SEASONAL-VARIATIONS OF TERPENE EMISSION FROM TREES AND INFLUENCE OF TEMPERATURE, LIGHT AND CONTACT STIMULATION ON TERPENE EMISSION

Seasonal variations of the leaf oil contents and the amounts of terpen e emission of Cryptomeria japonica, Chamaecyparis obtusa, Abies sachal inensis, Thuja occidentalis, Thuja standishii, Cupressus sempervirens and Cinnamomum japonicum were studied. The leaf oil contents and the a mounts of terpene emission were high in summer and low in winter. It w as suggested that the terpene emission varied with leaf oil production . The amounts of terpene emission from C. obtusa were higher at 30 deg rees C than 15 degrees C either in the light or in the dark and they w ere also higher in the light than in the dark. The amounts of terpene emission increased by the forced emission method by which three seedli ngs on pots were rotated by touching each other's leaves and the amoun ts of terpenes reached 3 to 35 mu g/(g(grams dry weight). h); The indi viduals of varieties of C. obtusa seedlings whose quantities of terpen e emission were high were selected to propagate these individuals.