How does rising atmospheric CO2 affect marine organisms?

Click to locate material archived on our website by topic

Photosynthetic Acclimation of Native Plants to Warming in the Temperate Steppe of Northern China
Niu, S., Li, Z., Xia, J., Han, Y., Wu, M. and Wan, S. 2008. Climatic warming changes plant photosynthesis and its temperature dependence in a temperate steppe of northern China. Environmental and Experimental Botany 63: 91-101.

What was done
Working in Duolun County (a semiarid area located in Inner Mongolia, China), the authors transplanted seedlings of five co-occurring indigenous plants -- two C3 grasses (Stipa krylovii, Agropyron cristatum), two C3 forbs (Artemisia capillaris, Potentilla acaulis) and one C4 grass (Pennisetum centrasiaticum) -- into 11-cm-diameter PVC tubes of 50-cm-length (two individuals of the same species to each of twenty tubes), which they filled with local soil and recessed into the ground to a depth of 45 cm in two 3-m by 4-m plots in mid-May, one of which plots was continuously warmed by about 1C by an infrared heater suspended above the ground from two weeks after transplanting until the end of the growing season in late September, over which period a number of diurnal measurements of photosynthesis were conducted on a variety of clear days at several different leaf chamber temperatures.

What was learned
Niu et al. report that all five species grown under natural conditions in the temperate steppe of northern China acclimated to elevated temperature by increasing the optimum temperature for photosynthesis (TOPT) and the assimilation rate at TOPT by 0.33-0.78C and 4-27%, respectively."

What it means
In light of their findings, the six Chinese researchers concluded that "most of the species in the temperate steppe of northern China could acclimate to a warmer environment." In fact, their results suggest they could actually benefit from it. And with more CO2 in the air, they would doubly benefit. See, in this regard, Growth Response to CO2 with Other Variables (Temperature - Grassland Species) in our Subject Index.

Reviewed 25 June 2008