The influence of drought and heat stress on long‐term carbon fluxes of bioenergy crops grown in the Midwestern USA. (23rd June 2016)

• Record Type: Journal Article
• Authors: Joo, Eva; Hussain, Mir Zaman; Zeri, Marcelo; Masters, Michael D.; Miller, Jesse N.; Gomez‐Casanovas, Nuria; DeLucia, Evan H.; Bernacchi, Carl J.
• Is Part Of: Plant, cell and environment. Volume 39:Number 9(2016)
• Page Start: 1928
• Page End: 1940
• Publication Date: 2016-06-23
• Subjects: maize -- miscanthus -- switchgrass -- carbon balance -- ecosystem development -- eddy covariance -- gross primary production -- net ecosystem exchange -- prairie; Plant physiology -- Periodicals; Plant cells and tissues -- Periodicals; Plant communities -- Periodicals; 581.105
• DOI: 10.1111/pce.12751
• Languages: English
• ISSNs: 0140-7791

Abstract

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. Abstract : Perennial grasses have been identified as being, in many ways, ideal feedstocks for bioenergy production. Yet side‐by‐side comparisons of key carbon fluxes and pools, particularly in response to climate extremes, for perennial grasses compared with the traditional row crops that they replace are needed. This research represents a long‐term eddy covariance experiment, encompassing a severe drought, where three perennial ecosystems are compared with traditional row crops. The results show that perennial ecosystems are more resilient to drought than row crops in terms of both carbon uptake and storage and that a post‐drought effect may be more likely in a perennial relative to annual ecosystem.