Ecology of Crops in Changing CO₂ Concentration

抄録

Under non-limiting water and nutrient supply, prior reviews suggest crops grow about 30% more on the average with a doubling of CO₂ concentration. Reports indicate that water-limiting conditions increase the stimulation of growth by elevated CO₂ more often than they decrease it, but a regression analysis did not reveal significant differences. In contrast, other reports suggest nutrient-limited conditions reduce stimulation of growth by CO₂ enrichment more often than they increase it. Regression analysis of these literature data suggests that on average the CO₂ growth and yield stimulation under nutrient stress were only 74% and 49%, respectively, of the stimulation with adequate nutrients. However, many of the studies were pot or nutrient solution studies which may not represent field conditions. The interaction between CO₂ and temperature appears to be strong and positive, although deleterious effects on harvest index may occur for some species, and increased temperature can shorten he life cycle of determinant crops.