Phenotypic, fitness and environmental data in support of the publication: selection favors adaptive plasticity in a long-term reciprocal transplant experiment

Spatial and temporal environmental variation can favor the evolution of
adaptive phenotypic plasticity, such that genotypes alter their phenotypes
in response to local conditions to maintain fitness across heterogeneous
landscapes. When individuals show greater fitness in one habitat than
another, asymmetric migration can restrict adaptation in the lower quality
environment. In these cases, selection is predicted to favor traits that
enhance fitness in the higher-quality habitat at the expense of fitness in
the marginal habitat. Here, we test whether plasticity is
adaptive in a system regulated by demographic source-sink
dynamics. Vaccinium elliottii (Ericaceae) occurs in dry upland
and flood-prone bottomland forests throughout the southeastern United
States, and shows patterns consistent with source-sink dynamics. We
conducted a multi-year field experiment to evaluate whether plasticity in
foliar morphology increases survival and lifespan. Both across and within
habitats, selection favored plasticity in specific leaf area, stomatal
density, and leaf size. Stabilizing selection acted on plasticity in
stomatal density within habitats, suggesting that extreme levels of
plasticity are disadvantageous. Thus, even in systems driven by
source-sink dynamics, temporal and spatial variation in conditions across
the landscape and within habitat types can favor the evolution of
plasticity.