Data from: Inter- and intraspecific variation in leaf economics traits in wheat and maize

Leaf economics spectrum (LES) trait variation underpins multiple
agroecological processes and many prominent crop yield models. While there
are numerous independent studies assessing trait variation in crops, to
date there have been no comprehensive assessments of intraspecific trait
variation (ITV) in LES traits for wheat and maize: the world’s most
widespread crops. Using trait databases and peer-reviewed literature, we
compiled over 700 records of specific leaf area (SLA), maximum
photosynthetic rates (Amax), and leaf nitrogen (N) concentrations, for
wheat and maize. We evaluated intraspecific LES trait variation, and
intraspecific trait-environment relationships. While wheat and maize
occupy the upper 90th percentile of LES trait values observed across a
global species pool, ITV ranged widely across the LES in wheat and maize.
Fertilization treatments had strong impacts on leaf N, while plant
developmental stage (here standardized as the number of days since
planting) had strong impacts on Amax; days since planting, N
fertilization, and irrigation all influenced SLA. When controlling for
these factors, intraspecific responses to temperature and precipitation
explained 39.4 and 43.7% of the variation in Amax and SLA, respectively,
but only 5.4% of the variation in leaf N. Despite a long history of
domestication in these species, ITV in wheat and maize among and within
cultivars remains large. ITV is a critical consideration to refine
regional- to global models of agroecosystem structure, function, and food
security. Considerable opportunities and benefits exist for consolidating
a crop trait database for a wider range of domesticated plant species.