title: The influence of drought and heat stress on long-term carbon fluxes of bioenergy crops grown in the Midwestern USA.
abstract: Perennial grasses are promising feedstocks for bioenergy production in the Midwestern USA. Few experiments have addressed how drought influences their carbon fluxes and storage. This study provides a direct comparison of ecosystem-scale measurements of carbon fluxes associated with miscanthus (Miscanthus × giganteus), switchgrass (Panicum virgatum), restored native prairie and maize (Zea mays)/soybean (Glycine max) ecosystems. The main objective of this study was to assess the influence of a naturally occurring drought during 2012 on key components of the carbon cycle and plant development relative to non-extreme years. The perennials reached full maturity 3-5 years after establishment. Miscanthus had the highest gross primary production (GPP) and lowest net ecosystem exchange (NEE) in 2012 followed by similar values for switchgrass and prairie, and the row crops had the lowest GPP and highest NEE. A post-drought effect was observed for miscanthus. Over the duration of the experiment, perennial ecosystems were carbon sinks, as indicated by negative net ecosystem carbon balance (NECB), while maize/soybean was a net carbon source. Our observations suggest that perennial ecosystems, and in particular miscanthus, can provide a high yield and a large potential for CO2 fixation even during drought, although drought may negatively influence carbon uptake in the following year, questioning the long-term consequence of its maintained productivity.
authors.affiliation: Department of Plant Biology, University of Illinois, Urbana, IL, 61801, USA.|Energy Bioscience Institute - Carl R. Woese Institute for Genomic Biology, University of Illinois, Urbana, IL, 61801, USA.
authors.forename: Eva
authors.initials: E
authors.lastname: Joo
authors.affiliation: Great Lakes Bioenergy Research Center, W.K. Kellogg Biological Station, Michigan State University, Hickory Corner, MI, 49060, USA.
authors.forename: Mir Zaman
authors.initials: MZ
authors.lastname: Hussain
authors.affiliation: National Center for Monitoring and Early Warning of Natural Disasters (CEMADEN), 12.247-016, São José dos Campos, SP, Brazil.
authors.forename: Marcelo
authors.initials: M
authors.lastname: Zeri
authors.affiliation: Energy Bioscience Institute - Carl R. Woese Institute for Genomic Biology, University of Illinois, Urbana, IL, 61801, USA.
authors.forename: Michael D
authors.initials: MD
authors.lastname: Masters
authors.affiliation: Department of Plant Biology, University of Illinois, Urbana, IL, 61801, USA.|Energy Bioscience Institute - Carl R. Woese Institute for Genomic Biology, University of Illinois, Urbana, IL, 61801, USA.
authors.forename: Jesse N
authors.initials: JN
authors.lastname: Miller
authors.affiliation: Department of Plant Biology, University of Illinois, Urbana, IL, 61801, USA.|Energy Bioscience Institute - Carl R. Woese Institute for Genomic Biology, University of Illinois, Urbana, IL, 61801, USA.
authors.forename: Nuria
authors.initials: N
authors.lastname: Gomez-Casanovas
authors.affiliation: Department of Plant Biology, University of Illinois, Urbana, IL, 61801, USA.|Energy Bioscience Institute - Carl R. Woese Institute for Genomic Biology, University of Illinois, Urbana, IL, 61801, USA.
authors.forename: Evan H
authors.initials: EH
authors.lastname: DeLucia
authors.affiliation: Department of Plant Biology, University of Illinois, Urbana, IL, 61801, USA.|Energy Bioscience Institute - Carl R. Woese Institute for Genomic Biology, University of Illinois, Urbana, IL, 61801, USA.|Global Change and Photosynthesis Research Unit, USDA ARS, Urbana, IL, 61801, USA.
authors.forename: Carl J
authors.initials: CJ
authors.lastname: Bernacchi
mesh_terms: D056804:Biofuels; D018533:Biomass; D002245:Carbon Dioxide / Q000378:metabolism*; D055864:Droughts; D018869:Heat-Shock Response; D007087:Illinois; D006109:Poaceae / Q000378:metabolism*
chemical_list: D056804:Biofuels; D002245:Carbon Dioxide
keywords: carbon balance; ecosystem development; eddy covariance; gross primary production; maize; miscanthus; net ecosystem exchange; prairie; switchgrass