Ce. Owensby, POTENTIAL IMPACTS OF ELEVATED CO2 AND ABOVEGROUND AND BELOWGROUND LITTER QUALITY OF A TALLGRASS PRAIRIE, Water, air and soil pollution, 70(1-4), 1993, pp. 413-424
Increased atmospheric CO2 will likely impact the productivity of arid
and semiarid ecosystems through increased C, N, and water use efficien
cies at the individual plant level. Tallgrass prairie has had increase
d above- and belowground biomass production under elevated CO2, primar
ily due to increased water use efficiency. There is an apparent decrea
sed N requirement to sustain increased productivity in CO2-enriched ta
llgrass prairie, and C:N ratios of plant litter above and below ground
have increased. The tallgrass prairie ecosystem level response to ele
vated CO2 on the C cycle could potentially increase C storage. Reduced
litter quality associated with elevated CO2 in tallgrass prairie has
the potential to reduce decomposition rates, and ruminant digestion ra
te of plant biomass apparently has been lowered. Reduced intake by rum
inants would shunt more of the plant biomass directly into the detrita
l food chain, thereby slowing decomposition further. The potential imp
act is for increased C to be retained as soil organic matter in the ta
llgrass prairie.