Every once in a while we hear of an unexpected consequence of pollution or climate change and this one is particularly interesting. Scientists at Loughborough University in England found that an increased level of nitrogen in rainfall over bogs in Northern Europe was causing carnivorous plant species to cut back or stop consuming insect prey because they were now getting more nitrogen through their roots.
Air pollution from the burning of fossil fuels at power plants and from transportation is causing the uptick in nitrogen in the rain. By taking samples of plants in different bogs and analyzing the nitrogen they contained, the scientists found that plants in areas where the pollution was light got 57 percent of their nitrogen from insects, but in areas with heavy pollution that number fell to 22 percent.
The plants are responding to the extra nitrogen by making their leaves less sticky and changing their color to more green instead of insect-attracting red, making bogs where nitrogen pollution is high easy to spot.
This change is actually to the plants' detriment. The plants originally evolved to be carnivorous in order to survive in the low-nitrogen environments of the bogs, but now that the plants are switching their diet they will find it harder to compete with non-carnivorous plants that are equipped better for a high-nitrogen environment.
"In the sites with more nitrogen deposition, these plants now get much more of their nitrogen from their roots, but they still have to bear the residual costs of being carnivorous, and other plants without these will be better able to survive,"said Dr. Jonathan Millett, the report's lead author. "So it's quite likely we'll see less abundance and perhaps local extinctions from carnivorous species. The individual plants get bigger and fitter, but the species as a whole is less well adapted to high-nitrogen environments and will lose out over time."
written by Robert, June 13, 2012
written by Treset, November 11, 2012
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