Data from: Precipitation and environmental constraints on three aspects of flowering in three dominant tallgrass species

Flower production can comprise up to 70% of aboveground primary production
in grasslands. Yet we know relatively little about how the environment and
timing of rainfall determine flower productivity. Evidence suggests that
deficits or additions of rainfall during phenlologically relevant periods
(i.e. growth, storage, initiation of flowering, and reproduction) can
determine flower production in grasslands. We used long-term data from the
Konza Prairie LTER to test how fire, soil topography, and precipitation
amounts during four phenologically relevant periods of the growing season
constrain three aspects of flowering in three dominant C4 grass species.
Specifically, we examined the probability of flowering, flowering stalk
density, and individual flowering stalk biomass for Andropogon gerardii,
Schizachyrium scoparium and Sorghastrum nutans. We found that each of the
three species responded to the amount of precipitation during
phenologically relevant periods in unique ways. All aspects of A. gerardii
flowering were sensitive to precipitation during the flowering stalk
elongation period (June 20 – Aug 3). The probability of S. nutans
flowering was partly determined by precipitation during the rapid growth
phase (April 21 – June 4), whereas flowering stalk density of this species
depended on rainfall during flowering stalk elongation (June 20 – Aug 3).
In contrast, all aspects of flowering of S. scoparium were relatively
independent of rainfall during any period. Our results demonstrate that
three functionally similar, codominant C4 grass species respond
differently to phenologically relevant precipitation periods. As a result,
drought during any phenological window during the growing season can
adversely impact biomass and flowering production of grasslands via
species-specific reductions in flowering stalk density and biomass.