Environmentally induced dynamics between intraindividual variation and trait means across vegetative, phenological, and floral traits.

PREMISE: Intraindividual variation in reiterated structures (e.g., leaves) represents an important dimension of phenotypic variation that contributes to functional diversity and the dynamics of ecological communities. It can be expressed differently across plant traits, but how environmental drivers affect intraindividual variation in different trait types remains unknown. METHODS: Here we subjected Galium odoratum to drought and shading treatments with a full-factorial experimental design to investigate environmental induction of intraindividual variation in vegetative, phenological, and floral traits and the dynamic relationships between trait mean responses and their variation. RESULTS: Intraindividual variation differed in magnitude between trait types, with vegetative traits having the highest variation and floral traits the lowest. Intraindividual variation differed among the environmental treatments with floral traits having the highest variation under control conditions, whereas vegetative traits had the highest amount of variation under the combined drought and early-shading treatment. Relationships between intraindividual variation and trait means varied across most traits and treatments, indicating environmentally induced dynamics in trait expressions. CONCLUSIONS: Intraindividual variation was environmentally inducible and dynamic depending on the treatment, suggesting that plastic responses in intraindividual variation may be an important component for mechanistic adjustments of plants to environmental stresses.