Data from: Environmental drivers and phylogenetic constraints of growth phenologies across a large set of herbaceous species

1. Because perennial herbs of temperate climates develop their aboveground
parts every year anew, their success critically depends on the timing and
speed of this growth (growth phenology). These parameters can play a role
in species coexistence and may differ along environmental gradients.
Still, we know little about them, as most phenological data come from
observations of flowering and to a lesser degree leafing onset. 2. We
collected data on growth phenology of about 400 perennial herbs in a
botanical garden to make the results independent of local differences in
climatic drivers as much as possible. Using these data, we determined
species-specific parameters of Day of peak growth, Day of maturity, and
two types of growth rates associated with the change in plant size.
Environmental conditions in which these species occur in the field were
assessed using Ellenberg indicator values, which express species'
optima along gradients of moisture, nutrients and temperature. 3. Both
timing and speed of growth estimated in the common garden were affected by
light and moisture conditions of the habitats where the species typically
occur. All parameters showed phylogenetic conservatism. 4. We identified
two relationships among these parameters of growth phenology: (i) species
with early peak growth had high relative growth rates in contrast to late
species; (ii) tall species showed later peak growth than short species
which more often grew early. The first relationship is associated with
survival under forest canopy, where species are selected to grow early and
fast before trees leaf out, which restricts their size. The latter is
associated with (asymmetric) competition for light in open habitats, where
the main selection factor is for tall stature, which cannot be attained
early in the season. 5. Synthesis: We show that large differences in size
growth dynamics among herbaceous species are constrained by a few key
tradeoffs involving height at maturity, rate of growth, and time when
maximum height is attained. These tradeoffs correspond to major selective
forces acting on herbaceous plants in temperate climates.