Monoterpene Emission from Coniferous Trees in Response to Elevated CO sub(2) Concentration and Climate Warming

Experts have hypothesized that high availability of carbon dioxide would boost emissions of monoterpenes to the atmosphere. This theory was developed based on resource allocation theory, which predicts elevated production of plant secondary compounds in the presence of excess levels of C. Tests were enacted to measure the monoterpene emission rates from needles of a range of different conifers grown under different CO sub(2) levels. Samples of Ponderosa pine (Pinus ponderosa Dougl. ex Laws) were raised under a variety of atmospheric CO sub(2) concentrations and soil nitrogen levels. Samples of Douglas fir (Pseudotsuga menziesii (Mirb.) Franco) were raised under a range of different CO sub(2) levels. Samples of Ponderosa pine raised under double ambient CO sub(2) exhibited elevated photosynthetic rates and increased needle starch to N ratios.