GOTHENBURG, Sweden, June 12 (UPI) -- Increased carbon dioxide in the air decreases plants' ability to absorb nitrogen, even in plants whose growth has not been affected by the change, according to a new study.
The University of Gothenburg study found the effect widely held true in field studies in eight countries and on four continents in crops, grasslands and forests.
"The findings of the study are unequivocal," said Johan Uddling, a senior lecturer at the Department of Biological and Environmental Sciences at the University of Gothenburg, in a press release. "The nitrogen content in the crops is reduced in atmospheres with raised carbon dioxide levels in all three ecosystem types. Furthermore, we can see that this negative effect exists regardless of whether or not the plants' growth increases, and even if fertilizer is added. This is unexpected and new."
It was previously thought that as plants grew, increased levels of carbon dioxide affected how much nitrogen plants could absorb, and that it may effect their growth. The new research shows, however, that growth of plants and nitrogen the plants absorb are not related.
Researchers found that increased levels of carbon dioxide affected the plants ability to absorb nitrogen even when additional sources were in the soil.
The study is published in the journal Global Change Biology.
