How does rising atmospheric CO2 affect marine organisms?

Click to locate material archived on our website by topic

Six Years of CO2 Enrichment of a Nutrient-Poor Grassland
Niklaus, P.A., Alphei, J., Ebersberger, D., Kampichlers, C., Kandeler, E. and Tscherko, D.  2003.  Six years of in situ CO2 enrichment evoke changes in soil structure and soil biota of nutrient-poor grassland.  Global Change Biology 9: 585-600.

What was done
The authors enriched the air above plots of a nutrient-poor species-rich calcareous grassland in northwestern Switzerland with an extra 240 ppm of CO2 via a set of novel windscreens that "operated around the clock" except during mid-winter (December-February).

What was learned
Among a number of other findings, the authors report that during the six years of their experiment, above-ground plant biomass accumulation increased in response to CO2 by an average of 21%.  Simultaneously, there was an increase in soil moisture due to CO2-induced reductions in plant transpiration.  They also report that microbial nitrogen (N) pools did not change, "indicating that elevated CO2 did not stimulate net microbial immobilization of N which could have imposed a negative feedback on plant growth [but didn't]."

What it means
As the air's CO2 content continues to climb ever higher, there is a good likelihood the productivity of earth's grasslands, even in nutrient-poor areas, will steadily and consistently increase their productivity, even in areas that may experience slight decreases in precipitation.

Reviewed 4 June 2003