Ozone affects global food supplies
BY JULIE SEAMERTHURSDAY, AUGUST 28, 2008
Rising fuel prices, drought and heat waves have been hot topics in the media all around the world and the root of our environmental problems is said to be rising ozone levels.
According to research by William Manning (a Professor of plant soil and insect sciences at the University of Massachusetts Amherst), rising background levels of ozone in the atmosphere are the likely contributor to poor yield in important food crops. This includes wheat and soybeans.
Manning says the ozone standard set by the EPA (Environment Protection Agency) in the United States may not be strict enough to protect plants as it is based according to human health. "Plants are more sensitive to ozone than people, and a slight increase in exposure can have a large impact on productivity".
While emission controls on cars have been successful in reducing short periods of high ozone levels called peaks, average concentrations (called the background level) are increasing as polluted air masses from Asia travel across the globe. In Europe and the US background levels are not between 20 and 45 parts per billion but are expected to rise to 42-84 parts per billion by 2100.
Studies conducted by Manning using oilseed rape which is a member of the cabbage family and produces one-third of the vegetable oil in China, showed that exposure to elevated ozone reduced the biomass (size and weight) of the plants by up to 20%. This resulted in reduced production of seeds and oil.
These studies also showed that wheat is more sensitive to ozone than rice, with radishes, broccoli and soybeans also demonstrating higher react ability to atmospheric changes.
It has been found that plants can limit ozone uptake and damage for short periods by reducing the size of their pores on leaves. However this also reduces carbon dioxide uptake which is a necessary component for the process of photosynthesis. Chronic exposure negatively impacts photosynthesis thereby affecting plant growth and yields. And although plants normally produce antioxidants to counter this effect, with too much ozone, leaf injury occurs exceeding the plant's ability to achieve this.
Manning noted that "plants exposed to a ozone levels that peaked in the late afternoon suffered more damage than plants exposed to a steady ozone concentration throughout the day. This shows that current ozone standards that rely on average concentrations would underestimate crop losses".
This news may seem overwhelming, however we can all try doing our part to reducing the accelerating ozone problem by taking the train to work instead of driving the car, trying to monitor and reduce our carbon footprint, and by supporting efforts in our local area for the environment, be it tree-planting or recycling of rubbish. Every bit counts!
Abundant Earth/Health Brands Australia is a company who cares about the environment. Committed to reducing our greenhouse emissions we are actively working on our own sustainability program which covers all aspects of how we run and manage our business. Watch this space for updates on our progress!
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