Overview
Our two experiments both measured aboveground plant biomass at regular
intervals during the growing season at a relatively uncommon level of
temporal detail. From these measurements we could calculate daily RGR
per species throughout the growing season, which provides unique insight
into growth rates and their temporal changes (in contrast, most studies
lack a temporal dimension and measure biomass only at harvest). We used
these measures of RGR to identify when, during the growing season,
differences in RGR best predict competitive outcomes in mixtures,
comparing the high and low fertility treatments in each study. The first
data set comes from a competition experiment with five European
perennial grass species grown under nutrient-limited unproductive and
nutrient-rich productive conditions in the experimental garden of the
University of Zurich, Switzerland (47° 23’ N, 8° 33’ E, and 546 m height
a.s.l.). The second data set lacks independent monocultures but comes
from a field experiment in which nitrogen and phosphorus are added alone
or in combination to a flat alpine meadow at the Alpine Meadow and
Wetland Ecosystems Research Station of Lanzhou University (Azi Branch
Station) in the eastern Tibetan Plateau (33°40’N, 101°51’E, altitude
3500 m a.s.l.), Gansu, China. The growing season typically starts around
April 15 (~ day 106) in Zürich and around May 15
(~ day 136) in Gansu.