1985 Volume 35 Issue 2 Pages 215-223
SAWADA, Shinichi (Dept. Biol., Fac. Sci., Hirosaki Univ., Hirosaki, Aomori). 1985. Fundamental studies on dynamics of ethylene in ecosystem. I. Atmospheric ethylene concentrations in a Fagus crenata forest and above paddy fields during burning of agricultural wastes. Jap. J. Ecol., 35 : 215-223. Atmospheric ethylene (C_2H_4) levels were examined in a Fagus crenata forest and above paddy fields during the burning of agricultural wastes in Aomori Prefecture during 1980 and 1981. The C_2H_4 concentrations in the forest showed scarcely diurnal as well as vertical variations during the determination periods in August and September. The average concentrations during 24 hr periods were 1.6 ppb in August and 2.2 ppb in September. In July, at the daytime determinations, the C_2H_4 concentrations in the forest canopy were lower than those below the canopy, whereas, at the nighttime determinations, the vertical changes showed roughly the reverse of those observed at the daytime determinations. The C_2H_4 levels during the 24 hr periods fluctuated in a range of 3.3 to 11.0 ppb. At a height of 1.2 m above the paddy fields during the burning of wastes, the atmospheric C_2H_4 concentration was the highest, a mean value of 77.3 ppb, whereas the concentrations decreased with the increase in height and attained a constant level in the range of 1.1 to 1.2 ppb at heights over 1,200 m above the ground surface. The general C_2H_4 levels in the temperate forest ecosystem and in the boundary layer over the main island of Japan (Honshu), in addition to the effects of the levels observed in the ecosystem on physiological processes in plants, were discussed using the present results and other previous data.
