DOI: 10.5061/dryad.931zcrjhz
title: Ecotypic variation in Elymus elymoides productivity and drought resistance traits across the western United States

description: Introduction: Understanding local adaptation to climate is critical for
 managing ecosystems in the face of climate change. While there have been
 many provenance studies in trees, less is known about local adaptation in
 herbaceous species, including the perennial grasses that dominate arid and
 semiarid rangeland ecosystems. Methods and Results: We used a
 common-garden study to quantify variation in growth and drought-resistance
 traits in 99 populations of Elymus elymoides from a broad geographic and
 climatic range in the western United States. Ecotypes from drier sites
 produced less biomass and smaller seeds, and had traits associated with
 greater drought resistance: small leaves with low osmotic potential and
 high integrated water use efficiency (δ13C). Seasonality also influenced
 plant traits. Plants from regions with relatively warm, wet summers had
 large seeds, large leaves, and low δ13C. Irrespective of climate, we also
 observed tradeoffs between biomass production and drought resistance
 traits. Discussion: Together, these results suggest that much of the
 phenotypic variation among E. elymoides ecotypes represents local
 adaptation to differences in the amount and timing of water availability.
 In addition, ecotypes that grow rapidly may be less able to persist under
 dry conditions. Land managers may be able to use this variation to improve
 restoration success by seeding ecotypes with multiple drought resistance
 traits in areas with lower precipitation. The future success of this
 common rangeland species will likely depend on the use of tools such as
 seed transfer zones to match local variation in growth and drought
 resistance to predicted climatic conditions.
description: The data are organized as
 follows: Descriptive and geographic data (columns 1-7); PRISM weather data
 used in PCA (columns 8-22); PCA axes (columns 23-25); Trait variables
 (columns 26-31). Detailed metadata for each column are listed below.
 Please refer to the associated manuscript for a detailed description of
 methods. <b>Collection ID:</b>
 unique identifier for each seed collection <b>Geographic
 description:</b> general description of seed collection
 site <b>Latitude:</b>
 latitude of seed collection site, in decimal degrees <b>Longitude:</b>
 longitude of seed collection site, in decimal degrees <b>Elevation (m):</b>
 elevation of collection site <b>Cultivar:</b>
 identifies seed collected from cultivar or non-cultivar <b>Wild
 collected:</b> identifies seed collected from wild-growing plants or
 plants in cultivation <b>Annual precipitation
 (mm):</b> annual precipitation of seed collection site
 <b>Annual maximum
 temperature:</b> annual maximum temperature of seed collection
 site <b>Annual minimum
 temperature (<sup>o</sup>C):</b> annual minimum
 temperature of seed collection site <b>Spring precipitation
 (mm):</b> spring precipitation at the collection site (season
 defined uniquely for each site) <b>Spring minimum
 temperature (<sup>o</sup>C):</b> spring minimum
 temperature at the collection site (season defined uniquely for each
 site) <b>Spring maximum
 temperature (<sup>o</sup>C):</b> spring maximum
 temperature at the collection site (season defined uniquely for each
 site) <b>Summer precipitation
 (mm):</b> summer precipitation at the collection site (season
 defined uniquely for each site) <b>Summer minimum
 temperature (<sup>o</sup>C):</b> summer minimum
 temperature at the collection site (season defined uniquely for each
 site) <b>Summer maximum
 temperature (<sup>o</sup>C):</b> summer maximum
 temperature at the collection site (season defined uniquely for each
 site) <b>Autumn precipitation
 (mm):</b> autumn precipitation at the collection site (season
 defined uniquely for each site) <b>Autumn minimum
 temperature (<sup>o</sup>C):</b> autumn minimum
 temperature at the collection site (season defined uniquely for each
 site) <b>Autumn maximum
 temperature (<sup>o</sup>C):</b> autumn maximum
 temperature at the collection site (season defined uniquely for each
 site) <b>Winter precipitation
 (mm):</b> winter precipitation at the collection site (season
 defined uniquely for each site) <b>Winter minimum
 temperature (<sup>o</sup>C): </b>winter minimum
 temperature at the collection site (season defined uniquely for each
 site) <b>Winter maximum
 temperature (<sup>o</sup>C):</b> winter maximum
 temperature at the collection site (season defined uniquely for each
 site) <b>PC1 –
 Temperature:</b> PCA axis 1, describes mean annual and seasonal
 temperatures (higher values are warmer) <b>PC2 –
 Precipitation:</b> PCA axis 2, describes mean precipitation (higher
 values are wetter) <b>PC3 –
 Seasonality:</b> PCA axis 3, describes seasonality of both
 precipitation and temperature (higher numbers denote warmer, wetter
 winters, and cooler, drier summers; lower number denote cooler, drier
 winters and warmer, wetter summers) <b>Seed mass (g):
 </b>individual seed mass <b>Leaf</b><b>
 δ</b><b><sup>13</sup></b><b>C
 (</b><b>‰</b><b>): </b>ratio of
 <sup>13</sup>C to <sup>12</sup>C isotope mass in
 leaf tissue, expressed relative to international standard (VPDB)
 <b>Leaf area
 (cm<sup>2</sup>):</b> average projected area of an
 individual leaf <b>Plant biomass
 (g):</b> aboveground plant biomass <b>Leaf osmotic potential
 (MPa): </b>leaf cell solute potential at full hydration
 <b>Leaf dry matter content (g/g):</b> ratio of dry
 leaf mass to leaf mass at full hydration