Plants’ ability to absorb increased levels of carbon dioxide
in the air may have been overestimated, a new University of Minnesota study
shows.
The study, published this week in the journal Nature Climate
Change, shows that even though plants absorb large amounts of carbon dioxide
and actually can benefit from higher levels of it, they may not get enough of
the nutrients they need from typical soils to absorb as much CO2 as scientists
had previously estimated. Carbon dioxide absorption is an important factor in
mitigating fossil-fuel emissions.
The study, one of only three such long-term experiments in
the world, is based on 13 years of research at the Cedar Creek Ecosystem
Science Reserve north of the Twin Cities. U of M scientists Peter Reich and
Sarah Hobbie monitored nearly 300 open-air plots planted with perennial grasses
with varying levels of atmospheric carbon dioxide and soil nitrogen.