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ARS Home » Plains Area » Temple, Texas » Grassland Soil and Water Research Laboratory » Research » Publications at this Location » Publication #294747
Title: Growth and physiological plasticity among differentially adapted genotypes of a widespread C4 grass under altered precipitation

Author
item ASPINWALL, MIKE - Western Sydney University
item TAYLOR, SAM - University Of Texas
item LOWRY, DAVID - University Of Texas
item KHASANOVA, ALBINA - University Of Texas
item BONNETTE, JASON - University Of Texas
item WHITAKER, BRIANA - University Of Texas
item JOHNSON, NICK - University Of Texas
item HAWKES, CHRISTINE - University Of Texas
item JUENGER, TOM - University Of Texas
item Fay, Philip

Submitted to: Ecological Society of America Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 3/31/2013
Publication Date: 8/4/2013
Citation: Aspinwall, M., Taylor, S., Lowry, D., Khasanova, A., Bonnette, J., Whitaker, B., Johnson, N., Hawkes, C., Juenger, T., Fay, P.A. 2013. Growth and physiological plasticity among differentially adapted genotypes of a widespread C4 grass under altered precipitation. In: Proceedings of the Ecological Society of America Abstracts, Aug. 4-9, 2013, Minneapolis, Minnesota. 2013 CDROM.

Interpretive Summary:

Technical Abstract: Background/Question/Methods Variation in precipitation expected with climate change may impact plant fitness and alter ecosystem dynamics by modifying species phenology, productivity, and physiology. Species responses to varied precipitation will depend in part on plastic responses of genotypes adapted to local climate. Here, we examined the effects of variable precipitation on genotype reproductive phenology, aboveground net primary productivity (ANPP), leaf area index (LAI), and leaf functional traits in Panicum virgatum L. (switchgrass), an ecologically dominant tallgrass prairie species. We hypothesized that plastic responses of genotypes (genotype plasticity index) to varied precipitation would depend upon genotype climate of origin. To test this hypothesis, we collected nine P. virgatum genotypes adapted to different climates and grew them under rainout shelters located at two sites in Central Texas, differing in soil depth (deep, shallow). The genotypes received six experimental precipitation treatments, representing the driest to wettest years (based on mean annual precipitation) for each site, in a randomized complete block design. Days to flowering (DF), LAI, and ANPP were measured in all treatments, and leaf water potentials ('), net photosynthetic rates (ACO2), leaf nitrogen (N), and leaf mass area (LMA) were measured in the low, mean, and high precipitation treatments during June and August. Results/Conclusions Decreased precipitation delayed DF up to 21 days (P<0.001), reduced LAI 9% - 37% (0.5