MONOTERPENE EMISSION FROM YOUNG SCOTS PINE MAY BE INFLUENCED BY NUTRIENT AVAILABILITY

Monoterpenes (C10H16) are the products of metabolism found in many plants and are most notably emitted by conifers. Many abiotic and biotic factors are known to stimulate monoterpene emissions from conifers, including: temperature, wounding, herbivory, infestation, UV-radiation, O-3 exposure etc. Monoterpenes have been shown to contribute to aerosol and cloud formation, which have a net cooling effect on Earth's radiative balance. Thus, there is a need to explore all the factors that influence monoterpene emissions from forests. One as yet largely unexplored process is the effect of nutrient availability on monoterpene emission. In this study we treated young Scots pine seedlings with fertilizer (NPK and urea) largely and observed a large increase in monoterpene emission compared with unfertilized controls. Measurements at 26 degrees C suggests an emission increase of 0.8 ng g(-1) DW min(-1) per addition of 1 kg N-tot ha(-1) year(-1). These results are important for understanding future trends in monoterpene emission, since nitrogen deposition, as consequence of industrial emissions and agricultural sources, is increasing in the soils of boreal and high altitude temperate forests.