Isoprene from Plants and Atmospheric Chemistry

Clive G. Jones
Institute of Ecosystem Studies

Isoprene is a C-5 hydrocarbon emitted from leaves of many plant species. Isoprene entering the atmosphere reacts with hydroxyl radicals, and is a key regulator of the oxidative capacity of the atmosphere. About 30% of global carbon monoxide comes from isoprene oxidation. Isoprene affects the atmospheric residence time of methane, a major greenhouse gas influencing global temperature. Isoprene is also major factor in the formation of ozone pollution in the lower atmosphere. For example, isoprene is responsible for the blue haze of the Smoky and Blue Ridge Mountains. Understanding what controls isoprene emission from plants is critical for improving models of atmospheric chemistry and global climate. Isoprene emissions are known to be controlled by ambient leaf light and temperature, and to be influenced by leaf specific weight and nitrogen content. However, these factors account for only a small fraction of the observed variation in isoprene emissions from plants. The goals of Dr. Jones' and collaborators' research are to identify the other major sources of variation in isoprene emissions, and find out what causes this variation. Identifying the causes of variation should help to better predict isoprene emissions into the atmosphere. Work with oaks and cottonwood is focusing on diurnal patterns, inter-plant variability, and whole plant carbon balance — related to plant stress and damage — as major sources of variation in isoprene emissions.

Collaborators
Ms. Jennifer Funk, Graduate Student, SUNY Stony Brook, NY
Dr. Manuel Lerdau, IES Visiting Scientist, SUNY Stony Brook, NY

Publication
Funk, J. L., Jones, C. G., and Lerdau, M. T. 199x. Whole plant controls on isoprene emission from Populus deltoides. Oecologia (in press).