Genotypic variation in traits controlling carbon flux responses to precipitation in switchgrass

Authors: Fay, Philip; REICHMANN, LARA - University Of Texas; ASPINWALL, MICHAEL - University Of Sydney; Polley, Herbert; Gibson, Anne; KHASANOVA, ALBINA - University Of Texas; WHITAKER, BRIANA - University Of Texas; LOWRY, DAVID - University Of Texas; TAYLOR, SAM - University Of Texas; HAWKES, CHRISTINE - University Of Texas; Kiniry, James; JUENGER, TOM - University Of Texas

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 9/1/2013
Publication Date: 9/10/2013
Citation: Fay, P.A., Reichmann, L.G., Aspinwall, M.J., Polley, H.W., Gibson, A.E., Khasanova, A., Whitaker, B., Lowry, D., Taylor, S., Hawkes, C., Kiniry, J.R., Juenger, T. 2013. Genotypic variation in traits controlling carbon flux responses to precipitation in switchgrass. In: Proceedings of the Switchgrass II Conference, September 10-12, 2013, Madison, Wisconsin. 2013.

Interpretive Summary:

Technical Abstract: Fluxes of carbon in terrestrial ecosystems are key indicators of their productivity and carbon storage potential. Ecosystem fluxes will be impacted by climate change, especially changes in rainfall amount. Fluxes are also related to plant traits, including leaf photosynthesis (ACO2), leaf area index (LAI), and aboveground biomass (AGB). Here we demonstrate genotypic variation in traits controlling net ecosystem exchange (NEE) in the C4 grass Panicum virgatum L. (switchgrass). Nine genotypes of P. virgatum were established under a rainfall exclusion shelter in central Texas, USA, and watered to emulate dry, average and wet years in a randomized complete blocks design. NEE, gross primary production (GPP), ecosystem respiration (Re), and plant traits were measured during rapid tiller growth (June) and near peak growth (August), and AGB was measured at plant senescence. NEE increased 22-83% with increasing rainfall (0.003