Plant body clock observed in tropical forest research

Sep 26, 2011

(PhysOrg.com) -- Predictions of the ground-level pollutant ozone will be more accurate in future according to research published today by environment scientists at research centres including the University of Birmingham in the journal Nature Geoscience.

Ozone is formed in the atmosphere when like isoprene – which is emitted by some plants - react with nitrogen oxides from car engines or industry. at ground level is very harmful to human health, may decrease crop yields, and is a greenhouse gas.

The research team, led by Professor Nick Hewitt at the University of Lancaster’s Environment Centre, have found that the rate at which plants emit isoprene is influenced by their body clock or circadian rhythm.

This 24-hour circadian rhythm, which also controls leaf movement and respiration in plants, has never before been observed operating in concert in a stand of trees. This discovery alters current estimates of plant-derived isoprene emissions. Ground-level ozone concentrations, calculated using the new isoprene emissions, are then closer to observed concentrations, going some way to resolve a long-standing deficiency in computer simulation of ground-level ozone.

Rob MacKenzie of the University of Birmingham, who led the initial ozone modelling studies, said: “Using various models of atmospheric chemistry we show that this more complete understanding of the processes controlling isoprene emissions yields a better predictive capability for ground-level ozone, especially in isoprene-sensitive regions of the world.”

These regions include the south eastern US, the Mediterranean, the Middle East, parts of South East Asia and Japan.

Professor Hewitt said: “We spend billions of pounds trying to control ozone – for example, by putting catalytic convertors in new cars in order to prevent emissions of oxides of nitrogen. This discovery of the circadian rhythm operating on the forest canopy scale is another step in better understanding ozone and improving our models of the .”

The researchers examined measurements of isoprene made above tropical rainforest and oil palm plantations in Sabah in Malaysia, carried out as part of a £2.5m UK/Malaysian scientific research project.

Eiko Nemitz of the UK Centre for Ecology and Hydrology said: “Our flux measurements show that emissions of isoprene are under circadian contro, strongly in the oil palm plantation and less strongly in the rainforest. These ecosystems therefore emit less isoprene than current emissions models predict.”

Using computer simulations from the National Centre for Atmospheric Research in Colorado, the team then compared their simulated ground-level ozone with real-life ozone measurements at 290 atmospheric monitoring sites in the US. They found that their model accuracy significantly improved when it included circadian control of isoprene .

Explore further: TRMM satellite sees Tropical Storm Phanfone fragmented

More information: Ground-level ozone influenced by circadian control of isoprene emissions, doi:10.1038/ngeo1271

Provided by University of Birmingham

not rated yet

Related Stories

Vital role for bacteria in climate-change gas cycle

Mar 29, 2010

Isoprene is a Jekyll-and-Hyde gas that is capable of both warming and cooling the Earth depending on the prevailing conditions. It is an important industrial gas, necessary for the manufacture of important ...

EPA proposes new ozone standards

Jun 21, 2007

The U.S. Environmental Protection Agency announced a proposal Thursday to strengthen the nation's air quality standard for ground-level ozone.

Climate change increases the risk of ozone damage to plants

Jun 30, 2011

Ground-level ozone is an air pollutant that harms humans and plants. Both climate and weather play a major role in ozone damage to plants. Researchers at the University of Gothenburg, Sweden, have now shown that climate change ...

Recommended for you

Tropical Storm Rachel dwarfed by developing system 90E

4 hours ago

Tropical Storm Rachel is spinning down west of Mexico's Baja California, and another tropical low pressure area developing off the coast of southwestern Mexico dwarfs the tropical storm. NOAA's GOES-West ...

NASA ocean data shows 'climate dance' of plankton

7 hours ago

The greens and blues of the ocean color from NASA satellite data have provided new insights into how climate and ecosystem processes affect the growth cycles of phytoplankton—microscopic aquatic plants ...

Glaciers in the grand canyon of Mars?

9 hours ago

For decades, planetary geologists have speculated that glaciers might once have crept through Valles Marineris, the 2000-mile-long chasm that constitutes the Grand Canyon of Mars. Using satellite images, ...

NASA support key to glacier mapping efforts

9 hours ago

Thanks in part to support from NASA and the National Science Foundation, scientists have produced the first-ever detailed maps of bedrock beneath glaciers in Greenland and Antarctica. This new data will help ...

User comments : 0