Elevated Atmospheric CO2 Ameliorates Some Negative Effects of Nitrogen Pollution


Increased nitrogen deposition to terrestrial ecosystems, an outcome of fossil fuel use, often reduces plant species richness (the number of different species in a given area). A 10-year BER-supported field experiment that used the BER-invented Free-Air CO2 Enrichment (FACE) approach to study ecological effects of both elevated nitrogen deposition and elevated atmospheric CO2 concentration, found that elevated CO2 ameliorated the negative effects of nitrogen deposition on plant species richness in a Minnesota grassland. Specifically, the nitrogen deposition treatment reduced species richness by 16% with ambient CO2 levels, but only 8% with a 45% increase in atmospheric CO2 concentration (to a level of about 550 ppm). This new insight will allow more realistic projections of the effects of fossil fuel use on earth’s terrestrial biosphere, and improvements to earth system climate change models.


Reich, P.B. Elevated CO2 reduces losses of plant diversity caused by nitrogen deposition. Science 326:1399-1402.