Sigurdsson, B.D., Thorgeirsson, H. and Linder, S. 2001. Growth and dry-matter partitioning of young Populus trichocarpa in response to carbon dioxide concentration and mineral nutrient availability. Tree Physiology 21: 941-950.
What was done
The authors grew black cottonwood (Populus trichocarpa Torr. & Gray) seedlings for three consecutive growing seasons in closed-top chambers receiving atmospheric CO2 concentrations of 350 and 700 ppm in combination with low and high soil nutrition to determine the effects of elevated CO2 and soil fertility on biomass production in this species. The experiment took place in southern Iceland, where the mean annual air temperature was 4.3°C during the experiment.
What was learned
Atmospheric CO2 enrichment did not significantly affect total seedling biomass when seedlings were concomitantly subjected to low soil fertility. At higher levels of soil fertility, however, elevated CO2 increased total seedling biomass by 47%.
What it means
As the air's CO2 content rises, it is likely that this tree species will exhibit increased growth and biomass production, even in areas where it is extremely cold, but only if soil nutrition is adequate. Indeed, under conditions of low soil fertility in this experiment, atmospheric CO2 enrichment did not elicit a positive growth response in this species. However, in managed plantations were soil nutrition is supplemented with fertilization; it is highly likely this particular tree species will grow increasingly larger as the air's CO2 concentration continues to rise.