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United States Department of Agriculture

Agricultural Research Service

Title: Climate Change, C02 and Ragweed

Author
item Ziska, Lewis

Submitted to: Allergy and Immunology Meeting American Academy
Publication Type: Abstract Only
Publication Acceptance Date: March 18, 2001
Publication Date: N/A

Technical Abstract: Although environmental factors such as precipitation and temperature are recognized as influencing pollen production, the impact of rising atmospheric carbon dioxide concentration (CO2) on the potential growth and pollen production of hay-fever-inducing plants is unknown. Growth and pollen production of common ragweed (ambrosia artemisiifolia L.) at current concentration (370 ppm) and a projected concentration (600 ppm) increased ragweed pollen production by 131 and 320 percent, respectively, compared to plants grown at pre industrial CO2 (280 ppm). The observed stimulations of pollen production from the pre industrial CO2 concentration were due to an increase in the number (at 370 ppm) and number and size (at 600 ppm) of floral spikes. Overall, floral weight as a percentage of total plant weight decreased from 21 percent to 13 percent, while investment in pollen increased from 3.6 to 6 percent between 280 and 600 ppm CO2. These results suggest that the increase in atmospheric CO2 from pre-industrial times has increased potential ragweed growth and reproductive success as well as public health.

Last Modified: 8/22/2014
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