Page Banner

United States Department of Agriculture

Agricultural Research Service

Research Project: IDENTIFYING AND MANIPULATING DETERMINANTS OF PHOTOSYNTHATE PRODUCTION AND PARTITIONING

Location: Global Change and Photosynthesis Research Unit

Title: Impacts of herbaceous bioenergy crops on atmospheric volatile organic composition and potential consequences for global climate change

Authors
item Miresmailli, S -
item Zeri, M -
item Zangerl, A -
item Bernacchi, Carl
item Berenbaum, M -
item Delucia, E -

Submitted to: Global Change Biology Bioenergy
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: May 22, 2012
Publication Date: N/A

Interpretive Summary: The introduction of new crops to agroecosystems can change the chemistry of the atmosphere by altering the bouquet of plant-derived chemicals known as biogenic volatile organic compounds (BVOCs). BVOCs are low molecular weight chemicals that are generally used by plants for defense, pollination and communication purposes. They also influence the atmosphere as potential greenhouse gases and pollutants. In this study, we compared BVOC emissions from three potential biofuel crops and estimated their theoretical impacts on bioenergy agroecosystems. The crops chosen were miscanthus, switchgrass and an assemblage of prairie species (mix of ~28 species). The concentration of the chmicals was different within and above plant canopies. All crops produced higher levels of the chemicals at the upper canopy level. Miscanthus produced lower amounts of volatiles compared to other crops. The chemical composition of volatiles also differed significantly across all three plant canopies. BVOCs from miscanthus were depleted in terpenoids (an important group of plant chemicals) relative to the other vegetation types. The amount of carbon that released from these plants in form of BVOCs, calculated using the flux-gradient method, was significantly higher in the prairie assemblage compared to miscanthus and switchgrass. The released carbon was approximately three orders of magnitude lower than the net of carbon measured over the same fields. Extrapolation of our findings to the landscape scale leads us to suggest that the widespread adoption of biofuel crops can potentially alter the composition of BVOCs in the atmosphere, thereby influencing its warming potential, the formation of pollutants and interactions between plants and arthropods.

Technical Abstract: The introduction of new crops to agroecosystems can change the chemical composition of the atmosphere by altering the bouquet of plant-derived biogenic volatile organic compounds (BVOCs). BVOCs are low molecular weight secondary metabolites that are generally used by plants for defense, pollination and communication. They also influence the atmosphere as potential greenhouse gases and precursors of particulate matter. In this study, we compared BVOC emissions from three potential biofuel crops and estimated their theoretical impacts on bioenergy agroecosystems. The crops chosen were miscanthus (Miscanthus x giganteus), switchgrass (Panicum virgatum) and an assemblage of prairie species (mix of ~28 species). The concentration of BVOCs was different within and above plant canopies. All crops produced higher levels of emissions at the upper canopy level. Miscanthus produced lower amounts of volatiles compared to other grasses. The chemical composition of volatiles differed significantly across all three plant canopies. BVOCs from miscanthus were depleted in terpenoids relative to the other vegetation types. The carbon flux via BVOC emissions, calculated using the flux-gradient method, was significantly higher in the prairie assemblage compared to miscanthus and switchgrass. The BVOC carbon flux was approximately three orders of magnitude lower than the net fluxes of carbon measured over the same fields by eddy covariance systems. Extrapolation of our findings to the landscape scale leads us to suggest that the widespread adoption of biofuel crops can potentially alter the composition of BVOCs in the atmosphere, thereby influencing its warming potential, the formation of atmospheric particulates, and interactions between plants and arthropods.

Last Modified: 4/23/2014
Footer Content Back to Top of Page