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ARS Home » Plains Area » Fort Collins, Colorado » Center for Agricultural Resources Research » Water Management and Systems Research » Research » Publications at this Location » Publication #390615

Research Project: Improving the Sustainability of Irrigated Farming Systems in Semi-Arid Regions

Location: Water Management and Systems Research

Title: Physiological trait networks enhance understanding of crop growth and water use in contrasting environments

item Gleason, Sean
item Barnard, David
item Green, Timothy
item MACKAY, DAVID - University At Buffalo
item WANG, DIANE - Purdue University
item Ainsworth, Elizabeth - Lisa
item ALTENHOFEN, JON - Northern Colorado Water Conservancy District
item Banks, Garrett
item BRODRIBB, TIMOTHY - University Of Tasmania
item COCHARD, HERVÉ - Inrae
item Comas, Louise
item COOPER, MARK - University Of Queensland
item CREEK, DANIELLE - Inrae
item DeJonge, Kendall
item DELZON, SYLVAIN - Inrae
item FRITSCHI, FELIX - University Of Missouri
item HAMMER, GRAEME - University Of Queensland
item Hunter, Cameron
item LOMBARDOZZI, DANICA - National Center For Atmospheric Research (NCAR)
item MESSINA, CARLOS - Corteva Agriscience
item OCHELTREE, TROY - Colorado State University
item Stevens, Bo
item STEWART, JARED - US Department Of Agriculture (USDA)
item VADEZ, VINCENT - International Crops Research Institute For Semi-Arid Tropics (ICRISAT) - India
item Wenz, Joshua
item WRIGHT, IAN - Macquarie University
item Zhang, Huihui

Submitted to: Plant, Cell & Environment
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/20/2022
Publication Date: 6/23/2022
Citation: Gleason, S.M., Barnard, D.M., Green, T.R., Mackay, D.S., Wang, D.R., Ainsworth, E.A., Altenhofen, J., Banks, G.T., Brodribb, T.J., Cochard, H., Comas, L.H., Cooper, M., Creek, D., DeJonge, K.C., Delzon, S., Fritschi, F.B., Hammer, G., Hunter, C., Lombardozzi, D., Messina, C.D., Ocheltree, T., Stevens, B.M., Stewart, J.J., Vadez, V., Wenz, J.A., Wright, I.J., Zhang, H. 2022. Physiological trait networks enhance understanding of crop growth and water use in contrasting environments. Plant, Cell & Environment. 45(9):2554-2572.

Interpretive Summary: Plant functioning arises from a complex network of structural and physiological traits (trait "networks"). For example, photosynthesis depends on the uptake (through roots), transport (through xylem), and exchange (through stomata) of water for atmospheric CO2. These coordinated processes are the outcome of closely linked root, xylem, and stomatal traits. In this study we used a plant growth model (the Terrestrial Regional Ecosystem Exchange Simulator; TREES) that was parameterized with measured plant traits relating to water access, water transport, and the exchange of water for CO2. Our goal was to determine if models such as TREES have potential to identify beneficial trait networks in maize grown in contrasting environments. We uncovered two trait networks likely to confer improved performance when water limits plant growth (particularly late-season growth) vs when water is non-limiting. These two trait networks can be understood by their aggregate effect on water use and water conservation. The efficacy of these trait networks arose from climate differences among sites (precipitation amount, precipitation timing, VPD, temperature, and soil texture), aka “envirotype”. This outcome suggests that, although site-specific climates need to be carefully considered when choosing/designing crop species for a given location, that at least in many instances we might expect similar trait networks to improve performance when water limits plant growth versus when it does not.

Technical Abstract: Plant functioning arises from a complex network of structural and physiological traits. Explicit representation of these traits, as well as their connections with other biophysical processes, is required to advance our understanding of plant functioning and to predict plant-soil-climate interactions. We used a modified version of the Terrestrial Regional Ecosystem Exchange Simulator (TREES) to evaluate physiological trait networks in maize. Maize net primary productivity (NPP) and grain yield were simulated across five environments with contrasting growing season precipitation, vapor pressure deficit, and temperature. Simulations of high precipitation environments favored (higher NPP & grain yield) trait networks conferring high water use strategies: deep roots (often), high xylem hydraulic conductivity, “risky” stomatal regulation (high stomatal conductance at low leaf water potential), and high maximal leaf area index. In contrast, environments with low late season precipitation (during reproductive development) favored trait networks conferring water conservation: deep roots, high embolism resistance, and “conservative” stomatal regulation (low stomatal conductance at low leaf water potential). As such, the trait networks conferring improved performance in scenarios with high water availability were nearly the opposite of the trait networks conferring improved performance in the dry scenarios. Water conserving trait networks were improved by including traits facilitating fast early season root growth, particularly when deep soil water was available later in the season. Our results indicate that evaluating single traits in isolation of other biologically aligned traits is not an effective strategy for predicting plant performance. Rather, an approach that allows for the evaluation of physiological traits and their interactions (i.e., networks) has potential to improve crop growth predictions in different environments. Such an approach should aim to identify a range of trait combinations contributing to superior yield as well as climate variation among years and among target sites.