Article,
Effects of atmospheric CO2 enrichment on plant growth: the interactive role of air temperature
Agriculture, Ecosystems & Environment, 20 (1): 1--10 (November 1987)
DOI: 10.1016/0167-8809(87)90023-5
Abstract
Comprehensive reviews of the plant science literature indicate that a 300 part per million (ppm) increase in atmospheric carbon dioxide (CO2) concentration generally increases plant growth by approximately 30\%. Working with two species of floating aquatic plants and three terrestrial species, we demonstrate that this stimulatory effect of atmospheric CO2 enrichment is strongly temperature dependent. Indeed, our results suggest that for a 3°C increase in mean surface air temperature (as is generally predicted to result from the 'greenhouse effect' of such an increase in the CO2 content of the air), the growth enhancement factor for such a CO2 increase rises from 1.30 to 1.56. If the non-CO2 trace gas greenhouse effect is equally as strong, as recent model studies suggest, the growth enhancement factor rises still higher to a value of 1.85. On the other hand, our results also indicate that atmospheric CO2 enrichment tends to reduce plant growth at relatively cold air temperatures, i.e. below a daily mean air temperature of approximately 18.5°C. As a result, predicting the ultimate biospheric consequences of a doubling of the Earth's atmospheric CO2 concentration may prove to be much more complex than originally anticipated.
