishment of a perennial bunchgrass in invaded semi-arid systems

1. Many restoration projects use seeds to found new populations, and
understanding phenotypic traits associated with seedling establishment in
disturbed and invaded communities is important for restoration efforts
worldwide. Focusing on the perennial grass Elymus elymoides, a native
species common to sagebrush steppe communities in the Western United
States, we asked if seed and seedling traits could predict field
establishment. 2. We collected seeds from 34 populations from the western
Great Basin. In greenhouse studies, we measured variation in seed and
seedling characteristics of wild populations and one cultivar. We also
quantified abiotic conditions at the collection location and asked if
these characteristics predicted survival and other fitness metrics at five
planting sites. Planting sites were all near-monocultures of the invasive
annual grass Bromus tectorum, and all sites experienced similar,
below-average precipitation during the experiment. 3. Phenotypic traits
were strongly correlated with performance across all sites, with
remarkably high predictive power. Seeds from populations with longer
roots, larger seeds, and earlier emergence were significantly more likely
to survive the first growing season (R2 = 0.66, P <0.0001). In
contrast, while some abiotic variables at the collection location (e.g. 30
year average summer precipitation and fall minimum temperatures) were
associated with field performance at some sites, abiotic variables
explained less variation in performance than traits (average R2 = 0.22).
Despite the low predictive power of abiotic variables, populations that
performed best at each field site were from locations with climate
variables similar to planting sites. 4. Synthesis and applications. The
best seed sources for restoration of E. elymoides in invaded sites were
populations with longer roots, larger seeds, and earlier emergence. These
easily-measured traits were strong predictors of survival in disturbed
field sites. While the most successful populations were found in areas
with similar abiotic conditions as planting sites, there was phenotypic
variation even among populations originating from locations with similar
conditions. Thus, our results indicate that abiotic conditions are
important considerations when selecting seeds, but these conditions may
not sufficiently predict which populations will establish. Understanding
population differences in seedling functional traits can improve
predictions of restoration success.